Rhetorical Analysis Essay Example | Topics and Well Written Essays - 1000 words - 1

Rhetorical Analysis - Essay Example The appeal made by Jim Hightower in this article is replete with ample logical insights and arguments that cater to the logical faculties of the target audience and is rich in verifiable ethical claims that are aimed at arousing the ethical concerns and interests of the American consumers. The ethical credibility of the claims made by Jim Hightower is to a great extent established and reinforced by the character and professional credentials of the author. The target audience in particular and the readers in general can readily believe the claims being made by the writer as the character and qualifications of the writer evince much respect and credibility. Jim Hightower is indeed a very versatile American personality, who happens to be a radio commentator, public speaker, author and writer (Jim Hightower 1). Jim Hightower has spent much time and resources, protecting and safeguarding the rights of the American consumers, common folks, small businesses, working families and environment alists (Jim Hightower 1). Jim Hightower enjoys the honor of being twice elected Texas Agriculture Commissioner (Jim Hightower 1). Jim has written many books to further his cause and his works include Thieves in High Places: They’ve Stolen our Country and its Time to take it back, There’s nothing in the Middle of the Road but Yellow Stripes and Dead Armadillos, If the Gods has Meant us to Vote they would have Given us Candidates and Swim Against the Current: Even a Dead Fish can go with the Flow (Jim Hightower 1). Jim Hightower has been known for vociferously voicing the concern of the common American masses and consumers and his articles enjoy much public interest and following. So, even a cursory perusal of the article The Price of Cheap Goods does convince the readers that the writer that is Jim Hightower is somebody that deserves serious attention and interest. In the article, Jim Hightower successfully manages to come out as somebody who happens to be an authority on the subject being discussed and dealt with (Swearingen 122). The tone, matter and the research behind the details unraveled in the article are sufficient to convince the readers that the writer that is Jim Hightower is somebody who is worthy of interest and is likable (Swearingen 122). The professional background and credentials of Jim Hightower are sufficient to imbue the article with an aura of character and credibility. The tone and style adopted by Jim Hightower in the given article as conveyed by â€Å"It’s common to find child labor, sixteen hour days, constant exposure to lead and other poisons, wage rip-offs and other abuses in factories that stock the shelves of our stores and line the pockets of our corporate CEOs (Hightower 46),† does attract much credibility and trustworthiness on the part of the American consumers. In the given article, Jim Hightower inclusively resorts to verifiable logical means backed by

Live Music Event Essay Example | Topics and Well Written Essays - 3000 words

Live Music Event - Essay Example A survey was conducted to determine the target audience and also the most appropriate music category. The youths and women form the bulk of live music audient at 50% and 77.3% respectively. The event organizers used four promotional approaches; Facebook, posters, flyers and promotional videos. The financial objective was achieved, because the event achieved a profit of $142. The 229 Venue was established in 1965 at the International Students House. The facility was refurbished in 2007, and presently it has superior music equipment and systems. They key players during the event were; the audience, performers, and the event organizers. The event was guided by legal considerations, because all the parties adhered to the conditions set by the booking form. The promotional and organizational activities were successfully conducted based on a time schedule, from January 2, 1015 to February 12, 2015. The event was generally successful. The report discusses an urban even. The event was conducted at the 229 venue, located along the Great Portland Street in London. The music event took place on February 13, 2015, between 8pm and 11pm. The theme and title for the event were referred to as "Fresh out of Urban." The theme was very effective in illustrating the urban environment that influenced the acts (Lebrecht 2009). The event also resonated adequately with the London youths, who were the key target audience for the show. The events management team conducted a research survey, with the aim of identifying the entertainment market needs. The survey provided adequate information, which was successfully utilized during the event and artist management. The urban music genre was found to be very attractive to the mostly youthful population in London. Eight acts expressed interest to perform during the â€Å"Fresh out of Urban† event. However, only six managed to perform. The music acts that performed are; Pedro, Nata lie May, Tosin and Temi, JDX, Cazz Bang, Sizel

Risk assessment Essay Example | Topics and Well Written Essays - 2750 words

Risk assessment - Essay Example A risk based approach has been adopted for the development of a system for managing health, safety, and environmental risks. The system has been developed by benchmarking the system against international standards such as the ISO 2001. The components of the system include general requirements, SHE policy, planning, implementation and operation, measurement analysis and improvement, and management review. This section includes resources, roles, responsibility and authority. Competence, training and awareness have been addressed. Documentation, control of documents, operational control, and emergency preparedness and response have also been included. Probabilistic Risk Assessment (PRA) is an analytical method used to protect health and safety. The goal of PRA is to develop a method to predict concerns before they manifest in terms of loss, injury, or fatality. The calculation of risk involves mathematical representation and building model. Risk is related to the concept of safety, danger, hazard, loss, injury, death, toxicity, or peril. Risk is defined as , where ci is the consequence, and pi is the probability. Risk is expressed in terms of , average loss of life expectancy, or fatalities per 100000 persons per year (Ragheb, 2009). HSE (2007) has outlined five steps for the assessment of risks in the workplace. These include the identification of hazards; decision on who might be harmed and how; evaluation of risks and decision on precautions; recording of findings and implementation; and review of assessment and update as necessary. Sustainability in manufacturing includes product sustainability assessment, product design for sustainability, lifecycle issues in product design and manufacture, and product manufacture for societal impact. Product design and manufacture for societal impact includes personnel health, operational safety, security of personnel and systems, and work ethics. Manufacturing process should include environmentally conscious

Reificaition Case Essay Example for Free

Reificaition Case Essay Wikipedia defines reification as â€Å"(Lat. res thing + facere to make) n. the turning of something into a thing or object; the error which consists in treating as a thing something which is not one. Hypostatization, treating an abstract entity as if it were concrete, is a case in point†. In Marxist terms, it is the consideration of a human being as a physical object, deprived of subjectivity. According to Marxists, this is one of the pitfalls of the capitalist system because in such a system the laborers and their work are not valued to their proper extent. Their work is treated as a commodity and is valued according to the unpredictable needs of the market. This concept is closely tied to the Marxist idea of commodity fetishism which Wikipedia describes as â€Å"an inauthentic state of social relations, said to arise in complex capitalist market systems, where social relationships are confused with their medium, the commodity.† Marxist writer, Georg Lukà ¡cs, writes thus: The transformation of the commodity relation into a thing of ghostly objectivity cannot there ore content itself with the reduction of all objects for the gratification of human needs to commodities. It stamps its imprint upon the whole consciousness of man; his qualities an abilities are no longer an organic par of his personality, they are things which he can own or dispose of like the various objects of the external world. Simply put, Marxists criticize capitalist systems for stripping the human person of his social nature. He is transformed into a commodity or a product. One’s labor is transformed into money which is in turn used to purchase the products of other people’s labor. Although this may facilitate the exchange of goods, the problem of the system lies in the fact that because of this abstraction, the use-value (the actual usefulness of the object) is oftentimes totally different from its exchange-value (the value of the object in the marketplace). For example, a person who creates a hammer (which has a variety of uses) will be paid less than a person who makes jewelry (an object which has less use than a hammer). The value given to the work of the laborer is incommensurate to the work and effort that he made in order to produce the good. How can reification be avoided? Marxist measures against reification have proven themselves to be ineffective (including complete control over the market and standardization of wages). This is because these measures tend to remove the element of competition from the formula, thus, causing production to suffer instead. An alternative mode by which reification is avoided is through the respect of human rights. According to John Locke, each person has the natural right to life, liberty and estate which must be protected by the government. These rights must ensure that each person shall be given his due. By treating persons as individuals with human rights and dignity, people will be treated as an end and never as a means. The theory of human rights has been upheld and accepted by most of the world and are embodied in international instruments and conventions, most notable is the Universal Declaration of Human Rights. In the field of labor and employment, modern societies have integrated this idea of human dignity by setting minimum standards and conditions to be strictly followed by employers under the pain of appropriate sanctions should they be defied. For example, there could be a law saying that any employee who works beyond eight hours in a single day shall be given additional overtime pay. Another instance would be a law that would lay down a minimum wage based on the living standards and conditions of the locality where the worker belongs. By recognizing the human dignity of every person, reification is completely obliteration because persons are then given the respect they deserve. They are no longer treated as cogs in the machinery of production but are considered partners in the enterprise. By holding that each person deserves to be treated with dignity, they are esteemed as subjects never objects, and will be given their due.       Bibliography Lukà ¡cs, Georg. 1967. History Class Consciousness. Translated by Andy Blunden. Merlin Press. Smith, John, Bob Snider, and Diane Hill. 2005. A study of physics. New York: McGraw Hill. Wikipedia. 2006. Commodity fetishism. Wikipedia. http://en.wikipedia.org/wiki/Commodity_fetishism. Ashcraft, Richard. 1986. Revolutionary Politics and Lockes Two Treatises of Government. Princeton: Princeton University Press. Wikipedia. 2006. Georg Lukà ¡cs. Wikipedia. http://en.wikipedia.org/wiki/Georg_Luk%C3%A1cs. Wikipedia. 2006. Human Rights. Wikipedia. http://en.wikipedia.org/wiki/Human_rights. Wikipedia. 2006. John Locke. Wikipedia. http://en.wikipedia.org/wiki/John_locke. Wikipedia. 2006. Reification. Wikipedia. http://en.wikipedia.org/wiki/Reification.

Myth Being False and True Simultaneously Essay Example for Free

Myth Being False and True Simultaneously Essay One commonality nearly all past human cultures possess is that they attempted to explain the unknown through fanciful tales of Gods, Goddesses, Spirits or other magical beings that through some manner were able to control the weather and shape the world around them. Amongst these varied tales one particular set of myths stands out as being a common creation in past societies namely that of the birth of the World. It must be noted that nearly every single civilization that has come into being has had a creation myth as the foundation of their culture from which all other preceding myths are based upon. The reason for this is that it is basic human nature to try to question all that is around them and to attempt to answer these questions in whatever way is available. Since at the time of their creation most early civilizations did not quite grasp the scientific truths that we know of today as such they used myths to fill in the gaps so to speak. One problem with this method is that while they at times came close to the answer as to how the world was actually formed most of the time due to the exaggerated nature of some of the myths they were wrong more than they were right. What this paper will seek to do is show how the different creation myths of various cultures simultaneously got the facts wrong and right at the same time. Greek Myth of Creation The more popular aspects of Greek mythology are usually focused on the Olympic Gods and Goddesses and their various in fighting, squabbles and methods of interference with the people of Greek world one aspect that is rarely mentioned is the concept of how the Greeks viewed the creation of the world. Greek mythology states that initially the entire universe was composed of a great black void called chaos that was surrounded by a massive unending stream of water that was supposedly ruled by the ancient god Oceanus. This landscape of an endless stream of water and a great gaping void was said to tbe the domain of the Goddess Eurynome (Hamilton 1969). That in a desire to make order from the chaos she danced on the waves of Oceanus which helped to separate the sky from the sea and she also created the land from which she placed a plethora of creatures to populate it (Hamilton 1969). In some aspects the Greek story of creation did get some parts right when it came to describing the creation of the world. It is true that initially the early Earth was covered by a vast ocean with no landmass present at all and that there was also persistent storms that occurred as a result of erratic weather patterns at the time. It is also true that land masses were formed after the oceans receded and from this came the eventual rise of plant and animal life on the planet. In several aspects the Greek myth of creation was actually right however it is highly doubtful that a Goddess danced on the waves of the early Earth and created the landmasses we have today since there is no evidence to prove such a Goddess existed. Egyptian Myth of Creation Ancient Egyptian mythology states in the beginning there was nothing, that everything was darkness and all that existed was a great body of water named Nun. It was through the power of Nun that a great shinning egg came out of the darkness and this was the great God Re who could take many forms and was powerful enough that if he spoke of name that being or object came into being (El Aswad 2005). It was through Re speaking the names of the Egyptian gods that they came into being and the land, sun, stars and sky came into being. The one aspect that the ancient Egyptians got right was it is true that originally the was nothingness in the world and yes there was a great body of water on Earth during its early years however there has been no evidence to prove that a great shinning sentient egg caused the creation of the sun, sky and land merely by stating their names. Norse Myth of Creation Ancient Norse mythology states that initially there was a great void names Ginnungagap from which came a region of ice named Niflheim in the the North and Muspellsheim a region composed of fire in the south. It was the meeting of these two regions that melted the ice of Niflheim and created the frost giant Ymir who was eventually killed by Odin, Vili and Ve who formed the Earth from his flesh and the heavens from his skull (Columbia 2009). It must be noted that Norse mythology is incredibly fatalistic and is among the most depressing types of mythology to be read. It comes at no surprise that their concept of the creation of the Earth came out of death. All in all similar to ancient Egyptian mythology Nose mythology only got the notion of a formless void correct the parts regarding the formation of the Earth through the dead carcass of a giant is definitely wrong. Judeo- Christian Myth of Creation One of the most well known myths in the world today is the Judeo Christian myth of how the world was created by God in seven days. It must be noted that while it is true that this particular myth was the result of the early Judaic religion of attempting to interpret the creation of the world through God it is the time frame itself that is wrong (Mclaren 2006). While it may be true that there is a one true God the creation of world has been proven to have been the result of a process billions of years in the making. The myth did get several parts right though. The initial events of the creation of light could be stated as the start of the big bang, after which the creation of the starts, seas and landmass on Earth all follow a prescribed and accurate order as to how things were created in a step by step process. The creation of man though is something to be contended with since according to fossil records and Darwins theory of evolution man originated from apes and not from the ground. Aztec Myth of Creation The Aztec myth of creation is based upon the actions of Quetzalcoatl and Tezcatlipoca who looked down from their place in the sky and saw only water below. They attempted to create a mass of land on the water however a gigantic goddess that was floating on the water ate everything they made with her many mouths (Hofstadter 2005). As a result the two gods transformed themselves into giant snakes and tore her in two with her head and shoulders becoming the Earth and the lower part of her body the sky. From the hair of the goddess came the plants of the Earth, from her eyes and mouth the waters of the Earth and from her nose and shoulders the mountains, hills and valleys (Hofstadter 2005). The Aztec myth of creation is similar to that of the Norse myth of creation which states that the Earth was born from the decapitated body of a giant being. One problem with the Aztec myth of creation is that besides the point indicating that there was a giant body of water in the beginning of the Earths creation which is true the rest of the myth is highly inaccurate when considering the facts that are known today. For one thing, similar to this papers reaction to Norse mythology, the Earth was most certainly not created from the decapitated body of a giant goddess rather it was formed through the interaction of volcanic activity and receding oceans. Incan Myth of Creation The Incan myth of creation states that the Earth was originally covered in darkness and that from the lake Collasuyu emerged the Incan god Con Tiqui Viracocha who brought humans with him. When he emerged Con Tiqui brought forth the sun and stars and fashioned more humans from giant rocks that he found nearby (Feld 2000). When interpreting the Incan myth of creation it become obvious that while the Incans were aware of the concept of darkness covering the Earth it becomes clear that that myth assumes that when humans arrived on Earth everything was already formed and that all it needed was light in the form of the sun and stars. The Incan myth of creation is different from the other myths presented in this paper due to the fact that it states that there was no need for land and water to separate because everything was already arranged in the beginning. Besides the account of darkness covering the Earth most of the Incan myth of creation is highly inaccurate and is not an accurate account of what creation of the Earth was like. List of References Hamilton, Edith. Mythology: Timeless Tales of Gods and Heroes. Pg. 66 68. 1969. Warner Books: New York Ymir. Columbia Electronic Encyclopedia, 6th Edition (2009): 1. Maclaren, Alexander. THE VISION OF CREATION. 3-5. Project Gutenberg Literary Archive Foundation, 2006. Literary Reference Center. EBSCO. Web. 7 June 2010. Hofstadter, Dan. THE AZTECS: BLOOD AND GLORY. Smithsonian 35. 10 (2005): 76. MasterFILE Premier. EBSCO. Web. 7 June 2010. Feld, Evelyn Dana. The Inca creation myth. Calliope 10, no. 7 (March 2000): 36. MasterFILE Premier, EBSCOhost (accessed June 7, 2010). El-Aswad, el-Sayed, Jane Garry, and Hasan El-Shamy. Creation Myth: Cosmogony and Cosmology, Motifs A600-A899. Archetypes Motifs in Folklore Literature: A Handbook (2005): 24-31. Literary Reference Center. EBSCO. Web. 7 June 2010.

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

Pro-Anorexia Websites Essay -- Eating Disorders Pro-ana Internet

Pro-Anorexia Websites Cyberspace, something that was once considered a fad, has developed into a tool that allows people struggling with anorexia to potentially find a sanctuary from the regulatory systems in popular culture that are applied to women’s bodies. Cyberspace provides an alternative space for women with eating disorders or body issues. The space created by cyberspace is potentially safer for women to meet because it allows anonymity while simultaneously being part of a community that the built environment is unable to provide. The components that make up pro-anorexia websites are usually considered abnormal, repugnant, or deviant within popular culture, because popular culture does not accept the way anorexics interpret images of the body. This popular view of people with anorexia does not allow anorexics to function as an accepted part of public space or popular culture. The paradox of pro-anorexia websites serving as a sanctuary space for anorexics is that cyberspace is a public space. Since the pro-anorexia websites are public they not only serve as a sanctuary for women, but also act as a metaphor for the anorexic body. The anorexic body is a site of struggle and resistance, which is also true for the pro-anorexia website which is constantly threatened with being shut down because it is in opposition of the popular view of the body. In this paper, I explore the type of space that pro-anorexia websites create through the analysis of the components that most of these websites contain, such as, a warning page, definitions of eating disorders, discussion boards, ana doctrines, and â€Å"thinspiration† galleries. Pro-anorexia, also known as pro-ana, websites are a genre of websites ... ...s into the anorexic psyche and body. The websites are sites of contradictions, much like the anorexic psyche and body. They allow non-sufferers a new perspective on eating disorders, but also reveal some of the mixed messages presented everyday in popular culture. Works Cited â€Å"Ambrosia Refusal.† Home page. 06 December 2003. . â€Å"Ana’s Journal.† Home page. 08 December 2003. . â€Å"An Ana World.† Home page. 06 December 2003. . â€Å"The Anorexic Files.† Home page. 06 December 2003. . â€Å"House-of-Sins.† Home page. 06 December 2003. . â€Å"Rain Baby.† Home page. 06 December 2003. .