Advantages And Disadvantages Of Hydropower

Advantages And Disadvantages Of Hydropower The use of hydropower can date back to 7th millennium BC, were ancient Egyptian communities used hydropower for irrigation. In the contemporary society, hydropower still remains influential in the operation of mechanical devices such as watermills as well as energy or specifically electricity production, but the use of hydropower had becoming highly controversial due to its impacts on several geographical aspects. In this essay, I will be using several case studies to demonstrate the socio-economic, environmental factors of which the use of hydropower will have an impact on, in order for me to discuss and evaluate the advantages and disadvantage of using hydropower. The use of hydropower could lead to various types of socio- economical impacts in a region. For example, unlike fossil fuels, hydropower is a renewable energy source as it is not likely to run out, whilst un- renewable resources such as oil are predicted to run out between 2025 and 2070 (Senior, 2012). Hydropower enables a reliable supply of energy as long as the water supply remains stable. This is very important to maintain socio- economical stability as countries such as China uses up to 4692.8 TWh in 2011 according to the National Energy Commission. Without the contribution of hydropower, it would be more challenging for the Chinese to meets it demands for electricity. Since 48.6% of Chinas GDP is made up by industrial sector (Censky, 2011), the shortages of electricity supply could bring negative economic impacts across the region, as industrial sectors often requires electricity to produce products. Without sufficient electricity, the production of various products will be boug ht to a halt, thus reducing its income from manufacturing and trading. This could also affect the social aspect of the society, as trading decreases due to insufficient electricity, this could lead to negative multiplier effect as wages are likely to be reduced for workers, thus affecting peoples quality of life as their income reduces. However, some would argue that the relative importance and the contribution of hydropower is low. This was supported by the fact that even when fully functional, the Three Gorges Dam can only support about 1.7% of electricity demand in China (Wikipedia, 2012). This shows that the infrastructure in placed were not capable to catching up the demand for electricity in China, as the dam was predicted to provide 10% of Chinas required electricity(Wikipedia, 2012). However, the demand for it has increased more rapidly than originally planned. This also help illustrates that political decisions and inaccurate prediction and planning also plays in part in af fecting the number of advantages and disadvantages in the use of hydropower, as in this case, these factors lead to the reduction of effectiveness of hydropower. Besides that, hydropower had also bought more social- economical benefits into China. Although the full cost of the dam was estimated to be US$22.5 billion, it is expected that after 10 years of full operation, the full cost of the dam could be recovered as the generation of electricity will be cheap after the dam has been constructed (I.W.P. D.C., 2007). Until July, 2008, the State Grid Corporation and China Southern Power Grid paid 250 Yuen per MWH. After the construction of the damn, the cost of electricity for some province were reduced to 228.7 Yuen (China Three Gorges Coroperation, 2008). This is a benefit in terms of the social aspect as electricity became more affordable for people within some areas of China, thus this makes it an advantage which hydropower brings as people are likely to have to spent less income on electricity for appliances like heating, thus allowing them to have more disposable income for recreational activities, which potentially improve peoples quality of life. When looking further into social impacts, it is clear that some negative impacts and disadvantages were the results of using hydropower. For example, due to construction of the dam, official estimated that at least 1.2 million (Yardley, 2007) will be displaced and relocated (Yardley, 2007). More than 100 towns are submerged as a consequence, including Fuling and Wanxian (Gleick, 2008). Fourteen thousand hectares of agricultural land, along with 100 or more archaeological sites will be submerged (Gleick, 2008). These are the disadvantage of using hydropower by installing large scale energy generation units like the dam. These disadvantage include severe cultural, historical and social impacts. For example, towns like Fuling and other archaeological being submerged means that archaeological researches will not be able to carried out in the area in the future. Although reparations were given out when people are relocated, some would argue that the sentimental value and emotional attachm ent of these historical locations as well as their home time could never be replaced. Furthermore, the fact that people had to be relocated means that families and friends are likely to be separated during the relocation process due to the scale of the population. And again, although these social impacts are hard to measure to the full extent, but it is clear that these impacts will decrease the quality of life for the residents in those areas, and possibly leading to depression. However, it should be noted that this example may not apply to every case study related to hydropower. Small scale hydropower projects like watermills in rural areas will have less social impact on the local area, both negative and positive. For example, when building small scale watermills, the number of people displaced within a small area will be limited. Therefore, in this case, the disadvantages mentioned when looking at the Three Gorges Dam may not apply to small scale projects. Besides socio- economical impacts, the use of hydropower can also lead to environmental impacts. In comparison to burning fossil fuels, hydropower does not contribute directly to submission of greenhouse gases such as carbon dioxide while generating electricity. For example, in 1999, hydropower contributed 2659 TWh in global energy generation and this is 17.5 percent of the worlds total electricity produced for 1999 (Koch 2002). That amount of electricity would normally require the burning of 1595 million tonnes of coal, in which about 2 631.75 tonnes of carbon dioxide would be released into the atmosphere, thus contributing directly to global warming via the emission of greenhouse gas. Another example is the Three Gorges Dam in China. According to the National Development and Reform Commission of China, the Three Gorges Dam could reduce annual coal consumption by 31 million tonnes in energy production, which potentially reduced the emission of one million tonnes of sulphur dioxide. This is a major advantage as reduced of sulphur dioxide production could reduce acid rain on a national scale. This means that impacts of acid rain on the natural environment, such as the creation of acidic lakes and the disruption to soil chemistry would decrease and helps maintain biodiversity in natural environments. However, although various gas emissions has decreased potentially, the use of hydropower, particularly the use of dams and reservoirs can still create pollution and contribute to global warming. A study estimates that in 1990, the Curua-Una dam in Brazil generated more than three and a half times the amount of greenhouse gas by generating the same amount of electricity from oil (Fearnside, 2005). This was caused by the flooding of reservoirs, resulting in a build up of methane dissolved in water, as plant matters were left to rot and decay under water along with the sediments. Eventually, the methane would be released into the atmosphere when water passes through the dam after passing though the turbines. Since methane is a greenhouse gas which is also 21 times more heat trapping that carbon dioxide (Mark, 2012), the use of hydropower in terms of the use of dams and reservoir could be considered as a contributor to global warming and the generation of methane as a by-product of dams and reservoirs remains to be a disadvantage of using hydropower. Lastly, the construction of some infrastructure to utilise hydropower are known for causing negative impacts upon the environment as biodiversity is reduced as a result. For example, the percentage of forested area near the Three Gorges Dam decreased from twenty percent to less than ten percent between the years of 1950 and 2002 mainly due to deforestation when the dam was built (Chetham, 2004). Turbines used to generate electricity are also know for damaging fish and other freshwater animal species, further decreasing the biodiversity of the rivers (Xie, 2003). These impacts are strong evidence to demonstrate the disadvantage of using hydropower as a energy resource. In conclusion, using hydropower has its advantage to some extent. For example, it can be used to produce electricity as a more sustainable manner as hydroelectricity is a form of renewable energy. This means unlike fossil fuels and other un-renewable energy sources, electricity supply is not likely to run out, thus being able to provide continuous support to meet the demand of electricity required in socio-economical activities. However, the use of hydropower has also got its disadvantage, limitations and it could even overshadow its initial benefits. The limitation was demonstrated by the high initial set-up costs for more technological advanced, as well as efficient infrastructures and equipments to extract the power or potential energy from water, meaning that the use of hydropower will be limited in some regions, particularly in less economically developed regions like the Republic of Zimbabwe. Furthermore, disadvantages like the Curua-Una dam in Brazil generating large amount of greenhouse gases could mean that the use of hydropower, particularly in electricity generation could be questionable. Different factors and limitation, such as geographical location also plays a part in affecting the performance, as well as the efficiency of hydropower. The impacts also varies according to the scale, as well as the method and the infrastructure used to extract the energy. Therefore, it is over-simplistic to say that hydropower is completely advantages or disadvantageous based on the facts above, as the use of hydropower has both advantages and disadvantages.

Prejudice in To Kill a Mockingbird Essay -- essays research papers

  Ã‚  Ã‚  Ã‚  Ã‚  In the world people are always preconceived based on who they are or what they look like. Even though it isn’t as big of a problem in some areas as in others, we need to fight it. If we don’t then it will continue to get more serious and at times lead to death. In Harper Lee’s To Kill a Mockingbird, Alexandra tells her niece that she can’t play with a schoolmate simply because of his class. â€Å"‘You can scrub Walter Cunningham till he shines, you can put him in shoes and a new suit, but he’ll never be like Jem†¦Because—he—is—trash.’† (224). This prejudiced state of mind is the foundation for the plot events of the novel. By way of experiences, a young girl, Scout Finch, must learn about the part prejudice plays in the everyday life of Maycomb County. Through settlement patterns, justice, and social stratification Harper Lee reveals the ways of prejudice. The first instance of prejudice, settlement patterns, greatly affects how people of Maycomb are prejudged, not just where they lived, but also where they dwelled. The Ewells are considered the lowest class of Maycomb, aside from the blacks, which is shown by the fact that they live at the edge of the town, right next to the black people. â€Å"‘He would show me how where and how they lived. They were people, but they lived like animals’† (30). The author describes where people live as a sort of divider among them, the Ewells not only live near the blacks, but also right next to the garbage dump. Not only was the location of on...

Allotropes of Carbon Essay

Allotropes are the existence of an element in more than one form. Carbon is one of the elements that contain many allotropes. Each allotrope of carbon has its own different properties. The allotropes of carbon are diamond, graphite, fullerenes, carbon nanotubes, carbon nanobuds, amorphous carbon, glassy carbon, lonsdaleite, and carbon nanofoam. Diamond is the best know allotrope of carbon. It is the hardest known natural mineral which makes it very rough. In the structure of the diamond, each carbon atom is covalently bonded to four other carbon atoms and has a tetrahedral shape, meaning it is a nonpolar molecule. Diamond has a very melting point and has a density of 3.51 grams per cubic centimeter. Graphite is the second allotrope of carbon. Its atoms of carbon are arranged in layers. Within each layer of carbon atoms, the atoms join to form six-membered rings and each carbon atom is connected to three others. Two of the three bonds is a single covalent bond and the other bond is a double covalent bond. Graphite is very soft and slippery because the layers are not chemically bonded and can slide over the other. Graphite also has electrical conductivity and is less dense than Carbon since its density is 2.22 grams per cubic centimeter. A third allotrope of carbon is the fullerenes. Each atom is bonded to three other atoms of carbon just like in the graphite structure, however, the atoms join to form both five-membered rings and six-membered rings. The chemical properties of fullerenes are still being researched by scientists and they are also studied for potential medical use in the belief that they can be put into specific antibiotics to target bacteria and cancer cells. Another allotrope of carbon is carbon nanotubes. They have a cylindrical or circular cylinder shape. The name nanotube comes from their size because they only have a diameter of a few nanometers. They are made up of layers of graphite in the form of a cylinder and they are often closed at both ends(wikipedia). They exist as single or multi walled nanotubes. Carbon nanotubes have many properties that make them useful in many things. They are extremely strong, and they have special electrical properties. Their  unique electrical properties make them a very good conductor of heat. Nanotubes can be made in two ways. One is by mixing the soot of nanotubes of carbon in water and surfactant. The solution is rotated into a substance that is able to collect the nanotubes. Then a liquid is injected to help the formation of the rectangular shape, which later rolls itself into a cylinder shape. The other way is to decompose methane with a catalyst. Carbon nanobuds are a newly discovered allotrope of carbon. They have fullerene like buds that are covalently attached to the outer walls of nanotubes. It is basically a combination of carbon nanotubes and fullerenes. This is because nanobuds have a combination of the useful properties of both nanotubes and fullerenes. Carbon nanobuds are exceptionally good field emitters. Amorphous carbon is the name used for carbon when it does not have any crystalline structure. Some short range order can be seen but there is no long range pattern of atomic position. Amorphous carbon is used to describe the carbon materials found in soot and coal that is neither graphite nor diamond. Another allotrope of carbon is glassy carbon. Glassy carbon is a class of non-graphitizing carbon that is mostly used as an electrode material used in electrochemistry. It was first made by using cellulose but later it started being produced with a similar material phenolic resin. The making of glassy carbon is by taking organic precursors and exposing it to a series of heat treatments. Glassy carbon is impermeable to gases. The oxidation of certain glassy carbons in oxygen, carbon dioxide and water vapor are much lower then of any other carbon. They are also highly resistant to acids. Lonsdaleite is a hexagonal allotrope of the carbon allotrope diamond. This allotrope is also known as â€Å"hexagonal diamond†. It is believed to be formed when meteoric graphite falls to the Earth. The great heat and stress of the impact causes it to turn into diamond however it retains the graphite hexagonal crystal lattice. Lonsdaleite has a transparent brownish yellow color. It has a hardness of 7-8 on Mohs hardness scale. The reason why it  has a lower hardness then diamond is because of the imperfections in the naturally occurring materials. Lonsdaleite can also be made by the thermal decomposition of a polymer at the atmospheric pressure under argon starting at 110 degrees Celsius. A final allotrope of carbon is carbon nanofoam. It consists of a low density cluster assembly of carbon atoms strung together to form a three dimensional web. Each cluster of carbons are about 6 nanometers wide and have about 4000 carbon atoms that are linked together in graphite like sheets that are given negative curvatures. This is because there are heptagons within the regular hexagonal pattern(saskschools). Carbon nanofoam is a poor conductor of electricity and they have many unpaired electrons. It is believed that the unpaired electrons are due to bonding defects. http://www.chemsoc.org/ExemplarChem/entries/2003/bristol_shanley/carbonallotropes/ http://www.saskschools.ca/curr_content/chem20/networks/allotrop.html http://en.wikipedia.org/wiki/Allotropes_of_carbon

Language development Essay Example

Language development Essay Example Language development Essay Language development Essay The language during the observation showed that he was able to communicate confidently with the adult, he looked relaxed and he wasnt shy to talk. G was able to listen to the adult and answer the questions which were asked although sometimes he didnt understand the questions, for instance when the adult asked about colours, Gs answer was given as sun, Lindon (1993) says children get confused if given complicated instructions even though the question is not difficult for an adult it might be for a child. This might have been the case with G as the answer was different to the question or it could have been that he did not no the colour so he compared it  something he had seen of that colour e.g. a sun. Beaver et al (2001) say that a child of 3 and 6 months is able to use complete sentences. G showed he could do this, however his sentences were simple and not complex. G tended to use one word answers a lot of the time and as G spoke his word order was incorrect for example when he said ~we t~nd some more suns whats there, as stated in Beaver et al (2001) Word order is sometimes incorrect. G also demonstrated that he uses silly talk such as Yep and Yer instead of yes. Bruce et al (2000) states that Children love to use silly talk, Although G can say yes as shown in my observation, he chose not to. When G was talking about the sun shape he said goes in sky he missed the word the out which, as Sunderland says children carry on conversation but missing link words like the out. Lindon (1993) says Children will make mistakes in their pronunciation of words and in how they put sentences together G made a few mistakes but each time the adult still understood what was being said but didnt correct his speech. G was able to describe an object like something else (a simile) for example when he said its like sun as Beaver et al (2001) tell us he is linking ideas to speech. (i was able to discuss his environment because he noticed the picture of dolphins and started talking about them; Hobart and Frankel (1995) state that a 3 year old can relate to present and past experiences. G did show this as he was able to tell the adult about the dolphins. Beaver et al (2001) say that when G told the adult that he saw stars outside, he was using language to report on experiences. Sunderland states Children love telling adults what to do, G showed this as he kept asking the adult to look for shapes.  Conclusion  [feel that I have met my aim which was to observe and look at the language skills of a child. I observed G for about 30 minutes whilst he was standing at a table with bootlaces and different shaped beads he was also talking to an adult. I placed a tape recorder near G and the adult so that I could accurately record exactly what was said. I also watched them and recorded Gs actions whilst he was talking. I dont think that I would have changed the way I observed him as I wouldnt have been able to accurately write down everything which was said and how it was said. The tape was a good method because I could listen and rewind and listen again as many times as I wanted. It helped writing down his actions as well so I knew exactly what was going on whilst I listened to the tape at a later date. If I was to observe language again I would still use the same method as I think it was the best and most accurate.  G was at his normal stages for his age as Beaver et al (2001) say ~a child of 3 and 6 months can use complete sentences G showed this whilst he was talking to the adult, for example when he said a special thing for music. Although El has reached his developmental norms in language, some children reach them at different times and might be a little behind or a little in front. Personal learning I learnt that children do use silly talk but they can speak properly when needed and that children can get confused and need a little help to understand things. I also learn that children love telling adults what to do. I learnt that there are different types of questions, open ended and closed questions. The open ended questions need more than a one word answer and children would benefit from being asked these as they help with a childs language and pronunciation development. Recommendation I would recommend that when an adult is talking to G the adult should try and use open ended questions as El would probably benefit from this, as he would be able to build on his language skills and talk to the adult more, the adult asked closed questions such as Do you like dolphins? or What colour is that? These questions only need a short answer but if G was given open ended questions like What are you doing? or Why do you like dolphins he would be encouraged to answer with more than one word, which would help him to extend his language skills and pronunciations of words. I would help him by getting some picture cards and holding them up then get him to say what is on the card (e.g. an aeroplane) I would also ask him questions about the picture on the card. It would help improve his language skills. Also if G had his word order wrong, the person who was with him should correct him so he would know how words are said properly.

Student Essay

Student Essay Student Essay Student Essay: Useful Tips They say that student essay is just an awful task, which is hated by all the students, especially, student essay about education, as this is the task each student has to come through. Well, maybe this saying is right in some way, however, nowadays with the appearance of the Internet and different custom essay writing services student essay is not an executioner any more. If you have an access to the Internet you have an access to all the kinds of student essay writing tips, and student essay about education is not a problem as well. Here are several tips for you at the subject how to write student essay written by the professionals of our custom writing service who have completed hundreds of different student essays and won the highest grades to their customers. While you are writing your student essay, you have to remember one of the main principles of the successful student essay writing: do not tell what you want to tell, show it. Use the words in order to draw the pictures and to show the reader the text you are writing. Keep your reader hooked, instead of making him or her bored with your monotonous presenting the sequence of circumstances. Make a whole story from your student essay ( Choose the topic you are interested in and have a passion for. It is possible to write good student essay only on the topic, which is really interesting to the writer. If you like the subject, you are writing about in your student essay that means that you know a lot about it, that is why it will not take much time from you to search the necessary information. Do not write either too short or too long sentences in your student essay. You see if the sentences are too short all your student essay seems to be chopped and cut short. If you write too long sentences, your essay may seem to be too complicated and confusing. Write the sentences of average length, in order to show that you are able to express your ideas in a logical and clear way. Proofread the student essay after you think that it is completed. Different grammar mistakes, or wrong usage of words, or incorrect sentence structure, all this badly influence upon your grade for the student essay and show your indifference to the reputation and grade you are going to get. Read also: Term Paper on Personal Success Creative Writing Thesis Writers of Term Papers Dissertation Writers Dissertation Service

Financial ratio analysis Assignment Example | Topics and Well Written Essays - 750 words

Financial ratio analysis - Assignment Example However, the intention of the ratio computation in this case is for the investment viability and this implies that the relevant explanation of the ratios will be offered. We consider the current ratio, which helps in determining the financial position or ability of an organization to meet its short term obligation. The following formula is used to compute the current ratio A current ratio of 2:1 is considered to be most adequate for numerous organizations in testing the liquidity ratio. In this case, the two organizations are considered to be relatively able to meet their short term obligations. The profit margins indicates that the DOHA Bank is more profitable compared to the Commercial Banks of Qatar. In 2013, the DOHA Bank recorded 0.54 while the CBQ recorded 0.467. On the other hand, in 2012, the DOHA Bank recorded 0.85 while CBQ recorded 0.674 (Chesnick & United States, 2000). This is clear that the DOHA Bank is more viable for investment compared to the Commercial Banks of Qatar. From the debit ratio figures, the two companies seem to be spending nearly the same amount of debts to finance their organizations’ growth and development. This has an impact of creating volatile earnings (Chesnick & United States, 2000). However, DOHA Bank appears to be spending a little bit more in its operations and this explains that, it is able to generate more earnings, which are spread to the shareholders in terms of dividends. These ratios help the business to know whether it is meeting its goals of generating profits and satisfying the clients. In this case the total assets turn over will be computed using the following formula. These ratios indicate that the market viability of the two organizations is sound and they can thrive well, since their book value is almost the same as the market values of the shares (Chesnick & United States, 2000). From the above ratio analysis, it can be concluded that the DOHA Banks has more

Global health Essay Example | Topics and Well Written Essays - 2000 words

Global health - Essay Example The support and initiative from every country is beneficial as it evaluates the crises of health care and then takes a precautionary measure for diseases to stop them from spreading globally (Global Health Initiative, 2011). In this context, this paper intends to identify the role of philanthropy work such as the role played by Bill Gates through his benevolent activities in health related initiatives. The paper also intends to identify role of such initiatives in the context of existing WHO policy priorities. The challenge for global health is to study the real life cases and try to produce an innovative idea for the solution of the problems for health. The students or leaders or corporate or an individual can participate to overcome challenges against global health (UBN Global Health challenge, 2011). The Global Health Council is a non profit making organization and its mission is to develop better health globally by assisting, the one who works for improvement and progress of global health. The council secures the information required to work effectively. The Global Health Council is the globe’s largest membership association which consists of corporation, NGO’s, academic institution, foundation and government agencies that coordinates for the improvement of the global health (Global Health Council, n.d.). WHO (World Health Organization) is an institution which takes initiatives for the protection of health of the global populace. It is operating since 1948 and there are more than 190 countries as the members of WHO (World Health Organization). Every country has joined WHO to fight against certain threats related to health which may be harmful for other nations as well (World Health Organization in Belarus, n.d.). Philanthropy is the ethical event in response to ‘human problems’. It is essential for free civil society. Philanthropy is love for