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Selective Inverted Sink
The selective inverted sink or SIS is a device used by farmers to protect plants from frost, developed by Uruguayan Rafael Guarga in the late 1990s. The sink is actually a large fan housed in a chimney-like structure, and works by defeating surface temperature inversion. Cold air is denser than warm air, and will pool at ground level during calm weather. This lowers the surface temperature, even if the ambient temperature Colloquially, "room temperature" is a range of air temperatures that most people prefer for indoor settings. It feels comfortable to a person when they are wearing typical indoor clothing. Human comfort can extend beyond this range depending on ... is higher. Vents near the base of the chimney allow cold surface air to be pulled up through the chimney, creating a suction effect that draws warmer air down to surface level. The SIS is more efficient than typical ground-heaters, and is widely used to combat frost. ReferencesTo blow up or down? Inverted sin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Farmer
A farmer is a person engaged in agriculture, raising living organisms for food or raw materials. The term usually applies to people who do some combination of raising field crops, orchards, vineyards, poultry, or other livestock. A farmer might own the farm land or might work as a laborer on land owned by others. In most developed economies, a "farmer" is usually a farm owner ( landowner), while employees of the farm are known as ''farm workers'' (or farmhands). However, in other older definitions a farmer was a person who promotes or improves the growth of plants, land or crops or raises animals (as livestock or fish) by labor and attention. Over half a billion farmers are smallholders, most of whom are in developing countries, and who economically support almost two billion people. Globally, women constitute more than 40% of agricultural employees. History Farming dates back as far as the Neolithic, being one of the defining characteristics of that era. By the Bronze ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frost
Frost is a thin layer of ice on a solid surface, which forms from water vapor in an above-freezing atmosphere coming in contact with a solid surface whose temperature is below freezing, and resulting in a phase change from water vapor (a gas) to ice (a solid) as the water vapor reaches the freezing point. In temperate climates, it most commonly appears on surfaces near the ground as fragile white crystals; in cold climates, it occurs in a greater variety of forms. The propagation of crystal formation occurs by the process of nucleation. The ice crystals of frost form as the result of fractal process development. The depth of frost crystals varies depending on the amount of time they have been accumulating, and the concentration of the water vapor (humidity). Frost crystals may be invisible (black), clear (translucent), or white; if a mass of frost crystals scatters light in all directions, the coating of frost appears white. Types of frost include crystalline frost ( h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uruguay
Uruguay (; ), officially the Oriental Republic of Uruguay ( es, República Oriental del Uruguay), is a country in South America. It shares borders with Argentina to its west and southwest and Brazil to its north and northeast; while bordering the Río de la Plata to the south and the Atlantic Ocean to the southeast. It is part of the Southern Cone region of South America. Uruguay covers an area of approximately and has a population of an estimated 3.4 million, of whom around 2 million live in the metropolitan area of its capital and largest city, Montevideo. The area that became Uruguay was first inhabited by groups of hunter–gatherers 13,000 years ago. The predominant tribe at the moment of the arrival of Europeans was the Charrúa people, when the Portuguese first established Colónia do Sacramento in 1680; Uruguay was colonized by Europeans late relative to neighboring countries. The Spanish founded Montevideo as a military stronghold in the early 18th centur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rafael Guarga
Rafael Andrés Guarga Ferro (born 23 August 1940 in Montevideo) is a Uruguayan industrial engineer and inventor. Career After graduating from the University of the Republic, Guarga had to leave his country due to the civic-military dictatorship. He pursued his career in Mexico, obtaining a doctorate at the National Autonomous University of Mexico. Back in Uruguay he devoted himself to lecturing; in 1992-1998 he served as Dean of the School of Engineering, and in 1998-2006 as Rector of the university. In the late 1990s Guarga invented the selective inverted sink (acronym SIS), a device used by farmers to protect plants from frost. Last access: 19 April 2010 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
