porous

SpongeBob is an anthropomorphic, yellow, porous, sponge with a face. He has disproportionally thin and short extremities extending from his body (arms and legs), and resembles a kitchen sponge more than a sea sponge. SpongeBob has the ability to transform into other shapes at will, absorb physical blows as well as large amounts of water, and reassemble pieces which fall off of him. His arms can become variable in length and shape at will, are retractable, and can be re-grown at will. He has six long black wiry eyelashes, and his eyes have sk ...

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SpongeBob SquarePants character, SpongeBob SquarePants character - Appearance, SpongeBob SquarePants character - General, SpongeBob SquarePants character - Job and Leisure, SpongeBob SquarePants character - Family, SpongeBob SquarePants character - Trivia

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River - The world's ten longest rivers. It is difficult to measure the length of a river, mainly because rivers have a fractal property, which means that the more precise the measure, the longer the river will seem. Also, it's hard to state exactly where a river begins or ends, as very often, upstream, rivers are formed by seasonal streams, swamps, or changing lakes. This is an average measurement. Nile (6,690 km) Amazon (6,452km) Yangtze (Chang Jiang) (6,380 km) Mis ...

See also:

River, River - Topography, River - Biology, River - Pollution, River - Navigation, River - Dams, River - Flooding, River - Logjams, River - Management, River - River lists, River - The world's ten longest rivers, River - Well-known rivers in alphabetic order, River - Other lists, River - Rivers in myth and fiction, River - Real rivers, River - Mythological rivers, River - Fictional rivers, River - Crossings, River - Transport

Read more here: » River: Encyclopedia II - River - River lists

Bhutan's economy is one of the world's smallest and least developed, and is based on agriculture, forestry, and the sale of hydroelectric power to India. Agriculture provides the main livelihood for more than 90% of the population. Agrarian practices consist largely of subsistence farming and animal husbandry. Handicrafts are a small cottage industry and a source of income for many. The sculpting of religious figurines is a popular occupation, and gilded Buddha statues and Buddhist saints are sold to tourists. A landscape that varies from hi ...

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Bhutan, Bhutan - The Name, Bhutan - History, Bhutan - Geography, Bhutan - Economy, Bhutan - Government and politics, Bhutan - Districts, Bhutan - Military and foreign affairs, Bhutan - Demographics, Bhutan - The Nepali minority and human rights issues, Bhutan - Language, Bhutan - Culture, Bhutan - Notes

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The northern region consists of an arc of glaciated mountain peaks with an extremely cold climate at the highest elevations. Most peaks in the north are over 7,000 m above sea level; the highest point is claimed to be the Kula Kangri, at 7,553 m, but detailed topographic studies claim Kula Kangri is wholly in Tibet and modern Chinese measurements claim that Gangkhar Puensum, which has the distinction of being the highest unclimbed mountain in the world, is higher at 7,570m. Watered by snow-fed rivers, alpine valleys in this region ...

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Bhutan, Bhutan - The Name, Bhutan - History, Bhutan - Geography, Bhutan - Economy, Bhutan - Government and politics, Bhutan - Districts, Bhutan - Military and foreign affairs, Bhutan - Demographics, Bhutan - The Nepali minority and human rights issues, Bhutan - Language, Bhutan - Culture, Bhutan - Notes

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The Hubbert peak theory, also known as peak oil, is a theory concerning the long-term rate of production of conventional oil and other fossil fuels. It assumes that oil reserves are not replenishable (i.e. that abiogenic replenishment is negligible), and predicts that future world oil production must inevitably reach a peak and then decline as these reserves are exhausted. Controversy surrounds the theory, as predictions for when the global peak will act ...

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Petroleum, Petroleum - Origin, Petroleum - Biogenic theory, Petroleum - Abiogenic theory, Petroleum - Extraction, Petroleum - Alternate means of producing oil, Petroleum - History, Petroleum - Environmental effects, Petroleum - Future of oil, Petroleum - Classification, Petroleum - Pricing, Petroleum - Top petroleum-producing countries, Petroleum - Petroleum in Military Strategy, Petroleum - Books about the petroleum industry, Petroleum - Films about petroleum, Petroleum - Writers covering the petroleum industry

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The first oil wells were drilled in China in the 4th century or earlier. They had depth of up to 800 feet and were drilled using bits attached to bamboo poles. The oil was burned to evaporate brine and produce salt. By the 10th century, extensive bamboo pipelines connected oil wells with salt springs. Ancient Persian tablets indicate the medicinal and lighting uses of petroleum in the upper echelons of their society. In the 8th century, the streets of the newly-constructed Baghdad were paved with tar, derived from easily-accessible pe ...

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Petroleum, Petroleum - Origin, Petroleum - Biogenic theory, Petroleum - Abiogenic theory, Petroleum - Extraction, Petroleum - Alternate means of producing oil, Petroleum - History, Petroleum - Environmental effects, Petroleum - Future of oil, Petroleum - Classification, Petroleum - Pricing, Petroleum - Top petroleum-producing countries, Petroleum - Petroleum in Military Strategy, Petroleum - Books about the petroleum industry, Petroleum - Films about petroleum, Petroleum - Writers covering the petroleum industry

Read more here: » Petroleum: Encyclopedia II - Petroleum - History

Generally the first stage in the extraction of crude oil is to drill a well into the underground reservoir. Historically, in the USA some oil fields existed where the oil rose naturally to the surface, but most of these fields have long since been depleted, except for certain remote locations in Alaska. Often many wells (called multilateral wells) will be drilled into the same reservoir, to ensure that the extraction rate will be economically viable. Also, some wells (secondary wells) may be used to pump water, steam, acids or various gas mixtures into the reservoir to raise or maintain the reservoir pressure, and ...

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Petroleum, Petroleum - Origin, Petroleum - Biogenic theory, Petroleum - Abiogenic theory, Petroleum - Extraction, Petroleum - Alternate means of producing oil, Petroleum - History, Petroleum - Environmental effects, Petroleum - Future of oil, Petroleum - Classification, Petroleum - Pricing, Petroleum - Top petroleum-producing countries, Petroleum - Petroleum in Military Strategy, Petroleum - Books about the petroleum industry, Petroleum - Films about petroleum, Petroleum - Writers covering the petroleum industry

Read more here: » Petroleum: Encyclopedia II - Petroleum - Extraction

The oil industry classifies "crude" by the location of its origin (e.g., "West Texas Intermediate, WTI" or "Brent") and often by its relative weight (API gravity) or viscosity ("light", "intermediate" or "heavy"); refiners may also refer to it as "sweet", which means it contains relatively little sulfur, or as "sour", which means it contains substantial amounts of sulfur and requires more refining in o ...

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Petroleum, Petroleum - Origin, Petroleum - Biogenic theory, Petroleum - Abiogenic theory, Petroleum - Extraction, Petroleum - Alternate means of producing oil, Petroleum - History, Petroleum - Environmental effects, Petroleum - Future of oil, Petroleum - Classification, Petroleum - Pricing, Petroleum - Top petroleum-producing countries, Petroleum - Petroleum in Military Strategy, Petroleum - Books about the petroleum industry, Petroleum - Films about petroleum, Petroleum - Writers covering the petroleum industry

Read more here: » Petroleum: Encyclopedia II - Petroleum - Classification

References to the oil price are usually either references to the spot price of either WTI/Light Crude as traded on New York Mercantile Exchange (NYMEX) for delivery in Cushing, Oklahoma; or the price of Brent as traded on the International Petroleum Exchange (IPE) for delivery at Sullom Voe. The price of a barrel of oil is highly dependent on both its grade (which is determined by factors such as its specific gravity or API and its sulphur content) and location. The vast majority of oil will not be traded on an exchange but on a over-the-cou ...

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Petroleum, Petroleum - Origin, Petroleum - Biogenic theory, Petroleum - Abiogenic theory, Petroleum - Extraction, Petroleum - Alternate means of producing oil, Petroleum - History, Petroleum - Environmental effects, Petroleum - Future of oil, Petroleum - Classification, Petroleum - Pricing, Petroleum - Top petroleum-producing countries, Petroleum - Petroleum in Military Strategy, Petroleum - Books about the petroleum industry, Petroleum - Films about petroleum, Petroleum - Writers covering the petroleum industry

Read more here: » Petroleum: Encyclopedia II - Petroleum - Pricing

The origins of the name Bhutan are unclear; historians have suggested that it may have originated in variations of the Sanskrit words Bhota-ant (the end of Bhot – a variation of the Indian Sanskrit word "Buddha" meaning enlightened, another word for Tibet), or Bhu-uttan (highlands). The word Bhutan as a name for the country dates from the late 19th century. The Dzongkha (and Tibetan) name for the country is D ...

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Bhutan, Bhutan - The Name, Bhutan - History, Bhutan - Geography, Bhutan - Economy, Bhutan - Government and politics, Bhutan - Districts, Bhutan - Military and foreign affairs, Bhutan - Demographics, Bhutan - The Nepali minority and human rights issues, Bhutan - Language, Bhutan - Culture, Bhutan - Notes

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Fick's First Law is used in steady state diffusion, i.e., when the concentration within the diffusion volume does not change with respect to time (Jin=Jout). Where J is the diffusion flux in dimensions of [parts length-2 time-1], [mol m-2 s-1] D is the diffusion coefficient or diffusivity in dimensions of [length2 time-1], [m2See also:

Fick's law of diffusion, Fick's law of diffusion - History, Fick's law of diffusion - Fick's First Law, Fick's law of diffusion - Fick's Second Law, Fick's law of diffusion - Applicability, Fick's law of diffusion - Temperature dependence of the Diffusion coefficient, Fick's law of diffusion - A Biological Perspective, Fick's law of diffusion - External link

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Source: Energy Statistics from the U.S. Government (Ordered by amount (MMbbl/d = millions of barrels per day) produced in 2004): Saudi Arabia (OPEC) - 10.37 MMbbl/d Russia - 9.27 MMbbl/d United States 1 - 8.69 MMbbl/d Iran (OPEC) - 4.09 MMbbl/d Mexico 1 - 3.83 MMbbl/d China 1 - 3.62 MMbbl/d Norway 1 - 3.18 MMbbl/d Canada 1 - 3.14 MMbbl/d Venezuela (OPEC) 1 - 2.86 MMbbl/d

Sedimentary rocks are economically important in that they can be used as construction material. In addition, sedimentary rocks often form porous and permeable reservoirs in sedimentary basins in which petroleum and other hydrocarbons can be found. It is believed that the relatively low levels of carbon dioxide in the Earth's atmosphere, in comparison to that of Venus, is due to large amounts of carbon being trapped in limestone and dolomite sedimentary layers. The flux of carbon from eroded sedi ...

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Sedimentary rock, Sedimentary rock - Formation, Sedimentary rock - Classification, Sedimentary rock - Clastic sedimentary rocks, Sedimentary rock - Biogenic sedimentary rocks, Sedimentary rock - Precipitate sedimentary rocks, Sedimentary rock - Other information

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The soil profile of chalk downland in England is a thin soil overlaying the parent chalk. Weathering of the chalk has created a characteristic soil known as rendzina. Unlike many soils in which there are easily distinguished layers or horizons, a chalk rendzina soil consists of only a shallow dark humus rich surface layer which grades through a lighter brown hillwash containing small pellets of chalk, to the white of the chalk itself. This is largely because of the purity of the chalk which is here about 98% calcium carbonate and the consequent absence of soil-building clay minerals which ar ...

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Downland, Downland - Formation of downland, Downland - Hydrology, Downland - Downland soil, Downland - Downland habitat, Downland - Examples of downland, Downland - The Southern England Chalk Formation, Downland - United States

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River - The world's ten longest rivers. It is difficult to measure the length of a river, mainly because rivers have a fractal property, which means that the more precise the measure, the longer the river will seem. Also, it's hard to state exactly where a river begins or ends, as very often, upstream, rivers are formed by seasonal streams, swamps, or changing lakes. This is an average measurement. Nile (6,690 km) Amazon (6,400 km) Yangtze (Chang Jiang) (6,380 km) Mi ...

See also:

River, River - Topography, River - Biology, River - Pollution, River - Navigation, River - Dams, River - Flooding, River - Logjams, River - Management, River - River lists, River - The world's ten longest rivers, River - Well-known rivers in alphabetic order, River - Other lists, River - Rivers in myth and fiction, River - Real rivers, River - Mythological rivers, River - Fictional rivers, River - Crossings, River - Transport

Read more here: » River: Encyclopedia II - River - River lists

In its natural state a river may be inconvenient to man in a variety of ways. Rivers in inhabited areas have therefore been managed or controlled to make them more useful and less disruptive to human activity. The river channel may be dredged to make it deeper for navigation or to prevent flooding. Dams (see above) or weirs may be built to control the flow, store water, or extract energy. Levees may be built to prevent flooding. Sluice gates provide a means of controlling flow and adjusting river level ...

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River, River - Topography, River - Biology, River - Pollution, River - Navigation, River - Dams, River - Flooding, River - Logjams, River - Management, River - River lists, River - The world's ten longest rivers, River - Well-known rivers in alphabetic order, River - Other lists, River - Rivers in myth and fiction, River - Real rivers, River - Mythological rivers, River - Fictional rivers, River - Crossings, River - Transport

Read more here: » River: Encyclopedia II - River - Management

Flooding is a natural part of a river's cycles. Human activity, however, has upset the natural way flooding occurs by walling off rivers and straightening their courses. Removal of bogs, swamps and other wetlands in order to produce farmland has reduced the absorption zones for excess water and made floods into sudden disasters rather than gradual increases in water flow. In ancient Egypt, life was made possible through the floods of the Nile and the accompanying silt and sediment which enriched the fields with fresh nutrients. Nowadays, since people have built on these floodplains, floods are disasters, causi ...

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River, River - Topography, River - Biology, River - Pollution, River - Navigation, River - Dams, River - Flooding, River - Logjams, River - Management, River - River lists, River - The world's ten longest rivers, River - Well-known rivers in alphabetic order, River - Other lists, River - Rivers in myth and fiction, River - Real rivers, River - Mythological rivers, River - Fictional rivers, River - Crossings, River - Transport

Read more here: » River: Encyclopedia II - River - Flooding

River - Real rivers. The Thames in Edward Rutherfurd's London. The Thames in Jerome K. Jerome's Three Men in a Boat. The Thames and the Congo in Joseph Conrad's Heart of Darkness. The Mississippi in Mark Twain's Huckleberry Finn. The River Liffey through Dublin in James Joyce's Finnegans Wake. River - Mythological rivers. In Greek mythology, the Acheron, Cocytus, Phlegethon, Lethe and Styx (the f ...

See also:

River, River - Topography, River - Biology, River - Pollution, River - Navigation, River - Dams, River - Flooding, River - Logjams, River - Management, River - River lists, River - The world's ten longest rivers, River - Well-known rivers in alphabetic order, River - Other lists, River - Rivers in myth and fiction, River - Real rivers, River - Mythological rivers, River - Fictional rivers, River - Crossings, River - Transport

Read more here: » River: Encyclopedia II - River - Rivers in myth and fiction

Aerogel is composed of 99.8% air with a typical density of 3 mg/cm3. It feels like hard foam. Pressing softly won't leave any mark; pressing harder will leave a permanent dimple. Pressing hard enough will cause a catastrophic breakdown in the sparse structure causing it to shatter like glass (known as friability). Despite the fact that it is prone to shattering, it is very strong structurally, able to hold over 2000 times its own weight. Its impressive load bearing abilities are due to the dendritic microstructure, with spherical ...

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Aerogel, Aerogel - Properties, Aerogel - Silica aerogel, Aerogel - Uses, Aerogel - Production

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The final process induced on the now almost complete bolt, is the application of an anti-corrosive layer, to stop oxidation, called "blackening". This process chemically coats the surface of ferrous metals, creating a strong barrier against humidity and corrosion. There are two types of blackening processes: hot blackening cold blackening. Assuming that bolts are hot blackened; the implementation of this process is as follows: Hot blackening involves dipping the bolt into six different tanks. The bolt is u ...

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Bolt manufacturing process, Bolt manufacturing process - Heading, Bolt manufacturing process - Thread rolling, Bolt manufacturing process - Blackening, Bolt manufacturing process - Materials, Bolt manufacturing process - Work-holding fixtures

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Silica aerogel is made by drying a hydrogel composed of colloidal silica in an extreme environment. Specifically, the process starts with a liquid alcohol like ethanol which is mixed with a silicon alkoxide precursor to form a silicon dioxide sol gel (silica gel). Then, through a process called supercritical drying, the alcohol is removed from the gel. This is typically done by exchanging the ethanol for liquid carbon dioxide and then bringing the carbon dioxide above its critical point. The end result removes all liquid from the gel and replaces it with gas, without allowing the gel ...

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Aerogel, Aerogel - Properties, Aerogel - Silica aerogel, Aerogel - Uses, Aerogel - Production

Read more here: » Aerogel: Encyclopedia II - Aerogel - Production

Silica aerogel is the most common type of aerogel and the most extensively studied and used. It is a silica-based substance and the world's lowest-density solid. It is an advanced version of silica gel. The latest and lightest versions of this substance have a density 1.9 mg/cm3 (i.e., 1/530 as dense as water), and are produced by the Lawrence Livermore National Laboratory. It has extremely low thermal conductivity (approx. 0.017 W/(m·K)), which gives it remarkable insulative properties and ...

See also:

Aerogel, Aerogel - Properties, Aerogel - Silica aerogel, Aerogel - Uses, Aerogel - Production

Read more here: » Aerogel: Encyclopedia II - Aerogel - Silica aerogel