Saturday, January 25, 2020

Horace Miner’s Body Ritual Among the Nacirema Essay -- Horace Miner Bo

Horace Miner’s Body Ritual Among the Nacirema In Horace Miner’s article, â€Å"Body Ritual Among the Nacirema†, he talks about a tribe and describes their odd behavior. He tells about how the tribe performs these strange daily rituals and how their peculiarity is extreme, but in fact he is actually speaking of Americans as a whole (Miner). Miner uses this style of writing to more effectively prove his point: that Americans are ethnocentric. Miner does an exceptional job in disguising the Nacirema as Americans. Some of the things he disguises are the bathroom, which he says is a cleansing shrine. He disguises the medicine chest as the main device in the shrine, a bundle of hog hairs on a stick as a toothbrush, and magical potions as medicine (Miner). In this article, Miner gives a few hints that the Nairema are indeed Americans. The fact that Nacirema spelled backwards is American is a huge hint by itself. Another clue is the â€Å"holy-mouth-men.† If you sit down and think about it for a second it is obvious to realize that they are indeed dentists. Also the me...

Friday, January 17, 2020

Applied Heat Past Examination Questions

Applied Heat past Examination Questions 1. An Ammonia refrigerator is to produce 2 tonne of ice per day at -4 °C from water at 20 °C. if the temperature range in the compressor is between 25 °C and -6 °C, Calculate horse power required to derive the compressor. Latent Heat of ice = 80 kcal/kg, and specific heat of ice= 0. 5 2. A compressor draws 42. 5 m3 of air per minute in the cylinder, at a pressure of 1. 05 kg/cm abs. It is compressed Polytropically pV1. 3=C to a pressure 4. 2 kg/cm2 abs, before being delivered to a receiver. Assuming a mechanical efficiency of 80% Calculate: a.Indicated horse power; b. Shaft horse power, and c. Overall isothermal efficiency. 3. A single stage impulse turbine has a speed of 1000rpm and a mean blade ring diameter of 60 cm. The nozzles are inclined at 22 ° to the plane of rotation and the specific enthalpy drop is 190 KJ/kg. Determine: a. The relative velocity of the steam at inlet, and b. The blade inlet angle. 4. An engine consumes fuel of calorific value 44MJ/Kg at a rate of 45tonne/day. It the indicated thermal efficiency is 39% and break thermal efficiency is 33%. Calculate: a. The indicated power, b. The brake power, and . The power lost to friction. 5. The air in a ship’s saloon is maintained at 19 °C and is changed twice every hour from the outside atmosphere which is at 7 °C. The saloon is 27m by 15m by 3m high. Calculate the kilowatt loading to heat this air taking the saloon to be at atmospheric Pressure = 1. 013 bar. R for air =0. 287 KJ/kg K. 6. 0. 23kg of air has an initial pressure of 1. 7 MN/m2 and a temperature of 200 °C. it is expanded to a pressure of 0. 34 MN/m2 according to the law pV 1. 35 = Constant. Determine the work transferred during the expansion. Take R = 0. 29 KJ/kg K. 7.The equivalent evaporation of a boiler from and at 100 °C is 10. 4 kg steam/kg fuel. The calorific value of the fuel is 29800KJ/kg. Determine the efficiency of the boiler. If the boiler produces 15000 kg of steam per hour at 24 bar from feed water of 40 °C and the fuel consumption is 1650 kg/h, determine the condition of the steam produced. 8. A single-cylinder, double acting steam engine is 250mm bore by 300mm stroke and runs at 3. 5rev/s, steam is supplied at 1035 KN/m2 and the back pressure is 34 KN/m2 and the diagram factor is 0. 81. Determine the indicated power of the engine. a. If cut off is at 0. 5 stroke, b. If cut off is at 0. 5 stroke. 9. Air enters a nozzle with a pressure of 700 KN/m2 and with a temperature of 180 °C. Exit pressure is 100 KN/m2. The law connecting pressure and specific volume during the expansion in the nozzle is pV1. 3=Constant. Determine the velocity at exit from the nozzle. Take Cp= 1. 006 KJ/kg K and Cv=0. 717 KJ/kg K. 10. A single row, impulse turbine has a mean blade speed of 215 m/s. Nozzle entry angle is at 30 ° to the plane of rotation of the blades. The steam velocity from the nozzles is 550 m/s. There is 15% loss of relative velocity du e to friction across blades.The absolute velocity at the exit is along the axis of the turbine. The steam flow through the turbine is at the rate of 700 kg/h. Determine: a. The inlet and exit angles of the blades, b. The absolute velocity of the steam at exit, c. The power output of the turbine. 11. The high temperature of a Carnot cycle is 400 °C and the cycle has a thermal efficiency of 55%. The volume ration of the isothermal processes is 2 : 8 : 1. Determine for the cycle: a. The low temperature, b. The volume ration of the adiabatic processes, c. The overall thermal efficiency. Take r = 1. 4 12.A diesel engine has a compression ratio of 14:1 and an efficiency ratio of 0. 7 when referred to the air standard efficiency. The fuel consumption is 5. 65 kg/h. Take r=1. 4 and calorific value of the fuel oil is 44500 KJ/kg. Determine the indicated power developed. 13. The analysis of a fuel oil is 85. 5% carbon, 11. 9% hydrogen, 1. 6% oxygen and 1% impurities. Calculate the percentag e of carbon dioxide in the flue gasses, a. When the quantity of air supplied is the minimum for complete combustion, and b. When the excess air over the minimum is : (i) 25% (ii) 50% iii) 75% 14. In an air compressor the air is compressed to the law pVn=constant. The compressor takes in 105 m3/min of air at 1. 0 bar 27 °C. If the pressure ratio is 5 to 1, calculate; a. The index of compression, b. Power absorbed by the compressor. 15. A single acting opposed piston 6 cylinder two stroke engine have mechanical efficiency of 86% when running at 105 rpm with mean effective pressure of 7. 24 bar, produces brake power of 4326 kW. The mass of the top piston with its connecting parts is 25% greater than that of bottom piston and the combined stroke is 2340 mm.If the stroke of piston varies inversely as the masses of the reciprocating parts. Calculate; (i) The stroke of the top and bottom pistons, (ii) The cylinder diameter. 16. The mass analysis of a fuel is 86% carbon, 11. 5% hydrogen a nd 2. 5% oxygen. If for complete combustion 25% excess air is supplied per kg of fuel burnt, calculate: a. The mass of flue gases, b. Volume of air at 1. 0 bar and 15 °C. Take R for air = 0. 287 kJ/kgh. 17. The diameter of an air compressor cylinder is 140 mm, the stroke is 180 mm, and the clearance volume is 77cm. he pressure in the cylinder at the beginning of the stroke is 1. 0 bar and during delivery is constant at 4. 8 bar. Taking the law of compression as pV1. 25=Constant, calculate; the distance moved by the piston during the delivery period and express this as fraction of the stroke. 18. A turbine plant consists of H. P. and L. P. stages and is supplied with steam at 15 bar 300 °C. The steam is expanded in the H. P. and leaves at 2. 5 bar 0. 97 dry. Some of the steam is bled off to the feed heater and remaining passes to L. P. where it is expanded to 0. 15 bar 0. 84 dry.If the same quantity of work transfer takes place in each unit, calculate the amount of steam bled off expressed as percentage of the steam supplied. 19. 7. 08 liters of air at a pressure 1. 79 bar and temperature of 333 °C is expanded according to the law pV 1. 3 = constant and the final pressure 1. 206 bar, calculate: a. Volume at the end of expansion, b. Work transfer from the air and, c. The temperature at the end of expansion. 20. Steam leaves the nozzle and enters the blade wheel of a single stage impulse turbine at a velocity of 840 m/s and at an angle of 20 ° to the plane of rotation.The blade velocity is 350 m/s and the exit angle of the blade is 25 °12’. Due to friction the steam looses 20% of its rotational velocity across the blades, calculate; a. The blade inlet angle and, b. The magnitude and the direction of absolute velocity of steam at exit. 21. In a Freon-12 refrigerating plant, Freon leaves the condenser with a specific enthalpy of 50kJ/kgK. The pressure in the evaporator is 1. 826 bars and the refrigerant leaves the evaporator at this pressure at a r ate of 0. 4 Kg/s and a temperature of 0 °C. Calculate; a. Dryness fraction of Freon at inlet of the evaporator, b.The refrigerating effect per minute. 22. A glass tube of uniform bore is closed at on end and open at the other. It contains air imprisoned by a column of mercury 42. 7 mm long. When the tube is held vertically with close end at the bottom, the length of the air column is 227. 6mm. Taking 1mm of mercury = 133. 5N/m2 and atmospheric pressure = 101. 5 kN/m2. Calculate the length of the air column if the tube is held vertically with the closed end at the top. 23. A single acting gas engine of bore 190 mm and stroke 380 mm has an indicated power of 13 kW when developing brake power of 9 kW there being 125 explosions per minute.The consumption of gas of calorific value 1. 76 MJ/m3 is 6. 8m3/hour. Calculate the mechanical and indicated thermal efficiencies, and the mean effective pressure. 24. A six cylinder, four stroke, internal combustion engine is required to develop a b rake of 176 kW under the following conditions: Speed 200rev/min, brake m. e. p. 8 bars, stroke/bore ratio 1. 25/1. Break specific fuel consumption 0. 262 Kg/KWh. Calculate:- a. The cylinder dimensions, and b. Fuel consumption kg/h 25. Carbon dioxide leaves a refrigeration condenser with a total heat of 156kJ/kg.After throttling it passes through the evaporator from and it leaves with a dryness fraction of 0. 98. At the evaporator pressure the liquid heat is 12kJ/kg and the latent heat is 280kJ/kg. If 13. 8 kg of refrigerant circulates per minute, calculate:- a. The dryness fraction at the inlet to the evaporator, and b. The heat absorbed in the evaporator in 24 hours. 26. Steam is generated from feed water at a temperature of 93. 3 ° C as follows: In plant A the steam generated is 17. 25 bar dry saturated. In plant B the steam generated is 17. 25 bar 0. 9 dry and, In Plant C the steam generated is 17. 5 bar 82 °C super heat. Calculate the percentage change in the consumption usi ng plant A as the base. 27. A hydrocarbon fuel cell is completely burned with 12. 5 percent excess air. Calculate the Volume of air used to burn 1Kg of fuel, measured at 1. 01 bars and 18 °C. Air contains 23 percent oxygen by mass. Atomic mass relationship: Hydrogen=2, Carbon=12, Oxygen=16. 28. An oil engine has a volumetric compression ratio of 13:1. At the commencement of compression the air in the cylinder is at 1 bar and 15. 6 °C. Calculate the temperature and pressure at the end of compression if the index of compression is 1. 8. 29. A single acting air compressor working without clearance has a 220mm bore and 200mm stroke. The suction conditions are 1 bar 27 °C and running speed is 10 rev/sec. if compression is according to the law pV1. 3=Constant and the discharge pressure is 10 bar. Calculate, a. The mass of air compressed per hour, and b. The discharge temperature. 30. Calculate the final temperatures and final total heat of both (a) and (b). a. Water at 65. 6  °C h aving a mass of 45. 36 kg is cooled by placing 4. 536 kg of ice at -8. 9 °C into the water. b. Water at 65. 6 °C having a mass of 54. 1 kg is cooled by addition of 22. 68 kg of water at 26. 7 °C. 31. An impulse steam turbine operates at 50rev/sec. The mean blade tip diameter is 0. 6m. The blade exit angle is 30 ° and the velocity of the steam relative to the blade at blade exit is 300 m/s. Calculate or determine by any other means the kinetic energy of steam leaving the blades per kilogram of steam flow. 32. A perfect gas at 3. 1 bar and 30 °C is compressed according to the law pV1. 3=constant until its temperature increases to 215 °C. Sketch the process on a p-V diagram and calculate: a.The pressure at the end of compression. b. The changes in enthalpy and internal energy per kilogram of gas. 33. In an ideal constant volume cycle the temperature at the beginning of compression is 50 °C. the volumetric compression ratio is 5:1. If the heat supplied during the bible is 930 KJ/Kg of working fluid, calculate: a. The maximum temperature attained on the cycle, b. Work done during the cycle/kg of working fluid, and c. The thermal efficiency of the cycle. Take ?=1. 4 and Cv= 0. 1717 KJ/Kg K. 34. A fuel has a mass analysis of carbon 87 percent, hydrogen 5. percent and remainder ash. The calorific value of carbon and hydrogen are 34MJ/kg and 145 MJ/kg respectively. Calculate for one kilogram of fuel: a. The calorific value, b. The mass of exhaust gas if 35 percent excess air is supplied. When burning fuel, why is excess air used? Air contains 23 percent oxygen by mass Atomic mass relationships: hydrogen=1, oxygen=16, carbon=12. 35. One kilogram of dry saturated steam at 4 bars is contained in a cylinder fitted with a piston. The steam rejects 320 KJ of heat energy at constant pressure is 1. 4 bars. Calculate: a.The condition of the steam on completion of cooling at constant pressure, b. The condition of the steam on completion of cooling at constant volum e, and c. The quantity of heat energy rejected during constant volume cooling. 36. A steam turbine which operates at 50rev/s has a mean blade-ring diameter of 1m at a certain stage. The blades are designed for 50 percent reaction and have the exit and inlet angles at 30 ° and 50 ° respectively. The turbine is supplied with steam at the ratio of 166. 67kg/s and the stage efficiency is 85 percent. Calculate or determine by any other means: a.The power output of the stage, and b. The specific enthalpy drop in the stage. 37. In Ammonia refrigeration plant the refrigerant leaves the condenser at 22 °C as saturated liquid. The evaporator pressure is 2. 077bar and refrigerant leaves the evaporator 0. 98 dry saturated. For a cooling load of 40kW, calculate: a. The rate of circulation of the refrigerant (kg/s), b. The effective swept volume of the compressor (m3) if its speed is 1 rev/s. 38. A copper bar of 75mm diameter, 13m long is heated by a direct current flowing through the bar. The steady electrical input to the bar is 500W.Assuming the bar is well-insulated and neglecting conduction heat losses at the leads, calculate the wires taken for the temperature of the bar to increase from 5 °C to 365 °C. 39. A single stage double acting air compressor deals with 18. 2m3 of air per minute measured at conditions of 1. 61325 bar 15 °C. The condition at the beginning of compression is 0. 965 bar 27 °C and the discharge pressure is 4. 82 bars. The compression is according to the law pV1. 32=constant. If the mechanical efficiency of the compressor is 0. 9 calculate the input power required to drive the compressor. 40.In a steady flow process the working fluid enters and leaves a horizontal system with negligible velocity. The temperature drop from inlet to outlet is 480 °C and the heat losses from the system are 10KJ/kg of fluid. Determine the power output from the system for a fluid flow of 1. 7kg/s. For fluid Cp=900 J/kgK. 41. A four stroke single cylinder engine working on constant volume cycle, develops 7. 5 KW(Brake) at 60 rev/s, the mechanical efficiency being 0. 8. The pressure at the â€Å"beginning of compression† is 0. 97 bar. The engine has a volumetric compression ratio of 7 and the maximum pressure reached in the cycle is 34 bar.If both compression and expansion is according to the law pV1. 38=constant. Calculate: a. The indicated mean effective pressure, and b. The diameter of the cylinder if stroke/bore ratio is 1. 25. 42. A boiler generates steam at 40 bar 400 °C and supplied to a steam turbine at the rate of 14 kg/s. due to frictional and heat losses the steam at the turbine inlet is at 37 bar 350 °C. If the steam velocity leaving the boiler is 30 m/s and the change in the kinetic energy of steam is negligible. Calculate: a. The diameter of the steam supply pipe, and b. The heat loss from the steam supply pipe.

Thursday, January 9, 2020

Analysis Keystone Xl Pipeline - 1423 Words

Isabella Moreno Mr. Lipham Hon Economy, A Block 15 February 2015 Spring Research Paper: Keystone XL Pipeline The Keystone XL pipeline is a proposed expansion of the existing Keystone system, being proposed to transport greater volumes of Canadian oil sands crude to world market. It would transport Canadian crude oil to the U.S. Gulf Coast for refining or export. Trans Canada’s proposed XL pipeline has emerged as a symbolic flashpoint in the complex debate over energy, the environment, and the economy. Pipeline advocates argue that the project will creates tens of thousands of jobs and by increasing the flow of Canadian Oil into the U.S., will lower gasoline prices and strengthen energy security. Pipeline opponents counter that any†¦show more content†¦If market conditions change, the capacity of the pipeline could be increased to 830,000 barrels per day (bpd). The overall pipeline is estimated to cost 7$ billion. The Canadian company, TransCanada, initially proposed the pipeline in 2005 and applied to the State Department for a construction permit in 2008. The State Department has the permitting authority for the project because it crosses an international border, and the secretary of state must determine whether the project is â€Å"in the national interest†Ã¢â‚¬â€a decision that includes economic, environment, national security and foreign policy consequences. In January 2014, the state department released an environmental impact statement concluding that the pipeline was unlikely to significantly increase the rate of carbon pollution in the atmosphere. That analysis kicked off a 90-day review process in which Secretary of State John Kerry requested comment from eight other agencies including E.P.A. and the Commerce Defense and Homeland Security departments. The State department just finished collecting comments from agencies as to whether the project is in the nation’s best interest. Once Secretary of State John Kerry revised the comments, he sent a recommendation to Obama, who make the final decision. On Tuesday February 24, President Obama vetoed legislationShow MoreRelatedAnalysis Of Transcanadas Proposed Keystone Xl Pipeline1342 Words   |  6 PagesIntroduction TransCanada’s proposed Keystone XL pipeline would move oil sands from Canada and shale oil produced in North Dakota and Montana to Nebraska for further delivery to the Gulf Coast where many refineries are located. This pipeline would be 875 miles of 36-inch pipe with the capacity to transport 830,000 barrels per day. Since the pipeline would cross the US border from Canada to the United States, the pipeline requires a Presidential permit from the state department. This decision isRead MoreAnalysis Of Transcanada s Proposal Of The Keystone Xl Pipeline Essay1123 Words   |  5 Pages This paper explores TransCanada’s proposal of the Keystone XL Pipeline. I will analyze the past problems which resulted in its defeat, along with possible solutions for future implementation. The case study is split in to three main parts: the identification of past issues, an examination of action plans and lastly, recommendations for upcoming development. Identification of Issues The Keystone XL Pipeline fight involved large economic and political issues. Some of the major issues included:Read MoreThe Keystone Xl Pipeline Is The Endurance Of Todays Society1734 Words   |  7 Pagesplays a major role in the world’s economy. The Keystone XL Pipeline is a crude oil pipeline that is designed to run from â€Å"Hardisty, Alberta†¦to Steele City, Nebraska,† (About The Project). Citizens of Canada and the United States are debating the development of the pipeline. There are two sides to this issue, to either approve or disapprove the Keystone XL Pipeline, and by researching this topic I will form an opinion. Most of the Keystone pipeline has already been put in place. According to an imageRead MoreState Department Decision On Keystone Xl Pipeline1533 Words   |  7 PagesJosephine Parker, independent analyst Date: October 22, 2015 Subject: State Department decision on Keystone XL Pipeline Introduction: This memorandum addresses how the State Department of the United States should handle the pending application of the Keystone XL Pipeline. The Keystone XL Pipeline is a project under consideration that would provide a 1,664-mile extension to an existing pipeline system built by Canadian company TransCanada. The extension would transport 830,000 barrels of crudeRead MoreThe Keystone Xl Pipeline Is Job Creation1037 Words   |  5 Pagesargument. One argument made my proponents regarding the Keystone XL pipeline is job creation. Proponents argue that the Keystone XL pipeline will create a total of 9,000 direct jobs and 42,000 indirect jobs. However, of these proposed jobs, only 35 permanent jobs are to be created. Proponents defend this small amount of jobs by stating that this clearly show how efficient the Keystone XL pipeline truly is. Opponents to the Keystone XL pipeline argue that this minuscule amount of jobs is simply notRead MoreThe State Of The Keystone Xl Pipeline1606 Word s   |  7 PagesCompany. The pipeline infrastructure in place known as the Keystone Pipeline would now feature a larger section, which would be known as the Keystone XL. Many arguments to be analyzed involving economics, environmental and safety have been generated for and against this proposed Keystone XL construction. When analyzing the impacts of the building of the Keystone XL pipeline it can be seen it will impact our means of energy supplies. One way the United States would be helped is the Keystone XL pipelineRead MoreThe Keystone Xl Pipeline Project Essay1294 Words   |  6 PagesBuild? The Keystone XL Pipeline Project has many pros and cons just as any project does, but this project has way bigger cons than most projects this country will face today. â€Å"The Keystone XL Pipeline is an environmental crime in progress.† â€Å"It’s also been called the most destructive project on the planet.† The major issues with the Keystone XL Pipeline are â€Å"the dirty tar sands oil, the water waste, indigenous populations, refining tar sands oil and don’t forget the inevitable; pipeline spills.† AndRead MoreThe Controversial Issue of the Keystone XL Pipeline1090 Words   |  4 PagesThe Keystone XL Pipeline has been a major controversial issue in the news lately regarding the expansion of a pipeline from Alberta, Canada to the Gulf of Mexico. This pipeline will cross six states including Montana, Nebraska, Kansas, Oklahoma, South Dakota, and Texas. This pipeline will transport 830,000 barrels of crude tar sands oil to the United States. D espite the immediately benefits for the economy with the installation, the decision is to decline the Keystone XL Pipeline proposal. ThisRead MorePlanning For The Future : The Keystone Xl Pipeline2058 Words   |  9 PagesThe Keystone XL Pipeline Mahatma Gandhi once said, â€Å"Earth provides enough to satisfy every man s needs, but not every man s greed† (Lindley). Even today, people in this world still desire many things much more than they actually need. Several occasions people have failed to take the time and think about the consequences their greeds would have on society. Since 2010, Canada and the United States have built a pipeline that travels through both countries. This pipeline, known as the Keystone PipelineRead MoreThe Alberta Tar Sands: Factors Affecting Extraction and Production of Fossil Fuels1290 Words   |  5 Pagesreserves of fossil fuels, the extraction of these resources is known to cause a variety of social and ecological problems. The extraction process itself is inefficient and the pipeline that has been proposed is subject to many environmental risks. Portions of the pipeline have already been approved and the construction of the pipeline is already begun in some areas. This paper will look at some of the factors associated with tar sands extraction and production of fossil fuels. Introduction Bituminous