porous

Fick's Second Law is used in non-steady state diffusion, i.e., when the concentration within the diffusion volume changes with respect to time. Where Φ is the concentration in dimensions of [parts length-3], [mol dm-3] t is time [s] 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

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Stone tools, weapons, and remnants of large stone structures provide evidence that Bhutan was inhabited as early as 2000 BC. Historians have theorised that the state of Lhomon (literally, "southern darkness"), or Monyul ("Dark Land", a reference to the Monpa – the aboriginal peoples of Bhutan) may have existed between 500 BC and 600 AD. The names Lhomon Tsendenjong (Sandalwood Country), and Lhomon Khashi, or Southern ...

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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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Lycopene is a terpene assembled from 8 isoprene units. The color of lycopene is due to its many conjugated carbon double bonds. Each double bond reduces the energy required for electrons to transition to higher energy states, allowing the molecule to absorb visible light of progressively shorter wavelengths. Lycopene absorbs most of the visible spectrum, so it appears red. If lycopene is oxidized (for example, by reacting with bleaches or acids), the double bonds between carbon atoms will be broken, cleaving the molecule into s ...

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Lycopene, Lycopene - Structure, Lycopene - Food Coloring

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In order for an oil reservoir to form, it must be shaped in a way that prevents the escape of hydrocarbons that migrate into it. Petroleum geologists have classified two types of reservoir shapes, or traps: Structural traps are formed by a deformation in the rock layer that contains the hydrocarbons (e.g., fault traps and anticlinal traps). Stratigraphic traps are formed when other beds seal a reservoir bed or when the permeability changes (facies change) within the reservoir bed itself. A reservoir can also be formed by a ...

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Oil reservoir, Oil reservoir - Origin and accumulation, Oil reservoir - Production, Oil reservoir - Types

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A river conducts water by constantly flowing perpendicular to the elevation curve of its bed, thereby converting the positional energy of the water into kinetic energy. Where a river flows over relatively flat areas, the river will meander: start to form loops and snake through the plain by eroding the river banks. Sometimes the river will cut off a loop, shortening the channel and forming an oxbow lake from the cut off section. Rivers that carry large amounts of sediment develop conspicuous deltas at their mouths. Rivers whose mouths are in saline tidal waters may form estuaries. Over time, rivers cut away at their beds, eventua ...

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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

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The deduction of the boundary layer equations was perhaps one of the most important advances in aerodynamics. Using an order of magnitude analysis, the well-known governing Navier-Stokes equations of viscous fluid flow can be greatly simplified within the boundary layer. Notably, the characteristic of the partial differential equations (PDE) becomes parabolic, rather than the elliptical form of the full Navier-Stokes equations. This greatly simplifies the solution of the equations. By making the boundary layer approximation, the flow ...

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

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There are a variety of tasks for which aerogels are used. Commercially, aerogels have been used in granular form to add insulation to skylights. After several trips on the Vomit Comet, one research team has shown that producing aerogel in a weightless environment can produce more uniform size of the particles, and reduce this Rayleigh scattering effect in silica aerogel, thus making the aerogel less blue and more transparent. Transparent silica aerogel would be very suitable as a thermal insulation material for windows, significantly limit ...

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

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The initial process is a cold forging process to produce a near net shape, called "heading", to produce the overall bolt shape. Bolts have a large head to shank ratio. Generally, they are longer than 1½ times the diameter, have multiple diameters, and require a geometrical shape (i.e. the rounded head). Furthermore, this production method is probably used because cold heading has a very high production rate, and produces virtually no waste material. The process works as follows: the bar stock is fed into a machine, called a "former". ...

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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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Native Americans in the area have created a detailed legend concerning the three smoking mountains that guard the Columbia River. According to their Bridge of the Gods tale, Wyeast (Mount Hood) and Pahto (Mount Adams; also called Paddo or Klickitat by natives) were the sons of Great Spirit. The brothers both competed for the love of the beautiful La-wa-la-clough (Mount St. Helens). When La-wa-la-clough chose Pahto, Wyeast struck his brother so hard that Pahto's head was flattened and Wyeast took La-wa-la-clough from him (thus attempting to e ...

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Mount Adams Washington, Mount Adams Washington - History, Mount Adams Washington - Glaciers, Mount Adams Washington - Geology, Mount Adams Washington - Summit area, Mount Adams Washington - Area around Adams, Mount Adams Washington - Reference, Mount Adams Washington - External link

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Downland is formed when chalk formations are raised above the surrounding rocks. The chalk slowly erodes to form characteristic rolling hills and valleys. Chalk downland formations typically have a marked scarp slope on one side, which is very steep, and a dip slope on the other, which is much shallower. Where the downs meet the sea, characteristic white chalk cliffs can be formed, such as the White cliffs of Dover.< ...

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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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The population of Bhutan, once estimated at several million, has now been officially downgraded--by the Bhutanese government--to 750,000, after a census in the early nineties. Some Nepali activists claim that the downgrade was motivated by a desire to minimize the proportion of immigrant ethnic Nepali population. However most believe that the population was artifically inflated in the seventies because of an earlier perception that nations with populations of less than a million would not be admitted to the ...

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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 - Culture, Bhutan - Current Affairs, Bhutan - Notes

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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 ...

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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 - Culture, Bhutan - Current Affairs, Bhutan - Notes

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Sedimentary rocks are formed from overburden pressure as particles of sediment are deposited out of air, ice, or water flows carrying the particles in suspension. As sediment deposition builds up, the overburden (or lithostatic) pressure squeezes the sediment into layered solids in a process known as lithification ("rock formation") and the original connate fluids are expelled. The term diagenesis is used to describe all the chemical, physical, and biological changes undergone by a sediment after its initial deposition and during and after its lithification, ...

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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 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 ...

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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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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 ...

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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 population of Bhutan, once estimated at several million, has now been officially downgraded--by the Bhutanese government--to 750,000, after a census in the early nineties. Some Nepali activists claim that the downgrade was motivated by a desire to minimize the proportion of immigrant ethnic Nepali population. However most believe that the population was artifically inflated in the seventies because of an earlier perception that nations with ...

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 - The Nepali minority and human rights issues, Bhutan - Language, Bhutan - Culture, Bhutan - Notes

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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 ...

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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 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 ...

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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

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

Ice (mostly in the form of glaciers) covers about 6.2 mile² (16 km²) of the mountain's upper cone and is fed by ample snow and rainfall every year. Water percolates through the very porous interior of the main cone and exits near the volcano's base as springs. Glaciers cover a total of 2.5% of Adams' surface but during the last ice age about 90% of the mountain had glaciers on it. Most of the largest extant glaciers (including the Adams, Klickitat, Lyman, Salmon, and White ) originate from Adams' summit ice cap. On the northwest fac ...

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Mount Adams Washington, Mount Adams Washington - History, Mount Adams Washington - Glaciers, Mount Adams Washington - Geology, Mount Adams Washington - Summit area, Mount Adams Washington - Area around Adams, Mount Adams Washington - Reference, Mount Adams Washington - External link

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Adams is made of several overlapping cones that together form an 18 mile (29 km) diameter base which is elongated in a north-south direction and covers an area of 250 mile² (650 km²). The volcano has a volume of 85 mile³ (350 km³) placing it second only to Mount Shasta in that category among the Cascade stratovolcnoes. Mount Adams was created by the subduction of the Juan de Fuca plate, which is locate ...

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Mount Adams Washington, Mount Adams Washington - History, Mount Adams Washington - Glaciers, Mount Adams Washington - Geology, Mount Adams Washington - Summit area, Mount Adams Washington - Area around Adams, Mount Adams Washington - Reference, Mount Adams Washington - External link

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SpongeBob is extremely sweet, generous, friendly, and most of all, trusting. He has a buck-toothed grin, tremendously expressive face and square body that complement his pure and good nature. SpongeBob will rarely knowingly do wrong or harm to anyone and never without remorse. However, he has been known to shout and curse (even "obscenities") when angry or frustrated. He dislikes scary things and stinky thin ...

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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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