Roots of conflic, viol and peace Essay Example | Topics and Well Written Essays - 1000 words

Roots of conflic, viol and peace - Essay Example In the effort to bridge this gap, peace paradigms such as power politics and world order were developed. The power politics paradigm, which is dominant in matters of international relations, stipulates that there is an absence of universally acceptable values that would serve all international actors. Power politics in characterized the use of threats by one nation to the other, be it military, political and/or economic (Wight, Bull and Holbraad, 2002). It is as a result of the absence of prevailing international government that renders international politics unpredictable and volatile, with nations perpetually changing alliances. The end result is an exposure to violence, insecurity and power imbalance. According to the power politics peace paradigm, it is imperative for states to engage in the implementation of policies that would effectively serve their national objectives construed as the acquisition of military strength and material power with the aim of deterring and compelling other nations. A nation that is known to possess material and military power is less likely to be expos ed though the acquisition of such rises serious moral and ethical issues. This means that states have no alternative but to attempt to steer away from international humanistic values that are pegged on the trust and good will of nations. The lack of a common and unified moral standard that can be used as the guiding point for international cooperation means that states are left with no alternative but to strive and compete against each other in the quest to attain the perceived security providers (Gandhi Marg Magazine, 2002). The basic idea, therefore behind power politics is that for peace to prevail, people must be prepared for war. The implicit being that the human competitive aspect predisposes the world to violence and it is through the forceful implementation of order, peace is attained. While power politics is not entirely indifferent to issues such as environmental degradation and poverty, it has been criticized for advocating for a moral minimalism approach, meaning that the world has been condemned to a self help attitude, with the stronger nations overpowering less empowered nations (Wight, Bull and Holbraad, 2002). On the hand, the world order paradigm stipulates that peace can be attained through the power of law. It calls for the development of sustainable cooperation among states, inter governmental organization and non governmental organizations. The proponents of world order consider the power politics approach as a recipe of inevitable disorder. They future insist that human have both the potential to be selfish and otherwise and if they so choose, human can cooperate for the sake of the greater good. According to the proponents of the world order, international cooperation is critical in the decentralization state centered international relations models that have completely failed to secure the general interests of human beings. The fact is the world is basically a global village due to immense technological advancements. Issues such as peace, poverty, disease, human rights violations, environmental degradation, disease and weapons of mass destruction, are a major concern to people across the divide. It is for this reason that the world order stresses the on the possibility of humans to choose to cooperate. It also

Somalia Essay Example | Topics and Well Written Essays - 2000 words

Somalia - Essay Example In our present age, Somalia has always been the epitome of poverty. Pictures of toothpick-thin Somali children have flooded the magazines all over the world, with drooping eyes seemingly begging for our help. Until now, their state conditions had barely changed. Almost 15 years after Somalia fell apart in 1991 in spate of clan-based rebellions against the genocidal, 22-year dictatorship of President Mohammed Siad Barre, the fear and the loathing in this country still exists. Since 1991, there have been fourteen efforts at national reconciliation; to date, none has been successful. Various groupings of Somali factions have sought to control the national territory (or portions thereof) and have fought small wars with one another. Dahir Riyale Kahin was elected President of the self-declared "Republic of Somaliland," which is made up of the former northwest provinces of the Somali republic, in presidential elections deemed free and fair by international observers in May 2003. In 1998, t he area of Puntland in the northeast declared itself autonomous (although not independent) as the "State of Puntland" with its capital at Garowe. Puntland declared it would remain autonomous until a federated Somalia state was established (US Department of State, 2005). As we all know, the terrible famine of 1993 in the south was entirely induced by civil war. A US- and UN-led humanitarian intervention failed to understand Somali complexities, was humiliated, and when it left in 1995 had only instigated more conflicts to arise.

Analysis of Music Instruments in Movies Assignment

Analysis of Music Instruments in Movies - Assignment Example A musical score is a written form of a musical composition. Music has become one thing that people cannot do without due to its numerous advantages. Some of these include: it brings back memories, improves your concentration over time, it gives a soothing ability and some music expands our intellectual ability through the message. To Kill a Mocking Bird's score is one of the superlative scores I have ever encountered. The film based on Harper Lee's book titled by the same name. It is about a young lass Scout, and her elder brother Jem, and their feeble friend, Dill. Scout's father, Atticus (Gregory Peck) takes a case to defend a black man named Tom Robinson. He is accused of raping a white woman. A skillfully edited opening is displaying wonderful shooting and a beautiful score. Its high rating up to date bases on its affecting nature. To Kill a Mocking Bird is one of the greatest film ever, but one thing that makes me watch this movie time and time again is its exemplary music score. Melodies have been used to define what the actors are not enthusiastic or are incapable to communicate hence can stream emotional support for the film.

Principles of international diversification Essay Example for Free

Principles of international diversification Essay The perspective that it needs to focus on some aspect of an investment that is responsible for funds that are diversified internationally both by market and by asset. At times a more theoretical comment may also be presented, as many of the ideas and principles of international diversification have been the subject of internal research. Various markets in which international diversification must be applied; exchange markets, money markets, and equity markets. But more often true with statistically oriented academic literature, the study lags the developments in the real world by not including in the analysis the rapidly growing share of the global investment. The report were prepared in accordance with generally accepted accounting principles applied on a consistent basis and are not misstated due to material fraud or error. The financial statements include amounts that are based on managements best estimates and judgments. Management also prepared the other information in the annual report and is responsible for its accuracy and consistency with the financial statements. Established and maintains a system of internal control that provides reasonable assurance as to the integrity and reliability of the financial statements, the protection of assets from unauthorized use or disposition, and the prevention and detection of fraudulent financial reporting. The system of internal control provides for appropriate division of responsibility and is documented by written policies and procedures that are communicated to employees with significant roles in the financial reporting process and updated as necessary. Management continually monitors the system of internal control for compliance. A corporate compliance plan as it helps reduce the risk of compliance errors and can limit the liability of directors and management. An effective plan can also reduce liability under the federal sentencing guidelines. Best of all, a corporate compliance plan helps employees follow the laws and enables management to know that the laws are being followed. The founding a comprehensive compliance program in which commonly known as corporate ethics program code of conduct has a number of benefits that goes beyond the direct compliance related aspects. The vast majority of employees want to do the right thing, and they want to work for a company of which they can be proud. They also want some way to make sure that the company does the right thing, so hotlines or other ways to report wrongdoing are appreciated. Empirical studies confirm that how the corporation approaches ethics and legal compliance management has a significant impact on employee’s attitudes and behaviors. Further Extensions: The focus of this research project is to develop approach that is best practice for sourcing ascendancy, process synchronization and information integration in the context of business research. The study aspire to first build a conceptual framework for business research opportunity that will make possible the development of solutions to the management challenges associated with achieving a companys strategic goals its operational constructs procedure has centered or build the organization with a business research course that has led to in receipt of enhanced business performance from arranging a process of direction within an organization A team oriented functioning in a environment and strong feelings of possession are also anticipated by a lot and as a consequence of or probably an indispensable component of a business research. There were several approaches that can be used to measure within the constructs and they are domain sampling, coefficient data and factor analysis and I used the analysis factor, explaining its component using the data to study the scale fundamental the construct. This analysis was used to examine whether the number of scope conceptualized might be established empirically. The preliminary examination results might show problems with more than a few events along with the mechanism of research. As the outline of the research it is significant to have a steadiness as it is only a part of construct strength. In sort to institute the construct weight of a measure, the amount to which the evaluate show a relationship with other events premeditated to calculate the similar problem and whether it conclude behave as anticipated it required also to be explained The authenticate of the construct of business research within an organization and shaped a useable instrument for diagnostic dimension of this construct. And the outcomes of business research opportunities within an organization appear to be applicable. Portfolio will have process that is constantly checking the index partition for the solution of other conflict groups and makes a queue, by indices of the partial solutions with the order of queue, so that the portfolio is able to proceed with the optimal task receive order flows from international traders and investors in the retail market and trade open positions with speculators in the wholesale market. The larger the open positions the more volatile the exchange rate has to be in order to equilibrate the wholesale market and the costlier the closing out of the positions for the intermediaries. However, the larger the predictable trading volume the smaller the revenues each currency unit exchange has to generate so that the dealer breaks even. Transaction costs of currency exchange can thus decrease with trading volume and will always increase with exchange rate volatility as well as dealers’ fixed costs. However, with the new framework not only s single but also several vehicle currencies can emerge, depending on the fundamental payments flows, the initial structure of exchange and dealer expectations about it, the market-specific volume-volatility relation and the structures of fixed costs for making markets and for opening formerly inactive markets. Moreover, both trading volumes as well as exchange rate volatilities are endogenous to the optimal exchange pattern. Those currencies with high fundamentals-based trading volume and low exchange rate volatility with respect to all or a sunset of currencies can emerge as vehicles. While in the goods market approach the idea is that exchange rates are determined basically through the trade of real assets, the asset market approach points to the importance of capital flows. The concept of purchasing power parity states that the exchange rate equates the national price levels of two countries in the sense that the PPP of a unit of currency is the same in both countries. A theory of exchange rate determination, it asserts that the exchange rate change between two currencies over any period of time is determined by the change in two countries’ relative price levels: Conclusion: To appreciate fully the arguments advanced in favor of international portfolio diversification, it is useful to have some knowledge of modern portfolio theory. Those readers familiar with Professor Markowitz’ seminal contribution need little further introduction to this subject. For others, it is useful to start with a brief theoretical overview of the effects of combining investments in two stock markets into an international portfolio. The expected return on a two-market international portfolio is simply the expected return in each market weighed by the fraction invested in the market. The variability of returns for this international portfolio is slightly more complex since it depends both upon the variability of each of the two markets held and the degree of co-movement or correlation between them. One of the key elements of the company’s value system, its basic beliefs, and another fundamental element is the business environment in which the firm conducts business. Then there are also the heroes of the company, plus its day-to-day routines and special ceremonies. Finally, there is the cultural network, the informal communication system within the firm. The many realities of the business world in which a firm operates play a major role in carving out the firm’s character and culture. Some aspects of the business environment have a very subtle influence. But as relentless winds and waters can erode jagged boulders to a smooth finish with the passing of years, so are some cultures gradually shaped by constant pressures from the marketplace. Since the company had run down the effects of estimated 46% of the loss revenue, the company is having a growing problem as its hold its position in undertaking the proposals, since it can plunge into worse than what is expected with the companies in such industry. Certain procedures, or frameworks or types of information, symbolically come to represent rationality within particular epochs, cultures or ways of thinking. Foreign direct investment in developing countries has long history; it has fluctuated over time, as investors have responded to changes in the environment for investment, including government policies toward foreign direct investment and the broader economic policy framework. After all the data was gathered it now the time that the management will consider possible strategies to spar the said problems, they are given possible strategies to choice which one would suit best their situation, application of such strategy is controlled well by the management for every plan is considered crucial until they iron up all this problems. Foreign direct investments in developing countries have flowed mainly into manufacturing and processing industries. It has traditionally been concentrated in a small group of countries, which partly reflects the size of their economies. Reference: 1. Elton, E. J. and Gruber, M. J. (2003). Modern Portfolio Theory and Investments Analysis. (6th edition), Wiley New York 2. .Elton. E. J and. Gruber, M. J. (1977). Risk Reduction and Portfolio Size: An Analytical Solution The Journal of Business, Vol. 50, No. 4. (Oct. , 1977), pp. 415-437.

Efficiency Of Step Down Transformer Biology Essay

Efficiency Of Step Down Transformer Biology Essay This extended essay deals with the efficiency of step down transformers in relation the current drawn in the secondary coil. Transformers are one of the most widely used components in electronic devices. Due to its ability to effectively convert voltages to a desired EMF (electro motive force), I thought that analyzing the efficiency of such a device could provide valuable insights for in order to cut power losses; an issue that is becoming a growing concern with the depletion of fossil fuels. My initial hypothesis was that a greater current drawn in the secondary coil would result in a greater efficiency. This was based on a mathematical proof. My experimentation with the step down transformer gave me results that supported my initial hypothesis, thus suggesting that the efficiency increased with an increase in current drawn. This was plotted on a graph, and a linear relationship was obtained. The data was not as precise as preferred, as there were reasonable errors with efficiency. However, this was due to the equipment used. The data that I collected was highly accurate as the R2 value of the graph obtained was 0.985. The strong evidence in favour of the relation has led me to believe that an optimum output current can be identified for each device to minimise power loss in the device as a whole. Considering the number of electronic devices that use transformers today, it will assist in ameliorating the energy crisis. However, further research as well as inclusion of step up transformers will provide more conclusive evidence. Word Count: 254 Contents Introduction: Power Transmission The electricity that is generated at the power stations has to be brought to our households and industries to be of any use. The power could be brought to us in two ways : By using a low voltage and high current By using a high voltage and low current This is true because of the relation P = VI, where P is power, V is voltage and I is Current; so in order to keep the power constant as the voltage increases the current must decrease and vice versa. If option 1 high current and low voltage is used, then there will be a tremendous loss in energy. As the current passes through the wires connecting the power stations and our homes, there is a heating loss which is equal to I2R. So, greater the current, greater the loss in energy. Hence it would instead be more viable to use extremely high voltages and miniscule currents in order to transport the electricity. However, in order to avoid the heating loss, the electricity is transported at a voltage which is of the order of 106 Volts, while are household appliances run on current with a voltage of about 10 -20 Volts. Thus a device is needed which can alter the voltage of the current. This is where a transformer comes in. Transformer Figure Source: http://www.constructionknowledge.net/electrical/images_electrical/transformer.jpg, February 6th, 2010 A transformer consists of a soft iron core with coils of wire on either end. It works on the basic principle of electromagnetic induction. Thus when a current is passed through the primary coil, a second current is induced in the secondary coil. However, in order for there to be any induced current in the secondary coil, the voltage in the primary coil has to be continuously altering (which will result in a change in magnetic flux associated with the secondary coil). Hence, an AC current has to be used. Depending on the ratio of turns of the primary coil to the secondary coil, the transformer can be step up or step down. If the primary coil has more number of turns it is a step down transformer while if the secondary coil has more number of turns it is a step up transformer. As with any other device, transformers are not 100% efficient. Transformers loose energy in four main ways Heating loss in the wires Formation of eddy currents Hysteresis loss in the transformer core Back emf induced by the secondary coil In this essay, I shall focus on efficiency of step down transformers, and how it is related to the current obtained. Efficiency In any device efficiency is defined as power output divided by power input. When specifically related to transformers, efficiency refers to the ratio between the power in the secondary coil and the power in the primary coil. As said before, power is measured through the formula P = VI, and due the losses of energy stated, the efficiency is never 100%. Hypothesis If the power in the Primary coil is Pp with a voltage Vp and current Ip, and the power in the secondary coil is Ps, with voltage Vs and current Is, the efficiency, . Since my focus is limited to the relationship of current in the secondary coil, I shall attempt to keep the power in the secondary coil constant. Thus, the by varying the current and voltage in the primary coil, I will be able to vary the the current in the secondary coil. If for different I values, the input power changes, then the efficiency too will change indicating a relationship. My hypothesis is that the efficiency will be related to the current in the secondary coil. This is because three main modes of losses in energy in transformers are related to current. Hysteresis is proportion to the square of the current, heating losses are calculated by the formula I2R and back emf too depends on the current in the secondary coil. Thus, variations in current will affect power loss, and hence energy. However, a linear relationship is not expected. Firstly, there are three different quantities that are being affected, and second, each of those quantities themselves are not linearly related to current in the secondary coil. This experiment could help in assessing the optimum current that should be drawn in order to ensure optimum efficiency. This would have major ramifications in devices which use transformers; for example, electric arc welders use extremely high currents at extremely low voltages. This results in heat loss through I2R which would melt the metal. Hence, step-down transformers are essential components of electric arc welders. Thus, if the efficiency were to depend on the current drawn, (as I hypothesize), it would have to be taken into consideration by producers and consumers alike. Mathematical Proof of Hypothesis However, the problem may not be as simple as it looks. Since the current affects energy loss in three different ways, a change in it may cause the energy losses to change in different ways. Thus if one mode of loss of energy increases with increase in current, while the other two are inversely proportional, this experiment may not be able to accurately explain the separate components individually, but should be able to identify the optimum current as it takes into account the net effect of the change in current. Interestingly, keeping the power output constant will allow me to keep the numerator of efficiency constant. If I take ÃŽÂ ± to be the energy lost, then the equation becomes: The initial ratio should be equal to 1 as the total power induced in the secondary coil plus the energy lost should be equal to the energy in the primary coil; this is derived from the principle of conservation of energy. Taking this to be a y= mx+c graph, one would assume that ÃŽÂ ± is the c. However, since in this experiment, power output is kept constant, becomes the c. Hence, for the equation to be of the form y=mx+c, it should be modified to:` However, in order to derive a relationship between the energy loss and the input current alone (as a first step to later deriving the function between efficiency and output current), I will have to have only two variables in the equation. Since Vp is a function of current, i.e. Vp = IpR and let as it is a constant, the equation can be further simplified to: Since, I am looking to minimize energy loss or, differentiating the equation should give a rough indication as to the trend to be expected. Differentiating with respect to Ip Minimizing means that should be as low as possible, ideally 0. Thus when becomes 0, becomes 0. Hence, lower the value of Ip, lesser the energy loss. What this implies is that the opposite would be true in the secondary coil a low primary current means a high secondary current. Thus, the heat loss should be the least when the current in the secondary coil is high. However, this might be a special case, as here the power in the secondary coil is constant. While the math does give me a basis on which to form a hypothesis, and could help explain the results if they support the hypothesis, it cannot be used directly in my data processing. The main reason for this is that the resistance of the circuit is unknown in my experiment. Though I am influencing some portion of it through the resistance box, there is no way that I can determine the resistance of the entire circuit. Hence, I will not be able to use the equation directly in my processing. Instead, I will use a slightly approximate method that will help me identify the trend, though it would not help me quantify the resistance. I will use a graph of efficiency versus output current. Thus, based on the trend that I get, I could verify if the initial hypothesis was correct if efficiency increases with output current, the hypothesis would be proven correct. Design of the experiment The biggest difficulty in the design of the experiment is maintaining the output power constant. Now, the only way that this can be achieved is through trial and error. Also, varying the input voltage to current ratio, will vary the output voltage to current ratio in the opposite way (assuming no variation due to energy losses). Thus the varying of the input V-I ratio will also assist in developing the ÃŽÂ · versus Is graph later on. One of the major drawbacks of this design and line of reasoning is that it is not taking eddy currents into consideration at all. Therefore I will use industrially manufactured transformers which have heavily laminated cores. This will ensure that eddy currents are reduced as much as possible. Using industrially manufactured transformers however has its own set of problems. The transformers that can be used for this experiment (as in small size, of operation specifications such as 220V-12V or 6V-220V) can hold only small currents (a maximum of 2-3 A). Hence, the range of readings I will be able to obtain will be limited to some extent. Even the industrially manufactured transformers hardly ever have efficiencies in excess of 50%. What remains to be seen though, is how this ratio changes with a change in the current drawn. The Circuit The circuit has to be properly equipped to keep the power output constant. The power supply will be a dimmer stat as this will allow me to place a variety of voltages across the circuit. I will also use a load/rheostat in the secondary coil so that I can keep the power constant even with changes in efficiency for example, if the efficiency increases with increasing current, a n increase in voltage in the primary coil will result in a greater increase in power in the secondary coil than before. The resistor will help me neutralize these variations. This set up will then be connected to an ammeter, and then the primary coil of the transformer. The secondary coil will have an ammeter connected in series and a voltmeter connected in parallel. Data Collection and Processing The first step in the data collection is to identify the raw data table. Since the variables that I am measuring are the currents and voltages in the primary and secondary circuit, these values will be part of my raw data table. Also, integral to the design are the chosen power output and the resistance that is being applied on the secondary coil to ensure this. Hence, these two will also be an important part of the raw data table. Thus the data table will look something like this: I have included one example to elucidate my data collection and method of processing Output Power Output Current Output Voltage Input Current Input Voltage 1.3936 8.71 0.160 2.61 1.610 The data however needs to be processed further in order to be interpreted. I first need to calculate the input and output powers. Both are calculated the formula P = VI. Since, I am trying to keep the output power constant, the output power is predetermined at 1.39 W. The input power is hence 2.61*1.610 = 4.2021W. The efficiency is hence, , = = 0.3316 This same process is repeated for every reading that I took, and hence I got my processed data table. The processed data table will consist of the output current and the efficiency with their respective uncertainties. The error propagation is described below, while the graph follows after. Processed Data Table Output Current in mA (I) Uncertainty in mA  ±ÃƒÅ½Ã¢â‚¬ I Efficiency (ÃŽÂ ·) Uncertainty  ±ÃƒÅ½Ã¢â‚¬ ÃƒÅ½Ã‚ · 7.81 0.05 0.3065 0.01720 8.71 0.05 0.3316 0.01965 4.82 0.05 0.2071 0.00962 5.09 0.05 0.1928 0.00896 4.92 0.05 0.1859 0.00854 4.90 0.05 0.1852 0.00849 7.41 0.05 0.2816 0.01529 6.23 0.05 0.2417 0.01220 5.83 0.05 0.2224 0.01086 8.22 0.05 0.3165 0.01825 4.12 0.05 0.1714 0.00757 3.24 0.05 0.1292 0.00555 3.69 0.05 0.1562 0.00674 4.39 0.05 0.1791 0.00803 3.88 0.05 0.1422 0.00614 Error Propagation: Errors are a very important part of any experiment, as no process is perfect. Since readings are not perfectly precise, the upper and lower limits of uncertainties in the values have to be defined. I will start with the uncertainties in raw data. Uncertainty for current output:  ±0.05mA This is determined due to the random error involved. The systematic error was only 0.01mA (the least count of the digital multimeter), and as the random error was greater, it was discarded. The random error was quite big since there were fluctuations in readings. I took multiple repetitions for a couple of currents, and hence determined the random error. So for output current the repetitions are shown below: Reading 1 Reading 2 Reading 3 Uncertainty 4.86 4.94 4.90  ±0.04 8.65 8.77 8.71  ±0.06 Hence average uncertainty is (0.04 + 0.06)/2 = 0.05 Thus the absolute uncertainty for output current was determined to be  ±0.05 mA. The same process of taking multiple readings for each of output voltage, input current and input voltage. Interestingly, uncertainty in input current was the same as that of output current which is  ±0.05mA, while the uncertainties in both input and output voltage were  ±0.005V. Though it would have been more precise to take multiple readings every single time, this proved to be very difficult due to the limitations of the dimmer stat. Hence, I took multiple readings only for 2 values in each of them. Quantity Reading Uncertainty Input Current 3.120  ±0.05mA Output Current 4.900  ±0.05mA Input Voltage 2.417  ±0.003V Output Voltage 0.285  ±0.003V These errors have to be taken forward to the respective powers as well. Since P = VI, Power Input = Vi*Ii, = 3.12*2.417 = 7.5410mW =  ±0.13645mW Similarly, Finally since , Hence and This method of error processing is done for every reading. I have shown only one example her, but the rest are in the appendices. Now that the processed data as well as the errors have been defined, a graph can be obtained. The graph is basically the efficiency versus the output current. This will help identify the trend and hence the implications. Graphical Analysis The graph is a straight line graph showing a direct relationship between efficiency and output current. Since the variables are directly proportional, the greater the output current, the greater the efficiency. The current has been taken on the x-axis as it is the independent variable while the efficiency is on the y-axis as it is the dependent variable. The error bars have been included. However there are two anomalous points (3.88, 0.1422) and (4.82, 0.2071). A line of best fit has been incorporated with an R2 value of 0.985 which indicates very accurate data. Thus the data that I have collected supports the initial hypothesis that I made. While I have mathematically supported the hypothesis earlier, the physics-explanation is still left. In order to answer this, I will look at each of the three current related sources of energy loss separately. I will start by analysing the heating loss in the wires of the transformers. This is determined by the formula I2R; since the resistance can be rewritten as , the heating loss can be rewritten as . Thus, since the heating loss is directly proportional to the length of the wire, the longer the wire the greater the loss in power. As the current output is large, it implies that the current input is low, which means that the transformer is a step down transformer. Since in a step down transformer, Ns Next, we come to hysteresis loss. Hysteresis loss, according to an article by the eccentric scientist Nikola Tesla, is proportional to the square of the input current. Thus, it can be inferred that the efficiency increases with increasing current in the secondary current as the hysteresis loss follows the opposing trend. Last but not the least, we come to back emf. Interestingly, this source of power loss also fits the hypothesis. Back emf refers to the emf that is re-induced by the secondary coil in the primary coil. This emf, thus opposes the initial emf that is present, and in overcoming this, there is some loss of power. Thus, the greater the change in emf in the secondary coil, the greater the power loss due to back emf. As current increases in the secondary coil, the emf reduces, and hence so will the change in emf due to the alternating magnetic flux. Thus, a greater secondary current will reduce power loss due to back emf as well. Thus we have seen the physical explanations for the data that I had collected. As I said earlier, one major problem is the complete negligence of eddy currents. That however cannot be helped given the limitations of my design. Application of findings to real life: The above findings have great implications on any device that uses transformers. Due to the relation that has arisen, a higher efficiency is an inherent property of any step down transformers, while consequently, step up transformers tend to have lower efficiencies. Thus producers and consumers of devices which use these transformers need to take this into consideration. Take the electric arc welder for example. This is device that works at extremely low voltages with extremely high currents. Thus, the normal 220V that is available on the mains has to be stepped down, and hence it uses a step down transformer. Thus, the efficiency of the device would tend to be reasonably high. Extending the same ideas to power transmission systems, the opposite effect is noticed. Due to the Joule heating effect, power is normally transmitted at high voltages and low currents. Hence when it reaches the households, the power has to be stepped down. Here though, the relative change in voltage is comparatively far lesser than in the electric arc welder. Thus the efficiency here will be a lot lesser than in the electric arc welder. Thus, this power loss has to be taken into consideration when planning out the power transmission systems. The optimum voltage to current should be determined so that the total power loss between the transformer, as well as the wire should be as less as possible. Thus, using the relation from this data as well as the Joule-heating effect, the power loss has to be minimized for the whole system and not just the loss during transmission in the wires. Conclusion and Evaluation Source of Error Like any other experiment, there are errors are present here.. These were: First, eddy currents were not taken into consideration. In order to overcome this, I used laminated cores. The problem with eddy currents is that they cannot be quantified using the data I could collect, and hence I could not calculate them. Also, it is next to impossible to nullify them completely. However, as this was present through all readings, it becomes a part of the systematic error. As this is negligible (the x-intercept of the graph is very close to 0), it can be concluded that eddy currents did not affect the readings by much. The second major source of error was my crude method of keeping power output constant. Starting with the insensitive dimmer stat, I could not control the power output to more than 3 significant figures. Thus there were variations in the power output which were of the order of 10-3. This too would have added to the error caused. This though would have been part of the random error, as it varied from reading to reading. However, due to the fact that multiple readings were taken, the error would have been minimized. Another source of error is the resistance in both circuits. The resistance in both circuits was unknown. Though I did determine some portion of the resistance through the resistance box, the wires were not ideal, i.e. they too had a resistance of their own. The power loss from these wires is thus not accounted for. To be more accurate, this too should be calculated and subtracted from the total power loss to get the power lost only in the transformer. Improvements in design: First of all, a more sensitive dimmer stat must be used. This basically means that the least count of the dimmer stat should be 1mV so t5hat fine tuning can be done. Second, wires of known resistivity and length should be used. This will help make the readings more accurate as then power lost in the external circuit can be removed. Also, I used only 1 transformer throughout my experiment. Though multiple readings were taken, random error could have been further minimised by using multiple transformers. Scope for further research My experiment was limited to just step down transformers. Though a relation was identified, it remains to be seen whether the relation will hold or become the opposite with step up transformers. The reason behind this is that the turns ratios of step up transformers follow an opposite trend to that of step down transformers, i.e. in step down transformers Ns Reflections For me, this extended essay was much more than just a requirement to be fulfilled in order to complete the IB Diploma. Throughout this process I have gained valuable hands-on experience which I am sure will help me in my further studies. Apart from pushing the boundaries of my knowledge, I have also developed my research skills. Not only have I figured out how to go about a basic research project, but I have also learnt not to be disappointed in the face of setbacks. This essay was my third one, as problems arose in the first and second ones. Although I was initially disheartened, now I regard them as being equally important experiences, as I have realized that failure is part of any scientific process. In fact, it was the first couple of failures that helped me understand the subject better than I could have hoped. Personally this was a deeply enriching experience that I know will assist me for a long time to come. Bibliography Feynman, R. P. (2005). The Feynamn Lectures on Physics, The Definitive Edition Volume 2. Addison Wesley. Halliday, R. a. (2004). Fundamentals of Physics. Wiley. Heathcote, M. J. (2007). The J P Transformer Book: A Practical Technology of the Power Transformer. Newnes. Tsokos, K. A. (2008). Physics for the IB Diploma. Cambridge: Cambridge University Press. http://en.wikisource.org/wiki/The_Losses_Due_to_Hysteresis_in_Transformers http://www.citycollegiate.com/transformers2.htm http://www.constructionknowledge.net/electrical/images_electrical/transformer.jpg http://www.copper.org/applications/electrical/energy/trans_losses.html http://www.elkor.net/pdfs/AN0305-Current_Transformers.pdf http://www.allaboutcircuits.com/vol_2/chpt_9/2.html http://www.conformity.com/artman/publish/printer_47.shtml http://www.losgatosmanufacturing.com/classes/handouts/arc_welding_unit.pdf Appendices Appendix 1 My raw data is presented below Output Current in mA (Is) Output Voltage in V (Vs) Input Current in mA (Ip) Input Voltage in V (Vp) 7.81 0.179 2.65 1.721 8.71 0.160 2.61 1.610 4.82 0.290 3.01 2.242 5.09 0.273 3.09 2.333 4.92 0.283 3.12 2.401 4.90 0.285 3.12 2.417 7.41 0.188 2.75 1.799 6.23 0.223 2.85 2.017 5.83 0.239 2.94 2.131 8.22 0.169 2.63 1.669 4.12 0.338 3.28 2.477 3.24 0.430 3.51 3.073 3.69 0.376 3.49 2.545 4.39 0.317 3.21 2.420 3.88 0.360 3.41 2.880 Appendix 2 The processed data without the errors is represented below: Output power in mW (Ps) Input Power in mW (Pp) Efficiency (ÃŽÂ ·) 1.3980 4.5607 0.3065 1.3936 4.2021 0.3316 1.3978 6.7484 0.2071 1.3896 7.2090 0.1928 1.3924 7.4911 0.1859 1.3965 7.5410 0.1852 1.3931 4.9473 0.2816 1.3893 5.7485 0.2417 1.3934 6.2651 0.2224 1.3892 4.3895 0.3165 1.3926 8.1246 0.1714 1.3932 10.7862 0.1292 1.3874 8.8821 0.1562 1.3916 7.7682 0.1791 1.3968 9.8208 0.1422 Appendix 3 This is the data with the uncertainties included. Output Current in mA (Is) Uncertainty in mA (ΆIs) Output Voltage in V (Vs) Uncertainty in V (ΆVs) Output power in mW (Ps) Uncertainty in mW (ΆPs) 7.81 0.05 0.179 0.005 1.3980 0.0480 8.71 0.05 0.160 0.005 1.3936 0.0516 4.82 0.05 0.290 0.005 1.3978 0.0386 5.09 0.05 0.273 0.005 1.3896 0.0391 4.92 0.05 0.283 0.005 1.3924 0.0388 4.90 0.05 0.285 0.005 1.3965 0.0388 7.41 0.05 0.188 0.005 1.3931 0.0465 6.23 0.05 0.223 0.005 1.3893 0.0423 5.83 0.05 0.239 0.005 1.3934 0.0411 8.22 0.05 0.169 0.005 1.3892 0.0496 4.12 0.05 0.338 0.005 1.3926 0.0375 3.24 0.05 0.430 0.005 1.3932 0.0377 3.69 0.05 0.376 0.005 1.3874 0.0373 4.39 0.05 0.317 0.005 1.3916 0.0378 3.88 0.05 0.360 0.005 1.3968 0.0374 Input Current in mA (Is) Uncertainty in mA (ΆIs) Input Voltage in V (Vs) Uncertainty in V (ΆVs) Input Power in mW (Ps) Uncertainty in mW (ΆPs) 2.65 0.05 1.721 0.005 4.5607 0.09930 2.61 0.05 1.610 0.005 4.2021 0.09355 3.01 0.05 2.242 0.005 6.7484 0.12715 3.09 0.05 2.333 0.005 7.2090 0.13210 3.12 0.05 2.401 0.005 7.4911 0.13565 3.12 0.05 2.417 0.005 7.5410 0.13645 2.75 0.05 1.799 0.005 4.9473 0.10370 2.85 0.05 2.017 0.005 5.7485 0.11510 2.94 0.05 2.131 0.005 6.2651 0.12125 2.63 0.05 1.669 0.005 4.3895 0.09660 3.28 0.05 2.477 0.005 8.1246 0.14025 3.51 0.05 3.073 0.005 10.7862 0.17120 3.49 0.05 2.545 0.005 8.8821 0.14470 3.21 0.05 2.420 0.005 7

American Airlines Flight 1420 Essay -- Essays Papers

American Airlines Flight 1420 American Airlines flight 1420 crashed in Little Rock, Arkansas. The crash killed 11 people, after running off the runway and impacting an approach lighting structure. The causes of the crash are still being investigated but the likely causes include the plane touching down 2000 feet passed the runway threshold, the rapidly deteriorating weather, and a fatigued flight crew. The American Airlines McDonnell Douglas MD-82 carrying 143 passengers attempted a landing in fierce winds just shy of midnight on June 2, 1999. As the flight was en-route to Little Rock the Air Traffic Control (ATC) facility at the Little Rock Airport reported to the pilots that a thunderstorm had moved into the area with strong wind gusts. Despite these reports the flight crew decided to continue on. While the plane was on final, ATC informed the crew of rapidly deteriorating weather and two wind shear alerts. The co-pilot said that they had sight of the runway the entire time they were on final; he said it was like â€Å"a bowling alley effect† (Lunsford 1) where they were able to see between the clouds. As the plane touched down things started to go wrong. Immediately after touching down the plane started hydroplaning down the runway. The crew did not feel the typical deceleration forces that are normally associated with the reverse thrusters that are used when landing. With the strong wind on the field the plane started to yaw to the right due to a strong crosswind...

Punks :: essays research papers

Punks Did you know that the first commercially successful punk band was the Sex Pistols? Then came groups like Black Flag, Husker Du, and Bad Brains. Punk was invented in Britain in the mid Seventies. The first American punk started in a New York club called CBGB's. CBGB's would attract a crowd of about 500 with its Sunday-afternoon hard-core matinees. The concerts would be over by a reasonable time so kids could get home to eat dinner with their parents. In this paper we will take a look at some history and aspects of punk rock over the years. Slam dancing has been popular through the history of punk. You may have heard of called "mashing" or "stage diving." Mashing is just a big game of bumper cars like you played when you were a kid. I think Natalie Jacobson who is dating the lead singer of "Murphy's Law" describes stage diving best when says, "It's like diving into a human carpet. Something like the old kids' trust game. Just my way of getting into it. Gospel people got their thing, I got mine."1 Some punks consider themselves Nazis', or are concerned with issues like peace, racism, and nuclear war. Most punk is against parental, musical, and political authorities. On the other hand some isn't. Bob Mould of Husker Du talks about politics quite frequently in his songs. Most punks that live in small towns have trouble making friends. They find it hard to relate to most people. Sixteen- year-old Becca Levine finds it hard to make friends in her small town. She comes from a family of divorced parents that never have understood her. Her mother thinks it's just a phase she's going through. As Becca Quotes, "Parents around here treat me like I'm kind of weird."3 She has met someone from New York City that understands her. She meets with him at concerts at clubs like the Ritz or CBGB's. She met someone else also.