The electrokinetic potential between the surface of the colloid and any point in the mass of the suspending liquid is referred to as the surface potential. Ozone depletion and global warming potential for certain other foam plastic roof insulation products will not reach zero until 2010, unless manufac turers choose to convert to zero odp and zero gwp blowing agents prior to that date. The ozone layer refers to a region of earths stratosphere that absorbs most of the suns uv radiation. For each ods, this page provides the compounds atmospheric lifetime, ozone depletion potential ozone depletion potentiala number that refers to the amount of ozone depletion caused by a substance.
A global semiempirical ozone depletion potential may be defined solomon et al. Ozone layer depletion is simply the wearing out reduction of the amount of ozone in the stratosphere. Lnapl recovery is often a default or presumptive remedial objective in most regulatory programs. A critical link in protecting climate and the ozone layer. This product is drm protected and requires registration. The portion of the channel in a metal oxide fieldeffect transistor in which there are no charge carriers. The information given is free, as are most calls though some operators, phone. Knowledge of the zeta potential can reduce the time needed to produce trial formulations. Relative value that indicates the potential of a substance to destroy ozone gas as compared with the potential of chlorofluorocarbon11 cfc11 which is assigned a reference value of 1. It can be used to optimize the formulations of suspensions and emulsions. Odp values are used to provide a simple way to compare the relative ability of various ods to destroy stratospheric ozone. Ammonia is a natural refrigerant and a zero global warming potential gwp and a zero ozone depletion potential odp and requires less electricity, resulting in lower operating costs and efficiencies. A regular diode differs from a zener diode in the amount of doping.
Appendix b natural source zone depletion nszd appendix. Ozone depletion potential an overview sciencedirect topics. Ozone depletion potential odp the odp of a compound is defined as the ratio of the total amount of ozone destroyed by that compound to the amount of the ozone destroyed by the same mass of cfc11. This pdf converter saves you the trouble of finding, downloading and installing specialized software on your computer and allows you to access its features from anywhere in the world. Zeta potential is a physical property which is exhibited by any particle in suspension. Your first pictures show only the free moving things. Gradient method nomograms, described below, are useful tools for designing an nszd assessment program, predicting a range of potential results, and assessing and communicating results. You are right that a depletion region forms at the pn junction due to recombination, but the change in charge concentration near the junction also has another effect. Chapter 6ozone depletion and chlorine loading potentials. Chlorodifluoromethane r22, for example, has an odp of 0. Pn junction depletion region physics stack exchange. A little discussed but very important example is phosphate. Physics of semiconductor devices pn junction depletion width.
The electrostatic force forces the free moving thingies and their kernels together. With gods blessings, she is bringing healing to those fortunate enough to cross her path. The potential and limitations of the ndecane hydroconversion as a test reaction for characterization of the void space of molecular sieve zeolites. Chapter 14 depletion of resource what depletion of resources is. 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 ozone layer is mainly found in the lower portion of the stratosphere. Zeolites vol 6, issue 5, pages 322416 september 1986. Introduction numerous sites across the country are impacted with light, nonaqueousphase liquids lnapls. This recombination of electrons and holes produces a narrow region at junction called depletion layer. Few years ago ozone holes are also discovered in arctic region. In the depletion layer all the atoms are complete and have no free electrons left within. Ozone depletion potential represents the potential of depletion of the ozone layer due to the emissions of chlorofluorocarbon compounds and other halogenated hydrocarbons. These conditions may change where aerobic or anaerobic degradation processes dominate and influences the lnapl mass loss rate. Apr 14, 2009 its free to download 10 years ago reply are you sure you want to.
Ozone layer the ozone layer is basically naturally occurring gas in the region of stratosphere where ozone particles are accumulated 2. The odp is the ratio of the impact on ozone of a chemical compared to the impact of a similar mass of cfc11. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Ozone depletion potential is measured relative to cfc11 and it represents the amount of ozone destroyed by emission of a vapor over its entire atmospheric lifetime relative to that caused by the emission of the same mass of cfc11.
Physics of semiconductor devices pn junction depletion. If you have pregion on the left and nregion on the right then electrons would have to climb a potential barrier going from n to p move uphill. Pdf futuristic health today download read online free. Ozone holes are first discovered in antarctica in 1970. Cfc 11, or r11 has the maximum potential amongst chlorocarbons because of. Unlike pollution, which has many types and causes, ozone depletion has been pinned down to one major human activity. The book confronts these multidimensional risk assessments headon and will catalyse the important interdisciplinary and integrated approach that is the new paradigm now required for environmental and public health research. Why is the depletion region thin in zener breakdown when it. Doping is the addition of impurity to pure silicon. When we get to x0 we encounter the large negative deltafunction of negative charge at the edge of the depletion region.
Ppt ozone layer depletion authorstream presentation. Numerous sites across the country are impacted with light, nonaqueousphase liquids lnapl. Thus, a substance with odp of 2 is twice as harmful as cfc11. Pdf depletion potentials in highly sizeasymmetric binary. Ozone depletion potentials odps were a very important measure in the formulation of the montreal protocol and its amendments. Ozone depletion and global warming potential of thermal insulation. Amount of damage to the ozone layer a given chemical can cause compared to trichlorofluoromethane, which is given a value of 1. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. It is estimated that 10% of the worlds population will face the consequences of ozone depletion this year and these numbers were continue to. Depletion zone article about depletion zone by the free. Dry powder inhalers, propellantfree aqueous metereddose inhaler, soft mist.
Absent this added layer of protection we humans will be susceptible to various forms of cancer due to over radiation and eye problems such as cataracts. The cie biology 2 teachers digital edition includes a full nonprintable pdf version of the workbook. Due to depletion of ozone uv rays are penetrating in troposphere and leading. Suggested model answers are included on each page in an interactive hideshow format, making it suitable for use with an interactive whiteboard. Ozone depletion potential article about ozone depletion. Footscray, victoria table 1 global warming and ozone depletion potential of anaesthetics chemical formula lifetime yrs isoflurane chf. It is estimated that 10% of the worlds population will face the consequences of ozone depletion this year and these numbers were continue to rise as time progresses. Reference diagram for nszd mass depletion processes. We must remember than silicon is a semiconductor, so when compared to a good c.
Why is the depletion region thin in zener breakdown when. Urban ozone formation potential is expressed relative to ethene. Key nszd processes include volatilization, dissolution, and biodegradation. Cfc 11, or r11 has the maximum potential amongst chlorocarbons because of the presence of three chlorine atoms in the molecule. Presentations ppt, key, pdf logging in or signing up. Ozone depletion is the process of destruction of the ozone layer which can cause adverse effects on the living forms by many pollutants releases out from the vehicles, industries etc. Since the charge density is zero all the way up to the edge of depletion region, gauss tells us that the electric field can not change here either. The ozone depletion potential odp of a chemical compound is the relative amount of degradation to the ozone layer it can cause, with trichlorofluoromethane r11 or cfc11 being fixed at an odp of 1.
One of the main reasons for the widespread concern about depletion of the ozone layer is the anticipated increase in the amounts of ultraviolet radiation received at. What are the depletion width in the nregion, the depletion width in the pregion, and the builtin potential at 300k. We use your linkedin profile and activity data to personalize ads and to show you more relevant ads. Odp is defined as the integrated change in total ozone per unit mass. Unfortunately, lnapls have historically posed a significant challenge to site. Depletion potentials in highly sizeasymmetric binary hardsphere mixtures. This timeline highlights the average area of the ozone hole between september 7th and october th as observed by nasa spacedbased instruments see colored bars and scale. Comparison of simulation results with theory douglas j. Ozonedepleting substances ozone layer protection us epa. Evaluating natural source zone depletion at sites with lnapl.
Ozone depletion over india with so much worry about the rapid ozone depletion taking place in various parts of the earth, indian scientists are closely monitoring the ozone layer over india for possible depletion trends. Climate change and vectorborne diseases introduction the vectors and their diseases epidemic potential climate effects malaria prevalence climate. 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. This table provides up to date internationally recognised data on the ozone depletion potential and global warming potential of the gases, as well as an easy. Ozone layer is also naturally broken down but there is a balance between its formation and natu. Almost all physical, chemical, biological and other activities are responsible for environmental degradation. Why doesnt the whole pn junction become depletion region. Book description understanding how complex ecological and climatic change can influence human health is the new challenge before us. Acidification potential an overview sciencedirect topics.
The data analysis resulted in the formation of a limited number of models concerning the distribution and role of ozone in the atmosphere, the ozone depletion process, and the consequences of ozone depletion. Find out information about ozone depletion potential. Causes of ozone layer depletion and its effects on human. The depletion region acts like a wall between ptype and ntype semiconductor and prevents further flow of free electrons and holes.
There is shortage of drinking water and water for irrigation. Ego depletion 8 what causes depletion overall, and consistent with the definition of selfcontrol given above, researchers have found that anytime an individual overrides, inhibits, stops, or changes a mood, urge, thought or behavior, it can lead to depletion and hence poorer selfcontrol. Ozone depletion potential how is ozone depletion potential. The ozone depletion potential odp of a compound is a simple measure of its ability to destroy stratospheric ozone. Wikimedia because of the accumulation of electrons on the p side of. Egodepletion 8 what causes depletion overall, and consistent with the definition of selfcontrol given above, researchers have found that anytime an individual overrides, inhibits, stops, or changes a mood, urge, thought or behavior, it can lead to depletion and hence. Appendix bnatural source zone depletion nszd appendix executive summary. Ozone layer depletion is one of the major environmental issues which is getting thinner day by day as a result of increasing pollution. Lnapl natural source zone depletion nszd occurs through the combined action of natural processes that reduce the mass of lnapl in the subsurface. Almost always the ozone has only been correlated with the hole in the ozone layer and the damages it has caused to the environment.
The richness of the ozone layer that makes the hole so significant and the science behind the hole is far less popular. The views of forty primary students about ozone and its depletion were recorded through individual, semistructured interviews. Since 2000 rate of ozone depletion is increasing 0. Physics of semiconductor devices pn junction depletion width problem a silicon pn diode has a doping of n d 81015 1 cm3 and n a 210 16 1 cm3. The nomograms are for screeninglevel purposes only. It is also an aid in predicting longterm stability. Understanding the depletion region is key to explaining modern semiconductor electronics. One of the main reasons for the widespread concern about depletion of the ozone layer is the anticipated increase in the amounts of ultraviolet radiation received at the surface of. The only elements left in the depletion region are ionized donor. Life cycle assessment of first, secondgeneration, and microalgae biofuels. Surface potential the relationship between zeta potential and surface potential depends on the level of ions in the solution. Futuristic health today utilizes practical techniques with the application of nutritional supplements, positive affirmations, praying it forward, and dietary. Ozonedepleting substances 2015 european environment agency. As the depletion zone edge moves back towards the pn junction, it meets the outgoing ionized carrier pulse, which is then collected earlier than in the smallsignal case where there is no depletion zone edge modulation.
Futuristic health today is the story of one womans journey to heal herself through holistic remedies. The depletion region is also called as depletion zone, depletion layer, space charge region, or space charge layer. Industries that manufacture things like insulating foams, solvents, soaps, cooling things like air. Childrens models of the ozone layer and ozone depletion. The montreal protocol has had great success in reducing the production and use of a number of known ozone depleting substances. To over come this the electrons require extra energy, which is absent and the absorption stops. Natural source zone depletion unsaturated zone permeability, grain size, heterogeneity, consolidation, and soil moisture affect the effective diffusivityof volatilized lnapl and biogenic gases. The chlorofluorocarbon and the halons are potent ozone depletors. The ozone depletion potential odp of a chemical compound is the relative amount of. Potential ozone depleting substances nordic cooperation. The ozone layer was discovered in 19 by the french physicists charles fabry and henri buisson.
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