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Depletion Silvering
Depletion may refer to: Environment * Resource depletion, decline of resources * Gas depletion, decline of oil supply * Nutrient depletion, loss of nutrients in a habitat * Oil depletion, decline of oil supply * Overdrafting, extracting groundwater beyond the equilibrium yield of an aquifer * Ozone depletion, a decline in the total amount of ozone in Earth's atmosphere Physics * Depletion force, an effective force in molecular and colloidal systems * Depletion region, in semiconductor physics * Grain boundary depletion, a mechanism of corrosion Other uses * Ego depletion, idea that self-control or willpower draws upon a limited pool of mental resources that can be used up * Depletion (accounting) Depletion is an accounting and tax concept used most often in the mining, timber, and petroleum industries. It is similar to depreciation in that it is a cost recovery system for accounting and tax reporting: "The depletion deduction" allows an o ..., an accounting and tax concept use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resource Depletion
Resource depletion is the consumption of a resource faster than it can be replenished. Natural resources are commonly divided between renewable resources and non-renewable resources (see also mineral resource classification). Use of either of these forms of resources beyond their rate of replacement is considered to be resource depletion. The value of a resource is a direct result of its availability in nature and the cost of extracting the resource, the more a resource is depleted the more the value of the resource increases. There are several types of resource depletion, the most known being: Aquifer depletion, deforestation, mining for fossil fuels and minerals, pollution or contamination of resources, slash-and-burn agricultural practices, soil erosion, and overconsumption, excessive or unnecessary use of resources. Resource depletion is most commonly used in reference to farming, fishing, mining, water usage, and consumption of fossil fuels. Depletion of wildlife popul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gas Depletion
Gas depletion is the decline in natural gas production of a well, gas field, or geographic area. Depletion rate According to the US Energy Information Administration, in 1980 the world had enough proved gas reserves to last 48 years at the 1980 rate of production. Cumulative world gas production from 1980 through 2011 was greater than the proved gas reserves in 1980. In 2011, world proved gas reserves were enough to last 58 years at 2011 production levels, even though the 2011 production rate was more than double the 1980 rate. At current consumption levels, there are 52 years of proven gas reserves left. However, proven gas reserves have been consistently increasing over time. Role of new technology As new technologies for natural gas production are discovered, the world's ultimate reserves can grow. Although some predictions of ultimate reserve recovery include provisions for new technology, not every magnitude of breakthrough can be accurately accounted for. More than half ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nutrient Depletion
Nutrient depletion is a form of resource depletion and refers to the loss of nutrients and micronutrients in a habitat or parts of the biosphere, most often the soil (soil depletion, soil degradation). On the level of a complete ecological niche or ecosystem, nutrient depletion can also come about via the loss of the nutrient substrate ( soil loss, wetland loss, etc.). Nutrients are usually the first link in the food chain, thus a loss of nutrients in a habitat will affect nutrient cycling and eventually the entire food chain. Nutrient depletion can refer to shifts in the relative nutrient composition and overall nutrient quantity (i.e. food abundance). Human activity has changed both in the natural environment extensively, usually with negative effects on wildlife flora and fauna. The opposite effect is known as eutrophication or nutrient pollution.Both refer to water bodies instead of soil, because an overabundance of nutrients will usually be washed out from the soil Both dep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oil Depletion
Oil depletion is the decline in oil production of a well, oil field, or geographic area. The Hubbert peak theory makes predictions of production rates based on prior discovery rates and anticipated production rates. Hubbert curves predict that the production curves of non-renewing resources approximate a bell curve. Thus, according to this theory, when the peak of production is passed, production rates enter an irreversible decline. The United States Energy Information Administration predicted in 2006 that world consumption of oil will increase to (mbd) in 2015 and 118 million barrels per day in 2030. With 2009 world oil consumption at 84.4 mbd, reaching the projected 2015 level of consumption would represent an average annual increase between 2009 and 2015 of 2.7% per year. Resource availability Earth's natural oil supply is effectively fixed because petroleum is naturally formed far too slowly to be replaced at the rate at which it is being extracted. Over many ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overdrafting
Overdrafting is the process of extracting groundwater beyond the equilibrium yield of an aquifer. Groundwater is one of the largest sources of fresh water and is found underground. Groundwater depletion is comparable to a bank account in which more money is withdrawn than deposited. The primary cause of groundwater depletion is the excessive pumping of groundwater up from underground aquifers. There are two sets of yields: safe yield and sustainable yield. Safe yield is the amount of groundwater that can be withdrawn over a period of time without exceeding the long-term recharge rate or affecting the aquifer integrity. Sustainable yield is the amount of water extraction that can be sustained indefinitely without negative hydrological impacts, taking into account both recharge rate and surface water impacts. There are two types of aquifers: confined and unconfined. In confined aquifers, there is an overbearing layer called aquitard, which contains impermeable materials through wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ozone Depletion
Ozone depletion consists of two related events observed since the late 1970s: a steady lowering of about four percent in the total amount of ozone in Earth's atmosphere, and a much larger springtime decrease in stratospheric ozone (the ozone layer) around Earth's polar regions. The latter phenomenon is referred to as the ozone hole. There are also springtime polar tropospheric ozone depletion events in addition to these stratospheric events. The main causes of ozone depletion and the ozone hole are manufactured chemicals, especially manufactured halocarbon refrigerants, solvents, propellants, and foam-blowing agents (chlorofluorocarbons (CFCs), HCFCs, halons), referred to as ozone-depleting substances (ODS). These compounds are transported into the stratosphere by turbulent mixing after being emitted from the surface, mixing much faster than the molecules can settle. Once in the stratosphere, they release atoms from the halogen group through photodissociation, which ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Depletion Force
A depletion force is an effective attractive force that arises between large colloidal particles that are suspended in a dilute solution of ''depletants'', which are smaller solutes that are preferentially excluded from the vicinity of the large particles. One of the earliest reports of depletion forces that lead to particle coagulation is that of Bondy, who observed the separation or "creaming" of rubber latex upon addition of polymer depletant molecules (sodium alginate) to solution. More generally, depletants can include polymers, micelles, osmolytes, ink, mud, or paint dispersed in a continuous phase. Depletion forces are often regarded as entropic forces, as was first explained by the established Asakura–Oosawa model. In this theory the depletion force arises from an increase in osmotic pressure of the surrounding solution when colloidal particles get close enough such that the excluded cosolutes (depletants) cannot fit in between them. Because the particles were consider ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Depletion Region
In semiconductor physics, the depletion region, also called depletion layer, depletion zone, junction region, space charge region or space charge layer, is an insulating region within a conductive, doped semiconductor material where the mobile charge carriers have been diffused away, or have been forced away by an electric field. The only elements left in the depletion region are ionized donor or acceptor impurities. This region of uncovered positive and negative ions is called the depletion region due to the depletion of carriers in this region. The depletion region is so named because it is formed from a conducting region by removal of all free charge carriers, leaving none to carry a current. Understanding the depletion region is key to explaining modern semiconductor electronics: diodes, bipolar junction transistors, field-effect transistors, and variable capacitance diodes all rely on depletion region phenomena. Formation in a p–n junction A depletion region for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grain Boundary Depletion
In materials science, intergranular corrosion (IGC), also known as intergranular attack (IGA), is a form of corrosion where the boundaries of crystallites of the material are more susceptible to corrosion than their insides. (''Cf.'' transgranular corrosion.) Description This situation can happen in otherwise corrosion-resistant alloys, when the grain boundaries are depleted, known as ', of the corrosion-inhibiting elements such as chromium by some mechanism. In nickel alloys and austenitic stainless steels, where chromium is added for corrosion resistance, the mechanism involved is precipitation of chromium carbide at the grain boundaries, resulting in the formation of chromium-depleted zones adjacent to the grain boundaries (this process is called sensitization). Around 12% chromium is minimally required to ensure passivation, a mechanism by which an ultra thin invisible film, known as passive film, forms on the surface of stainless steels. This passive film protects the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ego Depletion
Ego depletion is the idea that self-control or willpower draws upon a limited pool of mental resources that can be used up (with the word "ego" used in the psychoanalytic sense rather than the colloquial sense). When the energy for mental activity is low, self-control is typically impaired, which would be considered a state of ego depletion. In particular, experiencing a state of ego depletion impairs the ability to control oneself later on. A depleting task requiring self-control can have a hindering effect on a subsequent self-control task, even if the tasks are seemingly unrelated. Self-control plays a valuable role in the functioning of the self on both individualistic and interpersonal levels. Ego depletion is therefore a critical topic in experimental psychology, specifically social psychology, because it is a mechanism that contributes to the understanding of the processes of human self-control. There have both been studies to support and to question the validity of ego-de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Depletion (accounting)
Depletion is an accounting and tax concept used most often in the mining, timber, and petroleum industries. It is similar to depreciation in that it is a cost recovery system for accounting and tax reporting: "The depletion deduction" allows an owner or operator to account for the reduction of a product's reserves. Types of depletion For tax purposes, the two types of depletion are percentage depletion and cost depletion. For mineral property, the method leading to the largest deduction is generally used. For standing timber, use of the cost depletion method is required. Depletion, for both accounting purposes and United States tax purposes, is a method of recording the gradual expense or use of natural resources over time. Depletion is the using up of natural resources by mining, quarrying, drilling, or felling. According to the IRS Newswire, over 50 percent of oil and gas extraction businesses use cost depletion to figure their depletion deduction. Mineral property include ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
