Deserts

Weathering results in the breaking up of rock into smaller components which then can be transported by agents such as water (rivers, sea currents), wind (deserts) and ice... 

Providing the land surfaoe above a reservoir is relatively flat, it is generally cheaper to drill and maintain a vertical well than to access a reservoir from a location that requires a deviated borehole. In unpopulated areas such as desert or jungle looations It is common to find that the pattern of wellheads at surface closely reflects the pattern In which wells penetrate the reservoir. However, in many eases constraints will be planed on drill site availability as a result of housing, environmental concerns or topography. In such conditions wells may be drilled in clusters from one or a number of sites as elose as possible to the surface location of the reservoir. 

MFL is currently being used for the inspection of hundreds of kilometres of piping in the Oman desert, see figure 5., whereby an inspection rate of one kilometre per day is easily achieved. Try to realise what effort would have been needed if this would have been done with conventional ultrasonic wall thickness measurements. 

Important sources of boron are ore rasorite (kernite) and tincal (borax ore). Both of these ores are found in the Mojave Desert. Tincal is the most important source of boron from the Mojave. Extensive borax deposits are also found in Turkey. 

One fine summer evening, I was returning by the last omnibus, outside as usual, through the deserted streets of the metropolis, which are at other times so full of life. I fell into a reverie and lo the atoms were gamboling before my eyes.. .. I saw how, frequently, two smaller atoms united to form a pair, how a larger one embraced two smaller ones how still larger ones kept hold of three or even four of the smaller whilst the whole kept whirling... 

Applications for synthetic character impact items include cough drops, toothpaste, chewing gum, candies, soft drinks, baked goods, gelatin deserts, ice cream, margarine, and cheese. 

Derived plant and animal products make better use or upgrade the nutritional quaHty of already existing materials or products. Synthetic and manufactured products arose from knowledge of the functional properties of food ingredients and of human and animal nutrition that involved more precise definition of nutrient requirements for growth, reproduction, lactation, and body maintenance in both humans and domestic Hvestock. Pood products have been developed to meet human needs under abnormal environments, eg, military rations for arctic, tropical, or desert environments, and special products for astronauts ia space flights. 

Mineral Deposits. The only iodine obtained from minerals has been a by-product of the processing of nitrate ores in Chile. CaUche occurs in the Atacama desert of Northern Chile and west of the Andes mountains. The Atacama desert is known as the driest of the world s deserts, where measurable (>1 mm) rainfalls may be as infrequent as once every 5—29 years (58). The caUche deposits occur in an area averaging 700 km (north—south) by 30 km (east—west). The iodine may total over 5 x 10 t (59). 

The above-mentioned codes contain requirements for accelerated durabiUty tests. In addition, interlayer manufacturers and laminators expose test samples for several years under extreme weather conditions, eg, the Florida coast and Arizona desert. The laminated products weather extremely well, with no change in the plastic interlayer. Occasionally, clouding is noted around the edges when exposed to high humidity for long periods, but this is reversible. Colored areas of PVB laminates may fade while subjected to extensive uv/solar irradiation, which could cause an appearance issue. This has not, however, been shown to alter the laminate s other performance properties. 

In desert or tropical climates skin dries into a hard mass that does not soften even when soaked in water. By shaping a skin to a desired form and then drying, however, useful articles such as dmm heads and shields can be made. Tanning for useful leather is not a simple skill. 

In the remote Negev desert region of Israel, oil shale is being burned in a duidized-bed combustor to supply process heat and produce electric power. Unlike the Estonian kukersite, this oil shale is lean, about 63 L/1, but is being mined to access an undedying phosphate deposit (26). 

The Chilean nitrate deposits are located in the north of Chile, in a plateau between the coastal range and the Andes mountains, in the Atacama desert. These deposits are scattered across an area extending some 700 km in length, and ranging in width from a few kilometers to about 50 km. Most deposits are in areas of low rehef, about 1200 m above sea level. The nitrate ore, caUche, is a conglomerate of insoluble and barren material such as breccia, sands, and clays (qv), firmly cemented by soluble oxidized salts that are predominandy sulfates, nitrates, and chlorides of sodium, potassium, and magnesium. Cahche also contains significant quantities of borates, chromates, chlorates, perchlorates, and iodates. 

Numerous theories exist as to how the Chilean deposits formed and survived. It has been postulated that the unique nitrate-rich caUche deposits of northern Chile owe their existence to an environment favorable to accumulation and preservation of the deposits, rather than to any unusual source of the saline materials (2). The essential conditions are an extremely arid climate similar to that of the Atacama desert in the 1990s, slow accumulation during the late Tertiary and Quaternary periods, and a paucity of nitrate-utilizing plants and soil microorganisms. 

Carbon. Most of the Earth s supply of carbon is stored in carbonate rocks in the Hthosphere. Normally the circulation rate for Hthospheric carbon is slow compared with that of carbon between the atmosphere and biosphere. The carbon cycle has received much attention in recent years as a result of research into the possible relation between increased atmospheric carbon dioxide concentration, most of which is produced by combustion of fossil fuel, and the "greenhouse effect," or global warming. Extensive research has been done on the rate at which carbon dioxide might be converted to cellulose and other photosyntheticaHy produced organic compounds by various forms of natural and cultivated plants. Estimates also have been made of the rate at which carbon dioxide is released to soil under optimum conditions by various kinds of plant cover, such as temperature-zone deciduous forests, cultivated farm crops, prairie grassland, and desert vegetation. 

Freshwater with less than 500 ppm (or 0.05%) dissolved soHds is generally considered to be potable. Rain is the source of freshwater, and its precipitation of >1.3 x 10 m /d over the earth s surface averages about 1.05 m (depth) per year. Extremes range from almost 2ero ia North Chile s desert borderiag the Pacific Coast to > 25.4 m ia some tropical forests and on some high slopes where the high, cold mountains condense floods from the clouds. 

Receptor Models. Receptor models, by their formulation, are effective in determining the contributions of various sources to particulate matter concentrations. In classic studies, sources contributing to airborne particle loadings have been identified in Washington, D.C. (78), St. Louis (9,24), Los Angeles (7,12), Portiand, Oregon (78), and Boston (79—81), as well as other areas including the desert (82). 

D. L. Fife and A. R. Brown, eds.. Geology andMineral Wealth of the California Desert, South Coast Geological Society, Santa Ana, Calif., 1980, Chapts. 

The use of chemical agents in battie imposes a significant burden on troops because of the cumbersome nature of the protective clothing and the attendant heat load in hot climate situations. This factor alone imposes a burden on potential target personnel, lowering their effectiveness. U.S. troops in the 1991 Mideast war Desert Storm were provided with protective gear that did not deter them with regard to the outcome of the action. 

Occurrence. Iodine [7553-56-2] is widely distributed in the Hthosphere at low concentrations (about 0.3 ppm) (32). It is present in seawater at a concentration of 0.05 ppm (33). Certain marine plants concentrate iodine to higher levels than occur in the sea brine these plants have been used for their iodine content. A significant source of iodine is caUche deposits of the Atacama Desert, Chile. About 40% of the free world s iodine was produced in Japan from natural gas wells (34), but production from Atacama Desert caUche deposits is relatively inexpensive and on the increase. By 1992, Chile was the primary world producer. In the United States, underground brine is the sole commercial source of iodine (35). Such brine can be found in the northern Oklahoma oil fields originating in the Mississippian geological system (see Iodine and iodine compounds). 

A large reserve of caUche ore bearing iodine is being processed in the Atacama Desert. Production of iodine there is relatively inexpensive. About 40% of the world supply of iodine is made from these Chilean deposits. The process consists of leaching the caUche with water. Brine is stripped of iodine using an organic solvent. The iodine is then removed from the solvent to form a slurry. SoHd-phase iodine is separated from the slurry in conventional flotation cells, dried, and packaged. Details of the process are proprietary. 

Jojoba is a desert crop that gives a small bean containing about 50% of a wax, a fatty acid ester with a fatty alcohol. The only other large source of such a wax is sperm whale oil, traditionally used in fine lubricants (see Lubrication and lubricants). Because the sperm whale is an endangered species, relatively Httle sperm whale oil is available and there is a large market for a substitute. Jojoba oil has been found to be usable for most of these appHcations. The jojoba oil is obtained by simply pressing the nut followed by conventional refining. Some jojoba oil is used in cosmetics (qv). 

The problems with jojoba as a commercial crop are the usual ones of domestication and cultivation. It is a slow-growing plant, available only in the wild and therefore has very wide genetic variabiUty. Efforts are underway to select the most promising variants and cultivate these as a crop in the southwestern United States deserts (7). A possible alternative for producing jojoba oil is to culture plant embryos in bioreactors (see Cell culture technology). 

National Research Council,Feasibilityfor Cultivation on Indian Reservation in the Sonoran Desert Region, National Academy of Sciences, Washington, D.C., 1977. 

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