Criminal justice Essay Example | Topics and Well Written Essays - 1250 words - 2

Criminal justice - Essay Example As an account to the shaking history of humanitarian catastrophes as well as undoubtedly horrifying awakening to the 20th century in the face of the events leading to World’s FIRST WORDL WAR and the events following it, this article will look into the region most recently in headlines for its problems coming undisturbed straight from the time of start of the century, the BALKANS. The rest of the article also discusses the phenomenon that has now deeply rooted itself in the labyrinths of our minds as an everlasting memory which is being refreshed time and again by the terrorists. We will also look into the impact of the fall of soviet unionand its effect on global terrorism.Balkans is the transit of civilization. It is seen as a connection between three great cultures, the Asian, European and the African culture. And when we have such a strategic and delicate place to be living in, there are bound to be some rifts and discontent among the people who don’t recognize themselves with respect to the region of their birth. Anything can happen right from local interests up to the global interests fighting for the domination over the whole area. And whenever we have wars resulting from the rift, we have political fragmentation and making more states. The initial ottoman empire that was thrown out of the power by the mutual wars that the surrounding countries exercised upon it could not stand up from there and was thrown out along with its rich and ancient culture (along with its historical domination with respect to culture, people and the heir). ... Separation , cruelty and hatred between small ethnic groups developed end of 18th and 19th century because that was the time when the European power: the balance between Russian and Turkish powers was very important and the small Balkan nation demanding its own authority was not given a thought and expectations from Europe to decide upon some conclusion was depressing. The Balkan word is of Turkish origin meaning rocky mountains and this area consists of five states namely Albania, Yugoslavia, Bulgaria, Greece, Romania. The geographical condition Criminal justice 4 of Balkans divides the east from the west Europe. The Balkans is under equipped in terms of communication it is cut off from Adriatic coast, lacks fertile land and the people of the area are separated and there is a tendency towards social isolation and further complimented by divergent temperatures. The Balkan region is primarily dependent on agriculture and the industrialization is on a very small scale, and there is a scarce rainfall and larger density of population lives on cultivable land, which is very less. There is wide variety of languages, religions and races that contribute to political divisions and social schisms and historical events have resulted in perpetual minority problems. Due to this varied pedigree of people there was tension and rivalry among them but even after the balkan wars of 1912-1913, the concluding WWI peace treaties around 6 million people were under the permanent ethnic minority groups and these were the sources of tension and rivalries. Poor economic conditions have usually led to political instability, power politics and dictatorial regimes.[1] TERRORISM IN BALKANS Terrorism and the Balkan

SLP - 1 ADDING VALUE TO THE ORGANIZATION Essay Example | Topics and Well Written Essays - 500 words

SLP - 1 ADDING VALUE TO THE ORGANIZATION - Essay Example To Wegmans Food Market, Inc., its workers are the most significant people followed by its clients. Many organizations put it the other way, where their clients come first and then its employees, but not Wegmans Food Market, Inc. In Wegmans Food Market, workers are considered as an asset to improve efficiency of their social responsibility approach. HR policies, together with its practices, are always connected to the strategic organizational goals. The organizational practices and policies should, at all times, be aimed at improving the individual performance every worker (Becton & Schraeder, 2009). HR should make sure that workers are treated equitably and fairy. Practices and policies in an organization influence how workers relate and interact with one another (Becton & Schraeder, 2009). For instance, in Wegmans Food Market, Inc., the organization typically employees part time workers without any intention of shifting their condition to full time workers, which can significantly cause a huge employee turnover (CNN Money, 2011). HR strategies are the methods by which the organization’s human resource specific tasks are executed (Wilton, 2010). There are â€Å"HR function strategy† and â€Å"people strategy† in any organization that has HR strategies. People strategy applies the relationship of the HR policies, as well as the overall realization of the organizational objectives. According to Becton & Schraeder (2009), functional strategy arises in a situation where the policies HRM are applied for the attainment of departmental goals, as well as the effective management of the workers in the organization. Wilton (2010) argues that there is hard HRM strategy, as well, whereby the workers are considered the same as any other significant resource in an organization or even soft HRM strategy in which every worker is treated as a special resource. All this strategies can be seen in Wegmans Food Market’s HR strategy. However, in

Factors that affect the price elasticity of supply

Factors that affect the price elasticity of supply Price elasticity of supply is a useful concept when we consider supply. It is also use to measure the responsiveness supply to a change in price when we are supplying a good. Below is the formula that use to calculate the price elasticity of supply. Price elasticity of supply (PES) = % change in quantity supplied % change in price There are a few factors that affect the price elasticity of supply. The first factor that affects the determinants of price elasticity of supply is the number of producers. If there are a lot of producers, the easier for the industry to increase the output and cause the price increase. For example, according to the law of supply, the price of a good increase, the quantity supplied of the good increase. Thats why when there are a lot of producers, more goods will be produced and caused the price increase. Besides that, another factor that affects the price elasticity of supply is the time factor. Long run is usually more elastic for supply compare with short run. For example, in the long run period the industry can invest more equipment and build more factories. In addition, they can even enter a new market and start a bigger business. However, in the short run, industry cant extend their factory to produce more goods. Besides that, the prices of the goods are not responsive to the price. Therefore, supply is more elastic in the long run. Part B Businesses always use the concept price elasticity to decide on their pricing strategy. The strategy that used by the businesses to decide their price is price elasticity of demand (PED). Price elasticity of demand can be define as the measurement of the rate of response of quantity demanded due to a price change. There is a formula that uses to calculate the price elasticity of demand. The formula is shown in the figure below. The percentage change in price The percentage change in quantity demanded PED = There are many degrees that show in price elasticity of demand. Price elasticity of demand will normally be a negative relationship between quantity demanded. To determine the degree of PED, ignore the negative sign. The first degree that shows in PED is inelastic demand. This is a degree that show the percentage change in quantity demanded is less than the percentage change in price. For example, 20% decrease in price cause a 10% increase in quantity demanded. The value is less than 1 but greater than 0 (0

Comparing Saint Augustine and Charles Taylors Ideas of Authenticity Es

Comparing Saint Augustine and Charles Taylor's Ideas of Authenticity The notion of authenticity is one of self-fulfillment and Charles Taylor recognizes that there are dangers in accepting modernity’s drive toward self-realization. However, he is not willing to give up on this idea of â€Å"authenticity.† In The Ethics of Authenticity, Taylor lays out a system of thought and morals that connect our search for self-realization with our desire towards self-creation. He is attempting to keep a form of individualism while still operating under objectivism. He will point out the good and damaging aspects of the modern development of an authentic self and mention the importance of some moral measurement system. Taylor claims that St. Augustine initiated a concept of inwardness, a turning towards the inner self to find truth and the idea of authenticity is simply a further development of Augustine’s inwardness. In this paper I will discuss in detail Taylor’s idea of authenticity: the pros and cons. I will lay out some of his arguments as to why he thinks this idea originated with Augustine. I will talk about Augustine’s view on the inner man and how this is connected with knowledge and memory. I will then talk about some of Augustine’s views. Freedom is also an important aspect to moral conduct so I will explore both Taylor’s and Augustine’s view of freedom. Finally, I will argue that the ideal of authenticity (although it contains some truth) is not an ideal that Augustine would promote. Three Modern Worries Taylor begins the book by discussing three worries of modern society. The first is individualism which is selfish and self-centered. The modern concept is bothersome because people see freedom as loosening the chains of traditional notions of hierarchy. We have become a society where we are breaking away from â€Å"older moral horizons.† Everything in creation is connected in some way and when there is a loose hierarchy there follows a loose meaning of life. The â€Å"dark side of individualism† the focuses on the self in such a way that it flattens and narrows the framework which give significance and meaning to human life. The second trouble is the dominant attention given to instrumental reason. Instrumental reason values efficiency above all other goods. Nothing else is considered sacred or has intrinsic value, only extrinsic value. The question is how usef... ...y for us humans. I think it is, but only to the extent that we open ourselves to God, which means in fact, overstepping the limits set in theory by exclusive humanisms. Taylor’s idea of authenticity does give way to many warnings. It is analogous to walking a tight rope. If one leans too much to one side (which in all reality may not be much at all) it can lead to disaster. He adopts a lot from the Romantics and the focus is too much on the individual. Although he does try to get away from too much emphasis on the individual by mentioning the â€Å"horizons of significance† he still does not give us an idea of what this hierarchy consists. People may look inside themselves to formulate this hierarchy but this again can lead to subjectivism. It seems to suggest that there could be a variety of heirachies and who is to say that one is better than the other. Also the ambiguity of his idea of freedom only leads to more ambiguity on his idea of authenticity. These are all problems that Taylor must address if one is to get a clearer concept of his project. If Saint Augustine were to read Taylor I think he would find these worries and suggest that Taylor’s central focus should be on God.

Terrorism: An Illegal Undertaking

THESIS STATEMENT:How do terrorists able to fight governments while having no own operation bases and escape taxable economic entities? Terrorism are applied time and again as affairs of state tags of the morally wrong, haphazard, or intolerable practice of aggression or hazard of ferocity by particular perpetrators as for their specific purposes. Social change is their ultimate goal and this collective revolution is aspired so appallingly that terrorists may execute vastly unswerving crimes, especially for spiritual principles, that they may prefer their own death or the deaths of innocent civilians to attain their objective. Those regarded as terrorists hardly ever distinguish themselves as such, and normally make use of other general names or terms particular to their situation (Hans, 2002).The focal predicament with terrorism is that terrorists do not admit that they are terrorists and asserts that the governments are the terrorists. Despite the fact that an autonomous state adopt ing social freedom may maintain an implication of privileged ethical position than other administration systems, a performance of terror campaign within such a nation may bring about an apparent problem on whether to uphold its civic liberation and as a consequence run the risk of being recognized as pointless in dealing with the dilemma, or otherwise constrain its communal emancipation and hence risk unjustifiable allegation of sustaining a democratic organization.With this information at hand, it is indeed difficult to fight terrorism since they are usually not well organized or located. They don’t have their own operations bases since they are hiding and do not want to be caught or captured. Terrorism can be carried out by covert individuals, assemblages, or federations, funded by certain organizations, with mysterious orderly strategies and assaults in public places. Interaction may come about via prevailing telecommunications or all the way through conventional means suc h as couriers. Additionally, since revolutionaries who are involved in intimidation are not well organized and are considered to be illegal, they are not taxable and will hardly be taxable.Speaking of illegitimacy, several authorized government characterizations of terrorism put in a condition of unlawfulness to differentiate between proceedings that are certified by bylaws and those of other persons and minor units. Using this decisive factor, events that would otherwise be eligible of terrorism would not be taken into account as terrorism if they were approved by the board. For instance, a terrorist attack in a municipality, which is intended to distress national reinforcement for a basis, would not be regarded as terrorism if it were allowed by a reasonable authority (Cronin, 2003).Shared ideologies among permissible meanings of terrorism offer a rising consensus as to denotation and also promote collaboration between regulation enforcement staff in discrete nation states. Among these delineations, there are quite a few that do not make out the likelihood of   acceptable custom of fierceness   by civilians against an assailant in a dominated nation and would categorize all opposition engagements as terrorist parties. Others create a peculiarity between legally recognized and prohibited exploitation of ferocity. Sanctioned classifications ascertain counter-terrorism documents and are usually made available to act it. Most authority descriptions give a rough idea about the subsequent vital standards such as target, purpose, intention, executor, and authenticity of the feat.Groups carrying out viciousness are also frequently identifiable by a following set of executors. Oftentimes the word terrorism and radicalism are employed as exchangeable. Nevertheless, there is a noteworthy dissimilarity between the two as terrorism is basically a threat or a deed of substantial fierceness, whereas radicalism entails the use of non-physical mechanisms to activate peop le’s attention to realize some ideological occurrences (Kalyvas, 2004). They should have their own definite distinction as to which must be taxable.References:Hans, Kà ¶chler (2002). Terrorism and the Quest for a Just World Order. Manila Lectures. FSJBook World, ISBN 0-9710791-2-9.Cronin, Audrey Kurth (2003) Behind the Curve: Globalization and International Terrorism. International Security, Vol. 27, No. 3, pp. 40-41.Kalyvas, Stathis (2004) The Paradox of Terrorism in Civil Wars in Journal of Ethics 8:1, p. 137-138.

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)