Effects of Water Pollution Essay Example

Effects of Water Pollution Essay Water Pollution and Its Effects The water pollution is very harmful to humans, animals and water life. The effects can be catastrophic, depending on the kind of chemicals, concentrations of the pollutants and where there are polluted. Below, we shall see a summary of the effects of water pollution. The effects of water pollution are varied and depend on what chemicals are dumped and in what locations. Many water bodies near urban areas (cities and towns) are highly polluted. This is the result of both garbage dumped by individuals and dangerous chemicals legally or illegally dumped by manufacturing industries, health enters, schools and market places. Death Of aquatic (water) animals The main problem caused by water pollution is that it kills life that depends on these water bodies. Dead fish, crabs, birds and sea gulls, dolphins, and many other animals often wind up on beaches, killed by pollutants in their habitat (living environment). Disruption of food-chains Pollution disrupts the natural food chain as well. Pollutants such as lead and cadmium are eaten by tiny animals. Later, these animals are consumed by fish and shellfish, and the food chain continues to be disrupted at all higher levels. Diseases Eventually, humans are affected by this process as well. People can get diseases such as hepatitis by eating seafood that has been poisoned. In many poor nations, there is always outbreak of cholera and diseases as a result of poor drinking water treatment from contaminated waters. Destruction of ecosystems Ecosystems (the interaction of living things in a place, depending on each other for life) can be severely changed or destroyed by water pollution. Many areas are now being affected by careless human pollution, and this pollution is coming back to hurt humans in many ways. We will write a custom essay sample on Effects of Water Pollution specifically for you for only $16.38 $13.9/page Order now We will write a custom essay sample on Effects of Water Pollution specifically for you FOR ONLY $16.38 $13.9/page Hire Writer We will write a custom essay sample on Effects of Water Pollution specifically for you FOR ONLY $16.38 $13.9/page Hire Writer

How to Teach the Past Simple to ESL Students

How to Teach the Past Simple to ESL Students Teaching the English past simple verb tense to ELL or ESL students is rather straightforward after youve taught the present simple. Students will be familiar with the idea of auxiliary verbs in the question and negative but not in the positive form. They will be able to convert to past simple using helping verbs as in: Does she play tennis? - Did she play tennis?We dont drive to work. - They didnt drive to work. Theyll also be happy to know that the verb conjugation always remains the same, no matter the subject of the sentence. IYouHeShe played tennis last week.ItWeYouThey   Of course, theres the issue of irregular verbs,  which  can be frustrating because they just have to be memorized and reinforced through practice. A sampling of these: be- was/werecatch- caughtspeak- spokeunderstand- understood Past Time Expressions The key to teaching the past simple effectively is making it clear from the beginning that the past simple is used when something begins and ends in the past. The use of appropriate  time expressions will help: last: last week, last month, last yearago: two weeks ago, three days ago, two years agowhen past: when I was a child, when she worked in New York Start by Modeling the Past Simple Begin teaching the past simple by speaking about some of your past experiences. If possible, use a mix of regular and irregular past verbs. Use time expressions to provide context. Its also a good idea to mix in some other subjects such as my friend or my wife to signal that there is no change in the conjugation of the past simple other than putting the verb into the past. I visited my parents in Olympia last weekend.My wife cooked a wonderful dinner yesterday.We went to a movie yesterday evening. Continue modeling by asking yourself a question and providing the answer. Where did you go last week?  I went to Portland yesterday.When did you have lunch yesterday? I had lunch at 1 oclock yesterday.Which level did you teach last month? I taught beginner- and intermediate-level classes. Next, ask students similar questions. Its a good idea to use the same verbs- for example: went, had, played, watched, ate- when asking questions. Students will be able to follow your lead and answer appropriately. Introduce Regular and Irregular Verbs Using the verbs youve introduced, quickly ask students the infinitive form for each verb. Which verb is went?  goWhich verb is cooked? cookWhich verb is visited? visit Which verb is had? haveWhich verb is taught? teach Ask students if they notice any patterns. ​Usually, a few students will recognize that many past regular verbs end in ‑ed. Introduce the idea that some verbs are irregular and must be learned individually. Its a good idea to provide an irregular verb sheet for their study and future reference. Quick drills, such as a past simple grammar chant, will help students learn irregular forms. When discussing past regular verbs, make sure that students understand that the final e  in ‑ed  is generally silent: listened - /lisnd/watched - /wacht/   BUT: visited - /vIzIted/   Introduce Negative Forms Finally, introduce the negative form of the past simple through modeling. Model the form to the students and immediately encourage a similar answer. You can do this by asking a student a question, then modeling a negative and a positive sentence. When did you have dinner yesterday?  (student) I had dinner at 7 oclock.Did he/she  have dinner at 8 oclock? No, he/she didnt have dinner at 8 oclock. He/she had dinner at 7 oclock. Resources and Lesson Plans to Practice the Past Simple Explaining the Past Simple on the Board Use a past tense timeline to visualize the idea that the past simple is used to express something that began and ended in the past. Review time expressions that are used in the past, including last week, last month, and last year; in dates; and yesterday. Comprehension Activities After students are familiar with the form, continue expanding their understanding of it, as well as irregular verbs, with comprehension activities. Using stories of vacations, listening to  descriptions of something that  happened, or reading news stories will help underline when the past simple is used. Pronunciation Challenges Another challenge for students will be understanding the pronunciation of the past forms of regular verbs. Explaining the idea of voiced and voiceless pronunciation patterns will help students understand this pronunciation pattern.

The Life and Adventures of Joaquin Murrieta Essay

The Life and Adventures of Joaquin Murrieta - Essay Example This is the case with Joaquin Murieta who despite being a bandit is also depicted as being an honorable man as seen in the manner in which he shows acts of kindness especially for those people who are marginalized or poor in society. An incident where Murieta is shown being kind is where he demands that a ferryman ferries his gang across a river and give him all his money (Ridge 64 - 65). When Murrieta realizes that the ferryman only has a hundred dollars, he tells him to keep his money and pays him the full costs of ferrying the gang across the river. In this way, Murieta is shown to be a man sensitive to the plight of the poor, and it is likely that it is as a result of his having been raised in an environment of poverty which forced him to come north to California in order to make his fortune. The portrayal of Murieta, despite being a bandit, is one where he is depicted as being a very likeable individual as seen through the way that most individuals in the towns he ventures into do not consider him a threat. Instead, he is a man who is quite well liked with friend in almost all towns he visits who often warn him of anyone who is hunting him. It seems that it is as a result of the numerous friendships that he has developed all across California that Murieta is always a step ahead of those who hunt him. As a person who is considered to be a hero, he is constantly being protected by his friends in various towns who do not wish him to be captured. His likeable nature is part of the characteristics that make him a hero because despite living in banditry, he is an individual who seeks to always do the right thing at all times. Murieta is shown to be a man who has a very complicated personality in such a way that while he kills, he only does so in self-defense or in situations where he has suffered betrayal from people that he

Legal Aspects of Health Care Case Study Example | Topics and Well Written Essays - 1000 words

Legal Aspects of Health Care - Case Study Example Dr. Andrews (doctor) owed the duty to Bobby with regard to treatment of his left hand (amputation). He amputated the wrong hand, thus violating his duty; which also led to Bobby's loss. In addition to elements of negligence, the action by Dr. Andrews is res ipsa loquitur (that is, it speaks for itself). So there can be no two opinions that the doctor committed negligence while treating Bobby; and can be held liable to pay the damages. The actions of Nurse Williams at City General Hospitals can be reviewed using EMTALA (Federal Emergency Medical Treatment and Labor Act). EMTALA was passed in 1986 to prevent hospitals from refusing to treat a patient coming to their emergency room; on grounds of not having enough money or insurance to pay for the treatment. The Act places two main obligations on hospitals (Lafferty, 2000): 2. If it can be established that the patient's condition is in fact, an emergency; the hospital must take steps to 'stabilize' the condition before the patient can be asked to contact any other hospital for detailed treatment. In the given case, a screening examination was not conducted to determine the severity of wounds. Although, Nurse Williams attended Bobby immediately and put towels on his wound, probably to stop the flow of blood; and may be this would be presented by the hospital in defense. Yet there is no evidence that any screening examination was carried out to ascertain if the condition can be classified as emergency; and any attempt to 'stabilize' the emergency condition other than above which can hardly be classified as an attempt to stabilize Bobby's condition. The delay thus caused, resulted in deteriora36tion of the injury, which ultimately resulted in amputation. Bobby and his parents can sue

Art as Part of Culture Poses as an Obstruction for Globalisation Assignment

Art as Part of Culture Poses as an Obstruction for Globalisation - Assignment Example The definitions of art and culture are seemingly contrasting to the definition of globalisation, which in turn is defined as the compression and stretching of geographical spaces resulting to a borderless economy characterized by technology, information exchanges, knowledge economy and capital flow thus breaking down the barriers between nations expanding trade opportunities, eliminating monopolies and protectionist policies. (Mullard 83) Globalisation was generally perceived in a negative light more specifically on the economy of a nation. On the aspect of culture, adverse effects of globalization anticipated by nations are the corruption of a nation’s principles, loss of national identity and values as well as a threat to national security. These worries, however, are contested by explanations that the seemingly adverse effect of corrupting the nation’s principles would need the constant reminder of the importance of a nation’s heritage and culture as well as promoting national pride. Concerning national security, this serves as a challenge to improve safety measures of a nation. The definitions of art and culture that generally point towards the individuality of a nation have some disparities with the purpose of globalization to create one nation, which in some ways may need to intermingle some of the cultural differences among nations and in the process some of these cultural values may be compromised. In Hou Hanru’s statement saying, â€Å"To promote cultural difference and hybridity in contemporary art, one must first and foremost consider the need to create alternative contexts.† (Mullard 37) globalization in art does not require compromising a nation’s heritage instead, some alternative approach can be done to still preserve distinct cultures while building cultural crossbreeds in the art that are acceptable for diverse nations. Through ages, art has significantly depicted a country’s identity and rich culture.

Fill Factor Analysis of Organic Solar Cell

Fill Factor Analysis of Organic Solar Cell Rashmi Swami, Rajesh Awasthi, Sanjay Tiwari Abstract Solar cell is a device used to convert light into electricity. It can be made by organic and inorganic materials. Its most important parameters are open circuit voltage, short circuit current, fill factor and conversion efficiency. This paper is based on the analysis of factors that affect the fill factor of organic solar cell using MATLAB. Fill factor is calculated using conventional organic solar cell model without series and shunt resistances and constant light generated current for two different cases –first using Exponential dark characteristic and second using Polynomial dark characteristic. We get for exponential V-I relationship increase in ideality factor n, will reduce the fill factor and for polynomial V-I relationship increase in m will increase fill factor. A large dependence of light generated current Iph on increasing applied voltage would cause a significant drop in fill factor. Increase or decrease in an additional factor would accordingly change fill factor. Dark current can be varied in two ways, one by varying mobility and other by varying injection barrier heights. In both the cases fill factor increases proportionately with . Keywords – Organic solar cell, fill factor, ideality factor, open circuit voltage, HTL, ETL. Introduction Bilayer organic solar cell as shown in fig. 1(a) is a device in which thin layer of organic material (donor and acceptor) is used between electrodes to convert light into electricity. This work is completely based on bilayer structure of organic solar cell as shown in fig.1(a) in which poly(9,9-dioctylfluorene-co-bis-N,N-(4-butylphenyl)-bis-N,N-phenyl-1,4phenylenediamine) (PFB) is organic donor/HTL and poly(9,9-dioctylfluorene-co-benzothiadiazole) ( F8BT) is organic acceptor/ETL. Fig. 1(b) shows simplest conventional organic solar cell model without series and shunt resistances. Open circuit voltage, short circuit current, fill factor and efficiency are four important parameters of OSC. FF = Vmax Imax / VOC ISC When Vm= VOC and Im= ISC then (FF)max=1. For a good photo-voltaic device, all three factors FF, VOC, ISC should be large so that it can deliver large output power for the same incidental optical power. (b) Fig. 1 : (a) Bilayer organic solar cell structure. (b) Conventional organic solar cell model without series and shunt resistances. Simulation Model and Analysis of Fill Factor Two cases have been studied, one where dark characteristic is exponential like p-n junction and other where dark characteristics is polynomial like in space charge limited devices. 1.2.1Exponential Current Voltage Relationship – In this model, dark characteristic is assumed to follow exponential current voltage relationship and Iph is assumed to be constant. (1) where n is ideality factor and Vth is thermal voltage, Iph is light generated current, Id is dark current and I is net output current. Total output measured current can be written as a function of photo-generated current and dark current. (2) Output power of organic solar cell when it is operating at voltage V and giving current I- If maximum power is obtained at voltage Vm, , here assuming (3) Here y exp(y) is Lambert’s W function (4) and (5) At VOC net output current will be zero. At this condition eq. (2) will give (6) 1.2.2 Polynomial Current-Voltage Relationship In this case it is assumed that dark current depends on the applied voltage in the following manner- (7) Where K is constant and . (8) If photovoltaic is operated at voltage V and output current is I, output power will be- To calculate fill factor, one needs to find out the maximum power which photo-voltaic cell can supply. If maximum power is delivered at voltage Vm This will give, (9) and (10) At VOC net output current will be zero. At this condition eq. (8) will give (11) and (12) 1.2.3 Effect of Dark Current on Fill Factor – Simulation using 1D drift-diffusion electrical modeling of bilayer OSC in MATLAB is done. We obtained that the dependence of light generated current on the applied voltage means that fill factor would depend on it as well besides shape of dark characteristics. An estimate of variation of light current can be obtained by taking ratio of its value at short circuit and open circuit condition – At 0 volt, At VOC, i.e. The ratio is a measure of how drop in Iph with the voltage. This ratio can be written as – Thus shows an additional factor that would affect fill factor. As this factor increases or decreases, the fill factor should accordingly change too. Results and Conclusions Eq. (3) suggests that as ideality factor n is changed, keeping reverse saturation current I0 and photo-generated current Iph constant, Vm changes in such a manner that (Vm/n) remains constant. So Im will also be constant as it is a function of (Vm/n). From eq. (6) open circuit voltage is also changes with ideality factor n such that (VOC/n) remains constant. It follows from the above reasoning that (Im/ISC) and (Vm/VOC) will be unchanged if n will vary keeping the reverse saturation current constant. Hence as ideality factor n varies keeping the reverse saturation current I0 constant, fill factor of the device will remain unchanged. Though if open circuit voltage (VOC) assumed to be constant by varying reverse saturation current I0 as ideality factor n changes, fill factor will change accordingly. Assuming Iph to be 1 mA-cm-2, I0 to be mA-cm-2 and ideality factor n to be 1, open circuit voltage and fill factor come out to be 1.25 volts and 0.9 respectively. Taking Iph and VOC constant, the variation of fill factor with ideality factor n is shown in fig. 2. We get that increase in the value of ideality factor n, will reduce the value of fill factor Fig. 2 : Variation of fill factor with ideality constant n. open circuit voltage and light generated current are taken to be constant as 1.25 V and 1 mA-cm-2 respectively. Eq. (12) shows that fill factor is a function of m. Variation of fill factor with m is shown in fig. 3. For m = 1, FF = 0.25. As m increases fill factor also increases and approaches to 1. However, FF will become only 1 when m is infinity. In this case also, m is a measure of the sharpness of the characteristic curve. As m increases, I-V curve becomes increasingly sharper resulting in a high fill factor. For polynomial dark characteristic with constant light generated current we get that increase in m will increase fill factor which approaches to 1 Fig. 3 : Variation of fill factor with m. fill factor approaches to 1 as m becomes larger and larger. Simulation results revealed in fig. 4 show that light generated current Iph is a function of applied voltage, means FF would depend on it as well besides shape of dark characteristic. A large dependence of Iph on increasing applied voltage would cause a significant drop in FF. Increase or decrease in an additional factor would accordingly change fill factor. Dark current can be varied in two ways, one by varying mobility and other by varying injection barrier heights. In both the cases fill factor increases proportionately with as shown in fig. 5 and fig. 6. Fig. 4 : Dependence of light generated current on the applied voltage. and are the hole and electron mobilities respectively. and are the injection barriers at anode and cathode respectively. Fig. 5 : Variation of fill factor with for 0.1eV and 0.3eV injection barrier heights. Different points have been obtained by changing mobility. Fig. 6 : Variation of fill factor with for carrier mobilities and . Different points have been obtained by changing injection barrier height. References J. A. Barker, C. M. Ramsdale, and N. C. Greenham, â€Å"Modeling the current-voltage characteristics of bilayer polymer photovoltaic devices†, Physical Review B 67, (2003), 075205. D. P. Grubera, G. Meinhardtb and W. Papousekc, Modelling the light absorption in organic photovoltaic devices, Solar Energy Materials and Solar Cells, 87, (2005), 215-223. J. Wagner, T. Fritz, and H. Bottcher, Computer modelling of organic thin film solar cells exciton model of photocurrent generation, Physica Status Solidi A, 136, (1993), 423. Y. Roichman and N. Tessler, â€Å" Generalized Einstein relation for disordered semiconductors implications for device performance†, Appl. Phys. Lett., 80, (2002), 1948. J. C. Scott and G. G. Malliaras, â€Å"Charge injection and recombination at the metal-organic interface†, Chem. Phys. Lett., 299, (1999), 115. S. E. Shaheen, C. J. Brabec, N. S. Sariciftci, F. Padinger, T. Fromherz, and J. C. Hummelen,† 2.5 % efficient organic plastic solar cells†, Appl. Phys. Lett., 78, (2001), 841-843 B. K. Crone, P. S. Davids, I. H. Cambell and D. L. Smith, â€Å"Device model investigation of bilayer organic light emitting doide†, J. Appl. Phys., 84, (2000), 1974. P. W. M. Blom, M. J. M. de Jong and S. Breedijk, â€Å"Temperature dependent electron hole recombination in polymer light emitting diodes†, Appl. Phys. Lett., 71, (1997), 930. C. M. Ramsdale, J. A. Barker, A. C. Arias, J. D. MacKenzie, R. H. Friend and N. C. Greenham, â€Å"The origin of open circuit voltage in polyfluorene-based photovoltaic device†, J. Appl. Phys, 92, (2002),4266. B. Mazhari, â€Å"An improved solar cell circuit model for organic solar cells†, Solar Energy Materials Solar Cells, 90, (2002), 1021.

Analysis of M.I.A.s Paper Planes Music Video -- Music Analysis

There is one universal language: the language of music. Music has a special quality and ability to bridge both social and cultural divides. A proposed theory by Dr. Gray, Founder and Director of National Musical Arts’ BioMusic Program; describes music has been around longer than human-beings have. Music is the one thing human beings from various backgrounds can relate to. Every living creature would agree. Music is heard everywhere not just among humans, but in nature as well, through the twitting of birds, winds blowing, the soft sound of raindrops against a windowpane, the ocean waves moving back and forth and the hum of the ocean rushing in a sea shell. There is no escaping it; music lives in and surrounds us steadily. While there are countless songs which confer social or cultural consciousness, this paper will analyze and address the dynamics of M.I.A.’s â€Å"Paper Planes†, video. Stylistically, the paper will examine the artist point of view, the unique use of lyrical analysis and sound description in relation to its historical, social, political and/or cultural context. This essay will also trace the lyrical analysis and sound description of song and discuss how the elements (visually, sonically, and lyrically) interplay with the theme of immigration and/or violence. Known in the music genre as one of the â€Å"most provocative pop star of her age† (Sawyer, Pg. 1). Mathangi "Maya" Arulpragasam or M.I.A. by her stage name was born in London in 1975. At 6 months, her parents returned to their native land of Sri Lanka. Sri Lanka is an island which is located off the southern coast of the Indian in South Asia. M.I.A is considered one of the most controversial music artists of her time. Many agree that she has a unique way of com... ....com/wpdyn/content/article/2005/09/15/AR2005091500697_pf.html>. M.I.A., â€Å"Paper Planes,† 2007, [Lyrics], http://www.azlyrics.com/lyrics/mia/paperplanes.html Moraga, Cherrie, and Gloria Anzaldua. This Bridge Called My Back. New York: Kitchen Table Women of Color Press, 1984. N. pag. Print. â€Å"ONTD.com- Interview†, [2010] http://ohnotheydidnt.livejournal.com/45685085.html Reed, La Trina L. "La Trina’s Mixx Tape: A Literary look in." Los Angeles. 22 Mar. 2012. Essay. Sawyer, Miranda. "MIA: 'I'm here for the people'." The Observer 12 June 2010: 1+. Web. 25 May 2012. . Stetler, Carrie. "Violent references raise concerns in Sri Lankan pop star's 'Paper Planes'." Nj.com 8 Oct. 2008: 1+. Web. 20 May 2012. .