Introduction Of Engine Block

Introduction Of Engine Block Until recently, cast iron and aluminum alloys have been successfully used to manufacture most diesel and conventional gasoline-powered engine blocks. However, with a greater emphasis on increasing the efficiency of the engine via weight reduction, there is a search for alternative alloys that are lighter than cast iron and aluminum alloys, while retaining the necessary strength to withstand the forces of an engine. In the late 1990s engine blocks made from plastic and other experimental materials were being used in prototype cars with the hope of developing more lightweight, efficient vehicles . Also lately new manufacturing processes have been developed that have brought to light two new alloys suitable for use in an engine block, magnesium alloy AMC-SC1 and compacted graphite cast iron (CGI). Thus this project will cover, the functional requirements of the engine block, the processes used to manufacture the part, and the mechanical properties of the alloys. INTRODUCTION: Todays engines are an integral component of an automobile that are built in a number of configurations and are considerably more complex than early automotive engines. The use of lighter and stronger engineering materials to manufacture various components of the engine has also had an impact allowing engineers to increase the power-to-weight of the engine, and thus the automobile. Since the engine block is also a relatively large component, it constitutes 20-25% of the total weight of an engine. Thus there is much interest in reducing the blocks weight.[Keay, Sue: Diet of Australian metal lightens cars and pollution, Media release, 14 October 2002.] Many early engine blocks were manufactured from cast iron alloys primarily due to its high strength and low cost. But, as engine designs became more complicated, the weight of the engine (and thus the vehicle) had increased. Thus the need to come up with lighter alloys that were as strong as cast irons arose. One such material that was being used as a substitute was aluminum alloys. Together, these two metals were used exclusively to fabricate engine blocks. Lately , however, a new material process has made a magnesium alloy suitable for use in engines. The alloy, called AMC-SC1, weighs less than both cast iron and aluminum alloys and represents new possibilities in engine manufacturing. A new manufacturing process have made compacted graphite cast iron (CGI) a viable alternative to gray cast iron for the manufacture of diesel engine blocks. Like magnesium alloys, this material offers a higher strength and lower weight than gray cast iron. Thus this section will cover materials used to manufacture engine blocks , component discussion, its functional requirements, and the materials used to manufacture the part. The mechanical properties of the individual alloys will be incorporated, along with the manufacturing processes used to fabricate the component. DESCRIPTION OF THE PRODUCT: WHAT IS AN ENGINE BLOCK? : The engine block is vital structure of vehicles which run on internal combustion, providing the powerhouse for the vehicle. The engine block is termed a block because it is usually a solid cast, housing the cylinders and their components inside a cooled and lubricated crankcase .Common components found in an engine include pistons, camshafts, timing chains,rocker arms, and other various parts. When fully stripped of all components, the core of the engine can be seen: the cylinder block. The cylinder block (popularly known as the engine block) is the strongest component of an engine that provides much of the housing for the hundreds of parts found in a modern engine. The block is typically arranged in a V, inline, or horizontally-opposed (also referred to as flat) configuration and the number of cylinders range from either 3 to as much as 16. Figure 1 shows engine blocks with V configuation. opposed configurations. Functional Requirements of a Cylinder Block: Because engine blocks are a critical component of an engine, it must satisfy a number of functional requirements. These requirements include withstanding high cycle fatigue stresses, thermal strains, and aggressive wear conditions over the full life of the engine, housing internal moving parts and fluids, ease of service and maintenance. REQUIRED MATERIAL PROPERTIES: The one-dimensional era of engine design is finished. The current approach considers the loads acting at each point of the engine block. (Vollrath, 2003) In order for an engine block to meet the above functional requirements, the engineering material(s) used to manufacture the the cylinder block material should have adequate strength and rigidity in compression, bending, and torsion. This is necessary to resist the gas pressure loads and also for the components, which convert the reciprocating motion of individual piston into a single rotary motion. The cylinder-block material should (a) be relatively cheap, (b) readily produce castings with good impressions, (c) be easily machined, (d) be rigid and strong enough in both bending and torsion, (e) have good abrasion resistance, (f) have good corrosion resistance, (h) have a high thermal conductivity,(to prevent failure under high temperatures). (i) retain its strength at high operating temperatures, and (J) have a relatively high thermal expansion, low density.(to resist expanding under high operating temperatures) High strength is a particular concern in diesel engines, since compression ratios are normally 17.0:1 or higher compared to about 10.0:1 for conventional engines. , and thermal conductivity . Good machinability and castability of the metal alloy are also important factors in selecting the proper material, as the harder it is to machine the product, the higher the costs of manufacturing. In addition to the previously mentioned properties, the alloys must possess good vibration damping to absorb the vibrations of the moving parts. METALS USED IN THE MANUFACTURE OF THE CYLINDER BLOCKS: Based on the functional requirements of the cylinder block and the material properties required to meet the functional requirements, industries have used cast iron and aluminum alloys to manufacture the blocks. EXISTING MATERIALS: 1)Cast iron alloys are used because of the combination of good mechanical properties, low cost, and availability. 2)Certain aluminum alloys combine the characteristics of iron alloys with low weight, thereby making the material more attractive to manufacturers who are seeking a competitive edge. NEW MATERIALS: 3)Compacted graphite cast iron is lighter and stronger than gray cast iron, making the alloy a more attractive alternative to the latter in the production of cylinder blocks, particularly in diesel engines. 4)Magnesium alloys, which were previously unsuited for use as an engine block material, have the advantage of being the lightest of all the mentioned metals, yet still retains the required strength demanded by a block. 1)GRAY CAST IRON ALLOYS: Gray cast iron alloy have been the dominant metal that was used to manufacture conventional gas-powered engine blocks. Though extensive use of aluminum alloys has minimized the popularity of this material, it still finds wide use in diesel-fueled blocks, where the internal stresses are much higher. The use of cast iron blocks has been wide spread due to its low cost and good formability. Generally types of gray cast iron of pearlite microstructure is used in the manufacturing of engine block. Gray cast iron alloys typically composition: A typical cast iron is a gray cast iron, which contains 2.5-4 wt.% carbon, 1-3 wt.% silicon, 0.2-1.0 wt.% manganese, 0.02-0.25 wt.% sulfur, and 0.02-1.0 wt.% phosphorus [Anyalebechi, P.N.: Essentials of Materials Science Engineering, January 2005, p. 94.]. and the balance (93.6%) iron. The carbon improves lubrication property of graphite, the silicon controls the formation of a laminated structure, called pearlite, which has good wear resistance, and the manganese strengthens and toughens the iron structure. A common aluminium alloy composition is 11.5% silicon, 0.5% manganese, and 0.4% magnesium, with the balance (87.6%) aluminium. The high silicon content in this alloy reduces expansion but improves cast-ability, strength, and abrasion resistance, while the other two elements strengthen the aluminium structure. While this alloy provides a good corrosion resistance, it can absorb only moderate shock loads. Types of cast iron used in engine block: SAE grade G2500- used for small engine blocks. SAE grade G3500-used for heavy and larger diesel engine blocks. Also some ductile iron are also used in manufacturing engine blocks. SAE AMS 5313C: mechanical properties: [alloying: understanding the basics , by joseph R devis.] Grade or class Hardness HB(a) Tensile strength min(b) MPa Yield strength min(b) MPa Elongtion in 50 mm(2in),%(b) Class A 190 max 414 310 15 Gray cast iron has excellent damping capacity, good wear and temperature resistance, is easily machinable, and is inexpensive to produce. However, gray cast irons are relatively weak and are prone to fracture and deformation. Although cast iron meets most of these requirements, it has a low thermal conductivity and is comparatively heavier. Due to these limitations, light aluminium alloys have been used as alternative cylinder-block materials for petrol engines. Cylinder liners are optional with cast-iron blocks; but are more essential with the relatively soft light aluminum alloy blocks, as they cannot directly withstand wear resistance. Because of the lower strength of the aluminum alloys, the blocks are cast with thicker sections and additional support ribs, so that their weight becomes about half of the equivalent cast-iron blocks. Due to these problems, compacted graphite iron has recently begun to compete with gray cast iron as the choice material to produce diesel engine blocks. COMPACTED GRAPHITE CAST IRON: Compacted graphite cast iron (CGI), which was accidentally discovered while trying to produce ductile cast iron, possesses higher tensile strength and elastic modulus than gray cast iron due to the compacted graphite found on the microstructure of CGI. Figure 8 CGI typical microstructure: 5% nodularity, 9% graphite, 265 particles/mm2. 3. CGI a new combination of properties: As shown in Fig. 8, the compacted graphite iron graphite particles appear as individual worm-shaped or vermicular particles. The particles are elongated and randomly oriented as in gray iron; however they are shorter and thicker, and have rounded edges. The compacted graphite morphology inhibits crack initiation and growth and is the source of the improved mechanical properties, as compared to gray iron. Compacted graphite iron invariably includes some nodular (spheroidal) graphite particles. As the nodularity increases, the strength and stiffness also increase, but only at the expense of castability and thermal conductivity (Guesser et all, 2001). It is usual to set a limit of 20% nodularity for CGI specifications. Table 1 shows mechanical properties of CGI, with grades from 300 to 500 MPa. In the case of cylinder blocks and heads, where castability, machinability and heat transfer are all of paramount importance, it is necessary to impose a more narrow specification. A typical specification for a CGI cylinder block or head can be summarised as follows: 1) 0-20% nodularity, for optimal castability, machinability and heat transfer 2) No free flake graphite, flake type graphite (as in grey iron) causes local weakness 3) >90% pearlite, to provide high strength and consistent properties 4) This general specification will result in a minimum-measured tensile strength of 450 MPa in a 25 mm diameter test bar, and will satisfy the ISO 16112 Compacted Graphite Iron standard for Grade GJV 450. The typical mechanical properties for this CGI Grade, in comparison to conventional grey cast iron and aluminium are summarised in Table 1: Mechanical and Physical Propertiesof CGI in comparison to conventional grey cast iron and aluminium at 20 °C Property Units GJV 450 GJL 250 GJL 300 A 390.0 Ultimate Tensile Strength MPa 450 250 300 275 Elastic Modulus GPa 145 105 115 80 Elongation % 1 to 2 0 0 1 Rotating-Bending Fatigue 20 °C) MPa 210 110 125 100 Rotating-Bending Fatigue (225 °C) MPa 205 100 120 35 Thermal Conductivity W/m-K 36 46 39 130 Thermal Expansion ÃŽÂ ¼m-m-K 12 12 12 18 Density g/cc 7.1 7.1 7.1 2.7 Brinnell Hardness BHN 10-3000 215-255 190-225 215-225 110-150 The results allow the comparison between CGI and gray iron. It can be seen the increase on tensile strength, moving from gray iron to CGI. CGI also shows a higher elastic modulus, when compared to gray iron. [- Mechanical properties of gray iron and CGI grades 400-450. 195-230 HB. Samples taken from the castings (Guesser, 2003)]. Figure 10 [Elastic modulus of gray iron and CGI grade 400. 12.0L I6 cylinder block (Guesser, 2003).] The results in Figure 10 were obtained from two sources: test bars and main bearings of a 12.0L cylinder block. The increase in elastic modulus, from 100 GPa for gray iron to 150 GPa for CGI, results in slighter cylinder bore distortion as reported by Tholl et all (1996), therefore reducing oil consumption and emissions. Results of fatigue strength tests can be seen on figure 11, comparing gray iron grade 250 and CGI grade 450, samples from an I6 5.9L diesel cylinder block. The fatigue limit for the gray iron is 62-79 MPa, depending on the carbon content, while for the CGI the fatigue limit is 175 MPa. The raise of fatigue strength allows the designer to reduce the cylinder block weight. As a result of mechanical properties improvements, a design study conducted by AVL Austria (Sorger Holland, 1999) has evaluated downsizing opportunities for a 1.8 L diesel engine cylinder block, converting from gray iron to CGI. The benefits of this conversion included: 1)9% reduction in overall weight of the finished engine 2) 22% reduction in weight of machined cylinder block 3) 15% reduction in overall length of the finished engine 4) 5% reduction in both; height and width of the finished engine Like gray cast iron, compacted graphite cast iron has good damping capacity and thermal conductivity, but its difficulty to machine has limited the wide-scale use of CGI. A new manufacturing process, however, has opened the way for larger applications of CGI. The development of rotary insert tools has increased the life of the tools used to machine the metal, thus allowing manufacturers to use CGI without worrying about purchasing new tools [Georgiou, George: Iron engines may be in your future, Tooling Production, September 2003, Vol. 69, issue 9, p. 26.]. MAGNESIUM ALLOYS: Magnesium alloys have been used in engines before, but not for cylinder blocks. Rather. The main advantage of this alloy is that the material is much lighter than cast iron and aluminum alloys and has the same strength as cast iron and aluminum alloys[Lampman, Steven: Tuning Up the Metals in Auto Engines, Advanced Materials Processes, May 1991, p. 17.][Anonymous, Magnesium alloy resists high temperature in engine blocks, Advanced Materials and Processes, August 2003, vol. 161, issue 8, p. 13.]. Material scientists and engineers were determined to exploit these characteristics of magnesium alloy and use it to fabricate engine blocks. There were a number of magnesium alloys available that met or exceeded the requirements demanded by manufacturers for an engine block, but insufficient material stability at high temperatures hindered their actual use. Following are the two alloys which have been found suitable for mass production of engine blocks. AMC-SC1: In 2003 material scientists and engineers from the Cooperative Research Center for Cast Metals Manufacturing and the Australian Magnesium Corporation presented their discovery of sand-cast AMC-SC1 magnesium alloy [Anonymous, Magnesium alloy resists high temperature in engine blocks, Advanced Materials and Processes, August 2003, vol. 161, issue 8, p. 13.]. This grade of magnesium alloy contains two rare earth elements, lanthanum and cerium, and was heat-treated with T6. This stabilizes the strength of the alloy at high engine operating temperatures, which is a necessary requirement for a cylinder block material [16]. Bettles et al. had performed experiments to determine the yield and creep strengths of AMC-SC1 and their results are shown in Table 3 [Bettles, C. et al., AMC-SC1: A New Magnesium Alloy Suitable for Powertrain Applications, Society of Automotive Engineers, 2003, p. 2.]. From Table 3, the most significant point is that the yield strength of AMC-SC1 essentially stays the same at 177 °C as it does at room temperature. Table 3: Yield and creep strengths of magnesium AMC-SC1 at room temperature, 150 °C, and 177 °C [17]. Room temperature 24 °C 150 °C 177 °C Yield strength, MPa 120 116 117 Creep strength, MPa 120 98 This means that the material is able to tolerate a wide range of operating temperatures without a loss in strength. Other properties of the magnesium alloy 10 include good thermal conductivity, excellent machining and casting qualities, and excellent damping characteristics. To demonstrate the significant weight savings of magnesium alloy over cast iron and aluminum alloy, consider BMWs inline-6 R6 (shown in Figure 4), which replaced the companys M54 aluminum engine. Its cylinder block is made of AMC-SC1 and is said to have decreased the weight of a comparably-built gray cast iron and aluminum alloy block by 57% and 24% [Jost, Kevin: BMW builds better inline six, Automotive Engineering International, January 2005, pp. 20-32.]. So far, BMW is the only company to have used magnesium alloy cylinder blocks in production vehicles. But, with a significant weight advantage over the current alloys used today and negligible increase in cost, other manufacturers will begin to consider the use of AMC-SC1 and possibly other grades of magnesium alloys for engine blocks. Figure 4: BMWs 6-cylinder R6 powerplant uses a magnesium alloy AMC-SC1-fabricated cylinder block [Jost, Kevin: BMW builds better inline six, Automotive Engineering International, January 2005, pp. 20-32.]. PRODUCTION PROCESS: STANDARD CASTING WITH SOME MODIFICATIONS: This alloy can be cast using a standard production process, with some modifications. For a magnesium alloy engine to be economically viable, it is not merely the cost of the alloy that is important. The casting process must also be commercially viable. There are several modifications required if an existing casting line of cast iron or aluminum is to be converted to one producing magnesium parts. These can be summarised as follows: à ¢Ã¢â€š ¬Ã‚ ¢ A new inhibitor in the sand cores to prevent reaction between the melt and the sand. à ¢Ã¢â€š ¬Ã‚ ¢ A redesign of the runner and gating system to ensure adequate filling (magnesium alloys have a low heat content). à ¢Ã¢â€š ¬Ã‚ ¢ Preheating of the core package to 150 °C. à ¢Ã¢â€š ¬Ã‚ ¢ Modifications to the core package design to allow low pressure rather than gravity filling and feeding. AM-HP2: AM-HP2 A High Pressure Diecasting Magnesium Alloy: The AM-HP2 magnesium alloy has similar high-temperature strength to AM-SC1 and has been specially tailored for use in the high pressure diecasting process. Like AM-SC1, the light-weight alloy significantly increases fuel-efficiency, environmental sustainability and vehicle agility and is suitable for the powertrain components of vehicles, such as engines blocks etc. Need for New alloy:AM-HP2 AM-HP2 has been specifically developed as a diecasting alloy for high temperature automotive powertrain applications, such as engine blocks, structural sumps and automatic transmission housings. The alloy is based upon the successful sand casting alloy, AM-SC1, with a modified composition to make it suitable for the high pressure die casting process. Commercial Opportunities AM-HP2 Magnesium Alloy in the Auto industry: High pressure diecasting is a highly productive process for mass production of light alloy components. While the casting integrity of sand casting and low pressure/gravity permanent mould castings is higher than high pressure diecasting, the latter technology is cheaper. Thus, this process is gaining popularity among auto manufacturers for casting of aluminium engine blocks. It is also the common process for powertrain components such as transmission housings. There is a strong demand in the automotive industry for a suitable high pressure diecasting magnesium alloy for high volume powertrain applications. AM-HP2 exhibits good diecastability and the required high temperature mechanical properties for engine components (including engine blocks) and automatic transmission housings. It has similar creep properties to alloy, AM-SC1. Advantages of AM-HP2 Magnesium over Other Alloys: A key advantage of AM-HP2 is that the alloy is more diecastable than competitor high temperature creep resistant magnesium alloys.Thus, the alloy can be more readily cast into complex shapes with fewer rejects and a wider operating window. The alloy also has better high temperature creep strength than its competitors and thus offers considerable advantage to engine designers seeking to obtain maximum performance for lowest weight and cost. current status of AM-HP2 magnesium development: Pilot scale diecasting trials and laboratory testing of mechanical properties have demonstrated the suitability of AM-HP2 for mass produced powertrain components. PRODUCTION PROCESSES: 3.2 Casting Processes There are two methods used to cast engine blocks for all materials: green sand molding or lost foam casting. The latter, pioneered by General Motors for their Saturn vehicles, have[11] become more popular due to its capability to produce near net shape components, provide tight tolerances for critical components, and reduce machine maintenance and cost [19]. Green sand molding, however, is still widely used in industry as material costs are low and most metals can be cast by this method [Luther, Norris: Metalcasting and Molding Processes, [Online], 22 March 2005-last visited, Available: http://www.castingsoruce.com/tech_art_metalcasting.asp.]. 3.2.1 Green Sand Molding: Green sand molding the common method to cast engine blocks. The term green denotes the presence of moisture in the molding sand . Figure demonstrates the pattern used in sand casting. The pattern mounted into the moulding box along with the runner and ingate system ready to produce a mould. [http://www.dmdaustralia.com.au/block1.html] From Figure 2, a combination of silica sand, clay, and water poured in one-half of the block pattern with a wood or metal frame. The mold is then compacted by squeezing or jolting, and the process is repeated for the other half of the mold. A core consisting of hardened sand is used for support. Then, molten cast iron, aluminum, or magnesium alloy is poured into the combined molds and solidifies. Once the latter part has been completed, the molds are removed, and the cylinder block is cleaned and inspected. Heat treatment of the block is then undertaken to improve the mechanical properties of the alloy for suitable use. [7]. 12 LOST FOAM CASTING: THE PROCESS: Figure 6: Graphical description of the last 6 of 7 methods of the lost foam casting method [Anonymous, Aluminum Cylinder Block for General Motors Truck/SUV engines, A Design Study in Aluminum Casings, pp. 1-31.] The lost foam casting process uses a expanded polystyrene replica of the part being cast. 1)The coated replica/pattern is placed in a flask and loose sand is placed around the pattern and shaken into its voids. 2)Molten metal is then poured through a foam sprue, or funnel, into the sand where the hot metal melts and displaces the foam of the pattern. 3)the metal cools in the shape of the part. The basic steps of the lost foam casting process are: 1) Pattern Molding Bead Pre expansion and Conditioning, Tool Preheat, Pattern Molding, Pattern Aging 2)Pattern/Cluster Assembly 3)Pattern Coating and Drying 4)Sand Fill and Compaction Metal Casting and Cooling 5)Shakeout, Clean-up, and Finishing Lost foam casting is a more reliable and efficient casting technique of the manufacture of engine blocks than green sand molding. The technique begins with the use of polystyrene beads placed in preexpanders for wet expansion to control bead size and density to produce four separate block moldings to be glued together to form the final mold [7, 19]. Next, the metal tool is preheated to remove any moisture and then filled with the beads. The tool is then heated via steam and placed in an autoclave, where it is subjected to high pressures in order to create the molds [7]. The tool is removed from the autoclave and immersed in water to finish the moldings. Precise control over the heating and cooling aspect ensures dimensionally accurate, smooth and strong molds [Anonymous, Aluminum Cylinder Block for General Motors Truck/SUV engines, A Design Study in Aluminum Casings, pp. 1-31.]. If the tool was not heated before the beads were injected, the results would be rough finishes in the molds with low-strength sections. If the tool and beads stay heated for an extended period of time, or is not cooled enough, the beads become overfused, which produces surface variations in the moldings. If the tool has been inadequately cooled, the molds will contain variations in dimensions [Anonymous, Aluminum Cylinder Block for General Motors Truck/SUV engines, A Design Study in Aluminum Casings, pp. 1-31.]. Figure 3 shows the final half stages of the lost foam casting method. . From Figure 3, once the individual molds are glued together, the assembly is placed in a vat with water-based ceramic liquid to prevent molten metal from destroying the mold, stiffen the assembly, and provide a smooth finish [Anonymous, Aluminum Cylinder Block for General Motors Truck/SUV engines, A Design Study in Aluminum Casings, pp. 1-31.]. The assembly can also be sprayed with the ceramic liquid, but is a time-consuming process. Next, the coated foam engine block is filled with sand,[13] compacted, and immersed in the molten metal alloy. Once cooled, sand is removed from the metal casting, cleaned, and undergoes heat treatment to increase the mechanical properties of the block. Finally, coolant and oil passages are machined into the block. Advantages over conventional sand casting: Unlike conventional sand casting, the lost foam process allows more complex and detailed passages and other features to be cast directly into the part. The lost foam process: 1) Forms complex internal passages and features without cores. 2) Reduces part mass with near net shape capability. 3) Eliminates parting lines. 4) Reduces machining operations and costs. 5)Provides for tight tolerances in critical areas and features. Lost Foam Casting for Fine Features: The lost foam casting process allows more complex and detailed passages and other features to be cast directly into the cylinder block. 1) In the cylinder block, oil galleries, crank case ventilation channels, oil drain back passages, and coolant passages are cast into the block. 2) These features would otherwise require drilling or external plumbing (with a potential for leaks). 3)Lost Foam castings have tighter dimensional tolerances compared to sand castings, because variations caused by core shift and core variability are eliminated and there is much less tool wear over the production life. The direct result is a significant reduction in machining costs and infrastructure investment and fewer opportunities for errors in machining and assembly. A comparison of green sand casting to lost foam casting shows a number of distinct advantages for lost foam: Property Green Sand Casting Lost Foam Casting Complex Internal Features and Part Consolidation Complexity determined by sand core limitations geometry, strength, and cost. Extensive and complex internal features (as small as 0.20) available in lost foam, based on detail duplication and pattern assembly in foam. Dimensional Tolerances +/- 0.030 is typical depending on part size, complexity, and geometry +/- 0.005-0.010 is typical depending on part size, complexity, and geometry. Surface Finish Capabilities 250-600 microinches typical. Depends on grain fineness of sand. 60-250 microinches typical. Depends on bead size and ceramic coating grain fineness. Feature Accuracy Core movement and shift between mold halves across the parting line limit feature accuracy. No cores or mold halves to shift and degrade feature accuracy Parting Line and Draft Angles Parting lines and draft angles are necessary for molding. No parting lines in the mold and minimal draft on tools. Environmental Costs Sand recovery requires binder removal and time consuming sand clean-up Sand is binder free, so it can be easily and rapidly recovered a

The Beatles :: Essay on The Beatles

The Beatles are even today known as the greatest and most influential act of the rock era. They introduced more innovations into popular music than any other rock band of the 20th century. Moreover, they were among the few artists of any genre that were simultaneously the best at what they did, and the most popular at what they did. They were also the first British rock group to achieve worldwide prominence, launching a British Invasion that made rock truly an international phenomenon. Guitarist and teenage rebel John Lennon got hooked on rock & roll in the mid-'50s, and formed a band, the Quarrymen, at his high school. Around mid-1957, the Quarrymen were joined by another guitarist, Paul McCartney. A bit later they were joined by another guitarist, George Harrison, a friend of McCartney's. As the line up of the Quarrymen grew and depleted, the Quarrymen were eventually reduced to the trio of guitarists: Lennon, McCartney and Harrison. The Quarrymen changed their name to the Silver Beatles in 1960, quickly dropping the "Silver" to become just the Beatles. Lennon's college friend Stuart Sutcliffe joined on bass, but finding a permanent drummer was a problem until Pete Best joined in 1960. Although the Beatles had "artfully combin[ed] the best of American musical influences , the vocal style of black rhythm and blues groups from the 1950s, the primitive excitement of rock 'n' roll, the flair of Elvis, and the slickness of the American "hit parade"" (Assayas, 26) they hadn't fully developed , and some of their early recordings were issued only after the band's rise to fame. Near the end of 1961, the Beatles' exploding local popularity caught the attention of local record store manager Brian Epstein, who was soon managing the band as well. He used his contacts to acquire a January 1, 1962, audition at Decca Records. After weeks of deliberation, Decca turned them down, as did several other British labels. Epstein's perseverance was finally rewarded with an audition for producer George Martin at Parlophone, an EMI subsidiary; Martin signed the Beatles in mid-1962. By this time, Epstein was grooming the band for national success by influencing them to get rid of their leather jackets and throw on a suit and tie.One more major change was kicking Pete Best out of the band. Best was replaced by Ringo Starr. As each of the groups singles sold over a million copies in the U.

Cultural Considerations Essay

This paper will examine and assesses the cultural concerns and influences of today’s societies with mixed cultures and the effect on the criminal justices system. The paper will address how the cultural concerns and influences affect justice and security administration and practice. The paper will show some contemporary methods by the police and security used in societies of mixed cultures. The paper will address how these influences and considerations relate to and affect nondiscrimination practices within the criminal justice system. Finally, the paper will address Sir Robert Peel’s nine principles and how they fit into today’s police departments. The military occupation of numerous countries in the Middle East and Europe has brought police practices into question. The local police forces have been trained by the military in which the rules are different. The free people are suffering abuse at the hands of the police in those countries. In those cases where militant law is present and security is more prevalent, the police appear to work more for the current occupying military than for that country’s government or the people. More than 200 cases of torture have either been investigated or court marshaled by the United States in violation of the United Nations anti-torture body in 2006. This increase in torture may be caused by racial, ethnic, and religious differences in the contemporary War on Terrorism (French &Wailes, 2008). The abuse on that scale does not occur within the United States; however, a problem still exists with the assessment of police and security personnel. These practices are scrutinized by the military, governments, security agencies, and local and foreign police. Of course, these practices question discrimination and profiling. Profiling is one of the major concerns here in the United States. Some confusion exits between profiling and racial profiling. A person cannot be profiled by a police officer based on color, sex, religion, or culture. However, a person can be profiled if he or she matches the description of a suspect. The measures currently used to assess officers are objective and may disclose intimate aspects of the person tested. The standard for recognition in the United States is the Commission on Accreditation for Law Enforcement Agencies (CALEA) that was established in 1979. Psychological testing is in place, however; standards are not set by CALEA, and each agency conducts their own testing (French & Wailes, 2008). In 1973, the National Advisory Commission on Criminal Justice Standards and Goals recommended that every police agency follow a formal selection process that includes a written test of mental ability or aptitude, an oral interview, a psychological examination, and a background investigation. It was believed that introducing greater screening and standardization to the selection process would result in a more qualified police force. International Association of Chiefs of Police (IACP) developed several guidelines for pre-employment psychological evaluations. These recommendations address such issues as validation of testing instruments, compliance with legislation, such as the Americans with Disabilities Act (ADA), using qualified psychologists familiar with the relevant research, and content of the written reports (Cochrane, Tett & Vandercreek, 2008). Compliance with such acts as the ADA indicates the implementation of diversity in the testing process. A few of the most common comprehensive personality tests given to police officers during their psychological testing include the following: Neuroticism, Extraversion, and Openness (NEO) Personality Inventory, Minnesota Multiphasic Personality Inventory–2(MMPI-2), and Inwald Personality Inventory (IPI). Traits from the NEO Personality Inventory–Revised, which was based on the five-factor model of personality, have also shown to be predictive of police performance. The MMPI-2 and the IPI have been shown to be effective in predicting several job criteria for police officers as well (Cochrane, Tett & Vandercreek, 2008). Today’s American policing and justice system is based on English principles and English common law. One such tradition was limited police authority. This gives way to liberties and freedoms and limits governmental authority. Another tradition was the localized police control as opposed to a national, centralized police force as experienced in many other countries. This turned out to be both an advantage and a detriment. The localization resulted in fragmentation and decentralization of law enforcement. The advantage was acquiring little national control (Walker & Katz, 2011, p. 24). Peel believed that prevention of crime could be accomplished without intruding into the lives of citizens so he developed the nine principles of community policing. His first concept was the basic mission of police was to prevent crime and disorder. The prevention of crime makes the job easier of the police. Police presence is deterrence, therefore prevents crime from occurring. This is the basis for today’s community policing concept. The public must also approve of the actions of the police in the performance of their duties. The people must work voluntarily with the police in observance of the laws to maintain public order (History, 2002). The public must comply voluntarily with the laws and work with the police. Most people do what is morally correct; in turn the police also must do what is lawfully correct. The police are directed by the United States Constitution and the Bill of Rights to safeguard every citizen’s right from interference from government. These philosophies are still observed today. If a citizen does not approve of the conduct of the police, a complaint is filed. If the public does not agree with a law, they work to make changes. If the public fails to observe the law, there are consequences, such an arrest or a fine. Another concept concerns the use of physical force to gain compliance. The public is cooperative with the police whereas physical force not need be employed. If compliance is not gained and physical force is required, the force will not be so great as to be considered excessive (History, 2002). The Constitution provides rights to the people and protects them from the police in this area. Laws in most states specifically write out what is considered â€Å"force,† when and how it can be used. Last, the police are specifically trained in the application of force through means of various weapons and hand to hand combat. This force is not to be excessive, not to be used as punishment, or in a punitive manner. The force used is that reasonable force to effect and arrest, to protect oneself or another from death or great bodily harm. The police serve both the public and the law, they shall not show impartiality, but to the law. The officers are also members of the public. Any interest the public has would also be interest to the police (History, 2002). In this case, the officer may come from any background may be either sex or any race. The officer must show fairness to members of other groups and not discriminate against those members or members of his or her own group. The officer shall treat everyone as equally as possible. The police are hired to uphold the law, at the same time serve the public. Peel’s theory indicates, when a conflict arises, the service to the law should outweigh the public service. This concept is contradictory to today’s practices. Policing has become â€Å"customer service†-oriented, where the customer is always right. The officers are members of the public, when they are in an off duty capacity, they are afforded the same rights as any other citizen. However, they should govern themselves as an upstanding citizen because they do represent the law. The final concept indicates the effectiveness of policing is the lack of crime and disorder. This concept is known as preventative policing. In today’s society, the crimes are not occurring where there is a high police presence. So, Peel’s principles are still used to some extent. The demographics have changed since his time. People and crimes have evolved. People’s values have changed, whereas they are tolerant of certain crimes. The attitudes toward police have changed. In a location where there is a strong police presence, fewer crimes occur. This is consistent with Peel’s concept. However, if the demographics of the neighborhood are less desirable, the people of the neighborhood indicate the police are prejudiced and do not want the police in the neighborhood. Thus, more crimes occur in this less protected neighborhood. If fewer police are present, the response time for an officer to an incident is longer because there are fewer officers and more calls. The ratio of officers to calls is higher. In these cases discrimination is blamed for the increased of police presence and the lack of it as well. The affected parties assume they are discriminated against because more police are in their areas, where more crime occurs. However, when the police are not present, they blame the police for the increase in crime because the police are not present. In conclusion, most of Sir Robert Peel’s principles can be applied to the organization of a police department today. In fact, many departments in England still work by his principles. Some need to be altered to accommodate today’s society to be more â€Å"customer† friendly. The United States Constitution and Bill of Rights need to be recognized, as well such as the Due Process Clauses to both the Fifth and Fourteenth Amendments if his principles are applied.

bio study guide questions Essays

bio study guide questions Essays bio study guide questions Essay bio study guide questions Essay Chapter: 20 Part: 1 of 1 Parts Major Topic(s) Covered: Unifying Concepts of Animal Structure and Function Read Additional Section(s): Individual Assignment(s): In class your group will be asked to answer the following question: The regulatory mechanisms that an organism uses result from an evolutionary process. Some organisms regulate their internal body temperature, and others do not. Make two suggestions as to what the evolutionary advantage might be for each of these two, quite different, lifestyles. Why this Material? Each of the living organisms on the planet Earth has evolved a istinctive body form (morphology) at a variety of levels: cellular, tissue. organ, whole animal. Yet we never should forget that it is the actual functioning of living matter at the these levels that that is at the heart of living processes. Thus, it is not possible to separate the analysis of an organisms structure from the functions that those structures carry out. And of course, evolutionary forces work on both structure and function. In this section we will look at common themes that we find in the structure- function relationships found in animals. Given the short evolutionary times (relative o the age of life on the planet) and the fact that all living things can be traced back to common ancestors, it will not be surprising that the arrangement and functioning of living systems is very similar in most animals. This section will also give us the opportunity to understand the control mechanisms necessary to maintain life and how organisms interact with their surroundings. While we will focus on animals, you might keep in mind how these principles and ideas will relate to the other large group of multicellular organisms the plants. We will have a chance to look at those ore closely in a few weeks. Learning Objectives: Upon completion of this learning guide, you should be able to: 1. Describe relationship between structure and function in an animal. Anatomy study of the form of an organisms structures Physiology study of the functions of those structures 2. Be able to define the terms: tissue, organ, and organ system and understand the hierarchy of animal structure. Tissue an integrated group of similar cells that perform a common function and structure Organ made up of two or more types of tissues that together perform a pecific task Organ system consists of multiple organs that together perform a vital body function 3. Know the major organ systems in the animal by being able to describe its function and the primary organs that make it up. ) circulatory delivers 02, nutrients to cells, transports C02 to lungs metabolic wastes to kidneys 2) respiratory exchanges gases w/ environment, supplies blood w/ 02 disposing of C02 3) integumentary protect body against physical injury, infection, excessive heat/cold, drying out 4) Skeletal supports body, protects organs, provides framework for muscles to produce movements 5) Urinary: digestive, respiratory, urinary and circulatory systems. 5. Explain what is meant by the term homeostasis and the mechanisms that organisms use to maintain this state. Homeostasis a steady state Homeostasis mechanisms regulate internal conditions, resulting in much smaller changes in the animals internal environment. Homeostasis depends on negative feedback: Control systems detect change and direct responses. Negative-feedback mechanisms keep internal variables fairly constant, with small fluctuations around set points. 6. Understand the meaning and use of the following terms or ideas: CT computed tomography (x-ray) PET Positron-emission tomography (glucose) MRI Magnetic Resonance Imaging (hydrogen atoms) Interstitial fluid solution that body cells are bathed with; exchange takes place through this fluid

Mass Media Creates Rather Than Reflects Social Reality Media Essay Essay Example

Mass Media Creates Rather Than Reflects Social Reality Media Essay Essay Example Mass Media Creates Rather Than Reflects Social Reality Media Essay Paper Mass Media Creates Rather Than Reflects Social Reality Media Essay Paper from e-mails to e-newspapers. This has made it so easy to pass on ; you could easy talk your head and even demo the universe what you ve got through YouTube ( Kuerschner, 2006, p.11 ) . When one is sitting in their life room to watch music picture from MTV, different readings arise, but one thing is common-MTV clearly displays the manner music has developed. MTV has by and large been a symbol of those who are immature and jaunty. The music, the life style of blame stars, stone stars, dad stars have liberally set new standards, which are seriously followed by the immature. MTV has increased its presence in oriental states ; this has been observed as an invasion from the West and a devastation of conventional values. There has been a creative activity of new styles of walking, speaking, vesture, and accordingly believing for the immature oriental heads. For illustration, MTV s epoch in Japan is rapidly associated with the birth of the rebellious Nipponese striplings. However, it is unfeignedly incorrect to believe that the MTV itself creates world from nowhere or to reason that the MTV is responsible for all alterations in the modern-day technologically advanced Japa n. The MTV has really been successful in the western universe, and so in the remainder of the universe merely because it has continued to back up and amplify the values that are inherently held and nurtured by these societies. The modern-day society is more broad, more self-generated, and more rebellious ; this may be as a consequence of industrialisation, and the media serves as an amplifier of such values. If the modern media would alternatively presume a more conservative figure, the expected consequence would be its extinction. ( Connell, 1995, p. 9 ) Information has a important consequence on people lives. For illustration watching the universe cup can do one to see a gamut of emotions, a sense of delectation, jitteriness and even bitterness at the same clip. Watching films can take person s head off from world ; this may convey inspiration to make move in a certain manner. Therefore, information has created a myriad of avenues to the society but at the same clip the society has become to a great extent dependent on these avenues ( Newbold et al. , 2002, p. 31 ) . The movie devising industry is another notable illustration. Several alterations have occurred in this industry and the modern cinematography industry has witnessed extremist alterations in the physical visual aspect of histrions and actresses. Main actresses have become symbols of beauty. Modern films depict beauty as tall and slim. More grounds can be seen from the modern postings and magazine screens display of images of adult females. The societal appetency and gustatory sensation for the adult female organic structure have truly changed over clip. The figure of a adult male is displayed as tall and good built ( Parenti 1990, p. 6 ) . The media has significantly propagated a certain type of beauty. Think about it this manner, what if the media starts to advance short and fat theoretical account of beauty, would it be successful? This inquiry may have more No than yes , this means a uncertainty in the ability of the media to make the beauty that is non inherently held by the soc iety. Another illustration is watching a film of the hero robbing a bank with dramatic inventiveness ; this instills negative messages into the multitudes ( McGillion, C. , 2003, p. 33 ) . Generally stealing is incorrect, but the hero of the film walks out free, and goes to hold fun without any scruples. Such films create negative values that are against the rules of honestness ( Barr, 2000, para.2 ) . However, the media plays a important function in showing facts and worlds say from newspapers on development, finance, justness, poorness, e.t.c, which are existent contemplations of what is go oning in the society ( Newbold, 2002, pp. 219 ) . The values and outlook of the society is displayed as a whole instead than as an person. Renowned scholar James Curran argued that The strong belief aˆÂ ¦ that the media are of import bureaus of influence is loosely right. However, the ways in which the media exert influence are complex and contingent ( p. 158 ) . For illustration the manner the media has reported on terrorist act has truly instilled fright in the heads of people ( Cozens, 2006 ) . The abhorrence of terrorist act has on the other manus turned others into pacificist. The media is arguably the most of import signifier of showing positions and it is itself a potpourri of person s and society s positions ( Fiske 1989, p. 127 ) . With all these said, some view the media as being broad but a closer analysis reveals otherwise, the proprietors of media mercantile establishments are non broad themselves. Media mercantile establishments are concerns that are kept afloat by advertisement grosss. It is true that some media mercantile establishments do a good occupation of being impartial. But when a Television station backs a political campaigner who is sponsored by concern heavy weights it must pay the monetary value ( Kalathi, S, 2004, p.40 ) . Money of class straight buys influence as a consequence it affects how media covers a certain event ( Price, 2002, p. 13 ) . It is a medium for the opinion category to perpetuate their power, wealth and position ( Barr, 2000, p. 17 ) . Therefore, the media in this sense does non reflect world ( Curran, 2002, p. 45 ) . Decision The thesis of this paper is that the media does play a function in making world from underlying social values. Therefore, the media can non make values of its ain. The article puts the comparative advantage and disadvantage of the power of the media in making world, with an accent on the manner the society has inherently allowed this to go on.

The aims and Proposed plan of work Essay Example | Topics and Well Written Essays - 1000 words

The aims and Proposed plan of work - Essay Example Proposed plan of work, including its relationship to previous work, with key references. Please avoid excessive use of technical terms, however if unavoidable provide a glossary of terms as indicated in section 4.5. (Please only use the space provided below – no more than 1,000 words and written for a non specialist audience. References may be attached on a separate sheet): To achieve the aims of this thesis, the researcher conducted an analysis of three relevant arbitration laws: the new Saudi Arbitration Law 2012; the former Saudi Arbitration Law 1983; and, the English Arbitration Act 1996 (attached). The researcher is of the opinion that this will establish a clear framework by which the research questions can be addressed since these are the main legal sources of both Saudi and English arbitration jurisdictions. The structure of this study follows a logical approach, beginning with the legal basis of arbitration as represented in the arbitration agreement. It is followed b y the discussion of the arbitral tribunal, which oversees the arbitral process, issues arbitral decision and decide on the arbitral award. Finally, a section will be devoted to third and last stage in the process, which is the outcome of the arbitral process: the arbitral award and its enforcement. The supervisory team suggested to begin the study with the discussion and analysis of the Qualifications of Arbitrator. The reason for this is that the arbitrator qualifications constitute the fundamental framework that outlines the limitations of freedom for parties to arbitration in the selection of arbitral tribunal. Presently, the arbitration agreement is being analyzed and examined. This will include the validity and scope of arbitration agreement, which is expected to shed light on the extent of freedom of parties to arbitration in terms of drafting an arbitration agreement to resolve either standing disputes between them or those that may arise in the future. The next section will concentrate on the extent of freedom of arbitration parties and the arbitral tribunal regarding the selection of procedural rules and substantive law under: 1) SAL 2012; 2) Sharia, as it is considered the applicable law in Saudi; and, 3) under the EAA 1996. In addition, key issues will also be analyzed including the controversial application of the Sharia law such the concepts of Riba and the loss of future profits, in addition to the extent of differences in the viewpoints within Sharia in case one or both of arbitration parties are religiously neutral. The third section will be devoted to the discussion of the arbitral tribunal. This will undertaken by analyzing three important factors: duties, powers and jurisdictions of the arbitral tribunal. Again, this will be carried out in the context of Sharia and SAL 2012, and in comparison with the EAA 1996 and the case laws in the UK. The final stage (PhD) will include the role of national courts and their impact on the success of the ar bitral process. This will be divided into three sections. The first section will analytically and critically examine the role of national courts in the arbitral process in the commencement of and during the arbitral process under the two Saudi and English jurisdictions. Second section will deal with the concept of arbitral award and

Homework 4 Assignment Example | Topics and Well Written Essays - 250 words - 2

Homework 4 - Assignment Example When the first rocket was launched, it made us aware that the world is limited in its resources and space. There is a limit to the amount of life the earth can hold. The destruction to the environment by humanity presents new challenges that plants and animals have adapted. However, the destruction has reached an extreme scale. Species there are over one and a half billion that have been discovered by scientists. There is just a small representation of the diversity of animals that exists all over the world. Most people just appreciate the big animals like elephants. Lions in the savannahs but there are also a great diversity of small animals like mosquitoes, the sea holds so much life beneath it, but most of it remains a mystery. There are many cases of extinction on the face of the planet of big animals but if small animals were to be extinct, the world would face a crisis as they form the foundations of the earth. Extinction has become massive on a scale of 100 t0 1000 due to human activities like deforestation. Is there an importance to preserve our biodiversity. The answer is yes. The eco-environment provides us with soil and cleanses our air all free. Most importantly, we should focus on handing down an environment full of rich biodiversity to the next