Movie Review Example | Topics and Well Written Essays - 1500 words

Movie Review Example The movie, which has a historical setting notably the Second World War, shares the same ideology as the events that took place between 1942 and 1943 when constructing Burma Railway. In the movie, British prisoners set out to serve their sentence at a camp that was controlled by Japanese soldiers. Upon arrival, however, the commander in charge of the camp brings to their attention that all the prisoners are to take part in the construction of the bridge along river Kwai. The Colonel in charge of the British soldiers however does not support this ideology. Colonel Nicholson holds the opinion that the Geneva Convention prohibits his team of British prisoners from taking part in such activities and orders his team not to take part in such activities. The ideological differences held by the leaders of the two camps leads to a lot of rivalry within the camp, with both the British prisoners and Nicholson their Lieutenant being punished by Commander Shears. Nicholson is locked up while his troops are forced to withstand the strong heat brought about by the prevailing harsh weather conditions. In a sudden change of events . Nevertheless, Commander Shears pardons Nicholson. Motivated by the spirit of getting it right, Lieutenant Nicholson orders his troops to restart the construction of the bridge along river Kwai as portion of the work that had been done is not worth. Soon after the construction work has been completed, the Major Warden and Lieutenant Joyce plot a ploy to destroy the bridge. To help them in accomplishing their task they plot explosives and several wires under the bridge. Luck does not however go their way as the water levels reduce exposing the explosives under the bridge. Lieutenant Nicholson and Colonel Saito join hands, and amidst the prevailing circumstances, they manage to prevent Lieutenant Joyce from reaching the explosives. While going through the movie,

MKT DB 10 Essay Example | Topics and Well Written Essays - 500 words

MKT DB 10 - Essay Example To this extent, I have gained immense experience on how superior branding and advertising through online marketing channels help in creating new market niches within a short period. Online marketing is a fascinating segment of this project as it applies in tandem with the level of the globalization. I would like to learn on how several online marketing instruments can make can be integrated into the management system to enhance direct management decision making that pertains the consumers. This is segment is intrusting because the integration is a result of the high class flexibility of the online marketing strategies, which make it easy to mould an online platform that can address specific issues relative to a specific market niche. Studying such instruments and the whole process of integration forms the base of my urge to pursue further the marketing segment, particularly, the online one. On equal measure, the skill of understanding the essence of application of specific strategies on particular stages of the product life cycle is critical in ensuring the smooth product movement from one stage to another with an aim of realizing considerable profit margin and keeping watch of the competitors in the market. I have gained much in-depth understanding on this skill and I believe I can develop a product from the very first stage of development to the last stage of declining with the application of the relevant marketing strategies as indicated in the table that follows. This involves the creation of a new idea and extensive investments in areas of research and product development. The relevant marketing strategy in this stage involves assessment of the feasibility of the project and the anticipated target audience. In addition, the anticipated market share relative to the existing market share should be evaluated (Mackenzie, 2007). This involves the launching of the product. Since the Kick

The Abrasive Jet Machining Engineering Essay

The Abrasive Jet Machining Engineering Essay Abrasive Jet machining is a kind of blasting process and one of the most hopeful micro machining process for hard and brittle materials like glasses and ceramics. Metal is removed due to the erosion caused by impact of high speed abrasive jet. Abrasive Jet machine has precision X-Y axis rigidly mounted to the cutting table and it has programmable Z axis with nozzle assembly. According to the proper design calculations we can select different components of Abrasive Jet Machine. In this project, I develop the model using different CAD packages like AUTO CAD and SOLID WORKS. Moreover I also explain the effect of several AJM operating parameters like standoff distance, size and type of abrasives on metal removal rate of AJM. I explain how we can maximize the efficiency of AJM by controlling their parameters. In this model care has been taken that use less fabricated component rather than directly procuring them because sometimes we find less accuracy in fabricated component so performance of machine can be low. Introduction of Abrasive Jet Machining Material removal processes is a part of manufacturing process and it can be divided into two major groups. One is conventional machining processes and another is Non- conventional machining processes. Different types of Conventional machining processes are Milling, Shaping, Drilling, Slotting, Boring, etc. And the examples of Non Conventional Processes are Abrasive Jet Machining (AJM), Electro-Discharge Machining (EDM), Laser Beam Machining (lBM), Abrasive Water Jet Machining (AWJM) etc.. Abrasive jet machining also called, Abrasive Micro blasting, it is a material removing process and material is removed by a focused steam of abrasive particles carried by high pressure gas or air. A fine abrasive particle strikes on work surface through nozzle and the material is removed by erosion by the high velocity abrasive particle. AJM is used mainly to cut materials that are very sensitive to heat damage and thin section of hard materials that chip easily and it is also used to cut intricate shapes and holes which are more difficult to produce by other processes. Equipments of Abrasive Jet Machine C:UsersVishalDesktoppart01.jpg A layout of Abrasive Jet Machining is shown in fig. Abrasive particles are fed from the hoper into the mixing chamber. High pressure air or gas (such as Carbon Di-oxide or Nitrogen) used as carrier gas is supplied to the mixing chamber which containing abrasive powder and vibrating at 50 c/s. with the help of pressure regulator we can control the gas flow and pressure. The high pressure air/gas entrains the abrasive particles and this mixture comes out from small nozzle at high velocity. This stream of abrasive particles strikes on the surface of work-piece and cut the material. The abrasive stream is directed to the work piece locations by nozzle, which may be manually positioned or mounted in some designed fixture for automatic operation. For automatic operation, cam drives, tracer mechanism or pantographs used to automatically position either nozzle or work piece. Abrasive Jet Machining Mechanism: C:UsersVishalDesktopAjm set up 3d.jpg In this process kinetic energy of abrasive jet is strike on the surface of work piece then it converts into pressure energy. If pressure energy is more than the yield strength or tensile strength of work piece material then material gets cut. List of Components of AJM: Abrasive Delivery System ( Including Hopper) Pressure Regulator Air filter valve Mixer Nozzle Suitable arrangement to hold the work piece Elements of Abrasive Jet Machine There are three main elements of AJM: Nozzle Abrasive Carrier gas The above mentioned three elements of AJM influence: Material removal rate and accuracy of machining Nozzle wear rate Surface roughness Geometry of cut Variables in Abrasive Jet Machine The process can be easily controlled to vary the metal removal rate which Depends on following variables. Nozzle design ( mean Shape of nozzle such as circular, square) Distance between the nozzle and work piece Inclination to the work surface Type of abrasive Size and shape of abrasive Flow rate of abrasive Type of carrier gases Velocity of abrasive jet Work piece material Nozzle design: Nozzle must be resistant under different conditions like pressure and kinetic energy of jet and common materials used for nozzle are tungsten carbide and synthetic sapphire. Pressure losses at the end of nozzle should be low. Distance between nozzle and work piece: Standoff distance affect on material removal rate of AJM. Material removal rate is increase if we increase standoff distance up to certain limit and then fall gradually. Small standoff distance gives better penetration of abrasive particle into the work piece and large standoff distance might cause flaring. Successfully experiments show that effective standoff distance is 0.8mm. Types of abrasive: Aluminum oxide is preferable abrasive in majority of application and silicon carbide abrasive also use in certain cases. Abrasive size also prominent factor in AJM. Best results have been obtained with a abrasive size in the range of 10-50  µm. Abrasive Flow Rate: Maximum material removal rate is achieved with a flow rate at 8-18 g/m. Increase the flow rate above the normal range for a particular nozzle design results in lower stream velocity thus decrease the material removal rate. It is advisable to use acceptable flow rate to conserve abrasives and increase the nozzle life. Grain size: Abrasives with smaller grain size have high density which may cause chocking problem of nozzle. General grain size use in AJM is 10 µ to 50 µ. Fine grains are used for polishing and deburring. Coarse grain size cut faster and cut deeper also. Work piece material: Abrasive jet Machine is generally used for machining brittle material like ceramics and glass and effect of MRR is depends on hardness of material if hardness is high then MRR is low and vice versa. Advantages of Abrasive Jet Machine: Low capital cost Low power consumption Ability to cut intricate shapes in high hardness and toughness material Ability to cut fragile and heat sensitive material without damage because no heat generated and overall forces are low The part produced is free of burs It is flexible process from design point of view Tooling time is substantially reduced Both faces of work piece can be machined simultaneously. Disadvantages of Abrasive Jet Machine It is slow process since metal removal rate is very slow. Larger floor space is required Skilled operators are needed Sharp corner cannot be produced High manufacturing cost Material thickness that can be machined is limited Abrasive grains can stick into soft material so cleaning is required High wear rate of nozzle The process tends to pollute the environment Applications of Abrasive Jet Machine Removing flash and parting lines form the injection molding machine Deburring and polishing plastic components like nylon and Teflon Frosting interior surface of glass tubes Etching marking on glass cylinder High quality surface can be easily produced Glue, paints can be removed effectively form paintings. Different Components of Abrasive Jet Machining set up Abrasive Delivery System CNC Control System Pump Nozzle Different Motion System of Nozzle Catcher plate Abrasive Delivery System: Modern abrasive delivery feed system do not need a vibratory feeders and other metering valves. For smooth and precision cutting operation we need to have fixed and continuous abrasive flow rate. Now days we use orifice metering system metering system which is very reliable and extremely repeatable. During machining set up, once we measured the abrasive flow rate through orifice we can enter that value in control computer programmed and then no adjustment or further tuning of abrasive flow is ever be required. Bulk abrasive delivery system is mounted with the wheel and it is also easy to move and this kind of system is use compressed air to transport garnet from the bulk abrasive hopper to small hopper attached with the machine. Features: can hold approximately 550lbs abrasive Can be located 20 feet away from the Abrasive Jet machine. Height and Width are of following: 1320mm and 960mm Can handle minimum pressure 80 to 95 psi. How it works: Abrasive particles are stored into the hopper and abrasive container has one inlet and one outlet for air passage. The flow rate of abrasive is controlled by rotational speed of motor. Due to rotation of cam, abrasive container gets vibration. The abrasive particle is delivered by rotation of cam and motor arrangement. C:UsersVishalDesktophopper 3d.jpg C:UsersVishalDesktopAbarsive hopper.jpg Control System for Abrasive Water jet Machine: Most of abrasive water jet machine equipped with the CNC control system. G code programming is installed in CNC machine. But the limitations of the G code Controller is that feed rate is held at constant speed and feed rate varies only for some regions like curves and corners. Another limitation of G code controller is that is used for rigid cutting tools. Abrasive water jet machine is not a kind of rigid cutting tool. Every time change the feed rate for curves and corner results in uneven cut. So by considering various parameters like parameters of nozzle and intricate shape of part and variable thickness of the work piece and materials going to cut help to determine the feed rate so that operation can be done smoothly. For that we have to prepare the control algorithm which compute the desired feed rate based on the above parameters. By using G code we can convert this feed rate mechanism into a actual programming. This programming help to drive the servomotors and that controls the X Y motion and this way we can make part with more precision. Pump: Two type of pumps used in the Abrasive water jet system. One is Crankshaft pump which was used in old technology buy nowadays for high pressure cutting technology intensifier pump is used. In this hydraulic power pack system is a type of positive displacement pump. This system drives the intensifier. Hydraulic power pack system is controlled by microcomputers to set up the pressure etc†¦ Electric motor is used to drive the hydraulic pump and as the hydraulic fluid push the large cylinder which generate the high force on small cylinder and this small cylinder pressurize the water at the level which is proportional to the cross section area of larger cylinder to the small cylinder. Nozzle: High pressure water flows into the nozzle and cutting head of nozzle which comprise of an orifice and mixing chamber and an insert where water jet mixed with the abrasive and form an abrasive water jet. Various motion of the nozzle is controlled by motion system across the material. C:UsersVishalDesktopnozzle01.jpg How water jet Forms: Typical diameter of the nozzle is 6mm. High pressure water is then fed into the pipe which can carry the water at 400 Mpa and consisting of different joints without any leakage between them. When water passes through the orifice flow of water convert onto narrow jet and orifice diameter is usually about 0.2 to 0.4mm. When water enters into the cutting head section pressure head of water is converted into velocity head. Velocity of water can be expressed as Vw = 2Pw / Ï w. Where Pw is the pressure of water and Ï w is density of the water. The orifice usually made of sapphire and life of the orifice is about 100-150 hours. From orifice narrow water jet passes through the small section vacuum is created in mixing chamber and that pulls abrasive particles and air into the mixing chamber. Abrasive particles are feed through the different techniques like Vibratory bowl or Belt feeder. Mixing Chamber: Mixing tube is the section where abrasive particles mixed with the water jet. Focusing tube generally made of tungsten carbide because of its good abrasive resistance characteristics. Focusing tube has inner diameter typical about 0.8 to 1.6mm and length of 50 t0 80 mm. To get the maximum accuracy we have to replace the mixing tube frequently. We can replace it when tolerance goes below the acceptable level. Numerical modeling of Mixing process can be described as of follow: If we consider some energy losses at the water jet formation at the end of orifice then water jet velocity described as of following way: Vw = ÃŽ ¦ √ (2Pw/ Ï w) Where ÃŽ ¦ is Velocity coefficient of the orifice. Volume flow rate of water can be expressed as following: Qw = ÃŽ ¨ x Area of orifice x Vw = ÃŽ ¨ x à °Ã‚ Ã…“ «/4 do ² x ÃŽ ¦ √ (2Pw/ Ï w) = Cd x à °Ã‚ Ã…“ « /4 do ² x √ (2Pw/ Ï w) Where ÃŽ ¨ = co efficient of Vena Contracta Cd = Discharge co efficient of orifice. So total power of the water jet can be expressed by Pw = Qw x Pw = = Cd x à °Ã‚ Ã…“ « /4 do ² x √ (2Pw ³/ Ï w) Due to the loss occur in the mixing process both momentum and energy is not conserved. But assumed that no looses occur in momentum at initially. So ÃŽ £ (à ¡Ã‚ ¹Ã‚  x v) before = ÃŽ £ (à ¡Ã‚ ¹Ã‚  x v)After (à ¡Ã‚ ¹Ã‚ airvair + à ¡Ã‚ ¹Ã‚ wvw + à ¡Ã‚ ¹Ã‚ ava)before = ( à ¡Ã‚ ¹Ã‚ aivairr + à ¡Ã‚ ¹Ã‚ wvw + à ¡Ã‚ ¹Ã‚ ava)After As we know that air has very low density so momentum of air, before and after are neglected. Consider one more assumption and is that after mixing abrasive particle has same velocity of water and also neglect the momentum of abrasive then above equation can be expressed by à ¡Ã‚ ¹Ã‚ wvw = ( à ¡Ã‚ ¹Ã‚ w + à ¡Ã‚ ¹Ã‚ a) vaw So vaw = [(1/(1 + R) ] x vw Where R is the loading factor = à ¡Ã‚ ¹Ã‚ a/ à ¡Ã‚ ¹Ã‚ w During mixing process momentum losses occur due to the friction between the abrasive particle and inner wall of focusing tube and collision between the abrasive particle and water jet so for time being consider momentum losses and then equation is described by V aw = ÃŽ · x [(1/(1 + R) ] x vw Where ÃŽ · is the momentum loss factor. Motion System: Motion system can be designed in many ways according to the motion of nozzle around a work piece. This mechanism provides excellent operating conditions for the operator. C:UsersVishalDesktop3dTable 3Imagetable1.jpg Materials are loaded with the help of overhead crane or fork lift truck to the tank. This mechanism is useful for 5 axis tables and also provides pretty much space to the vertical tilted axis. This structure has restriction to the movement of nozzle that means movement of nozzle has limitation to twist and long distance between the table and work piece result in error due to the deflection of machine. In this type of mechanism, Nozzle is mounted to the Y axis carriage. C:UsersVishalDesktop3dTable 3Imagetable 2.jpg Y axis is moving beam and is mounted with the X axis. Back beam is supported at the two ends. This mechanism is suitable for very large machine. C:UsersVishalDesktop3dTable 3Imagetable 3.jpg In above mechanism, nozzle is very close to the plane of work piece which minimize static and dynamic errors while operation is going on. This system is not suitable for manually material loading and this provide material loading is equal to the access of the tank. Cost estimation ( Bill of material) Item Cost per single item No of items required Total cost Linear motion guide ways hsr30cm $385 3 $1155 Precision Ball screw $188 3 $564 Supporting Unit $144 3 $432 Frl unit air filter $48 1 $48 Diamond nozzle for long service life $900 1 $900 Abrasive hopper with 90lb capacity $132 1 $132 Other accessories $250 $250 Total $3481 Material Removal rate Mechanism and Modeling in Abrasive Jet Machining As we discussed earlier, material removal rate takes place in abrasive jet machining because of the erosion of the work material and erosion take place due to the high impact of jet velocity strikes on the work piece. Following assumption has been considered in mechanism of Material removal rate. Shapes of the abrasives are spherical and abrasive particles are rigid. Kinetic energy of the abrasive particles is fully used in removing material of the work piece. Erosion takes place in brittle material due to the brittle fracture and the volume of fracture is considered as hemispherical with the diameter which is equal to length of the indentation. C:UsersVishalDesktopGeometry.jpg C:UsersVishalDesktopPart2.jpg From the geometry of the erosion of material DE ² = DF ² + EF ² EF ² = r ² = DE ² DF ² r ² = (dg/2) ² (dg/2 H)  ² = -H ² + dg H ≅ dg H r = Volume of the erosion of material is equal to the volume of hemispherical crater and is given by: TB = 2/3 = 2/3 x (dg H) ^3/2 As we know kinetic energy equation is given by  ½ mv ² so the kinetic energy of Abrasive particle grit is given by K.Eg =  ½ mg V ² = /12 x dg Ï g V ² Where V = Velocity of Abrasive Particle Ï g = Density of Abrasive Grit dg = Diameter of Single Abrasive Grit mg = Mass of Abrasive Grit When Abrasive particle strikes on Work piece material, work piece will be subjected to maximum forces which cause the erosion of material which I indicated in figure by symbol H. Therefore work done is given by W =  ½ x F H Impact force F is give by F = Indentation Area x hardness of the material W =  ½ x r ² H S And Work done is equal to Kinetic energy because we assumed that kinetic energy is fully utilized for material removal so W = Kinetic energy K.E  ½ x r ² H = = /12 x dg Ï g V ² So H = (dg Ï g V ²)/ (6r ²S) = dg V (Ï g/6S) ^1/2 Now material removal rate of brittle material can be expressed as of following: MrrB = TB x No. of strikes by abrasive grits per second N = TB x (ma/ /6 dg Ï g) = (6TB ma/ dg Ï g ) Now Put the value of TB = 2/3 x (dg H) ^3/2 = [ 6 x (2/3 x (dg H) ^3/2) x ma] / ( dg Ï g ) = (4 ma Ï g) x (H/dg) ^3/2 As we know that H = dg V (Ï g/6S) ^1/2 So MrrB = (4ma/ Ï g) x (dgV/dg) ^3/2) x (Ï g/6H) ^3/4 = (4maV) ^3/2 / (6^3/4 x Ï g^1/4 x S ^3/4) = (maV^3/2) / (Ï g^1/4 x S^3/4) Fabrication and Assembly of Abrasive Jet Machine Nozzle: A standard length of cylindrical rod typically made of Tungsten Carbide or Synthetic Sapphire or MS was cut into the proper length based on the requirements by using power hack saw. By turning process in Lathe machine we can reduced the diameter of cylindrical rod and bring up to 15mm. On same lathe machine we can make tip by Taper turning process by tapering one end of cylindrical rod. Then make a blind hole of 20mm on planner face of rod by using 12mm drill bit in drilling machine. Due to the tool tip angel, a shape of 118 degree formed at the end of blind hole. To get the 1mm of Tip of nozzle, we can use the 0.74mm drill bit in Drilling process. Cam: Mild steel of 40mm diameter can be used as a raw material of Cam. Turning process is used to bring down the diameter up to 35mm. By using power hack saw we can get the required width (Approximate 25mm). Then both cut faces can be machined in Milling Machine. Through hole can be made by 16mm Drill Bit in Drilling Machine. Abrasive Container: Abrasive container usually made out of the hollow cylinder. On the both end of container two Cast Iron plates were welded. On the top plate, two iron pipes fitted through the holes. There are two pipes in a system, one is inlet which is longer and makes more agitation of abrasive particles and outlet pipe is shorter. Compressed air goes to the abrasive container through inlet pipe and mixed with the abrasive particles then mixture of Air and Abrasive forward to the nozzle to perform operation Vibrator Assembly: Angel section is welded with the base plate by welding process. Induction motor is placed on the angle section which is parallel to the base plate. Induction motor is tightening with the nut and bolt with base plate. Cam is fixed with motor shaft and Abrasive container is connected to the rod and it is freely to rotate around the rod. C:UsersVishalDesktopVribator.jpg Design data and Technical Specification of Various Components: X-Y Table X -Y table is prominent part of the abrasive water jet machine. Various fixturing arrangements have to be provided to hold the work piece while operation is running. The travel of X-Y table has been decided based on the application. Table consists of two parts. One is upper plate and another one is lower plate. Upper table travel in X direction and lower table travel in Y direction. Based the model of Omax 2626, table can travel 730mm x 660mm. Y Axis is responsible for movement of work piece in Y direction. Other components of X-Y are of following. Linear motion guide way Recalculating ball screw Supporting unit for ball screw Couplings Nuts and bolts Other components as required Linear motion guide way: General application of linear motion guide is for the linear motion. Based on the different parameters like travel length, floor space requirement, type of equipment being used, linear motion guide way is selected. With the help of different rollers which provide rolling elements between the rails and block we can get higher precision linear motion system. Frictional losses are reduced between the elements by restraint effects between the rails and block and it can withstand high load in any directions. Assembly of Linear motion Guide way Source: Hiwin linear motion guide way catalog_G99TE13-0809 C:UsersVishalDesktopl m guide way.JPG L M Guide way with Dimensions Structure of linear motion guide way: As shown in fig, each raw of balls have angle contact 45 degree. Retainer plate has facility to hold the recalculating ball screw which guide linear motion guide way in directions. End plate is attached with the linear motion blocks which allow the balls to circulate. Side seal is placed between the row of balls and grease nipple is attached with the end plate. Linear motion guide way can achieve precise motion by setting up the section height smaller as much as possible based on the requirements and also provide rigidity of the model. Compare to all others traditional slides, co efficient of friction of linear motion guide way is 1/50 th. Advantages of linear motion guide way: Provide high accuracy Insufficient lubrications in traditional slides give errors in accuracy and in linear motion guide way frictional contact is rolling contact so it has little wear and therefore it has long life. Due to small frictional resistance a small driving force required to move the load and hence it provides high speed of motion. Provide Equal loads capacity in all four direction Best advantage is the interchangeability of the parts. Ball Screw: Ball screw assembly for linear motion guide way consists of screw and nuts. Helical threads or grooves provided between nuts and screws and balls are rotate between them. Ball return system provides the way to return the balls again that means when ball reach at the end of the nut it return through the return pipe. Ball nuts in ball screw assembly determine the fatigue failure in the system and ratios of number of threads in ball nut to the number of threads on ball screw decide the wear out. By considering the table length, calculation of X axis and Y axis ball screw length is determined. For our table our X axis ball screw length should be 730mm + 200 mm (Breadth for upper table) + 100mm allowances for below cover so it should be 1030mm. For Y axis table it should be 660mm + 200mm + 100mm so it should be 960mm. Based on the ball screw length, rail length is determined and which is 50mm larger than ball screw length. C:UsersVishalDesktopball screw.JPG Ball screw Assembly Supporting Units: Ball screw supported bearing are designed with the high bearing stiffness compare to other conventional bearing. Two kinds of supports are available fixed end support unit and supported end support unit. In fixed end support unit can take all thrust by given work and in another support end support unit acts like usual bearing. Nut bracket is used to bolt the ball screw nut with the work load platform. Vertical motion Module: Vertical motion module comprise of all above components like L M guide way, Pipe holder , Ball screw assemble, supporting units, nozzle holder and nozzle etc. This assembly is used for adjustment of stand of distance between nozzle and work piece. C:UsersVishalDesktopVerticle motion module.jpg Fixture arrangement for work piece in Abrasive Jet Machine As abrasive jet machine is used for various kind of applications that also result in various fixture arrangement of work piece based on the application. So not only one application can use for the applications. Usually Abrasive jet machine requires less fixturing equipment to get start the operation so combination of different components can be used for particular kind of work. Fixture is used to locate the work piece correctly and for quick loading to reduce the machining cycle time. To prevent undesirable movement or rotation of work piece while the work piece is under the process. When work piece is under the processes, high pressure of water and abrasive strikes on the work piece so it can move in sideways or lift up those results in errors. Most of abrasive jets are used to make flat parts or add some features to the existing parts. So for all kind of flat parts 3 parameters has to considered and which are X position , Y- position and angle of rotation with respect to X-Y point. Figure shows the fixture arrangement of work piece for flat parts using square and clamps. As shown in figure parts are lying on the slats and clamping is provided to prevent the side motion of work piece because slats do not provide better support to the work piece. A square plate is bolted with the tank. As shown in fig. Screws which are close to the work piece is a clamping screws and which are far from the work piece for the square to adjust the different thickness of material. This system is used to prevent the rotating motion of slats. Comparison of Abrasive jet Machining process with other Processes: Abrasive Jet machine Vs Laser Beam Machining: Comparison with respect to the material can be cut: Abrasive water jet can cut varieties of material with good conditions compare to laser beam machining. For refractory materials, laser beam machining has poor applicability whereas abrasive water jet has good applicability for same materials. Capital cost and abrasive water jet set up is very low compare to Laser machining. There is no heat produce in Abrasive water jet marching so it minimize the thermal distortion of material also minimize the secondary operation because it provides continuous or uniform smooth surface with little burr on the surface. As the thickness of the work piece increase, higher precision can be obtained by abrasive jet machine with the same or higher tolerance than laser. Abrasive water jets are safer compare to laser machining and abrasive jet nozzle is very simple than laser however life of nozzle is about 100-150 hours of operation. However there are some disadvantages associated with the abrasive water jet process while compare with the laser machining like tool wear is very low and power consumption also very low in laser machining as abrasive water jet has little high compare to laser. Abrasive water jet machine or Abrasive jet machine Vs. EDM. EDM has low applicability for the material like super alloys whereas abrasive water jet machining has good applicability of the same materials. Abrasive water jet machining has facility to make piercing in the parts by itself while EDM process has required pre drilled hole. There is no heat affected zone so this process eliminates secondary operations. Good capabilities to make large parts with economical cost. Rapid software programming which is very simple and less set up with fixturing make this machine considerable to buyers. It can work better in any kind of materials like conductive or non conductive. If the thickness of work piece is less than the 25mm or 1 inch, abrasive jet machine works five to eight times faster than the EDM but less precise as well. Abrasive water jets Vs Plasma Material removal rate efficiency of plasma machining is very low compare to the abrasive water jet machining. Plasma machining is not preferable to refractory material while abrasive water jet machining applicable to wide range of materials. Abrasive water jet provides better edge finish than plasma machining process but plasma machining process is faster than the Abrasive water jet process. Abrasive water jet Vs. Milling Milling can be used for rapid production if set up is already done and fully programmed whereas abrasive jet machining has rapid programming feature and if operator is well trained than set up do not required for the part. Minimal burring problem, less scrap, environmentally friendly, no oil soaked chips are the reasons of abrasive jet machining which replacing milling process in machine shops.

Cocaine :: essays research papers fc

  Ã‚  Ã‚  Ã‚  Ã‚  For many centuries people have used different drugs for various reasons. Depending on which decade you are in there are particular drugs of preference and abundant usage. Cocaine is most commonly used among 18-25 year olds rather then other age groups. I chose cocaine because it is what effects people my age most commonly.   Ã‚  Ã‚  Ã‚  Ã‚  Cocaine was first used in the late 1800’s as a local anesthetic during surgeries. Cocaine is considered the most potent stimulant of natural origin. Cocaine can be used in many different ways. Snorting cocaine is the quickest way to use the drug. The drug is snorted through the nose and absorbed by the nasal tissues and spread through the blood stream. The quickest way to feel the impact of the drug is through injection. The drug is directly injected into the bloodstream causing immediate effects. The last way is inhalation. Cocaine can also be smoked by which it is inhaled into the lungs then into the bloodstream. Inhalation can be as rapid as injection. Another form of cocaine is known as crack. Crack is processed with ammonia or baking soda and water; it is then heated to a smoke able consistency.   Ã‚  Ã‚  Ã‚  Ã‚  According to Office of National Drug Control Policy (ONDCP) in 2002 there were an estimated 1,059,000 new cocaine users in the United States. The average age of those who first used cocaine during the year was 20.3 years. Sadly in 2003-2004 approximately 34.9 million Americans over age 12 had tried cocaine at least once. The numbers are sad and shocking but amazingly continue to increase throughout the years.   Ã‚  Ã‚  Ã‚  Ã‚  Many health factors and risks arise with the use of cocaine. Cocaine is a central nervous system stimulant. Physical effects of cocaine use include constricted blood vessels and increased temperature, heart rate, dilated pupils, increased energy and increased blood pressure. Cocaine use in its early stages is often hard to detect. Some of the signs of possible cocaine use are, nosebleeds, lose of appetite, stealing from loved ones for money, and lying. A cocaine user, once dependant, will experience stomach cramps, increased heart rate and random cold sweats. Some other long-term effects of the use of cocaine are paranoia, irritability, restlessness, auditory hallucinations, mood disturbances and many others. Users may also experience feelings of restlessness, irritability, and anxiety (NIDA). Many people who inhale the drug may suffer from acute respiratory problems including coughing, shortness of breath, and severe chest pains with lung trauma and bleeding.

Mass Media in Your Pocket or Purse Essay

We are in a time when the mass media is redefining itself at a level unmatched in human history. In fact, basic definitions of various long established mass media are rapidly evolving to include digital formats that would have seemed the stuff of science fiction a few years ago. Because of the rapid changes in mass media over the past several decades, this research will discuss the key subtopics related to mass media in an effort to better understand it overall. Mass Media Functions of Today’s Smart Phones and the I-Phone The evolution of mass media is quite literally a path that blazes through the history of the advancement of the human race. From the days when the ability to share the printed word on a large scale via the printing press to the telegraph, telephone, television and today the Internet and of course the smart phone, what has been seen is a way for the people of the world to communicate and for information such as news, advertising and the like to be spread. The mass media functions of today’s smart phones represent a tremendous advancement in mass media because the modern smart phone combines communication functions with the ability for the user of the smart phone to obtain information, be entertained, conduct business and to be marketed to by smart advertisers who are now harnessing smart phone technology to advertise products and services to a society that seems to be addicted to the use of the smart phone (Godwin-Jones). Overall, the I-Phone represents an innovation over its predecessors because of the user-friendly interface which gives the user of the phone the ability to load his or her own content into the phone, such as MP3 and video as well as the ability to access other available broadcast and downloadable material (Cortada). What this represents is an opportunity for the user to make the smart phone an extension of their own tastes in entertainment, and for the marketing of specific content, based on user interests. Today’s Early Adopters and Smart Phones Early adopters are in fact making the very most of the smart phone technology that is readily available today. Taking the utility of the smart phone far beyond the amazing ability to communicate with others in the blink of an eye, the smart phone is used today for commerce, the protection of the common order and safety, and to literally launch an entirely new segment of the modern economy. In commerce, the ability to use a phone to transmit massive amounts of data in an instant has made it possible for the trading of commodities, stocks and other negotiable instruments by millions of additional people, rapidly expanding the trading markets for these particular items (Cortada) and making it possible for literally billions of additional dollars to be injected into the financial markets in a very quick period of time. Public safety organizations and personnel utilize smart phone technology to coordinate efforts in times of emergency, to share the information that is needed across various agencies to achieve the goals of protecting the public, and to prevent crime as well as to apprehend dangerous criminal offenders in record time (Weir). The ability to use smart phones to market to individuals and also to conduct sales and business has also launched the age of the work from home entrepreneur who can run an entire operation from their pocket or purse (Wang). Also, this technology is being used for education, especially in the language learning fields, where the versatile communication elements of smart phones are well suited to language learning itself (Chinnery). All of these many uses for smart phones surely will lead to changes in the way we use mass media, because as mass media becomes more portable, the need for the traditionally stationary means of mass media such as televisions, radios and even printed media like books and newspapers evolve into content that is accessed by the pocket-sized smart phone. Since there are, and will continue to be more and more users of smart phones, it is fair to assume that media sources will focus on the latest means of spreading mass media, rather than wasting resources on outlets that face dwindling exposure. Limits on Today’s Smart Phone Technology For all of the great things that today’s smart phone technology makes possible, it must be noted that the technology has its limits. While innovations are constantly being made to thwart the treat of computer viruses, the widespread use of smart phones has led to what can be called epidemic proportions of viruses which have the ability to wipe out huge amounts of vital data just as fast as it could send it. This represents huge security risks to businesses because of the loss or theft of key business information, losses in productivity, and huge monetary costs to clean up and/or repair viruses that are spreading at incredibly fast paces. Of course, much of these problems are being intentionally inflicted by those who spread viruses merely for the malicious fun of doing so as well as those who illegally extract information from its rightful owners for purposes of identity theft and other fraud (Panettieri). The easy convenience of communication and the sharing of information are also posing an ethical problem in international academia. In generations past, the passing of notes from one student to another in the classroom was something that teachers forbade, but often did so with a chuckle because of the rather innocent nature of the offense. However, the modern smart phone has led to students spreading offensive material, personal information stolen from other students and such, which has made it possible for lives to be destroyed and reputations tarnished like never before. Clever students have also harnessed smart phone technology and mass media sources to cheat on examinations, leading to a massive erosion of academic integrity in the modern classroom (Godwin-Jones). On a more abstract level, the use of smart phones for the purposes of mass media has in many instances eaten away at the human experience of actually communicating with people in a face to face setting. As a result, society as a whole has become more fragmented, isolated and desensitized to the feelings, needs and problems of others. When life and death are reduced to electronic impulses on a tiny handheld screen, it is all too easy for the individual to simply switch off the device and pretend that what they had seen was not real. Meanwhile, the pain and suffering is in fact quite real, and if no one is attuned to this fact, the human race as a whole becomes somewhat artificial because they are not expected to be able to directly interact with people, but only communicate with them via text messages or voicemail for the most part. As a result, the art of communication which has advanced humanity up to this point is put aside and people revert back to a more primitive way of life when communication was unpopular and people were not as well informed as they should be. This will cause humanity to suffer, and should not be allowed to occur. Therefore, let it be noted that smart phones should be used as an aid to, and not a substitute for, human contact. Mass Media Opportunities for Smart Phones Smart phones, for all of their possible pitfalls, do in fact offer some wonderful mass media opportunities that are worth discussing. Consider, for example, a potential new product that needs to be test marketed. Rather than spending millions of dollars for conventional advertising, the gathering of test market groups in physical locations and the associated costs of travel, transportation and more, mass media via smart phone technology can instantly broadcast advertising messages, transmit marketing data, and keep in touch with potential customers all without the need for huge amounts of expensive equipment and the like. Also, intellectual products like music, literature and such can be instantly distributed, making it easy and fun to be entertained and culturally stimulated at the same time. Overall, what should be understood is that the mass media opportunities for smart phones are endless, and only time will tell how they ultimately manifest themselves. Conclusion Through this research, it has become clear that not only has mass media progressed to the point where it is available literally in one’s pocket or purse, but also to the point where exposure to mass media takes place for the average person on a constant basis. Perhaps most fascinating of all is the definite possibility that all of the innovations seen thus far are only the beginning of the journey, opening up limitless potential in the future. Therefore, in closing, while this research has concluded, for mass media, the journey is only beginning. Works Cited Chinnery, George M. â€Å"Going to the MALL: Mobile Assisted Language Learning. † Language, Learning & Technology 10. 1 (2006): 9+. Cortada, James W. The Digital Hand : How Computers Changed the Work of American Manufacturing, Transportation, and Retail Industries /. New York: Oxford University Press, 2004. Godwin-Jones, Robert. â€Å"Emerging Technologies E-Texts, Mobile Browsing and Rich Internet Applications. † Language, Learning & Technology 11. 3 (2007): 8+. Panettieri, Joseph C. â€Å"Don’t Be Out’smart’ed: The New Breed of Smart Mobile Phones Will Soon Pose the Biggest Danger to Your Data Security. Software Companies Are Gearing Up to Nullify the Threat. † T H E Journal (Technological Horizons In Education) 33. 7 (2006): 18+. Wang, Yuping. â€Å"Supporting Synchronous Distance Language Learning with Desktop Videoconferencing. † Language, Learning & Technology 8. 3 (2004): 90+. Weir, Tom. â€Å"Innovators or News Hounds?. † Newspaper Research Journal 20. 4 (1999): 62.

About Skateboarding Essay

Do you like danger? Do you like thrilling and exciting things that get your blood pumping? If you do, then skateboarding may be your thing. Skateboarding gives you an exciting and thrilling sensation, while at the same time giving you a true feeling of accomplishment. Although skateboarding is dangerous and exhilarating, through skateboarding can come new friends, seeing new places, and can just be a lot of fun. My life is filled with music, sports, and very many activities and hobbies, but to me skateboarding has taken me the farthest as a person, and has been the most exciting and fun. Something that skateboarding lets you do unlike other sports or hobbies, is traveling and exploring. For vacations, my friends and I will travel to various cities or sometimes states, with only one purpose. To find the famous spots that skateboarders from all over come to skate. For example, recently, my friends and I, (Ryan H. and Paul R.) traveled to Philadelphia. We had read about a couple of famous skate spots on the Internet and we decided they would be fun to look for and skate in the city. My mom drove us up for the day and we had a lot of fun. Another fun, out of town trip that my friends and I voyaged to, was a trip to New York City. In the skateboarding world there is a very famous place called Brooklyn Banks. Brooklyn Banks is ironically located directly under the Manhattan Bridge, and it is a spot that brings skateboarders from everywhere to skate. What makes this spot so amazing is that it is one of the very few fun and at the same time legal spots in New York to skateboard at. What Brooklyn Banks is exactly, is a tunnel like area made out of bricks. The sides of this tunnel are banks that are curved at the bottom, giving them the feel of a quarter pipe ramp when riding upon it. Also, along the floor, skateboarders have put up grind rails and boxes to skate on, making it like a skate park; and if you’re lucky you may actually see a pro skateboarder there skating it for fun. Who would have known that you don’t have to captain a ship to be an explorer? You can do the same on a skateboard. It gets a little boring skating the same spots every single day, so sometimes we go on adventures exploring through Annandale, Falls Church, and Alexandria just searching for fun spots to discover. One of our most favorite places to go to is Washington D.C. We skateboard in D.C almost every weekend, and we oftentimes explore spots there. In fact, we’ve gone to D.C so much, we now know our way around the subway system and city pretty well. Exploring new spots is fun because when you find a new spot and skate it, more people will come to it, and you’ll feel like you sort of claimed that spot and founded it just like the explorers of the past. Another fun thing about Washington D.C is that you meet a lot of cool people there who you see a lot and skate with a bunch. When you’re in D.C there are some spots that you know for a fact a bunch of kids will be skating, and if you ever get bored you can just meet some new friends and skate there. Some people enjoy calm activities, board games, and picnics, but to me there’s nothing better than the feeling of throwing yourself down some stairs or rolling up to a huge drop and getting that thrilling sensation like you do when you skateboard. One of the best things about skateboarding is that you can always progress with it and get better at it. There’s nothing better than learning a new trick or landing something harder than anything else you’ve ever done. I remember the first day I learned how to kickflip. The kickflip is the trick that finally brings you from that beginner level to the stage of improvement. It was one of the best feelings I’ve felt in my entire life. It was the same feeling I got when I ollied my first stair set. (An ollie is like jumping while on a skateboard) Another thrilling factor that skateboarding brings is that some of the best spots to skate are in sometimes bad parts of town or neighborhoods. Knowing that you’re in a dangerous neighborhood adds to the thrill and feeling of accomplishment after leaving. One of the biggest, yet thrilling aspects of skateboarding is knowing how, at any given moment, you could fall very hard and get hurt. This makes it all the more exciting when you land that one trick you’ve been going for. Earlier this year, I was skateboarding and I severely sprained my ankle. After I recovered, I made it a goal that I go back and land that same trick that I got hurt on before, so I could feel that excitement and conquer my fear from that certain spot. Thanks to skateboarding I have met many friends that I see almost every weekend and skateboard with all the time. Now-a-days, most kids just sit at home bored playing video games and not having anything to do on the weekends. This leads to a lot of kids doing drugs and getting into bad habits. A lot of people associate skateboarders with druggies and bad kids, when actually, in a way, skateboarding is like an anti-drug, which keeps us away from those bad things and always gives us something to do. What’s also good about skating is that even when were not skating and we’re just talking, we always have something to talk about or relate to. One of the best weeks I’ve ever lived was at a summer camp called Woodward. Woodward consisted of 18 different whole skate parks, BMX courses, gyms, and is the number one extreme sports camp around. At Woodward, every week of camp, new pro athletes come to do demos and skate the parks with the campers. The entire experience at that camp was amazing and I can’t wait to go back next summer. Skateboarding has opened up the door for some many amazing opportunities for me, and with out skateboarding who knows where I would be.