Significance of the lifting Dont Ask Dont Tell Policy

Introduction On September 20, 2011, the official policy that outlawed open declaration of one’s sexuality by US homosexual military personnel was lifted by the United States authorities.Advertising We will write a custom research paper sample on Significance of the lifting Don’t Ask Don’t Tell Policy specifically for you for only $16.05 $11/page Learn More The don’t ask, don’t tell (DADT) policy adopted on December 21, 1993, prohibited the country’s military force from acting unfairly against closeted service members or recruits that are not straight, while disqualifying self confession of gay, lesbian, or bisexual individuals in the service.  The reservations came to be, following the enactment of the United States federal law, almost two decades ago. Further, the policy barred individuals who exhibit behaviors that give the impression of engaging in same sex relationships from the military, because tolerating them could water down the effectiveness of the force (O’Keefe, 2011). But the elimination of DADT is expected to affect the reception of the homosexual community in the country’s armed forces. The paper explores the general implications of lifting the DADT policy in the United States. Johnson (2011) believes the US congress passed a bill aimed at upholding DADT, during its late 2010 sittings with the aim of seeking an assurance from the head of state, his defense Secretary, and the highest ranking military officials to the effect that the annulment of the policy would not impair the effectiveness of the country’s military personnel. Further, the bill also provided for two-month period within which the assessment of the situation would be carried out. On July 6, 2011, a federal jury stopped further implementation of the military’s reservations on self confessed or known homosexual soldiers. The end to DADT policy, adopted by the former president Bill Clin ton administration, was on the verge collapse on July 22 2011, when President Barack Obama, Admiral Mike Mullen who is the chairman of the Joint Chiefs of Staff, and Secretary of Defense Leon Panetta officially asked Congress to reconsider its stance (O’Keefe, 2011).Advertising Looking for research paper on government? Let's see if we can help you! Get your first paper with 15% OFF Learn More Whereas some Americans still believe the policy was prematurely terminated, others especially the gay soldiers breathed a sigh of relief terming the development long overdue. President Obama expects more votes from the gay community to improve his reelection bid after his reported concern for the sexual rights of the minority group. One month since DADT was lifted, several military personnel have openly declared on different occasions that they are homosexual (Thompson, 2011). Despite the reprieve, gay rights advocates and military chiefs did not expect a big percentage of soldiers to come out openly about their sexuality, rather they predicted that majority will silently approach colleagues, senior officers, households and pals previously oblivious of their behavior. It is notable, though; that the latest freedom in military recruiting grounds will be of less concern in terms of the sexuality of the new recruits (Dao, 2011). Other Western states could also tolerate homosexual military officers in future. Conclusion Generally, the lifting of the DADT policy in September 2011 motivated gay military officers, who had previously kept their sexuality secret to openly come out and declare their real self. The revocation of the policy immediately triggered more campaigns by gay activists, who are of late openly dishing out free gay literature in military camps. The magazines contain fine details of gay soldiers. Publishers indicate that the military officers whose particulars are captured in the publications volunteered their respective details, adding that they were full aware that no punitive measure would be targeted at them for their condition. Provocative and private, literature offering details of how a number of military officers attempted daily, to exercise their patriotism by dedicating their energies to the defense of their nation and suppressing individual burning desire to enter into homosexual relationships. References Dao, J. (2011/09/19). Don’t Ask, Don’t Tell Ends This Week With Celebrations, Revelations and Questions. New York Times. Retrieved from https://atwar.blogs.nytimes.com/2011/09/19/dont-ask-dont-tell-ends-this-week-with-celebrations-revelations-and-questions/Advertising We will write a custom research paper sample on Significance of the lifting Don’t Ask Don’t Tell Policy specifically for you for only $16.05 $11/page Learn More Johnson, K.B. (2011). Goodbye to All That. Time, 178(13), 34-35. O’Keefe, E. (2011/09/30). Gay weddings can be performe d by military chaplains, Pentagon says. Washington Post. Retrieved from https://www.washingtonpost.com/blogs/federal-eye/post/gay-weddings-can-be-performed-by-military-chaplains-pentagon-says/2011/09/30/gIQA0hX19K_blog.html Thompson, M. (2011). Aye, Aye: Heeding Congress, Navy Reverses Course. Time, 177(21), 14. This research paper on Significance of the lifting Don’t Ask Don’t Tell Policy was written and submitted by user Amphibian to help you with your own studies. You are free to use it for research and reference purposes in order to write your own paper; however, you must cite it accordingly. You can donate your paper here.

Free Essays on The Incredible Journey

Character description Tao, a Siamese cat, is relatively timid. A â€Å"scardy cat† if you will. During this journey of a lifetime, Tao is a scared, dependant, whiny, boring character! During the journey across the wilderness Tao gets scared and is comforted by Bodger. I think she complains way too much, she is afraid of every thing, and she has no use! But then again, no cats have a use. Bodger, an English Bull Terrier, is brave, most of the time, but still kind of stupid too! He makes stupid moves and gets in trouble more than once and gets him self hurt just as many times! He’s kind of like Roger from â€Å"Sister Sister†. I think he would be a good dog to have but not as good as my dogs! Then Luath, the Labrador retriever, is a courageous, kind, wise, old dog, which is very loving and understanding. I think he’s kind of like Shawn Connery in the James Bond, 007 movies! During their journey, when Tao becomes scared Luath takes it upon himself to comfort her. Luath leads Tao and Bodger through the Canadian wilderness to find their family successfully. Summary The story begins with three pets named Tao, whom is a Siamese cat, Bodger whom is an English Bull Terrier and Luath whom is a Labrador retriever. They live in Ontario, Canada with their family. The three pets are dropped off at a farm because their family is going on a trip for vacation, to Los Angeles, even though it’s just for the weekend, the pets still very are worried. They think that their family is leaving them. Luath, the take-charge kind-of dog, leads Tao and Bodger on a journey of a lifetime, over 250 miles across the Canadian wilderness, in order to get home to their vacationing family. They go over mountainous hills, canyon like rivers and even fight vicious, wild beast like dogs. The animals had to spend the night out in the wide-open Canadian fields. Tao, of course, was scared of the noises that the wild animals made and so Luath courageously slept wi... Free Essays on The Incredible Journey Free Essays on The Incredible Journey Character description Tao, a Siamese cat, is relatively timid. A â€Å"scardy cat† if you will. During this journey of a lifetime, Tao is a scared, dependant, whiny, boring character! During the journey across the wilderness Tao gets scared and is comforted by Bodger. I think she complains way too much, she is afraid of every thing, and she has no use! But then again, no cats have a use. Bodger, an English Bull Terrier, is brave, most of the time, but still kind of stupid too! He makes stupid moves and gets in trouble more than once and gets him self hurt just as many times! He’s kind of like Roger from â€Å"Sister Sister†. I think he would be a good dog to have but not as good as my dogs! Then Luath, the Labrador retriever, is a courageous, kind, wise, old dog, which is very loving and understanding. I think he’s kind of like Shawn Connery in the James Bond, 007 movies! During their journey, when Tao becomes scared Luath takes it upon himself to comfort her. Luath leads Tao and Bodger through the Canadian wilderness to find their family successfully. Summary The story begins with three pets named Tao, whom is a Siamese cat, Bodger whom is an English Bull Terrier and Luath whom is a Labrador retriever. They live in Ontario, Canada with their family. The three pets are dropped off at a farm because their family is going on a trip for vacation, to Los Angeles, even though it’s just for the weekend, the pets still very are worried. They think that their family is leaving them. Luath, the take-charge kind-of dog, leads Tao and Bodger on a journey of a lifetime, over 250 miles across the Canadian wilderness, in order to get home to their vacationing family. They go over mountainous hills, canyon like rivers and even fight vicious, wild beast like dogs. The animals had to spend the night out in the wide-open Canadian fields. Tao, of course, was scared of the noises that the wild animals made and so Luath courageously slept wi...

Lab report (Should we mine this ore) Example | Topics and Well Written Essays - 750 words

(Should we mine this ore) - Lab Report Example The experiment results proved that absorbance is proportional to the concentration. In relation to these, the experiment is related to Beer-Lambert Law which is the Beer-Lambert Law (A= Æ bC) is a combination of molar absorptive (e), sample concentration(C), solution thickness (b), absorbance (A). In this experiment, a standard curve was applied to determine and express the relationship between two quantities. In this case, the essay data is plotted to determine the concentration of the given substance .The Beer-Lambert Law can prove that the solution’s concentration is directly proportional to the solution’s absorbance. The Beer-Lambert Law is expressed as below: Furthermore, Absorbance= -log (%T) +2 is as well referred to as Beer’s Law. Percent transmittance and absorbance on the other hand was as well considered in this experiment. Absorbance represents the logarithmic measure of the level of light absorbed at a given wavelength as light passes through the solution. Furthermore, matter and light interaction also enabled us to further understand the basics of the lab experiment. Through Louis de Broglie theory and quantum physics, it is noted that matter and light interact through transmission, emission, reflection and absorption. Through data collection from multiple experiment trails, it can be employed to determine the percent transmittance. By definition, the percent transmittance is the intensities ratio of light through a medium to the initial light intensity. It can as well be employed to determine the relationship between the wavelengths and intensity passing through the solution. Percent transmittance is expressed as below: To determine the best acid to use from the analysis of the provided acid with the ore, firstly, 6M of the 3 acids and 3M of one acid were used to make 4 solutions with Cu (NO3)2.3H2O.In this case, 3M and 6M represented very strong acid concentration. The Cu(NO3)2.3H2O amount used that

Against the patenting genes Essay Example | Topics and Well Written Essays - 250 words

Against the patenting genes - Essay Example This is essential for assessing the predisposition of the patients to cancer. Legalization of gene patents is regressive not only to the medical research but also to the independence and growth of research centers or countries other than the one to which patent protection has been provided. It is, indeed, sad, that â€Å"some genetic tests can’t be done in Canada because U.S. companies hold patents on the tests and the genes and have threatened legal action if the patents are violated by doing the tests in Canada, rather than the U.S.† (CBC News, 2014). Legalization of gene patents has resulted in patenting of a significant number of genes. There are total 30,000 genes in humans and 8,000 of them have already been patented (Wagner, 2009). This means that the number of genes that can be tested upon for identification of cure for diseases has been reduced significantly. So gene patenting should not be

The impact of the anti-immigration laws that have been introduced by Research Paper

The impact of the anti-immigration laws that have been introduced by Arizona and the participation of Hispanics in the U.S. political system - Research Paper Example The immigration issue has been taking the spotlight in recent decades in America. It has been a lingering concern for Americans who are starting to question the long-held mantra that the United States is the land of almost infinite opportunities. There is a growing fear among the citizenry that such limitless opportunities are no longer the case today or that they no longer are as easy as they were in the past. The US government has actually wavered in terms of addressing the issue head-on. For instance from 1960 to 1970, a major immigration policy reform was enacted with the amendments to the Immigration and Nationality Act of 1952 and afterwards, many thought that it was enough. No significant immigration policy was introduced well until the 1990s. Recent developments, however, are significantly putting pressure on immigration policymaking. The US is considered to have the highest immigration rates globally and that more than a million people legally immigrate to the country annual ly, leading foreign-born citizens to constitute 13 percent of the entire American population. (Bardes, Shelley and Schmidt 2008, p. 482) This figure excludes the immigrants that cross the US border illegally. The former American Ambassador to Mexico, Jeffrey Davidow (2007) summed up the prevailing sentiment: While race race-baiting and violent anti-immigrant sentiment had largely disappeared from the American political vernacular, there was a nagging anxiety about the growing number of foreigners in the United States. Americans were asking, â€Å"Where did all these people come from? (11)† With the current protracted economic downturn, the high and constant flux of the inflation rate, the governments accumulating debt and budget deficits, as well as the high number of job losses, the public is increasingly fearful that immigrants would take away jobs that should have been taken by Americans in the first place. Surveys conducted from 1960s until today demonstrate the increasin g concern of Americans for immigration (Simcox 1997, 129) It is in this respect that the strict anti-immigration policy was enacted by the state of Arizona. This paper will examine the laws enacted by the state against immigration and its impact, particularly in the participation of Hispanics in the American electoral process. Background: The Arizona Anti-Immigration Laws Prior to the enactment of the series of Arizona anti-immigration laws, two significant immigration statutes were enacted in the US: the Immigration Reform and Control Act of 1986 (IRCA) and the Illegal Immigration Reform and Responsibility Act (IIRIRA). Both of these legislations aim to manage immigration with the former focusing on permanent immigrants instead of the temporary entry in order to check the flow of undocumented migrants; while the latter, enhancing the existing law and including the permission for the Immigration and Naturalization Services (INS) authorization â€Å"to bar reentry to the United Stat es if an alien overstayed his/her visa deadline for departure† (Adams 56). Many were not satisfied with the results of these measures. To borrow Adams’ words: The spirit and framework of both the 1986 and 1996 immigration laws failed to address the grassroots flow of aliens at the source – the official government attitude and immigration policy avoidance by Mexico. In spite of the fact that from 1994 to 2001 (pre-9/11) the annual U.S. border enforcement budget of the INS and the Border Patrol nearly tripled to over $2.5 billion, the immigrant flow continued nearly unchecked (56). A good part of the years after, a growing debate emerged as to how to best address the issue. In 2004, as part of the increasing impact of the September 11, 2001 terrorist attack in New York, immigration policy took an increasing relationship to terrorism and border security. For example, the United States Visitor Immigration Status

Operational Requirements And Service Conditions Of Piston Engineering Essay

Operational Requirements And Service Conditions Of Piston Engineering Essay ABSTRACT There is an extent in changing the trend of the material by its properties and its characteristic. The majority of the materials completely depend on the application of the material in the component and its versatility. The components by material vary from each other by its properties. The materials have the tendency to change its manufacturing process by its character. A component can be manufactured by using various materials depending according to the application and its life. In this paper we discussed about the manufacturing process of the components like piston, connecting rod and the crank shaft. The alternative methodologies and usage of alternative materials are also explained by using CES chart with its advantages. INTRODUCTION Selecting the appropriate material is an integral part of the successful implementation of an engineers design. A design engineers ability to objectively quantify the combined marketing, technical and manufacturing requirements as they apply to the material selection is critical to the actual as well as the perceived success of the product. This paper contains a deep knowledge about the selection of the material and its manufacturing procedure with justification. CHAPTER 1 GENERAL COMPONENT DETAILS 1.1 PISTON The piston is the most essential component of the engine which actually transfer the energy output from the combustion chamber to the crankshaft through connecting rod. This is a pressure-tight cylindrical plunger which is subjected to the expanding gas pressure. Basically, piston structural components are head, skirt, gudgeon pin, grooves and lands. 1.1.1 OPERATIONAL REQUIREMENTS AND SERVICE CONDITIONS OF PISTON Hence in order to transmit this high power output the piston must be designed lightly and must be robust. The piston must be of higher strength material that can with stand the high pressure that is been generated due to the burning of air-fuel mixture within the cylinder. Piston must be fitted properly to control the expansion due to temperature, without which the piston will fit loosely when in cold and they bind themselves when it gets warmed. 1.1.2 FUNCTIONS OF PISTON Transmit energy from combustion unit to piston pin, Serve as a carrier for the piston ring which seals the compression in the cylinder, Act as a guide for upper end of the connecting rod, Withstand high temperature expansion Despite the heat energy to the coolant. piston.gif Fig(1) Piston Assembly Conditions of piston at normally high speed, Piston moves from the top to bottom of the cylinder and vice versa with a acceleration of speed of around 50mph at midpoint and decelerates. The piston is subjected to pressure of about 6.8MPA. The piston is subjected to temperature of about 315 °C.[1] 1.1.3 DESIRABLE MATERIAL CHARACTERISTICS The Piston materials must meet the following conditions, [2] Low thermal expansions for arresting the hot gases. High thermal conductivity for releasing heat from piston head. High strength to mass ratio (light weight) for transmitting high power output. High fatigue strength for increasing the material strength. Good resistance to surface abrasion. To reduce skirt and ring groove wear. 1.2 CONNECTING ROD Connecting rod is a part of the engine which connects the piston to the crankshaft. This connecting rod converts the linear motion of the piston to rotating motion to the crankshaft. 1.2.1 OPERATIONAL REQUIREMENTS AND SERVICE CONDITIONS [] Connecting rods should be made as long as possible to reduce the oblique angle by the cylinder axis. Both tensile and compressive stresses are produced due to piston reciprocating-inertia loads. In order to evade scuffing proper lubrication is needed. Lubrication of the small end by a hole drilled along the shank should be so arranged that the hole intersects the big end bore circumferentially. To prevent buckling the rod shank is made in an H section, i.e., with a central web and two end flanges. Intense heat is generated at high rotational speed, so large bearing area is required to make the rod wear well. They should be checked for the correct length, weight distribution, straightness and freedom from twist. 1.2.2 FUNCTIONS OF CONNECTING ROD As the word is self explanatory, the connecting rod connects the piston and the crankshaft. The connecting rod continuously transmits energy from the combustion chamber to the crank shaft. It actually converts the reciprocating motion of the piston to the rotary motion of the crankshaft. These dynamic motions of the connecting rod makes it as light as possible whilst having a rigid section. 14900_19847.jpg 1.2.3 DESIRABLES MATERIAL CONDITIONS Must be strong to remain rigid under loading and light enough to reduce the inertia forces. Material must have good elastic modulus. It must have high fatigue strength in order to avoid failure due to high cycle fatigue. Heat capacity of the connecting rod must be high. Must withstand buckling stress due to large compressive loads. Must be of low density to avoid bearing failure. 1.3 CRANKSHAFT Crankshaft is the central link-up for the power produced by each cylinder in the engine. This crankshaft is one of the heavier part of the engine which is to be made strong to withstand the load from the con-rod. 1.3.1 OPERATIONAL REQUIREMENTS AND SERVICE CONDITIONS Fillet areas locations are to be verified since both torsional and bending loads are experienced during its service life. Counterbalancing of weight is to be considered in order to counteract the centrifugal forces created by crankpin. The projected areas of the big-end and main-end journals must be adequate to withstand maximum cylinder pressure. After grounding should have a surface finish of 0.5 µm to minimize bearing wear. Crankshaft must have the capacity to absorb the thrust loads from clutches or torque converter. 1.3.2 FUNCTIONS It transmits power from combustion chamber to the flywheel through piston, piston rings and connecting rod. It harness and phase the individual cylinders power impulses transmitted through the mechanism of the connecting rod which converts the reciprocating motion of the piston to rotary motion at crankshaft. It changes the linear displacement due to sudden shock caused by the combustion chamber into smooth rotary motion which is the input to many devices. Crankshaft rotates in the cylinder in the cylinder block of the main bearing which supports the crankshaft which reduces the excessive wear. http://www.motorera.com/dictionary/pics/c/crankshaft.gif 1.3.3 DESIRABLES MATERIAL CHARACTERISTICS Material nominal stress must not exceed 20% of tensile strength in bending and 15% in torsion. Must have the capacity to withstand large force from gas combustion. Must have high heat withstanding capacity. Must have low thermal expansion. Must have high adequate strength, toughness, hardness, and high fatigue strength. CHAPTER 2-MATERIAL SELECTION 2.1 MATERIAL SELECTION FOR PISTON[hh] Material selection process is an integral part of the overall product development process and must be considered in the early phases of the product definition. The material chosen for manufacturing the product is based on the following consideration, Mass consideration Strength and wear consideration Heat-conduction consideration Expansion consideration Based on the above considerations the aluminium alloys satisfies all the factors comparing to cast iron and steel. Mass consideration: Since the pistons reciprocating force is high at high speed, it is necessary to turn to light material instead of cast iron and steel. It has a relative density of 2.6 when compared with 7.8 for cast iron. Strength and wear consideration: Since pure aluminium has low tensile strength of 92 to124 N/mm2 and fall of to 31N/mm2 at 300 °C, it is always alloyed with copper or silicon for piston materials which improves the strength to mass ratio. At high level of silicon, the alloy exhibits excellent surface hardness, wear resistance properties and excellent dimensional stability. Heat-conduction consideration: The better heat dissipation of aluminium-alloy pistons compared to cast-iron pistons greatly reduces the maximum piston-crown operating temperature of 250C 300C for allou pistons and 400 to 500C for cast iron. Expansion Consideration: The thermal expansion is less for Al-Si alloy which has a thermal expansin of 0.000 021 and 0.000 017 per  °C for 12% Si alloy and 22% Si alloy. Fig() CES chart 2.1.1 SURFACE CONSIDERATON: Due to high speed reciprocation of the piston there may be so many losses or issues that must be considered. In that the frictional losses in piston assembly are majorly due to generation of heat. Subsequent raise in temperature can have this effect in the operation. In order to overcome this problem, proper material with good thermal conductivity is chosen. 2.2 MATERIAL SELECTON FOR CON-ROD The connecting rods are crucial and highly stressed component of the automotive engine subjected to alternative tensile and compressive stresses. Hence the material must be chosen based on the following conditions; Good elastic modulus, High fatigue strength, Low density to avoid bearing failure and High heat capacity. Based on the following conditions microalloyed steel is chosen which meets all the requirements mentioned above. This steel has a hardness level of 20-30 HRC. Small microalloying additions of vanadium and niobium are used to increase the strength of carbon steel plates. 1.1%Mn-0.5%Cr is the best combination to obtain thee high fatigue strength. Lowering the carbon content down to 0.33% and increasing the vanadium content to control the hardness gives toughness which improves the fatigue strength of free machining grades with S and Pb. The finally obtained chemical composition is 0.33%C-1.05%Mn-0.5%Cr-0.12%V-.055%S-0.20%Pb-Ca which has fatigue strength of 26% higher than a conventional microalloyed forging steel. As for connecting rod, application of light metal like titanium alloys and aluminium alloys are been tested, due to high cost in light metal the connecting rod are made of microalloyed steel. This structure contains ferrictic-pearlitic-bainit. Fig() CES chart 2.2.1 SURFACE CONSIDERATION The connecting rod is one of the highly stress concentrated part of the automotive engine. It is known that in the four cycle engines the connecting-rod small end is particularly stressed when the con-rod is at top dead centre at the beginning of the induction stroke, since the small end is ovalized by the tensile inertial forces exerted by the mass of the piston assembly. During both the stroke condition (expansion and compression) gudgeon pin pushes the small end along the lower end of the arc, by which the compression load directly acts on the con-rod without considerably stressing the eye. The eye is therefore subjected to repeated stresses, whereas the con-rod shank stress are reversed.(10) 2.3 MATERIAL SELECTION FOR CRANKSHAFT (hh) Crankshaft are from materials which can be readily shaped, machined and heat-treated and which have desirable mechanical properties such as adequate strength, toughness, hardness and high fatigue strength and of course , low cost. The highest quality steels are usually specified for satisfying the constraints given. Metals with optimum combination of bending and the stiffness are identified by creating a charts in CES by using performance indices in axes. From the figure it is clear that the low carbon steel, high carbon steel, low alloy steel and medium carbon steel are satisfying the given constraints. Low alloy steel with chromium-molybdenum is used for crankshaft. This forging steel is suitable for medium to heavy-duty petrol and diesel-engine crankshafts. It presents no difficulty in hot working and afterwards can be easily machined to size. The alloying composition is 0.4% carbon, 1.2% chromium and 0.3% molybdenum. 2.3.1 SURFACE CONSIDERATIONS Since crankshaft is the most highly strained part of the engine with high load acting on it the following factors must be considered. Pitting failure can occur in the crank-pin Due to lack of surface integrity lack of control over stress and temperature. CHAPTER 3 MANUFACTURING PROCESS 3.1 MANUFACTURING PROCESS FOR PISTON[SS] Based on the material selected as aluminium alloys for piston, the manufacturing process is carried-out through casting because of its capability to produce near-net shaped parts at the required production rate. Hence the process selected for this component is the Gravity die casting. 3.1.1 GRAVITY DIE CASTING The pistons are produced from high-silicon alloys, such as 413.0 aluminium alloy. This alloy has high fluidity and can create high-definition surfaces through permanent mould casting; it also has high resistance to corrosion, good weldability, and low specific gravity. The universal acceptance of aluminium pistons for internal combustion engine applications is due to mainly to their light weight and high thermal conductivity.[ss] This type of casting is suitable for high volume production. The main advantages are the dimensional accuracy and surface finish. Castings ranging from few grams to 100kgs of aluminium alloy could be casted. This process could achieve higher mechanical properties than other casting by heat treatment. Since silicon has got good properties like, low shrinkage and imparting high fluidity which results in good casting. The maximum amount of silicon in cast alloy are in range of 22%-24%.(11) Manufacturing route: [ss] The h13 tool-steel mould is preheated to 200 °C to 450 °C, depending on the cast alloy and part size. Initially, the preheat is achieved with a hand-held torch, the mould reaches a steady-state temperature. Molten aluminium is heated to between 100 °C-200 °C above its liquidus temperature as shown below. Once the molten shot is in place the piston drives the mould in its place. Because of high thermal conductivity of the mould material, heat extraction from the molten metal is rapid and the metal solidifies in small channels before filling the mould completely. [9] 3.1.2 MICROSTRUCTURAL CHANGES Silicon has a diamond crystal structure and is consequently very brittle. These silicon structure damage the mechanical properties and nucleates on aluminium phosphide particles that is present in the melt as impurities. Further addition of sodium to the melt getters the phosphorous, which thereby increases the difficulty of sodium nucleation. Solidification is suppressed to lower temperature where the nucleation rate is large. This leads to remarkable refinement of microstructure. [9] Aluminium Silicon [9] From the figure above the dark feature is a shrinkage pore caused by a casting defect. This figure shows the coarse silicon plates in an aluminium matrix. 3.2 MANUFACTURING PROCESS Microalloyed connecting-rod is manufactured by a simplified thermomechanical treatment like controlled cooling following hot forging. Through these processes desired properties could be obtained without quenching and tempering treatments. Hence powder forging was selected which would conveniently satisfy the manufacturing process for the selected material and component. 3.2.1 POWDER FORGING Powder forging rods are manufactured by combining metal powders into a pre-form that is sintered and reheated to forging temperature. Then it is completely forged to its final shape and machined to its final dimensions. This mixed powder is compacted at room temperature and high pressure upto to 200 to 400MPa. At the end of the process the powdered material acquires a density of 70 to 85%. This process has resulted in fully dense shape part which makes it suitable for high performance applications where high durability and strength are required. The detailed manufacturing route of this PF process is shown below: [12] The advantages of using PF process are, Good dimensional accuracy Minimum scattering of weight Energy saving [12] 3.2.2 MICROSTRUCTURE [13] [13pdf] From the photograph of the microstructure of the connecting-rod material it is clear that the component contains pearlite and ferrite materials in composition. The above picture clearly indicates that in the powder metal connecting rods oxides are removed from the material surface by shot peening but the oxides are entrapped and remain below the surface causing the crack to originate below the surface . 3.3 MANUFACTURING PROCESS 3.3.1 FORGING [ss] The material selected for the crankshaft is forged steel which has a desirable mechanical properties such as adequate strength, toughness, hardness, and high fatigue strength. Hence the suitable manufacturing process for this steel is forging. Forging is a basic process in which the work-piece is shaped by compressive forces applied through various dies and tooling. For this forging process the dimensional tolerance range from  ±0.5 to  ±1% of the forging dimensions. At higher temperatures of about 700 °C dynamic forging recrystallisation occurs which increases the stress and strain deformation of the metal to make it hard. Manufacturing route: Prepare a slug or billet Heat the work-piece in the suitable furnace For hot forging, preheat and lubricate the dies Forge the billet in appropriate dies and in the proper sequence Clean the forging and check its dimensions Perform additional operations such as heat treatments and straightening Inspect for defects In the hot forging process to form a metal billet two or more dies are brought together to each other at a suitable room temperature in a shape of the die impression. This process follows two basic requirements, The strength of the material must be low so that the die pressure can be kept within the limits. The material should be capable of deforming without failure and should allow required amount of deformation. The flow of metal and die filling are mainly determined by (i) flow stress and cooling ability (ii) friction and cooling effects at the material interface. In this process, definite amount of heat is received by all the parts after machining in heat treatment process. This is mainly carried-out to improve fatigue and wear properties. High quality parts with moderate cost can be made by this process. Thus this process offers high strength to weight ratio, toughness and resistance to impact and fatigue to the material which is considered in the performance of the crank shaft. [14] 3.3.2 MICROSTRUCTURE Heating above recrystallisation temperature causes recrystallisation that removes the microstructure deformed and generated recrystallised grains. After eutectoid-carburizing martensite transformation takes place and a black portion near the surface is formed consisting of fine grains of ferrite and carbide. On quenching from the austentite (ÃŽ ³) phase martensite is formed. This transformation is a diffusion-less shear transformation . Martensite is too brittle in plain carbon steel for practical applications and is subsequently tempered to restore some toughness. CHAPTER 4 ALTERNATE MATERIAL 4.1 ALTERNATE MATERIAL FOR PISTON[hh] Cast iron refers to the family of ferrous alloys composed of iron, carbon ranging from 2.11% to about 4.5% and silicon of about 3.5%. They are classified by their structure ferritic, pearlitic, quenched and tempered or austempered. The equilibrium phase diagram relevant to cast iron is shown below where right boundary is 100%C. The eutectic temperature is 1154 °C and thus cast irons are completely liquid at temperatures lower than those required for liquid steels. One of the major disadvantage of the aluminium as the base metal of the piston is that it has high co-efficient of linear expansion in the range of 0.0000221per °C, compared with 0.0000117per °C of cast iron. Aluminium has twice the expansion rate of cast iron. Cementite is metastable (not completely stable) which has a tremendously low decomposition rate. However it can be made decomposed into alpha-ferrite and graphite. The graphitization can be controlled, promoted and accelerated by adding silicon, controlling the rate of cooling and modifying the composition.[ss] [15] 1.4.1 LIMITATIONS Relative density is high of about 7.8 When in tension, the presence of graphite acts as a stress riser weakens the material. Strength properties of the cast iron are significantly affected by the shape and size of graphite. Higher material and manufacturing cost. The major disadvantage is the shrinkage. 1.4.2 POTENTIAL BENEFITS Presence of graphite in cast iron improves wear-resistance as it acts as a lubricant. High carbon content-degradation of ductility and fracture toughness. Good corrosion-resistance. Easy machinability Wide range of composition and microstructures-easy weldability. 4.2 ALTERNATE MATERIAL FOR CON-ROD The alternate material chosen for connecting rod is aluminium alloyed material as it is light in weight and provides long service life to the part. The aluminium alloys are high strength-to-weight ratio, resistance to corrosion by many chemicals, high conductivity and ease of formability. The material composition of aluminium is 7.6 to 8.4% Zn,1.8-2.3%Mg, 2-2.6%Cu, 0.08-0.25%Zr, 0.10%Si, 0.15%Fe, 0.05%Mn, 0.04%Cr and 0.06%Ti. When compared to othe alloys it convinces the constrains like low thermal expansion, wear-resistant, high fatigue strength and buckling. Majorly this material is chosen based on the following consideration: Mass consideration Strength and wear consideration Expansion consideration Heat-conduction consideration http://www.streetperformance.com/ART/PRODUCTS/100687/14012-8.jpg[19] 2.4.1 LIMITATIONS It is more expensive than cast iron. Low dimensional accuracy and poor surface finish. Solidification is very slow. Occurrence of fracture in short transverse direction. Expansion rate is high when compared to cast iron with oure aluminium. 2.4.2 POTENTIAL BENEFITS Aluminium alloys can be easily machined and welded and formed. High dimensional accuracy with long service life. High yield strength in both tensile and compression. Aluminium is much better conductor of heat than cast iron. Aluminium alloys provide improved resistance to abrasion and produce strength over temperature range. Improves the performances of the piston and thus the engine. 4.3 ALTERNATE MATERIAL FOR CRANKSHAFT As the crankshaft is the heavier moving part in the automotive engine, the material selected for this part has to be strong and light. Titanium alloys having high strength with reduced weight is used for crankshaft until and unless cost is not considered, as this material is very expensive. http://amt-advanced-materials-technology.com/s/cc_images/cache_867254901.jpg[17] 4.3.1 POTENTIAL BENEFITS OF TITANIUM ALLOYS Titanium has high melting point of about1678 °C which specifies strong creep and strength above wide temperature range. The density is about 55% of steel with comparable strength. Ti alloys exists in two allotropic forms ÃŽ ± and ÃŽ ² Presence of thin oxide surface film-resistance over atmospher and sea environments including chlorine and organic chemicals. Reacts rapidly with oxygen, nitrogen and constituents in cutting tools at high temperature. 4.3.2 LIMITATIONS Embrittlement occurs during fabrication because of susceptibility of hydrogen, oxygen and nitrogen. Forging with titanium alloys is expensive but it increases the strength of the material. Ti alloys has a tendency to madden when tightening with connecting rod using bolt. Titanium is more difficult to machine due its reactive nature. Niobium Titanium[16] CHAPTER 5 ALTERNATE MANUFACTURING PROCESS 5.1 ALTERNATE MANUFACTURING PROCESS FOR PISTON 5.1.1 SAND CASTING Sand casting is a one of the most feasible manufacturing process where the unit production is comparatively less. In this process a mixture of sand and clay is compacted around the pattern in which the pattern retains the shape of the original component to be produced. Then the pattern is removed in order have the cavity in the shape of the pattern. Generally low cost wooden patterns with gateways and runner are used. The molten metal is poured into the gateway by which it runs through the runner and fills the cavity and forms the exact shape of the cavity. Actually this whole system is housed in a box called flask. After which the molten metal allowed to solidify by cooling it. As the molten metal is solidified the sand pattern is broken and final work is done to obtain the finished component. The figure below shows the manufacturing process of the sand casting in detail. http://openlearn.open.ac.uk/file.php/1689/T173_2_020i.jpg Fig(8.1) Sand Casting Process [18] 5.1.2ADVANTAGES Low tooling and equipment cost Component with any complicated shape can be produced Relatively cheap process Possibly components can be produced in large quantity. 5.1.3 DISADVANTAGES High tolerance ratio is required Labour cost is high. 5.2 ALTERNATE MANUFACTURING PROCESS FOR CON-ROD 5.2.1 SQUEEZE DIE CASTING Squeeze die casting or liquid metal casting involves the process of solidification of molten metal under high pressure. The machinery includes a die, punch and ejector-pin. Under the pressure applied by the punch keeps the entrapped gases in solution and the rapid heat transfer takes place at the die-metal contact which results in fine microstructure with good mechanical properties.[ss] Elimination of shrinkage and gas porosity happens because of precise metal metering, quiescent die filling and high pressure. 5.2.2 ADVANTAGES Precise dimension, Excellent surface finish, Fully shaped component is obtained Complex part can be made to near-shape. 5.2.3 DISADVANTAGES High initial cost Limitation of high fluidity metals[20] 5.3 ALTERNATE MANUFACTURING PROCESS FOR CRANKSHAFT 5.3.1 FORGING In forging operations the metal is squeezed to shape by die in which the metal is subjected to large plastic deformation. These metals are placed in-between closed dies under high temperature and pressure which results in succession of the final shape. http://www.forcast.ca/images/00436_faq1.gif[21] Forgings generally are subjected to additional finishing operations, such as heat treating to modify properties and machining to obtain accurate final dimensions and surface finish. 5.3.2 ADVANTAGES Good utilizations of materials Good dimensional accuracy High production rate Good reproducibility Low die costs 5.3.3 DISADVANTAGES Initial cost is high Not economical for small quantities Machining often necessaries

Graduation Speech: The Quest for Wisdom :: Graduation Speech, Commencement Address

There is a distinct difference between knowledge and wisdom. I can tell you that as honor society president I have seen many smart people do stupid things. Let's just say that mixing a very large lunch with a bobbing ship and an admissions officer from the University of California equals a vomitous situation. Today, we are sitting here celebrating the fact that we spent four long years in high school matriculating, which means actually learning to use words like matriculation. But I am going to go out on a limb and say that while we have acquired all of this knowledge, we are still incredibly dumb, and I am not referring to WASL scores, I mean that we have not had the opportunity to apply our knowledge. Just as I was completely unaware of my propensity for sea sickness, many of us have not had the opportunity to grow wiser. The class of 2006 has advanced technology at its fingertips. However, we must remember that the Internet, television, and cell phones really are artificial intelligence, all they do is retain information. It is our job to apply it. Within the past year we have had many unfortunate reminders of the difference between knowledge and wisdom, now we are learning that certain bureaus within the federal government were aware of the possibility of a terrorist attacks, but clearly the appropriate proactive measures were not taken. You see knowledge: merely being aware of information is absolutely useless. Wisdom: knowing what to do with information is invaluable- in this case it meant the difference between discourse and recourse, and the loss of thousands of lives. So while we are accustomed to our artificial intelligence, it is time we become wise. More than ever it is important that we are wise about our rights. After Sept. 11 there was an immediate scramble to tighten security. Random searches of our persons, our vehicles and our homes suddenly become acceptable because of fear. The most common response to these encroachments is as one passive Washington state ferry rider put it: "why should i care? I have nothing to hide." We should care because unwarranted searches are a regression of everything we have built this nation to be. We know what our rights are, but what are we doing to protect them? In an effort to protect the U.S. our first step is to unravel many of the things we stand for.

Private Schools vs. Public Schools Essay

Private Schools VS. Public Schools Parents often wonder how to start off their children’s education. Depending on ones religion or beliefs a private or public school is a choose most parents face. Of course, each school offers it’s own pros and con’s the choice is simple. Public schools offer the best well rounding of a student. While being enrolled in a public school, students are faced with real outside world problems, are with a different blend of students each year, and are also introduced to the latest technology faster. While, a public school the money is offered to them by the state easier then having donations like a private school. Ones child will most likely be with the same students throughout their educational years. Classes aren’t as big and varied like classes at public schools. While in a public school, children view the wide spread cultures and human beings that make up today’s American society. Public schools have a wider variety of classes, which give students an opportunity to choose the classes the want. These classes allow students to pursue a career from the knowledge they have obtained. For example, one might take a business class, which could lead to a career in the business industry. On the other hand, in Private schools they only provide the necessary classes required by the state. In some intermediate private schools, Home Economics and Shop classes Brady 2 aren’t even offered. Unlike Public schools these classes have been offered since fifth or sixth grade and up. The uniforms in private schools ones child will be wearing would not allow the child to show character in his self. Uniforms may make life easier in the long run, but think of how many different ways in style people express themselves. There’s skater, prep, sporty, gothic, hippie, or whatever is convertible. In public schools, ones child has many different ways to fit in or dress how they feel is convertible to them. The sports in private schools aren’t that excelled as ones in public schools. Like in private intermediate schools there are not a variety of sports. Public schools offer sports as young as their primary schools. Sports in Public schools seem to be widely known and are more funded. The money that Public schools receive go towards uniforms, equipment, and top of the line coach’s. Public schools show to the community that they will educate and well round you child better then Private schools. Private schools will limit your children’s ability to grow. Although your child will receive religion in school as another subject, is it really worth it to you to have your child be deprived of the opportunity that will lead them to be a better person?

Zero Tolerance Policy Go to Far essays

Zero Tolerance Policy Go to Far essays DOES THE ZERO TOLERANCE POLICY GO TO FAR? Does the Zero Tolerance Policy go to far? According to Websters Dictionary, the definition of zero is naught: none; the defintion of tolerance is patience. The meaning of Zero Tolerance infact means both. Zero Tolerance in the school system means that teachers, administrators and school officials are to have no leniency towards any wrong behavior and must take drastic action to stop it immediately. A public shaken with images of children killing children in school hallways may be applauding a new emphasis on stricter punishment of students who even hint at violent behavior, but when zero tolerance becomes zero options, it has gone way to far. The tendency to go to far is a predictable reaction from school officials tring to cope with a chain of recent school shootings. I believe that the schools now take everything a child does since the shootings, way to seriously. THese zero tolerance policies tend to be so inflexible that it tends to be an overreaction. THere is no room for discretion for one child and not the next, one punishment for all even if that is the differance between an innocent child playing a game and a violent child with a real problem and an intent to cause harm to others. A 6 yr old boy in Colorado Springs, COlorado learned the hard way about zero tolerance. The year was 1997 and police and ambulance were called to the elementary school because the first grader gave a lemon drop to another student and a teacher thought it was a drug since she didn't recognize it. The boy was suspended for half a day because it was considered a drug since it was only sold in health food stores. The action taken was drastic for kids sharing candy, isn't it what our mom's tell us to do and the poor kids was suspended for it. Three children were caught playing withwater guns and the result was that these three boys faced expulsion hear...

Privatization Essays - Market Structure, Monopoly, Privatization

Privatization Essays - Market Structure, Monopoly, Privatization Privatization Privatization What is Privatization? Privatization is the process of transferring productive operations and assets from the public sector to the private sector. Broadly defined in this fashion, privatization is much more than selling an enterprise to the highest bidder, as it includes contracting out, leasing, private sector financing of infrastructure projects, liquidation, mass privatization, etc. My testimony will argue that there is no single best approach to privatization; the appropriate privatization path depends on the goals that the government is seeking to attain, the individual circumstances facing the enterprise and the economic and political context of the country. It should be noted that privatization is fundamentally a political process as well as a commercial and economic process. Privatization changes the distribution of power within a society, as it diminishes control of the economy by the state and government- appointed managers. Workers often feel threatened by the potential changes inherent in privatization, although employees frequently benefit from the process. As a result, public support is a major consideration in any privatization program and many of the choices made in designing and implementing transactions reflect the need for such support. Two consequences flow from this factor. 1) choices of approaches are sometimes altered due to political considerations, meaning that equity must be promoted in the privatization strategy, and 2) program implementation must be objective and fair to avoid adverse publicity. What are the goals of privatization? Many goals are often pursued through privatization programs. These goals often fall along two principal dimensions: 1) broad social or macro economic goals, and 2) enterprise specific or macro economic goals. Macro economic goals are numerous. Fundamentally, privatization is advocated as a means to reduce the governments role in the economy, partly as a philosophical matter (as in the UK) but principally because governments have performed badly in that role. Many countries can attribute substantial portions of their external debt to liabilities of state-owned enterprises and significant portions of government budgets are devoted to paying subsidies or otherwise assisting loss-making State-owned enterprises. Government's objectives in these situations are often simply to extricate themselves from these financial commitments, and focus scarce

Analysis Essay Example | Topics and Well Written Essays - 250 words - 20

Analysis - Essay Example Other necessary laws of the establishment of socialist community include the union of the class that is working with the peasantry, other echelons of laboring masses; the abolition of capitalist’s assets and creation of civic ownership of ways of manufacturing (Huberman, 174). Gradual socialist transition of the sector of agriculture, planned economy development, aims at creating socialism and improving employee’s living standard. There are other basic laws of the creation of a socialist community. They involve socialist’s revolution in culture, ideology and the making of a significant intelligentsia ardent to the working class, to all people who are toiling, and to the ways of socialism. Principle laws in the creation of socialism include the eradication of state oppression and the formation of fraternal friendship and equality among states (Huberman, 196). Socialist defense rises from attacks by domestic and foreign enemies. International proletarian is equally essential involving cohesion of working class in each nation with those of other countries. Several Marxist authors share the views of Leo. Sweezy Paul shares the same ideas as Huberman. Through review by Kirkus, there is need for understanding and study of social history and economic of assets from the angle of modernity. All people find it interesting is studying such transition from the feudal days to the current communism. Huberman, Kirkus, and other Marxist authors infiltrate basic reasons for backing changes in economy. Effort and sympathy are in the direction of people and labor. They are against capitalism, even though they recognize and admit the input, which the system of capitalism has made (Huberman, 217). The texts bring the general image of the prospect of the world of economy and the nation’s wealth. Socialist economic organizations have been established due to communist socialization of the ways of production. The major

American Constitution Law 1.1 Essay Example | Topics and Well Written Essays - 750 words

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