Was World War One Responsible for Nicholas Ii’s Downfall Free Essays

Emily Hawkins How far do you agree that Nicholas II’s downfall was caused by World War 1? 1914 was a devastating year for many countries of the world, as world war one began to take full effect. But as world war one shook the world; it began to question Nicholas II’s ability to rule Russia. In this essay i will discuss the extent of world war one’s responsibility in Nicholas II’s downfall, and the extent of other contributing factors. We will write a custom essay sample on Was World War One Responsible for Nicholas Ii’s Downfall? or any similar topic only for you Order Now I will argue that Nicholas II’s own traits as a leader were the main reason for his downfall. On the one hand, world war one had a huge impact on the Tsar and his country. Firstly, the cost of the war was placing a huge strain on Russia’s economy. Taxes increased hugely and the cost of living rose by 300%, so in order to try and help the economy through the struggling times of world war one, the government printed more money, making all money worthless. The people of Russia were now struggling even more than they were before the war had begun. Secondly, the Germans were forcing the Russians to retreat and they were therefore losing a lot of land. The impact of the battle of Tannenburg, where 30,000 troops were killed and 95,000 captured had a huge impact on the army’s moral, and by the end of 1916, 2 million soldiers had left the army. The commander in chief shot himself because of how bad the country and the army were doing, and soon after, the Tsar himself took on the role of commander in chief, although he lacked ability and knowledge. Also, the military had a lack of resources, in each regiment in the army; there was one gun per three people; the Tsar was blamed for many of the military downfalls, and this was one of them. The Russian transport system was also facing serious problems, and the ammunitions being made in the factories weren’t getting to the front line. Thirdly, world war one was causing huge food shortages; in Moscow in 1914, Russia was receiving 2200 wagons of grain and by Christmas 1916, the number of carts was down to just 300. This was because of distribution problems; nobody could sort the carts out properly. They were prioritized to the front line, so that the soldiers got the first carts. But after the front line had been sent their grain, there was nobody sorting out the rest of it; there were carts found with bread rotting away, bread that the starving Russian people were missing out on. Although world war one was not the sole reason for Nicholas’ downfall, it did act as a catalyst. It increased the severity of the existing problems that Russia was facing. It also highlighted that the Tsar and the Romanov dynasty was no longer capable of ruling the country and that they didn’t have the support and determination to rule the country through a world war. On the other hand, there were many other reasons that the Tsar’s downfall occurred. Firstly, the strikes and demonstrations in Moscow and Petrograd were causing huge disruption, and when the Tsar tried to return to Petrograd, his train was stopped and he realised that he couldn’t control the protestors; a major sign that he had no control of Russia and its people. Secondly, the revolutionary parties were spreading their radical ideas around the country, and also highlighting the weaknesses of the Romanov dynasty. The Tsar’s downfall was prone because of the amount of opposition that he faced and his loss of support to the other political parties. Parties such as the Bolsheviks, Social Revolutionaries, Mensheviks and Populists educated the peasants and working-class people on the need for a new type of leadership; this encouraged strikes and discontent. Many of the strikes were purely because of the appalling living and working conditions, and for a while, the people united together because of the war, but when the Russian people began to feel the true cost of the war, the protests began to re-occur and more support for the Tsar was lost. Thirdly, because of the troops refusing to shoot at protestors on 25th of February, the army felt no longer obliged to be loyal to the Tsar. As long as the Tsar was not supported by the army, he had no chance of successfully running Russia. The Duma also refused orders to dissolve, and 12 of its members formed a committee that planned to take over Russia; the called themselves ‘The Provisional Government’. The soviets also issued ‘Order number 1’ which demanded that all officers in the army be elected by their men, proving that the Tsar had lost all of his power. Therefore, there were many factors involved in the Tsar’s downfall, such as the political opposition, strikes and the disloyalty of the army and the Duma. Once people started to support the other political parties, they lost all loyalty for the ‘God appointed’ Tsar. The strikes highlighted the weaknesses of the Tsar’s leadership skills and proved that he couldn’t no longer control and rule Russia. The disloyalty of the army and the Duma completely removed all of his power, meaning that Nicholas could no longer be Tsar. I personally believe that Nicholas II was responsible for his own downfall. Although there was definitely contributing factors, his naive attitude and inability to effectively rule a country caused his downfall. Nicholas failed to trust key advisors such as Witte and Stolypin and despite him issuing the October Manifesto; he preserved his own autocratic power through the fundamental laws, which the Russian people didn’t like. He failed to think and plan ahead to create a better future for Russia, he didn’t think like a leader should. Even though the war was already a huge strain on Russia, and on Nicholas, he still felt it necessary to take over the role of commander in chief of the army; although he had no experience or knowledge of the role. He was blamed for many of the army’s failure, and people stopped believing in him. By Christmas 1916, the Russian army were struggling and with Nicholas II as an unqualified leader, poor communications and shortages of food and supplies led to problems and Nicholas was blamed for the 1. million soldiers who died, the 3. 9 million wounded and the 2. 4 million who were now prisoners. As Nicholas was busy trying to incapably run the army, he left his wife in charge of Russia, his wife that nobody liked. As she was German born, the Russian people thought that she was sympathetic to the enemy, and they deeply mistrusted her. The Russian people looked at their leadership and saw the ineffectiveness; they began to look for alternative leaders. Also, people disliked the Tsar, as he took key advice from Rasputin, who was disliked by the population for making many ministerial changes, and they thought that he was having an affair with the Tsarina. Some radical parties began to plot the death of Rasputin as the Russian people looked for alternatives to the Romanov dynasty. Therefore Nicholas was responsible for his own downfall. People began to dislike him after he failed to listen to his key advisors and improve Russia. This was made worse by his inability to share power with the Dumas or any other political opposition. Russian people also hated the fact that Nicholas had taken the role of commander in chief of the army. He was unable to run the country, let alone the army as well. He had almost run Russia into the ground, and then he left it in the hands of someone that none of the population liked or trusted, so that he could take up a role he knew nothing about; which he failed at miserably, letting the country and the army down. Therefore, i believe that Nicholas was responsible for his own downfall. There were many other things to blame though, such as world war one, the disloyalty of the army, and his political opposition. As soon as world war one started, the Russian people began to see that Nicholas was incapable of running Russia and they looked towards the opposition for a way out of the autocratic state they had suffered so long. Once the loyalty of the army was lost, Nicholas had no chance of getting Russia back to how it was 100’s of years before. He knew that his time of autocracy, and the time of the Romanov dynasty was up. How to cite Was World War One Responsible for Nicholas Ii’s Downfall?, Essay examples

Humor was used in the medieval time period to expr Essay Example For Students

Humor was used in the medieval time period to expr Essay ess ones ideas and thoughts. Geoffrey Chaucer also used humor in The Canterbury Tales in different instances. In The Nuns Priest Tale and The Millers Tale I will show you how he uses humor to describe characters, his use of language and the actual events that take place. In the Nuns Priest Tale there is a rooster named Chaunticleer. His name suggests a fine knight or nobleprince. The description of a rooster as a noble prince in courtly love romances is ridiculas and maybe this is what keeps us from taking him to seriously in this story. Nicholas, a clerk or scholar, from The Millers Tale also has a ironic name. His name suggests St. Nicholas from plays about a mysterious guest at the home of evil hosts. In the story, however, its the other way around. In Chaunticleers description Chaucer uses a contrasting humor. The rooster acts as a noble knight or prince when in reality he is only a barnyard animal. The description of the barnyard animals brings an undercut from the courtly love that occurs throughout the tale. The reminds you to think that Chaunticleer and Pertelote are only animals which brings about a hilarious effect. With Nicholas, a lowly clerk, portraying a higher class gentleman when in essence he just wants a sexual pursuit and the meani ng of his name uses an ironic humor to show he is an idiot. With John, the carpenter, Alison, his wife, and Absalom, the priest, in The Millers Tale they also put on airs of being an upper class citizen.. They also bring you back to the basic idea they are common people just putting on a show for each other. The humor in description is very plentiful and Chaucer uses it to interest you in the story. We will write a custom essay on Humor was used in the medieval time period to expr specifically for you for only $16.38 $13.9/page Order now Another way Chaucer uses humor in these tales is his choice of language. In The Millers Tale Chaucer uses the word pivetee for Gods secret affairs when John talks to Nicholas in his room. Men sholde nat knowe of Goddes privetee (Oxford, line 346). It appears again in reference not to God but to the affair of Nicholas and Alison. This is a very ironic and funny usage of the language since one is holy and the other is evil. Chaucer uses the language of courtly love and description to point out human desires and weakness. Weakness because the beloved lady has the power of life or death over the lovesick Chaunticleer and/or Nicholas. Chaunticleer would have listened to his dream more if his beloved Pertelote hadnt played down his dream. Nicholas wouldnt have been speared if Alison wouldnt have had teased Absalom at the window. One more way Chaucer uses humor is the actual events or situations themselves. John is easily doped by being naive which leads to his downfall. Nicholas being a scholar in astronomy tells john that he has seen the next Noahs flood and should tie tubs to the roof of the house to beat this. As well that John and Alison should not sleep together because they will be awaiting Gods grace. The joke here is we dont know is Nicholas realizes that God sent Noah the flood because man became corrupt and lecherous. The same sins are causing the phony flood even though the planthis time isnt Gods. Chanticleer is also easily doped by the fox. The fox asks Chaunticleer if he could sing as well as his father did Let see conne ye you fader countirefete? (Oxford, line 166). It is ironic that his downfall is his very pride and joy his voice. An instance where Nicholas tells Alison his plan will work because a clerk can fool a carpenter any day is funny because this class distinction is humorous in the circumstances since all the character are common people even though they are trying to be noble and courtly. The fox also believes that his plan will work and does, even though they are just plain animals in a barnyard, he believes he is superior in thought since he is sly and a sweet talker. But trewely the cuase of my cominge/Was only for the herkne how that

Green Buildings and Sustainability

Introduction With the increasing concern of human activities on global warming, there has been an incredible attention on looking for mechanisms of reducing its impacts on the environment. One of the proposed mechanisms of addressing this challenge is building houses that are environmental friendly called green buildings.Advertising We will write a custom essay sample on Green Buildings and Sustainability specifically for you for only $16.05 $11/page Learn More Technically, green buildings refer to â€Å"structures designed using processes that are environmentally responsible and resource-efficient throughout the building’s life-cycle: from sitting to design, construction, operation, maintenance, renovation, and demolition† (Kats et al. 12). To achieve this state, it is desirable that there exists close cooperation between architects, various engineers, design teams, and clients in all stages of execution of commercial real estates’ building projects. This paper scrutinizes the characteristics that need to be possessed by a building for it to qualify as green coupled with questioning the capacity of the green movements across the globe to prescribe the construction of purely green commercial real estates. Environmental Impacts One of the central concerns of putting up green buildings is to help mitigate the environmental impacts associated with conventional buildings. However, in the process of building any house, there is always some extent of the natural environment disorientations and interference. This implies that the greenest building is the one that has not been built at all. Additionally, a building occupies a space that was originally occupied by other natural systems. Therefore, even if the process of the building does not degrade the environment by interfering with the ground structure, space is consumed. This has the impact of making most buildings fail to comply with the requirement that they make use of a small space. Furthermore, green buildings need not to contribute to sprawling, which is the tendency of structures to spread in a manner that does not follow any fashion (Kats et al. 12).Advertising Looking for essay on environmental studies? Let's see if we can help you! Get your first paper with 15% OFF Learn More These three rules for any green building are significant since the overall goal of going green in the development of commercial real estate pegged on the idea that people must put in place strategies for ensuring that energy absorption or release to the environment is kept minimal. In fact, International Energy Agency estimates that above 40 percent of the total global energy consumption is due to the buildings (Pushkar, Becker, and Katz 98). Buildings are also responsible for the 24 percent of the global carbon dioxide emissions (Pushkar, Becker, and Katz 98). Therefore, it is possible to manage the impacts of global warming due to environmental d egradation by controlling further development of ways of building real estates and shifting towards focusing on going the green way in building and construction. The only worry is whether this technology is sustainable and readily embraceable by all nations across the globe. Efficiency of Materials Building a green commercial estate calls for no extraction of materials from the environment particularly the ones, which are not renewable. Some of the materials that blend well with the concern are renewable materials obtained from plants such as straws, bamboo, recyclable stones and metals, sheep wool, paper flakes made panels, clay, non-toxic material, cork, and compressed blocks made from soil amongst others. To comply with the concerns of green building technology, it is prescribed that all materials that require processing such as earth blocks be processed right on the site where they are to be used to ensure that no energy is utilized in the transportation of the finished products . The mechanism of processing is also to be selected such that no fossil fuels, any other forms of non-renewable source of energy, or any sources of energy that would go into destroying or destabilizing the environment or the natural flora and fauna are utilized. However, utilizing high efficiency materials seem to be a subtle mechanism of ensuring that materials for the building will never end. Therefore, it is crucial to note that some impacts are produced on the environment while using these materials. For instance, when soil is dug for making earth blocks purposed for building green commercial real estates, the environment is affected in one way or another since earth crust is disturbed.Advertising We will write a custom essay sample on Green Buildings and Sustainability specifically for you for only $16.05 $11/page Learn More This outcome is not desired for a purely green building. Arguably, this qualifies as one of the reasons why it is incredibly difficult to sustain construction of 100% green buildings. In some situations, it is necessary that off-site manufacturing be done. This strategy is indispensable when it is desired to â€Å"maximize benefits of off-site manufacture including minimizing waste, maximizing recycling, high quality elements, better OHS management, and less noise and dust† (Kats et al. 57). This requirement makes green technology for building real estate problematic in that structures cannot be wholly manufactured off-site. Some form of joining is necessary. Some of the joinery processes used often lead to releasing some foreign matters to the environment to which green movement is largely opposed. Apparently, it is impractical to construct a whole earth block building off-site and then take it to the desired final site. This argument does not imply that measures should not be deployed to ensure observance of efficiency of materials. Rather, the point is that green techniques should focus on real istic things that are achievable within the spheres of existing building technology. For instance, it is acceptable here that scholars have proved that buildings play central roles in hiking the rates of global warming. Consequently, one of the mechanisms of reducing these impacts would be deployment of realistic green global warming reduction strategies such as utilization of greener forms of energy such as solar and wind energy in lighting and heating. This argument leads to the next characteristic of green buildings: energy efficiency. Energy Efficiency Green real estate deserves to be energy sufficient, energy efficient, and self-sustaining. This means that green commercial real estates require a high capacity to reduce energy consumption rates in terms of operating the energy required to power equipment and heat. In this end, the green movement prescribes the usage of materials, which have a low embodied energy in the construction of green buildings. Such materials include wood . Therefore, since steel has a high embodied energy, it is not a preferred green building material. Unfortunately, green buildings require that the materials used be highly recyclable. Steel perhaps fits well in this category of materials.Advertising Looking for essay on environmental studies? Let's see if we can help you! Get your first paper with 15% OFF Learn More On the other hand, although wood may be replenished, the rate at which forests are disappearing is alarming to the extent that many countries have resorted to restrictions of felling of some species of trees, which are under threat of extinction. Therefore, based on the needs to use materials with low embodied energy, green technology’s applicability in the development of commercially viable real estate encounters some drawbacks. However, amid the position taken above, other concerns of green building are realizable. For instance, it is practical to build a house that has a low operating energy. For instance, houses without air leakages can be designed and constructed successfully. This result is accomplished through constructing double-walled houses with the space between the two walls being airtight. The design incredibly aids in reducing total energy loss from the interior of the house so that minimal heating is required especially during cold weather. In addition, high pe rformance windows coupled with ceilings, floors, and walls that have extra insulation are commercially viable to make. Other practical strategies include proper designing of houses to take full advantage of natural lighting so that the necessity of electrical lighting is minimized. Solar heating may also act as an additional means of electricity cost reduction. Arguably, even though on-site power generation encompasses one of the most expensive features to install in a building, biomass, solar, wind, and hydropower remain as some of the most practical and viable ways of mitigating the environmental effects of commercial real estates. Water Efficiency One of the biggest challenges of the commercial real estates is the emission of dirty water into the environment. As argued before, since the main concern of green building is to minimize environmental impacts of buildings, the question of water quality and efficiency of its usage in commercial estates comes out conspicuous under the gr een building technology in relation to the development of commercial real estates. In this extent, Pushkar, Becker, and Katz reckon, â€Å"reducing water consumption and protecting water quality are key objectives in sustainable buildings† (104). Nevertheless, it is also vital to note that green buildings emphasize that resources should not be utilized at a rate that supersedes their rate of replenishment. Unfortunately, the practical scenario in many commercial estates is that aquifer’s waters are used at a higher rate than it is actually possible to replenish. Therefore, reliability on aquifer water to feed commercial estates does not encompass a measure of going the green way of building. For this reason, it is desirable that green commercial estates, if at all they are practical and possible to realize, have their water supplies from on-site harvested, recycled, and purified water. One crucial drawback of these approaches is that some of the methods of water purifi cation such as desalination utilize a large amount of energy, which in many nations is currently obtained through nuclear power generation. In this sense, in terms of providing reliable sources of water, it sounds imperative to infer that it is somewhat impossible to develop a purely green commercial estate since production of energy to desalinate water would lead to disposal of remnants of the nuclear reactions (nuclear waste) into the environment. This is highly not supported by the ideals of green buildings. The question that is left unaddressed by the green movements is that- is it possible to generate large amounts of energy to purify water for supplying to commercial estates through renewable means of power generation? Pay Offs and Costs Many opponents of green buildings cite cost of building as one of the main disadvantages of developing green commercial estates. For instance, according to Pushkar, Becker, and Katz, â€Å"Photo-voltaic, new appliances, and modern technologie s tend to cost more money† (110). However, in the long turn, green buildings can help to save lots of money. For instance, Pushkar, Becker, and Katz approximate that $130 billion can be saved by different sectors in the US on bills of energy. They further argue, â€Å"Studies have shown that some green buildings have yielded $53 to $71 per square foot back on investment over a 20 year life period† (Pushkar, Becker, and Katz 112). To the commercial real estate’s developers, this implies larger returns on investments in the long-term basis. Additionally, green buildings attract higher occupancy rates, higher selling prices, and reduced rates of capitalizations. This suggests that investments in commercial estates that are green introduce lower risks of investments. Arguably, amid the challenges of realizing a purely green building, this benefit provides substantive grounds for sustainability and attractiveness of green buildings particularly in the commercial real estate’s sector. Conclusion In the attempt to resolve a myriad of challenges emanating from waste disposal and excessive release or absorption of energy from the environment, this paper has argued that many organizations across the globe are advocating for a change of the manner in which people do things such as building. The focus is towards building green buildings. Such buildings are designed to consume less energy in lighting and heating, less water, as well as emitting less green house gasses besides providing their occupants with an environment that is healthy. They support harvesting of rainwater. They are built using recyclable materials. Amid these benefits of green buildings in comparison with conventional buildings, the paper maintains that building purely green commercial estates is problematic. However, bearing in mind the long-term cost benefits and investment risks accruing from building â€Å"green† commercial real estates, such estates prove sustainabl e in the long-term. Works Cited Kats, Greg, Leon Alevantis, and Mills Adam. The Cost and Financial Benefits of Green Buildings. New Jersey, NJ: Princeton, 2003. Print. Pushkar, Susan, Richard Becker, and Arthur Katz. â€Å"Methodology for Design of Environmentally Optimal Buildings by Variable Grouping.† Building and Environment 40.3(2005): 97-112. Print. This essay on Green Buildings and Sustainability was written and submitted by user Raquel Wilder to help you with your own studies. You are free to use it for research and reference purposes in order to write your own paper; however, you must cite it accordingly. You can donate your paper here.

Eal School Systems and Policies for Meeting the Needs of Children with Eal and or Black and Minority Pupils Essays

Eal School Systems and Policies for Meeting the Needs of Children with Eal and or Black and Minority Pupils Essays Eal School Systems and Policies for Meeting the Needs of Children with Eal and or Black and Minority Pupils Essay Eal School Systems and Policies for Meeting the Needs of Children with Eal and or Black and Minority Pupils Essay Essay Topic: Middle School EAL TASK 1 (Q13) School systems and policies for meeting the needs of children with EAL and/or Black and Minority Ethnic pupils What are the needs in this school regarding EAL and ethnic minority achievement? Middle Row Primary School has a population of 39% pupils who are bilingual. A total number of 21 different languages are spoken throughout the school. According to the Race Equality Policy, 57% of the pupils have English as an additional language. The school has a majority of the ethnic minority as stated below: 17% Mixed White/Caribbean Moroccan – 15% Black Caribbean – 12% Somali – 11% White British – 11% What written policies are there about the school’s approach? The school has a general EMA policy which highlights the school aims in regards to the needs of EAL children. According to the policy the school employs a full time teacher funded by the Language Development Service other than 2 teachers which are funded by the school. In reali ty there is one full time EAL teacher. There is also a section in this policy on new arrivals to the school where it states that the school ‘ runs an induction programme for pupils at the very early stages of learning English. Furthermore, in terms of learning and teaching, the EMA policy acknowledges the large number of pupils which qualify for EAL support, therefore it prioritises its support offered. The EAL teacher liaises with the class teacher in terms of the child’s assessment and development. The school also has a Race Equality Policy to ensure the school/staff fulfils its obligation under the Race Relation Act 1976 [amended 2000]. What are your school’s procedures for raising the standards of BME children and/or children with EAL – are there any particular support programme, strategies or resources used? Middle Row uses the RBKC’s assessment forms for children with EAL needs. This is practiced twice a year by the school staff. Other than this, the EMA teacher and the class teacher also assess children each term. Target levels are than set for the child to achieve by the end of next term. The assessment includes speaking and listening, reading and writing skills test for literacy. What support is available for children at the whole school and classroom level for both groups? The EMA teacher not only works alongside with the Class teacher during sessions or can arrange one to one sessions depending on the class timetable. Due to shortage of staff it becomes impossible to extend support to each and every EAL child present in the school. Support is still provided to the best of ability. How are parents involved and what systems exist for developing home-school relationship? In autumn term (Nov ’09) MRPS in coordination with the RBKC arranged a session for the parents of EAL children. Many parents attended the session, which was mainly focused on the importance of home languages. The school is working towards involving the parents and having more sessions on developing home-school relationships. In the past there have been sessions on parent child reading in the classroom which was quite a success. Find out how it uses local and national data to inform its practice. Are there any particular groups that are targeted for support? The school prioritizes in providing support to beginner levels of EAL children. So far, the school haven’t categorised any particular target group as the main focus stays with children who are new in the country or the ones with little or no English language at all. In what ways have the children’s knowledge and experiences been taken into ccount in curriculum content? The Friday assemblies are a main feature which highlights different cultures and traditions. The children can relate to these assemblies as the parents of children performing are invited to watch the assembly. Awareness is spread about issues like racism and bullying. When planning sessions, teachers do tend to keep interest of the child’s knowledge and experiences and try and make a relation from the curriculum point of view. What place do first languages and culture have in the school and classroom? Does it promote pluralingualism? First languages are not spoken as commonly probably because English is the main language spoken. Spanish is a popular language in the school because of the presence of specialist Spanish staff. Lessons are delivered every week in Spanish and children tend to enjoy these sessions. The school does promote pluralingualism as the school staffs cherish children who speak other languages. Display posters, dual language books are available in the school but not put into much use as one would imagine.

Green Building and Sustainable construction Essay

Green Building and Sustainable construction - Essay Example Some of the methods used to address the environmental sustainability of a structure involve recycle and reuse of materials, ensuring the building uses renewable energy source or employs energy and water saving methods. Besides the accessibility of the building, can make be used to gauge whether the building is environmental friendly? Buildings, which are far away from transport network, can be considered less environmental friendly. Sustainable construction involves use of environmental friendly materials for construction. Use of wood from trees, which have been certified by the United States Forest Stewardship Council (FSC) is one way of promoting sustainable construction. FSC ensures the trees which are used for construction purpose are replaced and the existing biodiversity is not affected by cutting down of a particular tree. Sustainable construction also involves the use of renewable materials which can be recycled or reused. While promoting sustainable construction additional materials, which may not be renewable in nature, are used. The purpose of using such materials is to improve the overall performance of the building. A good example is use of plastic to insulate buildings; here plastic is used because of its availability and energy saving nature. Use of locally available materials is an economical way of saving on cost and reducing pollution of the environment. Transporting materials from another place would require use of means e.g. trains; heavy trucks which would definitely pollute the environment. When a building use available energy effectively, it is economically and environmentally sustainable. Measures to ensure such state is achieved included use of insulate which prevents loss of heat, use of glass windows on most part of the building to promote natural light penetration thus save on lighting and heating. Ensuring the lighting and appliances within the building are

Genentech's move to restrict the use of its drug Avastin, its Cancer Essay

Genentech's move to restrict the use of its drug Avastin, its Cancer Drug, by ophthalmologists on Eye - Essay Example in disallowing physicians and pharmacists from obtaining Avastin from wholesale distributors1, there are still questions pertaining to the motives which need clarification. Why do they have to restrict the distribution of Avastin for off-label use? Why did they have to refuse the proposal of the American Ophthalmologist Community to conduct a comparative study between Avastin and Lucentis in AMD? What are their motives in doing this decision? We cannot hastily justify, so we are not yet certain whether they are just protecting their own financial interests, or there might be other reasons behind this decision which necessitates such action. Even though the FDA approved the use of Avastin not for ophthalmic use, there is no issue of legality should physicians use the drug other than its recommended indication2, when the physician believe it to be appropriate, under his own risks of doing a medical malpractice3. Due to the drug’s anti-angiogenesis property, it was being used by physicians in treating various eye disorders precipitated by the leak caused by the blood vessels in the eye causing detachment of the retina4. The studies regarding the use of Avastin in eye disorders thru Pubmed search (limited to clinical trials and RCT and published within 3 years) reveals positive beneficial effects, yet requiring further long-term clinical studies. An attempt to investigate the long-term comparison between the two drugs was still on-going, yet an early result of the prospective randomized controlled trial reveals no difference between Avastin and Lucentis in effectiveness for choroidal neovascularizaton secondary to AMD5. Genentech’s decision to allow or suppress the availability of Avastin to the market may have legal implications that would threaten the company. The FDA approves the indication for the drugs after undergoing extensive research, toxicological assessments and clinical trials6. However, using the drugs beyond its indicated use, called

Vapor Compression Refrigeration Cycle Engineering Essay

Vapor Compression Refrigeration Cycle Engineering Essay A compressor is a mechanical device that used increases the pressure of a compressible fluid. The inlet pressure level can be any value from a deep vacuum to a high positive pressure. The discharge pressure can range from sub-atmospheric levels to high values in tens of thousands of pounds per square inch. The inlet and outlet pressure are related, corresponding with the type of compressor ant its configuration. Compressors are similar to pumps: both increase the pressure on a fluid and both can transport the fluid through a pipe. The fluid can be any compressible fluid, either gas or vapor, and can have a wide molecular weight range, that are from 2 for hydrogen to 352 for uranium hexafluoride. As gases are compressible, the compressor also reduces the volume of a gas. Liquids are relatively incompressible, so the main action of a pump is to pressurize and transport liquids. Applications of compressed gas vary from consumer products, such as the home refrigerator, to large complex p etrochemical plant installations. A vapor compression refrigeration system uses a refrigerant sealed in an airtight and leak proof mechanism. The refrigerant is circulated through the system and it undergoes a no of changes in its state while passing through various components of the system. Each such change in the state of vapor is called a process. The process of repetition of a similar order of operation is called a cycle. The compression cycle is given this name because it is the compression of the refrigerant by the compressor which permits transfer of heat energy. The refrigerant absorbs that from one place and releases it to another place. In other words the compressor is used to put the heat laden refrigerant vapor in such a condition that it may dispute the heat it absorbed at low pressure from the refrigerated space, to an easily available cooling medium. Oil refineries, petrochemical and chemical processing plants, and natural gas processing plants are among the many types of industrial plants that often u tilize large vapor-compression refrigeration systems. 2.1 Description of Vapor Compression System Most of the modern refrigerators work on this cycle. In its simplest form there are four fundamental operations require to complete one cycle. Compressor The low pressure vapor in dry state is drawn from the evaporator during the suction stroke of the compressor. During compression stroke the pressure and temperature increase until vapor temperature is greater than the temperature of condenser cooling medium. Condenser When the high pressure refrigerant vapor enters the condenser heat flows from condenser to cooling medium thus allowing the vaporized refrigerant to return to liquid state. Expansion Valve After condenser the liquid refrigerant is stored in the liquid receiver until needed. From the receiver it passes through an expansion valve where the pressure is reduced sufficiently to allow the vaporization of liquid a low temperature of about -10C. Evaporator The low pressure refrigerant vapor after expansion in the expansion valve enters the evaporator or refrigerated space where a considerable amount of heat is absorbed by it and refrigeration is furnished. The schematic diagram of the arrangement is as shown in Figure 2.1 below. The low temperature, low pressure vapor at state B is compressed by a compressor to high temperature and pressure vapor at state C. This vapor is condensed into high pressure vapor at state D in the condenser and then passes through the expansion valve. Here, the vapor is throttled down to a low pressure liquid and passed on to an evaporator, where it absorbs heat from the surroundings from the circulating fluid (being refrigerated) and vaporizes into low pressure vapor at state B. The cycle then repeats. B D C A Figure 2.1: Simple Vapor Compression System. The exchange of energy is as follows: Compressor requires work, w. The work is supplied to the system from the surroundings During condensation, heat Q1 the equivalent of latent heat of condensation etc, is lost from the refrigerator. During evaporation, heat Q2 equivalent to latent heat of vaporization is absorbed by the refrigerant. There is no exchange of heat during throttling process through the expansion valve as this process occurs at constant enthalpy. 2.2 Simple Vapor Compression Cycle Figure 2.2 below shows the simple vapor compression cycle: Figure 2.2: Simple Vapor Compression Cycle Process 1-2: The refrigerant as a mixture of liquid and vapour corresponding to state point 1 enters the compressor where isentropic compression takes place. The compression process increases the temperature of refrigerant from lower limit T2 to the upper limit Tl. Work is supplied to the system and after compression, the vapour is wet or saturated but not superheated. Process 2-3: The refrigerant in the form of vapour enters the condenser at state 2 and heat is rejected at constant pressure and temperature. At exit from the condenser, the refrigerant becomes saturated liquid at state point 3. Process 3-4: The refrigerant at state point 3 enters the expansion cylinder expands isentropic ally and its temperature drops to lower temperature T2 at the end of the expansion process. Work is obtained during the expansion process. Process 4-1: The liquid refrigerant at point 4 enters the evaporator and extracts heat at constant pressure and temperature from the space or substance being cooled and thus produces refrigerating effect. 2.3 Refrigeration Refrigeration may be defined as lowering the temperature of an enclosed space by removing heat from that space and transferring it elsewhere. A device that performs this function may also be called a heat pump. Freon is a trade name for a family of haloalkane refrigerants manufactured by DuPont and other companies. These refrigerants were commonly used due to their superior stability and safety properties: they were not flammable nor obviously toxic as were the fluids they replaced, such as sulfur dioxide. Newer refrigerants that have reduced ozone depletion effect include HCFCs (R-22, used in most homes today) and HFCs (R-134a, used in most cars) have replaced most CFC use. HCFCs in turn are being phased out under the Montreal Protocol and replaced by hydrofluorocarbons (HFCs), such as R-410A, which lack chlorine. However, CFCs, HCFCs, and HFCs all have large global warming potential. Newer refrigerants are currently the subject of research, such as supercritical carbon dioxide, known as R-744.[4] These have similar efficiencies compared to existing CFC and HFC based compounds, and have many orders of magnitude lower global warming potential. 3.0 TYPES OF COMPRESSORS 3.1 Centrifugal Compressor Centrifugal compressors use a rotating disk or impeller in a shaped housing to force the gas to the rim of the impeller, increasing the velocity of the gas. A diffuser (divergent duct) section converts the velocity energy to pressure energy. They are primarily used for continuous, stationary service in industries such as oil refineries, chemical and petrochemical plants and natural gas processing plants. Their application can be from 100ÂÂ  horsepower (75ÂÂ  kW) to thousands of horsepower. With multiple staging, they can achieve extremely high output pressures greater than 10,000ÂÂ  psi (69ÂÂ  MPa). Many large snowmaking operations (like ski resorts) use this type of compressor. They are also used in internal combustion engines as superchargers and turbochargers. Centrifugal compressors are used in small gas turbine engines or as the final compression stage of medium sized gas turbines. 3.2 Axial Flow Compressor Axial-flow compressors are dynamic rotating compressors that use arrays of fan-like airfoils to progressively compress the working fluid. They are used where there is a requirement for a high flow rate or a compact design. The arrays of airfoils are set in rows, usually as pairs: one rotating and one stationary. The rotating airfoils, also known as blades or rotors, accelerate the fluid. The stationary airfoils, also known as stators or vanes, decelerate and redirect the flow direction of the fluid, preparing it for the rotor blades of the next stage. Axial compressors are almost always multi-staged, with the cross-sectional area of the gas passage diminishing along the compressor to maintain an optimum axial Mach number. Beyond about 5 stages or a 4:1 design pressure ratio, variable geometry is normally used to improve operation.Axial compressors can have high efficiencies; around 90% polytropic at their design conditions. However, they are relatively expensive, requiring a large number of components, tight tolerances and high quality materials. Axial-flow compressors can be found in medium to large gas turbine engines, in natural gas pumping stations, and within certain chemical plants. 4.0 APPLICATION OF COMPRESSORS Gas compressors are used in various applications where either higher pressures or lower volumes of gas are needed: Pipeline transport of purified natural gas To move the gas from the production site to the consumer, or the transportation of goods through a pipe. Most commonly, liquid and gases are sent, but pneumatic tubes that transport solid capsules using compressed air have also been used. Often, the compressor in this application is driven by a gas turbine which is fueled by gas bled from the pipeline. Thus, no external power source is necessary. Plants and refineries Petroleum refineries, natural gas processing plants, petrochemical and chemical plants, and similar large industrial plants for compressing intermediate and end product gases. Refrigeration and air conditioner equipment To move heat from one place to another in refrigerant cycles: see Vapor-compression refrigeration. Gas turbine systems To compress the intake combustion air Commercial industry Storing purified or manufactured gases in a small volume, high pressure cylinders for medical, welding and other uses. Cylinder SCUBA diving, hyperbaric oxygen therapy and other life support devices to store breathing gas in a small volume such as in diving cylinders. Many various industrial, manufacturing and building processes to power all types of pneumatic tools.