American Muslims in the United States Research Paper

American Muslims in the United States - Research Paper Example This means the rest of the population could be Muslims on temporary visits and residence in the country. In as much as this diversity has an aesthete, a deeper scrutiny reveals It is essential to highlight of the notable factors that have influenced movements of Muslims from the Middle East to the US. To begin with, Arabs, as Muslims, have pursued education in the Western countries. This thrives on the belief that the Western countries have better educational structures and systems than home countries. In addition, economic incentives such as job opportunities and a dynamic investment platform attracted the Arabs. Emigration could also be explained by the wars and instability in the Middle East. The core character of this migration has majorly contributed towards the misconception of Muslims. To begin with, a common stereotype describes Muslims as only Arabs (Sirin and Fine 198). This belief ignores the fact that the Muslim community is a culturally diverse population. For instance, there are South Asians, Arabs, and African Americans in the Muslim community. Indeed, around 60% of US born Muslims are African Americans (Bayor 19). In spite of the excessive illuminated attention towards the Arab Muslims, African American Muslims have existed since the days of civil rights movement. Malcolm X, an activist for African Americans’ right, is one of the most conspicuous of this outfit (Abdullah 11). In addition, these groups have diverse styles of worship that are unique to their unique ethnic identity. It is crucial to highlight that the stereotype and misconceptions about Muslims is largely a media and commercial-driven phenomenon. Americans mostly drive their preconceptions and misconceptions from the films and commercials that portray Muslims in give ways. To begin with, films and commercials significantly portray Arabs as Muslims and portray

Feminist Perspectives on Land Law Essay Example | Topics and Well Written Essays - 3000 words

Feminist Perspectives on Land Law - Essay Example One of the important social factors contributing to this question has resulted from the fact that in recent year's family home has been used to secure for business borrowings in which both spouses are required to sign the relevant documents. There have been other economic and political factors which has supported this economic decision. This presents a new situation which brought to surface the impact of 'undue influence' on the minority and weaker section representing wives; on the ground of emotional and financial dependence on the husband. Some of the other factors have been increased owner-occupation since second World war, government encouragement to small businesses in 1980's and increasing trend for spouses to hold jointly the legal title to the family home.. The real source of the problem has emerged from the fact that though wife is now required to execute documents charging the family home, it does not necessarily mean that she has an equal involvement with her husband in planning the transaction or an equal voice when it comes to making the decision to sign. The role of the courts in the English law, is significant, while they respond to an increasing rhetoric of equality in English society througho... And it can be seen that judges have been even more creative in the way they have managed to limit women's rights to a successful claim or defence, to limit women's claims even when they appear to 'win' their case, and to ensure that men generally do better out of these disputes than women. The equality and justice is hard to sustain on the facts. (Auchmuty,2005)1 The focus of this discussion is evaluation and examination of the unfair justice practiced with regard to the position of the women, when it comes to equal treatment, in the matters concerning property disputes. On many instances it can be seen in the context of English Law that men and commercial lenders and other individual have been the greater beneficiary in comparison to women. The law and the judges have invariably favoured the possession of property to male members and commercial lenders with bias against their social disposition to manage and maintain property. English women have not been treated equally in relation to property; they have consistently been denied their fair share in property ownership. The biggest test for the courts and the judges have been in the cases where there is legal rhetoric and legal reasoning, which have supported unfair shares between the two genders in attaining court resolutions of informal co-ownership disputes and unfair outcomes in undue influence cases involving mortgagees. The rules of equity need to protect women as in many cases even judges lean towards male bias. "Married women could and probably should benefit from special protection in property law; that is , because married women suffer special disadvantage on account of their structural

Economies Of Scale In Airlines Management Essay

Economies Of Scale In Airlines Management Essay Abstract The following report is aimed at examining the economies of scale concept and strategies in the airline industry. This document is divided into several pieces which discuss the impact of the economies of scale on the main aspects of the airline industry. The last section of the document concludes. Introduction The financial aim of firms is to increase the shareholders capital (Atril, P., Mc Laney E., 2008). Business management, then, have to either optimize asset utilization or reduce firms costs. Current economic situation have managed industries to achieve historic levels of asset optimization. Therefore, special emphasis had been put in cost reduction strategies during the last decade (Akan, M., Ata, B., Lariviere, M. A., 2011). Airline companies were one of the industries which suffered, almost immediately, the effect of these new market conditions. To cope with this scenario, the industry implemented several cost saving strategies; among them the economies of scale'(EoS). The following document is aimed at examining the term EoS and analysing how applicable the concept is to major carriers/airlines. The document is divided into eight pieces. The first discusses how the EoS applies to the airline industry. The remained sections comment on how the EoS affects: the airlines purchasing process, managerial procedures, marketing, technology usage, consolidation, and the open skies strategy. The last section concludes. Economies of scale in airlines EoS can be defined as any cost reductions, responding to increased demand for output, moving along a given, downward-sloping long run cost curve (Grieve, R. H., 2010). In other words, the demand allows firms, in this case airlines, to distribute costs over a greater number of products/services. Airlines have put in place several strategies to increase the number of flights. Among them: ticket-selling process optimization, in-flight meal reduction/suppression, alliances, and consolidations (Harvey, G., 2009). EoS concept assumes that increasing returns emerge at the level of the firm. However, some authors claim that EoS does contribute to cost reductions, but turnover growth does not generally manifest itself in this manner. Empirical evidence has shown that EoS only helped those airlines which do not lose their identity when demand increases. That is, Airlines which do not lose the control of the service delivery even they rely in a complex provider structure. Following this train of thought, EoS are of little importance in accounting for increasing returns, since these return rates are attributable to other factors such as external economies or industrial differentiation (Grieve, R. H., 2010). A successful example of EoS implementation is Star Alliance. Star Alliance is a network of 24 member airlines. Lufthansa and United airlines have registered an important growth in its passenger airline group during 2010 (DATAMONITOR, 2010). Whereas, a failed implementation, MexicanaClick, a low cost airline which was property of the second largest Mexican carrier (Mexicana), did not produced the expected results (BBC, 2010). The EoS effects in purchasing processes The implementation of EoS has forced airlines to change their business model. Traditionally, ticket selling was made in two main forms: over the airline counter or via an agent. Information Technologies (IT) have modified this process. Customer can directly make reservations and buy tickets without by themselves. Therefore, ticket agents have evolved to electronic system which provided the function of searching, reserving, and selling tickets making the purchasing process more accurate, fast, and reliable (Singh, A.Kr., Das, D., 2010). In the same manner, EoS has managed airlines to establish stronger relationships with their suppliers. For instance, the supply IT systems have allow airlines to avoid intermediaries in the requisition of resources since mid 80s, therefore, their logistic costs have decreased (Caves, D. W., et al, 1984). Investments in these matters have allowed Lufthansa to be the third largest airlines of Europe, and the worlds fifth largest airline in terms of overall passengers (Singh, A.Kr., Das, D., 2010). EoS and managerial procedures Outsourcing is the most recurrent strategy of the EoS. By outsourcing activities, the airline allows market forces to reduce the costs of subcontractors who offer for the business (Harvey, G., 2009). However, some author claim that high specialization, in providers, jeopardize business continuity of the outsourced firm (Grieve, R. H., 2010). Nowadays, airline employees are based in different parts of the world, sometimes in places where salaries and benefits are lower than their airline-home based colleagues. In this manner, airlines have also relocated business functions to take advantage of lower wages and social charges incurred in some countries. For instance, British Airways relocated its ticket processing function to New Delhi (Harvey, G., 2009). EoS and marketing Marketing function has also been affected by EoS. Alliances have switched this function to major airlines. Major airlines are responsible for the marketing trips for routes which are composed of international and local courses. In this manner, major companies deliver the international legs of the trip and regional airlines the local ones. When the complete journey is made by two major companies, the role of major and regional firms are switched. That is, the airline which delivers the international leg is responsible for the marketing duties of that trip and vice versa. Additionally, these functions are, most of the times, outsourced. The flight Atlanta-Barcelona is a good example. British Airways is responsible for the marketing of that route, but it only delivers the track from Atlanta to London. The second leg, London-Barcelona is delivered by Iberia; whereas in the route Barcelona-Atlanta, these functions are switched (Wright, C. P., et al, 2010). In the case of regional or small companies, marketing function is totally absorbed by the major company, since regional/small firms do not have the required infrastructure to perform this task (Forbes, S. J., Lederman, M., 2010). Technology in airlines IT systems are the most popular EoS strategy. They have not only changed the airlines purchasing process, but also have optimized the occupation and improved the communication with providers (Pilarski, A., 2005). However, that is not enough. Energy represents one of the biggest costs of the airlines. Air France-KLM and Air China reported that fuel costs accounted for almost 39% of its global costs in the fiscal year 2009 (DATAMONITOR, 2010). Thus, better engine technology, logistic, and route planning system will help the airlines to reduce these costs. Airlines have not been able to apply EoS to aircraft technology since they have a higher dependency in two main providers: Airbus and Boeing (DATAMONITOR, 2010). Generally speaking, the whole industry efficiency depends upon technological advances and cost improvement that these two companies may achieve. Therefore, it can be said that all technology which does not directly depend upon airlines is already optimized. Air France-KLM and Delta are a good example of technological optimization since some of their process like luggage registering and check-in can be done by the customer himself avoiding long queues. Consolidation of the airline industry Consolidation is also a well known EoS strategy. Consolidation is mainly aimed at reducing costs by combining mature and efficient processes into one unique entity (Oum, T. H., et al, 1995). Some authors claim that consolidations make airlines to increase their market share. However, Empirical evidence has shown that market share remains stable. For instance, in the 70s five US airlines controlled 87% of the global market. In 2003, none of these five airlines exist, although the share of the top-10 airlines in all traffic was 86% (Pilarski, A., 2005). On the other hand, consolidations are long and complex processes due to tax and aeronautical regulations. Alliances have been a optional strategy for consolidations. Alliances is formed by any two airlines that exchange interline passengers and that have a proration agreement for the revenue collected from the sale of interline itineraries. In this manner, an airline can expand its destinations and, therefore, increase its revenues. In 2006, 59% of all worldwide available seat miles were flown by airlines belonging to one of the three largest international alliances: Star, SkyTeam, or oneworld. Alliance activity is expected to continue growing (Wright, et al, 2010). Therefore, alliances seem to be the right strategy for the industry. Open skies strategy The open skies strategy consists on allowing airlines to fly within one country, that is, no restriction in local services. In this fashion, an airline may design routes to cover local routes and directly compete with regional firms. The agreement between US and the EU allows airlines to reduce costs of share codes and to improve their costing schema. European airlines which are already consolidated with American ones can operate as one entity, because they do not have restrictions to operate in both regions and vice versa. However, European Court of Justice has found that this agreement is breaking the law, thus, some amendments have to be done to this agreement (Yu-Chun, C., et al, 2009). Open skies strategy is not a direct result of the EoS, but a mean to achieve it. This strategy was created to impulse airline industry in the 1940s. Thus, agreements like that in other regions will allow airlines to reduce their costing schema and to increase their market participation. Conclusions Airline industry is the foundation stone of the current global commerce. Its high efficiency has allowed firms to sell their products in other regions with competitive prices. On the other hand, this industry is a facilitator for some others. Its relevance has been exposed during natural disasters when airports are blocked and products cannot be transported. Current economy cannot be understood without air transportation. The challenge of airlines, now, is to find creative ways to continue their optimization and profitable continuity. Airline industry allows us not only to reach any part of the world, but also to have a competitive and trustable economic system.

Irony in the Story The Lottery by Shirley Jackson Essay -- The Lottery

Irony in the Story The Lottery by Shirley Jackson   Ã‚  Ã‚  Ã‚  Ã‚  In Shirley Jackson’s â€Å"The Lottery† irony is an underlying theme used throughout the story. The setting is introduced as a â€Å"clear and sunny† day, but ends with the brutal death of a housewife (715). The two people who essentially run the town, Mr. Graves and Mr. Summers, also have ironic names. In addition, the characters and the narrator make ironic statements throughout the story.   Ã‚  Ã‚  Ã‚  Ã‚  The plot as a whole in â€Å"The Lottery† is filled with ironic twists. The whole idea of a lottery is to win something, and the reader is led to believe that the winner will receive some prize, when in actuality they will be stoned to death by the rest of the villagers. The villagers act very nonchalant upon arriving at the lottery; which makes it seem as if it is just another uneventful day in a small town. Considering the seriousness of the consequences of the lottery, the villagers do not make a big deal about it. Under the same note it is ironic that many of the original traditions of the lottery, such as the recital and the salute, had long been forgotten. All that the villagers seemed to remember was the ruthless killing of a random person. It also seems strange that they let the equipment for the lottery, the black box, get into such a poor condition.   Ã‚  Ã‚  Ã‚  Ã‚  The two people who run, and the lottery, Mr. Summers and Mr. Graves. Mr. Graves is the postmaster for the town and is the person who swears Mr. Summers in as the lottery officia...

Green Roof

Many people don’t know what green roof is. So, what it is? A green roof is not a surface painted green, it is a living surface of plants growing in a soil layer on top of the roof. A thinner or thicker soil layer is spread over the roof membrane itself, sometimes with a protective root barrier, often with a drainage layer underneath. On the substrate, draught-tolerant species of plants are grown. Roof vegetation like this one doesn’t at all damage the waterproofing membrane of the roof. In fact it protects it from the uv-light which does damage the membrane over time.There are two types of green roofs: extensive and intensive. There are some differences of its. An extensive roof has very thin soil layers, draught tolerant plants and requires little or almost no maintenance. The limitation here is in the choice of plants. Extensive roof can be established on a very thin layer of soil. An intensive roof garden has much thicker soil layers, and can look like an ordinary ga rden, with trees and shrubs. Intensive roofs are more park-like with easy access and may include anything from kitchen herbs to shrubs and small trees.This of course needs as much maintenance as a garden does, and can only be constructed on a roof that can bear heavy loads. (http://en. wikipedia. org/wiki/Green_roof) It doesn’t matter what type roof is, but construction is a similar. Construction includes drainage materials, plant materials and establishment methods. For each green roof project, different site conditions and your aims and motives will govern the choice of materials and establishment methods. Therefore, if you are planning to build a green roof, consider the following two sections carefully.There are some roof sections which are important. First is a waterproofing. The membrane is made waterproof, and it will stay waterproof unless it gets physically damaged or aged. What ages a bitumen membrane is mainly uv-light and temperature extremes. Unless the roof memb rane is damaged while laying the green roof, the soil and vegetation cover protects the membrane from these types of injuries later. (http://www. greenroof. se/? pid=32&sub=19) Second section is root barrier. The asphalt waterproofing itself is not classified as root resistant and had to be reinforced with a root barrier.This barrier consists of rubberized asphalt enforced with polyester and treated eight a root-repelling agent. There are also synthetic waterproofing membranes (like PVC liners) available that are root resistant and do not require an additional root barrier. Different countries have different building practices and rules for green roofs – and many countries have no rules at all yet. In Germany, for example, a root barrier is always laid under a green roof. This is to ensure that no roots can damage the waterproofing.A root barrier is sometimes incorporated in the drainage layer. It can be chemical and poisonous to plants, or it can be a thin copper sheet, or r ubber sealed so as to avoid seams. If your motive for having a green roof is sustainability and ecological consciousness, it’s a good idea to ask your contractor about the method. In Sweden, the usual practice is that under extensive roof vegetation (2 – 5 cm soil), where only sedums and moss can survive, an extra root barrier is not considered necessary, since the sedums used have weak roots, and moss has no roots at all.When the soil layer is thicker, and therefore can hold more water, other plants grow there, and there is a risk of getting weeds with more penetrative roots. Second layer is insulation. Insulation boards can be made from extruded polystyrene which has high water resistance and compressive strength. The main difference from the old roof is that the insulation layer must be places above the waterproofing membrane, but on the new roofs insulation must be located below the waterproofing. Second, but not less important, is drainage.The main reason for usin g a drainage layer is that if a lot of water drains off along the surface of the soil, this will cause erosion. The second reason, is that for roofs which are almost flat, too much water would remain on the roof, forming puddles. Especially sedum vegetation is adapted to dry conditions, and tends to rot if submerged. Besides, too much water available can lead to unwanted plants establishing on the roof. Another function of the drainage materials that are often used is to store some amount of water.This effect becomes more and more important the drier the conditions on the roof are, due to climate, a steeper slope or other conditions on the roof. Drainage materials used in green roofs include natural materials, recycled materials and manufactured drainage mats. (â€Å"Green roof systems† Susan K. Weiler, Katrin Scolz-Barth) And finally, the top layer is growing medium with plants. The growing medium provides nutrients and structure for the roots to anchor in. the proprietary m ixes of the manufacturer consist of a lightweight aggregate, expanded shale, and some compost.The organic components make up about three to six percent of the shallow planting areas. The mix for deeper planting areas has slightly more organics. This mix is also heavier and allows a higher water-holding capacity in order to support the larger plants of these areas. In conclusion, one has to realize that there is no cookie cutter approach when it comes to the design of a green roof section. Though certain layers are always present – waterproofing, root barrier, insulation, protection layer, drainage layer, growing medium – their actual composition varies widely responding to a particular situation. â€Å"Green roof – a case study† Christian Werthmann) Green roofs have many advantages. One is a cooling effect. It is very useful effect for individual houses at summer time. A black bitumen roof easily reaches temperatures of 80 ° Celsius in the summer. When a soil layer and the shading plants protect the roof, the surface temperature usually doesn’t rise above the surrounding air temperature. A study conducted by Environment Canada found a 26% reduction in summer cooling needs and a 26% reduction in winter heat losses when a green roof is used.In addition to this, the plants and soil evaporate water, creating a cooling effect, and a moister air, more comfortable to breathe. Cooling effect is useful at summer, but at winter there is another green roof feature – insulation. The soil layer provides an additional insulation. In warmer climates a green roof especially the versions with thicker soil layer, can make a difference in the heating required in the building. Life expectancy of the root membrane is also important. The waterproofing of the roof, for example bitumen, has a normal life expectancy of 25 years.After that it needs replacing. The reasons are that the uv-light from the sun makes the surface brittle, and then t he expansion and shrinking caused by the fluctuations in temperature, together with the loss of elasticity, causes cracks to form in the membrane. The high temperatures in themselves, above 60 ° Celsius, age the membrane. The green roof protects the waterproofing from both the uv-light and the temperature extremes, increasing the life expectancy of the membrane to at least 60 years. (http://www. greenroof. se/? pid=28&sub=19)One of the most important effects of green roofs in the cities is their potential for retaining and delaying rainwater during storms. The gutters and sewers in the city have to be big enough to cope with the amounts of water that falls during extreme storm events. As more and more surfaces in the built up areas are made hard and impermeable, less water can percolate naturally into the soil. This means that the sewers and treatment plants get higher and higher loads. For the water treatment plant this can be a great problem, since they take care of sewage as we ll as rainwater.If the sewage gets very diluted by a heavy rain, the sensitive chemical and microbiological processes are disturbed. Getting the balance back costs time and money, and in the meantime, sewage is less completely cleaned. Also, the treatment plants cannot store unlimited amounts of water, so during extreme rains, they are forced to let completely untreated water to the natural waters. The more rain water that is taken care of locally, the less often we will have to face these polluting events. (http://progressivetimes. wordpress. om/2010/10/04/one-roof-two-roofs-green-roofs-blue-roofs/) There are some effects which are interesting. The heat island effect. This is the effect that makes cities reach a higher average temperature than the countryside around them. The large amount of stone, asphalt and concrete in the towns and cities that absorb the heat from the sun in the daytime, and release it at night. An additional cause is the lack of trees and other vegetation. The night time temperature rises, and in the summer people suffers from sleeplessness. The cost of air condition goes up.Green roofs can protect from noise and electromagnetic radiation. Thick layers and plants can reduce noise in the outdoor environment and green roofs can reduce the electromagnetic radiation that enters a building to a great extent. (http://www. greenroof. se/? pid=28&sub=19) The most important problem in big cities is pollution. Green roof vegetation, as well as other vegetation, use CO2 for their respiration, and therefore reduce the negative effects of pollution. Best are highly productive plants, which in a year can produce a lot of biomass.An extensive green roof does not produce very much, but intensive ones could. In this case, it might be a question of a small extra advantage, when large surfaces of the cities rooftops are used for vegetation. This is not a method that can be used as an only solution to the problems of pollution and global warming, but togeth er with all the other beneficial effects of green roofs, it is a small step in the right direction. (http://www. greenroof. se/? pid=28&sub=19) Green roofs also provide habitats for plants, insects, and animals that otherwise have limited natural space in cities.In modern city planning, â€Å"green corridors† are planned into the cities, where parks and waterways can connect the city with the surrounding countryside, and get humans in closer contact with nature. In the places where there isn’t enough ground space for green space, the green corridors, and the habitats for animals don’t have to be discontinued, if the flat roofs are used. (http://www. greenroof. se/? pid=28&sub=19) Thus green roof save materials, energy and money, produce less waste, can protect from negative cities impact and what is the most important – is environmental friendly. However, green roof has some disadvantages.Weight is problematical field. A thin extensive green roof of the t ype widely used weighs about 50 kg/m2 when saturated with water. Lighter versions are available, that uses rock wool as substrate instead of soil, which gives a weight of about 35 kg/m2. Compare that to tiles that weigh 33 – 37 kg /m2, depending on the type. If you live in a region where you can expect snow, then weight has to be reckoned as well. So some buildings, especially old buildings, cannot be retrofitted with certain kinds of green roof because of the weight load of the substrate and vegetation exceeds permitted static loading.Depending on what kind of green roof it is, the maintenance costs could be higher. Cost is the main reason why people didn’t want green roofs. Properly designed and -installed systems include root barriers. It is true that installing adequate waterproofing systems and root barriers automatically can increase the initial cost of the roof. A properly designed and installed green-roof system can cost 15 to 20 dollars per square foot as a to tal cost, not including the roof's waterproof layers.In Europe, a well-designed and professionally installed fully integrated green roof can cost anywhere between 100 to 200 euros per square meter, depending on the kind of roof, the building structure, and which plants are used. Despite of that, I think that green roofs have more advantages than disadvantages. (http://en. wikipedia. org/wiki/Green_roof) It is clear that living green roofs and landscapes over structure are not a panacea for ameliorating the negative environmental impacts resulting from increased development or the loss of open space.They cannot and will not replace our forests and prairies, will nor remediate the degradation of all stream corridors, and will not stop global warming by themselves. However, green roofs and landscapes over structure can act buffers to mitigate the impacts of unbridled and unplanned urban growth and development. Reducing building roofs generates less storm water runoff, reduces the heat gain that affects our indoor and outdoor environments, and mitigates the continued degradation of air and water quality. Green roofs provide additional usable, confortable open space. Green Roof Many people don’t know what green roof is. So, what it is? A green roof is not a surface painted green, it is a living surface of plants growing in a soil layer on top of the roof. A thinner or thicker soil layer is spread over the roof membrane itself, sometimes with a protective root barrier, often with a drainage layer underneath. On the substrate, draught-tolerant species of plants are grown. Roof vegetation like this one doesn’t at all damage the waterproofing membrane of the roof. In fact it protects it from the uv-light which does damage the membrane over time.There are two types of green roofs: extensive and intensive. There are some differences of its. An extensive roof has very thin soil layers, draught tolerant plants and requires little or almost no maintenance. The limitation here is in the choice of plants. Extensive roof can be established on a very thin layer of soil. An intensive roof garden has much thicker soil layers, and can look like an ordinary ga rden, with trees and shrubs. Intensive roofs are more park-like with easy access and may include anything from kitchen herbs to shrubs and small trees.This of course needs as much maintenance as a garden does, and can only be constructed on a roof that can bear heavy loads. (http://en. wikipedia. org/wiki/Green_roof) It doesn’t matter what type roof is, but construction is a similar. Construction includes drainage materials, plant materials and establishment methods. For each green roof project, different site conditions and your aims and motives will govern the choice of materials and establishment methods. Therefore, if you are planning to build a green roof, consider the following two sections carefully.There are some roof sections which are important. First is a waterproofing. The membrane is made waterproof, and it will stay waterproof unless it gets physically damaged or aged. What ages a bitumen membrane is mainly uv-light and temperature extremes. Unless the roof memb rane is damaged while laying the green roof, the soil and vegetation cover protects the membrane from these types of injuries later. (http://www. greenroof. se/? pid=32&sub=19) Second section is root barrier. The asphalt waterproofing itself is not classified as root resistant and had to be reinforced with a root barrier.This barrier consists of rubberized asphalt enforced with polyester and treated eight a root-repelling agent. There are also synthetic waterproofing membranes (like PVC liners) available that are root resistant and do not require an additional root barrier. Different countries have different building practices and rules for green roofs – and many countries have no rules at all yet. In Germany, for example, a root barrier is always laid under a green roof. This is to ensure that no roots can damage the waterproofing.A root barrier is sometimes incorporated in the drainage layer. It can be chemical and poisonous to plants, or it can be a thin copper sheet, or r ubber sealed so as to avoid seams. If your motive for having a green roof is sustainability and ecological consciousness, it’s a good idea to ask your contractor about the method. In Sweden, the usual practice is that under extensive roof vegetation (2 – 5 cm soil), where only sedums and moss can survive, an extra root barrier is not considered necessary, since the sedums used have weak roots, and moss has no roots at all.When the soil layer is thicker, and therefore can hold more water, other plants grow there, and there is a risk of getting weeds with more penetrative roots. Second layer is insulation. Insulation boards can be made from extruded polystyrene which has high water resistance and compressive strength. The main difference from the old roof is that the insulation layer must be places above the waterproofing membrane, but on the new roofs insulation must be located below the waterproofing. Second, but not less important, is drainage.The main reason for usin g a drainage layer is that if a lot of water drains off along the surface of the soil, this will cause erosion. The second reason, is that for roofs which are almost flat, too much water would remain on the roof, forming puddles. Especially sedum vegetation is adapted to dry conditions, and tends to rot if submerged. Besides, too much water available can lead to unwanted plants establishing on the roof. Another function of the drainage materials that are often used is to store some amount of water.This effect becomes more and more important the drier the conditions on the roof are, due to climate, a steeper slope or other conditions on the roof. Drainage materials used in green roofs include natural materials, recycled materials and manufactured drainage mats. (â€Å"Green roof systems† Susan K. Weiler, Katrin Scolz-Barth) And finally, the top layer is growing medium with plants. The growing medium provides nutrients and structure for the roots to anchor in. the proprietary m ixes of the manufacturer consist of a lightweight aggregate, expanded shale, and some compost.The organic components make up about three to six percent of the shallow planting areas. The mix for deeper planting areas has slightly more organics. This mix is also heavier and allows a higher water-holding capacity in order to support the larger plants of these areas. In conclusion, one has to realize that there is no cookie cutter approach when it comes to the design of a green roof section. Though certain layers are always present – waterproofing, root barrier, insulation, protection layer, drainage layer, growing medium – their actual composition varies widely responding to a particular situation. â€Å"Green roof – a case study† Christian Werthmann) Green roofs have many advantages. One is a cooling effect. It is very useful effect for individual houses at summer time. A black bitumen roof easily reaches temperatures of 80 ° Celsius in the summer. When a soil layer and the shading plants protect the roof, the surface temperature usually doesn’t rise above the surrounding air temperature. A study conducted by Environment Canada found a 26% reduction in summer cooling needs and a 26% reduction in winter heat losses when a green roof is used.In addition to this, the plants and soil evaporate water, creating a cooling effect, and a moister air, more comfortable to breathe. Cooling effect is useful at summer, but at winter there is another green roof feature – insulation. The soil layer provides an additional insulation. In warmer climates a green roof especially the versions with thicker soil layer, can make a difference in the heating required in the building. Life expectancy of the root membrane is also important. The waterproofing of the roof, for example bitumen, has a normal life expectancy of 25 years.After that it needs replacing. The reasons are that the uv-light from the sun makes the surface brittle, and then t he expansion and shrinking caused by the fluctuations in temperature, together with the loss of elasticity, causes cracks to form in the membrane. The high temperatures in themselves, above 60 ° Celsius, age the membrane. The green roof protects the waterproofing from both the uv-light and the temperature extremes, increasing the life expectancy of the membrane to at least 60 years. (http://www. greenroof. se/? pid=28&sub=19)One of the most important effects of green roofs in the cities is their potential for retaining and delaying rainwater during storms. The gutters and sewers in the city have to be big enough to cope with the amounts of water that falls during extreme storm events. As more and more surfaces in the built up areas are made hard and impermeable, less water can percolate naturally into the soil. This means that the sewers and treatment plants get higher and higher loads. For the water treatment plant this can be a great problem, since they take care of sewage as we ll as rainwater.If the sewage gets very diluted by a heavy rain, the sensitive chemical and microbiological processes are disturbed. Getting the balance back costs time and money, and in the meantime, sewage is less completely cleaned. Also, the treatment plants cannot store unlimited amounts of water, so during extreme rains, they are forced to let completely untreated water to the natural waters. The more rain water that is taken care of locally, the less often we will have to face these polluting events. (http://progressivetimes. wordpress. om/2010/10/04/one-roof-two-roofs-green-roofs-blue-roofs/) There are some effects which are interesting. The heat island effect. This is the effect that makes cities reach a higher average temperature than the countryside around them. The large amount of stone, asphalt and concrete in the towns and cities that absorb the heat from the sun in the daytime, and release it at night. An additional cause is the lack of trees and other vegetation. The night time temperature rises, and in the summer people suffers from sleeplessness. The cost of air condition goes up.Green roofs can protect from noise and electromagnetic radiation. Thick layers and plants can reduce noise in the outdoor environment and green roofs can reduce the electromagnetic radiation that enters a building to a great extent. (http://www. greenroof. se/? pid=28&sub=19) The most important problem in big cities is pollution. Green roof vegetation, as well as other vegetation, use CO2 for their respiration, and therefore reduce the negative effects of pollution. Best are highly productive plants, which in a year can produce a lot of biomass.An extensive green roof does not produce very much, but intensive ones could. In this case, it might be a question of a small extra advantage, when large surfaces of the cities rooftops are used for vegetation. This is not a method that can be used as an only solution to the problems of pollution and global warming, but togeth er with all the other beneficial effects of green roofs, it is a small step in the right direction. (http://www. greenroof. se/? pid=28&sub=19) Green roofs also provide habitats for plants, insects, and animals that otherwise have limited natural space in cities.In modern city planning, â€Å"green corridors† are planned into the cities, where parks and waterways can connect the city with the surrounding countryside, and get humans in closer contact with nature. In the places where there isn’t enough ground space for green space, the green corridors, and the habitats for animals don’t have to be discontinued, if the flat roofs are used. (http://www. greenroof. se/? pid=28&sub=19) Thus green roof save materials, energy and money, produce less waste, can protect from negative cities impact and what is the most important – is environmental friendly. However, green roof has some disadvantages.Weight is problematical field. A thin extensive green roof of the t ype widely used weighs about 50 kg/m2 when saturated with water. Lighter versions are available, that uses rock wool as substrate instead of soil, which gives a weight of about 35 kg/m2. Compare that to tiles that weigh 33 – 37 kg /m2, depending on the type. If you live in a region where you can expect snow, then weight has to be reckoned as well. So some buildings, especially old buildings, cannot be retrofitted with certain kinds of green roof because of the weight load of the substrate and vegetation exceeds permitted static loading.Depending on what kind of green roof it is, the maintenance costs could be higher. Cost is the main reason why people didn’t want green roofs. Properly designed and -installed systems include root barriers. It is true that installing adequate waterproofing systems and root barriers automatically can increase the initial cost of the roof. A properly designed and installed green-roof system can cost 15 to 20 dollars per square foot as a to tal cost, not including the roof's waterproof layers.In Europe, a well-designed and professionally installed fully integrated green roof can cost anywhere between 100 to 200 euros per square meter, depending on the kind of roof, the building structure, and which plants are used. Despite of that, I think that green roofs have more advantages than disadvantages. (http://en. wikipedia. org/wiki/Green_roof) It is clear that living green roofs and landscapes over structure are not a panacea for ameliorating the negative environmental impacts resulting from increased development or the loss of open space.They cannot and will not replace our forests and prairies, will nor remediate the degradation of all stream corridors, and will not stop global warming by themselves. However, green roofs and landscapes over structure can act buffers to mitigate the impacts of unbridled and unplanned urban growth and development. Reducing building roofs generates less storm water runoff, reduces the heat gain that affects our indoor and outdoor environments, and mitigates the continued degradation of air and water quality. Green roofs provide additional usable, confortable open space.

Medicine and City Life

In addition, in a big city you can enjoy the best service and entertainment. Because there are many rich people here, they can invest much money to get the best for them. Lives in a big city are quite luxurius but you don't have to be worried when you are sick or suffer a disease because there you can find good doctors for you, as long as you have much money. Advantages and Disadvantages of the Village Life and City Life Sometime you may be think, the city life is better than village life. However there are so many advantages and disadvantages in city life and village life. Actually the city life is more comfortable. As well as there are more opportunities for people to progress in their lives. There are a lot of facilities for people in the city and they have more opportunities for making money. When a person falls ill there are good government and private hospital in the city to get treatment. There are large shop complexions, banks, offices, cinemas, hostels, clubs, hospitals etc. in and around the city. People in the city have better transport facilities than the village. More and better medical facilities: In a city people get more and better medical facilities than the people of village. In a city there are more hospitals and clinics . there are more qualified doctors in a city. In city you can find different health facilities like different government and private hospitals , but in village you cannot find more health facilities. ’ the town areas provide people with better facilities as far as health services are concerned. Cities also provide ample medical facilities. In every city, there are good hospitals in which the poor get free medicines and treatment. Many well-qualified private doctors are also there to serve the sick and the suffering. Lack of such medical arrangement is a drawback of villages. the city to be better in the long run as there is better access to health care facilities and quick availability of round the clock emergency services. However, the kind of health