Ozone layer depletion causes, effects and solutions. It is also one of the prime reasons which are leading to global warming. Appendix b natural source zone depletion nszd appendix executive summary 1. Some of the most important of these linkages involve the way that ozonedepleting substances and greenhouse gases alter radia tion processes in the. Firstly, we have to ban the use of cfcs product as. Ozone holes are first discovered in antarctica in 1970. Life is protected from uv rays by stratospheric ozone layer which acts as a shield or sun screen 2. Natural source zone depletion nszd has emerged as an important concept within the realm of environmental remediation. Individual ozonedepleting substances are not equal in. Electromagnetic energy coming from the sun is absorbed by the earth, which. Ozone absorbs a band of ultraviolet radiation called uvb. Reactive halogen gases can then destroy stratospheric ozone, resulting in depletion of the ozone layer.
Physics of semiconductor devices pn junction depletion. In a depleted zone, the intensity of depletion depends on the type of fluid, type of drive used during drilling, drawdown pressure and production rate. Mar 21, 2020 ozone depletion, gradual thinning of earth s ozone layer in the upper atmosphere caused by the release of chemical compounds containing gaseous chlorine or bromine from industry and other human activities. What are the depletion width in the nregion, the depletion width in the pregion, and the builtin potential at 300k. 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. An introduction to depletionmode mosfets by linden harrison since the midnineteen seventies the enhancementmode mosfet has been the subject of almost continuous global research, development, and refinement by both the semiconductor industry and academia. Ozone depletion consists of two related events observed since the late 1970s. Because of the similarity to thermally induced sensitization for creating a chromium depletion zone adjacent to the grain boundary, chromium depletion arising from ris has been implicated as a likely cause of iascc, especially in oxidizing environments. Ozone layer is also naturally broken down but there is a balance between its formation and natu. Scientific assessment of ozone depletion montreal protocol. View ozone layer depletion research papers on academia. Appendix b natural source zone depletion nszd appendix. The latter phenomenon is referred to as the ozone hole.
Pdf on jan 1, 2001, md safiuddin and others published global ozone depletion. The energy level sketch above right is a way to visualize the equilibrium condition of the pn junction. Test your knowledge of ozone layer science and ozone depletion in this crossword puzzle. However, a number of manmade chemicals that contain fluorine, bromine and chlorine groups, called ozone depleting. Depletion of the ozone layer results in increased uv radiation reaching the earths. Microscopic animals harmed by excess ultraviolet uv 6. Cfcs destroy the ozone in the stratosphere 15 20 km above the earths surface ozone concentrations are measure in dobsen units, 1 dobsen unit represents 1 molecule of o 3 for every 1 billion air molecules ozone loss is greatest over antarctica where the ozone depletion has been recorded and is commonly referred to as the ozone hole. Semiconductor devices depletion zone initially, when a junction diode is formed, there is a unique interaction between current carriers. Ozone depletion free download as powerpoint presentation. Sep 30, 2019 ozone depletion is largely a result of manmade substances. Due to depletion of ozone uv rays are penetrating in troposphere and leading.
In addition, increased surface uv leads to increased tropospheric ozone, which is a health risk to humans. In the 1980s, scientists found evidence that the ozone layer was being depleted. Ozone is formed by photochemical reaction, followed by three body reaction. The ozone layer is a deep blanket in the stratosphere made up of comparatively high concentration of the ozone.
Pdf causes of ozone layer depletion and its effects on. Mineral nutrients such as phosphorus have very limited mobility in soils so that depletion zones where all the available nutrient has been utilised. This is understandable because of the documented effect of. Global warming is caused by the greenhouse effect, which is essential to life as we know it on planet earth. Ozone loss is greatest over antarctica where the ozone depletion has been recorded and is commonly referred to as the ozone hole. Ozone depleti on consists of two related events observed since the late 1970s. Other linkages between climate change and ozone depletion are related to the effect of increased levels of ultraviolet radiation on sundriven. Ozone is a colourless gas which is found in the stratosphere of our upper atmosphere. What are the principal steps in stratospheric ozone depletion caused by human. A close look at the evolution at the life on earth reveals that initially the.
Near the junction, electrons diffuse across to combine with holes, creating a depletion region. Ozone layer depletion is one of the major environmental issues which is getting thinner day by day as a result of increasing pollution. Ozone depletion facts and information national geographic. Ozone depletion would magnify all of the effects of uv on human health, both positive including production of vitamin d and negative including sunburn, skin cancer, and cataracts. Mad is the maximum amount of plant available water paw allowed to be removed from the soil before irrigation refill occurs 2. Nszd is being considered as a site closure option during later stages of active remediation of lnapl contaminated sites.
When ptype and ntype materials are placed in contact with each other, the junction behaves very differently than either type of material alone. Approximately 90% ozone is present in stratosphere at the height of 10 to 17 kilometer and is called ozone layer while remain ing 10% is present in troposphere 3. 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. Ozone depletion biology science fair project ideas.
Update on ozonedepleting substances odss and other gases of. The depletion region is also called as depletion zone, depletion layer, space charge region, or space charge layer. There are also springtime polar t ropos p heric ozone dep letion. B dobson inferred correctly that the cause of the warm stratosphere was heating by the absorption of ultraviolet solar radiation by ozone, and he set out to. Nj1, 062005 nj35 c irrigationrelated management factors managementallowed depletion levels it is essential to maintain available moisture in the soil within certain limits for good crop growth. Key nszd processes include volatilization, dissolution, and biodegradation.
This timeline highlights milestones related to the history of ozone depletion. The depletion region acts like a wall between ptype and ntype semiconductor and prevents further flow of free electrons and holes. Ozone depletion, gradual thinning of earth s ozone layer in the upper atmosphere caused by the release of chemical compounds containing gaseous chlorine or bromine from industry and other human activities. Why the hole in the atmospheric ozone layer above us. Natural source zone depletion nszd has emerged as a practical alternative for restoration of light non. Hence, we should be aware and actions must be taken to ensure that ozone layer is not destroyed. Apr 18, 2019 the ozone layer helps to protect life from harmful ultraviolet radiation. Worlds best powerpoint templates crystalgraphics offers more powerpoint templates than anyone else in the world, with over 4 million to choose from. Our powerpoint presentation about ozone depletion, its effects and its causes. Presence of ozone in the lower atmosphere is considered as a pollutant and a greenhouse gas. Natural source zone depletion nszd of light nonaqueous phase liquids lnapls includes partitioning, transport and degradation of lnapl components.
Unlike oxygen o2, ozone has a strong scent and is blue in color. Ozone layer depletion leads to decrease in ozone in the stratosphere and increase in ozone present in the lower atmosphere. The only elements left in the depletion region are ionized donor. The thinning is most pronounced in the polar regions, especially over antarctica. Ppt ozone layer depletion powerpoint presentation free to. Andresen, in structural alloys for power plants, 2014. A free powerpoint ppt presentation displayed as a flash slide show on id. Project report on ozone depletion environmental pollution. Since 2000 rate of ozone depletion is increasing 0. Stratospheric ozone depletion, ultraviolet radiation and. Solution on ozone layer depletion september 16 was voted the world ozone day in the year 1994 by the united nations general assembly. It contains high concentrations of ozone o3 relative to other parts of the atmosphere. 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. Semiconductor devices depletion zone tutorialspoint.
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 ozone layer is mainly found in the lower portion of the stratosphere. The ozone layer helps to protect life from harmful ultraviolet radiation. Ozone in the lower atmosphere contributes to global warming and climate change. Theyll give your presentations a professional, memorable appearance the kind of sophisticated look that todays audiences expect. Global warming and ozone layer depletion are two different problems see the sidebar misconceptions about global atmospheric change on page 95. Evaluating natural source zone depletion at sites with lnapl. Lnapl recovery is often a default or presumptive remedial objective in most regulatory programs. The third body m absorbs the excess energy liberated by the above reaction and there by stabilise the o 3 ozone molecule. But many researchers do not agree with these predictions,14 and express their.
Lnapl natural source zone depletion nszd occurs through the combined action of natural processes that reduce the mass of lnapl in the subsurface. It contains some videos and gif at thte end from an external source. Numerous sites across the country are impacted with light, nonaqueousphase liquids lnapl. This depletion makes humans more vulnerable to the uvb rays which are known to cause skin cancer as well as other genetic deformities. The ozone layer refers to a region of earths stratosphere that absorbs most of the suns uv radiation. Groundwater nszd rates vadose zone processes seem dominant biggest bang for the buck. Ozone gas is perceptibly blue in colour and has a characteristic pungent smell. Pdf there are many situations where human activities have significant effects on the environment. The demand for a particular mineral nutrient depends on plant internal requirements, while the supply of that nutrient primarily depends on its availability and mobility in soils russell 1977, marschner 1995. 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. Causes of ozone layer depletion and its effects on human. Pn junction one of the crucial keys to solid state electronics is the nature of the pn junction. Ozone o 3, an allotrope of oxygen, is poisonous to humans if breathed in, but is important to life in that it filters out or absorbs short wavelength ultraviolet radiation u. Ozone layer depletion essay sample new york essays.
You may print out the puzzle, the clues, and the words. Case study depletion of ozone in the atmosphere the work of g. Ozone layer depletion cause, effects, and solutions. The latter phenomenon is referred to as the o zone hole. Following is the list of some of the main ozone depleting substances and the sources from where they are released. As a result of its chemical composition, ozone is regarded as a special type of oxygen as it contains three oxygen molecules o3 as opposed to the usual two oxygen molecules o2. The ozone layer protects humans, animals, and plants from harmful ultraviolet rays. Chapter 3 crops part 652 irrigation guide 210vineh 652, ig amend.
Winner of the standing ovation award for best powerpoint templates from presentations magazine. These chemicals are found in cleaning agents, aerosols, insulating foam, and refrigerants. Appendix bnatural source zone depletion nszd appendix executive summary numerous sites across the country are impacted with light, nonaqueousphase liquids lnapl. Causes, effects and solutions of ozone layer depletion. Ozone depletion is largely a result of manmade substances. Find out what caused the ozone hole, and how the 1989 montreal protocol sought to put an end to ozone depletion. The world meteorological or ganization wmo, 1995 predicted that the depletion of the ozone layer peaked around 1998 and the layer would slowly recover by 2045 12. 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. Introduction numerous sites across the country are impacted with light, nonaqueousphase liquids lnapls. Ozone layer depletion causes, effects and solutions 7. Dear students, the team of jagran josh is presenting you a set of 10 questions based on ozone layer depletion. Specifically, current will flow readily in one direction forward biased but not in the other reverse biased, creating the basic diode. Mar 28, 2020 ozone depletion biology projects, biology science fair project ideas, biology topics for cbse school,icse biology experiments for kids and also for middle school, elementary school for class 5th grade,6th,7th,8th,9th 10th,11th, 12th grade and high school, msc and college students.
Nszd is a term used to describe the collective, naturally occurring processes of dissolution, volatilization, and biodegradation that results in mass losses of light nonaqueous phase liquid lnapl petroleum hydrocarbon constituents from the subsurface. Humans have introduced gases and chemicals into the atmosphere that have rapidly depleted the ozone layer in the last century. Ozone layer depletion is one of the most serious problems faced by our planet earth. Money and time are being spent on ozone repair, but the problem still exists. What are the causes and effects of ozone depletion. Increased surface evaporation of water and usually higher rates of transpiration are associated with high frequency irrigation. Ozone layer depletion is one of the major environmental issues which is getting thinner day by day as a. Presentation on ozone depletion linkedin slideshare. The main effect of ozone depletion is an increase in uvb rays reaching the earths surface causes. The assessment may be reproduced or excerpted, without. Ozone depletion is one of several factors, includ ing cloud cover and solar elevation, which affect ground level uv radiation.
Ozone depletion atmospheric ozone layer depletion is a serious problem currently facing the world. Ozone depletion ozone depletion chlorofluorocarbon. Ozone layer the ozone layer is basically naturally occurring gas in the region of stratosphere where ozone particles are accumulated 2. The layer of ozone gas is what which protects us from the harmful ultraviolet radiations of the sun. Ozone science crossword puzzle ozone layer protection. Unfortunately, lnapls have historically posed a significant challenge to site. Ppt ozone layer depletion powerpoint presentation free.
The chlorofluorocarbon and the halons are potent ozone depletors. Ozone depletion is primarily caused by human activities. Les diablerets, switzerland by jeanpierre pommereau, june 2010. The ozone layer was discovered in 19 by the french physicists charles fabry and henri buisson.
In n type material, the electrons move readily across the ju. Ozone depleting substances are the substances such as chlorofluorocarbons, halons, carbon tetrachloride, hydrofluorocarbons, etc. 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. Ozone depletion and climate change environment canada. Why global mean surface temperatures began to rise around 1970 after having been relatively constant since 1945. One atom of this can destroy over 100,000 ozone molecules. The main effect of ozone depletion is an increase in uvb rays reaching the earths surface. Nearly 90% of earths ozone is in the stratosphere and referred to as the ozone layer. Appendix bnatural source zone depletion nszd appendix executive summary. Has the montreal protocol been successful in reducing ozonedepleting. The solid circles on the right of the junction represent the available electrons from the ntype dopant. There are also springtime polar tropospheric ozone depletion. 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.
B dobson and other scientists in measuring concentrations of chloride and ozone in the atmosphere g. Ozone science crossword puzzle ozone layer protection us epa. Few years ago ozone holes are also discovered in arctic region. This proves ozone depletion is a big issue that needs attention.
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