porous

The Rhine is the busiest river in the world for transport ships. Inland vessels use the river to reach the major cities in Germany, Eastern France and Switzerland to transport bulk goods, liquids, containers AND passengers into the hinterland of the Port of Rotterdam and the ports of Amsterdam and Antwerp. Many millions of tons of goods are transported upstream yearly from these three sea ports to the industries near Nijmegen, Duisburg, Düsseldorf, Neuss, Köln, Koblenz, Mainz, Mannheim, Karlsruhe, Str ...

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 - Navigation

Source: Energy Statistics from the U.S. Government (Ordered by amount (barrels per day) produced in 2004): Saudi Arabia (OPEC) Russia United States 1 Iran (OPEC) Mexico 1 China 1 Norway 1 Canada 1 Venezuela (OPEC) 1 United Arab Emirates (OPEC) Kuwait (OPEC) Nigeria (OPEC) United Kingdom 1 Iraq (OPEC) 2 See also:

Petroleum, Petroleum - Origin, Petroleum - Biogenic theory, Petroleum - Abiogenic theory, Petroleum - Composition, 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 - Books about the petroleum industry, Petroleum - Films about petroleum, Petroleum - Writers covering the petroleum industry

Read more here: » Petroleum: Encyclopedia II - Petroleum - Top petroleum-producing countries

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 ...

See also:

Petroleum, Petroleum - Origin, Petroleum - Biogenic theory, Petroleum - Abiogenic theory, Petroleum - Composition, 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 - 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 ...

See also:

Petroleum, Petroleum - Origin, Petroleum - Biogenic theory, Petroleum - Abiogenic theory, Petroleum - Composition, 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 - Books about the petroleum industry, Petroleum - Films about petroleum, Petroleum - Writers covering the petroleum industry

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

In refining, the component chemicals of petroleum are separated by fractional distillation, which is a separation based on relative boiling points (or equivalently relative volatility). The different products (in order of boiling points) include light gases (e.g. methane, ethane, propane), gasoline, jet fuel, kerosene, diesel, gasoil, paraffin wax, and asphalt. Subtler techniques, such as gas chromatography, HPLC, and GC-MS, can separate some fractions of petroleum into individual compounds; these are analytical chemistry methods used ...

See also:

Petroleum, Petroleum - Origin, Petroleum - Biogenic theory, Petroleum - Abiogenic theory, Petroleum - Composition, 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 - Books about the petroleum industry, Petroleum - Films about petroleum, Petroleum - Writers covering the petroleum industry

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

The presence of oil has significant social and environmental impacts, from accidents and routine activities such as seismic exploration, drilling, and generation of polluting wastes. Oil extraction is costly and sometimes environmentally damaging, although Dr. John Hunt from Woods Hole pointed out in a 1981 paper that over 70% of the reserves in the world are associated with visible macroseepages, and many oil fields are found due to natural leaks. Offshore exploration and extraction of oil disturbs the surrounding marine environment. Extrac ...

See also:

Petroleum, Petroleum - Origin, Petroleum - Biogenic theory, Petroleum - Abiogenic theory, Petroleum - Composition, 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 - Books about the petroleum industry, Petroleum - Films about petroleum, Petroleum - Writers covering the petroleum industry

Read more here: » Petroleum: Encyclopedia II - Petroleum - Environmental effects

Main article: Hubbert Peak 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 actually take place are highly dependent on the past production ...

See also:

Petroleum, Petroleum - Origin, Petroleum - Biogenic theory, Petroleum - Abiogenic theory, Petroleum - Composition, 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 - Books about the petroleum industry, Petroleum - Films about petroleum, Petroleum - Writers covering the petroleum industry

Read more here: » Petroleum: Encyclopedia II - Petroleum - Future of oil

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 ...

See also:

Petroleum, Petroleum - Origin, Petroleum - Biogenic theory, Petroleum - Abiogenic theory, Petroleum - Composition, 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 - Books about the petroleum industry, Petroleum - Films about petroleum, Petroleum - Writers covering the petroleum industry

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

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 ...

See also:

Petroleum, Petroleum - Origin, Petroleum - Biogenic theory, Petroleum - Abiogenic theory, Petroleum - Composition, 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 - Books about the petroleum industry, Petroleum - Films about petroleum, Petroleum - Writers covering the petroleum industry

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

The aerodynamic boundary layer was discovered by Ludwig Prandtl at the beginning of the twentieth century and represents one of the greatest discoveries in the history of aerodynamics. It is particularly important in aerodynamics because it is directly responsible for the drag experienced by a body immersed in a fluid. In high-performance designs, such as sailplanes and commercial transport aircraft, much attention is paid to controlling the behavior of the boundary layer to minimize drag. Two effects must to be considered. ...

See also:

Boundary layer, Boundary layer - Aerodynamics, Boundary layer - Boundary layer equations, Boundary layer - Turbulent boundary layers, Boundary layer - Boundary layer turbine, Boundary layer - Bibliography

Read more here: » Boundary layer: Encyclopedia II - Boundary layer - Aerodynamics

The treatment of turbulent boundary layers is far more difficult due to the time-dependent variation of the flow properties. One of the most widely used techniques in which turbulent flows are tackled is to apply Reynolds decomposition. Here the instantaneous flow properties are decomposed into a mean and fluctuating component. Applying this technique to the boundary layer equations give the full turbulent boundary layer equations not often given in literature, viz.

Boundary layer, Boundary layer - Aerodynamics, Boundary layer - Boundary layer equations, Boundary layer - Turbulent boundary layers, Boundary layer - Boundary layer turbine, Boundary layer - Bibliography

Read more here: » Boundary layer: Encyclopedia II - Boundary layer - Turbulent boundary layers

Bhutan remains one of the most secluded nations in the world, and foreigners are not permitted to travel to many of its areas to minimise the effects of tourism on the local culture. In contrast to Nepal, which is well-known as a budget travel destination, Bhutan attempts to limit tourism to group tourists willing to pay upwards of US$100 per day. The traditional dress for Ngalong and Sharchop men is the gho, a knee-length robe tied at the waist by a cloth belt known as the kera. Women wear an ankle-length dress, the ...

See also:

Bhutan, Bhutan - The Name, Bhutan - History, Bhutan - Geography, Bhutan - Economy, Bhutan - Government and politics, Bhutan - Districts, Bhutan - Military and foreign affairs, Bhutan - Demographics, Bhutan - Culture, Bhutan - Current Affairs, Bhutan - Notes

Read more here: » Bhutan: Encyclopedia II - Bhutan - Culture

The Royal Bhutan Army is Bhutan's military service. It includes the Royal Bodyguard and the Royal Bhutan Police. Membership is voluntary, and the minimum age for recruitment is 18. The standing army numbers about 6,000 and is trained by the Indian Army.[4] It has an annual budget of about US$13.7 million—1.8% of the GDP. India handles most of Bhutan's foreign affairs by way of conducting formal communications to and from other countries as Bhutan h ...

See also:

Bhutan, Bhutan - The Name, Bhutan - History, Bhutan - Geography, Bhutan - Economy, Bhutan - Government and politics, Bhutan - Districts, Bhutan - Military and foreign affairs, Bhutan - Demographics, Bhutan - Culture, Bhutan - Current Affairs, Bhutan - Notes

Read more here: » Bhutan: Encyclopedia II - Bhutan - Military and foreign affairs

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 in dimensions of [length2 time-1], [m2 s-1]See 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

Read more here: » Fick's law of diffusion: Encyclopedia II - Fick's law of diffusion - Fick's First Law

The diffusion coefficient at different temperatures is often found to be well predicted by Where: D is the diffusion coefficient D0 is the maximum diffusion coefficient (at infinite temperature) Q is the activation energy for diffusion in dimensions of [energy / parts] T is the temperature in units of [absolute temperature] (Kelvin or Rankine) R i ...

See 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

Read more here: » Fick's law of diffusion: Encyclopedia II - Fick's law of diffusion - Temperature dependence of the Diffusion coefficient

Aesthetic and artistic considerations have often been part of the formation of the pottery vessels, however modern mass production techniques have replaced the traditional role of pottery with mechanized reproduction, which has in turn caused the potter to be more focused on the aesthetic than the utilitarian in industrialized nations. Traditionally, different world regions have produced different types of clay, also called bodies, with the potter digging clay out of natural banks in his own 'back yard.' In modern times, potter ...

See also:

Pottery, Pottery - Types of pottery, Pottery - Techniques, Pottery - Forming techniques, Pottery - Decorative and finishing techniques, Pottery - Glazing and firing techniques, Pottery - Production stages, Pottery - History, Pottery - Palaeolithic pottery, Pottery - Neolithic pottery, Pottery - Reference

Read more here: » Pottery: Encyclopedia II - Pottery - Types of pottery

The first law gives rise to the formula It states that the rate of diffusion of a gas across a membrane is Constant for a given gas at a given temperature by an experimentally determined factor, K Proportional to the surface area over which diffusion is taking place, A Proportional to the difference in partial pressures of the gas across the membrane, P2 − P1< ...

See 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

Read more here: » Fick's law of diffusion: Encyclopedia II - Fick's law of diffusion - A Biological Perspective

The question of whether Bhutan is a sovereign country is a difficult one. Bhutan was treated as a suzerainty by the British Raj, which set up a monarchy and allowed it to administer Bhutan's internal affairs. Foreign and defense policy, however, was decided by the British. In 1949, after Indian independence, Bhutan and India agreed to a ten-article, perpetual treaty which effectively continued the relationship, but with India taking the place of Britain as the imperial power. That is, India agreed not to interfere in Bhutan's internal relati ...

See also:

Bhutan, Bhutan - The Name, Bhutan - History, Bhutan - Geography, Bhutan - Economy, Bhutan - Government and politics, Bhutan - Districts, Bhutan - Military and foreign affairs, Bhutan - Demographics, Bhutan - Culture, Bhutan - Current Affairs, Bhutan - Notes

Read more here: » Bhutan: Encyclopedia II - Bhutan - Government and politics

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 ...

See also:

Bhutan, Bhutan - The Name, Bhutan - History, Bhutan - Geography, Bhutan - Economy, Bhutan - Government and politics, Bhutan - Districts, Bhutan - Military and foreign affairs, Bhutan - Demographics, Bhutan - Culture, Bhutan - Current Affairs, Bhutan - Notes

Read more here: » Bhutan: Encyclopedia II - Bhutan - Economy

Although some environmentalists claim that Cancún is an environmental disaster, Siegel says that is not true. There has obviously been environmental damage and the situation could deteriorate rapidly, he reports, but at present (February 2005) Cancún's main problem is a breakdown of garbage collection and disposal as a result of political conflicts that will hopefully be solved by a new administration elected February 6, 2005. Sewage treatment is another danger point, he says. Although approximately 75% of the city has public sewer lines, ...

See also:

Cancún, Cancún - Geography, Cancún - History, Cancún - Environmental concerns, Cancún - Tourism in Cancún, Cancún - Hurricane Wilma, Cancún - Sister cities

Read more here: » Cancún: Encyclopedia II - Cancún - Environmental concerns

In the early 1950s Cancún was an almost unpopulated and undeveloped island just off the Caribbean Sea coast of the Yucatán peninsula, home to three caretakers of a coconut plantation and small Pre-Columbian ruins of the Maya civilization. The government of Mexico decided to develop a tourist resort on Cancún, which was originally financed by a USD $27 million loan from the International Development Bank. A causeway was built to link Cancún to the mainland, and an international airport was built, along with what was at first a model city ...

See also:

Cancún, Cancún - Geography, Cancún - History, Cancún - Environmental concerns, Cancún - Tourism in Cancún, Cancún - Hurricane Wilma, Cancún - Sister cities

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

Caliche generally forms when minerals are leached from the upper layer of the soil (the A horizon) and accumulate in the next layer (the B horizon), at depths of approximately 3 to 10 feet under the surface. Caliche generally consists of carbonates in semiarid regions, while in arid regions, less soluble minerals will form caliche layers after all the carbonates have been leached from the soil. The calcium carbonate that is deposited accumulates, first forming grains, then small clumps, then a discernable layer, and finally a thicker, solid ...

See also:

Caliche, Caliche - How it forms, Caliche - Economic uses, Caliche - Building applications, Caliche - Sugar refining, Caliche - Chilean caliche, Caliche - Caliche and Gardening, Caliche - Problems Caliche Causes, Caliche - Fixing these problems

Read more here: » Caliche: Encyclopedia II - Caliche - How it forms