Miscellany

Jai Ganesh · 2024-07-24 18:55:24

2228) Atacama Desert

Gist

The Atacama Desert is the driest nonpolar desert in the world, and the second driest overall, behind some specific spots within the McMurdo Dry Valleys. It is the only true desert to receive less precipitation than polar deserts, and the largest fog desert in the world.

Atacama Desert, cool, arid region in northern Chile, 600 to 700 miles (1,000 to 1,100 km) long from north to south. Its limits are not exactly determined, but it lies mainly between the south bend of the Loa River and the mountains separating the Salado-Copiapó drainage basins.

Summary

Atacama Desert, cool, arid region in northern Chile, 600 to 700 miles (1,000 to 1,100 km) long from north to south. Its limits are not exactly determined, but it lies mainly between the south bend of the Loa River and the mountains separating the Salado-Copiapó drainage basins. To the north the desert continues to the border of Peru.

A line of low coastal mountains, the Cordillera de la Costa, lies to the west of the desert, and to its east rises the Cordillera Domeyko, foothills of the Andes. The desert consists mainly of salt pans at the foot of the coastal mountains on the west and of alluvial fans sloping from the Andean foothills to the east; some of the fans are covered with dunes, but extensive pebble accumulations are more common.

The coastal chain hovers around 5,000 feet (1,500 metres) or so in elevation with individual peaks reaching to 6,560 feet (2,000 metres). There is no coastal plain. Through much of their extent the mountains terminate abruptly at the sea in cliffs, some of them higher than 1,600 feet (500 metres), making communication difficult between the coastal ports and the interior. In the interior a raised depression extends north and south and forms the high Tamarugal Plain at an elevation of more than 3,000 feet (900 metres). Farther to the east in the western outliers of the Andes, preceded by the Cordillera Domeyko, there are numerous volcanic cones, some exceeding 16,000 feet (4,900 metres) in elevation. Along Chile’s northeastern frontier with Argentina and Bolivia extends the Atacama Plateau, which reaches elevations of 13,000 feet (4,000 metres).

The Atacama Desert forms part of the arid Pacific fringe of South America. Dry subsidence created by the South Pacific high-pressure cell makes the desert one of the driest regions in the world. Along the coast the aridity is also a consequence of the Peru (Humboldt) Current, which is characterized by upwelling (the upward movement of cold water from the depths of the ocean); the resulting cold water at the surface causes a thermal inversion—cold air at sea level and stable warmer air higher up. This condition produces fog and stratus clouds but no rain. Rains fall in Iquique or Antofagasta only when powerful southern fronts break into the subsidence area. Temperatures in the desert are relatively low compared with those in similar latitudes elsewhere. The average summer temperature at Iquique is only 66 °F (19 °C) and at Antofagasta 65 °F (18 °C).

The original inhabitants of the region were Atacameño, an extinct Indian culture, different from the Aymara to the north and the Diaguita to the south. For much of the 19th century, the desert was the object of conflicts among Chile, Bolivia, and Peru because of its mineral resources, particularly sodium nitrate deposits located northeast of Antofagasta and inland from Iquique. Much of the area originally belonged to Bolivia and Peru, but the mining industry was controlled by Chilean and British interests, which were strongly supported by the Chilean government. From the War of the Pacific (1879–83), Chile emerged victorious. The Treaty of Ancón (1883) gave Chile permanent ownership of sectors previously controlled by Peru and Bolivia, the latter losing its whole Pacific coastline.

The area proved to be one of the chief sources of Chile’s wealth until World War I. Nitrate deposits in the central depression and in several basins of the coastal range were systematically mined after the mid-19th century. Ports were built at Iquique, Caldera, Antofagasta, Taltal, Tocopilla, Mejillones, and, farther north, Pisagua, and railroads penetrated the mountain barriers to the interior. Prior to World War I, Chile had a world monopoly on nitrate; in some years 3,000,000 tons were extracted, and the taxes on its export amounted to half the government’s revenues. The development of synthetic methods of fixing nitrogen have since reduced the market to a regional one. Some sulfur is still mined in the high Cordillera. The region’s chief source of revenue, however, is copper mining at Chuquicamata in the Calama basin.

Some farming is done in the desert’s river oases, but this supports only a few thousand traditional cultivators. Lemons are grown at Pica, and a variety of products are cultivated on the shores of the salt marshes at San Pedro de Atacama. At Calama, near Chuquicamata, water from the Loa River irrigates potato and alfalfa fields.

Details

The Atacama Desert (Spanish: Desierto de Atacama) is a desert plateau located on the Pacific coast of South America, in the north of Chile. Stretching over a 1,600-kilometre-long (1,000-mile) strip of land west of the Andes Mountains, it covers an area of 105,000 {km}^2 (41,000 sq mi), which increases to 128,000 {km}^2 (49,000 sq mi) if the barren lower slopes of the Andes are included.

The Atacama Desert is the driest nonpolar desert in the world, and the second driest overall, behind some specific spots within the McMurdo Dry Valleys. It is the only true desert to receive less precipitation than polar deserts, and the largest fog desert in the world. The area has been used as an experimentation site for Mars expedition simulations due to its similarities to the Martian environment.

The constant temperature inversion caused by the cool north-flowing Humboldt Ocean current and the strong Pacific anticyclone contribute to the extreme aridity of the desert. The most arid region of the Atacama Desert is situated between two mountain chains, the Andes and the Chilean Coast Range, which are high enough to prevent moisture advection from either the Pacific or the Atlantic Ocean, creating a two-sided rain shadow effect.

Setting

According to the World Wide Fund for Nature, the Atacama Desert ecoregion occupies a continuous strip for nearly 1,600 kilometres (1,000 mi) along the narrow coast of the northern third of Chile, from near Arica (18°24′S) southward to near La Serena (29°55′S). The National Geographic Society considers the coastal area of southern Peru to be part of the Atacama Desert and includes the deserts south of the Ica Region in Peru. However, other sources consider that the part of the desert in Peru is a different ecosystem, and should properly be named as Pampas de la Joya desert.

Peru borders it on the north and the Chilean Matorral ecoregion borders it on the south. To the east lies the less arid Central Andean dry Puna ecoregion. The drier portion of this ecoregion is located south of the Loa River between the parallel Sierra Vicuña Mackenna and the Cordillera Domeyko. To the north of the Loa lies the Pampa del Tamarugal.

The Coastal Cliff of northern Chile west of the Chilean Coast Range is the main topographical feature of the coast. The geomorphology of the Atacama Desert has been characterized as a low-relief bench "similar to a giant uplifted terrace" by Armijo and co-workers. The intermediate depression (or Central Valley) forms a series of endorheic basins in much of the Atacama Desert south of latitude 19°30'S. North of this latitude, the intermediate depression drains into the Pacific Ocean.

In December 2023, scientists, for the first time, reported on a recently discovered area in the territory of Puna de Atacama, which may have similarities to Earth during the Archean eon and thus to the environment of the first life forms on Earth. It could as well be similar to conceivably-hospitable conditions on the planet Mars during earlier Martian times.

Climate

The almost total lack of precipitation is the most prominent characteristic of the Atacama Desert.

Aridity

The Atacama Desert is commonly known as the driest place in the world, especially the surroundings of the abandoned Yungay mining town, where the University of Antofagasta Desert Research Station is located, in Antofagasta Region, Chile. The average rainfall is about 15 mm (0.6 in) per year, although some locations only receive 1 to 3 mm (0.04 to 0.12 in) in a year. Moreover, some weather stations in the Atacama have never received rain. Periods up to four years have been registered with no rainfall in the central sector, delimited by the cities of Antofagasta, Calama, and Copiapó, in Chile. Evidence suggests that the Atacama may not have had any significant rainfall from 1570 to 1971.

The Atacama Desert may be the oldest desert on earth, and has experienced hyper aridity since at least the Middle Miocene, since the establishment of a proto-Humboldt current in conjunction with the opening of the Tasmania-Antarctic passage ca. 33 Ma. The opening of the Tasmania-Antarctic passage allowed for cold currents to move along the west coast of South America, which influenced the availability of warm humid air to travel from the Amazon Basin to the Atacama. Though there was a general lack of humid air after 33 Ma, there were punctuated intervals of increased humidity, such as between around 10.86 and 6.4 Ma, when the Tiliviche Palaeolake existed before turning into a salar sometime before the Middle Pliocene. The long history of aridity raises the possibility that supergene mineralisation, under the appropriate conditions, can form in arid environments, instead of requiring humid conditions. The presence of evaporite formations suggests that in some sections of the Atacama Desert, arid conditions have persisted for the last 200 million years (since the Triassic).

Aridity in Atacama Desert predates the rise of the Central Andes, yet hyper-aridity is generally thought to have resulted from the rise of the Andes. As such it is hypothesised it had climatic conditions akin to the Namib Desert prior to the rise of the mountains.

The Atacama is so arid that many mountains higher than 6,000 m (20,000 ft) are completely free of glaciers. Only the highest peaks (such as Ojos del Salado, Monte Pissis, and Llullaillaco) have some permanent snow coverage.

The southern part of the desert, between 25° and 27°S, may have been glacier-free throughout the Quaternary (including during glaciations), though permafrost extends down to an altitude of 4,400 m (14,400 ft) and is continuous above 5,600 m (18,400 ft). Studies by a group of British scientists have suggested that some river beds have been dry for 120,000 years. However, some locations in the Atacama receive a marine fog known locally as the camanchaca, providing sufficient moisture for hypolithic algae, lichens, and even some cacti—the genus Copiapoa is notable among these.

Geographically, the aridity of the Atacama is explained by its being situated between two mountain chains (the Andes and the Chilean Coast Range) of sufficient height to prevent moisture advection from either the Pacific or the Atlantic Oceans, a two-sided rain shadow.

Despite modern views of the Atacama Desert as fully devoid of vegetation, in pre-Columbian and colonial times a large flatland area there known as Pampa del Tamarugal was a woodland, but demand for firewood associated with silver and saltpeter mining in the 18th and 19th centuries resulted in widespread deforestation.

Comparison to Mars

In a region about 100 km (60 mi) south of Antofagasta, which averages 3,000 m (10,000 ft) in elevation, the soil has been compared to that of Mars. Owing to its otherworldly appearance, the Atacama has been used as a location for filming Mars scenes, most notably in the television series Space Odyssey: Voyage to the Planets.

In 2003, a team of researchers published a report in which they duplicated the tests used by the Viking 1 and Viking 2 Mars landers to detect life and were unable to detect any signs in Atacama Desert soil in the region of Yungay. The region may be unique on Earth in this regard and is being used by NASA to test instruments for future Mars missions. The team duplicated the Viking tests in Mars-like Earth environments and found that they missed present signs of life in soil samples from Antarctic dry valleys, the Atacama Desert of Chile and Peru, and other locales. However, in 2014, a new hyperarid site was reported, María Elena South, which was much drier than Yungay and, thus, a better Mars-like environment.

In 2008, the Phoenix Mars Lander detected perchlorates on the surface of Mars at the same site where water was first discovered. Perchlorates are also found in the Atacama and associated nitrate deposits have contained organics, leading to speculation that signs of life on Mars are not incompatible with perchlorates. The Atacama is also a testing site for the NASA-funded Earth–Mars Cave Detection Program.

On 21 February 2023, scientists reported the findings of a "dark microbiome" of unfamiliar microorganisms in the Atacama Desert.

Extreme weather events

In June 1991, Antofagasta and Taltal and inland regions as far as Calama received unusual rainfall leading to formation of a series of mudflows that killed 91 persons.

In 2012, the altiplano winter brought floods to San Pedro de Atacama.

On 25 March 2015, heavy rainfall affected the southern part of the Atacama Desert. Resulting floods triggered mudflows that affected the cities of Copiapo, Tierra Amarilla, Chanaral, and Diego de Almagro, causing the deaths of more than 100 people.

Jai Ganesh · 2024-07-25 13:45:29

2229) Kaffir lime

Details

Citrus hystrix, called the kaffir lime, Thai lime or makrut lime, is a citrus fruit native to tropical Southeast Asia.

Its fruit and leaves are used in Southeast Asian cuisine, and its essential oil is used in perfumery. Its rind and crushed leaves emit an intense citrus fragrance.

Description

C. hystrix is a thorny shrub or small tree, 2 to 11 metres (6 to 35 ft) tall, with aromatic and distinctively shaped "double" leaves. These hourglass-shaped leaves comprise the leaf blade plus a flattened, leaf-like stalk (botanically, a winged petiole). The fruit is rough and green and ripens to yellow; it is distinguished by its bumpy exterior and small size, approximately 4 cm (2 in) wide. The fruits have thick skins (pericarps) and taste very acidic and slightly bitter. Flowers can have four to five petals that are white in color and are fragrant.

History

Pierre Sonnerat (1748–1814) collected specimens of it in 1771–72, and it appears in Lamarck's Encyclopédie Méthodique (1796).

Makrut lime appears in texts under the name of kaffir lime in 1868, in Ceylon, where rubbing the juice onto legs and socks prevents leech bites. This could be a possible origin of the name leech lime.

Description

C. hystrix is a thorny shrub or small tree, 2 to 11 metres (6 to 35 ft) tall, with aromatic and distinctively shaped "double" leaves. These hourglass-shaped leaves comprise the leaf blade plus a flattened, leaf-like stalk (botanically, a winged petiole). The fruit is rough and green and ripens to yellow; it is distinguished by its bumpy exterior and small size, approximately 4 cm (2 in) wide. The fruits have thick skins (pericarps) and taste very acidic and slightly bitter. Flowers can have four to five petals that are white in color and are fragrant.

Uses:

Culinary

C. hystrix leaves are used in Southeast Asian cuisines such as Indonesian, Laotian, Cambodian, and Thai. The leaves are the most frequently used part of the plant, fresh, dried, or frozen. The leaves are widely used in Thai cuisine (for dishes such as tom yum) and Cambodian cuisine (for the base paste "krueng"). The leaves are used in Vietnamese cuisine to add fragrance to chicken dishes and to decrease the pungent odor when steaming snails. Also, in Vietnamese villages that harvest silkworms, the silkworms in the pupa stage are stir fried with the kaffir lime leaves. The leaves are used in Indonesian cuisine (especially Balinese cuisine and Javanese cuisine) for foods such as soto ayam and are used along with Indonesian bay leaf for chicken and fish. They are also found in Malaysian and Burmese cuisines.

The rind (peel) is commonly used in Lao and Thai curry paste, adding an aromatic, astringent flavor. The zest of the fruit, referred to as combava, is used in creole cuisine to impart flavor in infused rums and rougails in Mauritius, Réunion, and Madagascar. In Cambodia, the entire fruit is crystallized/candied for eating.

Medicinal

The juice and rinds of the peel are used in traditional medicine in some Asian countries; the fruit's juice is often used in shampoo and is believed to kill head lice.

Other uses

The juice is used as a cleanser for clothing and hair in Thailand and occasionally in Cambodia. Lustral water mixed with slices of the fruit is used in religious ceremonies in Cambodia.

Makrut lime oil is used as raw material in many fields, including pharmaceutical, agronomic, food, sanitary, cosmetic, and perfume industries. It is also used extensively in aromatherapy and as an essential ingredient in various cosmetic and beauty products.

Cultivation

C. hystrix is grown worldwide in suitable climates as a garden shrub for home fruit production. It is well suited to container gardens and for large garden pots on patios, terraces, and in conservatories.

Main constituents

The compound responsible for the characteristic aroma was identified as (–)-(S)-citronellal, which is contained in the leaf oil up to 80 percent; minor components include citronellol (10 percent), nerol and limonene.

From a stereochemical point of view, it is remarkable that makrut lime leaves contain only the (S) stereoisomer of citronellal, whereas its enantiomer, (+)-(R)-citronellal is found in both lemon balm and (to a lesser degree) lemon grass, (however, citronellal is only a trace component in the latter's essential oil).

Toxicity

C. hystrix contains significant quantities of furanocoumarins, in both the peel and the pulp. Furanocoumarins are known to cause phytophotodermatitis, a potentially severe skin inflammation. Cases of phytophotodermatitis induced by external use of C. hystrix have been reported.

Makrut lime fruit peel contains an essential oil comparable to lime fruit peel oil; its main components are limonene and β-pinene.

Additional Information

The Kaffir lime (Citrus hystrix DC., Rutaceae), also known as kieffer lime, makrut or magrood, is a citrus fruit native to Indonesia. It is widely grown worldwide as a garden shrub. It is usually grown for its fruit, the lime. The leaves are used for cooking. Vegetable oil obtained from the leaves is used to make perfumes.

The plant

The plant is a very thorny bush with aromatic leaves. The oil obtained from the rind of the fruit can be used as an insecticide. The plant is well suited to being grown in a container. The green fruits are different from other limes because of their bumpy and rough exterior. They are also quite small, about 4 centimetres across. The leaves are shaped like an hourglass. The leaves and the leaf-shaped stem are widely used in the cuisine of Cambodia, Thailand and Laos.

Citrus x hystrix leaves are also popular in Cambodia but less so in Vietnam. Malay, Burmese and Indonesian (especially Balinese and Javanese; see also Indonesian bay leaf) cuisines use them sporadically with chicken and fish.

The leaves can be used fresh or dried and can be stored frozen.

Although the most common product of the Citrus x hystrix tree is its leaves (which give a sharp Lime/neroli flavour to Cambodian base paste known as Krueng, Thai dishes such as tom yum and Indonesian food such as sayur assam - literally sour vegetables), the juice and rind of the small, dark-green gnarled fruit (known as jeruk obat - literally medicine citrus) are used in traditional Indonesian medicine.

The zest is widely used in Creole cuisine and to impart flavour to "arranged" rums on Réunion and Madagascar.

Jai Ganesh · 2024-07-26 00:12:08

2230) Horse Management

Gist

A building in which horses are kept, fed, and cared for. Stable is a building where horses are kept.
She rode the horse back to the stable. A horse stable.

Summary

Horses were among the last species of livestock to be domesticated. Domestication took place at least as early as 3000 BCE, probably in the Near East. The wild math, which when domesticated is usually called a donkey, was first domesticated in Egypt about 3400 BCE.

Breeds

The Arabian, the oldest recognized breed of horse in the world, is thought to have originated in Arabia before 600 CE. Though its history is lost in the past, the breed probably descended from the Libyan horse, which in turn was probably preceded by horses of similar characteristics in Assyria, Greece, and Egypt as early as 1000 BCE. The Arabian may be bay, gray, chestnut, brown, black, or white in hair colour but always has a black skin. It ranges from 14.1 to 15.1 hands (4.7 to 5.0 feet, or 1.4 to 1.5 metres) in height. The Arabian horse has one lumbar vertebra less than other breeds of horse and is characterized by the high carriage of its head, long neck, and spirited action.

The Thoroughbred racing horse is descended from three desert stallions brought to England between 1689 and 1724; all of the Thoroughbreds of the world today trace their ancestry to one of these stallions.

The American Saddle Horse, which originated in the United States, was formed by crossing Thoroughbreds, Morgans, and Standardbreds on native mares possessing an easy gait. The American Saddle Horse is 15 to 16 hands (5 to 5.3 feet, or 1.5 to 1.6 metres) in height. Its colours are bay, brown, black, gray, and chestnut. There are two distinct types of the American Saddle Horse: three-gaited and five-gaited. The three natural gaits are walk, trot, and canter. Three-gaited saddle horses are shown with a short tail and cropped mane. They often have slightly less style and finish than the five-gaited horse. The five-gaited saddle horse has the three natural gaits plus the rack and a slow gait, which is usually a stepping pace. The American Saddle Horse is also used as a fine harness horse mainly for show.

The American Quarter Horse traces to the Thoroughbred, and includes the blood of other breeds, such as the Morgan, the American Saddle Horse, and several strains of native horses. This fast, muscular horse has been raced, ridden in rodeos, and used for herding cattle.

The typical Quarter Horse is 15 to 16 hands tall and is of powerful build, suitable for both racing and the rough life of a cow pony. This horse is noted for its intelligence, easy disposition, and cow sense.

The Tennessee Walking Horse, or plantation horse, traces mainly to the Standardbred but also includes Thoroughbred and American Saddle Horse blood. The Tennessee Walking Horse is noted for its running walk, a slowgliding gait in which the hind foot oversteps the print of the front foot by as much as 24 inches (600 millimetres). This breed is 15.2 to 16 hands high and is bay, black, chestnut, roan, or gray in colour.

The Morgan traces directly to “the Justin Morgan horse,” foaled in 1793, of unknown breeding but no doubt tracing to Arabian stock. A dark bay in colour, Morgan stood 14 hands high and weighed 950 pounds (430 kilograms). He was a heavily muscled, short-legged horse of great style, quality, and endurance. He is the world’s best example of prepotency, since he alone founded the Morgan breed. The Morgan is used for both riding and driving. It ranges from 14 to 16 hands in height and resembles the Arabian in size, conformation, quality, and endurance.

The American Standardbred originated around New York City during the first half of the 19th century from Thoroughbred, Morgan, Norfolk Trotter, Arabian, Barb, and pacers of mixed breeding. The modern Standardbred is smaller than the Thoroughbred, ranging from 15 to 16 hands in height and averaging about 15.2 hands. In racing condition it weighs from 900 to 1,000 pounds (410–450 kilograms). Stallions in stud condition average from 1,100 to 1,200 pounds (500–545 kilograms). Compared with the Thoroughbred, the Standardbred is longer-bodied, shorter-legged, heavier-boned, and stockier in build. Prevailing colours are bay, brown, and chestnut.

Draft horses have largely been supplanted by trucks and tractors in the developed countries of the world. Major draft breeds include the Percheron, developed in France; the Clydesdale of Scotland; the Shire of England; the Suffolk of England; and the Belgian of Belgium. These breeds range from 151/2 to 17 hands in height at the withers; at maturity the mares weigh from 1,600 to 2,000 pounds (720–900 kilograms) and the stallions from 1,900 to 2,200 pounds (860–1000 kilograms).

The more popular pony breeds are the Shetland, which originated in the Shetland Islands, and the Hackney, of English origin. Ponies must be under 14.2 hands in height at the withers and are used both for show and for children’s pleasure.

Details

A stable is a building in which livestock, especially horses, are kept. It most commonly means a building that is divided into separate stalls for individual animals and livestock. There are many different types of stables in use today; the American-style barn, for instance, is a large barn with a door at each end and individual stalls inside or free-standing stables with top and bottom-opening doors.The term "stable" is additionally utilised to denote a collection of animals under the care of a single owner, irrespective of their housing or whereabouts.

The exterior design of a stable can vary widely, based on climate, building materials, historical period and cultural styles of architecture. A wide range of building materials can be used, including masonry (bricks or stone), wood and steel. Stables also range widely in size, from a small building housing one or two animals to facilities at agricultural shows or race tracks that can house hundreds of animals.

History

The stable is typically historically the second-oldest building type on the farm. The world's oldest horse stables were discovered in the ancient city of Pi-Ramesses in Qantir, in Ancient Egypt, and were established by Ramesses II (c. 1304–1213 BC). These stables covered approximately 182,986 square feet, had floors sloped for drainage, and could contain about 480 horses. Free-standing stables began to be built from the 16th century. They were well built and placed near the house because these animals were highly valued and carefully maintained. They were once vital to the economy and an indicator of their owners' position in the community. Relatively few examples survive of complete interiors (i.e. with stalls, mangers and feed racks) from the mid-19th century or earlier.

Traditionally, stables in Great Britain had a hayloft on their first (i.e. upper) floor and a pitching door at the front. Doors and windows were symmetrically arranged. Their interiors were divided into stalls and usually included a large stall for a foaling mare or sick horse. The floors were cobbled (or, later, bricked) and featured drainage channels. An outside stone stairway constructed against the side of the building was common for reaching the upper level.

Horses

For horses, stables are often part of a larger complex which includes trainers, vets and farriers.

Other uses

The word stable is also used metonymically to refer to the collection of horses that the building contains (for example, the college's stable includes a wide variety of breeds) and even, by extension, metaphorically to refer to a group of people—often (but not exclusively) athletes—trained, coached, supervised or managed by the same person or organisation. For example, art galleries typically refer to the artists they represent as their stable of artists. Analogously, car enthusiast magazines sometimes speak of collectible cars in this way, referring to the cars in a collector's stable (most especially when the metaphor can play on the word association of pony cars).

Historically, the headquarters of a unit of cavalry, not simply their horses' accommodation, was known as a "stable".

Additional Information

There are many aspects to horse management. Horses, ponies, mules, donkeys and other domesticated equids require attention from humans for optimal health and long life.

Living environment

Horses require both shelter from natural elements like wind and precipitation, as well as room to exercise. Worldwide, horses and other equids usually live outside with access to shelter for protection from the elements. In some cases, animals are kept in a barn or stable for ease of access by managers, or for protection from the weather for various reasons. For horse owners who do not own their own land, fields and barns can be rented from a private land owner or space for an individual horse may be rented from a boarding farm. Horses that are not on full-time turnout in a field or pasture normally require some form of regular exercise, whether it is being ridden, longed or turned out for free time. However, if a horse is ill or injured it may need to be confined to a stable, usually in a box stall.

As equines are herd animals, most have better mental behavior when in proximity to other equine company. However, this is not always possible, and it has been known for companionship bonds to develop between horses and cats, goats and other species. There are exceptions. Some horses, particularly stallions are often kept separated from other horses, particularly other males they may challenge for dominance. For safety and monitoring, Mares may be separated from a herd prior to foaling.

Horses require access to clean fresh water at all times, and access to adequate forage such as grass or hay. Unless an animal can be fully maintained on pasture with a natural open water source, horses must be fed daily. As horses evolved as continuous grazers, it is better to feed small amounts of feed throughout the day than to feed a large amount at one time.

Horses in blankets

In the winter, horses grow a heavy hair coat to keep warm and usually stay warm if well-fed and allowed access to shelter. But if kept artificially clipped for show, or if under stress from age, sickness or injury, a horse blanket may need to be added to protect the horse from cold weather. In the summer, access to shade is well-advised.

Pastures

If a horse is kept in a pasture, the amount of land needed for basic maintenance varies with climate, an animal needs more land for grazing in a dry climate than in a moist one. An average of between one and 3 acres (12,000 m^2) of land per horse will provide adequate forage in much of the world, though hay or other feed may have to be supplemented in winter or during periods of drought. To lower the risk of laminitis, horses also may need to be removed from lush, rapidly changing grass for short periods in the spring and fall (autumn), when the grass is particularly high in non-structural carbohydrates such as fructans. Horses turned out to pasture full-time still need to be checked frequently for evidence of injury, parasites, sickness or weight loss.

If the terrain does not provide natural shelter in the form of heavy trees or other windbreaks, an artificial shelter must be provided; a horse's insulating hair coat works less efficiently when wet or when subjected to wind, horses that cannot get away from wind and precipitation put unnecessary energy into maintaining core body warmth and may become susceptible to illness.

Horses cannot live for more than a few days without water. Therefore, even in a natural, semi-feral setting, a check every day is recommended; a stream or irrigation source can dry up, ponds may become stagnant or develop toxic blue-green algae, a fence can break and allow escape, poisonous plants can take root and grow; windstorms, precipitation, or even human vandalism can create unsafe conditions.

Pastures should be rotated when plants are grazed down to avoid overgrazing or deterioration of pasture quality. Manure management is also improved by pasture rotation; horses will not eat grass that contains too much of their own manure and such areas are a breeding ground for parasites. Decomposition of the manure needs to be allowed while the horses are kept in an alternative paddock.

Fences and pens

Horses evolved to live on prairie grasslands and to cover long distances unfettered by artificial barriers. Therefore, when fenced in, accident potential must be considered. Horses will put their heads and legs through fences in an attempt to reach forage on the other side. They may run into fences if chased by another animal, or even when running at play if the fence (such as a wire fence) is not particularly visible. The smaller the area, the more visible and substantial a fence needs to be.

For exercise alone, a pen, run, corral or "dry lot" without forage can be much smaller than a pasture, and this is a common way that many horses are managed; kept in a barn with a turnout run, or in a dry lot with a shelter, feeding hay, allowing either no pasture access, or grazing for only a few hours per day. Outdoor turnout pens range greatly in size, but 12 feet (4 m) by 20 to 30 feet (9 m) is a bare minimum for a horse that does not get ridden daily. To gallop for short stretches, a horse needs a "run" of at least 50 to 100 feet (30 m). When kept in a dry lot, a barn or shelter is a must. If kept in a small pen, a horse needs to be worked regularly or turned out in a larger area for free exercise.

Fences in pens must be sturdy. In close quarters, a horse may contact the fence frequently. Wire is very dangerous in any small pen. Pens are often made of metal pipe, or wood. Larger pens are sometimes enclosed in closely woven mesh, sometimes called "no climb" fencing. However, if a wire mesh is used in a small pen, the openings must be too small for a horse hoof to pass through.

Types of fencing

Over vast areas, barbed wire is often seen in some parts of the world, but it is the most dangerous fencing material that can be used around horses, even in a large pasture. If a horse is caught in barbed wire, it can quickly become severely hurt, often leaving lasting scars or even permanent injuries. Horse management books and periodicals are nearly universal in stating that barbed wire should never be used to contain horses. However, this advice is widely ignored, particularly in the western United States.

Various types of smooth wire fencing, particularly when supported by a strand of electric fence, can be used to enclose a large pasture of several acres, and is one of the least expensive fencing options. A wire fence should have at least four, preferably five strands to provide adequate security. However, even without sharp barbs, wire has the highest potential for horses to become tangled in the fence and injured. If used, it must be properly installed and kept tight through regular maintenance. Visibility is also an issue; a horse galloping in an unfamiliar pasture may not see a wire fence until it is too late to stop.

Woven mesh wire is safer but more expensive than strands of smooth wire. It is more difficult to install, and has some visibility issues, but horses are less likely to become tangled in it or be injured if they run into it. Adding a top rail of wood or synthetic material increases visibility of the fence and prevents it from being bent by horses reaching over it. A strand of electric fence may also keep horses from pushing on a mesh fence. Mesh fencing needs to be heavy-gauge wire, woven, not welded, and the squares of the mesh should be too small for a horse to put a foot through. "Field fence" or "no-climb" fence are safer designs than more widely woven "sheep fence." Chain link fence is occasionally seen, but horses can bend chain link almost as easily as a thinner-gauge wire, so the additional expense is often not justified by any gain over good-quality woven wire.

Electric fence comes in many styles of wire, rope and webbing, and is particularly useful for internal division of pastures. It carries only a mild charge that causes a noticeable shock, but no permanent injury to animals or people. It is relatively inexpensive and is easy to install, but if electricity fails, it is easily broken. It is excellent both as a temporary fence and, in single strands, as a top or middle barrier to keep horses away from conventional fencing. There is some danger that horses can become tangled in an electric fence, though because the materials are finer, it usually breaks, stopping the current, though injuries are still possible. Because electricity can fail, it should not be the sole fencing used on property boundaries, particularly next to roads, though a strand on top may be used to keep a horse from leaning over a fence made of other materials. Nor should it be used alone in small pens where horses may accidentally bump into it on a regular basis. However, small single-horse enclosures are sometimes seen at endurance riding competition, where temporary fencing must be set up in remote areas. In residential areas, warning signs should be posted on any boundary fences with electrified sections to keep people from touching the fence and accidentally being shocked.

Wood is the "classic" form of horse fencing, either painted planks or natural round rails. It is one of the safest materials for containing horses. Wood or a synthetic material with similar properties is the best option for small paddocks, pens and corrals. It can be used to fence pastures and has some ability to give or break if a horse collides with it. However, wood is expensive, high maintenance and not completely without safety concerns; boards can splinter, nails can stick out and cause lacerations. Wood-like synthetics are even more expensive, but are often safer and lower maintenance.

Cable of various sorts is sometimes used for horse fencing, and, especially if combined with a top rail or pipe or wood, can be reasonably safe. However, if cable is not kept tight, like wire, horses can be tangled in it. However, it not only cannot break but unlike wire, it also cannot easily be cut by humans. Its advantage over wire is that it poses less of a risk of entanglement. It is often less expensive than wood or pipe, has some give if a horse runs into it, and requires relatively little maintenance.

Metal pipe is often used for fences instead of wood and if properly installed, can be fairly safe in the right circumstances. Pipe is often the most expensive fencing option, but is low maintenance and is very strong. Pipe will generally not give or break if it is run into or if the horse puts a foot through it, which can itself be a potential injury risk; horse owners debate the relative merits and dangers of pipe versus wood for horse fencing. Usually pipe is most suitable for very small areas such as pens where a horse may often bump or test the fence, but will not be at risk of colliding with the fence at full speed.

Barns and stables

Horses are sometimes kept indoors.

A horse can be kept in a box stall. Mares with foals often are kept in double stalls.

Feeding

A horse or pony needs approximately 1.5% to 2.5% of its body weight in food per day, depending on its age and level of work.

Grooming

Horses groomed regularly have healthier and more attractive coats. Many horse management handbooks recommend grooming a horse daily, though for the average modern horse owner, this is not always possible. However, a horse should always be groomed before being ridden to avoid chafing and rubbing of dirt and other material, which can cause sores on the animal and also grind dirt into horse tack. Grooming also allows the horse handler to check for injuries and is a good way to gain the trust of the animal.

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Jai Ganesh · 2024-07-27 00:09:46

2231) Bullion

Bullion

Gist

Bullion is non-ferrous metal that has been refined to a high standard of elemental purity.

Summary

Bullion, the name applied to gold, silver, and platinum considered solely as metal without regard to any value arising from its form as coins or ornaments. The bullion value of a coin is determined by its weight, fineness (proportion of precious metal to total weight), and the current price of the metal.

When most countries dropped the silver standard for currency in the early 20th century, the silver bullion in subsidiary coins became worth considerably less than face value. The exception to this rule occurred when an issuing government inflated its paper currency and reduced its purchasing power to the point that it became profitable to melt coins for their bullion value. In the United States, the rising price of silver in the mid-1960s made it necessary to reduce the silver content of subsidiary coins to prevent their being melted down for their bullion value. Gold coins enjoy a value established by world markets for their bullion content.

The bulk of the world’s monetary gold is held in bars rather than coins, and it is kept as a reserve by countries and banks even though the era of the gold standard has passed. Individuals hoard gold when they fear either monetary or political instability. In doing so they lose any profit they might gain by investing the money and they incur storage costs. They also risk confiscation by the government of any profits resulting from currency devaluation, such as occurred during the Great Depression of the early 1930s. Nevertheless, the tangibility and ease of convertability of bullion made it an attractive option for some investors.

Details

Bullion is non-ferrous metal that has been refined to a high standard of elemental purity. The term is ordinarily applied to bulk metal used in the production of coins and especially to precious metals such as gold and silver. It comes from the Anglo-Norman term for a melting-house where metal was refined, and earlier from French bouillon, "boiling". Although precious metal bullion is no longer used to make coins for general circulation, it continues to be held as an investment with a reputation for stability in periods of economic uncertainty. To assess the purity of gold bullion, the centuries-old technique of fire assay is still employed, together with modern spectroscopic instrumentation, to accurately determine its quality.

As investment

The specifications of bullion are often regulated by market bodies or legislation. In the European Union, the minimum purity for gold to be referred to as "bullion", which is treated as investment gold with regard to taxation, is 99.5% for gold bullion bars and 90% for bullion coins. Investors may choose to purchase physical bullion for several reasons – to attempt to hedge against currency risks, inflation risks, geopolitical risks, or to add diversification to an investment portfolio.

London bullion market

The London bullion market is an over-the-counter market for wholesale trading of gold and silver. The London Bullion Market Association (LBMA) coordinates activities of its members and other participants in the London bullion market. The LBMA sets and promotes quality standards for gold and silver bullion bars. The minimum acceptable fineness of the Good Delivery Bars is 99.5% for gold bars and 99.9% for silver bars. Bars with a purity less than these may not be referred to as "bullion".

Coins

Bullion coins are contemporary precious metal coins minted by official agencies for investment purposes. Some bullion coins have been used as currency throughout the 20th century, such as the Maria Theresa thaler and the Krugerrand. Modern bullion coins generally do not enter common circulation despite having legal tender status and nominal face value. Some modern bullion coins are produced as business strike and collectible proof and uncirculated versions, such as the American Silver Eagle and American Gold Eagle coins. Private mint strikes called bullion rounds, bullion wafers or bullion bars are typically sold at prices slightly above the underlying prevailing precious metals spot price commensurate with their precious metal content, whereas collectible versions are sold at a significant premium over their precious metal bullion melt value. In some cases, the grade and mintages of privately struck rounds, bars or wafers can affect their value as a collectible too, they can at times be considered collectible numismatic pieces rather than bullion items.

Uses

Professional market participants participate in the bullion markets, such as banks, fabricators, refiners, and vault operators or transport companies, as well as brokers. They provide facilities for the refining, melting, assaying, transporting, trading and vaulting of gold and silver bullion. Other professional parties such as investment companies and jewelers use bullion in the context of products or services which they produce or offer to customers. Shares of the world's largest gold exchange-traded fund, the SPDR Gold Shares, represent a gold spot price mimicking derivative although shareholders in popular gold ETFs such as GLD are almost always unsecured creditors, meaning they own no vaulted gold bullion potentially underlying the exchange-traded fund (ETF).

Investors often prefer to own bullion outright over ETFs due to the minimization of counter-party risks inherent. Private individuals use bullion as an investment or as a store of value. Gold bullion and silver bullion are the most important forms of physical precious metals investments. Bullion investments can be considered as insurance against inflation or economic turmoil, their sole direct counterparty risk is theft or government confiscation. Compared to numismatic coins, bullion bars or bullion coins can typically be purchased and traded at lower price premiums over the fluctuating spot price and their trading bid/ask spreads or buy/sell price differences are closer to the values of the contained precious metals.

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Jai Ganesh · 2024-07-27 17:56:16

2232) User Group

Gist

User groups are a collection of users who perform a similar task. For example, a group of customer service representatives might be put in a Customer Service Representative user group. Users can belong to multiple user groups to which permissions are assigned.

Closed User Groups are groups of GSM mobile telephone subscribers who can only make calls and receive calls from members within the group. This service is NOT applicable to Short messaging service (SMS).

Summary

Closed User group (CUG) is a supplementary service provided by the mobile operators to mobile subscribers who can make and receive calls from any member associated within the group. This service is applicable for SMS also. There will be administrative owner who will be responsible for invoicing. Irrespective of this a CUG member can make and receive calls to and from other networks outside the CUG group too; although calls outside a CUG group may not be invoiced by the administrative owner.

A subscriber may:

* be a member of more than one but not more than ten closed user groups;
* be permitted to make calls outside of the closed user group (outgoing access);
* be permitted to receive calls from outside of the closed user group (incoming access);
* be allowed to make emergency calls irrespective of the group subscription.
* be allowed to make call inside the closed user group member like incoming and outgoing also.

If the user is a member of multiple closed user groups there will be a preferred CUG assigned by the network that will be used by default. However, it is possible on a per-call basis to specify a different closed user group (of which the user is a member) for the call. It is also possible on a per-call basis to suppress the use of the preferred CUG, i.e. act as if the user is not a member of the closed user group, and to suppress the outgoing access permission, i.e. to insist that the call only go through if the destination is a member of the CUG.

When an incoming call is received it is possible for the network to indicate the closed user group that is being applied to the call to the called user.

For example:

Mr Smith, a senior member at a pizza delivery outlet, could be a member of two closed user groups:

* his own team of pizza delivery agents;
* his peer group of senior pizza delivery executives.

Mr Smith's preferred CUG would be that of his team. But based on whom Mr. Smith is calling, he can either suppress or enable the preferred CUG. Also, when Mr. Smith receives a call, the network would indicate which user group the call originated from.

As can be seen, this supplementary service is restricted in use only by organizations, and is not for use by the general public. However, there are handsets that support closed user group applications.

Details

A users' group (also user's group or user group) is a type of club focused on the use of a particular technology, usually (but not always) computer-related.

Overview

Users' groups started in the early days of mainframe computers, as a way to share sometimes hard-won knowledge and useful software, usually written by end users independently of the vendor-supplied programming efforts. SHARE, a user group originated by aerospace industry corporate users of IBM mainframe computers, was founded in 1955 and is the oldest computer user group still active. DECUS, the DEC User's Society, was founded in 1961 and its descendant organization, Connect Worldwide, still operates. The Computer Measurement Group (CMG) was founded in 1974 by systems professionals with a common interest in (mainframe) capacity management, and continues today with a much broader mission. The first UNIX users' group organized in 1978.

Users' groups began to proliferate with the microcomputer revolution of the late 1970s and early 1980s as hobbyists united to help each other with programming and configuration and use of hardware and software. Especially prior to the emergence of the World Wide Web, obtaining technical assistance with computers was often onerous, while computer clubs would gladly provide free technical support. Users' groups today continue to provide "real life" opportunities for learning from the shared experience of the members and may provide other functions such as a newsletter, group purchasing opportunities, tours of facilities, or speakers at group meetings.

A users' group may provide its members (and sometimes the general public as well) with one or more of the following services:

* periodic meetings
* annual or less frequent users conferences
* public lectures
* a newsletter
* a library of media or tools
* a software archive
* an online presence such as a dial-up BBS or Internet website
* swap meets
* technical support
* social events
* Code Camp

Users' groups may be organized around a particular brand of current hardware (e.g. IBM, Macintosh, AMD), or current software and operating systems (e.g. Linux, Microsoft Windows, macOS), or more rarely may be dedicated to obsolescent, retro systems or historical computers (e.g. Apple II, PDP-11, Osborne). An example of an early user group is the Apple User Group Connection.

Computer user group

A computer user group (also known as a computer club) is a group of people who enjoy using microcomputers or personal computers and who meet regularly to discuss the use of computers, share knowledge and experience, hear from representatives of hardware manufacturers and software publishers, and hold other related activities. They may host special interest workgroups, often focusing on one particular aspect of computing.

Computer user groups meet both virtually and in hackerspaces. Computer user groups may consist of members who primarily use a specific operating system, such as Linux. While many hackers use free and open source software, others use Macintosh, RISC OS, Windows and Amiga OS. There are also other user groups that concentrate on either Mac OS (Macintosh User Group or MUG) or Linux (Linux User Group or LUG).

Many computer user groups belong to an umbrella organization, the Association of Personal Computer User Groups or APCUG.

Additional Information

In personal or business computing, a user group is a set of people who have similar interests, goals or concerns. The members have regular meetings where they can share their ideas.

Ideally, the members of a user group live in the same geographic area, so they can get together in person. However, some user groups have members distributed throughout the world. So they meet using internet chat rooms, on social media and message boards, or mailing lists.

Members may also correspond by telephone and email on a one-to-one basis. User groups often have websites that each member can visit on a regular basis to stay informed.

Types of user groups

The term "user group" can be used to specify a few different scenarios:

* A social user group is often devoted to discussing and troubleshooting a particular technology or product.
* A special interest group (SIG) is a user group that is devoted to a narrow range of products or ideas.
* A software user group is a group of people who use a particular product or platform to discuss their experiences and gain support. For example, Oracle, IBM and the Android operating system all have user groups.

Managing a user group

While the functionality of a user group will differ based on the type of group being referenced, an administrator (sometimes referred to as an admin or system administrator) is needed to govern the group and manage users.

Some of the admin's common functions include:

* Establishing a group name for a new user group
* Maintaining a list of users or active group members and adding users
* Assigning roles and responsibilities to users
* Determining when and where a user group will meet (for social and SIG groups)
* Assigning certain users to subgroups (for software user groups)
* Maintaining group permission functionality (for software user groups)

For business, user groups enable a company's customers to interact and address issues about specific products and services together and with support staff. They enable companies to better understand their customers, partners and/or employees, and provide platforms where they can gain insights into customer satisfaction to improve the user experience and increase customer retention.

Jai Ganesh · 2024-07-28 00:50:49

2233) Global Positioning System

Gist

The global positioning system (GPS) is a network of satellites and receiving devices used to determine the location of something on Earth. Some GPS receivers are so accurate they can establish their location within one centimeter (0.4 inches). GPS receivers provide location in latitude, longitude, and altitude.

Summary

A global positioning system (GPS) is a network of satellites and receiving devices used to determine the location of something on Earth. Some GPS receivers are so accurate they can establish their location within 1 centimeter.

The global positioning system (GPS) is a network of satellites and receiving devices used to determine the location of something on Earth. Some GPS receivers are so accurate they can establish their location within one centimeter (0.4 inches). GPS receivers provide location in latitude, longitude, and altitude. They also provide the accurate time.

GPS includes 24 satellites that circle Earth in precise orbits. Each satellite makes a full orbit of Earth every 12 hours. These satellites are constantly sending out radio signals.

GPS receivers are programmed to receive information about where each satellite is at any given moment. A GPS receiver determines its own location by measuring the time it takes for a signal to arrive at its location from at least four satellites. Because radio waves travel at a constant speed, the receiver can use the time measurements to calculate its distance from each satellite.

Using multiple satellites makes the GPS data more accurate. If a GPS receiver calculates its distance from only one satellite, it could be that exact distance from the satellite in any direction. Think of the satellite as a flashlight. When you shine it on the ground, you get a circle of light. With one satellite, the GPS receiver could be anywhere in that circle of light. With two more satellites, there are two more circles. These three circles intersect, or cross, in only one place. That is the location of the GPS receiver. This method of determining location is called trilateration.

Aircraft, ships, submarines, trains, and the space shuttle all use GPS to navigate. Many people use receivers when driving cars. The GPS receiver plots the car's constantly-changing location on an electronic map. The map provides directions to the person's destination. Both the location and the vehicle are plotted using satellite data. Some hikers use GPS to help them find their way, especially when they are not on marked trails.

Sometimes there are obstacles to getting a clear GPS signal. Gravity can pull the GPS satellites slightly out of orbit. Parts of Earth's atmosphere sometimes distort the satellite radio signals. Trees, buildings, and other structures can also block the radio waves. GPS control and monitoring stations around the world track the satellites and constantly monitor their signals. They then calculate corrections that are broadcast to GPS receivers. These corrections make GPS much more accurate.

The original GPS system began as a project of the U.S. military. The first experimental satellite was launched in 1978. By 1994, a full 24 GPS satellites were orbiting Earth. At first, GPS available for civilian, or nonmilitary, use was not very accurate. It would only locate a GPS receiver within about 300 meters (1,000 feet). Today, an accurate signal is free and available to anyone with a GPS receiver.

GPS is American. Russia has its own version of a GPS system, called GLONASS (Global Orbiting Navigation Satellite System). China and the European Union are currently creating systems of their own.

Details

The Global Positioning System (GPS), originally Navstar GPS, is a satellite-based radio navigation system owned by the United States government and operated by the United States Space Force. It is one of the global navigation satellite systems (GNSS) that provide geolocation and time information to a GPS receiver anywhere on or near the Earth where there is an unobstructed line of sight to four or more GPS satellites. It does not require the user to transmit any data, and operates independently of any telephone or Internet reception, though these technologies can enhance the usefulness of the GPS positioning information. It provides critical positioning capabilities to military, civil, and commercial users around the world. Although the United States government created, controls and maintains the GPS system, it is freely accessible to anyone with a GPS receiver.

Overview

The GPS project was started by the U.S. Department of Defense in 1973. The first prototype spacecraft was launched in 1978 and the full constellation of 24 satellites became operational in 1993.

After Korean Air Lines Flight 007 was shot down when it mistakenly entered Soviet airspace, President Ronald Reagan announced that the GPS system would be made available for civilian use as of September 16, 1983; however, initially this civilian use was limited to an average accuracy of 100 meters (330 ft) by use of Selective Availability (SA), a deliberate error introduced into the GPS data (which military receivers could correct for).

As civilian GPS usage grew, there was increasing pressure to remove this error. The SA system was temporarily disabled during the Gulf War, as a shortage of military GPS units meant that many US soldiers were using civilian GPS units sent from home. In the 1990s, Differential GPS systems from the US Coast Guard, Federal Aviation Administration, and similar agencies in other countries began to broadcast local GPS corrections, reducing the effect of both SA degradation and atmospheric effects (that military receivers also corrected for). The US military had also developed methods to perform local GPS jamming, meaning that the ability to globally degrade the system was no longer necessary. As a result, President Bill Clinton signed a bill ordering that Selective Availability be disabled on May 1 2000; and, in 2007, the US government announced that the next generation of GPS satellites would not include the feature at all.

Advances in technology and new demands on the existing system have now led to efforts to modernize the GPS and implement the next generation of GPS Block III satellites and Next Generation Operational Control System (OCX) which was authorized by the U.S. Congress in 2000. When Selective Availability was discontinued, GPS was accurate to about 5 meters (16 ft). GPS receivers that use the L5 band have much higher accuracy of 30 centimeters (12 in), while those for high-end applications such as engineering and land surveying are accurate to within 2 cm (3⁄4 in) and can even provide sub-millimeter accuracy with long-term measurements. Consumer devices such as smartphones can be accurate to 4.9 m (16 ft) or better when used with assistive services like Wi-Fi positioning.

As of July 2023, 18 GPS satellites broadcast L5 signals, which are considered pre-operational prior to being broadcast by a full complement of 24 satellites in 2027.

Regulatory spectrum issues concerning GPS receivers

In the United States, GPS receivers are regulated under the Federal Communications Commission's (FCC) Part 15 rules. As indicated in the manuals of GPS-enabled devices sold in the United States, as a Part 15 device, it "must accept any interference received, including interference that may cause undesired operation". With respect to GPS devices in particular, the FCC states that GPS receiver manufacturers "must use receivers that reasonably discriminate against reception of signals outside their allocated spectrum". For the last 30 years, GPS receivers have operated next to the Mobile Satellite Service band, and have discriminated against reception of mobile satellite services, such as Inmarsat, without any issue.

The spectrum allocated for GPS L1 use by the FCC is 1559 to 1610 MHz, while the spectrum allocated for satellite-to-ground use owned by Lightsquared is the Mobile Satellite Service band. Since 1996, the FCC has authorized licensed use of the spectrum neighboring the GPS band of 1525 to 1559 MHz to the Virginia company LightSquared. On March 1, 2001, the FCC received an application from LightSquared's predecessor, Motient Services, to use their allocated frequencies for an integrated satellite-terrestrial service.[193] In 2002, the U.S. GPS Industry Council came to an out-of-band-emissions (OOBE) agreement with LightSquared to prevent transmissions from LightSquared's ground-based stations from emitting transmissions into the neighboring GPS band of 1559 to 1610 MHz. In 2004, the FCC adopted the OOBE agreement in its authorization for LightSquared to deploy a ground-based network ancillary to their satellite system – known as the Ancillary Tower Components (ATCs) – "We will authorize MSS ATC subject to conditions that ensure that the added terrestrial component remains ancillary to the principal MSS offering. We do not intend, nor will we permit, the terrestrial component to become a stand-alone service." This authorization was reviewed and approved by the U.S. Interdepartment Radio Advisory Committee, which includes the U.S. Department of Agriculture, U.S. Space Force, U.S. Army, U.S. Coast Guard, Federal Aviation Administration, National Aeronautics and Space Administration (NASA), U.S. Department of the Interior, and U.S. Department of Transportation.

In January 2011, the FCC conditionally authorized LightSquared's wholesale customers—such as Best Buy, Sharp, and C Spire—to only purchase an integrated satellite-ground-based service from LightSquared and re-sell that integrated service on devices that are equipped to only use the ground-based signal using LightSquared's allocated frequencies of 1525 to 1559 MHz. In December 2010, GPS receiver manufacturers expressed concerns to the FCC that LightSquared's signal would interfere with GPS receiver devices although the FCC's policy considerations leading up to the January 2011 order did not pertain to any proposed changes to the maximum number of ground-based LightSquared stations or the maximum power at which these stations could operate. The January 2011 order makes final authorization contingent upon studies of GPS interference issues carried out by a LightSquared led working group along with GPS industry and Federal agency participation. On February 14, 2012, the FCC initiated proceedings to vacate LightSquared's Conditional Waiver Order based on the NTIA's conclusion that there was currently no practical way to mitigate potential GPS interference.

GPS receiver manufacturers design GPS receivers to use spectrum beyond the GPS-allocated band. In some cases, GPS receivers are designed to use up to 400 MHz of spectrum in either direction of the L1 frequency of 1575.42 MHz, because mobile satellite services in those regions are broadcasting from space to ground, and at power levels commensurate with mobile satellite services. As regulated under the FCC's Part 15 rules, GPS receivers are not warranted protection from signals outside GPS-allocated spectrum. This is why GPS operates next to the Mobile Satellite Service band, and also why the Mobile Satellite Service band operates next to GPS. The symbiotic relationship of spectrum allocation ensures that users of both bands are able to operate cooperatively and freely.

The FCC adopted rules in February 2003 that allowed Mobile Satellite Service (MSS) licensees such as LightSquared to construct a small number of ancillary ground-based towers in their licensed spectrum to "promote more efficient use of terrestrial wireless spectrum". In those 2003 rules, the FCC stated: "As a preliminary matter, terrestrial [Commercial Mobile Radio Service ('CMRS')] and MSS ATC are expected to have different prices, coverage, product acceptance and distribution; therefore, the two services appear, at best, to be imperfect substitutes for one another that would be operating in predominantly different market segments ... MSS ATC is unlikely to compete directly with terrestrial CMRS for the same customer base...". In 2004, the FCC clarified that the ground-based towers would be ancillary, noting: "We will authorize MSS ATC subject to conditions that ensure that the added terrestrial component remains ancillary to the principal MSS offering. We do not intend, nor will we permit, the terrestrial component to become a stand-alone service." In July 2010, the FCC stated that it expected LightSquared to use its authority to offer an integrated satellite-terrestrial service to "provide mobile broadband services similar to those provided by terrestrial mobile providers and enhance competition in the mobile broadband sector". GPS receiver manufacturers have argued that LightSquared's licensed spectrum of 1525 to 1559 MHz was never envisioned as being used for high-speed wireless broadband based on the 2003 and 2004 FCC ATC rulings making clear that the Ancillary Tower Component (ATC) would be, in fact, ancillary to the primary satellite component. To build public support of efforts to continue the 2004 FCC authorization of LightSquared's ancillary terrestrial component vs. a simple ground-based LTE service in the Mobile Satellite Service band, GPS receiver manufacturer Trimble Navigation Ltd. formed the "Coalition To Save Our GPS".

The FCC and LightSquared have each made public commitments to solve the GPS interference issue before the network is allowed to operate. According to Chris Dancy of the Aircraft Owners and Pilots Association, airline pilots with the type of systems that would be affected "may go off course and not even realize it". The problems could also affect the Federal Aviation Administration upgrade to the air traffic control system, United States Defense Department guidance, and local emergency services including 911.

On February 14, 2012, the FCC moved to bar LightSquared's planned national broadband network after being informed by the National Telecommunications and Information Administration (NTIA), the federal agency that coordinates spectrum uses for the military and other federal government entities, that "there is no practical way to mitigate potential interference at this time". LightSquared is challenging the FCC's action.

Additional Information

GPS, space-based radio-navigation system that broadcasts highly accurate navigation pulses to users on or near Earth. In the United States’ Navstar GPS, 24 main satellites in 6 orbits circle Earth every 12 hours. In addition, Russia maintains a constellation called GLONASS (Global Navigation Satellite System), and in 2007 the European Union approved financing for the launch of 30 satellites to form its own version of GPS, known as Galileo, which began operations in 2016. China launched two satellites in 2000 and another in 2003 as part of a local navigation system first known as BeiDou (“Big Dipper”). In 2006 China, which had a limited participation in Galileo, announced plans to expand BeiDou to a full GPS service known as the BeiDou Navigation System. In 2007 China began launching a series of 14 second-generation satellites, known as BeiDou-2, or Compass, to provide services in China. A third-generation constellation of 30 satellites, BeiDou-3, was completed in 2020 and provides global service.

A GPS receiver operated by a user on Earth measures the time it takes radio signals to travel from four or more satellites to its location, calculates the distance to each satellite, and from this calculation determines the user’s longitude, latitude, and altitude. The U.S. Department of Defense originally developed the Navstar constellation for military use, but a less precise form of the service is available free of charge to civilian users around the globe. The basic civilian service will locate a receiver within 10 metres (33 feet) of its true location, though various augmentation techniques can be used to pinpoint the location within less than 1 cm (0.4 inch). With such accuracy and the ubiquity of the service, GPS has evolved far beyond its original military purpose and has created a revolution in personal and commercial navigation. Battlefield missiles and artillery projectiles use GPS signals to determine their positions and velocities, but so do the U.S. space shuttle and the International Space Station as well as commercial jetliners and private airplanes. Ambulance fleets, family automobiles, and railroad locomotives benefit from GPS positioning, which also serves farm tractors, ocean liners, hikers, and even golfers. Many GPS receivers are no larger than a pocket calculator and are powered by disposable batteries, while GPS computer chips the size of a baby’s fingernail have been installed in wristwatches, cellular telephones, and personal digital assistants.

Triangulation

The principle behind the unprecedented navigational capabilities of GPS is triangulation. To triangulate, a GPS receiver precisely measures the time it takes for a satellite signal to make its brief journey to Earth—less than a tenth of a second. Then it multiplies that time by the speed of a radio wave—300,000 km (186,000 miles) per second—to obtain the corresponding distance between it and the satellite. This puts the receiver somewhere on the surface of an imaginary sphere with a radius equal to its distance from the satellite. When signals from three other satellites are similarly processed, the receiver’s built-in computer calculates the point at which all four spheres intersect, effectively determining the user’s current longitude, latitude, and altitude. (In theory, three satellites would normally provide an unambiguous three-dimensional fix, but in practice at least four are used to offset inaccuracy in the receiver’s clock.) In addition, the receiver calculates current velocity (speed and direction) by measuring the instantaneous Doppler effect shifts created by the combined motion of the same four satellites.

In the Navstar system, each satellite broadcasts its navigation signals on two frequencies—1575.42 megahertz (military/civilian) and 1227.6 megahertz (military). These carrier waves are modulated by two pseudo-random binary pulse trains: a 1-megabit-per-second civilian C/A-code (coarse acquisition code) and a 10-megabit-per-second military P-code (precision code). Three new civilian signals are planned at 1176.45, 1227.6, and 1575.42 MHz. Until 2000, a feature known as selective availability (S/A) intentionally degraded the civilian signal’s accuracy; S/A was terminated in part because of safety concerns related to the increasing use of GPS by civilian marine vessels and aircraft. Unaugmented civilian GPS now gives an error variance, for horizontal distances, of 30 metres (100 feet) with a probability of 95 percent—that is, 95 percent of the time the reported location is within 30 metres of the true location. Typical horizontal accuracy is about 10 metres (30 feet; compared with 100 metres [330 feet] with S/A), while vertical accuracy, or altitude, is approximately half as precise. The Doppler effect allows receivers to determine a user’s velocity to an accuracy of about 1 metre (3 feet) per second. The unaugmented military signal, meanwhile, has a horizontal error variance of less than 3 metres (10 feet).

Augmentation

Although the travel time of a satellite signal to Earth is only a fraction of a second, much can happen to it in that interval. For example, electrically charged particles in the ionosphere and density variations in the troposphere may act to slow and distort satellite signals. These influences can translate into positional errors for GPS users—a problem that can be compounded by timing errors in GPS receiver clocks. Further errors may be introduced by relativistic time dilations, a phenomenon in which a satellite’s clock and a receiver’s clock, located in different gravitational fields and traveling at different velocities, tick at different rates. Finally, the single greatest source of error to users of the Navstar system is the lower accuracy of the civilian C/A-code pulse. However, various augmentation methods exist for improving the accuracy of both the military and the civilian systems.

When positional information is required with pinpoint precision, users can take advantage of differential GPS techniques. Differential navigation employs a stationary “base station” that sits at a known position on the ground and continuously monitors the signals being broadcast by GPS satellites in its view. It then computes and broadcasts real-time navigation corrections to nearby roving receivers. Each roving receiver, in effect, subtracts its position solution from the base station’s solution, thus eliminating any statistical errors common to the two. The U.S. Coast Guard maintains a network of such base stations and transmits corrections over radio beacons covering most of the United States. Other differential corrections are encoded within the normal broadcasts of commercial radio stations. Farmers receiving these broadcasts have been able to direct their field equipment with great accuracy, making precision farming a common term in agriculture.

Another GPS augmentation technique uses the carrier waves that convey the satellites’ navigation pulses to Earth. Because the length of the carrier wave is more than 1,000 times shorter than the basic navigation pulses, this “carrier-aided” approach, under the right circumstances, can reduce navigation errors to less than 1 cm (0.4 inch). The dramatically improved accuracy stems primarily from the shorter length and much greater numbers of carrier waves impinging on the receiver’s antenna each second.

Yet another augmentation technique is known as geosynchronous overlays. Geosynchronous overlays employ GPS payloads “piggybacked” aboard commercial communication satellites that are placed in geostationary orbit some 35,000 km (22,000 miles) above Earth. These relatively small payloads broadcast civilian C/A-code pulse trains to ground-based users. The U.S. government is enlarging the Navstar constellation with geosynchronous overlays to achieve improved coverage, accuracy, and survivability. Both the European Union and Japan are installing their own geosynchronous overlays.

The Navstar system

The Navstar GPS system consists of three major segments: the space segment, the control segment, and the user segment. The space component is made up of the Navstar constellation in orbit around Earth. The first satellite was an experimental Block I model launched in 1978. Nine more of these developmental satellites followed over the next decade, and 23 heavier and more-capable Block II production models were sent into space from 1989 to 1993. The launch of the 24th Block II satellite in 1994 completed the GPS constellation, which now consists of two dozen Block II satellites (plus three spares orbiting in reserve) marching in single file in six circular orbits around Earth. The orbits are arranged so that at least five satellites are in view from most points on Earth at all times. Since 1994, newer versions of Block II satellites have been launched to replace older models. The first satellite of Block III was launched in 2018. Ten Block III satellites were planned with the final launch scheduled for 2023.

A typical Block II satellite weighs approximately 900 kg (2,000 pounds) and, with its solar panels extended, is about 17 metres (56 feet) across. Its key elements are the winglike solar arrays that generate electrical power from sunlight, the 12 helical antennas that transmit navigation pulses to users on the ground, and its long, spearlike radio antenna that picks up instructions from control engineers. As a satellite coasts through its 12-hour orbit, its main body pivots continuously and the solar arrays swivel, keeping its navigation antennas pointing toward Earth’s centre and its solar arrays aligned perpendicular to the Sun’s rays.

The control segment consists of one Master Control Station at a U.S. Air Force base in Colorado and four additional uncrewed monitoring stations positioned around the world—Hawaii and Kwajalein Atoll in the Pacific Ocean, Diego Garcia in the Indian Ocean, and Ascension Island in the Atlantic Ocean. Each monitoring station tracks all of the GPS satellites in its view to check for orbital changes. Variations in satellite orbits are caused by gravitational pulls from the Moon and Sun, the nonspherical shape of Earth, and the pressure of solar radiation. This information is processed at the Master Control Station, and corrected orbital information is quickly relayed back to the satellites via large ground antennas. Every 18 months on average, the satellites within a given ring drift too far from their original configuration and must be nudged back with onboard thrusters fired by ground control.

The user segment consists of the millions of GPS receivers that pick up and decode the satellite signals. Hundreds of different types of GPS receivers are in use; some are designed for installation in automobiles, trucks, submarines, ships, aircraft, and orbiting satellites, whereas smaller models have been developed for personal navigation.

Jai Ganesh · 2024-07-28 20:08:08

2234) Wood

Wood

Gist

Wood is a structural tissue found in the stems and roots of trees and other woody plants. It is an organic material – a natural composite of cellulose fibers that are strong in tension and embedded in a matrix of lignin that resists compression.

Summary

Wood, the principal strengthening and nutrient-conducting tissue of trees and other plants and one of the most abundant and versatile natural materials. Produced by many botanical species, including both gymnosperms and angiosperms, wood is available in various colours and grain patterns. It is strong in relation to its weight, is insulating to heat and electricity, and has desirable acoustic properties. Furthermore, it imparts a feeling of “warmth” not possessed by competing materials such as metals or stone, and it is relatively easily worked. As a material, wood has been in service since humans appeared on Earth. Today, in spite of technological advancement and competition from metals, plastics, cement, and other materials, wood maintains a place in most of its traditional roles, and its serviceability is expanding through new uses. In addition to well-known products such as lumber, furniture, and plywood, wood is the raw material for wood-based panels, pulp and paper, and many chemical products. Finally, wood is still an important fuel in much of the world.

Production and consumption of wood

In botanical terms, wood is part of the system that conveys water and dissolved minerals from the roots to the rest of the plant, stores food created by photosynthesis, and furnishes mechanical support. It is produced by an estimated 25,000 to 30,000 species of plants, including herbaceous ones, though only 3,000 to 4,000 species produce wood that is suitable for use as a material. Wood-producing forest trees and other woody plants are of two categories: gymnosperms and angiosperms. Gymnosperms, or cone-bearing trees, produce softwoods, such as pine and spruce, and angiosperms produce temperate and tropical hardwoods, such as oak, beech, teak, and balsa. It should be noted that the distinction implied by hardwood and softwood is not true in all cases. Some hardwoods—e.g., balsa—are softer than some softwoods—e.g., yew.

Wood is a material of great economic importance. It is found throughout the world and can be sustainably managed as a renewable resource—in contrast to coal, ores, and petroleum, which are gradually exhausted. By means of its harvesting in forests, its transportation, its processing in workshops and industries, and its trade and use, wood provides jobs and supports economic development and, in some countries, basic subsistence. Indicative of this importance is the continued high demand for wood and wood products.

On a weight basis, the consumption of wood exceeds by far that of other materials. More than half of roundwood (log) production is consumed as fuel, mainly in less-developed countries. Production of paper and paperboard has shown the most rapid increase among wood products; this trend is expected to continue as consumption per person in the less-developed countries approaches that in the developed nations. Rising world population is the driving force of increasing consumption of wood and consequent deforestation. The depletion of many forests, especially in the tropics, makes uncertain the provision of an adequate wood supply to satisfy the anticipated need. Efforts to stop the reduction of Earth’s forest cover and increase the productivity of existing forests, establishment of extensive reforestation programs and plantations of fast-growing tree species, recycling of paper, and improved utilization of wood through research could ease the problem of wood supply and help to lessen the environmental toll of the lumber industry.

Details

Wood is a structural tissue found in the stems and roots of trees and other woody plants. It is an organic material – a natural composite of cellulose fibers that are strong in tension and embedded in a matrix of lignin that resists compression. Wood is sometimes defined as only the secondary xylem in the stems of trees, or more broadly to include the same type of tissue elsewhere, such as in the roots of trees or shrubs. In a living tree it performs a support function, enabling woody plants to grow large or to stand up by themselves. It also conveys water and nutrients between the leaves, other growing tissues, and the roots. Wood may also refer to other plant materials with comparable properties, and to material engineered from wood, woodchips, or fiber.

Wood has been used for thousands of years for fuel, as a construction material, for making tools and weapons, furniture and paper. More recently it emerged as a feedstock for the production of purified cellulose and its derivatives, such as cellophane and cellulose acetate.

As of 2020, the growing stock of forests worldwide was about 557 billion cubic meters. As an abundant, carbon-neutral renewable resource, woody materials have been of intense interest as a source of renewable energy. In 2008, approximately 3.97 billion cubic meters of wood were harvested. Dominant uses were for furniture and building construction.

Wood is scientifically studied and researched through the discipline of wood science, which was initiated since the beginning of the 20th century.

History

A 2011 discovery in the Canadian province of New Brunswick yielded the earliest known plants to have grown wood, approximately 395 to 400 million years ago.

Wood can be dated by carbon dating and in some species by dendrochronology to determine when a wooden object was created.

People have used wood for thousands of years for many purposes, including as a fuel or as a construction material for making houses, tools, weapons, furniture, packaging, artworks, and paper. Known constructions using wood date back ten thousand years. Buildings like the longhouses in Neolithic Europe were made primarily of wood.

Recent use of wood has been enhanced by the addition of steel and bronze into construction.

The year-to-year variation in tree-ring widths and isotopic abundances gives clues to the prevailing climate at the time a tree was cut.

Uses:

Production

Global production of roundwood rose from 3.5 billion m³ in 2000 to 4 billion m³ in 2021. In 2021, wood fuel was the main product with a 49 percent share of the total (2 billion m³), followed by coniferous industrial roundwood with 30 percent (1.2 billion m³) and non-coniferous industrial roundwood with 21 percent (0.9 billion m³). Asia and the Americas are the two main producing regions, accounting for 29 and 28 percent of the total roundwood production, respectively; Africa and Europe have similar shares of 20–21 percent, while Oceania produces the remaining 2 percent.

Fuel

Wood has a long history of being used as fuel, which continues to this day, mostly in rural areas of the world. Hardwood is preferred over softwood because it creates less smoke and burns longer. Adding a woodstove or fireplace to a home is often felt to add ambiance and warmth.

Pulpwood

Pulpwood is wood that is raised specifically for use in making paper.

Construction

Wood has been an important construction material since humans began building shelters, houses and boats. Nearly all boats were made out of wood until the late 19th century, and wood remains in common use today in boat construction. Elm in particular was used for this purpose as it resisted decay as long as it was kept wet (it also served for water pipe before the advent of more modern plumbing).

Wood to be used for construction work is commonly known as lumber in North America. Elsewhere, lumber usually refers to felled trees, and the word for sawn planks ready for use is timber. In Medieval Europe oak was the wood of choice for all wood construction, including beams, walls, doors, and floors. Today a wider variety of woods is used: solid wood doors are often made from poplar, small-knotted pine, and Douglas fir.

New domestic housing in many parts of the world today is commonly made from timber-framed construction. Engineered wood products are becoming a bigger part of the construction industry. They may be used in both residential and commercial buildings as structural and aesthetic materials.

In buildings made of other materials, wood will still be found as a supporting material, especially in roof construction, in interior doors and their frames, and as exterior cladding.

Wood is also commonly used as shuttering material to form the mold into which concrete is poured during reinforced concrete construction.

Flooring

A solid wood floor is a floor laid with planks or battens created from a single piece of timber, usually a hardwood. Since wood is hydroscopic (it acquires and loses moisture from the ambient conditions around it) this potential instability effectively limits the length and width of the boards.

Solid hardwood flooring is usually cheaper than engineered timbers and damaged areas can be sanded down and refinished repeatedly, the number of times being limited only by the thickness of wood above the tongue.

Solid hardwood floors were originally used for structural purposes, being installed perpendicular to the wooden support beams of a building (the joists or bearers) and solid construction timber is still often used for sports floors as well as most traditional wood blocks, mosaics and parquetry.

Engineered products

Engineered wood products, glued building products "engineered" for application-specific performance requirements, are often used in construction and industrial applications. Glued engineered wood products are manufactured by bonding together wood strands, veneers, lumber or other forms of wood fiber with glue to form a larger, more efficient composite structural unit.

These products include glued laminated timber (glulam), wood structural panels (including plywood, oriented strand board and composite panels), laminated veneer lumber (LVL) and other structural composite lumber (SCL) products, parallel strand lumber, and I-joists. Approximately 100 million cubic meters of wood was consumed for this purpose in 1991. The trends suggest that particle board and fiber board will overtake plywood.

Wood unsuitable for construction in its native form may be broken down mechanically (into fibers or chips) or chemically (into cellulose) and used as a raw material for other building materials, such as engineered wood, as well as chipboard, hardboard, and medium-density fiberboard (MDF). Such wood derivatives are widely used: wood fibers are an important component of most paper, and cellulose is used as a component of some synthetic materials. Wood derivatives can be used for kinds of flooring, for example laminate flooring.

Furniture and utensils

Wood has always been used extensively for furniture, such as chairs and beds. It is also used for tool handles and cutlery, such as chopsticks, toothpicks, and other utensils, like the wooden spoon and pencil.

Other

Further developments include new lignin glue applications, recyclable food packaging, rubber tire replacement applications, anti-bacterial medical agents, and high strength fabrics or composites. As scientists and engineers further learn and develop new techniques to extract various components from wood, or alternatively to modify wood, for example by adding components to wood, new more advanced products will appear on the marketplace. Moisture content electronic monitoring can also enhance next generation wood protection.

Art

Wood has long been used as an artistic medium. It has been used to make sculptures and carvings for millennia. Examples include the totem poles carved by North American indigenous people from conifer trunks, often Western Red Cedar (Thuja plicata).

Other uses of wood in the arts include:

* Woodcut printmaking and engraving
* Wood can be a surface to paint on, such as in panel painting
* Many musical instruments are made mostly or entirely of wood

Sports and recreational equipment

Many types of sports equipment are made of wood, or were constructed of wood in the past. For example, cricket bats are typically made of white willow. The baseball bats which are legal for use in Major League Baseball are frequently made of ash wood or hickory, and in recent years have been constructed from maple even though that wood is somewhat more fragile. National Basketball Association courts have been traditionally made out of parquetry.

Many other types of sports and recreation equipment, such as skis, ice hockey sticks, lacrosse sticks and archery bows, were commonly made of wood in the past, but have since been replaced with more modern materials such as aluminium, titanium or composite materials such as fiberglass and carbon fiber. One noteworthy example of this trend is the family of golf clubs commonly known as the woods, the heads of which were traditionally made of persimmon wood in the early days of the game of golf, but are now generally made of metal or (especially in the case of drivers) carbon-fiber composites.

Additional Information

Wood is the main substance in trees. It is mainly formed by the xylem vessels which carry water up the plant. The two main substances in wood are cellulose and lignin. Wood is used to make buildings and furniture, and also for art. Firewood is a fuel. Paper is made from wood fibres. Wood is a renewable resource although it has become scarcer in recent centuries. Its origin is about 425 million years ago.

Wood is hard to cut, but it is also strong. A lumberjack is a person who cuts down trees. After a tree falls, the wood in it can be cut into long, straight pieces called lumber. Lumber can then be used to make posts, or put together with nails, screws, or even glue to make wooden frames for other shapes.

Wood comes in many different kinds. Oak, maple (hardwood) and pine and redwood (softwood) are widely used types of wood. Woods are usually divided into softwood (from conifers) and hardwood from flowering plants.

Housing

For a long time and even today, many buildings, mostly houses, have been made of wood. To build a house with wood, lumber is put together into frames that are the shape of each wall, floor, and roof of the house. Then the frames are placed into the shape of a house. Then the frames can be covered to make solid walls. Sometimes the walls are made of more wood.

When the outside of a house or building is covered in wood, the wooden pieces are usually flat and stacked. These pieces are called shingles. Wood is also sometimes used in other parts of the house, like doors and staircases. Wood is also used to make fences.

Carpentry

Carpenters make houses of mostly soft wood such as pine. For many kinds of furniture they use harder wood such as maple or oak. When someone builds something with wood, they often paint it. Paint protects and beautifies the wood. Some people like the look of wood, so they put clear paint called varnish on it. This helps to protect the wood and gives it a shiny finish.

Some people make art with wood. Sometimes sculptures are built with wood: see Grinling Gibbons.

Regular pencils are made of wood. Inside is the "lead", which is not actually lead. Clay or wax and graphite form the "lead" in a pencil.

Paper

Wood is turned into paper in large factories called paper mills. Heat, chemicals and machines separate the cellulose fibers from other parts and press the fibers into paper.

oak-wooden-bar-blocks-stacked-at-carpentry-woodwork-workshop-with-tools_Gorlov-KV_Shutterstock.webp

Jai Ganesh · 2024-07-29 13:32:09

2235) Kiwifruit

Details

Kiwifruit (often shortened to kiwi outside New Zealand and Australia) or Chinese gooseberry, is the edible berry of several species of woody vines in the genus Actinidia. The most common cultivar group of kiwifruit (Actinidia deliciosa 'Hayward') is oval, about the size of a large hen's egg: 5–8 centimetres (2–3 inches) in length and 4.5–5.5 cm (1+3⁄4–2+1⁄4 in) in diameter. Kiwifruit has a thin, fuzzy, fibrous, tart but edible light brown skin and light green or golden flesh with rows of tiny, black, edible seeds. The fruit has a soft texture with a sweet and unique flavour.

Kiwifruit is native to central and eastern China. The first recorded description of the kiwifruit dates to the 12th century during the Song dynasty. In the early 20th century, cultivation of kiwifruit spread from China to New Zealand, where the first commercial plantings occurred. The fruit became popular with British and American servicemen stationed in New Zealand during World War II, and later became commonly exported, first to Great Britain and then to California in the 1960s.

Etymology

Early varieties discovered and cultivated in China, were described in a 1904 nursery catalogue as having "...edible fruits the size of walnuts, and the flavour of ripe gooseberries", leading to the name Chinese gooseberry. In 1962, New Zealand growers began calling it "kiwifruit" (Māori: huakiwi) due to its fuzzy appearance similar to a kiwi for export marketing, and the name was first registered by Turners & Growers on 15 June 1959 and later commercially adopted in 1974. In New Zealand and Australia, the word kiwi alone either refers solely to the bird or is used as a nickname for New Zealanders; it is almost never used to refer to the fruit. Kiwifruit has since become a common name for all commercially grown green kiwifruit from the genus Actinidia. In the United States and Canada, the shortened name kiwi is commonly used when referring to the fruit.

History

Kiwifruit is native to central and eastern China. The first recorded description of the kiwifruit dates to 12th century China during the Song dynasty. As it was usually collected from the wild and consumed for medicinal purposes, the plant was rarely cultivated or bred. Cultivation of kiwifruit spread from China in the early 20th century to New Zealand, where the first commercial plantings occurred. The fruit became popular with British and American servicemen stationed in New Zealand during World War II and was later exported, first to Great Britain and then to California in the 1960s.

In New Zealand during the 1940s and 1950s, the fruit became an agricultural commodity through the development of commercially viable cultivars, agricultural practices, shipping, storage, and marketing.

Species and cultivars

The genus Actinidia comprises around 60 species. Their fruits are quite variable, although most are easily recognised as kiwifruit because of their appearance and shape. The skin of the fruit varies in size, hairiness and colour. The flesh varies in colour, juiciness, texture and taste. Some fruits are unpalatable, while others taste considerably better than the majority of commercial cultivars.

The most commonly sold kiwifruit is derived from A. deliciosa (fuzzy kiwifruit). Other species that are commonly eaten include A. chinensis (golden kiwifruit), A. coriacea (Chinese egg gooseberry), A. arguta (hardy kiwifruit), A. kolomikta (Arctic kiwifruit), A. melanandra (purple kiwifruit), A. polygama (silver vine) and A. purpurea (hearty red kiwifruit).

Fuzzy kiwifruit

Most kiwifruit sold belongs to a few cultivars of A. deliciosa (fuzzy kiwifruit): 'Hayward', 'Blake' and 'Saanichton 12'. They have a fuzzy, dull brown skin and bright green flesh. The familiar cultivar 'Hayward' was developed by Hayward Wright in Avondale, New Zealand, around 1924. It was initially grown in domestic gardens, but commercial planting began in the 1940s.

'Hayward' is the most commonly available cultivar in stores. It is a large, egg-shaped fruit with a sweet flavour. 'Saanichton 12', from British Columbia, is somewhat more rectangular than 'Hayward' and comparably sweet, but the inner core of the fruit can be tough. 'Blake' can self-pollinate, but it has a smaller, more oval fruit and the flavour is considered inferior.

Kiwi berries

Kiwi berries are edible fruits the size of a large grape, similar to fuzzy kiwifruit in taste and internal appearance but with a thin, smooth green skin. They are primarily produced by three species: Actinidia arguta (hardy kiwi), A. kolomikta (Arctic kiwifruit) and A. polygama (silver vine). They are fast-growing, climbing vines, durable over their growing season. They are referred to as "kiwi berry, baby kiwi, dessert kiwi, or grape kiwi.

The cultivar 'Issai' is a hybrid of hardy kiwi and silver vine which can self-pollinate. Grown commercially because of its relatively large fruit, 'Issai' is less hardy than most hardy kiwi.

Actinidia chinensis

Actinidia chinensis (yellow kiwi or golden kiwifruit) has a smooth, bronze skin, with a beak shape at the stem attachment. Flesh colour varies from bright green to a clear, intense yellow. This species is 'sweeter and more aromatic' in flavour compared to A. deliciosa. One of the most attractive varieties has a red 'iris' around the centre of the fruit and yellow flesh outside. The yellow fruit obtains a higher market price and, being less hairy than the fuzzy kiwifruit, is more palatable for consumption without peeling.

A commercially viable variety of this red-ringed kiwifruit, patented as EnzaRed, is a cultivar of the Chinese hong yang variety.

'Hort16A' is a golden kiwifruit cultivar marketed worldwide as Zespri Gold. This cultivar suffered significant losses in New Zealand in 2010–2013 due to the PSA bacterium. A new cultivar of golden kiwifruit, Gold3, was found to be more disease-resistant and most growers have now changed to this cultivar. 'Gold3', marketed by Zespri as SunGold is not quite as sweet as 'Hort16A', and lacks its usually slightly pointed tip.

Clones of the new variety SunGold have been used to develop orchards in China, resulting in partially successful legal efforts in China by Zespri to protect their intellectual property. In 2021, Zespri estimated that around 5,000 hectares of Sungold orchards were being cultivated in China, mainly in the Sichuan province.

Additional Information

Kiwifruit (Actinidia deliciosa) is a fruit. It has an oval shape. It is green on the inside with small black seeds that can be eaten. The kiwi has thin, fuzzy brown skin that is edible, but is usually removed. It natively grows in South China.

The fruit was named in 1959 after the kiwi, a bird and the symbol of New Zealand. Before that, its English name was Chinese gooseberry.

The kiwifruit is healthy and contains many vitamins and minerals. Kiwis are rich in vitamin C, vitamin K, potassium, and fiber. Kiwis have more vitamin C than an equivalent amount of orange.

There are different types of kiwifruit. The main types are Hayward (the most common green kiwifruit), chico, Saanichton 12, and golden kiwifruit. Golden kiwifruit are sweeter than normal green kiwifruit. Golden kiwifruit was invented by grafting and cross-pollinating different types of kiwifruit.

Kiwi fruit is the edible berry of a woody vine which can reach 18 to 24 feet in length. Kiwi Fruit can grow 3.1 inches in length and 2.2 inches in diameter, they have a soft texture, sweet Flavor, and their skin is covered in short stiff brown hairs.

The top 3 producers of kiwi fruit are Italy, New Zealand, and Chile. One medium-sized Kiwi without the skin provides 46 calories, 0.4 grams of fat, 11 grams of carbohydrate, 0.9 grams of protein, 2.3 grams of fiber, and 6.8 Grams of sugar.

Kiwi fruit are high in vitamin C and contain a good amount of vitamin K. Since Kiwi is so high in vitamin C it's an excellent source of antioxidants, which fight free radicals in the Body, it also provides nutrients that protect DNA in the nucleus of cells from oxygen damage.

Kiwi can also help fight against blood clots since it contains vitamin K. It can also help maintain beautiful skin, improve digestion, and help the body's immune system. Kiwi is also a cheap and healthy snack, one medium fruit usually costs around 89 cents. Consuming 2 kiwi fruit daily would meet and surpass the minimum daily vitamin C recommendation.

Kiwi was named after its resemblance to the fuzzy brown Kiwi, New Zealand's national bird. Kiwi is often used in DIY face masks because of its contents that fight the aging process.

Health Benefits Of Kiwi

1. Reduces asthma symptoms a rich source of vitamin c and antioxidants it improves lung function and a regular intake of the fruit is believed to bring down asthma symptoms.

2. Improves immunity for those suffering from low immunity this fruit is a must-have it fights microbes brings down seasonal infections and has anti-fungal properties.

3. Controls diabetes it not just is a low glycemic index but is also said to have properties that prevent the dysfunction of adipose tissue which has been linked with diabetes.

Jai Ganesh · 2024-07-30 13:39:07

2236) Limeade

Details

Limeade, also called lime soda, is a lime-flavored, sometimes carbonated, drink. It is usually sweetened with sugar or sweeteners. A common method of preparation is to juice limes and combine the juice with simple syrup or honey syrup, along with some water and perhaps more sugar or honey. Vodka or white tequila can be added to make a limeade. The exact ingredients, preparation and names of the drink can vary by country.

Most major beverage companies now offer their own brand of limeade, such as A.G. Barr of Glasgow and Newman's Own since 2004, with Minute Maid introducing a cherry limeade drink in response to the popularity of limeade.

Sonic Drive-In uses Sprite to create its popular cherry limeade.

Limeade is popular in tropical countries such as Jamaica where limes are common.

It is one of the most popular drinks in India and Pakistan and is known as nimbu paani or limbu pani; lemons can also be used for nimbu paani.

Limeade with ice, Thailand

Limeade is also widely available in Thailand and other parts of Southeast Asia due to the abundance of limes and relative rarity of lemons, as lemons are not a native species. A Thai-styled limeade tastes salty, and sometimes does not have any sugar.

Additional Information

One of the most refreshing drinks around, homemade limeade is tart yet sweet and marvelously thirst quenching. All you need to make it are fresh limes and sugar or honey—and water. It's a magical two-ingredient recipe (as are many lemonade recipes.) Mix it and chill for an hour to let the flavors mingle. Then serve over ice with lime slices and enjoy a drink that will help you beat the summer heat.

Our limeade recipe comes from former executive director of food and entertaining, Lucinda Scala Quinn, who came to love limeade during her time in Jamaica. The recipe appears in her book Lucinda's Authentic Jamaican Kitchen.

The Best Tool for Juicing Limes

The best tool for juicing a lime is the one you have in your kitchen. Since this is such a simple recipe, there's no reason to complicate it by calling for special equipment. But if you don't already own a tool for juicing citrus, we recommend a citrus reamer. It's a small wooden utensil that beats fancier, pricier options at getting the most juice from any kind of citrus—and you want to get all the lime juice you can when you're making limeade (don't let any go to waste).

A citrus reamer is a handheld juicer shaped like an inverted cone with a broad, blunt handle at the base. The cone has a ridged surface designed to get the greatest amount of juice from halved citrus fruits.

How to Store Limeade

This homemade limeade should stay fresh for five to seven days in the refrigerator so you can enjoy a glass every day for up to a week—if it lasts that long.

Frequently Asked Questions:

Which is better: fresh lime juice or bottled?

We always freshly squeezed lime juice over bottled. It doesn't take long to squeeze the limes for this limeade, so we suggest that is what you do. Some brands of bottled lime juice are better than others, but their flavor is not as bright and citrusy as fresh juice—and they contain preservatives.

How many limes make 1 cup of lime juice?

On average, a lime yields 2 tablespoons of fresh lime juice—so eight limes should make 1 cup of fresh lime juice. Obviously, some limes are juicer than others and smaller limes will likely yield less juice than larger ones.

Jai Ganesh · 2024-07-31 00:11:23

2237) Luminosity

Gist

Luminosity is an absolute measure of radiated electromagnetic energy (light) per unit time, and is synonymous with the radiant power emitted by a light-emitting object. In astronomy, luminosity is the total amount of electromagnetic energy emitted per unit of time by a star, galaxy, or other astronomical objects.

Summary

Luminosity is the quality of something that gives off light or shines with reflected light. The most noticeable quality of a large, sparkly diamond is its luminosity.

You might describe a bright and lively oil painting in terms of its luminosity, or marvel at the luminosity of a brilliant sunset. Astronomers use the word luminosity to talk about a specific property of physics, the energy given of by an astronomical object in a certain amount of time. There's a direct correlation between this amount of energy and the object's brightness. The Latin root is lumen, meaning "light."

Luminosity, in astronomy, the amount of light emitted by an object in a unit of time. The luminosity of the Sun is 3.846 × {10}^{26} watts (or 3.846 × {10}^{33} ergs per second). Luminosity is an absolute measure of radiant power; that is, its value is independent of an observer’s distance from an object. Astronomers usually refer to the luminosity of an object in terms of solar luminosities, with one solar luminosity being equal to the luminosity of the Sun. The most luminous stars emit several million solar luminosities. The most luminous supernovae shine with {10}^{17} solar luminosities. The dim brown dwarfs have luminosities a few millionths that of the Sun.

Details

Luminosity is an absolute measure of radiated electromagnetic energy (light) per unit time, and is synonymous with the radiant power emitted by a light-emitting object. In astronomy, luminosity is the total amount of electromagnetic energy emitted per unit of time by a star, galaxy, or other astronomical objects.

In SI units, luminosity is measured in joules per second, or watts. In astronomy, values for luminosity are often given in the terms of the luminosity of the Sun, L⊙. Luminosity can also be given in terms of the astronomical magnitude system: the absolute bolometric magnitude of an object is a logarithmic measure of its total energy emission rate, while absolute magnitude is a logarithmic measure of the luminosity within some specific wavelength range or filter band.

In contrast, the term brightness in astronomy is generally used to refer to an object's apparent brightness: that is, how bright an object appears to an observer. Apparent brightness depends on both the luminosity of the object and the distance between the object and observer, and also on any absorption of light along the path from object to observer. Apparent magnitude is a logarithmic measure of apparent brightness. The distance determined by luminosity measures can be somewhat ambiguous, and is thus sometimes called the luminosity distance.

Measurement

When not qualified, the term "luminosity" means bolometric luminosity, which is measured either in the SI units, watts, or in terms of solar luminosities (L☉). A bolometer is the instrument used to measure radiant energy over a wide band by absorption and measurement of heating. A star also radiates neutrinos, which carry off some energy (about 2% in the case of the Sun), contributing to the star's total luminosity. The IAU has defined a nominal solar luminosity of 3.828×{10}^{26} W to promote publication of consistent and comparable values in units of the solar luminosity.

While bolometers do exist, they cannot be used to measure even the apparent brightness of a star because they are insufficiently sensitive across the electromagnetic spectrum and because most wavelengths do not reach the surface of the Earth. In practice bolometric magnitudes are measured by taking measurements at certain wavelengths and constructing a model of the total spectrum that is most likely to match those measurements. In some cases, the process of estimation is extreme, with luminosities being calculated when less than 1% of the energy output is observed, for example with a hot Wolf-Rayet star observed only in the infrared. Bolometric luminosities can also be calculated using a bolometric correction to a luminosity in a particular passband.

The term luminosity is also used in relation to particular passbands such as a visual luminosity of K-band luminosity. These are not generally luminosities in the strict sense of an absolute measure of radiated power, but absolute magnitudes defined for a given filter in a photometric system. Several different photometric systems exist. Some such as the UBV or Johnson system are defined against photometric standard stars, while others such as the AB system are defined in terms of a spectral flux density.

Stellar luminosity

A star's luminosity can be determined from two stellar characteristics: size and effective temperature. The former is typically represented in terms of solar radii, R⊙, while the latter is represented in kelvins, but in most cases neither can be measured directly. To determine a star's radius, two other metrics are needed: the star's angular diameter and its distance from Earth. Both can be measured with great accuracy in certain cases, with cool supergiants often having large angular diameters, and some cool evolved stars having masers in their atmospheres that can be used to measure the parallax using VLBI. However, for most stars the angular diameter or parallax, or both, are far below our ability to measure with any certainty. Since the effective temperature is merely a number that represents the temperature of a black body that would reproduce the luminosity, it obviously cannot be measured directly, but it can be estimated from the spectrum.

An alternative way to measure stellar luminosity is to measure the star's apparent brightness and distance. A third component needed to derive the luminosity is the degree of interstellar extinction that is present, a condition that usually arises because of gas and dust present in the interstellar medium (ISM), the Earth's atmosphere, and circumstellar matter. Consequently, one of astronomy's central challenges in determining a star's luminosity is to derive accurate measurements for each of these components, without which an accurate luminosity figure remains elusive. Extinction can only be measured directly if the actual and observed luminosities are both known, but it can be estimated from the observed colour of a star, using models of the expected level of reddening from the interstellar medium.

In the current system of stellar classification, stars are grouped according to temperature, with the massive, very young and energetic Class O stars boasting temperatures in excess of 30,000 K while the less massive, typically older Class M stars exhibit temperatures less than 3,500 K. Because luminosity is proportional to temperature to the fourth power, the large variation in stellar temperatures produces an even vaster variation in stellar luminosity. Because the luminosity depends on a high power of the stellar mass, high mass luminous stars have much shorter lifetimes. The most luminous stars are always young stars, no more than a few million years for the most extreme. In the Hertzsprung–Russell diagram, the x-axis represents temperature or spectral type while the y-axis represents luminosity or magnitude. The vast majority of stars are found along the main sequence with blue Class O stars found at the top left of the chart while red Class M stars fall to the bottom right. Certain stars like Deneb and Betelgeuse are found above and to the right of the main sequence, more luminous or cooler than their equivalents on the main sequence. Increased luminosity at the same temperature, or alternatively cooler temperature at the same luminosity, indicates that these stars are larger than those on the main sequence and they are called giants or supergiants.

Additional Information

A glance at the night sky above Earth shows that some stars are much brighter than others. However, the brightness of a star depends on its composition and how far it is from the planet.

Astronomers define star brightness in terms of apparent magnitude — how bright the star appears from Earth — and absolute magnitude — how bright the star appears at a standard distance of 32.6 light-years, or 10 parsecs. (A light-year is the distance light travels in one year — about 6 trillion miles, or 10 trillion kilometers.) Astronomers also measure luminosity — the amount of energy (light) that a star emits from its surface.

Measuring star brightness is an ancient idea, but today astronomers use more precise tools to obtain the calculation. Specifically, they use the electromagnetic spectrum, focusing on the wavelengths visible to the human eyes. Every star has a distinctive spectrum of light, which to our eyes is rendered as a color.

While many stars have a consistent brightness, there are more than 100,000 known and cataloged variable stars. (Even our own sun is variable, varying its energy output by about 0.1 percent, or one-thousandth of its magnitude, during its 11-year solar cycle.)

Variable stars can change over the short term or over the long term. Astronomers tend to talk much more about short-term variable stars, unless they are interested in learning about stellar evolution or cosmology (which is the study of the universe's history.)

Short-term variable stars come in two flavors. One is intrinsic, meaning their luminosity changes due to features such as expansion, contraction, eruption or pulsation. The second is extrinsic, meaning that a star or planet passes in front of the star and blocks the light, or that the change is due to stellar rotation.

There are lots of kinds of short-term variable stars. The most commonly cited one is Cepheid variables, which are extremely luminous stars that have short pulsation periods.

The variations in the luminosity allow astronomers to calculate how far away these Cepheids are, making them useful "measuring sticks" if the stars are embedded in galaxies or nebulae. Ultimately, this allows us to estimate the expansion of the universe by tracking the Hubble Constant, although scientists disagree on how fast the expansion is proceeding.

Other types of short-term variable stars include cataclysmic variables, which brighten due to outbursts such as during supernova explosions, or eruptic variables whose brightness varies during eruptions on the surface.

As for long-term variable stars, we know of at least a few stars that have changed brightness over many centuries. The North Star or Polaris, for example, could have been as much as 4.6 times brighter in ancient times than it was today. A 2014 study noted that the star dimmed for the past few decades, but then drastically brightened again.

Finally, there are stars that are variable for extrinsic reasons. Examples include eclipsing binary stars, when one star passes in front of another and temporarily dims the light of the furthest star from coming to Earth. Another example is a rotating star such as a pulsar. Pulsars are rapidly rotating cores of old stars that exploded into supernovas, whose electromagnetic radiation is only visible when the beam is directed at Earth.

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Jai Ganesh · 2024-07-31 22:28:58

2238) Airborne diseases

Gist

Airborne diseases are bacteria or viruses that are most commonly transmitted through small respiratory droplets. These droplets are expelled when someone with the airborne disease sneezes, coughs, laughs, or otherwise exhales in some way.

Summary

How Airborne Transmission Works

Airborne diseases are bacteria or viruses that are most commonly transmitted through small respiratory droplets. These droplets are expelled when someone with the airborne disease sneezes, coughs, laughs, or otherwise exhales in some way. These infectious vehicles can travel along air currents, linger in the air, or cling to surfaces, where they are eventually inhaled by someone else.

Airborne transmission can occur over relatively long distances and spans of time. If you go into the bathroom that someone coughed in minutes before, it could be a danger. This makes it possible for airborne diseases to infect larger numbers of people and more difficult to determine the causes due to a lack of person-to-person contact.

Airborne transmission has varying capabilities. Airborne diseases can travel distances greater than 6 feet and remain infectious in the air from minutes to hours. This largely depends on the type of ventilation and preventative measures inside the building.

Airborne Diseases

Few diseases are predominantly airborne. Most diseases that spread through the air are also contagious through larger respiratory droplet transmission. This type of infection occurs when people are within 6 feet of each other.

Measles

Measles is one of the most contagious diseases, affecting up to 90% of the people close to a person with the disease. It’s a virus that lives in the mucus of the nose and throat and is spread through coughing and sneezing. The measles virus survives for up to 2 hours in the air once the infected person leaves an area.

Tuberculosis (TB)

Tuberculosis, or TB, is a bacterial disease of the lungs and throat. When a person with TB coughs, speaks, or laughs, the TB bacteria are released into the air. TB is not transmitted through touching, kissing, or sharing food.

Other Diseases

Measles and TB are airborne-exclusive diseases. There are several other diseases that spread through respiratory droplets, which can exist either in the air or on surfaces. These diseases include:

* Chickenpox
* Influenza
* Pertussis (whooping cough)
* Respiratory Syncytial Virus (RSV).

Preventing Airborne Diseases

Most diseases can be traced back to a person’s home or workplace. Practicing healthy behaviors while indoors is crucial for preventing the spread of airborne diseases. Some of the best and simplest preventative measures are:

* Cough or sneeze into a handkerchief or into your elbow.
* Wash your hands frequently.
* Regularly clean common surfaces, like doorknobs, counters, handles, and more.

Additionally, make sure indoor locations have proper ventilation that can keep bacteria and viruses out of the air. Stagnant air encourages diseases to spread.

Details

Many different diseases can be spread by airborne pathogens. Learning how to protect against them is important for your health and the health of your community.

You can catch some diseases simply by breathing. These are called airborne diseases.

Airborne disease can spread when people with certain infections cough, sneeze, or talk, spewing nasal and throat secretions into the air. Some viruses or bacteria take flight and hang in the air or land on other people or surfaces.

When you breathe in airborne pathogenic organisms, they take up residence inside you. You can also pick up germs when you touch a surface that harbors them, and then touch your own eyes, nose, or mouth.

Because these diseases travel in the air, they’re hard to control. Keep reading to learn more about the common types of airborne diseases and what you can do to protect yourself from catching them.

Types of airborne diseases

Many diseases are spread through the air, including these:

A rapidly spreading coronavirus, SARS-CoV-2, and the disease it causes, COVID-19, has been responsible for millions of infections and hundreds of thousands of deaths globally in 2020. Information on coronavirus and COVID-19 is constantly being updated as a result.

While the coronavirus that causes COVID-19 is not generally considered to be airborne, there may be some situationsTrusted Source in which the virus can act like an airborne disease. These include certain clinical settings in which people are receiving intensive medical treatment. In usual situations, SARS-CoV-2 is spread through respiratory droplets after a person coughs or sneezes, but these droplets are larger than what is considered airborne.

The most common symptoms of COVID-19 include fever, cough, fatigue, and shortness of breath. If you experience these symptoms, see a doctor immediately.

The common cold

Millions of cases of the common cold occur each year in the United States. Most adults get two or three colds a year. Children tend to get them more frequently.

The common cold is the top reason for absences at school and work. There are many viruses that can cause a cold, but it’s usually a rhinovirus.

Influenza

Most of us have some experience with the flu. It spreads so easily because it’s contagious about a day before you notice the first symptoms. It remains contagious for another 5 to 7 days. If you have a weakened immune system for any reason, you can spread it to others longer than that.

There are many strains of the flu, and they are constantly changing. That makes it difficult for your body to develop immunities.

Chickenpox

Chickenpox is caused by the varicella-zoster virus. If you have chickenpox, you can spread it for a day or two before you get the telltale rash. It takes up to 21 days after exposure for the disease to develop.

Most people get chickenpox only once, and then the virus goes dormant. Should the virus reactivate later in life, you get a painful skin condition called shingles.

If you haven’t had chickenpox, you can contract it from someone with shingles.

Mumps

Mumps is another very contagious viral disease. You can spread it before symptoms appear and for up to 5 days after. Mumps used to be quite common in the United States, but rates have declined by 99 percent due to vaccination.

From January 1 to January 25, 2020, 70 cases in the United States were reported to the CDC. Outbreaks tend to occur in densely populated environments.

Measles

Measles is a very contagious disease, particularly in crowded conditions.

The virus that causes measles can remain active in the air or on surfaces for up to 2 hours. You’re able to transmit it to others up to 4 days before and 4 days after the measles rash appears.

Most people get the measles only once.

Measles is a leading cause of death among children worldwide and was responsible for 140,000 death in 2018. It’s estimated that the measles vaccine prevented around 23 million deaths from 2000 to 2018.

The disease is less common in the United States and occurs mostly in people who haven’t been vaccinated. There were 1,282 cases reported in 2019. As of March 2, 2020, there have been 12 confirmed cases in 2020.

Whooping cough (pertussis)

This respiratory illness causes swelling of the airways that results in a persistent hacking cough. It’s at the height of contagiousness for about 2 weeks after the coughing starts.

Worldwide, there are about 24.1 million cases of whooping cough every year, resulting in 160,700 deaths.

In 2018, there were 15,609 reported cases in the United States.

Tuberculosis (TB)

TB, also known as consumption, is an airborne disease. This is a bacterial infection that doesn’t spread easily. You generally have to be in close contact with a person who has it for a long time.

You can contract TB without becoming ill or transmitting it to others.

About 1.4 billion people worldwide have TB. Most aren’t sick. About 10 million people worldwide have active TB.

People with a weakened immune system have the greatest risk of developing the disease. Symptoms can appear within days of exposure. For some, it takes months or years to activate.

When the disease is active, bacteria rapidly multiply and attack the lungs. It can spread through your bloodstream and lymph nodes to other organs, bones, or skin.

Diphtheria

Once a major cause of sickness and death in children, diphtheria is now rare in the United States. Due to widespread vaccination, fewer than five cases have been reported in the past decade.

Worldwide, there were about 7,100 cases of diphtheria in 2016, but it may be underreported.

The disease injures your respiratory system and can damage your heart, kidneys, and nerves.

Symptoms

Airborne diseases usually result in one or more of the following symptoms:

* inflammation of your nose, throat, sinuses, or lungs
* coughing
* sneezing
* congestion
* runny nose
* sore throat
* swollen glands
* headache
* body aches
* loss of appetite
* fever
* fatigue

Chickenpox causes an itchy rash that usually starts on your chest, face, and back before spreading over the rest of your body. Within a few days, fluid-filled blisters form. The blisters burst and scab over in about a week.

The measles rash can take as long as 7 to 18 days to appear after you’ve been exposed. It generally starts on your face and neck, and then spreads over the course of a few days. It fades within a week.

Serious complications of measles include:

* ear infections
* diarrhea
* dehydration
* severe respiratory infection
* blindness
* swelling of the brain, or encephalitis

Whooping cough gets its name from its main symptom, a severe hacking cough, which is usually followed by a forceful intake of air.

Symptoms of TB vary depending on which organs or body systems are affected and may include coughing up sputum or blood.

Diphtheria can cause marked swelling in your neck. This can make it difficult to breathe and swallow.

Complications from airborne diseases are more likely to affect the very young, the very old, and people with a compromised immune system.

Treatment for common airborne diseases
For most airborne diseases, you’ll need plenty of rest and fluids. Further treatment depends on your specific illness.

Some airborne diseases, such as chickenpox, have no targeted treatment. However, medications and other supportive care can help relieve symptoms.

Some, such as the flu, can be treated with antiviral drugs.

Treatment for infants with whooping cough can include antibiotics, and hospitalization is often needed.

There are drugs to treat and cure TB, although some strains of TB are drug resistant. Failure to complete the course of medicine can lead to drug resistance and return of symptoms.

If caught early enough, diphtheria can be successfully treated with antitoxins and antibiotics.

Incidence
Airborne diseases happen all around the world and affect virtually everyone.

They spread easily in close quarters, such as schools and nursing homes. Large outbreaks tend to occur under crowded conditions and in places where hygiene and sanitation systems are poor.

Incidence is lower in countries where vaccines are widely available and affordable.

Outlook

Most airborne diseases run their course within a few weeks. Others, like whooping cough, can last for months.

Serious complications and longer recovery time are more likely if you have a weakened immune system or if you don’t have access to good medical care. In some cases, airborne diseases can be fatal.

What you can do to prevent spreading an airborne disease

Although it’s impossible to completely avoid airborne pathogens, there are some things you can do to lower your chances of getting sick:

* Avoid close contact with people who have active symptoms of disease.
* Stay home when you’re sick. Don’t let vulnerable people come in close contact with you.
* If you must be around others, wear a face mask to prevent spreading or breathing in germs.
* Cover your mouth when you cough or sneeze. Use a tissue or your elbow to cut down on the possibility of transmitting germs on your hands.
* Wash your hands thoroughly (at least 20 seconds) and often, especially after sneezing or coughing.
* Avoid touching your face or other people with unwashed hands.

Vaccines can reduce your chances of getting some airborne diseases. Vaccines also lower the risk for others in the community. Airborne diseases that have vaccines include:

* chickenpox
* diphtheria
* influenza: vaccine updated every year to include strains most likely to spread in the coming season
* measles: usually combined with vaccine for mumps and rubella, and is known as the MMR vaccine
* mumps: MMR vaccine
* TB: not generally recommended in the United States
* whooping cough

In developing countries, mass immunization campaigns are helping to lower the transmission rates of some of these airborne diseases.

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Jai Ganesh · 2024-08-01 13:23:40

2239) Mint lemonade

Details

Mint lemonade is lemonade flavored with mint. It may be made with whole mint leaves, mint-flavored syrup, or pureed mint leaves, and may be served over ice cubes or blended with ice into a slush or smoothie. It is sometimes called a virgin mojito.

It is found in North America, Europe, Latin America, and the Middle East, and is attested since the early 20th century.

Preparation

The mint flavor may be added to lemonade in various ways:

* Fresh mint leaves, sometimes simply as a garnish.
* Muddled mint leaves.
* Processing the mint with the lemon juice in a blender.
* Mint syrup, made by simmering mint leaves in sugar water.
* Crème de menthe liqueur.

It may be mixed with still or sparkling water.

It may be served over ice, or blended with ice to make a slush, smoothie, or granita.

There are also bottled versions.

Variants

Variants may add ingredients such as ginger, maple syrup, lime juice, black salt and apple juice.

Adding spirits

Various spirits may be added to it, including arak, tequila ("mint margarita"), bourbon (a "lemon and mint julep"), gin, etc.

As a flavor

Mint lemonade may also be made into sorbets, ice pops, and so on.

Names

In the Arab world it is called “limon na-naa”.

In Israel, it is called limonana, a portmanteau of limon Hebrew: 'lemon' and naʿnaʿ Hebrew: 'mint'. The word was coined for an advertising campaign to promote bus advertising, in which various celebrities were shown promoting a drink called "Limonana", a blend of lemon and mint, which was in the end revealed to be fictitious.

Additional Information

Fresh mint and lemon combine for a sweet homemade lemonade. Mint Lemonade is a refreshing, ever-so-tasty summer drink that my whole family loves.

Mint Lemonade is a refreshing balance of tangy and sweet deliciousness. It’s perfect for summer porch sitting. It’s a simple twist on the classic summer drink made with real lemons and fresh mint.

Mint is easy to grow and was always in abundance. Growing up we would grab some mint and mix it up with some powdered lemonade and sip our treat.

Mint Lemonade is a refreshing balance of tangy and sweet deliciousness. It’s perfect for summer porch sitting. It’s a simple twist on the classic summer drink made with real lemons and fresh mint.

Mint Lemonade Recipe

* Bring sugar and 1 cup of water to a boil. Stir until the sugar has dissolved. Remove from the heat and add mint leaves. Cool to room temperature.
* In a large pitcher, stir together ice cold water and lemon juice. Remove the large mint pieces from the sugar water and to the pitcher of water and lemon juice.
* Pour over a glass of ice. Garnish with mint and a lemon slice.

Jai Ganesh · 2024-08-02 13:34:45

2240) Lingonberry juice

Details

Lingonberry juice is juice made of lingonberries. Lingonberry juice does not need preservatives like other juices as lingonberries contain benzoic acid.

Drinking lingonberry juice can reduce the risk for urinary tract infection, according to a study made by the University Hospital in Oulu, Finland.

Vargtass is a mix made of vodka and lingonberry juice.

What are the health benefits of lingonberries?

* Control weight. A trial conducted on mice found that lingonberries can prevent many adverse effects caused by a high-fat diet. ...
* Fight cancer cells. ...
* Improve cardiovascular health. ...
* Prevent colon cancer. ...
* Protect eye health. ...
* Reduce inflammation. ...
* Treat diabetes.

Additional Information

The lingonberry is a small, bright red berry that belongs to the same plant family as the blueberry and cranberry. Health benefits of lingonberries include that they help control weight, fight cancer cells, prevent colon cancer, and other benefits.

Jai Ganesh · 2024-08-02 18:32:48

2241) Electrostatics

Gist

Electrostatics is a branch of physics that deals with the phenomena and properties of stationary or slow-moving electric charges. Electrostatic phenomena arise from the forces that electric charges exert on each other and are described by Coulomb's law.

Summary

Electrostatics, the study of electromagnetic phenomena that occur when there are no moving charges—i.e., after a static equilibrium has been established. Charges reach their equilibrium positions rapidly, because the electric force is extremely strong. The mathematical methods of electrostatics make it possible to calculate the distributions of the electric field and of the electric potential from a known configuration of charges, conductors, and insulators. Conversely, given a set of conductors with known potentials, it is possible to calculate electric fields in regions between the conductors and to determine the charge distribution on the surface of the conductors. The electric energy of a set of charges at rest can be viewed from the standpoint of the work required to assemble the charges; alternatively, the energy also can be considered to reside in the electric field produced by this assembly of charges. Finally, energy can be stored in a capacitor; the energy required to charge such a device is stored in it as electrostatic energy of the electric field.

Coulomb’s law

Static electricity is a familiar electric phenomenon in which charged particles are transferred from one body to another. For example, if two objects are rubbed together, especially if the objects are insulators and the surrounding air is dry, the objects acquire equal and opposite charges and an attractive force develops between them. The object that loses electrons becomes positively charged, and the other becomes negatively charged. The force is simply the attraction between charges of opposite sign. The properties of this force were described above; they are incorporated in the mathematical relationship known as Coulomb’s law.

Details

Electrostatics is a branch of physics that studies slow-moving or stationary electric charges.

Since classical times, it has been known that some materials, such as amber, attract lightweight particles after rubbing. The Greek word for amber, (ḗlektron), was thus the source of the word electricity. Electrostatic phenomena arise from the forces that electric charges exert on each other. Such forces are described by Coulomb's law.

There are many examples of electrostatic phenomena, from those as simple as the attraction of plastic wrap to one's hand after it is removed from a package, to the apparently spontaneous explosion of grain silos, the damage of electronic components during manufacturing, and photocopier and laser printer operation.

The electrostatic model accurately predicts electrical phenomena in "classical" cases where the velocities are low and the system is macroscopic so no quantum effects are involved. It also plays a role in quantum mechanics, where additional terms also need to be included.

Coulomb's law

Coulomb's law states that:

'The magnitude of the electrostatic force of attraction or repulsion between two point charges is directly proportional to the product of the magnitudes of charges and inversely proportional to the square of the distance between them'.

The force is along the straight line joining them. If the two charges have the same sign, the electrostatic force between them is repulsive; if they have different signs, the force between them is attractive.

Electric field

The electric field, E, in units of Newtons per Coulomb or volts per meter, is a vector field that can be defined everywhere, except at the location of point charges (where it diverges to infinity).

Electric field lines are useful for visualizing the electric field. Field lines begin on positive charge and terminate on negative charge. They are parallel to the direction of the electric field at each point, and the density of these field lines is a measure of the magnitude of the electric field at any given point.

Gauss's law

Gauss's law states that "the total electric flux through any closed surface in free space of any shape drawn in an electric field is proportional to the total electric charge enclosed by the surface." Many numerical problems can be solved by considering a Gaussian surface around a body.

Electrostatic approximation

Electrostatics does not require the absence of magnetic fields or electric currents. Rather, if magnetic fields or electric currents do exist, they must not change with time, or in the worst-case, they must change with time only very slowly. In some problems, both electrostatics and magnetostatics may be required for accurate predictions, but the coupling between the two can still be ignored. Electrostatics and magnetostatics can both be seen as non-relativistic Galilean limits for electromagnetism. In addition, conventional electrostatics ignore quantum effects which have to be added for a complete description.

Electrostatic pressure

On a conductor, a surface charge will experience a force in the presence of an electric field. This force is the average of the discontinuous electric field at the surface charge.

Additional Information

Electrostatics is the study of electric charges that are fixed. It includes an study of the forces that exist between charges as defined by Coulomb’s Law. The following concepts are involved in electrostatics: Electric charge, electric field, and electrostatic force.

Electrostatic forces are non contact forces that can push or pull on items without coming into contact with them. A storm cloud’s internal accumulation of static electricity produces lightning.

What is Electrostatics?

Electrostatics is a field of physics that studies the phenomena and behaviours of stationary or slow-moving electric charges. Coulomb’s law describes electrostatic processes, which result from the forces that electric charges apply to one another. even if forces generated by electrostatics appear to be rather little.

What is Electric Charge?

Electric charge is a fundamental property of matter that determines how it interacts with electromagnetic fields. When charges are stationary, they produce an electric field around them, and when in motion, they produce a magnetic field as well. Electric charge comes in two types: positive and negative. Like charges repel whereas unlike charges attract.

Types of Charged Particles

There are primarily two types of charged particles which are discussed below:

Positively Charged Particles

Protons are the positively charged particles that are found in the nucleus of an atom. Protons have a mass of about 1 u. A particle gain positive charge when it lose electrons.

Negatively Charged Particles

Electrons are Negatively charged subatomic particles that surround the nucleus of an atom. Electrons have a much smaller mass of about 0.0005u. Electrons are located outside the nucleus in the outermost regions of the atom, called electron shells. A particle gain negative charge when its gains electron from other particle.

After from positive and negatively charged particles, there are neutral particles which are discussed below:

Neutral Particles

Neutrons are Neutral subatomic particles that are also found in the nucleus of an atom. Neutrons have a mass of about 1 u.

Coulomb’s law

Coulomb’s law states that the magnitude of the electrostatic force F between two point charges q1 and q2 is directly proportional to the product of the magnitudes of the charges and inversely proportional to the square of the distance between their centers.

Superposition Principle

Total force exerted on a charged particle by multiple charged particles is the vector sum of the forces exerted by each individual particle. This principle holds true because the electrostatic force obeys Coulomb’s law, which is a linear relationship.

What is Electric Field?

The electric field at a given point is defined as the force per unit charge experienced by a small positive test charge q0 placed at that point.

The electric field emanates radially outward when q is positive, and conversely, it converges radially inward when q is negative.

Electric Field Lines

These are imaginary lines drawn in a way that the tangent at any given point on the line represents the direction of the electric field at that point. Some key characteristics of field lines include:

* They form continuous unbroken curves.
* They never intersect.
* They extend from positive to negative charges, there can be no closed loops.

Electric Flux

Electric flux quantifies the number of electric field lines passing through a surface.

What is an Electric Dipole?

An electric dipole consists of two equal and opposite electric charges separated by a distance. These charges create an electric field around the dipole.

Gauss’ law

Gauss’ law for electrostatics states that the total electric flux through a closed surface is proportional to the enclosed electric charge. This includes the bound charge due to polarization.

Conductors, Insulators, and Semiconductors

Conductors: Conductors are materials with low electrical resistivity, strong electrical conductivity, and ease of electricity conductivity. Charge can flow across conductors when a voltage is supplied to them.

Semiconductors: Semiconductors are materials with a conductivity value in between that of an insulator and a conductor. When required, semiconductors can function as both a conductor and an insulator.

Insulators : Insulators are materials that don’t conduct electricity. Current cannot flow through insulators. Insulators are used to shield ourselves from the potentially harmful effects of electricity passing via conductors.

Dielectric Strength

Dielectric strength refers to an insulating material’s electrical strength. It is the highest electric field that a substance is capable of withstanding before degrading and turning electrically conductive.

Surface Charge Density

Surface charge density refers to the amount of electric charge per unit area on a two-dimensional surface. It is a measurement of the total electric charge that has built up on a surface.

Electric Potential (V)

Electric potential (also known as voltage) is the difference in potential energy per unit charge between two points in an electric field. It is a scalar with the volt (V) as its unit.

Equipotential Surface

An equipotential surface is a region in space where all points have the same potential. Although it is typically used in reference to scalar potentials, vector potentials can also be considered.

Charged Particles in Electric Field

When a charged particle enters an electric field, it accelerates in the direction of the field lines. The direction of the electric field is always the force acting on the particle. The particle in the electric field will follow a straight path. However, the particle will either be attracted to or repelled by the charge depending on its polarity. A charged particle experiences force regardless of its velocity. The particle’s path is bent by the field, which is perpendicular to the velocity.

Combined Field Due to Two Point Charges

If there are many source charges, each contributes to the electric field at every site in their area. The electric field at a point in space close to the source charges is the vector sum of the electric fields caused by each source charge. Assume that the set of source charges consists of two charged particles. The electric field vector resulting from the first charged particle plus the electric field vector resulting from the second charged particle equals the electric field at point P.

Determining the overall electric field at place P is a vector addition since the two electric field vectors that contribute to it are vectors.

Therefore, the electric field intensity at each point resulting from a system or group of charges is equal to the vector sum of the electric field intensities attributable to individual charges at the same site. The vector sum of electric field intensities is given by E=E1+E2+E3+..+En.

Electric Lines of Force

Electric lines of force are imaginary lines or curves formed across an electric field. The direction that a tiny free positive charge will go along a line of force is known as its direction. Since two tangents can be traced to the two lines of force at the intersection, electric lines of force never cross. This indicates that there will be two electric field directions at the intersection, which is not feasible.

Jai Ganesh · 2024-08-03 14:38:02

2242) Lychee

Gist

The lychee (Litchi chinensis) — also known as litchi or lichee — is a small tropical fruit from the soapberry family. Other popular fruits in this family include rambutan and longan. Lychees are grown in subtropical regions throughout the world and especially popular in their native China, as well as Southeast Asia.

Details

Lychee is a monotypic taxon and the sole member in the genus Litchi in the soapberry family, Sapindaceae.

There are three distinct subspecies of lychee. The most common is the Indochinese lychee found in South China, Malaysia, and northern Vietnam. The other two are the Philippine lychee (locally called alupag or matamata) found only in the Philippines and the Javanese lychee cultivated in Indonesia and Malaysia. The tree has been introduced throughout Southeast Asia and South Asia. Cultivation in China is documented from the 11th century. China is the main producer of lychees, followed by India, Vietnam, other countries in Southeast Asia, other countries in the South Asia, Madagascar, and South Africa. A tall evergreen tree, it bears small fleshy sweet fruits. The outside of the fruit is a pink-red, rough-textured soft shell.

Lychee seeds contain methylene cyclopropyl glycine which has caused hypoglycemia associated with outbreaks of encephalopathy in undernourished Indian and Vietnamese children who consumed lychee fruit.

Taxonomy

Litchi chinensis is the sole member of the genus Litchi in the soapberry family, Sapindaceae.

It was described and named by French naturalist Pierre Sonnerat in his account "Voyage aux Indes Orientales et à la Chine, fait depuis 1774 jusqu'à 1781" (translation: "Voyage to the East Indies and China, made between 1774 and 1781"), which was published in 1782. There are three subspecies, determined by flower arrangement, twig thickness, fruit, and a number of stamens.

* Litchi chinensis subsp. chinensis is the only commercialized lychee. It grows wild in southern China, northern Vietnam, and Cambodia. It has thin twigs, flowers typically have six stamens, fruit are smooth or with protuberances up to 2 mm (0.079 in).
* Litchi chinensis subsp. philippinensis (Radlk.) Leenh. It is common in the wild in the Philippines and rarely cultivated. Locally called alupag, mata-mata, or matamata due to its eye-like appearance when the fruit is opened, it has thin twigs, six to seven stamens, long oval fruit with spiky protuberances up to 3 mm (0.12 in).
* Litchi chinensis subsp. javensis. It is only known in cultivation, in Malaysia and Indonesia. It has thick twigs, flowers with seven to eleven stamens in sessile clusters, smooth fruit with protuberances up to 1 mm (0.039 in).

Description

Tree

Litchi chinensis is an evergreen tree that is frequently less than 15 m (49 ft) tall, sometimes reaching 28 m (92 ft). Its evergreen leaves, 12.5 to 20 cm (4.9 to 7.9 in) long, are pinnate, having 4 to 8 alternate, elliptic-oblong to lanceolate, abruptly pointed, leaflets,

The bark is grey-black, the branches a brownish-red. Its evergreen leaves are 12.5 to 20 cm (4.9 to 7.9 in) long, with leaflets in two to four pairs. Lychee are similar in foliage to the family Lauraceae, likely due to convergent evolution. They are adapted by developing leaves that repel water, and are called laurophyll or lauroid leaves.

Flowers grow on a terminal inflorescence with many panicles on the current season's growth. The panicles grow in clusters of ten or more, reaching 10 to 40 cm (3.9 to 15.7 in) or longer, holding hundreds of small white, yellow, or green flowers that are distinctively fragrant.

Fruit

The lychee bears fleshy fruits that mature in 80–112 days depending on climate, location, and cultivar. Fruits vary in shape from round to ovoid to heart-shaped, up to 5 cm long and 4 cm wide (2.0 in × 1.6 in), weighing approximately 20 g.

The thin, tough skin is green when immature, ripening to red or pink-red, and is smooth or covered with small sharp protuberances roughly textured. The rind is inedible but easily removed to expose a layer of translucent white flesh with a floral smell and a sweet flavor. The skin turns brown and dry when left out after harvesting.

The fleshy, edible portion of the fruit is an aril, surrounding one dark brown inedible seed that is 1 to 3.3 cm long and 0.6 to 1.2 cm wide (0.39–1.30 by 0.24–0.47 in). Some cultivars produce a high percentage of fruits with shriveled aborted seeds known as 'chicken tongues'. These fruits typically have a higher price, due to having more edible flesh. Since the floral flavor is lost in the process of canning, the fruit is usually eaten fresh.

Additional Information

Lychee, (Litchi chinensis), evergreen tree of the soapberry family (Sapindaceae), grown for its edible fruit. Lychee is native to Southeast Asia and has been a favourite fruit of the Cantonese since ancient times. The fruit is usually eaten fresh but can also be canned or dried. The flavour of the fresh pulp is aromatic and musky, and the dried pulp is acidic and very sweet.

History

Lychee is of local importance throughout much of Southeast Asia and is grown commercially in China and India. Its introduction into the Western world came when it reached Jamaica in 1775. The first lychee fruits in Florida—where the tree has attained commercial importance—are said to have ripened in 1916. To a lesser extent the tree has been cultivated around the Mediterranean, in South Africa, and in Hawaii.

Physical description and cultivation

The lychee tree develops a compact crown of foliage that is bright green year-round. The leaves are compound, composed of two to four pairs of elliptic to lanceolate leaflets that are 50–75 mm (2–3 inches) long. The flowers, small and inconspicuous, are borne in loose diverse terminal clusters, or panicles, sometimes 30 cm (12 inches) in length. The fruits are oval to round, strawberry-red in colour, and about 25 mm (1 inch) in diameter. The brittle outer covering encloses a translucent white fleshy aril and one large seed.

The tree is propagated by seed and by air layering, in which a branch is made to produce roots while still attached to the parent plant. When moved to a permanent orchard, lychee plants are set 7.5–10.5 metres (24.5–34.5 feet) apart. They require very little pruning and no unusual attention, though they should have abundant moisture around the roots most of the time. The trees come into production at three to five years of age.

Toxins

The consumption of lychee fruits has been linked to hypoglycemic encephalopathy and death in a number of children in India, Bangladesh, and Vietnam. The fruits and seeds contain the toxins hypoglycin A and methylene cyclopropyl-glycin, which inhibit the synthesis of glucose and can cause acute hypoglycemia. These toxins are more concentrated in unripe fruits, and their effects seem to be compounded in undernourished children or when consumed after a period of fasting.

Jai Ganesh · 2024-08-04 13:41:50

2243) Must

Details

Must (from the Latin vinum mustum; lit. 'young wine') is freshly crushed fruit juice (usually grape juice) that contains the skins, seeds, and stems of the fruit. The solid portion of the must is called pomace and typically makes up 7–23% of the total weight of the must. Making must is the first step in winemaking. Because of its high glucose content, typically between 10 and 15%, must is also used as a sweetener in a variety of cuisines. Unlike commercially sold grape juice, which is filtered and pasteurized, must is thick with particulate matter, opaque, and comes in various shades of brown and purple.

Winemaking

The length of time the pomace stays in the juice is critical for the final character of the wine. When the winemaker judges the time to be right, the juice is drained off the pomace, which is then pressed to extract the juice retained by the matrix. Yeast is added to the juice to begin the fermentation, while the pomace is often returned to the vineyard or orchard for use as fertilizer. A portion of selected unfermented must may be kept as Süssreserve, to be added as a sweetening component before bottling. Some winemakers create a second batch of wine from the used pomace by adding a quantity of water equivalent to the juice removed, letting the mixture sit for 24 hours, and draining off the liquid. This wine may be used as a drink for the employees of the winemaker or as a basis for some pomace brandies. Grappa, however, must by law be produced only from the pomace solids, with no water added.

Balsamico

The must is also an essential ingredient for the production of traditional balsamic vinegar, the special aged vinegar from the Emilia-Romagna region of Italy, protected under the European protected designation of origin system. Selected bacterial colonies or the lenta in superficie (slow surface) or lenta a truciolo (slow wood shavings) methods are used for acetification, and then there is a maturation phase. Both the acetification and the maturation take place in precious sessile oak (Quercus petraea), chestnut, oak, mulberry, and juniper barrels. After a minimum maturation period of 60 days, a group of expert technicians will test the resulting product analytically as well as organoleptically (via taste, aroma, the palette and other senses).

Mead

This term is also used by meadmakers for the unfermented honey-water mixture that becomes mead. The analogous term in beer brewing is wort.

In cookery

In ancient Greece, must condensed by boiling was called siraion and was used as a sweetener in the kitchen in various recipes (and as a syrup over teganitai (pancakes)). From the Greeks, the Romans in ancient Rome also used the condensed must in cooking, as a sweetener. Must was boiled in lead or bronze kettles into a milder concentrate called defrutum or a stronger concentrate called sapa. It was often used as a souring agent and preservative, especially in fruit dishes.

Currently, reduced must is used in Greek, other Balkan countries, French and Middle Eastern cookery as a syrup known as petimezi, pekmez or dibis. In Greece, petimezi is a basic ingredient for a must-custard known as moustalevria, and a sweet-meal known as soutzoukos, churchkhela. The Moustokoúloura or "must cookies" are also popular Greek cookies, which are based on a sweet dough made by kneading flour, olive oil, spice, and must. They are made in various shapes and sizes, and they are dark brown in color because of the must and the spice in them. In the wine making areas of South Africa must is used to make a sweet bun known as mosbolletjies.

The term petimezi is a Hellenized word of the Armenian/Trebizond term petmez. Petmez was a type of syrup that was made with berries of the White Mulberry tree; petmez was used in Byzantium (Trebizond was part of the Byzantine Empire), where White Mulberries grew in abundance, for their berries and for the silk worms that feed exclusively on Mulberry leaves.

Additional Information

The term 'must' is derived from the Latin term vinum mustum, meaning 'young wine'. Must is the name given to the freshly pressed grape juice, containing the skins, stems and stems of the grapes. Must is the first step in winemaking after the grapes have been harvested from the vine.

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Jai Ganesh · 2024-08-05 00:43:34

2244) Butter

Gist

What is butter made of? Usually butter is made from cow's milk, though goats, sheep and even yaks and buffaloes are used in some parts of the world. However, not all milk-producing animals can join the butter party – which is why you'll never get butter made from a camel.

Butter is a solid food most frequently made from cow's milk. Goat, buffalo, or sheep milk is also used to make butter. Since these are all mammals, butter is a dairy product. The dairy group is commonly the chief source of calcium in your diet.

Summary

Butter, a yellow-to-white solid emulsion of fat globules, water, and inorganic salts produced by churning the cream from cows’ milk. Butter has long been used as a spread and as a cooking fat. It is an important edible fat in northern Europe, North America, and other places where cattle are the primary dairy animals. In all, about a third of the world’s milk production is devoted to making butter.

Butter is one of the most highly concentrated forms of fluid milk. Twenty litres of whole milk are needed to produce one kilogram of butter. This process leaves approximately 18 litres of skim milk and buttermilk. Butter is a high-energy food, containing approximately 715 calories per 100 grams. It has a high content of butterfat, or milk fat (at least 80 percent), but is low in protein. Butter has substantial amounts of vitamin A and minor amounts of calcium, phosphorus, and vitamin D.

The colour of butter is caused by carotene and other fat-soluble pigments in the fat. In the United States vegetable colour can be added to commercial butter in order to improve yellowness. Whipped butter, made by whipping air or nitrogen gas into soft butter, is intended to spread more easily at refrigeration temperatures. Unsalted butter is often referred to as “sweet” butter. This should not be confused with “sweet cream” butter, which may or may not be salted. Reduced-fat, or “light,” butter usually contains about 40 percent milk fat.

The origin of butter is unknown, but presumably it dates back to the prehistoric stages of animal husbandry. With the advent of the cream separator in the late 19th century, the manufacture of butter moved from the farm to the factory. Continuous butter making, introduced after World War II, increased the efficiency and output of butter manufacture. There are two methods of continuous butter making: one involving the accelerated churning of normal cream and the other the utilization of reseparated high-fat cream. Well-made butter should be uniformly firm, waxy, and easy to slice and spread.

Details

What is butter?

Butter is a dairy product made from separating whole milk or cream into fat and buttermilk. The fat is compressed and chilled into blocks of butter. It can be used directly as a condiment or melted for frying or coating. Butter is also used in baking, such as in classic sponges and pastries, or for enriching sauces.

Butter can be bought salted or unsalted. Salt is used for preservation and flavour, but varies according to the breed of cow and its feed.

Butter is around 80 per cent fat and for this reason, many people prefer to use alternatives. Low-fat spreads are generally not suitable for baking so read packaging carefully.

Some cake recipes replace butter with a mild-tasting oil such as sunflower oil, which is ideal for those with a dairy intolerance or allergy. Cakes made in this way tend to be moister and last longer, but don't have the rich, buttery taste.

How to cook butter

Butter is a dairy product made from separating whole milk or cream into fat and buttermilk. The fat is compressed and chilled into blocks of butter. It can be used directly as a condiment or melted for frying or coating. Butter is also used in baking, such as in classic sponges and pastries, or for enriching sauces.

Butter can be bought salted or unsalted. Salt is used for preservation and flavour, but varies according to the breed of cow and its feed.

Butter is around 80 per cent fat and for this reason, many people prefer to use alternatives. Low-fat spreads are generally not suitable for baking so read packaging carefully.

Some cake recipes replace butter with a mild-tasting oil such as sunflower oil, which is ideal for those with a dairy intolerance or allergy. Cakes made in this way tend to be moister and last longer, but don't have the rich, buttery taste.

Recipe suggestions

Try brown butter over little shrimps on toast, drained gnocchi, or roasted cauliflower florets. In a simple pasta dish try a delicious brown butter linguine or chilled as a coating on radishes dipped in brown butter. Experiment with adding flavours to your butter, before using with our collection of flavoured butters.

Choose the best butter

Butter comes in many brands and packaging. French butter is prized for its superior quality, but can be pricier than others. It's best to buy the right type to suit your needs, most sweet and baking recipes call for unsalted butter, but salted butter is better for spreading onto toast and croissants.

How to store butter

Keep butter wrapped in its foil packaging or a butter dish in the fridge. Keep it away from pungent foods as it has a tendency to pick up the flavours.

For rubbed in cake mixtures, use butter straight from the fridge. For creamed cake mixtures, you'll need to take the butter out of the fridge a few hours before you're planning to use it – it needs to be soft in order to cream together well with the sugar.

Additional Information

Butter is a dairy product made from the fat and protein components of churned cream. It is a semi-solid emulsion at room temperature, consisting of approximately 80% butterfat. It is used at room temperature as a spread, melted as a condiment, and used as a fat in baking, sauce-making, pan frying, and other cooking procedures.

Most frequently made from cow's milk, butter can also be manufactured from the milk of other mammals, including sheep, goats, buffalo, and yaks. It is made by churning milk or cream to separate the fat globules from the buttermilk. Salt has been added to butter since antiquity to help preserve it, particularly when being transported; salt may still play a preservation role but is less important today as the entire supply chain is usually refrigerated. In modern times, salt may be added for taste. Food coloring is sometimes added to butter. Rendering butter, removing the water and milk solids, produces clarified butter, or ghee, which is almost entirely butterfat.

Butter is a water-in-oil emulsion resulting from an inversion of the cream, where the milk proteins are the emulsifiers. Butter remains a firm solid when refrigerated but softens to a spreadable consistency at room temperature and melts to a thin liquid consistency at 32 to 35 °C (90 to 95 °F). The density of butter is 911 g/L (15+1⁄4 oz/US pt). It generally has a pale yellow color but varies from deep yellow to nearly white. Its natural, unmodified color is dependent on the source animal's feed and genetics, but the commercial manufacturing process sometimes alters this with food colorings like annatto or carotene.

Production

Unhomogenized milk and cream contain butterfat in microscopic globules. These globules are surrounded by membranes made of phospholipids (fatty acid emulsifiers) and proteins, which prevent the fat in milk from pooling together into a single mass. Butter is produced by agitating cream, which damages these membranes and allows the milk fats to conjoin, separating from the other parts of the cream. Variations in the production method will create butters with different consistencies, mostly due to the butterfat composition in the finished product. Butter contains fat in three separate forms: free butterfat, butterfat crystals, and undamaged fat globules. In the finished product, different proportions of these forms result in different consistencies within the butter; butters with many crystals are harder than butters dominated by free fats.

Churning produces small butter grains floating in the water-based portion of the cream. This watery liquid is called buttermilk, although the buttermilk most commonly sold today is instead directly fermented skimmed milk. The buttermilk is drained off; sometimes more buttermilk is removed by rinsing the grains with water. Then the grains are "worked": pressed and kneaded together. When prepared manually, this is done using wooden boards called scotch hands. This consolidates the butter into a solid mass and breaks up embedded pockets of buttermilk or water into tiny droplets.

Commercial butter is about 80% butterfat and 15% water; traditionally-made butter may have as little as 65% fat and 30% water. Butterfat is a mixture of triglyceride, a triester derived from glycerol, and three of any of several fatty acid groups. Annatto is sometimes added by U.S. butter manufacturers without declaring it on the label because the U.S. allows butter to have an undisclosed flavorless and natural coloring agent (whereas all other foods in the U.S. must label coloring agents). The preservative lactic acid is sometimes added instead of salt (and as a flavor enhancer), and sometimes additional diacetyl is added to boost the buttery flavor (in the U.S., both ingredients can be listed simply as "natural flavors"). When used together in the NIZO manufacturing method, these two flavorings produce the flavor of cultured butter without actually fully fermenting.

Jai Ganesh · 2024-08-06 00:04:04

2245) Torrid Zone

Gist

The zone that receives direct sun rays throughout the year and experiences maximum heat is known as Torrid Zone. Torrid zone is an area that is between the Tropic of cancer in the northern hemisphere till the tropic of Capricorn in the southern hemisphere.

Summary

It is the area between the Tropic of Cancer (23.5 degrees North) and the Tropic of Capricorn (23.5 degrees South) because the midday Sunlight is directly overhead at a minimum each year in all latitudes, This zone receives the most heat from the Sun. The torrid zone is the region of the earth closest to the Equator. Usually, the Torrid Zone is extremely hot. This one has a wet and dry phase, but not the four seasons that residents of temperate countries further from the equator are familiar with. The atmosphere, ecology, and geographic characteristics are all influenced by the torrid region’s temperature. It can be found halfway in between the Tropic of Cancer and Capricorn.

Details

The torrid zone was the name given by ancient Greek and Roman geographers to the equatorial area of the Earth, so hot that it was impenetrable. That notion became a deterrent for European explorers until the 15th century.

Origin

Aristotle posited that the western half of the temperate zone on the other side of the world from Greece might be habitable and that, because of symmetry, there must be in the Southern Hemisphere a temperate zone corresponding to that in the northern. He thought, however, that the excessive heat in the torrid zone would prevent the exploration.

Strabo referred to:

"the meridian through Syene is drawn approximately along the course of the Nile from Meroë to Alexandria, and this distance is about ten thousand stadia; and Syene must lie in the centre of that distance; so that the distance from Syene to Meroë is five thousand stadia. And when you have proceeded about three thousand stadia in a straight line south of Meroë, the country is no longer inhabitable on account of the heat, and therefore the parallel though these regions, being the same as that through the Cinnamon-producing Country, must be put down as the limit and the beginning of our inhabited world on the South."

In 8 AD the poet Ovid wrote in his Metamorphoses.

"...the celestial vault is cut by two zones on the right and two on the left, and there is a fifth zone between, hotter than these, so did the providence of God mark off the enclosed mass with the same number of zones, and the same tracts were stamped upon the earth. The central zone of these may not be dwelt in by reason of the heat"

Pomponius Mela, the first Roman geographer, asserted that the Earth had two habitable zones, a north and a south one. The second population were known as Antichthones. However, it would be impossible to get into contact with each other because of the unbearable heat at the equator.

Proved wrong

Many Europeans had assumed that Cape Bojador, in Western Sahara, marked the beginning of the impenetrable torrid zone until 1434, when the Portuguese sailed past the cape and reported that no torrid zone existed.

Additional Information

Zones are nothing but a series of layers that are made due to the level of increase and decrease in moisture and temperature concerning increase in altitude. These are the different types of zones that are present on the planet.

Two especially significant parallels are known as the Tropic of Cancer and the Tropic of Capricorn. They encircle Earth at about 23 degrees, 27 minutes north and south of the Equator. The region between these parallels is called the tropics, or the torrid zone.

The torrid zone generally refers to the area of the earth near the Equator. The torrid zone is generally warm. It has a wet and dry season but does not have four seasons familiar to residents of the temperate zones further from the equator.

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Jai Ganesh · 2024-08-06 17:16:27

2246) Latex

Latex

Gist

Latex has a wide variety of applications, ranging from everyday items to more specialized uses. Natural rubber latex is most commonly used to make items like gloves, swim caps, chewing gum, mattresses, catheters, rubber bands, balloons, tennis shoes, and many other sporting goods.

Summary

Latex is a thick, creamy white, milky emulsion, although sometimes it may be a thin, clear, yellow or orange, aqueous suspension. Latex has many uses; from clothing to paint, but most importantly is rubber. Latex paint uses synthetic latex as a binder, which is not flammable, has little odor, and cures to form a dry paint film. Natural latex, which is nearly chemical free, is used in the manufacturing of natural latex mattresses, beauty application pads, and cushioning.

Latex is produced in vessels or special cells called laticifers, single cells, or strings of cells that form tubes, canals, or networks in various plant organs. This is quite different from the internal secretory tissues (pockets, cavities, or canals) in which most resin is produced.

Plant families that produce copious amounts of latex include:

* Euphorb family (Euphorbiaceae),
* milkweed family (Asclepiadaceae),
* mulberry family (Moraceae),
* dogbane family (Apocynaceae), and
* chicory tribe (Lactuceae) of the sunflower family (Asteraceae).

The first European notice of rubber was by Columbus in the Caribbean and by Cortez in Mexico, where crude rubber balls were noted as playthings of the American Indians.

In California and the southwest, many acres of guayule (Parthenium argentatum), pronounced "wa-YOO-lee," were planted to decrease the United States' dependence on foreign sources of rubber during World War II. The fields were later destroyed or abandoned with the advent of synthetic rubber.

The diminishing acreage of rubber plantations, an increasing demand, and the life-threatening latex allergy to Hevea rubber have prompted research interests in the development of alternative rubber sources, such as guayule, a native to Texas and Mexico.

Rubber rabbitbrush (Ericameria nauseosa) is a native source of latex, used in making rubber. However, there is no commercially viable method of extracting it yet. Native American peoples used rubber rabbitbrush as a source of rich yellow dye for blankets and rugs and the latex as a source of chewing gum.

Details

Latex is an emulsion (stable dispersion) of polymer microparticles in water. Latices are found in nature, but synthetic latices are common as well.

In nature, latex is found as a milky fluid, which is present in 10% of all flowering plants (angiosperms). It is a complex emulsion that coagulates on exposure to air, consisting of proteins, alkaloids, starches, sugars, oils, tannins, resins, and gums. It is usually exuded after tissue injury. In most plants, latex is white, but some have yellow, orange, or scarlet latex. Since the 17th century, latex has been used as a term for the fluid substance in plants, deriving from the Latin word for "liquid". It serves mainly as defense against herbivorous insects. Latex is not to be confused with plant sap; it is a distinct substance, separately produced, and with different functions.

The word latex is also used to refer to natural latex rubber, particularly non-vulcanized rubber. Such is the case in products like latex gloves, latex condoms, latex clothing, and balloons.

IUPAC definition.

Latex: Colloidal dispersion of polymer particles in a liquid.
Synthetic latex: Latex obtained as a product of an emulsion, mini-emulsion, micro-emulsion, or dispersion polymerization.

Biology:

Articulated laticifers

The cells (laticifers) in which latex is found make up the laticiferous system, which can form in two very different ways. In many plants, the laticiferous system is formed from rows of cells laid down in the meristem of the stem or root. The cell walls between these cells are dissolved so that continuous tubes, called latex vessels, are formed. Since these vessels are made of many cells, they are known as articulated laticifers. This method of formation is found in the poppy family and in the rubber trees (Para rubber tree, members of the family Euphorbiaceae, members of the mulberry and fig family, such as the Panama rubber tree Castilla elastica), and members of the family Asteraceae. For instance, Parthenium argentatum the guayule plant, is in the tribe Heliantheae; other latex-bearing Asteraceae with articulated laticifers include members of the Cichorieae, a clade whose members produce latex, some of them in commercially interesting amounts. This includes Taraxacum kok-saghyz, a species cultivated for latex production.

Non-articulated laticifers

In the milkweed and spurge families, on the other hand, the laticiferous system is formed quite differently. Early in the development of the seedling, latex cells differentiate, and as the plant grows these latex cells grow into a branching system extending throughout the plant. In many euphorbs, the entire structure is made from a single cell – this type of system is known as a non-articulated laticifer, to distinguish it from the multi-cellular structures discussed above. In the mature plant, the entire laticiferous system is descended from a single cell or group of cells present in the embryo.

The laticiferous system is present in all parts of the mature plant, including roots, stems, leaves, and sometimes the fruits. It is particularly noticeable in the cortical tissues. Latex is usually exuded as a white liquid, but is some cases it can be clear, yellow or red, as in Cannabaceae.

Productive species

Latex is produced by 20,000 flowering plant species from over 40 families. These include both dicots and monocots. Latex has been found in 14 percent of tropical plant species, as well as six percent of temperate plant species. Several members of the fungal kingdom also produce latex upon injury, such as Lactarius deliciosus and other milk-caps. This suggests it is the product of convergent evolution and has been selected for on many separate occasions.

Defense function

Latex functions to protect the plant from herbivores. The idea was first proposed in 1887 by Joseph F. James, who noted that latex of milkweed carries with it at the same time such disagreeable properties that it becomes a better protection to the plant from enemies than all the thorns, prickles, or hairs that could be provided. In this plant, so copious and so distasteful has the sap become that it serves a most important purpose in its economy.

Evidence showing this defense function include the finding that slugs will eat leaves drained of their latex but not intact ones, that many insects sever the veins carrying latex before they feed, and that the latex of Asclepias humistrata (sandhill milkweed) kills by trapping 30% of newly hatched monarch butterfly caterpillars.

Other evidence is that latex contains 50–1000× higher concentrations of defense substances than other plant tissues. These toxins include ones that are also toxic to the plant and consist of a diverse range of chemicals that are either poisonous or "antinutritive."

Latex is actively moved to the area of injury; in the case of Cryptostegia grandiflora, latex more than 70 cm from the site of injury is mobilized. The large hydrostatic pressure in this vine enables an extremely high flow rate of latex. In a 1935 report the botanist Catherine M. Bangham observed that "piercing the fruit stalk of Cryptostegia grandiflora produced a jet of latex over a meter long, and maintained [this jet] for several seconds."

The clotting property of latex is functional in this defense since it limits wastage and its stickiness traps insects and their mouthparts.

While there exist other explanations for the existence of latex including storage and movement of plant nutrients, waste, and maintenance of water balance that "[e]ssentially none of these functions remain credible and none have any empirical support".

Additional Information

latex, colloidal suspension, either the milky white liquid emulsion found in the cells of certain flowering plants such as the rubber tree (Hevea brasiliensis) or any of various manufactured water emulsions consisting of synthetic rubber or plastic.

The plant product is a complex mixture of substances, including various gum resins, fats, or waxes and, in some instances, poisonous compounds, suspended in a watery medium in which salts, sugars, tannins, alkaloids, enzymes, and other substances are dissolved. It is produced especially by the cells of plants of the subfamily Asclepiadoideae and others in the family Apocynaceae but also by those in the families Sapotaceae, Euphorbiaceae, Papaveraceae, Moraceae, and Asteraceae. The latex circulates in branched tubes that penetrate the tissues of the plant in a longitudinal direction, conducting substances and acting as an excretory reservoir. The chief commercial products of latex are rubber, gutta-percha, chicle, and balata. The latex of the opium poppy (Papaver somniferum) is the source of opium and the alkaloid morphine.

In the paint and coatings industry, aqueous dispersion polymers, or polymer emulsions called latexes, have come into widespread use since the late 1940s. These synthetic latexes include a binder dispersed in the water and form films by fusion of the plastic particles as the water evaporates. The properties of the films—such as hardness, flexibility, toughness, adhesion, colour retention, and resistance to chemicals—depend on the composition of the plastic. Polymers based on butadiene, styrene, vinyl acetate, and acrylic monomers have been used commercially.

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Jai Ganesh · 2024-08-07 00:03:06

2247) Raisin

Gist

The word "raisin" dates back to Middle English and is a loanword from Old French; in modern French, raisin means "grape", while a dried grape is a raisin sec, or "dry grape". The Old French word, in turn, developed from the Latin word racemus, "a bunch of grapes."

When it comes to raisins, the recommended portion size is 40g which, depending on the type of grape, can range from 100 to 200. The British Dietetic Association has shown that an innovative unit of measurement for regulating the right portion of food to be consumed is the hand!

Raisins are a good source of soluble fiber, which aids digestion and reduces stomach issues. Raisins also contain tartaric acid. Research shows this compound may lower inflammation, help your intestines work better, and help balance the bacteria in your gut.

Summary

Raisin, dried fruit of certain varieties of grapes. Raisin grapes were grown as early as 2000 bce in Persia and Egypt, and dried grapes are mentioned in the Bible (Numbers 6:3) during the time of Moses. David (Israel’s future king) was presented with “a hundred clusters of raisins” (1 Samuel 25:18), probably sometime during the period 1110–1070 bce. Early Greeks and Romans adorned places of worship with raisins, and raisins were awarded as prizes in sporting events. Today’s chief raisin producers include Turkey and the United States, which together account for about 80 percent of the world’s raisin production. Other important raisin-producing countries include Iran, Greece, Chile, and South Africa. The U.S. raisin industry is located mainly in California, where the first raisin grapes were planted in 1851.

The most important varieties of raisin grapes are the Thompson Seedless, a pale yellow seedless grape also known as Sultanina (California); Muscat, or Alexandria, a large-seeded variety also known as Gordo Blanco (Australia); White Hanepoot (South Africa); and the Black Corinth, a small black seedless type, also called Zante currant, Staphis (Greece), and panariti. Other varieties of raisins of local importance include the Round Kishmish, Rosaki, Dattier, Monukka, and Cape Currant.

Raisins also may be designated by the method of drying (natural, golden-bleached, lexia), the form in which marketed (seeded, loose, layers), the principal place of origin (Aíyion, Smyrna, Málaga), the size grades, or the quality grades. Natural raisins are dried in the sun in their natural condition; they are grayish black or grayish brown, with the natural bloom intact and a rather tough skin. Golden-bleached raisins are produced from Thompson Seedless grapes dipped in 0.5 percent lye and exposed to sulfur dioxide after drying. They are lemon-yellow to golden yellow in colour and are used chiefly in baked goods. Sulfur-bleached raisins are pretreated the same as golden-bleached, put on trays, and left in the sun for three to four hours. The trays are then stacked, and the drying is continued for several weeks in the shade. The finished product appears waxy and creamy and faintly reddish yellow in colour.

Soda-dipped or soda-bleached raisins derive from Thompson Seedless grapes hot-dipped in dilute lye but not sulfured, then dried in the sun or in a dehydrator. If dried rapidly, they are light amber to medium brown, moderately tender, and mild-flavoured. Oil-dipped raisins and lexias are dipped in a dilute solution of lye upon which a thin film of olive oil is floated; they are dried on trays in direct sunlight and are medium to dark brown, tender, and mild in flavour. Raisins provide an excellent source of iron for the diet.

Details

A raisin is a dried grape. Raisins are produced in many regions of the world and may be eaten raw or used in cooking, baking, and brewing. In the United Kingdom, Ireland, New Zealand, Australia and South Africa, the word raisin is reserved for the dark-colored dried large grape, with sultana being a golden-colored dried grape, and currant being a dried small Black Corinth seedless grape.

Etymology

The word "raisin" dates back to Middle English and is a loanword from Old French; in modern French, raisin means "grape", while a dried grape is a raisin sec, or "dry grape". The Old French word, in turn, developed from the Latin word racemus, "a bunch of grapes."

Varieties

Raisin varieties depend on the type of grape and appear in a variety of sizes and colors including green, black, brown, purple, blue, and yellow. Seedless varieties include the sultana (the common American type is known as Thompson Seedless in the United States), the Zante currants (black Corinthian raisins, Vitis vinifera L. var. Apyrena) and Flame grapes. Raisins are traditionally sun-dried, but may also be artificially dehydrated.

"Golden raisins" are generally dried in dehydrators with controlled temperature and humidity, which allows them to retain a lighter color and more moisture. They are often treated with sulfur dioxide after drying.

Black Corinth or Zante currants are small, sometimes seedless raisins that are much darker and have a tart, tangy flavor. They are usually called currants. Muscat raisins are large compared to other varieties, and also sweeter.

Grapes used to produce raisins in the Middle East and Asia include the large black monukka (or manucca) grapes that produce large raisins.

Processing

Raisins are produced commercially by drying harvested grape berries. For a grape berry to dry, water inside the grape must be removed completely from the interior of the cells onto the surface of the grape where the water droplets can evaporate. However, this diffusion process is very difficult because the grape skin contains wax in its cuticle, which prevents the water from passing through. In addition to this, the physical and chemical mechanisms located on the outer layers of the grape are adapted to prevent water loss. The three steps to commercial raisin production include pre-treatment, drying, and post-drying processes.

Pre-treatment

Pre-treatment is a necessary step in raisin production to ensure the increased rate of water removal during the drying process. A faster water removal rate decreases the rate of browning and helps to produce more desirable raisins. The historical method of completing this process was developed in the Mediterranean and Asia Minor areas by using a dry emulsion cold dip made of potassium carbonate and ethyl esters of fatty acids. This dip was shown to increase the rate of water loss by two- to three-fold.

Recently, new methods have been developed such as exposing the grapes to oil emulsions or dilute alkaline solutions. These methods can encourage water transfer to the outer surface of grapes which helps to increase the efficiency of the drying process.

Drying

The three types of drying methods are: sun drying, shade drying, and mechanical drying. Sun drying is an inexpensive process; however, environmental contamination, insect infections, and microbial deterioration can occur and the resulting raisins are often of low quality. Additionally, sun drying is a slow process and may not produce the most desirable raisins.

Mechanical drying can be done in a safer and more controlled environment where rapid drying is guaranteed. One type of mechanical drying is to use microwave drying. Water molecules in the grapes absorb microwave energy resulting in rapid evaporation. Microwave drying produces puffed raisins.

Post-drying processes

After the drying process is complete, raisins are sent to processing plants where they are cleaned with water to remove any foreign objects that may have become embedded during the drying process. Stems and off-grade raisins are also removed. The washing process may cause rehydration, so another drying step is completed after washing to ensure that the added moisture has been removed.

All steps in the production of raisins are very important in determining the quality of raisins. Sometimes, sulfur dioxide is applied to raisins after the pre-treatment step and before drying to decrease the rate of browning caused by the reaction between polyphenol oxidase and phenolic compounds. Sulfur dioxide also helps to preserve flavor and prevent the loss of certain vitamins during the drying process.

Production

Global production of raisins in 2020-21 was 1.2 million tonnes, led by Turkey, the United States, Iran, and India as the largest producers.

Nutrition

Raisins are 15% water, 79% carbohydrates (including 4% fiber), 3% protein, and contain negligible fat. In a reference amount of 100 grams (3.5 oz), raisins supply 299 kilocalories and moderate amounts (10–19% DV) of the Daily Value for several dietary minerals, riboflavin, and vitamin B6.

Toxicity in animals

Raisins can cause kidney failure in both cats and dogs. The cause of this is not known.

Additional Information

A raisin is a dehydrated or sun-dried grape. Raisins are sweet and chewy, and they're often found in oatmeal cookies and granola.

Raisins are one of the most common kind of dried fruit — they turn up everywhere from a preschooler's snack box to a fancy bakery's scones and cinnamon rolls. The most common way to make a raisin is to dry grapes in the sun, though it's quicker for producers to use dehydrating machines. The word raisin dates to the thirteenth century, from the Latin racemus, which means "cluster of grapes or berries."

In general, and when people consume them in moderation, raisins are a healthful, tasty food to add to the diet. Raisins are a good source of essential nutrients, minerals, and energy in the form of calories and sugars.

Raisins themselves make a quick and simple snack throughout the day. People can use them as a topping for yogurt or cereals, and they can also include them in many other products, such as baked goods, trail mix, and granola.

In general, and when people consume them in moderation, raisins are a healthful, tasty food to add to the diet. Raisins are a good source of essential nutrients, minerals, and energy in the form of calories and sugars.

Raisins themselves make a quick and simple snack throughout the day. People can use them as a topping for yogurt or cereals, and they can also include them in many other products, such as baked goods, trail mix, and granola.

Benefits

Raisins can aid digestion and fight cancer cells.
Raisins can be a helpful and beneficial addition to the diet.

Aid in digestion

Raisins may be a simple way to help keep the digestive system healthy. Raisins contain helpful soluble fibers, which give body to the stool and help it pass through the intestines easier. This may help improve digestion and promote regularity.

Prevent anemia

Raisins may play a part in preventing anemia. They contain good amounts of iron, copper, and vitamins that are essential for making red blood cells and carrying oxygen throughout the body.

Prevent too much acidity

Raisins contain substantial amounts of beneficial minerals, such as iron, copper, magnesium, and potassium. These are alkaline, or basic, minerals on the pH scale and may help balance acidity levels in the stomach.

Lower risk of heart disease risk factors

A study posted to Postgraduate Medicine noted that regularly eating raisins may help reduce cardiovascular risk factors, such as blood pressure rate, when compared to other snacks. This is because raisins are a low sodium food that also contains a good source of potassium, which helps the blood vessels relax.

Fight against cancer cells

Raisins are also a good source of antioxidant compounds.

Dietary antioxidants are essential, as they may protect the body from oxidative damage and free radicals. Oxidative damage and free radicals are risk factors in many types of cancer, tumor growth, and aging.

Protect eye health

Raisins contain polyphenols, which are antioxidants that may protect the cells in the eyes from free radical damage. This may in turn help protect the eyes from eye disorders, such as age-related macular degeneration and cataracts.

Improve skin health

Antioxidants may help keep the skin cells young and prevent damage from aging cells. Raisins also contain valuable nutrients, such as vitamin C, selenium, and zinc. This combination of nutrients and antioxidants may be a helpful addition to a diet that focuses on creating good skin health.

Lower blood sugar

The Postgraduate Medicine study also noted that compared to eating other snacks, regularly eating raisins may help lower a person’s blood sugar. Even though raisins contain a more concentrated amount of sugars than fresh fruit, raisin intake compared to processed snacks decreased hemoglobin a1c, which is a marker of blood sugar management.

This means that a serving of raisins may be an excellent way to satisfy a sweet craving.

Jai Ganesh · 2024-08-07 16:52:54

2248) Triple Point

Gist

Triple Point : The temperature and pressure at which a substance can exist in equilibrium in the liquid, solid, and gaseous states. The triple point of pure water is at 0.01°C (273.16K, 32.01°F) and 4.58 mm (611.2Pa) of mercury and is used to calibrate thermometers.

Summary

In chemistry and physics, the triple point is the temperature and pressure at which solid, liquid, and vapor phases of a particular substance coexist in equilibrium. It is a specific case of thermodynamic phase equilibrium. The term "triple point" was coined by James Thomson in 1873.

Example

The triple point for water is at 0.01 degree Celsius at 4.56 mm Hg. The triple point of water is a fixed quantity, used to define other triple point values and the kelvin unit of temperature. Note the triple point may include more than one solid phase if a specific substance has polymorphs.

The three-phase equilibrium lines meet at one point. This triple point is the point where the temperature and pressure conditions are right for all three states (solid, liquid and gas) to exist together at equilibrium. The triple point is like the peak of a pyramid.

The triple point of a substance is the temperature and pressure at which the three phases (gas, liquid, and solid) of that substance coexist in thermodynamic equilibrium. The triple point of water is used to define the Kelvin(K), the base unit of thermodynamic temperature in the International System of Units (SI).

Details

In thermodynamics, the triple point of a substance is the temperature and pressure at which the three phases (gas, liquid, and solid) of that substance coexist in thermodynamic equilibrium. It is that temperature and pressure at which the sublimation, fusion, and vaporisation curves meet. For example, the triple point of mercury occurs at a temperature of −38.8 °C (−37.8 °F) and a pressure of 0.165 mPa.

In addition to the triple point for solid, liquid, and gas phases, a triple point may involve more than one solid phase, for substances with multiple polymorphs. Helium-4 is unusual in that it has no sublimation/deposition curve and therefore no triple points where its solid phase meets its gas phase. Instead, it has a vapor-liquid-superfluid point, a solid-liquid-superfluid point, a solid-solid-liquid point, and a solid-solid-superfluid point. None of these should be confused with the Lambda Point, which is not any kind of triple point.

The term "triple point" was coined in 1873 by James Thomson, brother of Lord Kelvin. The triple points of several substances are used to define points in the ITS-90 international temperature scale, ranging from the triple point of hydrogen (13.8033 K) to the triple point of water (273.16 K, 0.01 °C, or 32.018 °F).

Before 2019, the triple point of water was used to define the kelvin, the base unit of thermodynamic temperature in the International System of Units (SI). The kelvin was defined so that the triple point of water is exactly 273.16 K, but that changed with the 2019 redefinition of SI base units, where the kelvin was redefined so that the Boltzmann constant is exactly

, and the triple point of water became an experimentally measured constant.

Triple point of water:

Gas–liquid–solid triple point

Following the 2019 redefinition of the SI base units, the value of the triple point of water is no longer used as a defining point. However, its empirical value remains important: the unique combination of pressure and temperature at which liquid water, solid ice, and water vapor coexist in a stable equilibrium is approximately 273.16±0.0001 K and a vapor pressure of 611.657 pascals (6.11657 mbar; 0.00603659 atm).

Liquid water can only exist at pressures equal to or greater than the triple point. Below this, in the vacuum of outer space, solid ice sublimates, transitioning directly into water vapor when heated at a constant pressure. Conversely, above the triple point, solid ice first melts into liquid water upon heating at a constant pressure, then evaporates or boils to form vapor at a higher temperature.

For most substances, the gas–liquid–solid triple point is the minimum temperature where the liquid can exist. For water, this is not the case. The melting point of ordinary ice decreases with pressure, as shown by the phase diagram's dashed green line. Just below the triple point, compression at a constant temperature transforms water vapor first to solid and then to liquid.

Historically, during the Mariner 9 mission to Mars, the triple point pressure of water was used to define "sea level." Now, laser altimetry and gravitational measurements are preferred to define Martian elevation.

High-pressure phases

At high pressures, water has a complex phase diagram with 15 known phases of ice and several triple points, including 10 whose coordinates are shown in the diagram. For example, the triple point at 251 K (-22 °C) and 210 MPa (2070 atm) corresponds to the conditions for the coexistence of ice Ih (ordinary ice), ice III and liquid water, all at equilibrium. There are also triple points for the coexistence of three solid phases, for example ice II, ice V and ice VI at 218 K (-55 °C) and 620 MPa (6120 atm).

For those high-pressure forms of ice which can exist in equilibrium with liquid, the diagram shows that melting points increase with pressure. At temperatures above 273 K (0 °C), increasing the pressure on water vapor results first in liquid water and then a high-pressure form of ice. In the range 251-273 K, ice I is formed first, followed by liquid water and then ice III or ice V, followed by other still denser high-pressure forms.

Triple-point cells

Triple-point cells are used in the calibration of thermometers. For exacting work, triple-point cells are typically filled with a highly pure chemical substance such as hydrogen, argon, mercury, or water (depending on the desired temperature). The purity of these substances can be such that only one part in a million is a contaminant, called "six nines" because it is 99.9999% pure. A specific isotopic composition (for water, VSMOW) is used because variations in isotopic composition cause small changes in the triple point. Triple-point cells are so effective at achieving highly precise, reproducible temperatures, that an international calibration standard for thermometers called ITS–90 relies upon triple-point cells of hydrogen, neon, oxygen, argon, mercury, and water for delineating six of its defined temperature points. (VSMOW is Vienna Standard Mean Ocean Water).

Additional Information

A triple point is a specific temperature and pressure where 3 phases (solid, liquid, gas) coexist in equilibrium. Eutectic point is a specific composition of two components where the melting point is the lowest you can get with those two components. Generally pure substance have higher melting point than mixture but the eutectic point is the composition that has the lowest melting point.

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Jai Ganesh · 2024-08-08 00:05:16

2249) International Organization for Standardization

Gist

The International Organization for Standardization (ISO) is an international nongovernmental organization made up of national standards bodies that develops and publishes a wide range of proprietary, industrial, and commercial standards.

Summary

International Organization for Standardization (ISO), specialized international organization concerned with standardization in all technical and nontechnical fields except electrical and electronic engineering (the responsibility of the International Electrotechnical Commission [IEC]). Founded in Geneva in 1947, its membership extends to more than 160 countries. Each member is the national body “most representative of standardization in its country”; in Western industrial countries this is usually a private organization, such as the American National Standards Institute (ANSI) and the British Standards Institution (BSI), but in most other countries it is a governmental organization.

Standardization affects units of measurement; alphabetization and transliteration; specifications for parts, materials, surfaces, processes, tools, methods of testing, and machines; and even the form in which specifications are presented. ISO standards cover a variety of sectors, ranging from food safety to manufacturing to technology. Such standards help to facilitate international trade by establishing quality and other criteria between countries and to protect consumers by ensuring that products and services are certified to meet international minimums. In addition, ISO standards enable the entry of firms into new markets, both locally and internationally, by facilitating the direct comparison of products across markets. Upon request, the ISO establishes international technical committees to investigate and resolve specific issues of standardization. Because of technological evolution, ISO standards are optimally reviewed for possible revision every five years.

Details

The International Organization for Standardization is an independent, non-governmental, international standard development organization composed of representatives from the national standards organizations of member countries. Membership requirements are given in Article 3 of the ISO Statutes.

ISO was founded on 23 February 1947, and (as of July 2024) it has published over 25,000 international standards covering almost all aspects of technology and manufacturing. It has over 800 technical committees (TCs) and subcommittees (SCs) to take care of standards development.

The organization develops and publishes international standards for easeness on end-user or commoners market, like availablity in technical and nontechnical fields, including everything from manufactured products and technology to food safety, transport, IT, agriculture, and healthcare. More specialized topics like electrical and electronic engineering are instead handled by the International Electrotechnical Commission. It is headquartered in Geneva, Switzerland. The three official languages of ISO are English, French, and Russian.

Name and abbreviations

The International Organization for Standardization in French is Organisation internationale de normalisation and in Russian, (Mezhdunarodnaya organizatsiya po standartizatsii).

Although one might think ISO is an abbreviation for "International Standardization Organization" or a similar title in another language, the letters do not officially represent an acronym or initialism. The organization provides this explanation of the name:

Because 'International Organization for Standardization' would have different acronyms in different languages (IOS in English, OIN in French), our founders decided to give it the short form ISO. ISO is derived from the Greek word isos (ίσος, meaning "equal"). Whatever the country, whatever the language, the short form of our name is always ISO.

During the founding meetings of the new organization, however, the Greek word explanation was not invoked, so this meaning may be a false etymology.

Both the name ISO and the ISO logo are registered trademarks and their use is restricted.

History

The organization that is known today as ISO began in 1926 as the International Federation of the National Standardizing Associations (ISA), which primarily focused on mechanical engineering. The ISA was suspended in 1942 during World War II but, after the war, the ISA was approached by the recently-formed United Nations Standards Coordinating Committee (UNSCC) with a proposal to form a new global standards body.

In October 1946, ISA and UNSCC delegates from 25 countries met in London and agreed to join forces to create the International Organization for Standardization. The organization officially began operations on 23 February 1947.

ISO Standards were originally known as ISO Recommendations (ISO/R), e.g., "ISO 1" was issued in 1951 as "ISO/R 1".

Structure and organization

ISO is a voluntary organization whose members are recognized authorities on standards, each one representing one country. Members meet annually at a General Assembly to discuss the strategic objectives of ISO. The organization is coordinated by a central secretariat based in Geneva.

A council with a rotating membership of 20 member bodies provides guidance and governance, including setting the annual budget of the central secretariat.

The technical management board is responsible for more than 250 technical committees, who develop the ISO standards.

Joint technical committee with IEC

ISO has a joint technical committee (JTC) with the International Electrotechnical Commission (IEC) to develop standards relating to information technology (IT). Known as JTC 1 and entitled "Information technology", it was created in 1987 and its mission is "to develop worldwide Information and Communication Technology (ICT) standards for business and consumer applications."

There was previously also a JTC 2 that was created in 2009 for a joint project to establish common terminology for "standardization in the field of energy efficiency and renewable energy sources". It was later disbanded.

Membership

As of 2022, there are 167 national members representing ISO in their country, with each country having only one member;

ISO has three membership categories,

* Member bodies are national bodies considered the most representative standards body in each country. These are the only members of ISO that have voting rights.
* Correspondent members are countries that do not have their own standards organization. These members are informed about the work of ISO, but do not participate in standards promulgation.
* Subscriber members are countries with small economies. They pay reduced membership fees, but can follow the development of standards.

Participating members are called "P" members, as opposed to observing members, who are called "O" members.

Financing

ISO is funded by a combination of:

* Organizations that manage the specific projects or loan experts to participate in the technical work
* Subscriptions from member bodies, whose subscriptions are in proportion to each country's gross national product and trade figures
* Sale of standards

Additional Information

The International Organization for Standardization (ISO) is an international nongovernmental organization made up of national standards bodies. The ISO develops and publishes a wide range of proprietary, industrial, and commercial standards and is comprised of representatives from various national standards organizations.

Key Takeaways

* The International Organization for Standardization (ISO) is an international nongovernmental organization made up of national standards bodies that develops and publishes a wide range of proprietary, industrial, and commercial standards.
* The International Organization for Standardization (ISO) was founded in 1947 and is headquartered in Geneva, Switzerland.
* In addition to producing standards, ISO also publishes technical reports, technical specifications, publicly available specifications, technical corrigenda, and guides.
* The ISO plays an important role in facilitating world trade by providing common standards among different countries.
* ISO standards cover all fields, from healthcare to technology to manufacturing to security to the environment.
Understanding the International Organization for Standardization (ISO)

The International Organization for Standardization was founded in 1947 and is headquartered in Geneva, Switzerland. The organization began in the 1920s as the International Federation of the National Standardizing Associations (ISA). After being suspended during World War II, the United Nations Standards Coordinating Committee (UNSCC) proposed a new global standards body, and the International Organization for Standardization was formed.

The ISO works in 167 countries. Members of the organization are the foremost standards organizations in their countries; there is only one member per country. While individuals and companies cannot become members of ISO, there are various ways that industry experts can collaborate with the ISO.

Members of ISO meet annually at a General Assembly to discuss the strategic objectives of the organization. In addition, there is a 20-person council with rotating membership that provides guidance and governance for the organization.

Meaning of ISO

The organization's abbreviated name - ISO - is not an acronym; it derives from the ancient Greek word ísos, meaning equal or equivalent. Because the organization would have different acronyms in different languages, the founders of the organization decided to call it by the short form ISO.

Activities of the International Organization for Standardization (ISO)

ISO develops and publishes standards for a vast range of products, materials, and processes. Currently, the organization has over 24,362 standards, which are included in the ISO Standards catalog, which is broken down into various segments, such as healthcare technology, railway engineering, jewelry, clothing, metallurgy, weapons, paint, civil engineering, agriculture, and aircraft. In addition to producing standards, ISO also publishes technical reports, technical specifications, publicly available specifications, technical corrigenda, and guides.

The ISO plays an important role in facilitating world trade by providing common standards among different countries. These standards are intended to ensure that products and services are safe, reliable, and of good quality.

For the end-user and consumer, these standards ensure that certified products conform to the minimum standards set internationally.

In some cases, "ISO" is used to describe the product that conforms to an ISO standard as a result of the ubiquity of these standards. For example, the speed of film, or the sensitivity of a photographic film to light, is referred to by its ISO number (ISO 6, ISO 2240, and ISO 5800).

Jai Ganesh · 2024-08-08 19:28:01

2250) Wildlife

Gist

What is wildlife and its importance?

A group of local or native animals is referred to as wildlife. Importance of wildlife: It balances nature's elements and the preservation of food chains. Wildlife provides a large gene pool.

Wildlife refers to undomesticated animal species, but has come to include all organisms that grow or live wild in an area without being introduced by humans. Wildlife was also synonymous to game: those birds and mammals that were hunted for sport. Wildlife can be found in all ecosystems.

Wildlife means undomesticated animal species. All living things which are neither human nor domesticated, especially mammals, birds, and fishes, are known as wildlife.

Summary

Nature reserve, area set aside for the purpose of preserving certain animals, plants, or both. A nature reserve differs from a national park usually in being smaller and having as its sole purpose the protection of nature.

Endangered species are often kept in reserves, away from the hunters who brought them close to extinction. In the United States, numerous wildlife refuges have served this purpose, especially with respect to birds. Nature reserves are also numerous in Europe, India, Indonesia, and some African countries.

The origin of modern nature reserves lies in medieval times, when landowners established game preserves for the protection of animals that they hunted. The idea of protecting animals simply to keep them from dying out did not arise until the 19th century.

National forest, in the United States, any of numerous forest areas set aside under federal supervision for the purposes of conserving water, timber, wildlife, fish, and other renewable resources and providing recreational areas for the public. The national forests are administered by the Forest Service in the Department of Agriculture. They numbered 156 by the 21st century and occupy a total area of almost 300,000 square miles (about 770,000 square km) in 40 states and Puerto Rico. They are managed according to the principle of multiple use, whereby various resources—including water, timber, and grasslands—are utilized to serve the nation’s interests without reducing the land’s capability to produce more.

The U.S. national forests began in 1891 as a system of forest reserves, the establishment of which had been urged by Secretary of the Interior Carl Schurz. President Theodore Roosevelt created the Forest Service in 1905 and established additional forest reserves. In 1907 the forest reserves were renamed national forests.

Details

Wildlife refers to undomesticated animal species, but has come to include all organisms that grow or live wild in an area without being introduced by humans. Wildlife was also synonymous to game: those birds and mammals that were hunted for sport. Wildlife can be found in all ecosystems. Deserts, plains, grasslands, woodlands, forests, and other areas including the most developed urban areas, all have distinct forms of wildlife. While the term in popular culture usually refers to animals that are untouched by human factors, most scientists agree that much wildlife is affected by human activities. Some wildlife threaten human safety, health, property and quality of life. However, many wild animals, even the dangerous ones, have value to human beings. This value might be economic, educational, or emotional in nature.

Humans have historically tended to separate civilization from wildlife in a number of ways, including the legal, social and moral senses. Some animals, however, have adapted to suburban environments. This includes such animals as feral cats, dogs, mice, and rats. Some religions declare certain animals to be sacred, and in modern times, concern for the natural environment has provoked activists to protest against the exploitation of wildlife for human benefit or entertainment.

Global wildlife populations have decreased by 68% since 1970 as a result of human activity, particularly overconsumption, population growth, and intensive farming, according to a 2020 World Wildlife Fund's Living Planet Report and the Zoological Society of London's Living Planet Index measure, which is further evidence that humans have unleashed a sixth mass extinction event. According to CITES, it has been estimated that annually the international wildlife trade amounts to billions of dollars and it affects hundreds of millions of animal and plant specimen.

Interactions with humans:

Trade

Wildlife trade refers to the products that are derived from non-domesticated animals or plants usually extracted from their natural environment or raised under controlled conditions. It can involve the trade of living or dead individuals, tissues such as skins, bones or meat, or other products. Legal wildlife trade is regulated by the United Nations' Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), which currently has 184 member countries called Parties. Illegal wildlife trade is widespread and constitutes one of the major illegal economic activities, comparable to the traffic of drugs and weapons.

Wildlife trade is a serious conservation problem, has a negative effect on the viability of many wildlife populations and is one of the major threats to the survival of vertebrate species. The illegal wildlife trade has been linked to the emergence and spread of new infectious diseases in humans, including emergent viruses. Global initiative like the United Nations Sustainable Development Goal 15 have a target to end the illegal supply of wildlife.

For food

Stone Age people and hunter-gatherers relied on wildlife, both plants and animals, for their food. In fact, some species may have been hunted to extinction by early human hunters. Today, hunting, fishing, and gathering wildlife is still a significant food source in some parts of the world. In other areas, hunting and non-commercial fishing are mainly seen as a sport or recreation. Meat sourced from wildlife that is not traditionally regarded as game is known as bushmeat. The increasing demand for wildlife as a source of traditional food in East Asia is decimating populations of sharks, primates, pangolins and other animals, which they believe have aphrodisiac properties.
Malaysia is home to a vast array of amazing wildlife. However, illegal hunting and trade poses a threat to Malaysia's natural diversity.

— Chris S. Shepherd

A November 2008 report from biologist and author Sally Kneidel, PhD, documented numerous wildlife species for sale in informal markets along the Amazon River, including wild-caught marmosets sold for as little as $1.60 (5 Peruvian soles). Many Amazon species, including peccaries, agoutis, turtles, turtle eggs, anacondas, armadillos are sold primarily as food.

Media

Wildlife has long been a common subject for educational television shows. National Geographic Society specials appeared on CBS since 1965, later moving to American Broadcasting Company and then Public Broadcasting Service. In 1963, NBC debuted Wild Kingdom, a popular program featuring zoologist Marlin Perkins as host. The BBC natural history unit in the United Kingdom was a similar pioneer, the first wildlife series LOOK presented by Sir Peter Scott, was a studio-based show, with filmed inserts. David Attenborough first made his appearance in this series, which was followed by the series Zoo Quest during which he and cameraman Charles Lagus went to many exotic places looking for and filming elusive wildlife—notably the Komodo dragon in Indonesia and lemurs in Madagascar. Since 1984, the Discovery Channel and its spinoff Animal Planet in the US have dominated the market for shows about wildlife on cable television, while on Public Broadcasting Service the NATURE strand made by WNET-13 in New York and NOVA by WGBH in Boston are notable. Wildlife television is now a multimillion-dollar industry with specialist documentary film-makers in many countries including UK, US, New Zealand, Australia, Austria, Germany, Japan, and Canada. There are many magazines and websites which cover wildlife including National Wildlife Magazine, Birds & Blooms, Birding (magazine), wildlife.net and Ranger Rick for children.

Tourism

Wildlife tourism is an element of many nations' travel industry centered around observation and interaction with local animal and plant life in their natural habitats. While it can include eco- and animal-friendly tourism, safari hunting and similar high-intervention activities also fall under the umbrella of wildlife tourism. Wildlife tourism, in its simplest sense, is interacting with wild animals in their natural habitat, either actively (e.g. hunting/collection) or passively (e.g. watching/photography). Wildlife tourism is an important part of the tourism industries in many countries including many African and South American countries, Australia, India, Canada, Indonesia, Bangladesh, Malaysia, Sri Lanka and Maldives among many. It has experienced a dramatic and rapid growth in recent years worldwide and many elements are closely aligned to eco-tourism and sustainable tourism.

According to United Nations World Tourism Organization, with an annual growth about 3%, 7% of world tourism industry relates to wildlife tourism. They also estimate that the growth is much more significant in places like UNESCO World Heritage Sites. Wildlife tourism currently employs 22 million people worldwide directly or indirectly, and contributes more than $ 120 billion to global GDP. As a multimillion-dollar international industry, wildlife tourism is often characterized by the offering of customized tour packages and safaris to allow close access to wildlife.

Suffering

Wild animal suffering is the suffering experienced by non-human animals living outside of direct human control due to harms, such as disease, injury, parasitism, starvation and malnutrition, dehydration, weather conditions, natural disasters, and killings by other animals, as well as psychological stress. Some estimates indicate that these individual animals make up the vast majority of animals in existence. An extensive amount of natural suffering has been described as an unavoidable consequence of Darwinian evolution, as well as the pervasiveness of reproductive strategies, which favor producing large numbers of offspring, with a low amount of parental care and of which only a small number survive to adulthood, the rest dying in painful ways, has led some to argue that suffering dominates happiness in nature.

The topic has historically been discussed in the context of the philosophy of religion as an instance of the problem of evil. More recently, starting in the 19th century, a number of writers have considered the subject from a secular standpoint as a general moral issue, that humans might be able to help prevent. There is considerable disagreement around taking such action, as many believe that human interventions in nature should not take place because of practicality, valuing ecological preservation over the well-being and interests of individual animals, considering any obligation to reduce wild animal suffering implied by animal rights to be absurd, or viewing nature as an idyllic place where happiness is widespread. Some have argued that such interventions would be an example of human hubris, or playing God, and use examples of how human interventions, for other reasons, have unintentionally caused harm. Others, including animal rights writers, have defended variants of a laissez-faire position, which argues that humans should not harm wild animals but that humans should not intervene to reduce natural harms that they experience.

Advocates of such interventions argue that animal rights and welfare positions imply an obligation to help animals suffering in the wild due to natural processes. Some have asserted that refusing to help animals in situations where humans would consider it wrong not to help humans is an example of speciesism. Others argue that humans intervene in nature constantly—sometimes in very substantial ways—for their own interests and to further environmentalist goals. Human responsibility for enhancing existing natural harms has also been cited as a reason for intervention. Some advocates argue that humans already successfully help animals in the wild, such as vaccinating and healing injured and sick animals, rescuing animals in fires and other natural disasters, feeding hungry animals, providing thirsty animals with water, and caring for orphaned animals. They also assert that although wide-scale interventions may not be possible with our current level of understanding, they could become feasible in the future with improved knowledge and technologies. For these reasons, they argue it is important to raise awareness about the issue of wild animal suffering, spread the idea that humans should help animals suffering in these situations, and encourage research into effective measures, which can be taken in the future to reduce the suffering of these individuals, without causing greater harms.

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Jai Ganesh · 2024-08-09 16:17:47

2251) Synthetic Diamonds

Gist

Synthetic diamonds are sometimes referred to as carbon made diamonds - but the reality is, both natural and lab diamonds are made from carbon. With their identical internal structure and physical optics, the only way to tell a lab diamond from a natural diamond is with specialist equipment.

Summary

Synthetic diamond, man-made diamond that is usually produced by subjecting graphite to very high temperatures and pressures. Synthetic diamond resembles natural diamond in most fundamental properties, retaining the extreme hardness, broad transparency (when pure), high thermal conductivity, and high electrical resistivity for which diamond is highly prized. Because synthesis is an expensive process, large stones of gem quality are rarely made. Instead, most synthetic diamond is produced as grit or small crystals that are used to provide hard coatings for industrial equipment such as grinding wheels, machine tools, wire-drawing dies, quarrying saws, and mining drills. In addition, diamond films can be grown on various materials by subjecting carbon-containing gas to extreme heat, and those layers can be used in cutting tools, windows for optical devices, or substrates for semiconductors.

In 1880 the Scottish chemist James Ballantyne Hannay claimed that he had made diamonds by heating a mixture of paraffin, bone oil, and lithium to red heat in sealed wrought-iron tubes. In 1893 the French chemist Henri Moissan announced he had been successful in making diamonds by placing a crucible containing pure carbon and iron in an electric furnace and subjecting the very hot (about 4,000 °C [7,000 °F]) mixture to great pressure by sudden cooling in a water bath. Neither of those experiments has been repeated successfully.

During the first half of the 20th century, the American physicist Percy Williams Bridgman conducted extensive studies of materials subjected to high pressures. His work led to the synthesis by the General Electric Company, Schenectady, New York, of diamonds in its laboratory in 1955. The stones were made by subjecting graphite to pressures approaching 7 gigapascals (1 million pounds per square inch) and to temperatures above 1,700 °C (3,100 °F) in the presence of a metal catalyst. Tons of diamonds of industrial quality have been made in variations of that process every year since 1960.

Details

Laboratory-grown (LGD), also called lab-grown diamond, laboratory-created, man-made, artisan-created, artificial, synthetic, or cultured diamond, is diamond that is produced in a controlled technological process (in contrast to naturally formed diamond, which is created through geological processes and obtained by mining). Unlike diamond simulants (imitations of diamond made of superficially similar non-diamond materials), synthetic diamonds are composed of the same material as naturally formed diamonds—pure carbon crystallized in an isotropic 3D form—and share identical chemical and physical properties. As of 2023 the heaviest synthetic diamond ever made weighs 30.18 ct (6.0 g), and the heaviest natural diamond ever found weighs 3167 ct (633.4 g).

Numerous claims of diamond synthesis were reported between 1879 and 1928; most of these attempts were carefully analyzed but none was confirmed. In the 1940s, systematic research of diamond creation began in the United States, Sweden and the Soviet Union, which culminated in the first reproducible synthesis in 1953. Further research activity yielded the discoveries of high pressure high temperature diamond (HPHT) and CVD diamond, named for their production method (high-pressure high-temperature and chemical vapor deposition, respectively). These two processes still dominate synthetic diamond production. A third method in which nanometer-sized diamond grains are created in a detonation of carbon-containing explosives, known as detonation synthesis, entered the market in the late 1990s. A fourth method, treating graphite with high-power ultrasound, has been demonstrated in the laboratory, but as of 2008 had no commercial application.

(CVD stands for Chemical Vapour Deposition, and is the commonly used name for diamonds grown in a laboratory via a process of chemical vapour deposition.)

The properties of synthetic diamonds depend on the manufacturing process. Some have properties such as hardness, thermal conductivity and electron mobility that are superior to those of most naturally formed diamonds. Synthetic diamond is widely used in abrasives, in cutting and polishing tools and in heat sinks. Electronic applications of synthetic diamond are being developed, including high-power switches at power stations, high-frequency field-effect transistors and light-emitting diodes. Synthetic diamond detectors of ultraviolet (UV) light or high-energy particles are used at high-energy research facilities and are available commercially. Due to its unique combination of thermal and chemical stability, low thermal expansion and high optical transparency in a wide spectral range, synthetic diamond is becoming the most popular material for optical windows in high-power CO
2 lasers and gyrotrons. It is estimated that 98% of industrial-grade diamond demand is supplied with synthetic diamonds.

Both CVD and HPHT diamonds can be cut into gems and various colors can be produced: clear white, yellow, brown, blue, green and orange. The advent of synthetic gems on the market created major concerns in the diamond trading business, as a result of which special spectroscopic devices and techniques have been developed to distinguish synthetic and natural diamonds.

History

In the early stages of diamond synthesis, the founding figure of modern chemistry, Antoine Lavoisier, played a significant role. His groundbreaking discovery that a diamond's crystal lattice is similar to carbon's crystal structure paved the way for initial attempts to produce diamonds. After it was discovered that diamond was pure carbon in 1797, many attempts were made to convert various cheap forms of carbon into diamond. The earliest successes were reported by James Ballantyne Hannay in 1879 and by Ferdinand Frédéric Henri Moissan in 1893. Their method involved heating charcoal at up to 3,500 °C (6,330 °F) with iron inside a carbon crucible in a furnace. Whereas Hannay used a flame-heated tube, Moissan applied his newly developed electric arc furnace, in which an electric arc was struck between carbon rods inside blocks of lime. The molten iron was then rapidly cooled by immersion in water. The contraction generated by the cooling supposedly produced the high pressure required to transform graphite into diamond. Moissan published his work in a series of articles in the 1890s.

Many other scientists tried to replicate his experiments. Sir William Crookes claimed success in 1909. Otto Ruff claimed in 1917 to have produced diamonds up to 7 mm (0.28 in) in diameter, but later retracted his statement. In 1926, Dr. J. Willard Hershey of McPherson College replicated Moissan's and Ruff's experiments, producing a synthetic diamond. Despite the claims of Moissan, Ruff, and Hershey, other experimenters were unable to reproduce their synthesis.

The most definitive replication attempts were performed by Sir Charles Algernon Parsons. A prominent scientist and engineer known for his invention of the steam turbine, he spent about 40 years (1882–1922) and a considerable part of his fortune trying to reproduce the experiments of Moissan and Hannay, but also adapted processes of his own. Parsons was known for his painstakingly accurate approach and methodical record keeping; all his resulting samples were preserved for further analysis by an independent party. He wrote a number of articles—some of the earliest on HPHT diamond—in which he claimed to have produced small diamonds. However, in 1928, he authorized Dr. C. H. Desch to publish an article in which he stated his belief that no synthetic diamonds (including those of Moissan and others) had been produced up to that date. He suggested that most diamonds that had been produced up to that point were likely synthetic spinel.

ASEA

The first known (but initially not reported) diamond synthesis was achieved on February 16, 1953, in Stockholm by ASEA (Allmänna Svenska Elektriska Aktiebolaget), Sweden's major electrical equipment manufacturing company. Starting in 1942, ASEA employed a team of five scientists and engineers as part of a top-secret diamond-making project code-named QUINTUS. The team used a bulky split-sphere apparatus designed by Baltzar von Platen and Anders Kämpe. Pressure was maintained within the device at an estimated 8.4 GPa (1,220,000 psi) and a temperature of 2,400 °C (4,350 °F) for an hour. A few small diamonds were produced, but not of gem quality or size.

Due to questions on the patent process and the reasonable belief that no other serious diamond synthesis research occurred globally, the board of ASEA opted against publicity and patent applications. Thus the announcement of the ASEA results occurred shortly after the GE press conference of February 15, 1955.

GE diamond project

In 1941, an agreement was made between the General Electric (GE), Norton and Carborundum companies to further develop diamond synthesis. They were able to heat carbon to about 3,000 °C (5,430 °F) under a pressure of 3.5 gigapascals (510,000 psi) for a few seconds. Soon thereafter, the Second World War interrupted the project. It was resumed in 1951 at the Schenectady Laboratories of GE, and a high-pressure diamond group was formed with Francis P. Bundy and H. M. Strong. Tracy Hall and others joined the project later.

The Schenectady group improved on the anvils designed by Percy Bridgman, who received a Nobel Prize in Physics for his work in 1946. Bundy and Strong made the first improvements, then more were made by Hall. The GE team used tungsten carbide anvils within a hydraulic press to squeeze the carbonaceous sample held in a catlinite container, the finished grit being squeezed out of the container into a gasket. The team recorded diamond synthesis on one occasion, but the experiment could not be reproduced because of uncertain synthesis conditions, and the diamond was later shown to have been a natural diamond used as a seed.

Hall achieved the first commercially successful synthesis of diamond on December 16, 1954, and this was announced on February 15, 1955. His breakthrough came when he used a press with a hardened steel toroidal "belt" strained to its elastic limit wrapped around the sample, producing pressures above 10 GPa (1,500,000 psi) and temperatures above 2,000 °C (3,630 °F). The press used a pyrophyllite container in which graphite was dissolved within molten nickel, cobalt or iron. Those metals acted as a "solvent-catalyst", which both dissolved carbon and accelerated its conversion into diamond. The largest diamond he produced was 0.15 mm (0.0059 in) across; it was too small and visually imperfect for jewelry, but usable in industrial abrasives. Hall's co-workers were able to replicate his work, and the discovery was published in the major journal Nature. He was the first person to grow a synthetic diamond with a reproducible, verifiable and well-documented process. He left GE in 1955, and three years later developed a new apparatus for the synthesis of diamond—a tetrahedral press with four anvils—to avoid violating a U.S. Department of Commerce secrecy order on the GE patent applications.

Further development

Synthetic gem-quality diamond crystals were first produced in 1970 by GE, then reported in 1971. The first successes used a pyrophyllite tube seeded at each end with thin pieces of diamond. The graphite feed material was placed in the center and the metal solvent (nickel) between the graphite and the seeds. The container was heated and the pressure was raised to about 5.5 GPa (800,000 psi). The crystals grow as they flow from the center to the ends of the tube, and extending the length of the process produces larger crystals. Initially, a week-long growth process produced gem-quality stones of around 5 mm (0.20 in) (1 carat or 0.2 g), and the process conditions had to be as stable as possible. The graphite feed was soon replaced by diamond grit because that allowed much better control of the shape of the final crystal.

The first gem-quality stones were always yellow to brown in color because of contamination with nitrogen. Inclusions were common, especially "plate-like" ones from the nickel. Removing all nitrogen from the process by adding aluminum or titanium produced colorless "white" stones, and removing the nitrogen and adding boron produced blue ones. Removing nitrogen also slowed the growth process and reduced the crystalline quality, so the process was normally run with nitrogen present.

Although the GE stones and natural diamonds were chemically identical, their physical properties were not the same. The colorless stones produced strong fluorescence and phosphorescence under short-wavelength ultraviolet light, but were inert under long-wave UV. Among natural diamonds, only the rarer blue gems exhibit these properties. Unlike natural diamonds, all the GE stones showed strong yellow fluorescence under X-rays. The De Beers Diamond Research Laboratory has grown stones of up to 25 carats (5.0 g) for research purposes. Stable HPHT conditions were kept for six weeks to grow high-quality diamonds of this size. For economic reasons, the growth of most synthetic diamonds is terminated when they reach a mass of 1 carat (200 mg) to 1.5 carats (300 mg).

In the 1950s, research started in the Soviet Union and the US on the growth of diamond by pyrolysis of hydrocarbon gases at the relatively low temperature of 800 °C (1,470 °F). This low-pressure process is known as chemical vapor deposition (CVD). William G. Eversole reportedly achieved vapor deposition of diamond over diamond substrate in 1953, but it was not reported until 1962. Diamond film deposition was independently reproduced by Angus and coworkers in 1968 and by Deryagin and Fedoseev in 1970. Whereas Eversole and Angus used large, expensive, single-crystal diamonds as substrates, Deryagin and Fedoseev succeeded in making diamond films on non-diamond materials (silicon and metals), which led to massive research on inexpensive diamond coatings in the 1980s.

From 2013, reports emerged of a rise in undisclosed synthetic melee diamonds (small round diamonds typically used to frame a central diamond or embellish a band) being found in set jewelry and within diamond parcels sold in the trade. Due to the relatively low cost of diamond melee, as well as relative lack of universal knowledge for identifying large quantities of melee efficiently, not all dealers have made an effort to test diamond melee to correctly identify whether it is of natural or synthetic origin. However, international laboratories are now beginning to tackle the issue head-on, with significant improvements in synthetic melee identification being made.

Additional Information

Synthetic diamond has been recognized as an extremely attractive material for both (bio-) chemical sensing and as an interface to biological systems. Synthetic diamond have outstanding electrochemical properties, superior chemical inertness and biocompatibility. Recent advances in the synthesis of highly conducting nanocrystalline-diamond thin films and nano wires have lead to an entirely new class of electrochemical biosensors and bio-inorganic interfaces. In addition, it also combines with development of new chemical approaches to covalently attach biomolecules on the diamond surface also contributed to the advancement of diamond-based biosensors. The feasibility of a capacitive field-effect EDIS (electrolyte-diamond-insulator-semiconductor) platform for multi-parameter sensing is demonstrated with an O-terminated nanocrystalline-diamond (NCD) film as transducer material for the detection of pH and penicillin concentration. This has also been extended for the label-free electrical monitoring of adsorption and binding of charged macromolecules. One more recent study demonstrated a novel bio-sensing platform, which is introduced by combination of a) geometrically controlled DNA bonding using vertically aligned diamond nano-wires and b) the superior electrochemical sensing properties of diamond as transducer material. Diamond nano-wires can be a new approach towards next generation electrochemical gene sensor platforms.

Jai Ganesh · 2024-08-10 15:55:24

2252) Waterborne Disease

Gist

What are the 7 waterborne diseases?

Causes of Waterborne Illness

* Cryptosporidiosis (Cryptosporidium)
* Cyclosporiasis (Cyclospora spp.)
* Escherichia coli O157:H7 Infection (E. ...
* Giardiasis (Giardia)
* Harmful Algal Blooms (HABs)
* Hot Tub Rash (Pseudomonas Dermatitis/Folliculitis)
* Legionellosis (Legionella)
* Naegleria fowleri and Primary Amebic Meningoencephalitis.

Summary

Waterborne diseases are those diseases that are transmitted by ingestion of contaminated water (WHO, 2012).

WHO, 2012. Disease information. World Health Organization (WHO). Accessed 19 September 2020.

Additional scientific description

Important waterborne diseases include diarrhoeal diseases, cholera, shigella, typhoid, hepatitis A and E, and poliomyelitis (WHO, 2012).

Diarrhoea occurs worldwide and causes 4% of all deaths and 5% of health loss to various forms of disability or loss of function. It is most commonly caused by gastrointestinal infections which kill around 2.2 million people globally each year, mostly children in developing countries. Use of water in hygiene is an important preventive measure but contaminated water is also an important cause of diarrhoea. Cholera and dysentery cause severe, sometimes life-threatening forms of diarrhoea (WHO, 2016a).

Diarrhoea is the passage of loose or liquid stools more frequently than is normal for the individual. It is primarily a symptom of gastrointestinal infection. Depending on the type of infection, the diarrhoea may be watery (for example in cholera) or passed with blood (in dysentery, for example). Diarrhoea due to infection may last a few days, or several weeks, as in persistent diarrhoea. Severe diarrhoea may be life-threatening due to fluid loss in watery diarrhoea, particularly in infants and young children, the malnourished and people with impaired immunity. The impact of repeated or persistent diarrhoea on nutrition and the effect of malnutrition on susceptibility to infectious diarrhoea can be linked in a vicious cycle among children, especially in developing countries. Diarrhoea is also associated with other infections such as malaria and measles. Chemical irritation of the gut or non-infectious bowel disease can also result in diarrhoea (WHO, 2016a).

Diarrhoea is a symptom of infection caused by a host of bacterial, viral and parasitic organisms most of which can be spread by contaminated water. It is more common when there is a shortage of clean water for drinking, cooking and cleaning and basic hygiene is important in prevention. Water contaminated with human faeces, for example, from municipal sewage, septic tanks and latrines is of special concern. Animal faeces also contain microorganisms that can cause diarrhoea. Diarrhoea can also spread from person to person, aggravated by poor personal hygiene. Food is another major cause of diarrhoea when it is prepared or stored in unhygienic conditions. Water can contaminate food during irrigation, and fish and seafood from polluted water may also contribute to the disease (WHO, 2016).

The infectious agents that cause diarrhoea are present or are sporadically introduced throughout the world. Diarrhoea is a rare occurrence for most people who live in developed countries where sanitation is widely available, access to safe water is high and personal and domestic hygiene is relatively good. Worldwide around 1.1 billion people lack access to improved water sources and 2.4 billion have no basic sanitation. Diarrhoea due to infection is widespread throughout the developing world. In Southeast Asia and Africa, diarrhoea is responsible for as much as 8.5% and 7.7% of all deaths, respectively (WHO, 2016a).

Details

Waterborne diseases are conditions (meaning adverse effects on human health, such as death, disability, illness or disorders) caused by pathogenic micro-organisms that are transmitted by water. These diseases can be spread while bathing, washing, drinking water, or by eating food exposed to contaminated water. They are a pressing issue in rural areas amongst developing countries all over the world. While diarrhea and vomiting are the most commonly reported symptoms of waterborne illness, other symptoms can include skin, ear, respiratory, or eye problems. Lack of clean water supply, sanitation and hygiene (WASH) are major causes for the spread of waterborne diseases in a community. Therefore, reliable access to clean drinking water and sanitation is the main method to prevent waterborne diseases.

Microorganisms causing diseases that characteristically are waterborne prominently include protozoa and bacteria, many of which are intestinal parasites, or invade the tissues or circulatory system through walls of the digestive tract. Various other waterborne diseases are caused by viruses.

Yet other important classes of waterborne diseases are caused by metazoan parasites. Typical examples include certain Nematoda, that is to say "roundworms". As an example of waterborne Nematode infections, one important waterborne nematode disease is Dracunculiasis. It is acquired by swallowing water in which certain copepoda occur that act as vectors for the Nematoda. Anyone swallowing a copepod that happens to be infected with Nematode larvae in the genus Dracunculus, becomes liable to infection. The larvae cause guinea worm disease.

Another class of waterborne metazoan pathogens are certain members of the Schistosomatidae, a family of blood flukes. They usually infect people that make skin contact with the water. Blood flukes are pathogens that cause Schistosomiasis of various forms, more or less seriously affecting hundreds of millions of people worldwide.

Terminology

The term waterborne disease is reserved largely for infections that predominantly are transmitted through contact with or consumption of microbially polluted water. Many infections may be transmitted by microbes or parasites that accidentally, possibly as a result of exceptional circumstances, have entered the water. However, the fact that there might be an occasional infection need not mean that it is useful to categorize the resulting disease as "waterborne". Nor is it common practice to refer to diseases such as malaria as "waterborne" just because mosquitoes have aquatic phases in their life cycles, or because treating the water they inhabit happens to be an effective strategy in control of the mosquitoes that are the vectors.

A related term is "water-related disease" which is defined as "any significant or widespread adverse effects on human health, such as death, disability, illness or disorders, caused directly or indirectly by the condition, or changes in the quantity or quality of any water". Water-related diseases are grouped according to their transmission mechanism: water borne, water hygiene, water based, water related. The main transmission mode for waterborne diseases is ingestion of contaminated water.

Causes

Lack of clean water supply, sanitation and hygiene (WASH) are major causes for the spread of waterborne diseases in a community. The fecal–oral route is a disease transmission pathway for waterborne diseases. Poverty also increases the risk of communities to be affected by waterborne diseases. For example, the economic level of a community impacts their ability to have access to clean water. Less developed countries might be more at risk for potential outbreaks of waterborne diseases but more developed regions also are at risk to waterborne disease outbreaks.

Influence of climate change

Global climate change has increased the occurrence of some infectious diseases. Infectious diseases whose transmission is impacted by climate change include, for example, vector-borne diseases like dengue fever, malaria, tick-borne diseases, leishmaniasis, zika fever, chikungunya and Ebola. One mechanism contributing to increased disease transmission is that climate change is altering the geographic range and seasonality of the insects (or disease vectors) that can carry the diseases. Scientists stated a clear observation in 2022: "The occurrence of climate-related food-borne and waterborne diseases has increased (very high confidence)."

Infectious diseases that are sensitive to climate can be grouped into: vector-borne diseases (transmitted via mosquitos, ticks etc.), waterborne diseases (transmitted via viruses or bacteria through water), and food-borne diseases.(spread through pathogens via food). Climate change affects the distribution of these diseases due to the expanding geographic range and seasonality of these diseases and their vectors. Like other ways climate change affects human health, climate change exacerbates existing inequalities and challenges in managing infectious disease.

Additional Information

Each year, waterborne diseases afflict hundreds of millions of people, primarily those living without safe, accessible water in developing countries.

Of the seven most common waterborne diseases in the world, diarrhea is the central symptom. The latest research shows that diarrhea is the second leading cause of death for children under the age of five, causing more childhood deaths than malaria, AIDS, and measles combined.

That’s hundreds of thousands of deaths, but there is hope for the future. Experts believe we can end the global water and sanitation crisis in our lifetime.

What are Waterborne Diseases?

Waterborne diseases are illnesses caused by microscopic organisms, like viruses and bacteria, that are ingested through contaminated water or by coming in contact with feces.

If every person on the planet was able to practice safe sanitation and hygiene and have access to clean water, these diseases would not exist. Governments, NGOs, and communities themselves have made great strides in the past 20 years to end waterborne diseases. Still, there is much to be done.

Learn about seven waterborne diseases and help prevent them today.

1. Typhoid Fever

Although rare in industrialized countries, typhoid fever is well-known in extremely poor parts of developing nations; it’s estimated that up to 20 million people worldwide suffer from the illness each year. It’s spread through contaminated food, unsafe water, and poor sanitation, and it is highly contagious.

Symptoms include:

A fever that increases gradually
Muscle aches
Fatigue
Sweating
Diarrhea or constipation
Prevention and Treatment

Vaccines are recommended for people who are traveling in areas where poor sanitation and unsafe water are common. The vaccine can be injected via a shot or taken orally for a number of days. To prevent it, refrain from drinking any water that isn’t bottled and sealed, and do not eat food from villages or street vendors. Typhoid is treated with antibiotics.

2. Cholera

Cholera is commonly found in humanitarian emergencies or marginalized villages where poverty and poor sanitation are rampant. The disease is spread through contaminated water and causes severe dehydration and diarrhea. Cholera can be fatal within days or even hours of exposure to the bacteria, but only 1 in 10 people will develop life-threatening symptoms.

Symptoms include:

Nausea
Vomiting
Diarrhea
Muscle cramps
Prevention and Treatment

Cholera is a waterborne illness that’s easily prevented when traveling. Wash your hands often, only eat foods that are completely cooked and hot (no sushi), and only eat vegetables you can peel yourself, like avocados, bananas, and oranges. Of course, drink safe water.

Washing hands in Africa to limit the spread of disease and viruses

When handwashing in unavailable, cholera can impact an entire village. In developing countries like Ethiopia, data shows that 40 percent of households do not have means to wash their hands properly, meaning they don’t have safe water, soap, and a facility to wash. This makes hygiene management and disease prevention nearly impossible for these communities.

3. Giardia

This waterborne disease is shared through contaminated water, most often in ponds and streams, but it can also be found in a town’s water supply, swimming pools, and more. The infection is caused by a parasite and typically clears up after a few weeks. However, it’s possible for those who have been exposed will experience intestinal problems for years to come.

Symptoms include:

Abdominal pain
Cramps and bloating
Diarrhea
Nausea
Weight loss
Prevention and Treatment

While there is no vaccine for giardia, there are simple ways to avoid the infection. Wash your hands with soap often, don’t swallow water while swimming, and drink only bottled water.

With time, the immune system will typically beat giardia on its own. But, if symptoms worsen, doctors prescribe anti-parasite and antibiotic medications.

Water-poor communities cannot protect themselves from illnesses like giardia, and treatment for this illness can come at a high cost for a family living in poverty.

When families learn how to construct their own handwashing facilities, bathrooms, and dish drying racks, they take control of their health.

4. Dysentery

An intestinal infection, dysentery is a waterborne disease characterized by severe diarrhea as well as blood or mucus in the stool. Dysentery is good reason to always wash your hands, as the disease is spread mainly through poor hygiene. It can be caused by bacteria, viruses, or parasites in unsafe food and water and by people coming in contact with fecal matter. If someone experiencing dysentery cannot replace fluids quickly enough, their life could be at risk.

Symptoms include:

Stomach cramps and pain
Diarrhea
Fever
Nausea
Vomiting
Dehydration
Prevention and Treatment

To prevent dysentery, wash your hands with soap frequently, order all drinks without ice, don’t eat food sold by street vendors, and only eat fruits you can peel. Drink only sealed, bottled water while traveling in places with higher dysentery risk, such as communities where proper hygiene practices are uncommon.

Mild dysentery usually clears up with rest and fluids, but over-the-counter medications such as Pepto-Bismol can help with stomach cramping. More severe cases can be treated with antibiotics, although some strains of the disease are resistant.

5. Escherichia Coli (E. coli)

E. coli is a bacteria with various strains, some dangerous and some beneficial. For example, E. coli bacteria is important in creating a healthy intestinal tract.

However, if animal waste has found its way into farmland where produce is grown or if strains of E. coli are spread through the process of making ground beef, those who consume these foods could experience symptoms of the waterborne illness. The bacteria is also found in unsafe water sources around the globe where human water sources and cattle coexist.

Symptoms of dangerous strains of E. coli are similar to that of dysentery and other waterborne diseases. Most bouts of E. coli pass within a week, but older people and young children have a greater chance of developing life-threatening symptoms. Anyone believed to have been exposed to contaminated food or water should contact a doctor if diarrhea contains blood.

Prevention and Treatment

As always, avoid water possibly contaminated by human and/or animal feces (like ponds, rivers, and swamps). If you are going to eat ground beef, cook thoroughly. Wash fruits and vegetables well, wash hands often, and drink only safe water.

To treat the disease, drink plenty of safe water, rest, and take over-the-counter diarrheal medication.

While these are simple prevention and treatment tips, there are many remote communities in Uganda who have no choice but to drink from swamps.

6. Hepatitis A

Hepatitis A is a liver infection caused by consuming contaminated food and water or by coming in close contact with someone who has the infection. People who travel in developing countries often or work in rural communities with poor sanitation and hygiene management are most exposed to the disease.

Symptoms include:

Fatigue
Clay-colored bowel movements
Jaundice
Nausea and vomiting
Abdominal pain, especially near your liver
Loss of appetite
Sudden fever

The infection usually goes away in a few weeks, but it’s possible that it can become severe and last several months.

Prevention and Treatment

The best way to prevent hepatitis A is by getting the vaccine. Eat only foods that are thoroughly cooked and served hot, and avoid eating anything at room temperature. Only eat fruit that you can peel and that you have peeled yourself. Don’t eat from food vendors and don’t eat runny eggs or raw/rare meat. For a full list of dos and don’ts, visit the CDC’s page on Hepatitis A here.

Once a person has hepatitis A, they build an immunity and will likely never get it again. However, the symptoms are serious, often forcing people to take time off work or school to recover. If you have contracted hepatitis A, rest, avoid drinking alcohol, and drink plenty of fluids. The disease will run its course, and full recovery is expected after three months.

7. Salmonella

Most cases of salmonella come from ingesting food or water contaminated with feces. Undercooked meat, egg products, fruits, and vegetables can also carry the disease. Most people don’t develop complications, but children, pregnant women, older adults, and people with weakened immune systems are most at risk.

Symptoms include:

Blood in stool
Chills
Headache
Diarrhea

Prevention and Treatment

When preparing your own food, make sure to cook thoroughly and store or freeze within 30 minutes of use. Avoid touching birds or reptiles, and as always, wash your hands frequently.

Salmonella infection dehydrates the body. Treat it by drinking fluids and electrolytes. More serious infections can require hospitalization and antibiotics.

Over and over again, cholera is prevented and typhoid eradicated. Children no longer battle waterborne illness, and parents go back to work.

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