Laziness through Technology Essay

Technology is the branch of knowledge that deals with the creation and use of technical means and their interrelation with life, society and the environment. Modern inventions have made people lazy because they make things easier. In a BBC News article, Dr. Richard Weiler and Dr. Emmanuel Stamakis argue that technology in the form of energy saving devices like remote controls, has led humanity to an inactive lifestyle which poses risks to people’s health. Dr. Stamakis said, â€Å"Sedentary living is the most prevalent disease, silent killer, and greatest health threat facing developed countries.† Technology inventions have also reduced humans’ physical activity, making them lazy. Technology governs the lives of people especially children (Wise, â€Å"Does technology†¦Ã¢â‚¬ ). see more:technology make us lazy Web search engines like Yahoo, Google, and Bing have changed the way youth learn and remember information according to a study by Department of Information Management. Having practically all the information they could ever need has caused students to subconsciously not store away as much data, scientists claim. Researchers have examined the role of the internet in changing the nature of human memory. For instance, students forget things they are confident they can find online, while likely to remember things they think are unavailable online. Due to the excessive usage of online chatting and shortcuts, the writing skills of today’s young generation have declined quite tremendously. These days, children are relying more and more on digital communication that they have totally forgot about improving their writing skills. They don’t know the spelling of different words, how to use grammar properly or how to do cursive writing. (Oliveira, â€Å"is technology†¦Ã¢â‚¬ ) . Today experts call them the M2 Generation—highly technological children whose lives seem to revolve around the media. With the constant exposure that children have to television, computers, mobile devices, and video games, it seems there are no limits to the amount of time children spend with technological devices. According to a survey cited by Brian Wallace, in just five years, media use has increased from six and a half to nearly seven and a half hours a day in children between the ages of eight and eighteen. Even more alarming, children have become masters at multitasking, often using two or more media devices at the same time. Counting each device separately, these kids have found a way to cram in a total of 10 hours and 45 minutes of media content into those seven and a half hours. These findings epitomize the very phase â€Å"media saturation.† Children now spend more time with technology than they do with their family, in school and sleeping. These have adverse effects on children’s performance in school(Wallace, â€Å"The effect of†¦Ã¢â‚¬ ). Furthermore, 16% of children that are between the ages of six-nineteen years old are overweight or obese, a number that has tripled since 1980 mostly due to electronic usage. Being overweight can bring with it great health concerns. Many of these children have a good chance of developing Type II Diabetes, asthma, sleep apnea, social discrimination, high cholesterol and/or blood pressure. Also, according to a Stanford University of Medicine study, elementary students consume 20% of their daily calorie intake while watching television, which usually includes unhealthy snacks, largely due to advertisements for junk food and boredom. Coincidently, kids are not burning off any of these calories while they are plopped in front of the television (Wallace, â€Å"The effect of†¦Ã¢â‚¬ ). Similarly, spending hours in front of screen, whether it is a television or computer, can quickly contribute to a serious decrease in the amount of physical activity a child gets during the day. A child needs at least 60 minutes of physical activity each day to maintain a healthy weight and level of fitness. The more technology time a child engages in, the less the child daily dose of physical activity will be. This can in turn contribute to negative effects such as weight gain. Also, televisions, laptops, tablets, cell phones, iPod and all of the other technological devices that children use, they are constantly inundated with an array of media images these often include negative behaviors such as underage drinking, drug use or risky sexual situations. With the use of technology the media portrays an idealized image of the teenager when it comes to weight and appearance (Loop, â€Å"Exposing the negative†¦Ã¢â‚¬ ). Furthermore, technology has a bad effect in the Environment, old electronics are dumped into landfills and these can lead to toxins such as lead, mercury and lithium into the environment. Electronics account for two percent to five percent of the trash that reaches America landfills every year. According to a Green Citizen, a California based company that works to reduce waste, an average computer screen contains up to eight pounds of lead, which in excessive amount can cause nerve disorders and joint pain in adults and high level of lead in children has been associated with brain damage and anemia (Stanic, â€Å"Bad effect of†¦). Also, modern technology is affecting people’s sleep. The artificial light from television and computer screen affects melatonin productions and throws off circadian rhythms, preventing deep, restorative sleep. A research by Sara Thomas shows that heavy cell phone use showed an increase in sleep disorders in men and an increase in depressive symptoms in both men and women, men who use computers intensively were more likely to develop sleeping problems., regular, late night computer use was associated with sleep disorders and stress in both men and women. The relationship between stress, sleep disorders and depressions has more to do with the overuse of technology in our society, especially among young people (Volpis, â€Å"Heavy techno†¦Ã¢â‚¬ ). Top of Form Today, computers do this job instead of workers, with the rise in technology, many jobs that require little skills have been replaced by computers and machines. This is a type of structural unemployment. An example of this is the supermarket checkout systems. Initially many cashiers were employed by supermarkets, with a majority of these people being aged under 24. With the introduction of the computer checkout systems, these cashiers are now in less demand and has created more unemployment, particularly amongst the youth. The developments of the internet and online shopping have significantly reduced the number of retail workers. In society today literally anything can be bought online. These types of unskilled jobs were again predominantly taken up by under 24 year olds who were using these jobs to fund their education (U.S. Department of Labor 2004). Moreover, the internet has stripped the world of privacy. Long gone are the days of having an unlisted telephone number and staying offline to keep your information safe from prying eyes. A few flicks on a keyboard can help average person to find anyone’s address and contact information. Those with more sinister intentions, the use of phishing, viruses and hacking helps to find any information they wish to obtain. Plus, people have no sense of privacy online. They do not think twice about twitting every move they make, freely giving out their location on Google Map and putting their entire life story on Facebook. The evidence is overwhelming technology has caused isolation, lack of social skills, bad writing skills, poor sleep habits and laziness. Works Cited Loop, Erica. â€Å"Exposing the negative effects of technology on kids.† Global post 15 March 2012. Web. 25 March 2014. Mart, Coollen. â€Å"Technology making us lazy.† Inside Technology 4 October 2010. Web. 25 March 2014. Olivera, Micheal. â€Å"Is technology hurting us by making life easier.† The Canadian Press 27 December 2012. Web. 25 March 2014. Stanic, Claudia. â€Å"Bad effects of modern technology in the environment.† eHOW. 17 November 2013. Web. 2 Wallace, Brian. â€Å"The effect of media and technology on young children.† Social Media Today Wise, Jon. â€Å"Does technology make us lazy.† SIOW. 17 September 2013. Web. 25 March 2014. Volpi, David. â€Å"Heavy technology use linked to fatigue, stress and depression in young adults.† Huffpost 8 February 2012. Web. 25 March 2014.

Investment and Debt Capacity

Stock Repurchase Repurchase of stock can be viewed in each of the following way: investment, financing, shareholder distribution and control issue. Repurchase of stock can be a way to use firm’s excess debt capacity. By doing so, firm can lower the cost of equity financing. If debt financing is more flexible and cheap, replace equity financing with debt financing is a good way to lower the weighted cost of capital. In this sense, such action is a financing issue because it controls the cost of financing. On the other hand, repurchase of stock can adjust shareholder distribution.If shareholders consist of most individual investors, they may require more dividends or other forms of profit sharing. Firm can repurchase stocks from such investors so that they can adjust their dividend policy. If management holds few shares of the company, they may lose their control over operating and strategy decisions. By repurchasing stocks, management could regain majority control over the comp any on strategic decisions. Finally, repurchase of stock is also an investment issue because it enables the firm to increase its return on equity by eliminating dilution effect.Higher return on equity will attract more favorable investors as well as better vendors. It has the same outcome of investing in businesses, so it can be viewed as an investment. Debt Capacity for Stock Repurchase From Exhibit 5, we get the total debt of Marriott at the end of 1979. We define total debt as sum of short-term loan, current portion of long-term debt, senior debt and capital leases. The average market price of Marriott in 1979 was $14. 9, and interest rate for Baa corporate debt was 12%. We assume that Marriott would repurchase stocks at price of $15 using 12% debt financing.Marriott used Adjusted EBIT over net interest as a measure for debt capacity, so we use such measure as well. The table above shows the main assumptions we make in the analysis. Before the stock repurchase, EBIT adjusted/Net interest rate was 6. 64, above the 5 times threshold Marriott set for itself. Because the net interest before repurchase was $27. 8 million, we conclude that adjusted EBIT was $184. 59 million. In 1979, additional debt from repurchase was $159 million, making the total debt $538. 83 million. Net interest after repurchase is the original net interest plus the 12% interest from new debt.Based on such analysis, the new adjusted EBIT/Net interest ratio is 3. 94, which is lower than 5. So we conclude Marriott may not have enough debt capacity to finance the stock repurchase. We further perform a scenario analysis. Suppose Marriott had just enough debt capacity, which means new adjusted EBIT/Net interest ratio equals 5. We find that repurchase price should be $7. 17 so that Marriott could utilize its debt capacity fully. We conclude that a repurchase price under $7. 17 is in fact transferring value to remaining group because they can share more future profits resulting from the concentrat ed equity.Yet a repurchase of $15 is way above $7. 17, which means selling shareholders have more value because they are compensated with higher return. Owned vs Managed Marriot has two options about the operation of hotel chains. First, it can own the hotel and enjoy the profit margin. Second, it can sell the hotel but retain management contracts so it controls the operation of such units. Following is the detailed decomposition of costs associated with two options. According to Exhibit 9, in 1978 the typical cost for a hotel room consists of improvement cost, furniture, fixtures and equipment cost, land cost, pre-opening cost and operating cost.For an owned hotel, Marriot had to pay the total cost for running the property, but if it is managed, Marriot only had operating cost because the buyer was responsible for the maintenance. In an attempt to emphasize more on return on invested capital rather than margins, Marriot sold some of their existing hotels and retained management con tract to free up capital. Managed hotels had operating margin of 8%-10%, while owned had 15%. We assume 10% margin for managed hotels and 15% for owned hotels.To decide when to sell the property, we analyze the remaining present value of future cash flow of a hotel at different point of time in its life cycle. We further assume that when the hotel is sold, the selling price is set so that present value of future cash flow equals the 10% margin. We assume $50 revenue per room night of a typical 150-room hotel, and one year has 360 days. Sales level for each year in the life cycle connects to the occupancy rate. From the graph of Exhibit 9, we get different occupancy rate for the whole life cycle. It reaches the peak 100% at year 8, and after year 10, it declines almost linearly to 10% in year 30.We can see that if Marriot sells the hotel before opening, the selling price would be $1. 63 million at time 0. After the peak, let’s say, year 9, the selling price would be $ 1. 55 mi llion at time 9. We can also see that in fact the max value of PV is at year 4, which has $2. 85 million in PV at 15% margin. Marriot would free up more capital if it sells the hotel before opening, but instead it would lose more operating profit. If Marriot is in short of capital, it could sell the hotel up-front so that the freed up capital can be invested in other profitable projects.Selling after the peak is a good choice if Marriot wants to enjoy the increasing operating profit before the peak. Shareholder value can be added if the return on freed-up capital exceeds the profit loss from selling the property. Recommendation Based on our analysis, we would recommend the company to investing in their core business to fully use their debt capacity. Since Marriott’s debt capacity is only able to repurchase 10. 6 million shares at a price significantly lower its current trading price (according to Exhibit 12). It is unlikely the repurchase strategy would take place as expected .The negative impact of false interpretation that the Marriott has reached its growth limit may not be offset even if the repurchase take place. To decide whether to invest in core business or diversify by acquisition we take a look of the hotel’s current state. The company now is operating in four main sectors, hotel group, contract food service, restaurant group theme parks and cruise ships& other. Based on exhibit 3, all of MC’s sectors are doing well in the past few periods; Hotel group is still the main profit sector account for 51% of the total operating profit and 16. % of the gross margin. Theme park and restaurant sectors have contributed a lot to total revenue but at the same time involve more risk. The asset associated with that new business couldn’t be mortgaged easily. Marriott’s theme park alone was estimated to cost 80 million but double of the estimation eventually, the investment made MC to lower its debt credit level. If we use the extra debt capacity on acquisition of new business, there could be a higher risk of availability and cost of long-term debt financing, which may cause MC to lower its debt credit even lower and increase its defalt risk.As a company mostly processioned in hotel management, invest in new businesses that required new management style also increases MC’s operating risk. Marriott’s hotel business has positioned itself to operate for customers whose travel plans were less subject to change than those of vacationers. Its historical operation has showed steady healthy growth even in recessions. Most of the sector’s assets are real estates and tends to appreciate over time rather than depreciate, it is easy to issue debt secured by hotel assets. Prevailing trends also indicate sighs of need of rapid room expansion.As MC’s major competitors Hilton and Holiday Inn are shifting their core business to a more diversified market, keep focus on core hotel business enable MC t o maintain its own competitive advantage in operation. Overall we would suggest MC to use its excess debt capacity to invest in existing hotel with some clientele base but lower entry cost where the Marriott‘s acquisition can significantly improve the operation. To invest in such assets, there is low research and construction cost but easy to manage with sustainable growth. We believe that the best investment for corporation would be investing in the existing business.The hotel business was the most promising area for Marriott’s Corporation. When MC’s competitors expand their business into gambling and casino ventures, MC was more likely to expand in the traditional market. To invest in the hotel business, a large amount of external financing is needed. A large amount of Marriott hotels were managed rather than owned by the MC. Despite the MC could limited capital investment by holding the equity up to 50% so that they could increase the opportunity to be awarded the management contract, they might still need to cost a lot in investing more hotels. MC could also choose to expand their existing hotels.Those hotels have higher occupancy rate and higher local demand. Doing this expansion will need full capital investment in property. With high growth rate of hotel rooms, this investment seems valuable. However, this way of investment still needs large amount of external financing to support the expanding. Even though MC’s new hotels are profitable in the end, the cost of developing hotels is still required a big financing. In addition, due to the increasing inflation rate, the cost of equity and the cost of debt increased. Therefore, as inflation rate becomes higher, the unused debt capacity becomes less in the future.

Global Security: Weapons of Mass Destruction Essay

Since the Cold War, introducing nuclear weapons into the global system was one of the biggest changes that created a global phenomenon even after the year 1945 to the contemporary global politics. It has shaped the crucial aspects of the strategic actions of the states and transformed the international system. After experiencing two catastrophic global conflagrations, the global system has not triggered major wars and intra-regional wars over the post-Cold War period. However, utilising nuclear weapons to prevent world war should be treated with great attention as there are prospects of nuclear proliferation globally. The traditional definition of security is being freedom from danger and risk. However, in this context of the global politics, it perceives ‘security’ as something that makes protection and creates sense of safeness. Thus throughout this essay, it will discuss the meaning of security in the means of how it was created through the influence of nuclear/ weapons of mass destruction (WMD). Firstly, it will analyse the changing attitudes of strategic studies post-Cold War in the developments of nuclear technology proliferation. Moreover, it will critically discuss the influences of the nuclear weapons towards the security model in relations to why states still seek to develop weapon of mass destruction (WMD) in the contemporary global politics. Understanding the terror and recognising of the destruction capabilities of nuclear weapon in the contemporary era can be a challenge to the people of today as the last nuclear weapon detonated in 1945. Subsequently, it is important to observe the historical context of WMD development and study the intention of the WMD. 1940 was the year of the birth of the first nuclear arsenal named as ‘Ivy Mike’. American physicists and their leader Edward teller developed nuclear armaments that was first detonated in 1945, (Balogun, 2011 p. 160) which was defined as; extreme scale immediate mass destruction. The strategic studies of the international relation have drastically changed in the past 20 years. Steve Smith’s The increasing insecurity of Security Studies: Conceptualising Security in the Last Twenty Years (1999) examines some aspect of security study literature in the last two decades. Smith addresses his main analyses of the changed perspective of the core subject nitially concentrated on state and military to human social security. His view of what it is called the security studies in the contemporary system, moves away from the concentrating on the aspect of the military, WMD as the dominant issue but argues that the crucial issue is human security. On the other hand, Andrew O’Neil (2009) approaches the study in different perspective as he argues that WMD continues to act as the central role in international relations and in security studies as still in the contemporary system numerous states continues to value nuclear weapons as the supreme strategic possession for their security. Synder (2000 p. 174) has given the two variables for explaining the dynamics of nuclear proliferations. The operative growth of nuclear arsenals among the superpowers can be identified as ‘vertical proliferation’. Furthermore, significant potential for the spread can be recognised in other technologically capable states to develop nuclear technology and this is recognised as ‘horizontal proliferation’. Increase in producing nuclear technology and actions of testing have developed public’s eye catching concern, which is in relations to both military and environmental crisis. In generating nuclear power into the state it builds the sense of both security for the state conversely insecurity for human and the environment. Acknowledging the power of state after possessing nuclear weapons will definitely achieve security against external threat, nevertheless it is crucial to consider the aspect of economic effect on the state. In obtaining nuclearization, the state must have the capability in economic and technological terms. Developing researches and building nuclear arsenal are phenomenally expensive even to sustain, whether the state is able to begin to build nuclear weapon programs, if the state is incapable to maintain their program effectively it would lead to the chances of misleading the program, thus may cause major threat to its own state. Moreover, nuclear arsenals under the programs can lead into the hands of the ‘rouge state’ (2000 p. 159). External threat of bribery from other rouge states can follow after the financial struggle of opening of the bureaucracy. In the past states have failed to sustain the nuclear system as it is outstandingly costly, Soviet Union is one the example that diminished nuclear program due to lack of finical hold up. In this case, the state should pursue for other survival resources to provide security for their people, for instance; environmental sustainability and enhanced agriculture. Neo –classical realist assesses the state’s power and examines of the consequences of the nuclear proliferation, on why the state pursue changes in its power in relations to their declining power position in the global system. Leaders and decision makers of their states are afraid of the strategic costs in their own actions in trying to achieve further and superior security. The NMD not only profoundly stresses the status quo (2000 p. 171), but it also threatens to create an incongruous actions to other states to produce or prepare a similar level of power of security to counter the external threat. Thus it generates a certain situation as known as; ‘acute security dilemma’ or a ‘cascade’ of nuclear proliferation, â€Å"an increase in one state’s security decreases the security of others† (Jervis, 1993 p. 8). The states facing security dilemma are determined by the given factors of their geographic size and location, power of their equipped military and strategy. These factors are expected to manipulate the position of the state in the international system by means of security threats. Security dilemma actively elevates up and down the chances of conflictions between states, hence it shapes balancing strategies. In comprehending the occurrence of nuclear proliferation, it is important to understand the theory on why states pursue nuclear power. In the means of security, constructivist have presented an insight on how to analyse the question of ‘‘How nuclear weapon technology mean different things in different places and times’ (Rogers, lecture), constructivist states that it is challenging to determine with the absence of calculating and the perceiving into giving attention to cultural, social and historical context of the state to how the definition came to assessable. Thus, it is important to develop an understanding of the purpose of WMD in the international system, with the question of why states seek to build nuclear power. Numerous realist and non-realist scholars consider the ‘security model’ as the standard justification for occurrence of nuclear proliferation (Sagan, 1997). According to the security model states will, â€Å"develop nuclear weapons when they face a significant military threat to their security that cannot be met through alternative means. † (1997 p. 54) Established on Waltz’s theory of neo-realism, a limited, although persuasive part of the realist theory; the security model was derived initially from the original thought of balance of power. He puts forward his thought that states involves in competitive strategies for insure of their security and survival. In the short term, it is anticipated that states will weigh against from the changes in relative power that destabilise their position in the global system, externally by unifying with a nuclear armed state or internally by developing nuclear technology themselves. Further looking at the long term, states are likely to develop nuclear arsenals through imitating after observing an effective but also successive strategy attempted by states. Sagan concludes that almost all the judgments to develop nuclear arsenals â€Å"appear to be best explained by the security model† (1997 p. 85). Consequently, the security model addresses a persuasive explanation regarding the theory nuclear proliferation. Three specific models are introduced in explaining the incongruous impact of nuclear proliferation; why states seek to build nuclear weaponry, in Sagon’s article, ‘Why Do States Build Nuclear Weapons? Three Models in Search of a Bomb’ (1997). Security model of ‘nuclear weapons and international threat’ is the first model Sagon introduces. According to the neorealist, the international system is an anarchy which is driven by the threat of nuclear weapons where states are to equip for preparation for conflict. Absence of authority in the system, states can desire to choose to achieve self-help. However in spite of authority, there are strong and weak states that separate which states are capable of obtaining more power through nuclear weapons. The three factors are crucial in the makeup of a strong state, they are; powerful military, economy and politics. As mentioned earlier, security dilemma is a result of proliferation but also in vis a versa producing a chain reaction, Sagon believes that ‘From this perspective, one can envision the history of nuclear proliferation as a strategic chain reaction’ (1997, p. 58). The previous model could not offer the whole explanation which the second model could explain whole reason why states pursue to develop nuclear weapons. The second model is, domestic politics model, it focuses on who encourages and discourage the state government to develop WMD. Within the domestic level Sagon explain that there is also a chain reaction and maps out who governs the state to process of developing nuclear arms, Sagon says, ‘the acquisition of nuclear weapons †¦ is likely to serve the parochial bureaucratic or political interests of at least some individual actors within the state’ (p. 63). In contrast to the security model, the causality is not ‘unidirectional’ (Rogers, 2012 lecture) but further complexity follows as it activates at the level within the state. The last, third model that Sagan study is the norm model which addresses states as unitary actors and it concentrates on norms in reference to the possession of nuclear arsenals. It peruses to apprehend the role of nuclear weapons symbolically and argues that state’s actions are ‘determined by common beliefs about which actions are appropriate in the international community’ (p. 73). As a final point, the last model seeks to envision the forthcoming future for the potential of non-proliferation era. The three models by Sagan have explained and provided a perception on the theatrical justification of nuclear proliferation on the reason behind states would seek nuclear power for the ultimate power for threatening external states. The studies of the three models demonstrated an aspect on how possession of a nuclear weapon can change the system drastically internally and externally through the distortion of the balance of power. Nonetheless, these models have also given the truth about the consequences that ultimate power can be achieved however; nuclear weapons will not necessarily provide or elevate complete state security. In actual fact, this security practice also accompanies insecurity where the contemporary international system in presence of nuclear proliferation it is a challenge not to face security dilemma. The ongoing nuclear proliferation is one of the distress issues in the international system. The movement of the proliferation alters the balance of power between the states creating a possible eruption in the system. An example in the contemporary politics, North Korea has obtained nuclear and missile technology and have directed bomb testing which have intensified the tension between the two Koreas (2009). Moreover, North Korea’s uncertain internal political activities may have created falsifiable knowledge, however this clearly demonstrates the security dilemma in the states surrounding as well as the allied superpowers are caused in the consequences of contemporary proliferation. In 1970, the regime of the Non-Proliferation Treaty (NPT) entered the international system which became the central focus in the non-proliferation organisation. It is a prime structure of managing the spread of nuclear weapons in the international system. It is designed and bounded built from expectations by policy makers in solving security dilemma. The NPT operates as a normative regime, the treaty seeks to challenge why or why not state choose to build nuclear weapon but also examines state behaviours and perceptions in the state in accordance to their nuclear power (2000 p. 175). The NPT is influential and conspicuous in shaping the thought of policy makers and leaders of the state to determine whether the state should develop nuclear technology or not, allied or independent or as for energy provision. Most importantly, it determines and suspects the validity of a nuclear armed state as well as their maintenance. Moreover, it is an arrangement between nuclear armed state which have agreed to nuclear materials and technology transmission to a non-nuclear armed state for peaceful determination, then this state obligate themselves to utilise nuclear materials and technology only for peaceful purposes and not dissuade its primary purpose to develop nuclear weapons (Bosch, 2007 p. 16). According to the NPT, the current situation in North Korea and Iran are in the case of being outside of the normative framework. Only those state who act inside the normative framework are reflected as a proper state, states that are outside the framework are considered as an improper state and these states are recognised as ‘rouge states’ (2000 p. 159) From this, it is clear to vision the influential power of NPT in the international system in shaping state’s actions. Various debates have risen in regards to its unbalanced regime by the NPT. In respect to the military rules NPT have regulated a biased and unequal military regime labelled as â€Å"imperial like imbalance† (Kissling 2008, p. 30). It is states that NPT lacks in some aspects of definite responsibility and keeping the timeframe to discharge nuclear weapons. Though NPT is considered influential, its role in accomplishing complete disarmament, negotiations in the international system has not been an effective control. Organisations and treaties such as Comprehensive Nuclear Test Ban Treaty Organisation or the Fissile Material Cut off Treaty hardly enacted policies. Primary time of the NPT regime, many states imposed the NPT’s disarmament commitment on nuclear technology through the prevention of aircraft and ship transports holding nuclear materials from entering the state boundaries. However, prohibition of nuclear armaments was infrequently imposed. Thus, lack of strict obligations, have made perpetual actions of nuclear proliferation within the states, including rouge state, which is still persists so far in the contemporary politics. 2008, p. 31) Furthermore the NPT authorized nuclear armed states to conduct ‘peaceful nuclear explosions’ and in military purposes to experiment nuclear weapons, all below level zero. Comprehensive nuclear test ban treaty was finally enacted in 1996 and prohibited these actions of testing or detonating any nuclear weapons. Most importantly, states from NTP that possesses nuclear armaments and non-nuclear armed states have not yet ratified or signed for the NPT. Hence, NPT still lack in the requirements to enter the international force. Consequences of these unresolved of complete disarmament by the NPT or any other non-proliferation regime, the threat of nuclear weapons will continue to rise and sense of fear and insecurity will continually follow The study of the structure, development, and history of the non-proliferation regime, analysing some of conflicting attitude to the issue has led to recognise that this contemporary politics are in a period trapped by the growing dangers. Give the impression that more than ever, the regime of proliferation will continue to arise to be more powerful; however understanding of nuclear behaviour has limits as nuclear power also carries both great senses of security and insecurity for the state (Synder, 2000, p. 189). Nuclear weapon alone carries great amount of complexity. There it challenges external states, policy makers and leaders in determining nuclear armed state’s motivation and its behaviour especially rouge states attaining nuclear arsenals. There are two paths in regards these consequences in the future; a state can strive towards or away from nuclear weapons. Non-proliferation and disarmament will occur as there are perspectives on states denuclearising due to the fall any of politic, economic, and military factors. Proliferation may continue due to the chain reaction of security dilemma encircling insecurity in the international system. Thus this has developed critical thinking on why states still choose to pursue nuclear technology in the contemporary politics. Security models pointed by Sagan are filters to understand the theology of nuclear proliferation. WMD has challenged the thought on international security in the contemporary politics as the studies still haven’t settled with a definite answer of when the complete non-proliferation era will arrive, before then the sense of insecurity through security dilemma will encircle the international system.

Strategic Management Analysis - Based on case study Essay

Strategic Management Analysis - Based on case study - Essay Example Better Place opened its first car demonstration center in Israel back in February 2010. The opening of the demonstration center helped the company in showcasing its ambitious plan in challenging the status quo in the rigid and complex industry. The performance of the company has since been outstanding with the formation of partnerships and increased capital funding. Strategic purpose: Mission, Values and mission The mission of the company was to reduce and eventually eliminate oil dependence of the automobile industry. The company aims at reducing the associated health, political and environmental issues that arise from the dominance and ubiquity of internal combustion engine (ICE). The increasing number of vehicles around the globe that have high emission of carbon monoxide and hydrocarbons from the use of oil is responsible for the greenhouse gas emissions. With the growing ratio in the world populations as well as the demand for personal transportation, the environment and economi c sustainability of an ICE dominated transportation sector is highly likely to increase The company aims at attaining a widespread adoption of electric vehicles (EVs) by the creation of links between battery companies, car companies, utilities and consumers. The strategic objective of the company is to take over the market on product performance and delivery of quality and emission free cars to the consumers. This involves having a broader and deeper use of technological capabilities and they believe that the solution to electric cars does not lie in re-engineering the battery but in the re-engineering of the car. Stakeholder analysis Shareholders all those groups of individuals or individuals who depend on a given organization in order to fulfill their goals where the organization ends up benefiting. The main stakeholders of Better Place are the consumers, political groups, suppliers and competitors (Johnson, Whittington & Scholes 2011). Stakeholder management is very high in Bette r Place as they have been factored into the development of Electric Vehicles. For example, Shai Agassi the founder of Better Place believes that overcoming the problem of limited mobility is the only way that consumers would be enabled to adopt the Electric Vehicles (EVs) on a massive scale. The different stakeholders for Better Place influence each other in a positive way. The electric vehicle solution has made provisions and considerations of all the stakeholders. The political stakeholders include the state. For example, the State of Hawaii has launched a Clean Energy Initiative that is aimed at the development of clean energy alternatives by 2030. Adoption of EVs in the State would be the best clean energy alternative for people. This has had positive impacts on the consumers, suppliers and competitors. For the consumers, the move by the state will lead to the reduction of risks which results from carbon monoxide emissions and to enhance adaptability and flexibility. Maintenance costs of electric vehicles are much lower than the ICE vehicles for consumers. It is a social, economic and ethical responsibility for companies to produce and manufacture those cars that will not cause any environmental harm. Better Place owes this to its stakeholders hence the reason for the EVs. External environment analysis The macro-environment (Porter’s 5 forces analysis) Supplier power- There is few suppliers in the supply of electric vehicles around the globe. Better Place is a powerful supplier due to the

HR AND LEADERSHIP Essay Example | Topics and Well Written Essays - 3000 words

HR AND LEADERSHIP - Essay Example DuBrin (2011) have pointed out that organizational change is organic in nature, which means that leaders and managers need to ensure that the change process includes the employees in the organizational rather than banking on resource and process deployment. Hence, it can be surmised that change management is direction oriented process, which means that, managers and in some cases leaders need to take the responsibility to move the organizational change. On the other hand, research work of DuBrin (2011) shows that organizational change can be three types, 1- strategic- which is relatively low human resource driven, 2- tactical- which is relatively high human resource driven and 3- operational- which requires extensive amount of human resource involvement. Careful observation of the research work of DuBrin (2011) shows that, whatever the strategic orientation of change management, one thing remains constant that is the involvement of managers and leaders for giving the direction to the change. Research works of previous research scholars regarding organizational change and role of leaders have forced the researcher to raise a pertinent question, is there any strategic relationship between leadership dimension and success of organizational change management process? Well, throughout the essay, the researcher will try to find answer of this question with the help theoretical argument of various research scholars and in some cases taking help of real world business cases. At this point of the essay, one thing needs to be clarified that the essay will not use any subjective view to establish the relationship between engagement of leaders and success of change management rather the study will take conjectural view on the research topic. In the next part, the study will try to understand different aspects of change management process. It is essential to know why an organization changes in order to understand how leaders and managers can help the organization to incorpo rate the change. Understanding the macro dynamics of change can help the researcher to understand why some organizations implement successful change management process while others fail to do so. The question may arise that is there any magic formulae or special skill which bifurcate winners from losers in context to change management process. Tichy (1983) has identified that leader’s capability to cope with macro environmental challenges and use organizational learning concept in order to change the existing system. According to the research work of Tichy (1983), leaders and managers need to identify three forces such as economic forces, cultural forces and political forces in order to incorporate organizational change in accordance with the magnitude of these three forces. (Source: Tichy, 1983) According to the above mentioned triangular model, organizations develop three types of systems such as technical systems, cultural systems and political system in order to incorpora te change. Gone are the days when organizations can expect that it would achieve competitive advantage by using age old technologies. Organizations have understood the fact that they need to integrate state of art technology in order to deliver better value proposition to customers, decrease cost of operation, and achieve economies of scale etc. The study will use the example of Toyota

Decision-Making Process, Communication Errors Coursework

Decision-Making Process, Communication Errors - Coursework Example Such reaction entails critical thinking. In addition, utilization of the nursing process aids the nurse in thinking and adopting priority steps for the sake of patient care. The nurse incorporates steeps of problem identification and assessment, coming up with goals and interventions to curb the problem, intervening and evaluating whether the goal were achieved to the best level. The goals must be specific, measurable, achievable, realistic and time bound. Proper decision-making improves the patient care, making it holistic and hence decreasing the hospital stay through quick recovery (Dowding & Thompson, 2013). Communication errors in nursing arise when there is inappropriate handing over between shifts. In such case, there is a breakage in the continuity of care provided to the patients. There is fragmentation of care and decreased satisfaction to the patient. The result is poor healing and over hospitalization leading to death. During reporting and handing over shifts, wrong information may be passed regarding certain patients. It has direct implications to the subsequent care. Wrong documentation impeaches the patient rights to have good care, and can lead to legal implications to the staff since it is a form of negligence. There is subsequent increase in the cost of care towards the patient side since he is receiving what he not supposed to receive (Zendejas, Ali, Huebner, & Farley,

Joseph Brant Essay Example | Topics and Well Written Essays - 2500 words

Joseph Brant - Essay Example Perhaps no Freemason who ever lived in America has been so condemned by some authors and praised by others as Joseph Brant, the powerful and influential Mohawk chief who sided with the British during the American Revolutionary War.Born at Cuyahoga Ohio Country on the banks of the Cuyahoga River, near present-day Akron, Ohio, during the hunting season when Mohawks travelled to the area, Brant was originally named Thayendanegea, which has possibilities of meaning two wagers (sticks) bound together for strength, or "he who places two bets." The parents of Joseph Brant were Mohawks whose home was at Canajoharie on the Mohawk River in New York. Brant, however, was born on the banks of the Ohio River in 1742 while his parents were on a hunting excursion to that region.(1) His father was Nickus (or "Nicholas") of the Wolfe family, who, although not a chief, was a Mohawk of some standing in the tribe. His mother Margaret, or Owandah, the niece of Tiaogeara, a Caughnawaga sachem, took Joseph and his older sister Mary , alsoknown as Molly, to Canajoharie, on the Mohawk River in east-central New York, where she had lived before her family moved to the Ohio River. His mother remarried on 9 September 1753 in Fort Hunter (Church of England) a widower named Brant Canagaraduncka, who was a sachem of the tribe. Thus he got the name of Brant.Sir William Johnson, the British superintendent of the northern Indians of America, who was extremely popular with the tribes under his supervision, developed a liking for Brant when he was just in his youth. During his time with the Iroquois, Johnson became particularly close to the Mohawk tribes. He was also a Mason and a former Provincial Grand Master of the New York colony. In 1759 Johnson's wife, Catherine died and he then married his Indian mistress who happened to be Brant's sister, Molly in an Indian ceremony later that year. It was due largely to Johnsons relationship with Molly that Brant received the favor and protection of Sir William and through him the British government, which set Brant on the road to promotion. Brant and a number of young Mohawks were selected by Johnson to attend Moors Charity School for Indians at Lebanon, Connecticut- the school which was later to become Dartmouth College. Here he learned to speak and write English and was introduced to Western history and literature studies. He is the only one of those chosen known to have derived any benefit from the educational process standing at that time. He left school to serve under Sir William from 1755-1759 during the French and Indian War (1754-1763). After these participatons, he became Sir William's close companion and helped him run the Indian Department which was administered by the British out of Quebec. He was also assigned the work of an interpreter for an Anglican missionary and helped translate the prayer book and Gospel of Mark into the Mohawk language, which he did in a quite orderly fashion. About 1768 he married Christine, the daughter of an Oneida chief, whom he had met in school. He then settled with her on a farm near Canajoharie which he had inherited. While here, Brant assisted in revising the Mohawk prayer book and translating the Acts of the Apostles into the Mohawk language. He also joined the Anglican Church, was a regular communicant, and evinced a great desire to bring Christianity to his people. His wife died of tuberculosis about 1771, leaving him with a son and a daughter. In 1773, he married his wife's sister, Susannah, who died a few months afterward, also of tuberculosis. In 1780, he married Catherine Adonwentishon Croghan, the daughter of the prominent American colonist, Indian agent, fur trader, and New York-Pennsylvania-Ohio landowner/speculator George Croghan and a Mohawk mother, Catharine Tekarihoga. They had seven children: Joseph, Jacob, John, Margaret, Catherine(2), Mary and Elizabeth. Through her mother, Catharine Adonwentishon was head of the Turtle

Why The US Has Higher Crime Rates Than Other Nations Case Study

Why The US Has Higher Crime Rates Than Other Nations - Case Study Example As an aspect of an individual’s personality, self-control reflects the ability to control and set up boundaries on oneself internally in response to a certain stimulus in the environment. Myers (1995) believed that behavior and actions are affected by whether people perceive the control as internal or external in which the individual is at the mercy of the outside world. Studies have made evaluative comparisons between internal and external control which showed to a great extent that internal control subjects achieve better in a social structure and act more independently in Bennassi, et al (1998). Human behavior has shown control that is often perceived as an external force that triggers feelings of depression giving out an opportunity for avoidance. However, individuals who have learned and experience self-control can easily avoid the emergence of disruptive behavior. Self-control helps a person to resist the momentary temptations of socially unacceptable behavior. Basically, through social learning man learns to exercise personal restraints through positive and negative reinforcements through normal cognitive processing. A greater degree of self-control helps a person to resist the momentary temptations of antisocial behavior in Gottfredson and Hirschi(1990:97). Further, they showed in the General Theory of Crime, that the development of criminal behavior in individuals points out that both the elements of ‘prudent and criminal behavior’ can be predicted through the evaluation and assessment of the lack of self-control alone. They argued that self-control does not necessarily require the presence of a crime but the trait itself can be changed according to the opportunities afforded and constraints affected. Although a relatively new theory in relation to criminology their theory adapts to the idea that criminal activity is gratifying and the key to understanding crime is discovering what prevents people from the errant behavior. In effect, the authors grandstand on the idea that levels of self-control may predispose criminality.

Modeling Evaluation Essay Example | Topics and Well Written Essays - 500 words

Modeling Evaluation - Essay Example , management, business, and applied psychology are often interested in multivariate relationships among some or all of the variables in a specified model. Incidentally, SEM provides a viable statistical tool for exploring all of these relationships. It should be noted, however, that SEM is largely a confirmatory tool rather than an exploratory procedure (Diomantopoulos, Riefler, & Roth, 2008). This means that SEM will most likely be used by researchers in cases when the validity of a certain model is to be established, rather than it being used to find the appropriate model. Typically, the models being investigated depict processes presumed to underlie values obtained with sample data, and these processes are assumed to result in measures of association, like correlation, among the variables in the model (Ringle, Gotz, Wetzels, & Wilson, 2009). By and large, SEM is largely a â€Å"glorified† regression procedure which, unlike ordinary regression, doesn’t assume that measurement error is zero and can simultaneously estimate parameters representing the whole model rather than just pieces of the model (Ringle, Gotz, Wetzels , & Wilson, 2009). In the model proposed by Williams, Vandenberg, & Edwards (2009), it is greatly emphasized that researchers must give due consideration into the validity of a theory embedded or implied in the proposed measurement since there are many cases when indicators could be viewed as causing rather than being caused by the latent variable measured by the indicators. A latent variable is a variable that cannot be directly observed and must be inferred from measured variables (Burnette & Williams, 2010). In many cases, researchers will not be able to detect all possible causes of error because there may be some which have neither been discussed in prior literature nor revealed by exploratory research (Grace & Bollen). Furthermore, Williams, Vandenberg and Edwards argue that some goodness-of-fit indexes, such as chi-square, are meaningless

Reflection response Assignment Example | Topics and Well Written Essays - 250 words

Reflection response - Assignment Example What about students that will be able to work in the laboratory setting, but not others? Is that fair to everyone, or the teacher? No, it is not. To expect a teacher to have multiple standards for a classroom of sometimes 25-30 students will effectively cripple the class. Classroom lectures, especially in subjects such as science, need to have continuity and flow from one point to another to help the students understand the material. One standard will help this, while multiple standards will create disruption and confusion while multiple lectures are conducted in words that students can understand and comprehend. What are the students to do while these multiple lectures are going on? While some type of work could be assigned, the confusion in the classroom will not create an ideal learning environment, and students will inevitably fall behind. Having multiple standards will not only effectively cripple the class in terms of disruption; it will spread the teacher too thin and make the teacher unable to adequately prepare the class or students. It is hard to imagine having to create more than one lesson plan for any classroom, and by having multiple standards, at least two if not more lesson plans will need to be created.

Business Plan. It's about Pet shop Essay Example | Topics and Well Written Essays - 1250 words

Business Plan. It's about Pet shop - Essay Example The company faces a threat to competitor, but its mission of employing professionally provides the company with an edge to outdo another firm in the market. The company aims to earn more revenue in training and grooming of pets as well as selling to new customers. Pet Shop is a partnership business that involves itself in pet fashion and beautification. Just like celebrities, pets have attracted an increased attraction among the citizen of the country. This gives Pet Shop a ready market for pet training, grooming and partnership in fashion shows and magazines. Pet Shop recruits experts and professional staff to improve service delivery to promote firm products in the market. The company recognizes the power of it suppliers and hold them at higher esteem to deliver on the target of the company. Pet Shop believes in happy and healthy families and thus encourages people to have one or two pet in their homes. Pet Shop aim at promoting the pet industry. The company has the strategy of training home pet as well as advocating fashions shows and partner selection to ensure the procreation of pets in their new homes. This would attract a lot of audience in the show business and guarantee a source of revenue for the company. Pet Shop prospect to partner with entrainment fashion show and magazine producers to sell it services to the public. This is a long term strategy. Therefore, because people love their cats and dog so much, Pet Shop promise to make people home a beautiful with smart pets around them. Pet Shop aim to attract more than 100 million customer in it five years in the business. This would be achieved by constant expansion of market from within the country to oversee and introduction of pets business in countries that do not practice pet ownership. The fashion industry is dominated by human and introduction of pets to fashion participant will be a game changer in the industry. This will attract celebrities to groom themselves as

Impact of Columbus Voyages on the Indigenous People Essay Example for Free

Impact of Columbus Voyages on the Indigenous People Essay The indigenous people were accustomed to sicknesses of their own but none like the ones brought by the Spanish. With the coming of these diseases many of the indigenous people died from small pox and chicken pox. Realizing this effect the diseases had on them many might have committed suicide and led up to other ways in which the indigenous people died out. After Columbus had left for the first time his men became lazy and put the indigenous people to work and as a result these people attacked but it was futile and many of them died. This was because the Spanish men were better armed with steal and metal weapons, powerful crossbows unlike the simple arrows and bows of the indigenous people. As taken from Caribbean History: Foundations Book 1 written by William Claypole and John Robottom it says ‘The Spaniards used horses for quick attacks and retreats, while the Tainos suffered dreadful casualties by rushing headlong at the enemy. In a very short time, tens of thousands were killed’. Afterwards the people were forced to pay taxes of gold and cotton or they were forced to give several weeks of free labour. The way in which the indigenous people were killed also known as genocide happened under the Spanish rule and decreased the population of these people. Indigenous people were polytheistic and their God’s were known as Zemis that they represented with wood, bone and stone carvings. Their Gods gave them good crops, sun, rain and corn. They believed deeply in these Gods and so when the Spanish tried to change their belief to that a foreign one with one God it was very difficult for them also because they were not interested in Christian learning. This made them see that there will no longer be the sun, rain and corn. Their religious practices were changed because of forced conversion to what the Spanish referred to ask Christianity. The Spanish saw the indigenous people as ‘heathens’ and wanting to please their country tried very hard to force their region on these people. Family was a big part of the indigenous society even in those where they were not a formed community like the Kalinagos who moved around and did not stay in one place. The breaking up of families made it difficult for the people to feel the togetherness of a community again. The adult males were taken away and moved around, the Kalinagos because of their war-type behavior rebelled and were killed by in the Spaniards in the wars they became part of. After so many years of fighting and trying so very hard to defend themselves, it eventually turned them into warriors which in the beginning they were not. Even if at first they were not accustomed to the fighting, suicide, killing and raids they now had to deal with these many things. Some of these indigenous people fled to the mountains and became maroon .As extracted from Karifuna/Kalinago of Dominica by Sidney Mejia ‘Indigenous people were thus being regularly displaced or exiled (to make way for plantations) to areas that were less fertile.’ They did things like destroying crops, refusing to work, poisoning the water supply and burning the food stores trying to succeed in getting back what they were before.

Congestive Heart Failure Introduction Of Patient Nursing Essay

Congestive Heart Failure Introduction Of Patient Nursing Essay This cases study was conducted on February 13th, 2012. This patient will be identified by the initials AH throughout this paper. AH is a 91-year-old Caucasian female. Her mood is as expected for her age and culture. This patient agreed to work with me during her hospital stay and continuation of follow up information after discharge. AH was admitted to the hospital on February 09th, 2012 onto the medical floor. This patient was brought into the emergency department by her son, DH, at approximately 9:00 a.m. on February 09, 2012. AH stated she had an increase of shortness of breath, weakness throughout her body, and her ankles were swollen. When asked about the history of these symptoms, AH stated these symptoms have been present since Sunday February 05, 2012. AH went into the doctors office in her hometown and was told to go into the emergency department at the hospital by the physician. On assessment at the emergency department, AH had a temperature of 96.9 degrees Fahrenheit, a pulse of 130 beats per minutes, respirations of 20 breaths per minute, blood pressure of 192 systolic over 105 diastolic, and a pain level of 0 out of 10 on the pain rating scale. Assessment findings were crackles, bilaterally with auscultation, a non-productive cough occasionally, irregular heart rate, 3+ pitting edema bilaterally in lower extremities from the knee down and in feet. This patient had a delayed capillary refill and neck vein distension. AH also had palpable pulses with upper extremity pulses being strong and lower extremity pulses being weak. This patient was admitted with congestive heart failure and atrial flutter with rapid ventricular response. This patient has a history of hypertension, arthritis, hard of hearing, occasional urinary tract inf ections and had a myocardial infarction in 1990. AH had two previous surgical procedures in her life. She has had a left hip replacement in 2006 and a right hip replacement in 2007. AH denies any significant family health history. She also denies any current use or history of alcohol consumption, tobacco use, or drug use. She is not on any supplemental oxygen at home. AH was able to state name, dose, and reason for home medications. These medications are Bumex water pill 1 MG orally taken daily, Clonidine blood pressure pill 0.1 MG orally taken three times a day, Metoprolol blood pressure pill 50MG orally taken daily, and Nitroglycerin for heart 2.5MG orally taken two times a day. I was able to do a total head to toe assessment on February 13, 2012. AH is 182.90 pounds, 60.00 inches tall, and has a body mass index of 35.72. AH is categorized as obese with this body mass index result. This patient is alert and oriented to person, place, and time. This patients pupils are equal, responsive, and reacts to light upon inspection. AH does have slight pitosis of the right upper eyelid. This patient does wear eyeglasses to read. Her total Glasgow Coma Scale is rated at a 15 out of 15. This is a perfect score and shows no impairments. This patient communicates verbally with no problems. AH has full movement in all four extremities and has intact circulation, movement, and sensation. When asked about history of falls, AH stated she had no current or past falls. Her skin is pink, warm, and dry without diaphoresis but has slight purplish discoloration bilaterally on shins from knee to ankle. When assessing AH respiratory status, she stated that she was not experiencing an y distress or shortness of breath currently but does experience this with exertion. AH is not on any supplemental oxygen. Her oxygen saturation was at 94% on room air. Upon auscultation this patients lungs were clear bilaterally in upper lobes and diminished bilaterally in lower lobes. Her respirations were at 16 breaths per minute. Her chest configuration is symmetrical. I did observe a weak non-productive cough occasionally during this assessment. During the cardiovascular assessment, apical pulse was 84 and her radial pulse was 80. This showed a pulse deficit of 4 beats per minute, which could be due to the irregular heartbeat (atrial flutter) with the rapid ventricular response. Patient was on telemetry to monitor for abnormalities during admission. S1 and S2 were heart upon auscultation. AH had a blood pressure of 167 systolic over 82 diastolic on her right upper extremity. AH did have distended neck veins upon inspection, which is a sign of congestive heart failure. AH denied any chest pain. This patient does not have any implanted cardiac defibrillator or pacemaker. This patients abdomen was soft and non-tender with bowel sounds active in all four quadrants. She is on a low sodium diet and states that she does follow the diet restrictions but when asked about exact amount of allowed sodium intake patient did not know. During her hospital stay AH was on a fluid restriction of 1.5 liters per 24 hours. Patient was able to adhere to fluid restriction but states she is on no fluid restriction at home. AH is continent of stool and urine but had Foley catheter in place per physician orders. AH is full weight bearing and has a steady gait but does use a walker for an assistive device while at the hospital. AH states she uses a wheelchair at home. AH has active range of motion and shows no limitations or discomfort within normal limits. AH was under no precautions or isolation. She had five different medications that I administered to her during her admission to the hospital that ranged from antibiotics, hypertension medications, to diuretics. These will be discussed individually in the following systems breakdowns. When asked about cancer screenings, AH denied any annual appointments. AH stated that she was not worried about this currently. AH also does not obtain influenza or pneumococcal vaccines annually and her last tetanus vaccine was unknown. From observation, this patients health promotion is low and patient may need education on importance to her health. When assessing this patients home life, AH stated she has never had any physical or emotional abuse. AH lives at home with her son DH. Her husband passed away several years ago so she arranged for her son to come live with her. DH provides transportation and assistance with activities of daily living for AH. She has a loving relationship with her son and he assists her with medical decisions. She states she is not afraid of her living situation. AH complied with medical regimen and asked questions when she was not sure of the situation. When asked about the history of her congestive heart failure and length of time she has been diagnose d, AH did not understand that she had congestive heart failure and did not know how long she has had this condition. She stated she would speak with her new physician. She will be set up with a new primary physician since she does not currently have one. With this information, this indicates an need for additional information about primary condition due to deficient knowledge stated by patient. Pathophysiology of Congestive Heart Failure The heart, blood vessels, and blood are components that make up the cardiovascular system. The pumping action of the heart consists of contraction and relaxation of the myocardial (muscle) layer of the heart. Each contraction and relaxation that occurs consists of one cardiac cycle. During diastole (relaxation), the ventricles fill with blood. Systole (ventricular contraction) then occurs, which propels the blood out of the ventricles and into the circulation. Cardiac performance can be calculated by measuring the cardiac output. Cardiac output is the amount of blood moving through either systemic or the pulmonary circuit per minute. (Huether McCance, 2008) Cardiac output is calculated by multiplying stroke volume (volume of blood ejected per beat during systole) and heart rate. The amount of blood a ventricle ejects during the cardiac cycle is called ejection fraction. Ejection fraction is calculated by stroke volume divided by end-diastolic volume (blood left in the blood after di astole). The normal ejection fraction is from 50%-70%. A decrease of ejection fraction is a hallmark sign of ventricular fraction, such as left-sided heart failure. The factors that determine cardiac output are preload, afterload, contractility, and heart rate. Preload is the volume and associated pressure generated in the ventricle at the end of diastole (ventricular end-diastolic volume). Preload is determined by the amount of venous return to the ventricle and the blood left in the ventricle after systole (end-systolic volume). Afterload is the resistance the heart has to overcome to eject blood from the left ventricle. Heart failure is a term for the inability of the heart to work effectively as a pump. It results from different acute and chronic cardiovascular problems. The major types of heart failure are left-sided heart failure, right-sided heart failure, and high-output heart failure. The focus of this case study will be on left sided heart failure. Most heart failure starts out with failure of the left ventricle and progresses to both ventricles failing. Typical causes of left-sided heart failure are hypertension, coronary artery, and valvular disease. Decreased tissue perfusion from poor cardiac output and pulmonary congestion indicate left ventricular failure. Left-sided heart failure is also known as congestive heart failure; however not all cases of left ventricular failure involve fluid accumulation. Left-sided heart failure can be further broke down to systolic heart failure and diastolic heart failure. (Ignatavicius Workman, 2010) Systolic heart failure happens when the heart is unable to contract forcefully enough during systole to eject sufficient amounts of blood into the circulation. Preload increases with decreased contractility, and afterload increases as a result of increased peripheral resistance in the vascular spaces (hypertension). The percentage of blood ejected from the heart during systole (ejection fraction) drops from the normal range (50%-70%) down to 40%. As this percentage decreases, tissue perfusion decreases and blood backs up into the pulmonary vessels. This creates symptoms of systemic and pulmonary congestion. Diastolic heart failure occurs when the left ventricle cannot relax enough during the rest period. When the ventricle cannot relax enough, stiffening of the ventricle occurs and prevents the ventricle from filling up with sufficient blood to ensure adequate cardiac output. This ventricle becomes less compliant because more pressure is needed to move the same amount of volume compa red to a healthy heart. (Ignatavicius Workman, 2010) When cardiac output is unable to meet the demands of the body, other areas of the body start to increase their workload to improve cardiac output. Theses mechanisms start off helping cardiac output increase but eventually have a damaging effect on the function of cardiac pumping. The compensatory mechanisms of heart failure are stimulation of the sympathetic nervous system, activation of the renin-angiotension system, release of pro-inflammatory cytokines, release of natriuretic peptides, release of vasopressin, and myocardial hypertrophy. (Ignatavicius Workman, 2010) These compensatory mechanisms will be discussed further in the appropriate body systems throughout this case study. There are many presenting signs and symptoms of heart failure that a patient may have. Signs and symptoms of left-sided heart failure are restlessness, confusion, orthopnea, tachycardia, dyspnea with exertion, fatigue, cyanosis, cough, crackles, wheezes, blood-tinged sputum, and tachypnea. AH has several of these problems. She has tachycardia, dyspnea with exertion, fatigue, orthopnea, occasional cough, tachypnea, and crackles heard with auscultation. These problems make AHs activities of daily living hard to perform at times. She does not use any supplemental oxygen during any of these times. AH is also showing signs and symptoms of right-sided heart failure that could indicate that her condition is progressing. These symptoms are distended jugular veins, and dependent edema. These symptoms of right-sided heart failure can be due to her history of a myocardial infarction, which could have caused the right ventricle to try and compensate for the increase in pulmonary circulation. Thi s leads to the right ventricle to dilate and begin to fail. This is the cause of the distended jugular veins and edema because the systemic venous circulation increases with the compensation of the right ventricle. Treatment of these symptoms is managed with the treatment of left-sided heart failure. (Huether McCance, 2008) There are several risk factors that put a patient at risk for heart failure. Common risk factors that put a patient at risk for heart failure are hypertension, coronary artery disease, cardiomyopathy, substance abuse with alcohol and tobacco use, dysrhythmias, cardiac infections and inflammations, diabetes mellitus, family history, obesity, and conditions such as hyperthyroidism. (Ignatavicius Workman, 2010) AH has several of these risk factors. She has a history of hypertension, obesity, atrial flutter (dysrhythmia), and past myocardial infarction. All of these have a negative affect on the cardiovascular system and lead to the worsening this patients heart failure. Lifestyle modifications can be made to decrease how some of these risk factors affect this patient. Dietary changes such as watching weight, low sodium, and balanced meals could reduce this patients obesity and hypertension. Also, adhering to medication regimen assists with controlling hypertension and removing retained water from the body. Chest x-rays can be helpful in the diagnosis of left ventricular failure. The problem with chest x-rays is that it may lag behind the clinical findings as much as 24 hours. You may see that the heart is enlarged (cardiomegaly) which can be due to hypertrophy and dilation. AH had a chest x-ray done on February 08, 2012. The reason this was done was because of dyspnea. Results obtained from physician were trachea midline, mild prominence of interstitial markings in bilateral lung fields without lobar consolidation, basilar atelectasis, elevated left hemidiaphragm, no evidence of pneumothorax or pleural effusion, mild cardiomegaly, ectatic aorta with vascular calcification and degenerative changes involving shoulder joints. Echocardiograms are considered the best tool in the diagnosis of heart failure. You can see changes in the valves, fluid accumulation in the pericardial space (pericardial effusion), chamber enlargement, and ventricular hypertrophy. This test can also determine eject ion fraction, which shows how bad the ventricular hypertrophy is decreasing the amount of blood ejected from that ventricle. An electrocardiogram may show ventricular hypertrophy, dysrhythmias such as atrial flutter with AH, and any degree of myocardial injury but is not helpful in determining the presence or extent of heart failure. (Ignatavicius Workman, 2010). This test would be helpful for this patient due to the fact of having a dysrhythmia and also have a past myocardial infarction. Laboratory assessments can also be helpful in diagnosis of heart failure. Electrolyte imbalances may occur from heart failure or because of side effects of medications, especially diuretics such as Bumex with AH. Regular assessments of sodium, potassium, magnesium, calcium, and chloride, are obtained. Any impairment of renal function resulting from inadequate perfusion causes the patients blood urea nitrogen and serum creatinine to be elevated and a decrease in creatinine clearance levels. A urinalysis can show if there is an increased amount of protein present in the urine and an elevated specific gravity due to the kidneys not adequately working. Hemoglobin and Hematocrit levels should be obtained to check to see if the heart failure is from anemia, which is a low level of red blood cells. This can be caused from the kidneys not creating enough erythropoietin, which regulates red blood cell production. B-Type natriuretic peptide (BNP) is used for diagnosing heart failure in patient s with dyspnea. An increase in BNP helps determine whether it is dyspnea from heart failure or lung dysfunction. Patients with atrial dysrhythmias and renal disease may also have elevated BNP levels. (Ignatavicius Workman, 2010) AH does have an atrial dysrhythmia (atrial flutter), which could cause an elevated BNP level even without the heart failure. Arterial blood gases could show if the patient is hypoxic due to the low oxygen level from fluid filled alveoli. Respiratory alkalosis could occur because of hyperventilation, respiratory acidosis could occur because of the carbon dioxide retention, and metabolic acidosis could be present from accumulation of lactic acid. (Ignatavicius Workman, 2010). AH did not have arterial blood gas values drawn to look at any abnormalities. TEST RANGE DATE: 02-08-12 DATE: 02-11-12 DATE: 02-13-12 WBC 5,000-10,000 mm3 8.89 mm3 10.00 mm3 RBC 4.2-6.1 X10 / g 4.70 5.11 HGB 11.5-17.5 g/dl 13.8 g/dl 14.8 g/dl HCT 40-52% 43.7% 46.8 % PLATELETS 150,000-400,000 mm3 194,000 mm3 207,000 mm3 NEUTROPHILS 55-70% 78.0% 78.8 % LYMPHOCYTES 20-40% 10.3% 9.5 % MONOCYTES 2-8% 8.7% 9.2 % EOSINOPHILS 1-4% 1.7% 1.5 % BASOPHILS 0.5-1.0% 1.3% 1.0 % SODIUM 135-145 mEq/L 142 mEq/L 138 mEq/L 13 mEq/L CHLORIDE 98-106 mEq/L 105 mEq/L 98 mEq/L 93 mEq/L POTASSIUM 3.5-5.0 mEq/L 5.5 mEq/L 5.0 mEq/L 4.2 mEq/L CO2 24-30 mEq/L 28 mEq/L 28 mEq/L 35 mEq/L MAGNESIUM 1.3-2.1 mEq/L 1.9 mEq/L CALCIUM 9.0-10.5 mg/dl 7.7 mg/dl 7.8 mg/dl 7.3 mg/dl BUN 10-20 mg/dl 45 mg/dl 68 mg/dl 68 mg/dl CREATININE 0.5-1.2 mg/dl 1.29 mg/dl 1.58 mg/dl 1.52 mg/dl GFR 39 37 39 GLUCOSE 70-110 mg/dl 108 mg/dl AST 0-35 U/L 47 U/L ALT 4-36 IU/L 112 IU/L BNP 952 361 TROPONIN I 0.10 0.07 Treatments for heart failure are a combination of pharmacologic and non-pharmacologic therapies. Treatment often focuses on a combination of afterload-reduction with angiotension-converting-enzyme (ACE) inhibitors, reduction of catecholamine surges with beta blockers, and preload reduction with diuretics. ACE inhibitors reduce the production of angiotension II, which is a potent vasoconstrictor, from angiotension I. This will allow the patients blood pressure to lower to a normal range by vasodilation and also prevents ventricular remodeling (alteration in the structure and function of the heart). These medications are recommended for all patients with heart failure with lowered systolic function. With these medications you need to monitor for adverse effects such as dry hacking cough, hypotension, and renal dysfunction. AH was given Lisinopril 10MG tab QD during her hospital admission. Beta blockers protect the heart from the harmful effects of norepinephrine and epinephrine which a re circulating neurohormones released as a compensatory mechanism. This is aimed to reverse ventricular remodeling. Beta blockers help reduce mortality when combined with ACE inhibitors. This combination is referred to as the cornerstone of heart failure treatment. AH was given Lopressor 100MG tab BID to inhibit beta 2 adrenorecpetors of bronchial and vascular smooth muscle. (Jones Bartlett, 2010). This medication helps lower blood pressure and relieve patient of symptoms of heart failure. Diuretics are a key aspect in the relief of dyspnea and signs of sodium and water retention. This helps reduce blood pressure by removing extra fluid in the circulation. Also, putting the patient on sodium restriction decreases the resistance of diuretics. These medications can also be the first line of treatment for older adults with heart failure and fluid overload. AH was administered Bumex 1MG tab BID. This is a loop diuretic, which means it inhibits reabsorption of sodium and chloride in the ascending Loop of Henle and enhances potassium excretion. (Jones Bartlett, 2010) With this medication you must monitor the patients labs to prevent hypokalemia. Another treatment option for heart failure is cardiac glycosides. These drugs increase intracellular calcium, which increases contraction of the heart. Their function results from an increased cardiac output by increasing the force of contraction of the heart. (Jones Bartlett, 2010). Digoxin was the cardiac glycoside administered to AH during her hospital admission. AH received 125MCG tab QD. Potential benefits of this medication are increased contractility, reduced heart rate, slowing of conduction through the atrioventricular node and inhibition of sympathetic activity while enhancing parasympathetic activity. (Ignatavicius Workman, 2010). Monitoring potassium levels is very important for this medication due to lower levels causing patients to be more sensitive to digoxin, which can cause digitalis toxicity. These sign s and symptoms are also vague and nonspecific and include; anorexia, fatigue, changes in mental status and dysrhythmias. Watch for a loss of the P wave on an electrocardiogram. Also, you must monitor apical pulse and heart rhythm on these patients. You must make sure the heart rate is above 60 beats per minute. Any drug that increases the workload of the heart will also increase its oxygen demand. Patients should be monitored for chest pain while taking digoxin. Non-pharmacological interventions for heart failure are ventilation assistance, energy management, and nutrition therapy. Ventilation assistance is an important aspect of treatment for heart failure patients. This allows the patient to have adequate oxygen and carbon dioxide exchange in the lungs. Depending on the patients oxygen saturation and dyspnea, they may need supplemental oxygen prescribed by the physician. Positioning the patient in a high Fowlers position, and keeping the head of the bed elevated over 45 degrees will minimize respiratory efforts. AH did not receive supplemental oxygen, but maintained adequate ventilation by sitting in a bed side chair most of the time during her admission. She was unable to sleep in the hospital bed due to complaints of orthopnea so she also needed to sleep in the chair. (Ignatavicius Workman, 2010) Energy management will help prevent fatigue and perform activities of daily living to the best of their ability. Steps to take to promote ener gy management is monitor patient response to activity, determine patients physical limitations, encourage alternate rest and activity periods, arrange physical activities to reduce competition for oxygen supply to vital body functions, encourage physical activity, monitor patients oxygen response, and teach patient techniques of self-care that will minimize oxygen consumption. (Ignatavicius Workman, 2010) AH was able to ambulate to the bathroom when needed, but was unable to ambulate larger distances. She maintained adequate oxygenation with adequate rest periods when she became short of breath. AH is able to identify when these rest periods need to be taken on her own. Nutrition therapy is also a key aspect in the treatment of heart failure. This treatment targets sodium reduction and water retention. Physicians may prescribe sodium restrictions to decrease fluid retention. Since sodium follows water, a decrease in sodium allows for a decrease in retained water. AH was on a sodium restricted diet but was unable to state the exact amount of allowed daily sodium. All she could state was that she was not allowed to add extra salt to meals. Some patients are also placed on fluid restrictions. This allows for the body to excrete retained fluid in the body without having work harder with additional fluid intake. The restriction depends on the patient and the extent of the heart failure. AH was put on fluid restrictions by her physician. She was allowed 1.5 liters of fluid per 24 hours. AH was able to comply with this restriction. Assistive personnel need to be accurate in measuring intake and output for these patients. Weighing these patients daily is a key factor for heart failure. This allows seeing if the patient is retaining extra fluid which could cause congestion and result in worsened heart failure. 1 kilogram of weight gain or loss equals 1 liter of retained or lost fluid. The same scale should be used everyday at the same time of day (morning) wearing close to the same amount of clothing for the most accurate assessment of weight. (Ignatavicius Workman, 2010) Cardiovascular The heart, blood vessels, and blood all make up the cardiovascular system. The hearts pumps the blood through a network of blood vessels and delivers oxygen, carbon dioxide, and nutrients to the cells and tissues of the body. This circulatory system also removes waste products of cellular metabolism. (Huether McCance, 2008). The blood is carried away from the heart by arteries that branch into capillaries and provide the body with all the nutrients needed to properly function. Veins carry the blood from the capillaries throughout the body back to the heart where the system starts the process over. Since AH has congestive heart failure (as described above), hypertension, atrial flutter, and previous myocardial infarction, her cardiovascular system is greatly affected. One compensatory mechanism that occurs in the cardiovascular system due to congestive heart failure is myocardial hypertrophy. This is enlargement of the myocardium and can be with or without dilation of the chamber. The heart walls thicken to provide more muscle mass. This results in more forceful contractions. This further increases cardiac output. Often a hypertrophied heart is slightly oxygen deprived. All the compensatory mechanisms contribute to an increase in consumption of myocardial oxygen. When the demand for oxygen increases, and the reserve of the myocardium has been exhausted, manifestations of heart failure develop. AH has a history of hypertension. Hypertension is a consistent elevation of systemic arterial blood pressure. It is defined as a sustained systolic blood pressure of 140 mm Hg or greater systolic pressure or a diastolic pressure of 90 mm Hg or greater. (Huether McCance, 2008) There are four different classifications of hypertension. These are normal, prehypertension, stage 1 hypertension, and stage 2 hypertension. AH is categorized in stage 2 hypertension with her systolic blood pressure ranging around 167 mm Hg. This stage of hypertension puts her at risk for damage to target organs such as her brain, kidneys, and heart. Since systolic hypertension is the most significant factor causing target organ damage, this puts AH at an even higher risk. AH also has an elevated diastolic blood pressure ranging around 82 mm Hg. She would be categorized as prehypertension with this value. When a patient has hypertension both by systolic and diastolic measurements, they are diagnosed with primar y hypertension. A specific cause for primary hypertension has not been identified but it is found that a combination of environmental and genetic factors can be the cause of development. Factors associated with primary hypertension are family history, advancing age, gender (more common in women after age 55), black race, high dietary sodium intake, glucose intolerance, cigarette smoking, obesity, heavy alcohol consumption, and low dietary intake of potassium, calcium, and magnesium. (Huether McCance, 2008) AH has several of these factors which are a family history of hypertension, advancing age, female gender, obesity, and poor nutritional status. Many of these factors are also risk factors for other cardiovascular disorders. With AH, the history of myocardial infarction and congestive heart failure all accumulate to poor cardiovascular effects. Pathophysiologic mechanisms mediate these effects that include; the sympathetic nervous system, the renin-angiotension aldosterone system, and natriuretic peptides. The systemic arterial pressure is made up of cardiac output and total peripheral vascular resistance. Total peripheral vascular resistance is the resistance of blood flow in systemic blood vessels. Cardiac output is determined by multiplying stroke volume and heart rate. Stroke volume is the amount of blood ejected by the ventricle with each beat of the heart. Control of peripheral vascular resistance (dilation or constriction) is controlled by the autonomic nervous system (sympathetic and parasympathetic) and circulating hormones (epinephrine and norepinephrine). Any factor that affects peripheral vascular resistance, heart rate, or stroke volume affects systemic arterial pressure, which affects the patients blood pressure. If all increase, blood pressure will increase. If all decrease, blood pressure will decrease. Four control systems play a major role in maintaining blood pressure; the arterial baroreceptor system, regulation of body fluid volume, the renin-angiotension aldosterone system and vascular autoregulation. The arterial baroreceptors monitor the arterial pressure and counteract a rise in arterial pressure by mediated cardiac slowing and vasodilation. (Ignatavicius Workman, 2010) Changes in fluid volume and renin-angiotension aldosterone system will be discussed further in the renal system. Patients with hypertension are often asymptomatic, however patients may have headaches, dizziness, fainting, facial flushing. AH had no complaints of any of these symptoms, but I did observe facial flushing. AH stated that she has had blood pressure issues for quite some time now. AH is on several medications to help assist the body in lowering her blood pressure. She is taking Lopressor 100 MG tab BID (beta blocker), Digoxin 125 MCG tab QD (cardiac glycoside), Lisinopril 10 MG tab QD (angiotension converting enzyme inhibitor) and also Bumex (loop diuretic). All of these medication help lower her blood pressure which will decrease the workload of the heart which assists in compensating in the effects of her congestive heart failure. Atrial flutter is a rapid depolarization occurring at a rate of 250 to 350 times per minute. This rapid depolarization is caused from the electrical current circulating in a small circle within the atria instead of moving from one end to the other. This current travels in a circle because conduction is slowed due to heart damage and the myocardial cells are unable to activate. (Huether McCance, 2008). This is considered a supraventricular tachycardia due to the fact that it is above the ventricle. The atrioventricular node (between the right atrium and right ventricle) in the heart blocks the number of impulses that reach the ventricles as a protective mechanism. (Ignatavicius Workman, 2010). Atrial flutter has many causes but two causes that are related to AH are ischemic heart disease (myocardial infarction), and heart failure. Symptoms are palpitations, weakness, fatigue, shortness of breath, nervousness, anxiety, syncope, angina, and signs of heart failure. AH has several of th ese symptoms but they also could be due to her heart failure. The patient with a normal ventricular rate is usually asymptomatic. Due to her left ventricle conducting at a slower rate, she is at risk for having these symptoms. With these

The structure of a commercial aircraft

The structure of a commercial aircraft Introduction This is assignment is based on structure of an aircraft. The structure of an aircraft has been explained briefly in this assignment. I am going to start my assignment with typical aircraft diagram. This assignment is particular based on commercial aircraft, emphasising various major structural components. The major structural components refer to the primary structure of an aircraft. If the primary structure fails the aircraft wont be capable of flying anymore. It can lead to complete structural damage. I am going to do an intensive research on load transfer structure using Aircraft structure from engineering book, and I am going to explain about the maximum load case which will cover N-V diagram as well Structure Classification: For the purpose of assessing damage and the type of repair to be carried out on the aircraft the structure is divided into three main categories Primary Structure Secondary Structure Tertiary Structure Primary Structure: Primary structure includes all the portions of the aircraft, the failure of which during flight or on the ground would cause catastrophic structural collapse and loss of control. Examples of Primary Structure include: Wings Fuselage Tail Landing Gear Wings Wing is a surface providing the lift to the aircraft. They are attached to fuselage on each side .They are usually in aerofoil shape. They can be attached at the top, middle, or lower portion of the fuselage depending on the required performance for the particular airplane. The number of wings can also vary. The wings consist of two essential parts. The internal wing structure which consist of spars, ribs, stringers and the external wing, which is the skin. C:UsersRIZWAN ULLAHPictureswing-components.gif Fig 2: Components of the wing (2) In a fixed-wing aircraft, the spar is the main structural member of the wing, located at right angle to the fuselage running spanwise. They run from the base of the wing toward the tip and are usually attached to the fuselage by the wing fittings. It carries flight loads and the weight of the wing. Sometimes more than one spar may be located on a wing or there might be none at all (3) In the framework of a wing, ribs are the crosspieces running from the leading edge to the trailing edge of the wing. The ribs give the wings its contour and shape and transmit the load from the skin to the spars. Ribs are also used in ailerons, elevators, fins and stabilizer (4) Stiffener which assists sheet materials to carry loads along their length. With integral construction they are machined or etched out of the skin panel Fuselage The body of the airplane, which carries the crew and payload, such as passengers or cargo, is called the fuselage. It looks like a tube which holds most of the aircraft together. The other structural units are directly or indirectly attached to it. It also provides stability and also control pitch and yaw movement of the aircraft C:UsersRIZWAN ULLAHPictureshttpimages.google.co.ukimgresimgurl=httpwww.grc.nasa.govWWWK-12airplaneImagesfuselage.gifimgrefurl=httpwww.grc.nasa.govWWWK-12airplanefuselage.htmlusg=__JKzqTJ1GPBfQcNIPubnvd2PTbqk=h=533w=710sz=22hl=enstart=1sig2=YzE.jpg (5) Fig 3: Fuselage Types of Structure: There are two different types of structure: Monocoque type Semi Monocoque type C:UsersRIZWAN ULLAHPicturesUntitled.jpg (6) Fig 4: Warren truss of welded tubular steel Monocoque Construction: This is further classified into the true Monocoque construction and the more common semi Monocoque construction. The true Monocoque construction uses formers, frames assemblies, and bulk heads to give shape to the fuselage, but the skin carries the primary stresses. Since the bracing members are present, the skin must be strong enough to keep the fuselage rigid. Thus, the biggest problem involved in Monocoque construction is maintaining enough strength while keeping the weight within allowable limits. C:UsersRIZWAN ULLAHPictureshttpairplanegroundschools.comAircraft-StructureFigure1-3.jpg.jpg (7) Fig5: Monocoque Construction Semi Monocoque Construction The semi monocoque fuselage is constructed primarily of the alloys of aluminium and magnesium, although steel and titanium are found in areas of high temperatures. C:UsersRIZWAN ULLAHPicturessemimonocoquefuselagedesign1.jpg (8) Fig6: Semi Monocoque Construction The principal structural parts of the fuselage are longerons, formers, stringers and bulkheads Longerons are main structural member of a fuselage or nacelle. Longerons are a thin strip of metal to which the skin of the aircraft is fastened. Longerons are attached to formers in the case of fuselage (9) The vertical structural members are referred to as bulk heads, frames and formers. The heaviest of these vertical members are located at intervals to carry concentrated loads and at points where fittings are used to attach other units, such as the wings, power plants, and stabilizers Tail The stabilizing surfaces at the rear of the airplane are the horizontal and vertical tails. These major components are often divided into smaller elements. The forward, usually fixed, part of horizontal tail is the horizontal stabilizer. Attached to it is a movable control surface called elevator. Changing the elevator deflection changes the lift on the horizontal tail and thereby controls the angle of attack and lift of the wing. Similarly, the vertical tail is divided into the fixed vertical stabilizer or fin and the rudder. The main role of horizontal stabilizer is to provide longitudinal stability about lateral axis. It refers to motion in pitch; thereby it controls the angle of attack. The main role of the vertical stabilizer is to provide directional stability about the normal axis. It controls the yawing motion of an aircraft. (10) Fig7: Empennage Load Transfer Structure The basic function of an aircrafts structure are to transmit and resist the loads applied on aircraft so the structure can provide aerodynamic shape and protect the aircraft from environmental conditions encountered in flight. The two classes of loads may be further divided into surface forces which act upon the surface of the structure and body forces which act over the volume of the structure and are produced by gravitational and inertial effects. Basically all air loads are the resultant of the pressure distribution over the surfaces of the skin produced by steady flight, manoeuvre or gust conditions. Generally, these resultant cause direct loads, bending, shear and torsion in all parts of the structure. First, we shall consider wing sections, while performing the same function can differ widely in their structural complexity. The shape of the cross section is governed by aerodynamic considerations and clearly must be maintained for all combinations of load. They also act with the skin in resisting the distributed aerodynamics pressure loads; they distribute concentrated loads into the structure and redistribute stress around discontinuities, such as undercarriage wells, inspection panels and fuel tanks, in the wing surface. Ribs increase the column buckling stress of the longitudinal stiffeners by providing end restraint and establishing their column length; in a similar manner they increase the plate buckling stress of the skin panels. In the outer portions of the wing, where the cross section may be relatively small if the wing is tapered and the loads are light, ribs act primarily as formers for the aerofoil shape. Fuselages, while of different shapes to the aerodynamics surfaces, comprise members which perform similar functions to their counterparts in the wings and the tailplane. Aerodynamics forces on the fuselage skin are relatively low; on the other hand, the fuselage supports large concentrated loads such as wing reactions, tailplane reactions, undercarriage reactions and it carries payloads of varying size and weight, which may cause large inertia forces. (11) Maximum Stress Load case Many forces and structural stresses act on an aircraft. When it is static, the force of gravity produces weight, which is supported by the landing gear. During flight manoeuvre causes acceleration or deceleration which increases forces and stresses on wings and fuselage. V-n Diagram (15) C:UsersRIZWAN ULLAHPicturesimage2.gif Fig 8: Manoeuvre Diagram This diagram illustrates the variation in load factor with airspeed for maneuvers. At low speeds the maximum load factor is constrained by aircraft maximum CL. At higher speeds the maneuver load factor may be restricted. The maximum manoeuvre load factor is usually +2.5 . If the airplane weighs less than 50,000 lbs., however, the load factor must be given by: n= 2.1 + 24,000 / (W+10,000) n need not be greater than 3.8. This is the required manoeuvre load factor at all speeds up to Vc, unless the maximum achievable load factor is limited by stall. The structural stresses to which the aircraft is subjected to its maximum: Tension Compression Torsion Shear Bending Tension It is defined as pull, in level flight, aircraft engine and propeller pulls the aircraft forward while fuselage and tail resist that movement because of the airflow around them. Airframe is stretched as a result. Elevator control cable is in additional tension when the pilot moves the control column Compression Compression is the resistance to crushing. Aircraft wings are subjected to compression stresses, on the ground aircraft landing gear struts are under compression stress C:UsersRIZWAN ULLAHPicturesaaaa.jpg (12) Fig 9: Compression and tension stress Torsion It results from a twisting force. It is produced in an engine crankshaft while the engine is running. The airframe is also subjected to stresses during turns. C:UsersRIZWAN ULLAHPicturesUntitled.jpg (13) Fig 10: Torsional stress Shear Shear stress is the outcome of sliding one part over the other in opposite directions. The rivets and bolts experience shear stresses. Bending Bending is a combination of tension and compression. The wing spars of an aircraft in flight are subject to bending stresses C:UsersRIZWAN ULLAHPictureshttpwww.aerospaceweb.orgquestionperformanceq0146.shtml.gif (14) Fig 11: Banking angle When the aircraft is taking a sharp turn most of the forces acting on the aircraft are its at maximum, because there are forces that tend to keep the aircraft in its original path.