
	Where results make sense

Topic: Depletion zone

In the News (Wed 15 Oct 08)

Richard Garriott

Janet Jackson

Iron Man

Steve Jobs

Atletico Madrid

Sarah Palin

Princeton University

Jon Lester

Nobel Prize

Angel Island

	Depletion region - Wikipedia, the free encyclopedia
		In semiconductor physics, the depletion region, also called depletion layer or depletion zone, is an insulating region within a conductive, doped semiconductor material where the charge carriers have been swept away through recombination.
		The depletion region forms across the P-N junction when the junction is in thermal equilibrium, i.e.
		Understanding the depletion region is key to explaining modern semiconductor electronics : the operation of diodes, bipolar junction transistors, field effect transistors, and variable capacitance diodes rely on depletion region phenomena.
	en.wikipedia.org /wiki/Depletion_zone (342 words)

	Articles - Depletion zone (Site not responding. Last check: 2007-11-06)
		Whereas P-doped and N-doped semiconductors are conductors, the Depletion Zone is an insulator.
		Depletion zone forms across the PN junction when the junction is at zero or reverse bias.
		The existence and shape of Depletion Zones is easily controlled by electric fields, usually in the form of voltages applied to the electrodes contacting the semiconductor.
	www.kamero.net /articles/Depletion_zone (297 words)

	Ch04 (Site not responding. Last check: 2007-11-06)
		The estimated rate of forest depletion in the tropical zone in the decade 1981 to 1990 was 15.4 million hectares per year, significantly greater than the annual depletion of 11.4 million hectares assessed in the decade 1971 to 1980.
		The total area occupied by the dry forest zone is roughly one-third that of the rain forest zone but depletion has reached an advanced stage, especially in Asia where only 15 percent of the zone is now forested.
		Depletion of these forests has reached an advanced stage, especially in Asia and Africa, and is continuing at a rapid rate.
	www.fao.org /docrep/T0829E/T0829E04.htm (3347 words)

	Irrigation Scheduling: The Water Balance Approach
		The second parameter is the effective root zone of the crop, which is the soil depth of the roots.
		The management allowable depletion (MAD) is the percent of available soil water that is allowed to be depleted before irrigation is applied.
		For example, 10 percent depletion means that the soil profile is 90 percent full, and the soil coefficient is 0.97.
	www.ext.colostate.edu /pubs/crops/04707.html (1641 words)

	Ecosystem Description - Hypoxia in the Gulf Of Mexico
		The rate of depletion of oxygen during processes that decompose the fluxed organic matter exceeds the rate of production and resupply from the surface waters, especially when waters are stratified.
		Throughout its distribution, the impact of hypoxic bottom waters is exacerbated by the release of toxic hydrogen sulfide from sediments (Harper et al., 1981, 1991).
		The severity and duration of oxygen depletion in the northern Gulf of Mexico depend, at least partially, on the amplitude and phasing of discharge from the Mississippi and Atchafalaya Rivers (Justic et al., 1993; Rabalais et al., 1996, 1998, 1999).
	www.csc.noaa.gov /products/gulfmex/html/rabalais.htm (3079 words)

	Environmental effects of ozone depletion: Interim Summary, August, 2000
		However, the vertical extent of depletion in the Arctic was slightly less than in the record-setting years of 1993, 1995 and 1996; and the peak integrated column ozone loss in 2000 was less than in those years.
		Interactions between global warming and ozone depletion could delay ozone recovery by more than a decade, and this topic remains an area of intense research interest.
		depletion, as well as both increases and decreases due to tropospheric cloud cover, scattering and absorbing aerosols, and pollutant gases.
	www.gcrio.org /ozone/unep2000summary.html (2965 words)

	Patent 4929993: Hall element device with depletion region protection barrier
		A depletion region, depleted of mobile charge, is located between the surface and the active zone to provide isolation for the active zone, so that the Hall device output is linear and independent of changes in external temperature.
		In all cases, a depletion region is provided between the active zone 7 and the surface of the Hall element 22 which, as already mentioned, covers the active zone 7 of Hall element 22, if possible completely at the top (and in some embodiments on the bottom as well).
		The depletion region insulates and completely protects the active zone 7 of Hall element 22 so that it is not necessary to provide an insulating layer formed from silicon oxide that is in direct contact with the active zone 7 of Hall element 22.
	www.freepatentsonline.com /4929993.html (7035 words)

	P-n junction - Enpsychlopedia (Site not responding. Last check: 2007-11-06)
		This nonconducting layer, called the depletion zone, occurs because the electrical charge carriers in doped n-type and p-type silicon ( electrons and holes, respectively) attract and eliminate each other in a process called recombination.
		With increasing bias voltage, eventually the nonconducting depletion zone becomes so thin that the charge carriers can tunnel across the barrier, and the electrical resistance falls to a low value.
		At the middle of the junction of the p-n material, a depletion region is created to stand-off the reverse voltage.
	www.grohol.com /psypsych/wiki/P-n_diode (890 words)

	Patent 5248893: Insulated gate field effect device with a smoothly curved depletion boundary in the vicinity of the ...
		wherein the gate and concave surface portion are curved at least in the vicinity of the channel-free zone such that a smoothly curved depletion zone boundary will develop in the vicinity of the channel-free zone when the transistor is in the turned-off state.
		In addition, voltage V.sub.G is supplied to the gate 1 causing a depletion layer 20 with a trapezoid configuration to be formed under the gate 1 and between the depletion layers 29.
		Also, a depletion layer 10 is formed along the concave between the source 4 and the drain 5.
	www.freepatentsonline.com /5248893.html (2676 words)

	The P-N Junction
		A space charge builds up, creating a depletion region which inhibits any further electron transfer unless it is helped by putting a forward bias on the junction.
		The electrons which had migrated across from the N to the P region in the forming of the depletion layer have now reached equilibrium.
		Other electrons from the N region cannot migrate because they are repelled by the negative ions in the P region and attracted by the positive ions in the N region.
	hyperphysics.phy-astr.gsu.edu /hbase/solids/pnjun.html (460 words)

	Dopamine depletion impairs precursor cell proliferation in Parkinson disease - Nature Neuroscience
		Cerebral dopamine depletion is the hallmark of Parkinson disease.
		Experimental depletion of dopamine in rodents decreases precursor cell proliferation in both the subependymal zone and the subgranular zone.
		Consistently, the numbers of proliferating cells in the subependymal zone and neural precursor cells in the subgranular zone and olfactory bulb are reduced in postmortem brains of individuals with Parkinson disease.
	www.nature.com /cgi-taf/DynaPage.taf?file=/neuro/journal/v7/n7/abs/nn1265.html (295 words)

	Platinex Big Trout Lake Details
		PGE mineralization was encountered in both the ultramafic unit of the East Zone and the anorthosite unit of the West Zone.
		Cu/Pd ratios at the base of the intrusion indicate that the basal ultramafic cycle is depleted in PGE and that the PGE plus copper and nickel may have been scavenged from the intrusion by a sulphide body during emplacement of the intrusion.
		In the West Zone, PGE mineralization occurs as 0.2 g/t to 1.6 g/t combined PGE over 20m to 60m, with Pt:Pd ratios generally in the range from 1:1 to 1:1.5.
	www.platinex.com /bigtroutlake.htm (3147 words)

	Olympus Microscopy Resource Center: Physics of Light and Color - Introduction to Light Emitting Diodes
		In the depletion zone, a static charge is established that inhibits any additional electron transfer, and no appreciable charge can flow across the junction unless assisted by an external bias voltage.
		With application of a sufficiently high voltage, the electrons in the depletion region are elevated in energy to dissociate with the holes, and to begin moving freely again.
		Manipulation of the interaction between electrons and holes at the p-n junction is fundamental in the design of all semiconductor devices, and for light emitting diodes, the primary design goal is the efficient generation of light.
	www.olympusmicro.com /primer/lightandcolor/ledsintro.html (8197 words)

	Prev
		A large crystal is needed to produce a depletion zone whose size allows detailed measurement of concentration gradients.
		The salt concentration in the salt chamber was adjusted using on-ground experiments and a computer simulation of mass transport inside the APCF so that, at the protein chamber, high supersaturation would never be reached; the system would always be in the metastable region to avoid nucleation while assuring the growth of the seed.
		A large and isolated depletion zone was expected to appear around the growing crystal.
	lec.ugr.es /sts95/expA.htm (574 words)

	Ozone Depletion: What Is It Doing to the Ecosystem?
		Minimal attention, however, is being paid to the potentially most devastating effect of stratospheric ozone depletion, the impact on the global ecosystem.
		In the summer of 1994, I was part of a research team looking at impacts of ozone depletion on the fragile freshwater ecosystems of Canada's High Arctic for the first time.
		The need to make research into the ecosystem impacts of ozone depletion a global research priority cannot be overstated.
	perc.ca /PEN/1995-06/round.html (639 words)

	Chapter 8 - ETc under soil water stress conditions (Site not responding. Last check: 2007-11-06)
		Rainfall, irrigation and capillary rise of groundwater towards the root zone add water to the root zone and decrease the root zone depletion.
		The amount of water transported upwards by capillary rise from the water table to the root zone depends on the soil type, the depth of the water table and the wetness of the root zone.
		of the root zone increases above this critical threshold value, the yield is presumed to begin to decrease linearly in proportion to the increase in salinity.
	www.fao.org /docrep/X0490E/x0490e0e.htm (4985 words)

	Ground Water Depletion and Conservation (Site not responding. Last check: 2007-11-06)
		May be easier to settle the land issues than the water issues, since much of the water supply in the area comes from underground and can't be seen directly.
		Lies beneath the zone of aeration ( vadose zone or soil moisture).
		It fluctuates with topography (may be higher than elevation of land such as at a lake) and with rate of recharge (infiltration from surface plus migration in from side) versus rate of discharge (loss due to pumping and migration out).
	www.rider.edu /~husch/geo113groundwaternotes.html (1272 words)

	Prev
		As the crystal moves, the depletion zone around the large crystal changes from slightly deformed in the left interferogram to severely distorted in the middle to almost inexistent in the right one.
		On a larger scale, the relatively fast crystal movements observed in figure 1 (induced by these large g-jitters) do break the symmetry of the depletion zone around the growing crystal as expected whenever the velocity of flow of macromolecules towards the crystal face is slower than the rate of motion of the crystals.
		For the analysed experiment the thickness of the depletion zone is between 1 and 1.4 mm and the diffusivity of the ferritin is D = 3.2 10
	lec.ugr.es /sts107/expB.htm (809 words)

	SCIENCE, VOL. 255
		Results from a 6-week cruise (Icecolors) in the marginal ice zone of the Bellingshausen Sea in austral spring of 1990 indicated that as the O3 layer thinned: (i) sea surface and depth-dependent ratios of UVB irradiance (280 to 320 nanometers) to total irradiance (280 to 700 nanometers) increased and (ii) UVB inhibition of photosynthesis increased.
		In spite of the mounting evidence, the extrapolation of these findings to allow prediation of impacts on the dynamics and vitality of natural, mixed communities of marine organisms is uncertain ( 10, 11, 38-42), and estimated impacts to the Antarctic marine ecosystem have ranged from insignificant to catastrophic ( 43-45).
		As a consequence, stratospheric O3 depletion leads to a dramatic increase in damaging UVB irradiance, Q UVB, whereas the corresponding irradiance in the UVA, Q UVA, and in the PAR, Q PAR, remain relatively constant.
	www.ciesin.org /docs/011-450/011-450.html (5081 words)

	Solutions Lighting - How do LEDs work (Site not responding. Last check: 2007-11-06)
		In a depletion zone, the semiconductor material is returned to its original insulating state -- all of the holes are filled, so there are no free electrons or empty spaces for electrons, and charge can't flow.
		To get rid of the depletion zone, you have to get electrons moving from the N-type area to the P-type area and holes moving in the reverse direction.
		When the voltage difference between the electrodes is high enough, the electrons in the depletion zone are boosted out of their holes and begin moving freely again.
	www.solutionslighting.com /content/view/22/31 (650 words)

	Lake Erie 'Dead Zone' and Special Lake Erie Study
		USEPA Environmental Scientist, Paul Bertram, Ph.D. explains oxygen depletion in Lake Erie and the actions that USEPA is taking understand the problem.
		The severity of oxygen depletion varies from year-to-year, depending on water temperature and the thickness of the bottom layer.
		Although the long-term trend is downward, there hasn’t been any improvement since the late 1980s ( more on oxygen depletion in Central Lake Erie).
	www.epa.gov /glnpo/lakeerie/eriedeadzone.html (353 words)

	Chapter 5 Improving the model
		Together with the freeness of the depletion variables this is a way for the model to change ETa as desired.
		Again it has turned into a problem where root zone shortage only should take place if the root zone overcapacity is zero, thus the constraint to force the correct behavior is now straightforward.
		The persistent underestimation of depletion by the AIMMS model may lie in the fact that CROPWAT applies an "effective rainfall method", thus reducing the amount of rainfall.
	home.hetnet.nl /~krekelberg/chapter5.htm (4448 words)

	Physical Processes Affecting Natural Depletion of Volatile Chemicals in Soil and Groundwater -- Parker 2 (2): 222 -- ...
		NAPL depletion from the soil are 123, 52, and 31 yr, respectively.
		Vapor transport of trichloroethylene in the unsaturated zone: Field and numerical modeling investigations.
		Advective-dispersive transport of dense organic vapors in the unsaturated zone.
	vzj.scijournals.org /cgi/content/full/2/2/222 (3271 words)

	p-n Junction
		However, the negative charge of the acceptor's extra electron and the positive charge of the donor's extra proton (exposed by it's missing electron) tend to keep the depletion zone swept clean of free charges once the zone has formed.
		This causes a depletion zone to form around the junction (the join) between the two materials.
		The first thing to note is that the depletion zone is free of charge carriers and the electrons/holes find it difficult to cross this zone.
	www.mtmi.vu.lt /pfk/funkc_dariniai/diod (2688 words)

	Depletion width - Wikipedia, the free encyclopedia
		Depletion width is the width of the depletion zone in a p-n junction.
		The depletion zone within a semiconductor device is a region of nonconductor whose width can be controlled by e-fields, i.e.
		This page was last modified 12:52, 19 April 2005.
	en.wikipedia.org /wiki/Depletion_width (59 words)

	Results of laser measurements (Site not responding. Last check: 2007-11-06)
		Therefore, the curve for the p-side strip shows the increasing of the depletion zone with the bias voltage.
		The curve for the n-side strip shows an steep increase at full depletion voltage where the depletion zone reaches the n+ implant.
		In charge division measurements one investigates how the charge generated in the detector is divided among the strips neighboring the area of charge generation.
	wwwhera-b.mppmu.mpg.de /tstand/result.html (221 words)

	Journal of Soil and Water Conservation : Groundwater nitrate depletion in a swine lagoon effluent-irrigated pasture and ... (Site not responding. Last check: 2007-11-06)
		Start / J / Journal of Soil and Water Conservation / September 22, 1999 / Groundwater nitrate depletion in a swine lagoon effluent-irrigated pasture and adjacent riparian zone.
		Groundwater nitrate depletion in a swine lagoon effluent-irrigated pasture and adjacent riparian zone.
		This study was conducted to determine [NO.sub.3] accumulation and movement in the spray fields and riparian zone on a swine farm in eastern North Carolina, as well as effects of effluent irrigation on streams recharged by shallow groundwater flow.
	static.elibrary.com /j/journalofsoilandwaterconservation/september221999/groundwaternitratedepletioninaswinelagooneffluenti/index.html (289 words)

	Howstuffworks "How Dimmer Switches Work"
		This is because the electrons from the N-type material fill in holes along the border with the P-type material, creating depletion zones, insulated areas where there are few free electrons or holes (see this page for a full explanation of depletion zones).
		The voltage is strong enough to drive electrons from area a into the holes in area b, disrupting the last depletion zone.
		The depletion zones form again, and the triac loses its conductivity until the boost voltage builds up on the gate.
	www.howstuffworks.com /dimmer-switch4.htm (630 words)

	Numerical Analysis of the Depletion Zone Formation Around a Growing Protein Crystal -- TANAKA et al. 1027 (1): 10 -- ...
		Numerical Analysis of the Depletion Zone Formation Around a Growing Protein Crystal -- TANAKA et al.
		It is expected that a protein depletion zone and an impurity
		depletion zone are formed around a crystal during protein crystal
	www.annalsnyas.org /cgi/content/abstract/1027/1/10 (335 words)

Try your search on: Qwika (all wikis)