Abraham Lincoln1 essays

Abraham Lincoln1 essays regarded by many historians as the greatest president ever to stand at America's helm. This reputation is extremely well deserved, as Lincoln was able to preserve the Union and gain victory in the civil war, despite his fighting an uphill battle against his own presidential cabinet. Had he not been struggling against this divided government, President Lincoln could have achieved victory with extreme efficiency and a minimum of wanton bloodshed (Angle 659). After Lincoln was inaugurated on March 4, 1861, he was forced to battle a split cabinet because of campaign promises made to various Republican factions, which made it almost mandatory for certain individuals to be appointed to cabinet posts. He ruled his cabinet with an iron hand, and often acted without cabinet consent or advice. Although his opponents called his method of rule "dictatorial" and "unconstitutional," it was the only effective way to get anything done (Simmons 142). In the beginning, Lincoln's secretary of state, William H. Seward, clearly considered himself the President's superior, and blandly offered to assume the executive responsibility. He entered the cabinet with the thought of becoming the power behind the 2 Presidential chair and openly opposed Lincoln's control of the Union. This made Lincoln's position as Chief of State exceedingly difficult and hindered his communication and control of the military. As time passed, however, Seward recognized Lincoln's capabilities and gave him complete loyalty (Simmons 174). This could not be said of Salmon P. Chase, Lincoln's first secretary of the treasury. Blinded by an inflated ego, Chase pursued his own presidential aspirations. He was in constant conflict with Seward, and in general opposition to Lincoln, particularly over the issue of slavery. Chase has been described as "jealous of the President," and "overly ambitious." Lincoln's personal secre ...

Comparing Catcher in the Rye and Pygmalion and the Themes They Represent essays

Comparing Catcher in the Rye and Pygmalion and the Themes They Represent essays Comparing Catcher in the Rye and Pygmalion and the Themes They Represent In J. D. Salingers novel The Catcher in the Rye, the main character, Holden Caulfield, muses at one point on the possibility of escaping from the world of confusion and phonies while George Bernard Shaws main character of Pygmalion, Eliza Dolittle, struggles to become a phony. The possible reason for this is that they both come from opposite backgrounds. Holden is a young, affluent teenager in 1950s America who resents materialism and Eliza Dolittle is a young, indigent woman who is living in Britain during the late 1800s trying to meet her material needs and wants. These two seemingly opposite characters do in fact have something in common: they, like every other person, are in a constant pursuit of happiness. This commonality is the basis for the themes these two stories present. Some of these themes go unconsidered and this leads to many misunderstandings in the world. This is why Pygmalion and Catcher in the Rye are not just stories but, in fact, lessons that are presented in their themes. These themes teach that being middle or upper class does not guarantee happiness, treating others with good manners and equality are important, and pronunciation and terminology can put you in your place in terms of class. Throughout the worlds history, pronunciation and the way a language is spoken indicates ones place in society. This is quite apparent in Pygmalion. Eliza is a classic victim of being put into her place based on the way she speaks. She goes to Professor Higgins in hope that he will give her lessons on how to speak in a more refined. She says she wants to be a lady in a flower shop stead of sellin at the corner of Tottenham Court Road. But they wont take me unless I can talk more genteel (23). This is precisely why she comes to Henry Higgins. He knows ...

Greek philosophy Essay Example | Topics and Well Written Essays - 750 words

Greek philosophy - Essay Example Those performing exceedingly well receive ten years of mathematical education, the successful will move onto five years of training in dialectic and then a final fifteen year period of apprenticeship in managing the polis.† (Philosopher King). Plato developed the concept of â€Å"forms† which he said can be understood only by a well trained and knowledgeable person. The understanding of forms cannot be achieved through human senses and it is something beyond the normal existence of an individual which an average person will fail to understand. Plato also asserts that the mathematical knowledge is substantial for a philosopher king to know forms. It can be seen that, Plato give primary importance to education so that the philosopher is well groomed to be a king. Understanding the political climate of any state is important for its rulers. Plato gives a 15 year duration concentrating only on political concepts and ideas to make a philosopher fit to be king. Here, Polis not only includes the individuals in a state but the geographical peculiarities of the state are also taken into consideration. Plato does not support the idea of democracy as it does put the right person at the helm for making decisions in public, social or political affairs. He point out that such people will not be properly trained in knowledge and practical application of ideas. According to Plato, all individuals in a society are equal in a democratic setting which can lead to problems of great measure. Then he points out that every individual in a society cannot be equally trained to perform well with regard to matters of political concern and in a democratic setup of people with no capabilities contribute to political matters which can destabilize the peace of the society. In a democratic situation, people may select representatives who can be totally incapable of handling political

AAN case study Essay Example | Topics and Well Written Essays - 2000 words

AAN case study - Essay Example Many efforts have been put in place to protect personal and private data from infringement and theft for intellectual purposes or simply destruction by people considered enemies of the state. As such, many governments all over the world are in pursuit of reliable data monitoring, investigation and other intelligence driven motives electronics that will guarantee such an achievement (Barkan, et al., 2008, pp.392-429). Many countries, especially those in the Asian continent have appreciated the need for information security and they are now facing a very steep learning curve as they have embarked on evaluation and assessment of the new technologies in use and those in the market in order to establish their viabilities, vulnerabilities threats of security and their strength in ensuring that security threats are minimized or eliminated (Faisal, et al., 2007, pp.667-699). Various strategies have been put forward to help tackle security problems in India and the government has seen the nee d to indulge international firms that could be contracted to provide these monitoring and investigation electronic devices. AAN Limited is a company that deals in small electrical products that do have minimal intellectual property value compared with other companies that design the same. The company has sought markets within the Asian region in the past three years. Following this marketing campaign, AAN needs to bid for a contract that is highly ambitious able to impact the organization in a massive scale. This contract is owned by the Indian government where the contractor will have to design a variety of cutting edge electronic products that would be made use of in the secret services of India. The use of these products will be put to use in the monitoring and investigating those people who are a threat to the national security of India. The contract will be worth 144 million sterling pounds in the first two years and an additional sum of 134 million for the next three years aft er the first phase bringing the total contract to a value of 278 million sterling pounds per year. This report aims to address various issues related to security as far as the audit done on AAN case study is concerned. 2.0 Information Security and devices 2.1 Highly Secretive Organizations Highly secretive organization means being a firm that does not expose its dealings to the public. In this case, what happens within the organization is little known to people who are not selected to know. Such organizations deal with top secret or confidential information most especially that relating to the state security and other government machineries. Highly secretive organizations have been known to exist in the minds of many without necessarily having a name or label to identify them a factor which makes it even hard for non-involved party to discuss or even know anything about them in real life and what they do. Most of these secretive organizations are related to the states in which they operate and in their operations, they use high technology devices to track information, monitor movement of people and goods, and make various investigations with the aim of establishing more information that could be used for security purposes (Challa & Pradhan, 2007, pp.87-96). They also use cryptographic modules which do conform to high set standards that form what might be called approved security standards entailing cryptographic algorithms, key management techniques by use of cryptography, and techniques of authentication with the objective of protecting the government’s sensitive information or their own from the public and people considered threats to security (Garg & Verma,

Analysis Of Giddens On Agency And Structure Sociology Essay

Analysis Of Giddens On Agency And Structure Sociology Essay Anthony Giddens, a famous writer on society, had developed his thoughts in his books year after year. His book titled, Constitution of Society, written in the year 1986, has leaded him far ahead to achieve his goals. Each of the chapter, in this book; has covered the agency and structure theory and proposes good statements (Giddens, 1986). The author has clearly described what he means with the agency term. He has also given due focus on time and the social actions for space. The discussion on the ways of handling different norms by the people, and the social constraints that exists in the society, are done as well. In addition, he uses empirical research in his book to elaborate further the aspects associated with structure and agency within the society. The text thus discusses the routine practice, which becomes a social act as a principle of duality for the agency- structure relationship. It aims to understand what the strength areas covered in the text is. Additionally, weaker sections are also given consideration. Thus, the report here discusses about various aspects of relationship that exists between agency and structure. The notion of duality by the author is considered too, with due focus on the book Constitution of Society, by Giddens. The notion of studies done to relate the two terms is also covered within the scope of this report. Furthermore, the researchers involved to explore the term are also discussed hereon. This helps in understanding the extent to which both the terms are integrated in this society. These all have helped to reach to certain outcomes of the report at the end. Discussion Agency and structure have been termed as indispensible parts in the social context. These terms are required to relate at one or the other instance. Agency is termed as the capability of individuals to generate wide variety of powers in causal term, while the structure is the set of rules and regulations existing within the society (Frohlich et al., 2001). The relationship between these two instances is yet to explore. Some of the researchers stand in the point, that the two terms inter- relate in themselves, while others consider these as different terms. There does not exist, any discussion of relationship between structure and agency in real terms (Macintyre, 1997; Frohlich et al., 2002) according to some of the researchers. While others state that, these structure and agency are considered as co- dependent and recursive in nature (Nussbaum and Sen, 1993; Sen, 1992). This clearly demonstrates how conflicting the terms are in social context. There is no generalized thought in this arena, instead complete satisfaction and dissatisfaction is noted for the question at hand. This needs to be further explored to understand the concepts associated with the terms. There are different contexts, which integrates the agency and structure. Structural forces are the main determinants for the relationship between agency and structure (Williams, 2003). Thus, the structural forces shall be considered in discussion to understand the concept associated with the terms. This might also help in exploring the text by Giddens in a better manner. Although, in his writings, the discussion of structural forces is missed, he has attempted to use time and geography as basic parameters in his studies. There are number of authors who studied about the relationship of agency and structure (Musolf, 2003; Callinicos, 2004), however the work done by Giddens is important to note in his books such as Constitution of the Society (1986). Most of the writers believed that agency and structure are different terms; however, Giddens consider them as similar. Giddens consider these two as different ways to look one thing. Researchers contribute to routine activities, i.e. those that take place in a similar manner for continuation. Routine activities are considered as social for the organization, as these activities occur in regular fashion. This regular fashion further becomes the set of rules for the society. These rules act as the social orders for an organization. Giddens also consider that time and space results into organizing us in a better manner. Time and place are being considered as important aspects not only for the agency but also for the structure of society. The author considers the time as an aspect, which affects the routine practices. Proper time management is helpful in attaining good routine activities. Thus, author lays focus on right use of time to obtain maximum outcomes. In case one wishes to generate results, there is the need to perform with dual nature. The collaborated approach of using structure and agency is required at such instances. This would entail proper use of time management technique to minimize the wastage of social time. The author thus lays importance on the time. Time is the aspect that demonstrates routine activities. Time is an indispensible part for ones life. He considers people to utilize properly the daily schedule, to make optimal use of time. In case one does not use time in a proper manner, it mi ght result in losses of ones routine plan. Giddens also discussed about the consequences attached with improper use of time management. In case, one does not use the time in a proper manner, it affects the routine activities of an individual. However, if one wishes to work on his knowledge, he can act well in this arena. This affects the agency structure by the mismatch that generates due to lack of control on structure concerned of an entity. For the society to develop with its full potential, it shall discuss the relation between structure and agency (Hay and Wincott, 1998). This shall not be ignored. Giddens had worked to elaborate the point further. However, his writings were not able to describe clearly the point due to lack of clarity in his thought process. His attempt to contribute to agency structure relationship was though worth noting, but for a new reader, it becomes a point of confusion. Giddens, in his book named as Constitution of Society, had not given any clear definition of the terms considered in his writings. The content seems tough to be understood by a reader who has not gone through the previous writings of the author. Thus, it necessitates the basic concept to be clarified, before going through the book. The relation between agency and structure is always at perennial (6). It is not a one-time process. The author thus attempted to describe the relationship considering the time-geography too. This was in line with the time management of the author. This demonstrates the importance of time, and its relation to the geographic unit. The ways geographical parameters change with time are also discussed. Additionally, the variation of structure and agency with different time and geographic locations is considered in the study as well. This relationship between agency and structure is also well studied by researchers such as Rothstein and Hall (1993), Thelen, and Steinmo (1992). This is the reason, many researchers attempted to explore the relationship. However, the complexity associated with them in social context has acted as a hurdle to describe the two characteristics. Giddens further followed the tradition in his writings. He was unable to thoroughly explore the relationship between the two terms. The agency and structure were not thoroughly discussed in his writings. The discussion on duality of these terms was there though; the basic concepts associated with them were not described. Thus, on looking other side of the coin, we can see that the book of Giddens lacks in clearly describing the duality and social practice concept. It does not describe the ways in which practices are constituted, the way in which it relates social system etc. The book also misses practice concept, which is important to attain sust ainable analysis. Thus, the book is tough to understand for someone, who has not read previous books of the author. It directly summarizes the duality structure for understanding the agency- structure relationship. This way, he created a sort of confusion situation in the minds of readers who have not read his previous writings. For an individual to understand the text by Giddens it becomes mandatory to understand the basic concepts associated with the topic; else, it would become tough for them to understand the discussion done in his writings. The authors lacks in discussing the reason, why people want certain things. It just discusses the wants of people. The subject here is constituted in a social manner. There is also the discussion laid that wants arise from the needs, which are related to ontological security. The theory discusses the way individuals can achieve proper results using the agents. Thus, the concept of agency- structure relationship has always been a tough task. It is with not only Giddens, but also the researchers such as Dahlgren and Whitehead (1991) had failed to establish a relationship between these two characteristics of society in the daily life of the world. There is thus the need to understand the basic concepts in hand. The social context, with reference to time is to be understood at initial stages. This would help in creating a framework for the point at hand, and the integration of these two characteristics of society will be done in a better manner. The research in todays life is exploring further the structure and relationship and the behavioural pattern (Williams, 1995). These further explorations are expected to help the society in analyzing these duality and routine practices in the right manner. There would be lack of clarity, and the outcomes will be with a stronger research background. Thus, the main point of confusion exists to know the re lationship between structure and agency (Gerhardt, 1979), which if explored by the researchers, can lead to attain certain outcomes, which would help us in further understanding the concept at hand. This would entail the need to use proper time management techniques. The weak background of Giddens shall not be over- focused, but shall be given an opportunity of further exploration using the basic concepts at hand, to reach to the outcomes. This would help us to attain the results at a greater pace, and with clear outcomes, which does not have conflicting situations, as at present. Conclusion On considering the notion of duality and the social practice of relationship between agency and structure, we have come up with some important findings. We can interpret that the writings of Giddens are quite conflicting at certain instances. These act as the constraining and enabling at the same time. At certain instances, Giddens talk about the practical aspect of life. He considers time as real and factual to work out on the life. However, at other instances assumptions are encouraged by the author. This raises the problem of lack of clarity in his thought process. Additionally, the complexity involved with the writings of Giddens, enforce one to go through the basic concepts, prior to reading the text under review. Thus, there was a mixed approach obtained. At some instances, it was noted that the structure and agency are well integrated with each other, while at others there was noted the lack of control and dependency of one characteristic on the other. This mixed approach has resulted in further elaboration of the associated concepts, which would help in understanding the point. Else, it would be tough to understand this text in hand, with lack of control over the text and lack of clarity by the author. The basic concepts can however be of great help in understanding the concept at hand, and the associated relationship. Thus, overall the text was a good collection of data, but lacks clarity and mandates the reader to go through basic concepts, prior to going through the text at hand. This way, one would be able to understand the associated characteristics in a better manner.

How to Be a Porn Star

We might all watch porn, but wanting to star in it is a different story — for some of us at least. While the majority of the porn-watching population would rather keep their â€Å"sexploits† hidden between the sheets, there are the rare few who want to share their unclothed talents with the world. And this fantasy isn’t so hard to achieve, thanks to the advice of porn stars Ashlynn Brooke and Shane Diesel who tell all you aspiring â€Å"performers† everything you need to know about how to audition for a porn and get your foot (amongst other things) in the door. AppearanceWhat kind of shape do you have to be in to audition for porn? Ashlynn: Fortunately, being that sex is the most natural thing in the world and everyone enjoys it, this also means that people are naturally attracted to all different body shapes, sizes, etc. I think as long as you love your body and take care of yourself, there's a certain amount of confidence and sexuality that shows through , and that will set you up for success. Be confident in your own skin! Shane: For a male it's better to be fit, athletic and well-groomed; if you look like you're fit, you most likely exercise.This carries over into your performance as far as endurance and stamina go; you don't have to look like a bodybuilder, you just need to posses a nice, fit package no matter what age you are. Performance Are you expected to perform on the spot when you audition for a porn? If so, are you expected to demonstrate the stamina/skills of a seasoned performer? Ashlynn: Yes, you’re expected to put forth a performance. Although the sex will be enjoyable, and everyone will have a great time, it isn't â€Å"home sex. † There is a level of professionalism and eroticism needed to make the scene a good one.Shane: Yes! If you have the nerves to try to be in the adult biz, then you should be able to perform like a seasoned vet. Sure, it takes time to learn everything, but you have to remember yo u have a whole crew that's depending on you. Whatever the director orders you to do, try your best to give him or her as much time and open positions as they want in order to have a great scene. Are performance supplements accepted in the industry? Ashlynn: Most of the time, supplements aren't needed. Being that I'm a girl, I definitely never use them.However, there are times when the situation isn't exactly ideal for the performers (i. e. , a scene in the desert that starts at 4 p. m. when the temperature is a smothering 95 degrees†¦ and it’s lasting until 9 p. m. when the temperature has dropped to 40 degrees). To sum it up, they're not very common, but aren't looked down upon. Shane: Supplements — yes, such as yohimbe, vitamin E, amino acids, ginseng, L-arginine, and saw palmetto. That’s a few, but there are many others that work well for other performers.If you are talking about Viagra or Cialis, then that’s something that’s not encouraged on sets, but if you need them, then you take them at your own risk and it's not provided for you. Audition Tips Ron Jeremy told us that a man's only hope of getting past the audition phase is to go with a girl. Is this true? Ashlynn: That is actually true to an extent. It's very helpful if the guy is requested by a girl/girls. It's a really good way for them to learn the way of the set, and it helps if they know the girl, making it a much easier experience for the â€Å"break† into the business.Shane: That’s pretty much true; he is dead-on about that. She's your way in the door and your comfort zone. If she is your girlfriend, then you are more comfortable working with her, plus she knows the right buttons to push to take you over the top and she will help you keep that edge. It looks great walking into any room with a hot chick on your arm. Shane and Ashlynn keep dishing on how to audition for a porn†¦ Next Page >> AskMen's Free Weekly Newsletter VIDEOS YOU MIGH T LIKE Get Six-Pack Abs With No Crunches Ben Wheatley's Tips For Cracking The F†¦ Promoted Put Some Clothes On Tha†¦ Madame NoirePromoted 30 Of The Hottest Female Athlete†¦ Rant Sports < |12| > by Taboola 67 BY ASHLYNN BROOKE & SHANE DIESEL Ashlynn Brooke & Shane Diesel LIFESTYLE CORRESPONDENTS LICENSE THIS ARTICLE Share Email Print RSS Pages: 1 2 GUYS WHO READ THIS ALSO READ Highest Paying Jobs In The U. S. (AskMen) Porno Industry (AskMen) You Need To Relax (AskMen) Promoted How to Make a Career Change Without Starting Over (Levo League) Promoted P&O Cruises' Spectacular Entertainment Both Aboard†¦ (P Cruises) [? ] HAVE YOUR SAY Read more: http://uk. askmen. com/money/how_to_400/436_how_to. html#ixzz2DdGAUGXU

Heat Transfer Radiation Lab Report

Module :Heat Transfer – Free Convection and Radiation Laboratory Date :22nd March 2012 CONTENTS INTRODUCTION3 AIMS & OBJECTIVES3 Objectives3 To investigate Free Convection and Radiation3 Theory3 EXPERIMENT3 Apparatus Used3 Procedure4 RESULTS, CALCULATIONS, OBSERVATIONS & CONCLUSIONS5 Observations During Tests5 Table 15 Table 25 Calculations6 Calculating Power (Watts)6 Calculating Heat Transfer Emissivity (? )6 Emisssivity of a black body6 Calculating Q rad6 Calculating Q rad6 Calculating Q conv7 Equation for Free Convection7 Percentage values calculation7 Absolute Pressure calculation7Graph of Pressure Against Temp Difference8 Conclusions8 Conclusion11 Typical Examples of Heat Transfer12 References13 List of Figures, Tables & Graphs14 Heat Transfer Laboratory Sheet I14 Heat Transfer – Free Convection and Radiation Laboratory INTRODUCTION The purpose of this lab is to understand natural and forced convection on a cylinder by measuring surface and ambient temperatures and relating the data to convection heat transfer equations. AIMS & OBJECTIVES Objectives To investigate Free Convection and Radiation 1. Determine the emissivity (? ) of an element experimentally. . Determine the Heat transfer coefficients by free convection Theory Natural Convection: Heat transfer through circulation of fluid due solely to gravity Forced Convection: Heat transfer through circulation of fluid due to forced fluid movement (fan, pump, etc. ) Radiation: Heat transferred by surface photon emission, typically only significant at T>>Room Temp. EXPERIMENT Apparatus Used Figures 1 below shows the vacuum pump vessel and measuring equipment used The apparatus consisted of a heated element which was suspended inside a [pressure vessel.The air pressure in the vessel was varied by the use of either a bleed valve or a 240v vacuum pump. The heat input to the e element was varied by up to 10W, the max working temp was not to exceed 200 °C and maintained at that temperature or less throughout the experiment. The heat, power Input, the element, vessel temperatures and the air pressure inside the vessel was determined by the instruments provided for the experiment Procedure 1) Using the wall mounted barometer the atmospheric pressure was 1018 mB The gauge gives a reading of gauge pressure (diff between the pressure inside the vessel and pressure outside the vessel)Absolute pressure (P) = pressure gauge reading + atmospheric pressure (mB) 2) Pressure reduced to 2mB and input voltage set to 8. 21 volts. 3) Observations and readings taken after 15 mins to allow system to stabilise and readings tabulated. 4) Item 3 repeated with Vacuum pressure reduced by 12, 60, 200, 500 and then finally with the bleed valve fully open tabulated as before. 5) Bleed valve was then fully opened to allow the pressure inside the vessel to meet atmospheric pressure and readings tabulated. RESULTS, CALCULATIONS, OBSERVATIONS & CONCLUSIONSObservations During Tests The initial observations were of the temperature, vacuum pressure and vessel pressures in relation to the inside diameter of the vessel and element assembly. The Temp Diff verses Abs pressure graph below (Graph 1) shows the temp difference at zero free convection given by the equation for a straight line Y=MX+C Surface area of the vessel was given as 3070mm? , Element Length was given as 152mm and 6. 35mm respectively. The following Tables detail what is actually occurring to temperature and heat transfer inside the vessel.The table below shows the results from the tests carried out, using pressure gauge readings -1015 (mB), -1002(mB), -957 (mB), -815(mB), -515(mB) and 0. |Pressure Gauge |Abs Press |Voltage |Current |Power |Element |Element | |(vacuum) | | | | | | | |TEL –TV (K) |(Mb)^1/4 |W |W |% |% | WM^-2K^-1 | |144 |2^1/4 = 1. 19 |4. 7 |1. 14 |81 |19 |2. 57 WM^-2K^-1 | |133 |16^1/4 = 2 |4. 31 |1. 66 |72 |28 |4. 06 WM^-2K^-1 | |123 |61^1/4 = 2. 79 |3. 81 |2. 13 |64 |36 |5. 64 WM^-2K^-1 | |111 |20 3^1/4 = 3. 77 |3. 25 |2. 71 |55 |45 |7. 95 WM^-2K^-1 | |97 |503^1/4 = 4. 73 |2. 68 |3. 24 |45 |55 |10. 8 WM^-2K^-1 | |87 |1018^1/4 = 3. 22 |2. 27 |3. 65 |38 |62 |13. 66 WM^-2K^-1 | Table 2 Calculations Heat losses in the connecting leads Q = (0. 94 x Volts x Amperes) in watts Calculating Power (Watts) Power = Volts x Amperes (Watts) Power= 8. 21volts x 0. 779 amps = 6. 39 (W) x Heat loses Power = 6. 39 (W) x 0. 94 = 6. 01 Watts Heat Transfer = 0. 94 x 8. 21 x 0. 779 = 6. 01 watts Calculating Heat Transfer Emissivity (? ) Emisssivity of a black body ( copper ) = 1 If ? = >1 Use ? = 0. 7 to calculate Q rad ? = Q rad Joules or Watts A x ? x (T^4 EL – T^4 v) ? = 6. 01(W) = 1. 2 ratio (3070Ãâ€"10^-6 ) x (5. 67Ãâ€"10^-6 ) x (436^4 –292 ^4) Calculating Q rad for Pressure -1015 Mb Q rad = ? x A x ? x (T^4 EL – T^4 v) Q rad = 0. 97 x (3070Ãâ€"10^-6 ) x (5. 67Ãâ€"10^-6 ) x (436^4 –292 ^4) Q rad = 4. 87 Watts Calculating Q rad for Pressure -1002 Mb Q rad = ? x A x ? x (T^4 EL – T^4 v) Q rad = 0. 97 x (3070Ãâ€"10^-6 ) x (5. 67Ãâ€"10^-6 ) x (426^4 –293 ^4)Q rad = 4. 31 Watts Calculating Q conv for Free Convection at Heat input 4. 87(W) Q conv = Heat loss x Volts x Amperes – Q rad Q conv = 0. 94 x 8. 21 x0. 779 – 4. 87 Q conv = 1. 14 Watts Equation for Free Convection Q conv = h ( Convected heat transfer ) x A x (T^4 EL – T^4 v) Transpose for h (Convected Heat Transfer) h = Qconv h = 1. 14 = 2. 58Wm^-2K^-1 A x (T^4 EL – T^4 v) (3070Ãâ€"10^-6 ) x (436^4 – 292) Percentage values calculation Qrad + Qconv = Qtotal 4. 87 + 1. 14 = 6. 01 Watts Qrad% = 4. 87/ 6. 0 x 100% = 81% QRad this is because it was not a perfect vacuum Qconv % =1. 14/ 6. 01 x 100% = 19% QConv this is because it was not a perfect vacuum Absolute Pressure calculation Abs Press = Gauge pressure – Atmos Pressure =1015Mb – 1018Mb = 3^1/4 Graph of Pressure Against Temp Difference [pic] Graph 1 Conclusions Temp differe nce for free convection crosses Y axis is at 160(K) for zero gas pressure, the power by the heater element has transferred completely to the vessel by radiation at his point. Natural convection is more prevalent at lower temperatures whereas radiation is more prevalent at higher temperaturesPossible Sources of error: †¢ conduction from the heated cylinder to its housing tube †¢ possible changes in ambient temperature †¢ Variations in surface temperature Heat Transfer by Convection and uses Heat typically does not flow through liquids and gases by means of conduction. Liquids and gases are fluids; their particles are not fixed in place; they move about the bulk of the sample of matter. The model used for explaining heat transfer through the bulk of liquids and gases involves convection. Convection is the process of heat transfer from one location to the next by the movement of fluids.The moving fluid carries energy with it. The fluid flows from a high temperature locat ion to a low temperature location. [pic] (Images courtesy Peter Lewis and Chris West of Standford's SLAC. ) To understand convection in fluids, Consider the heat transfer through the water that is being heated in a pot on a stove. The source of the heat is the stove burner. The metal pot that holds the water is heated by the stove burner. As the metal becomes hot, it begins to conduct heat to the water. The water at the boundary with the metal pan becomes hot. Fluids expand when heated and become less dense.So as the water at the bottom of the pot becomes hot, its density decreases. The differences in water density between the bottom of the pot, and the top of the pot results in the gradual formation of circulation currents. Hot water begins to rise to the top of the pot displacing the colder water that was originally there. And the colder water that was present at the top of the pot moves towards the bottom of the pot where it is heated and begins to rise. These circulation current s slowly develop over time, providing the pathway for heated water to transfer energy from the bottom of the pot to the surface.Convection also explains how an electric heater placed on the floor of a cold room warms up the air in the room. Air present near the coils of the heater warm up. As the air warms up, it expands, becomes less dense and begins to rise. As the hot air rises, it pushes some of the cold air near the top of the room out of the way. The cold air moves towards the bottom of the room to replace the hot air that has risen. As the colder air approaches the heater at the bottom of the room, it becomes warmed by the heater and begins to rise. Once more, convection currents are slowly formed.Air travels along these pathways, carrying energy with it from the heater throughout the room. Convection is the main method of heat transfer in fluids such as water and air. It is often said that heat rises in these situations. The more appropriate explanation is to say that heated fluid rises. For instance, as the heated air rises from the heater on a floor, it carries more energetic particles with it. As the more energetic particles of the heated air mix with the cooler air near the ceiling, the average kinetic energy of the air near the top of the room increases.This increase in the average kinetic energy corresponds to an increase in temperature. The net result of the rising hot fluid is the transfer of heat from one location to another location. The convection method of heat transfer always involves the transfer of heat by the movement of matter. The two examples of convection discussed here – heating water in a pot and heating air in a room – are examples of natural convection. The driving force of the circulation of fluid is natural – differences in density between two locations as the result of fluid being heated at some source. Some sources introduce the concept of buoyant forces to explain why the heated fluids rise. We will not pursue such explanations here. ) Natural convection is common in nature. The earth's oceans and atmosphere are heated by natural convection. In contrast to natural convection, forced convection involves fluid being forced from one location to another by fans, pumps and other devices. Many home heating systems involve force air heating. Air is heated at a furnace and blown by fans through ductwork and released into rooms at vent locations. This is an example of forced convection.The movement of the fluid from the hot location (near the furnace) to the cool location (the rooms throughout the house) is driven or forced by a fan. Some ovens are forced convection ovens; they have fans that blow heated air from a heat source into the oven. Some fireplaces enhance the heating ability of the fire by blowing heated air from the fireplace unit into the adjacent room. This is another example of forced convection. Heat Transfer by Radiation A final method of heat transfer involves radiation. R adiation is the transfer of heat by means of electromagnetic waves.To radiate means to send out or spread from a central location. Whether it is light, sound, waves, rays, flower petals, wheel spokes or pain, if something radiates then it protrudes or spreads outward from an origin. The transfer of heat by radiation involves the carrying of energy from an origin to the space surrounding it. The energy is carried by electromagnetic waves and does not involve the movement or the interaction of matter. Thermal radiation can occur through matter or through a region of space that is void of matter (i. e. , a vacuum).In fact, the heat received on Earth from the sun is the result of electromagnetic waves traveling through the void of space between the Earth and the sun. All objects radiate energy in the form of electromagnetic waves. The rate at which this energy is released is proportional to the Kelvin temperature (T) raised to the fourth power. Radiation rate = k†¢T4 (Images courte sy Peter Lewis and Chris West of Standford's SLAC. ) The hotter the object, the more it radiates. The sun obviously radiates off more energy than a hot mug of coffee. The temperature also affects the wavelength and frequency of the radiated waves.Objects at typical room temperatures radiate energy as infrared waves. Being invisible to the human eye, we do not see this form of radiation. An infrared camera is capable of detecting such radiation. Perhaps you have seen thermal photographs or videos of the radiation surrounding a person or animal or a hot mug of coffee or the Earth. The energy radiated from an object is usually a collection or range of wavelengths. This is usually referred to as an emission spectrum. As the temperature of an object increases, the wavelengths within the spectra of the emitted radiation also decrease.Hotter objects tend to emit shorter wavelength, higher frequency radiation. The coils of an electric toaster are considerably hotter than room temperature an d emit electromagnetic radiation in the visible spectrum. Fortunately, this provides a convenient warning to its users that the coils are hot. The tungsten filament of an incandescent light bulb emits electromagnetic radiation in the visible (and beyond) range. This radiation not only allows us to see, it also warms the glass bulb that contains the filament. Put your hand near the bulb (without touching it) and you will feel the radiation from the bulb as well.Thermal radiation is a form of heat transfer because the electromagnetic radiation emitted from the source carries energy away from the source to surrounding (or distant) objects. This energy is absorbed by those objects, causing the average kinetic energy of their particles to increase and causing the temperatures to rise. In this sense, energy is transferred from one location to another by means of electromagnetic radiation. The image at the right was taken by a thermal imaging camera. The camera detects the radiation emitte d by objects and represents it by means of a color photograph.The hotter colors represent areas of objects that are emitting thermal radiation at a more intense rate. Conclusion The experiment described above provides a convenient method whereby You may investigate the different processes that contribute to cooling in a standard laboratory experiment. In particular, the measurements obtained to enable you to clarify the relative contributions from convection and radiation. Examples of Free – Natural Convection Heat transfer by natural convection occurs when a fluid is in contact with a surface hotter or colder than itself. As the fluid is heated or cooled it changes its density.This difference in density causes movement in the fluid that has been heated or cooled and causes the heat transfer to continue. There are many examples of natural convection in the food industry. Convection is significant when hot surfaces, such as retorts which may be vertical or horizontal cylinders , are exposed with or without insulation to colder ambient air. It occurs when food is placed inside a chiller or freezer store in which circulation is not assisted by fans. Convection is important when material is placed in ovens without fans and afterwards when the cooked material is removed to cool in air.Convective heat transfer is a mechanism of heat transfer occurring because of bulk motion (observable movement) of fluids. Heat is the entity of interest being advected (carried), and diffused (dispersed). This can be contrasted with radiative heat transfer, the transfer of energy through electromagnetic waves. Heat is transferred by convection in numerous examples of naturally occurring fluid flow, such as: wind, oceanic currents, and movements within the Earth's mantle. Convection is also used in engineering practices to provide desired temperature changes, as in heating of homes, industrial processes, cooling of equipment, etc.The rate of convective heat transfer may be impro ved by the use of a heat sink, often in conjunction with a fan. For instance, a typical computer CPU will have a purpose-made fan to ensure its operating temperature is kept within tolerable limits. Typical Examples of Heat Transfer CONDUCTION: Heat conduction is an essential and commonplace part of our daily lives, in industry, and in nature. Whenever heat needs to be transferred through an opaque substance, the transfer must be by conduction.In a hot-water heating system, for example, heat from burning fuel is transferred by conduction through the iron or steel of the boiler to heat the water. Heat from a burner on a stove is conducted through the bottom of utensils to cook food. In nature, the surface of the earth is heated by the sun, and some of this heat is conducted to deeper layers of the soil during the day and back to the surface at night-the varying ability of different kinds of soil and water to absorb and conduct heat received from the sun has a profound effect on local and worldwide weather and climate. Examples Touching a stove and being burned -Ice cooling down your hand -Boiling water by thrusting a red-hot piece of iron into it CONVECTION: Free, or natural, convection occurs when bulk fluid motion (steams and currents) are caused by buoyancy forces that result from density variations due to variations of temperature in the fluid. Forced convection is a term used when the streams and currents in the fluid are induced by external means—such as fans, stirrers, and pumps—creating an artificially induced convection current. Examples -Hot air rising, cooling, and falling (convection currents An old-fashioned radiator (creates a convection cell in a room by emitting warm air at the top and drawing in cool air at the bottom). RADIATION: – Heat from the sun warming your face- Heat from a lightbulb – Heat from a fire – Heat from anything else which is warmer than its surroundings. – Gas chambers in Jet engines – Circulation Boiler Furnaces Industrial example Radiation Heat transfer generally occurs in Higher temperature applications within processes with furnace temperatures above about 2200 °F (1200 °C). They usually have furnaces which use combustors such as in the metals, minerals, and waste incineration industries.In general, the dominant heat transfer mechanism in those industries is thermal radiation. This is in contrast to lower temperature applications where both radiation and forced convection are often important. References [1] Understanding Physics, sections 11. 5 – 11. 7, John Wiley & Sons 1998. [2] C. T. O’Sullivan, Correction for cooling techniques in heat experiments. Physics Education, 25, 176 – 179 (1990). [3] The data acquisition system (data logger) used was the eProLab system developed under the Leonardo da Vinci Programme ComLab2 (project NO SI 143008); website www. e-prolab. com/comlab/. 4] In some situations differences between Ts and Ta may be important; see, for example, C. T. O’Sullivan, Newton's law of cooling – a critical assessment, Amer. J. Phys. , 58 (10), 956 – 960 (1990). SHEFFIELD HALLAM UNIVERSITY FACULTY OF ACES (2009), Process Engineering Lab Sheet. Multi Hole Extrusion Suranaree University of Technology, Last accessed 7th April 2009 at: http://www. sut. ac. th/Engineering/metal/pdf/metform/04_extrusion. pdf ROYMECH : Mechanical engineering and engineering materials. – Last accessed 1st April 2009 at: http://www. roymech. co. uk/Useful_Tables/Manufacturing/Extruding. tml Russ College of Engineering and Technology at Ohio University. http://www. ent. ohiou. edu/~raub/manufacturing/extrusion. htm#Types%20of%20 extrusion: Course notes and hand outs. Sheffield Hallam University List of Figures, Tables & Graphs Figure 1Vacuum Pump and Vessel set up Table 1Pressure gauge readings -1015 (mB), -1002(mB), -957 (mB), -815(mB), -515(mB) and 0 Table 2Temp Differences of 144(K), 133( K), 123(K), 111(K), 97(K) and 87(K) Graph 1Temp Difference Vs Absolute Pressure Appendixes Heat Transfer Laboratory SheetI [pic] ———————– Figure 1 Table 1 Temp difference free convection (160K)