Six Stroke Ic Engine Essay Example for Free

Six Stroke Ic Engine Essay 1. INTRODUCTION A diesel engine is an internal combustion engine that uses the heat of compression to initiate ignition to burn the fuel, which is injected into the combustion chamber during the final stage of compression. Diesel engines have wide range of utilization for automobiles, locomotives marines and co-generation systems. However, large problem is still related to undesirable emission. The six-stroke engine is a type of internal combustion engine based on the four-stroke engine but with additional complexity to make it more efficient and reduce emissions. Two different types of six-stroke engine have been developed: In the first approach, the engine captures the heat lost from the four-stroke Otto cycle or Diesel cycle and uses it to power an additional power and exhaust stroke of the piston in the same cylinder. Designs use either steam or air as the working fluid for the additional power stroke. The pistons in this type of six-stroke engine go up and down three times for each injection of fuel. There are two power strokes: one with fuel, the other with steam or air. The currently notable designs in this class are the Crower Six-stroke engine invented by Bruce Crower of the U.S. ; the Bajulaz engine by the Bajulaz S.A. company of Switzerland; and the Velozeta Six-stroke engine built by the College of Engineering, at Trivandrum in India. The second approach to the six-stroke engine uses a second opposed piston in each cylinder that moves at half the cyclical rate of the main piston, thus giving six piston movements per cycle. Functionally, the second piston replaces the valve mechanism of a conventional engine but also increases the compression ratio. The currently notable designs in this class include two designs developed independently: the Beare Head engine, invented by Australian Malcolm Beare, and the German Charge pump, invented by Helmut Kottmann. To improve exhaust emissions from diesel engines, a new concept of Six Stroke Engine has been proposed. This engine has a second compression and combustion processes before exhaust process. [pic] Fig 1 Diesel engine sectional view Fig 2 Ideal Otto cycle [pic] Fig 3 Pressure- Volume diagrams for dual cycle As the fuel in one cycle was divided into two combustion processes and the EGR (Exhaust Gas Recirculation) effect appeared in the second combustion process, the decreased maximum cylinder temperature reduced Nitrous Oxide (NO) concentration in the exhaust gas. It was further confirmed that soot formed in the first combustion process was oxidized in the second combustion process .Therefore, a six stroke diesel engine has significant possibilities to improve combustion process because of its more controllable factors relative to a conventional four-stroke engine. Since the cylinder temperature before the second combustion process is high because of an increased temperature in the first combustion process, ignition delay in the second combustion process should be shortened. In addition, typically less desirable low cetane number fuels might also be suitable for use in the second combustion process, because the long ignition delays of these fuels might be improved by increased cylinder temperatures from the first combustion process. Methanol was chosen as the fuel of the second combustion. The cetane number of methanol is low and it shows low ignitability. However, since methanol will form an oxidizing radical (OH) during combustion, it has the potential to reduce the soot produced in the first combustion process. [pic] Fig 4 Comparison of 4 stroke and 6 stroke cycle 2. BAJULAZ SIX STROKE ENGINE The majority of the actual internal combustion engines, operating on different cycles have one common feature, combustion occurring in the cylinder after each compression, resulting in gas expansion that acts directly on the piston (work) and limited to 180 degrees of crankshaft angle. According to its mechanical design, the six-stroke engine with external and internal combustion and double flow is similar to the actual internal reciprocating combustion engine. However, it differentiates itself entirely, due to its thermodynamic cycle and a modified cylinder head with two supplementary chambers: Combustion, does not occur within the cylinder within the cylinder but in the supplementary combustion chamber, does not act immediately on the piston, and it’s duration is independent from the 180 degrees of crankshaft rotation that occurs during the expansion of the combustion gases (work). The combustion chamber is totally enclosed within the air-heating chamber. By heat exchange through the glowing combustion chamber walls, air pressure in the heating chamber increases and generate power for an a supplementary work stroke. Several advantages result from this, one very important being the increase in thermal efficiency. IN the contemporary internal combustion engine, the necessary cooling of the combustion chamber walls generates important calorific losses. 2.1 Analysis: Six-stroke engine is mainly due to the radical hybridization of two- and four-stroke technology. The six-stroke engine is supplemented with two chambers, which allow parallel function and results a full eight-event cycle: two four-event-each cycles, an external combustion cycle and an internal combustion cycle. In the internal combustion there is direct contact between air and the working fluid, whereas there is no direct contact between air and the working fluid in the external combustion process. Those events that affect the motion of the crankshaft are called dynamic events and those, which do not effect are called static events. [pic] Fig 5 Prototype of Six stroke engine internal view 1. Intake valve, 2.Heating chamber valve, 3.Combustion chamber valve,4. Exhaust valve, 5.Cylinder, 6.Combustion chamber, 7. Air heating chamber, 8.Wall of combustion chamber, 9.Fuel injector and 10.Heater plug. 2.1.1 Analysis of events [pic] Fig 6 Event 1: Pure air intake in the cylinder (dynamic event) 1. Intake valve. 2. Heating chamber valve 3. Combustion chamber valve. 4. Exhaust valve 5. Cylinder 6. Combustion chamber. 7. Air heating chamber. 8. Wall of combustion chamber. 9. Fuel injector. 10. Heater plug. [pic] Fig 7 Event 2: Pure air compression in the heating chamber. Event 3: Keeping pure air pressure in closed chamber where a maximum heat exchange occurs with the combustion chambers walls, without direct action on the crankshaft (static event). [pic] Fig 8 Event 4: Expansion of the Super heat air in the cylinder work (dynamic Event). [pic] Fig 9 Event 5: Re-compressions of pure heated air in the combustion chamber (dynamic event). Events 6: fuel injection and combustion in closed combustion chamber, without direct action on the crankshaft (static event). [pic] Fig 10 Events 7: Combustion gases expanding in the cylinder, work (dynamic event). [pic] Fig 11 Events 8: Combustion gases exhaust (dynamic event). [pic] Fig 12 Six-stroke engine cycle diagram: 2.1.2 External combustion cycle: (divided in 4 events): No direct contact between the air and the heating source. e1. (Event 1) Pure air intake in the cylinder (dynamic event). e2. (Event 2) Compression of pure air in the heating chamber (dynamic event). e3. (Event 3) Keeping pure air pressure in closed chamber where a maximum heat exchange occurs with the combustion chambers walls, without direct action on the crankshaft (static event). e4. (Event 4) Expansion of the super heated air in the cylinder, work (dynamic event). 2.1.3 Internal combustion cycle: (divided in 4 events) Direct contact between the air and the heating source. I1. (Event 5) Re-compression of pure heated air in the combustion chamber (dynamic event) I2. (Event 6) Fuel injection and combustion in closed combustion chamber, without direct action on the crankshaft (static event). I3. (Event 7) Combustion gases expanding in the cylinder, work (dynamic event). I4. (Event 8) Combustion gases exhaust (dynamic event). 2.2 Constructional details: The sketches shows the cylinder head equipped with both chambers and four valves of which two are conventional (intake and exhaust). The two others are made of heavy-duty heat-resisting material. During the combustion and the air heating processes, the valves could open under the pressure within the chambers. To avoid this, a piston is installed on both valve shafts which compensate this pressure. Being a six-stroke cycle, the camshaft speed in one third of the crankshaft speed. The combustion chambers walls are glowing when the engine is running. Their small thickness allows heat exchange with the air-heating chamber, which is surrounding the combustion chamber. The air-heating chamber is isolated from the cylinder head to reduce thermal loss. Through heat transfer from the combustion chamber to the heating chamber, the work is distributed over two strokes, which results in less pressure on the piston and greater smoothness of operation. In addition, since the combustion chamber is isolated from the cylinder by its valves, the moving parts, especially the piston, are not subject to any excessive stress from the very high temperatures and pressures. They are also protected from explosive combustion or auto-ignition, which are observed on ignition of the air-fuel mixture in conventional gas or diesel engines. The combustion and air-heating chambers have different compression ratio. The compression ratio is high for the heating chamber, which operates on an external cycle and is supplied solely with pure air. On the other hand, the compression ratio is low for the combustion chamber because of effectively increased volume, which operates on internal combustion cycle. The combustion of all injected fuel is insured, first, by the supply of preheated pure air in the combustion chamber, then, by the glowing walls of the chamber, which acts as multiple spark plugs. In order to facilitate cold  starts, the combustion chamber is fitted with a heater plug (glow plug). In contrast to a diesel engine, which requires a heavy construction, this multi-fuel engine, which can also use diesel fuel, may be built in a much lighter fashion than that of a gas engine, especially in the case of all moving parts. Injection and combustion take place in the closed combustion chamber, therefore at a constant volume, over 360 degrees of crankshaft angle. This feature gives plenty of time for the fuel to burn ideally, and releases every potential calorie (first contribution to pollution reduction). The injection may be split up, with dual fuel using the SNDF system (Single Nozzle, Dual Fuel). The glowing walls of the combustion chamber will calcite the residues, which are deposited there during fuel combustion (second contribution to pollution reduction). As well as regulating the intake and exhaust strokes, the valves of the heating and the combustion chambers allow significantly additional adjustments for improving efficiency and reducing noise. 2.3 Factors Contributing To the Increased Thermal Efficiency, Reduced Fuel Consumption, and Pollutant Emission 1. The heat that is evacuated during the cooling of a conventional engine’s cylinder head is recovered in six-stroke engine by air-heating chamber surrounding the combustion chamber. 2. After intake, air is compressed in the heating chamber and heated through 720 degrees of crankshaft angle, 360 degrees of which in closed chamber (external combustion). 3. The transfer of heat from thin walls of the combustion chamber to the air heating chambers lowers the temperature, pressure of gases on expansion and exhaust (internal combustion). 4. Better combustion and expansion of gases that take place over 540 degrees of crankshaft rotation, 360 ° of which is in closed combustion chamber, and 180 ° for expansion. 5. Elimination of the exhaust gases crossing with fresh air on intake. In the six stroke-engines, intake takes place on the first stroke and exhaust on the fourth stroke. 6. Large reduction in cooling power. The water pump and fan outputs are reduced. Possibility to suppress the water cooler. 7. Less inertia due  to the lightness of the moving parts. 8. Better filling of the cylinders on the intake due to the lower temperature of the cylinder walls and the piston head. 9. The glowing combustion chamber allows the finest burning of any fuel and calcinate the residues. 10. Distribution of the work: two expansions (power strokes) over six strokes, or a third more than the in a four-stroke engine. Since the six-stroke engine has a third less intake and exhaust than a four stroke engine, the depression on the piston during intake and the back pressure during exhaust are reduced by a third. The gain in efficiency balances out the losses due to the passage of air through the combustion chamber and heating chamber valves, during compression of fresh and superheated air. Recovered in the six-stroke engine By the air-heating chamber surrounding the combustion. Friction losses, theoretically high er in the six-stroke engine, are balanced by a better distribution of pressure on the moving parts due to the work being spread over two strokes and the elimination of the direct combustion. 3. DUAL FUEL SIX STROKE ENGINE 3.1 Working The cycle of this engine consists of six strokes: 1. Intake stroke 2. First compression stroke 3. First combustion stroke 4. Second compression stroke 5. Second combustion stroke 6. Exhaust stroke [pic] Fig 13 Concept of a Six-stroke diesel engine 3.1.1 Intake or Suction stroke To start with the piston is at or very near to the T.D.C., the inlet valve is open and the exhaust valve is closed. A rotation is given to the crank by the energy from a flywheel or by a starter motor when the engine is  just being started. As the piston moves from top to bottom dead centre the rarefaction is formed inside the cylinder i.e. the pressure in the cylinder is reduced to a value below atmospheric pressure. The pressure difference causes the fresh air to rush in and fill the space vacated by the piston. The admission of air continues until the inlet valve closes at B.D.C. 3.1.2 First Compression stroke Both the valves are closed and the piston moves from bottom to top dead centre. The air is compressed up to compression ratio that depends upon type of engine. For diesel engines the compression ratio is 12-18 and pressure and temperature towards the end of compression are 35-40 kgf/cm2 and 600-700 0C 3.1.3 First combustion stroke This stroke includes combustion of first fuel (most probably diesel) and expansion of product of combustion. The combustion of the charge commences when the piston approaches T.D.C. Here the fuel in the form of fine spray is injected in the combustion space. The atomization of the fuel is accomplished by air supplied. The air entering the cylinder with fuel is so regulated that the pressure theoretically remains constant during burning process. In airless injection process, the fuel in finely atomized form is injected in combustion chamber. When fuel vapors raises to self ignition temperature, the combustion of accumulated oil commences and there is sudden rise in pressure at approximately constant volume. The combustion of fresh fuel injected into the cylinder continues and this ignition is due to high temperature developed in engine cylinder. However this latter combustion occurs at approximately constant pressure. Due to expansion of gases piston moves downwards. The reciprocating motion of piston is converted into rotary motion of crankshaft by connecting  rod and crank. During expansion the pressure drop is due to increase in volume of gases and absorption of heat by cylinder walls. 3.1.4 Second compression stroke Both the valves are closed and the piston moves from bottom to top dead centre. The combustion products from the first compression stroke are recompressed and utilized in the second combustion process before the exhaust stroke. In typical diesel engine combustion the combustion products still contains some oxygen. 3.1.5 Second combustion stroke This stroke includes combustion of second fuel having low cetane (Cetane number of fuel is defined as percent volume of cetane (C16H34) in a mixture of cetane and alpha-methyl-naphthalene that produces the same delay period or ignition lag as the fuel being tested under same operating conditions on same engine). The combustion of the charge commences when the piston approaches to TDC. The second fuel injected into recompressed burnt gas can be burnt in the second combustion process. In other words combustion process of the second fuel takes place in an internal full EGR (Exhaust Gas Recirculation) of the first combustion. This second combustion process was the special feature of the proposed Six Stroke DI Diesel Engine. 3.1.6 Exhaust stroke The exhaust valve begins to open when the power stroke is about to complete. A pressure of 4-5 kgf/cm2 at this instant forces about 60% of burnt gases into the exhaust manifold at high speed. Much of the noise associated with automobile engine is due to high exhaust velocity. The remainder of burnt gases is cleared of the swept volume when the piston moves from TDC to BDC. During this stroke pressure inside the cylinder is slightly above the atmospheric value. Some of the burnt gases are however  left in the clearance space. The exhaust valve closes shortly after TDC. The inlet valve opens slightly before the end of exhaust stroke and cylinder is ready to receive the fresh air for new cycle. Since from the beginning of the intake stroke the piston has made six strokes through the cylinder (Three up And Three down). In the same period crank shaft has made three revolutions. Thus for six stroke cycle engine there are two power strokes for every three revolutions of crank shaft. 3.2 Performance analysis 3.2.1 Modification over four stroke diesel engine This six-stroke diesel engine was made from a conventional four-stroke diesel engine with some modification. A sub-shaft was added to the engine, in order to drive a camshaft and injection pumps. The rotation speed of the sub-shaft was reduced to 1/3 of the rotation of an output shaft. To obtain similar valve timings between a four-stroke and a six-stroke diesel engine, the cam profile of the six-stroke diesel engine was modified. In order to separate the fuels, to control each of the injection timings and to control each injection flow rate in the first and the second combustion processes, the six-stroke diesel engine was equipped with two injection pumps and two injection nozzles. The injection pumps were of the same type as is used in the four-stroke diesel engine. The nozzle is located near the center of a piston cavity, and has four injection holes. For the six-stroke diesel engine, one extra nozzle was added on the cylinder head. This extra nozzle was of the same design as that of the four-stroke engine. [pic] Fig 14 Volume –Angle diagram for six stroke engine Diesel fuel for the first combustion process was injected through this extra nozzle, and methanol for the second combustion process was injected through the center nozzle. Here, we denoted the injection timing of the four  stroke diesel engine as Xi. The injection timings of the first and second combustion strokes for the six-stroke diesel engine are shown as Xi I and Xi II, respectively. Crank angle X was measured from the intake BDC. In the six-stroke engine, crank angle of the first combustion TDC is 180 degrees. The second combustion TDC is 540 degrees. Specifications of the test engines are shown in Table 1. The conventional four-stroke diesel engine that was chosen as the basis for these experiments was a single cylinder, air cooled engine with 82 mm bore and 78 mm stroke. The six-stroke engine has the same engine specifications except for the valve timings. However, the volumetric efficiency of the six-stroke engine showed no significant difference from that of the four-stroke engine. Characteristics of the six-stroke diesel engine were compared with the conventional four-stroke diesel engine. In this paper, the engine speed (Ne) was fixed at 2,000 rpm. Cylinder and line pressure indicators were equipped on the cylinder head. NO concentration was measured by a chemiluminescence’s NO meter, and soot emission was measured by a Bosch smoke meter. The physical and combustion properties of diesel fuel and methanol are shown in Table. 2. Since combustion heats of diesel fuel and methanol are different, injection flow rates of the first and the second combustion processes are defined by the amount of combustion heat. Here, the supplied combustion heat for the first combustion process is denoted by QI. The second combustion stroke is denoted by QII. The ratio of QII to Qt (Qt = QI+QII) supplied combustion heat per cycle) is defined as the heat allocation ratio ÃŽ ±H: ÃŽ ±H = QII = QII QI +QII Qt Table 1. Specifications of the test engine: Four stoke Six stroke Diesel Engine Diesel Engine Engine type DI, Single cylinder, Air cooled, OHV Bore x Stroke [mm] 82 x 78 Displacement [cc] 412 Top Clearance [mm] 0.9 Cavity Volume [cc] 16 Compression ratio 21 Intake Valve Open100 BTDC70 BTDC Intake valve Close1400 BTDC1450 BTDC Exhaust Valve Open1350 ATDC1400 ATDC Exhaust Valve Close120 ATDC30 ATDC Valve Overlap 220 100 Rated power 5.9 kW /3000rpm Base Engine - Table 2. Physical and combustion properties of diesel fuel and methanol: | |Diesel Fuel |Methanol | |Combustion heat [MJ/kg] |42.7 |19.9 | |Cetane number |40-55 |3.0 | |Density [kg/m2] |840 |793 | |Theoretical air-fuel ratio |14.6 |6.5 | 3.3 Performance of six stroke diesel engine 3.3.1 Comparison with four stroke diesel engine A four-stroke engine has one intake stroke for every two engine rotations. For the six-stroke engine, however, the intake stroke took place once for every three engine rotations. In order to keep the combustion heat per unit time constant, the combustion heat supplied to one six-stroke cycle should be 3 or 2 times larger than that of the four-stroke engine. There are many ways to compare performance between the four-stroke and six-stroke engines. For this paper, the authors have chosen to compare  thermal efficiency or SFC at same output power. If the thermal efficiency was the same in both engines, the same output power would be produced by the fuels of equivalent heats of combustion. Therefore, in order to make valid comparison, fuels supplied per unit time were controlled at the same value for both engines and engine speeds were kept constant. In this section, fuel supplied for the engines was only a diesel fuel. Performance of the six-stroke engine was compared with that of the four-stroke engine under various injection timings. Detailed conditions for comparison of the four-stroke and six-stroke engines are listed in Table. 3. The heat allocation ratio of the six-stroke engine was set at ÃŽ ±H = 0.5. Injection flow rate of fuel was Qt4 = 0.50 KJ/cycle for the four-stroke engine and Qt6 = 0.68 KJ/cycle for the six stroke engine. For six stroke engine, it meant that the amount of 0.34KJ was supplied at each combustion process. At the viewpoint of combustion heat, 0.75 KJ/cycle of heat should be supplied for the six stroke engine to make the equivalence heat condition. However diesel fuel of 0.68 KJ/cycle was supplied here because of difficulties associated with methanol injection. Injection timing of the four-stroke engine was changed from 160 degrees (200BTDC) to 180 degrees (TDC). For six -stroke engine, the injection timing of the first combustion process was fixed to 165 degrees (15 °BTDC) or 174 degrees (6 °BTDC), and the second injection timing was changed from 520 degrees (2000 BTDC) to 540 degrees (TDC). [pic] Fig 15 Valve timing diagram four stroke engine Table 3. Detailed conditions of comparison between the four stroke and six stroke diesel engines and performance of engine | |Four Stroke |Six Stroke | |Engine Parameters |Diesel Engine |Diesel Engine | |Engine Speed Ne [rpm] |2007 |2016 | |Supplied combustion heat per cycle | | | |Qt [KJ/cycle] |0.50 |0.68 | |Supplied combustion heat per unit time Ht [KJ/s] | | | | |8.36 |7.62 | |Intake air flow per cycle | | | |Ma [mg/cycle] |358.7 |371.4 | |Injection quantity per cycle | | | |Mf [mg/cycle] |11.8 |16 | | | | | |Excess air ratio ÃŽ » |2.40 |1.83 | |Intake air flow per unit time | | | |Ma [g/cycle] |6.00 |4.16 | |Injection quantity per unit time | | | |Mf [g/sec] |0.197 |0.179 | |Brake torque Tb [N-m] |15.52 |15.28 | |Brake power Lb [KW] |3.26 |3.24 | |BSFC. b [ g / KW-h] |217.9 |520.3 | |IMEP Pi [Kgf / cm2] |5.94 |4.37 | |Indicated torque Ti [N-m] |19.10 |18.71 | |Indicated power Li [KW] |4.01 |3.75 | |ISFC bi [g / KW-h ] |177.2 |163.3 | Indicated torque of the six-stroke engine is almost same level with that of the four-stroke engine under various injection timings. NO concentration in exhaust gas of the six-stroke engine was lower than that of the four-stroke engine. NO emissions from both engines were reduced by the retard of injection timing. The effect of retard in the second injection timing of the six-stroke engine was similar to that of the retard in the four-stroke engine. For the six-stroke engine, from the comparison between Xi I = 165 degrees (15 °BTDC) and Xi I = 174 degrees (6 °BTDC), it seemed that the NO reduction effect appeared with the timing retard in the first combustion process. Soot emission in the exhaust gas of the four-stroke engine was low level and it was not affected by the timing retard of injection. However, the level of soot emission from the six-stroke engine was strongly affected by the timing of the second injection. When the injection timing was advanced from 528 degrees (12 ° BTDC), it was confirmed that the soot emission was lower than that of the four-stroke engine. From numerical analysis, it was considered that the soot formed in the first combustion process was oxidized in the second combustion process. On the contrary, when the injection timing was retarded from 528 degrees (12 ° BTDC), soot emission increased with the timing retard. Then, it was considered that the increased part of the soot was formed in the second combustion process because an available period for combustion was shortened with the retard of injection timing. Experimental conditions were Xi = Xi I = 170 degrees (100 BTDC) and XiII=530 degrees (100 BTDC). The heat allocation ratio of six stroke engine was ÃŽ ±H=0.5. The cylinder temperature and heat release rate were calculated from the cylinder pressure. The pattern of heat release rate in the first combustion stroke of the six-stroke engine was similar to that of the heat release rate of the four-stroke engine. It was the typical combustion pattern that contained a pre-mixed combustion and diffusion combustion. On the other hand, since an increase of cylinder temperature in the second combustion process was caused by the compression of the burned gas formed in the first combustion stroke, a pre-mixed combustion in the second combustion process was suppressed by a short ignition delay. The maximum cylinder temperature in the first combustion process was lower than that in the four-stroke engine. It was caused by smaller amount of fuel which was injected in the first combustion process. Considering these results, it was proved that NO concentration in the exhaust gas was reduced by the decrease of the maximum cylinder temperature in the first co mbustion process and EGR effect in the second combustion process. The performance of these two engines could be compared by Table. 3. Since BSFC of the six-stroke engine obtained by the brake power suffered, SFC is compared with ISFC for the Xi = 163 degree (170 BTDC), ISFC of the four-stroke engine was 177.2 g/KW-h. On the other hand, for the Xi I = 165 degrees (15 ° BTDC) and Xi II = 523 degrees (170 BTDC), I.S the six-stroke engine was 163.3 g/KW-h. i.e. ISFC of the six-stroke engine was slightly lower than that of the four-stroke engine. It was considered that this advantage in ISFC was caused by a small cut-off ratio of constant pressure combustion. Because, in the six-stroke engine proposed here, the fuel divided into two combustion processes resulted in a short combustion period of each combustion process. Furthermore, in the reduction of NO emission, the six-stroke engine was superior to the four-stroke engine. 3.3.2 Effect of heat allocation ratio Injection conditions were Xi I = 170 degrees (1000 BTDC) and Xi II = 530 degrees (100 BTDC). Both fuels in the first and second combustion processes were diesel fuel. Total fuel at the combustion heat basis was Qt = 0.68 KJ/cycle. It meant a high load in this engine because the total excess air ratio was 1.83 as previously shown in Table 3. The maximum value of the indicated torque appeared around ÃŽ ±H = 0.5 NO concentration in exhaust gas was reduced by an increase of heat allocation ratio. In other words, NO emission decreased with an increase of the fuel of the second combustion process. In the case of ÃŽ ±H = 0.5, there is a relatively long ignition delay in the first combustion process and pre-mixed combustion was the main combustion phenomena in it. NO of high concentration was formed in this pre-mixed combustion process. On the other hand, in the case of ÃŽ ±H = 1, diffusion combustion was the main combustion phenomena and NO emission was low. Soot emission in exhaust gas increased with an increase of heat allocation ratio. Since the injection flow rate in the second combustion process increased with an increase of the heat allocation ratio, the injection period increased with an increase of the heat allocation ratio. It caused the second combustion process to be long, and unburnt fuel that was the origin of soot remained after the second combustion process. The heat release rates on ÃŽ ±H = 0.15 and ÃŽ ±H = 0.85. For ÃŽ ±H =0.15, since injection flow rate in the first combustion process was high and injection period in it was long, the combustion period in the first combustion process became long as compared with case of ÃŽ ±H = 0.85. On the other hand, for ÃŽ ±H = 0.85, the combustion period in the second combustion process became long as compared with case of ÃŽ ±H=0.15. It was also observed that the long combustion periods in both the first and second combustion were caused by the long diffusion combustion. Further, diffusion combustion was the main combustion phenomena of the second combustion process. When the heat allocation ratio was 0.85, the ratio of heat release rates between the first and second combustion should be 15: 85, however the actual ratio obtained from the figure was 46: 54. This inconsistency was caused from the drift of the base lines of the heat release diagrams. For ÃŽ ±H = 0.15, the actual ratio of heat release rates was 73: 27 with the similar reason. The cylinder temperature for the ÃŽ ±H = 0.15 condition was higher than that of the ÃŽ ±H = 0.85 condition. This could be explained as follows. In the first combustion stroke, since the injection flow rate of ÃŽ ±H = 0.15 was higher than that of ÃŽ ±H = 0.85, the combustion temperature for the ÃŽ ±H = 0.15 condition was higher than that of ÃŽ ±H = 0.85. In the second compression stroke, since the high temperature burned gas was re-compressed, the temperature of ÃŽ ±H = 0.15 was also higher than that of ÃŽ ±H = 0.85. As a result, the temperature at the beginning of the second combustion stroke was high in ÃŽ ±H = 0.15 condition as compared with ÃŽ ±H = 0.85 condition. At the later stage of the second combustion, however, the opposite relationship between these two temperatures were observed, because the injection flow rate of the second combustion process was low in ÃŽ ±H = 0.15 condition. The maximum temperatures in the first and second combustion process decreased with an increase of the heat allocation ratio. Then, it could be concluded that the reduction of NO concentration with the heat allocation ratio, was caused by the decrease of the cylinder temperature. 3.4 Performance of the dual fuel six stroke diesel engine 3.4.1 Comparison with diesel fuel six stroke engine Operating conditions of comparison between the diesel fuel and the dual fuel six-stroke engines are shown in Table. 4. Experimental conditions were Xi I= 170 degrees (100 BTDC), Xi II = 530 degrees (10o BTDC) and ÃŽ ±H = 0.5. In dual fuel six-stroke engine, diesel fuel and methanol were supplied into first and second combustion process, independently. Combustion heats supplied per one cycle of the diesel fuel and dual fuel six-stroke engines were same. The combustion heat supplied per one cycle was selected as Qt = 0.43 KJ/cycle under the middle load condition. Performance of the dual fuel six-stroke engine was compared with the diesel fuel six-stroke engine under various injection timings in the second combustion process. Indicated torques of both engines was revealed constant around 15 N-m. As a result, it could be concluded that states of combustion of the diesel fuel and the dual fuel six-stroke engines had similar contributions on the engine performance. NO emissions from the dual fuel six-stroke engine were lower than those of the diesel fuel six-stroke engine. This effect appeared prominently at the advanced injection timing of the second combustion. Further, NO concentrations of both engines were reduced by the injection timing retard in the second combustion. [pic] Fig 16 Torque- Angle diagram for six stroke engine Soot emission in the exhaust gas of the diesel fuel six stroke engines increased with a retard of the injection timing in the second combustion. For the dual fuel six-stroke engine, the exhaust level of soot was very low under various injection timings of the second combustion process. Soot was formed clearly by the combustion of diesel fuel in the first combustion process and it was oxidized in the second combustion process. Considering these results, it was possible to estimate that soot was almost oxidized by methanol combustion in the second combustion process. This estimation is supported by a dual fuel diesel engine operated with diesel fuel methanol. The combustion heat supplied per one cycle was selected as Qt = 0.68 KJ/cycle under the high load condition. Indicated torques of both engines was also revealed constant around 20 N-m. NO concentration had the same tendency as the cases of the middle load. Soot emission level of the diesel fuel six-stroke engine was high in this high load condition. For the dual fuel six-stroke engine, however, soot was very low under various injection timings of the second combustion process. The performance of these engines was compared in Table. 4. For the second combustion process, since combustion heats of diesel fuel and methanol were different, injection quantities of both engines were different. BSFC and ISFC of the dual fuel six-stroke engine was sensibly higher than that of the diesel fuel engine. To compare the performance of these engines, injection quantity of both engines was defined by an amount of combustion heat, and SFC should be calculated from it. As a result, indicated specific heat consumption of the diesel fuel six-stroke engine was 5.59 MJ/KW-h, and that of the dual fuel six-stroke engine was 5.43 MJ/KW-h. For the high load conditions shown in Table. 5, the similar advantage of the dual fuel six-stroke engine was observed. Table 4. Detailed conditions of comparison between the diesel fuel and dual fuel diesel engines and performance of engines under ÃŽ ±H = 0.5 and middle load | |Diesel Fuel Six Stroke Diesel |Dual Fuel Six Stroke | | |Engine |Diesel Engine | |Engine Speed Ne [rpm] |2016 |2003 | |Supplied combustion heat per cycle | | | |Qt [KJ/cycle] |0.43 | | |Injection quantity per cycle |5.0 | | |(First Combustion Stroke) |(Diesel Fuel) | | |Mf1 [mg/cycle] | | | |Injection quantity per cycle |5.0 |10.7 | |(Second Combustion Stroke) |(Diesel Fuel) |(Methanol) | |Mf2 [mg/cycle] | | | |Excess air ratio ÃŽ » |2.98 |3.15 | |Brake torque Tb [N-m] |3.14 |3.14 | |Brake power Lb [KW] |0.66 |0.66 | |B.S.F.C. b [ g / KW-h] | 610.9 |952.9 | |I.M.E.P. Pi [Kgf / cm2] |3.43 |3.53 | |Indicated torque Ti [N-m] |16.70 |15.12 | |Indicated power Li [KW] |3.1 |2.77 | |I.S.F.C. bi [g / KW-h ] |130.1 |198.4 | |Indicated specific heat consumption | | | |bi’ [MJ /KW-h] |5.59 |5.43 | In order to confirm the advantage of dual fuel six-stroke engine, the performance of these engines was compared with four-stroke engine as shown in Table. 6. NO concentrations of the diesel fuel and the dual fuel six-stroke engines were improved with 85 90% as compared with that of the four-stroke engine. Soot emission of the diesel fuel six-stroke engine was much higher than that of the four-stroke engine. However, for the dual fuel six-stroke engine, soot level was very low. Furthermore, the indicated specific heat consumption of the diesel fuel and dual fuel six-stroke engine were lower than that of the four-stroke engine. Especially, for the dual fuel six-stroke engine, the indicated specific heat consumption was improved with 15% as compared with that of the four stroke engine. From these results, it could be confirmed that the dual fuel six-stroke engine was superior to the diesel fuel six-stroke engine, and also it was superior to the four-stroke engine. Table 6. Percentage improvements of exhaust emission and specific heat consumption | |Four Stroke Diesel | Six Stroke Diesel Engine|Dual Fuel Six Stroke Engine | | |Engine | | | |NO [ppm] | |113 |90.5 | |( % improvement) |768 |(85.3%) |(88.2%) | |Soot [%] | |28.8 |0 | |(%improvement) |6.8 |(- 323.5%) |(100%) | |Indicated specific heat consumption bi’ | | | | |[MJ/KW-h] |7.51 |6.61 |6.37 | |(% improvement) | |(12.0%) |(15.2%) | Table 5. Detailed conditions of comparison between the diesel fuel and dual fuel diesel engine and performance of engines under ÃŽ ±H =0.5 and high load | | Six Stroke Diesel Engine |Dual Fuel Six Stroke Engine | |Engine Speed Ne [rpm] |2016 |2006 | |Supplied combustion heat per cycle | | | |Qt [kJ/cycle] |0.68 | | |Injection quantity per cycle |8.0 | | |(First Combustion Stroke) |(Diesel Fuel) | | |Mf1 [mg/cycle] | | | |Injection quantity per cycle |8.0 |17.2 | |(Second Combustion Stroke) |(Diesel Fuel) |(Methanol) | |Mf2 [mg/cycle] | | | |Excess air ratio ÃŽ » |1.86 |1.93 | |Brake torque Tb [N-m] |6.18 |6.08 | |Brake power Lb [kW] |1.52 |1.5 | |B.S.F.C. b [ g / kW.h] | 504.0 |777.7 | |I.M.E.P. Pi [kgf / cm2] |4.56 |4.75 | |Indicated torque Ti [N-m] |21.68 |20.38 | |Indicated power Li [kW] |3.45 |2.98 | |I.S.F.C. bi [g / kW.h ] |155.5 |236.2 | |Indicated specific heat consumption | | | |bi’ [MJ /kW.h] |6.61 |6.37 | 3.4.2 Effect of injection timing Performance of the dual fuel six-stroke engine under various injection timings in the second combustion process was investigated on middle and high load. Experimental conditions were Xi I = 170 degrees (100 BTDC) and ÃŽ ±H = 0.5. Performance of the dual fuel six-stroke engine under both load conditions had the similar tendency with the timing retard. NO concentrations in the high load condition were higher than those of the middle load condition. However, soot emission levels of both load conditions were extremely low under various injection timings of the second combustion. 3.4.3 Effect of heat allocation ratio Performance of the dual fuel six-stroke engine under various heat allocation ratios was investigated on middle and high load. Injection conditions were Xi I = 170 degrees (100 BTDC) and Xi II = 530 degrees (100 BTDC). Since the combustion heat of methanol was low, experimental range of heat allocation ratio was limited by the smooth operation of the engine. Only the range from ÃŽ ±H = 0.25 to 0.75 (on Qt = 0.43 KJ/cycle), and from ÃŽ ±H = 0 to 0.5 (on Qt = 0.68 KJ/cycle) could be tested.. Indicated torque increased with an increase of the heat allocation ratio. NO concentration in exhaust gas was reduced with an increase of the heat allocation ratio. Soot was very low, irrespective of the methanol flow rate. Even if the load condition was high, it was concluded that soot was practically eliminated by a small amount of methanol in the second combustion process (8% of total fuel). 4. ADVANTAGES OF SIX STROKE OVER FOUR STROKE ENGINES The six stroke is thermodynamically more efficient because the change in volume of the power stroke is greater than the intake stroke, the compression stroke and the Six stroke engine is fundamentally superior to the four stroke because the head is no longer parasitic but is a net contributor to – and an integral part of – the power generation within exhaust stroke. The compression ration can be increased because of the absent of hot spots and the rate of change in volume during the critical combustion period is less than in a Four stroke. The absence of valves within the combustion chamber allows considerable design freedom. 4.1 Main advantages of the duel fuel six-stroke engine: 4.1.1 Reduction in fuel consumption by at least 40%: An operating efficiency of approximately 50%, hence the large reduction in specific consumption. the Operating efficiency of current petrol engine is of the order of 30%. The specific power of the six-stroke engine will not be less than that of a four-stroke petrol engine, the increase in thermal efficiency compensating for the issue due to the two additional strokes. 4.1.2 Two expansions (work) in six strokes: Since the work cycles occur on two strokes (3600 out of 10800 ) or 8% more than in a four-stroke engine (1800 out of 720 ), the torque is much more even. This lead to very smooth operation at low speed without any significant effects on consumption and the emission of pollutants, the combustion not being affected by the engine speed. These advantages are very important in improving the performance of car in town traffic. 4.1.2 Dramatic reduction in pollution: Chemical, noise and thermal pollution are reduced, on the one hand, in proportion to the reduction in specific consumption, and on the other, through the engine’s own characteristics which will help to considerably lower HC, CO and NOx emissions. Furthermore, it’s ability to run with fuels of vegetable origin and weakly pollutant gases under optimum conditions, gives it qualities which will allow it to match up to the strictest standards. 4.1.3 Multifuel: Multifuel par excellence, it can use the most varied fuels, of any origin (fossil or vegetable), from diesel to L.P.G. or animal grease. The difference in inflammability or antiknock rating does not present any problem in combustion. It’s light, standard petrol engine construction, and the low compression ration of the combustion chamber; do not exclude the use of diesel fuel. Methanol-petrol mixture is also recommended. 5. CONCLUSIONS The performance of the dual fuel six-stroke engine was investigated. In this dual fuel engine, diesel fuel was supplied into the first combustion process and methanol was supplied into the second combustion process where  the burned gas in the first combustion process was re-compressed. The results are summarized as follows. 1. Indicated specific fuel consumption (ISFC.) of the six-stroke engine proposed here is slightly lower than that of the four-stroke engine (about 9% improvement). NO and soot emissions from the six-stroke engine was improved as compared with four-stroke engine under advanced injection timings in the second combustion stroke. 2. For the dual fuel six-stroke engine, the timing retard and an increase of heat allocation ratio in the second combustion stroke resulted in a decrease of the maximum temperatures in the combustion processes. It caused the reduction of NO emission. 3. For the dual fuel six-stroke engine, soot was practically eliminated by a small amount of methanol in the second combustion process. 4. From the comparison of the performance between the dual fuel six-stroke and the four-stroke engine, it was concluded that indicated specific heat consumption of the dual fuel six-stroke engine was improved with 15% as compared with the four-stroke engine. NO concentration of the dual fuel six-stroke engine was improved with 90%. Furthermore, soot emission was very low in the dual fuel six-stroke engine. 5. As the fuel in one cycle was divided into two combustion processes and the EGR effect appeared in the second combustion process, the decreased maximum cylinder temperature reduced NO concentration in the exhaust gas It was further confirmed that soot formed in the first combustion process was oxidized in the second combustion process .Therefore, a six stroke DI diesel engine has significant possibilities to improve combustion process because of its more controllable factors relative to a conventional four-stroke engine. Considering these results, it was confirmed that the dual fuel six-stroke engine was superior to the four-stroke engine. 6. REFERENCES 1. Tsunaki Hayasaki, Yuichirou Okamoto, Kenji Amagai and Masataka Arai â€Å"A Six-stroke DI Diesel Engine under Dual Fuel Operation â€Å"SAE Paper No 1999-01-1500 2. S.Goto and K.Kontani, A Dual Fuel Injector for Diesel Engines, SAE paper, No. 851584, 1985 3. â€Å"Internal Combustion Engines â€Å"A book by Mathur Sharma. 4. â€Å"Internal Combustion Engines† Tata McGraw-hill publications, Author V Ganesan 7. NOMENCLATURE Ne : Engine speed X : Crank angle Xi : Injection timing of the four-stroke diesel engine ÃŽ ±H : Heat allocation ratio Q : Supplied combustion heat Qt : Supplied combustion heat per cycle P : Cylinder pressure V : Cylinder volume Vs : Stroke volume Pi : Indicated mean effective pressure (LM.E.P) Ti : Indicated torque Li : Indicated power Tb : Brake torque Lb : Brake power Ht : Supplied combustion heat per unit time Ma : Intake air flow per cycle Ma : Intake air flow per unit time Mf : Injection quantity per cycle Mi : Injection quantity per unit time ÃŽ » : Excess air ratio b : Brake specific fuel consumption (B.S.F.C.) bl : Indicated specific fuel consumption (I.S.F.C.) bi : Indicated specific heat consumption SUBSCRIPTS I: first combustion stroke II: second combustion stroke 4: four-stroke diesel engine 6: six-stroke diesel engine

Impact of Supply Chain Strategies on Performance

Impact of Supply Chain Strategies on Performance Introduction The concept of Supply Chain Management (SCM), introduced to address the issue of integration of organizational functions ranging from the ordering and receipt of raw materials through the manufacturing processes to the distribution and delivery of products to customers with a view to enable organizations to achieve higher quality in products and customer service and to lower inventory cost, has attracted considerable managerial attention in recent times mainly because of its huge potential competitive impact (Stevens, 1989). Experience, however, demonstrates that managers adopt a variety of disparate approaches to SCM implementation. In this context, design of an effective supply chain network has become a crucial issue for any company to survive in a fiercely competitive market. The SCM concerns with issues and characteristic features of several interrelated factors and activities of an organization, such as demand forecasting, procurement, manufacturing, distribution, inventory, tr ansportation, and customer service, and the resulting integrated approach is extended to customers and suppliers (Christopher, 1992). Considering the implications of all these aspects, a number of issues in SCM have assumed importance in the context of prevailing industrial scenario in India in order to make SCM more effective. Numerous papers have been published in the literature advocating the principles and the benefits of SCM [Beesley (1997), Lurquin (1996), Mason-Jones and Towill (1998), and Towill (1996)]. Many case studies have also been published evidencing the benefits of SCM [Arntzen, et al., (1995), Calza and Passaro (1997), and Lee and Billington (1995)]. There are several studies on SCM practices in different countries reported in the literature [Gilmour et al. (1995), Handfield and Withers (1993), Cilliers and Nagel (1994), McMullan (1996), Cox (1999)], and it is felt that an effort on design and development of SCM practices including issues, such as IT application, performance measures used, and barriers of SCM implementation is very much needed in India. On reviewing the existing SCM literature, several major weaknesses in the conceptualization and modeling of SCM are found. In particular, the SCM construct is perceived as an extension of integrated purchasing and supply management, or integrated logistics and transportation management. It appears that a coherent view on SCM concept has yet to develop in the existing literature, and it makes a prerequisite to conduct a survey on the important issues of SCM before a comprehensive methodology for supply chain performance measurement and evaluation system for the Indian Tyre manufacturing industries is prescribed. This paper reports the details of a questionnaire-based survey to study the status and scope of SCM practices in Indian Tyre manufacturing companies and also provides a brief overview of the similar surveys on SCM already undertaken in different industries. Objectives of the Survey The primary objective of the survey is to explore and understand, in quantitative terms wherever possible, the issues in SCM practices and concerns of the Tyre manufacturing industries in India. In specific terms, the objectives are related to the following aspects: †¢ Present status and scope of SCM practices; †¢ Role of Information Technology (IT) in SCM; †¢ Performance measures used in SCM, †¢ Benefits of employing SCM practices; and †¢ Specific issues hindering SCM practices. It is assumed that addressing the above-mentioned issues, as all of them are related to SCM strategies and practical constraints, would lead to understanding the status and scope of SCM practices in Indian Tyre manufacturing industries. Presently, the majority of the Indian companies have a weak alignment of supply chain strategy with business strategy. This is primarily so because the companies are rigidly structured along functional lines with department-specific performance measures. Survey Methodology A survey instrument, in the form of a questionnaire, is used in order to fulfill the objectives as mentioned. The questionnaire designed for the survey, will be conducted during December, 2010, for nearly 18 companies covering Tyre manufacturing industry in various regions of the country. Various lists of manufacturing companies, Internet websites of the companies, and personal contacts were the main sources for obtaining information about the companies and creating a database. The companies were selected randomly from the database. Although the survey will be conducted for a specific time period, the issues considered remain highly relevant for understanding the operating principles, norms, problems, and implementation aspects of SCM practices in the Indian Tyre manufacturing companies. The questionnaire is designed to know about the responding companies, their main objectives of employing SCM, positions of companies in the supply chain for their primary products, and views of the respondents on the principles of effective SCM practices. The questionnaire was divided into two sections: Section A and Section B. Section A was designed for the companies which have already implemented the SCM concepts like information sharing with suppliers and customers, or have decided to implement SCM concepts in near future, contains questions pertaining to several important issues related to SCM practices, such as a companys role in servicing customers needs, its role as a customer to its suppliers, the role of IT in SCM, the performance measures used in supply chain performance evaluation, and the activities or actions hindering SCM practices. Section B presents the items related to several types of barriers and government policies commonly found in implementing SCM practices in t he Indian Tyre manufacturing industries. A combination of checks, yes/no, `Likert scale, and multiple choice questions are framed against the issues as mentioned. The following specific tests will be employed on the data obtained: †¢ Two-Tailed Significance Test-this provides a level of significance for differences between two groups to a question requiring a response using a Likert scale. †¢ Bivariate Correlation (Pearson) Coefficient-this tests the relationships between responses to two different questions. The test provides a `p value indicating the strength of the relationship. A value of p=0 represents no relationship, and p= ±1 a strong relationship, and shows the significance level of the relationships. †¢ Reliability Analysis-In order to assess the homogeneity and inter-correlations of the factors used in an item, Cronbach alpha (a) [Cronbach (1951)], a measure of internal consistency often used in cases where participants respond to questions on a Likert scale The values of a lies in the range (0, 1). For the purpose of analysis, the survey responses are divided into three categories: Category 1: Questions that need ranking of alternatives (Likert-scale questions) The importance of the alternatives under each issue is established based on the values of statistics obtained. Category 2: Questions requiring degree of agreement (multiple choice questions) For the questions requiring degree of agreement, Specific issues such as main objectives of SCM, principles of effective SCM practices, integration of divisional areas in the supply chains, information communication tools with suppliers and customers, area of IT applications, and barriers of SCM implementation are included in this category. The percent responses of all the alternatives under each issue are computed and the rankings of the alternatives are done based on the percent responses resulting in identifying the important alternatives. Category 3: Yes/No type questions For this category, two yes/no type close-ended questions have been framed against different issues. The percent responses of `Yes/No is computed against each issue, which provide the general views of the respondents on a particular issue. Company Details Apollo Tyres Ltd Shanmugham Road Cochin, KL 682031 Phone : +91-0484-2381902/2381903/ 2380720/ 2372767/ 2363760 Birla Tyres Syed Amir Ali Avenue Kolkata, WB 700019     Email :  [emailprotected]  Phone : +91-33-22814516 Ceat Tyres Ceat Tyres. D 6/5, SMB ENGINEERS, TTC INUSTRIAL AREA MIDC TURBHE NAVI MUMBAI, MH 400705 Phone : +91-22-27622079 Elgitread (India) Ltd Elgitread (India) Ltd 2000 Trichy Road Coimbatore, TN 641005 Email :  [emailprotected]  Phone : +91-422- 4321000 Falcon Tyres Ltd Falcon Tyres Ltd K. R. S. Road Metagalli Mysore, KK 570 016 Email :  [emailprotected]  Phone : +91-821-2582453/ 2582055/ 2582041 Govind Rubber Limited Govind Rubber Limited G -15,Creative Industrial Estate,Sitaram Mill Compound,72-N. M. Joshi Marg Lower Parel Mumbai, MH 400 011 Email :  [emailprotected]  Phone : +91-22-2309 5641/1784 / 309 21124 / 309 21126 JK Tyres JK Tyres 3 Bahadurshah Zafar Marg New Delhi, DH 110002 Phone : +91-11-23311112/7 Malhotra Rubbers Limited Malhotra Rubbers Limited D-4, Sector 11 Noida, UP 201301 Email :  [emailprotected],[emailprotected],[emailprotected]  Phone : +91-120-2543028/2543029/2553724 Metro Tyres Metro Tyres Metro House, 134/4, 135/5 Zamrudpur Kailash Colony New Delhi, DH 110 048 Email :  [emailprotected],[emailprotected]  Phone : +91-11-6219097/98 Modi Rubber Modi Tyres Company Pvt. Limited. NH-58, Meerut Roorkee Road Modipuram 250110 MEERUT (Uttar Pradesh) MRF Tyres MRF LIMITED KOTTAYAM MANUFACTURING UNITS  P.B.No.2, Vadavathoor P.O., Kottayam, Kerala 686 010 Tel: 0481-2570461 (12 Lines) DID: 2575196/97/98, Royal Tyres Royal Tyres C-11 Mugappair Industrial Estate(East) Chennai, TN 600037 Email :  [emailprotected]        Ã‚     Ã‚     Ã‚     Ã‚     Ã‚     Ã‚     Ã‚     Ã‚     Ã‚     Ã‚     Ã‚     Ã‚     Ã‚     Ã‚     Ã‚     Ã‚     Ã‚     Ã‚     Phone : +91-44-26565643/42690079/42690089 TVS Srichakra Ltd TVS Building 7-B West Veli Street Madurai, 625001 India +91-45-2420461 (Phone) Questionnaire for The Impact of Supply Chain Strategies on the Performance of Indian Tyre Manufacturing Companies Part 1 Company Profile 1. Name of Company 2. Address 3. Country 4. Tel 5. Fax 6. Website 7. Contact person: 9. E-mail: 8. Position in company: No of employees: [______] Turnover 2009 : [_________________] Part 2 Theme 1 How do you manage your supply chain? Tick all that apply 1 Close partnership with suppliers 2 Close partnership with customers 3 JIT supply 4 e-procurement 5 EDI 6 Outsourcing 7 Subcontracting 8 3PL 9 Plan strategically 10 Supply Chain Benchmarking 11 Vertical integration 12 Few suppliers 13 Many suppliers 14 Holding safety stock 15 Use of external consultants 16 Other, please specify How successful do you think is your company in managing its supply chain in general? Not successful at all Not successful Somewhat successful Successful Very successful 1 2 3 4 5 Which of the following you think that your company needs to do in order to manage its supply chain better? Tick all that apply. Improve Start Implementing Satisfied already Not appropriate Close partnership with suppliers Close partnership with customers JIT supply e-procurement EDI Outsourcing Subcontracting 3PL Plan strategically Supply Chain Benchmarking Vertical integration Few suppliers Many suppliers Holding safety stock Use of external consultants Other (specify) Does your company have a clear logistics strategic plan? YES NO Part 3 Theme 2 What types of systems are currently in use in your company to support Supply Chain Management? Custom-made Standard package Not in use Material Requirements Planning (MRP) Manufacturing Resources Planning (MRPII) Enterprise Resource Planning (ERP) Warehouse Management System (WMS) Supply Chain Management (SCM) Customer Relationships Management (CRM) Supplier Relationships Management (SRM) Advanced Planning System (APS) Just In Time (JIT) Other (specify) How much did you actually benefit from using these systems? Not at all Little Average Greatly A lot Dont know (1) (2) (3) (4) (5) Better quality of information Better quantity of information Flexibility Reduced lead-time in production Cost saving Forecasting Resource planning Better operational efficiency Reduced inventory level More accurate costing Increased coordination between departments Increased coordination with suppliers Increased coordination with customers Increased sales Better quality of information Better quantity of information Flexibility In what level your company is facing the problems below when using SCM systems? No problem at all Little problem Some problem Significant problem Serious problem Dont know (1) (2) (3) (4) (5) Resistance to change from employees Insufficient vendor support Hidden cost Integration with existing system Integration with suppliers system Integration with customers system Other (specify) What types of systems do you plan to implement in the near future (within the next 2 years)? Custom-made Standard package Not going to implement E-commerce E-business Decision support / expert system Radio Frequency Identification (RFID) Bar coding Other (specify) Part 4 Theme 3 19 How satisfied are you with the current public policy regarding SCM and IT? Not at all Somewhat Satisfied Quite satisfied Very satisfied 1 2 3 4 5 How important are the following future measures for supporting your company effort in SCM and IT? Not at all somewhat important important quite important very important (1) (2) (3) (4) (5) More education, e.g. formal qualification More funding and financial support Better infrastructure e.g. telecommunications, road, etc Improved information provision Increased regional cooperation between institutions, e.g. chamber of commerce Closer cooperation between companies and governments Other (specify)

Henri de Toulouse-Lautrec Essay -- Visual Arts Paintings Art

Henri de Toulouse-Lautrec Henri de Toulouse-Lautrec was arguably the greatest graphic artist of his time; he is best remembered for his bold, colourful posters of Parisian entertainers. His childhood years were spent at his family chateau in the southwest of France where he broke both of his legs and therefore stunted his growth. This left him ill proportioned and dwarfish. This unfortunate event probably helped his artistic ability as he spent most of his time on his own. Lautrec was at his peak as a painter and poster artist in the early 1890's at the time of the post impressionists. During his life Lautrec felt most comfortable in the nightclubs, dance halls and brothels of Paris. The narrow life he led is clearly shown in the art that he produced. Lautrec was best renowned for his paintings of the Moulin Rouge and other Parisian entertainers. Lautrec was not the first artist to make the Parisian entertainers serious subjects to paint, Edouard Manet and Edgar Degaswere among the first to paint the Paris nightlife and others soon followed their lead like Lautrec. Although Lautrec's many paintings looked spontaneous and carefree he as never "slapdash" as in he was never messy or careless. He was in fact a dedicated craftsman who knew a lot about the technical matters of his work, especially printmaking. Even after a rough night he would be up to supervise the printing of his lithographs bright and early. Lautrec always carried a small sketchbook with him so he could quickly draw or sketch whatever caught his attention and today thousands of his rapid drawings still survive in the original sketchbooks. He has also reached the elevated position of a dead artist where there is a museum dedicated to him and his work in Albi, France close to where he was born near Toulouse. In the actual paintings of his sketches he tried to keep the spontaneity of the first sketch and therefore liked to work quickly. To work fast he liked to use paint that was thinned considerably with turpentine, which was called peinture a l'essence, which allowed him to so called 'draw with the brush'. He also liked to use absorbent cardboard instead of canvas so the paint would dry quicker and therefore could maintain his momentum. Most painters have a trademark technique and Lautrec's trademark was the printmaking technique called 'crachis' or ... ...reas before this addition the painting must have been a restrained and balanced masterpiece. The unidentified redhead sitting at the table is wearing an exotic headdress that stands out magnificently against her red hair. If you look at each person they each have a distinctive hat or hairstyle as Lautrec was fascinated by different styles of headwear. The mirrored background that lines the walls gives the painting an undefined background so the silhouetted figures stand out boldly in the mirror. I liked this painting because it shows the somewhat quiet of the normally busy Moulin Rouge. The way Lautrec contrasted the brightly painted woman and the redhead at the forefront of the painting with the blacks and browns of the background also attracted me. I also admired the way Lautrec maintained the spontaneity all through his work. My favourite painting of the two that I have talked about is 'At the Moulin Rouge' because I think that this one looks more difficult to paint than 'At the Circus Fernando' as it is in greater detail and most importantly I think it looks better. But take nothing away from 'At the Circus Fernando' as this is also a brilliant piece of art.

Dante Alighieri’s Divine Comedy :: Divine Comedy Inferno Essays

Divine Comedy Dante Alighieri’s Divine Comedy is said to be the single greatest epic poem of all time. The opening story of the character of Dante the Pilgrim is told in the first of the three divisions: The Inferno. The Inferno is a description of Dante’s journey down through Hell and of the several degrees of suffering and many mythical creatures that he encounters on the way. Throughout his travel Dante displays many different feelings and actions but the emotion that summarizes the entire poem is fear. While some of his character traits change as his mind matures and acknowledges the justice being carried out, from the very beginning until the final Canto, his fear does not subside. This does well to reinforce the symbolism of Dante as Everyman and serves to direct the reader to the moral purpose of Divine Comedy, because of the humility and dependence upon God that fear produces. In the first Canto, which serves as an introduction to the entire comedy, Dante encounters the three beasts which impede his progress out of the dark woods. Coming upon the She-Wolf he writes: "This last beast brought my spirit down so low / with fear that seized me at the sight of her, / lost all hope of going up the hill" (I.52-54). Dante is so shaken by the appearances of the three beasts that he rushes headlong into the dark woods he has just come out of. This is only the first obstacle Dante encounters, but it proves an insurmountable one. When Dante and Virgil reach the gate of Hell, Dante is overcome with fear upon reading the inscription above the gate and hearing the screams and lamentations of those inside. He reacts to the inscription by crying out, " ‘Master,’ I said, ‘these words I see are cruel.’ " (III.12). By this he shows his fear of the unknown because he does not yet know exactly what he will witness during his descent. One of Dante’s truest display of fear occurs upon reaching the vile City of Dis. When the "fallen angels" deny the travelers access through the city, Virgil, usually unflappable, even appears shaken up. Understandably, this does not help Dante’s nerves at all. He actually makes a side comment to the reader declaring the terror he felt after the angels had defied Virgil’s request saying: "And now, my reader, consider how I felt / when those foreboding words came to my ears! / I thought I’d never see our world again!" (VIII. Dante Alighieri’s Divine Comedy :: Divine Comedy Inferno Essays Divine Comedy Dante Alighieri’s Divine Comedy is said to be the single greatest epic poem of all time. The opening story of the character of Dante the Pilgrim is told in the first of the three divisions: The Inferno. The Inferno is a description of Dante’s journey down through Hell and of the several degrees of suffering and many mythical creatures that he encounters on the way. Throughout his travel Dante displays many different feelings and actions but the emotion that summarizes the entire poem is fear. While some of his character traits change as his mind matures and acknowledges the justice being carried out, from the very beginning until the final Canto, his fear does not subside. This does well to reinforce the symbolism of Dante as Everyman and serves to direct the reader to the moral purpose of Divine Comedy, because of the humility and dependence upon God that fear produces. In the first Canto, which serves as an introduction to the entire comedy, Dante encounters the three beasts which impede his progress out of the dark woods. Coming upon the She-Wolf he writes: "This last beast brought my spirit down so low / with fear that seized me at the sight of her, / lost all hope of going up the hill" (I.52-54). Dante is so shaken by the appearances of the three beasts that he rushes headlong into the dark woods he has just come out of. This is only the first obstacle Dante encounters, but it proves an insurmountable one. When Dante and Virgil reach the gate of Hell, Dante is overcome with fear upon reading the inscription above the gate and hearing the screams and lamentations of those inside. He reacts to the inscription by crying out, " ‘Master,’ I said, ‘these words I see are cruel.’ " (III.12). By this he shows his fear of the unknown because he does not yet know exactly what he will witness during his descent. One of Dante’s truest display of fear occurs upon reaching the vile City of Dis. When the "fallen angels" deny the travelers access through the city, Virgil, usually unflappable, even appears shaken up. Understandably, this does not help Dante’s nerves at all. He actually makes a side comment to the reader declaring the terror he felt after the angels had defied Virgil’s request saying: "And now, my reader, consider how I felt / when those foreboding words came to my ears! / I thought I’d never see our world again!" (VIII.

Autobiography of a Face, by Lucy Grealy Essay -- The Search for Unatta

In her memoir, Autobiography of a Face, Lucy Grealy tells the story of how the deformities caused by her cancer forced her into a life of isolation, cruel insults, and unhappiness. Grealy clearly demonstrates how a society that excessively emphasizes female beauty can negatively affect a young girl, especially one with a deformity. Most interpret this story as a way for Grealy to express the pain that she endured because she did not measure up to society’s definition of female beauty, a standard that forces girls into unhealthy habits, plastic surgery, and serious depression. In the afterword of the memoir, Grealy’s friend, Ann Patchett, tries to change this interpretation by saying that Grealy never meant for it to be a story of the hardships she faced as a young girl with a deformity; she simply wished it to be viewed â€Å"as a piece of literature.† (232). However, this short passage takes away from the important message that Grealy expresses in h er memoir: that the unattainable standards of female beauty in society can destroy the joy and livelihood of young girls. Grealy understandably denied this as her reason for writing because, to her, admitting that the story of her life was dominated by her deformity would be like admitting that she had never lived. She frequently explains in her memoir that she longed for physical beauty so that she could finally live without isolation and dejection. To label her memoir a story of loneliness and sorrow would be admitting that she never reached this sense of beauty she so strongly desired. Despite Ann Patchett’s interpretation of the memoir, it should still be seen as a story demonstrating how society’s unreachable standards of beauty can deprecate the lives of young girls, as ... ...t of sexes becomes more equal, young men may begin to develop the habits of young women who try so hard to live up to a perfect standard of beauty. This issue should not and cannot be ignored, and correct acknowledgement of stories like Grealy’s will tighten opportunities for young women to preserve and cherish what really makes them beautiful. Works Cited "A Conversation With Lucy Grealy." Charlie Rose. Web. 5 Mar 2010. Graydon, Shari. "How the Media Keeps Us Hung Up on Body Image." Herizons 22.1 (2008): n. pag. Web. 5 Mar 2010. Grealy, Lucy. Autobiography of a Face. New York: Houghton Mifflin Company, 1994. Print. Kruger, Paula. "1 in 5 Girls Display Eating Disorder Behaviour." ABC News . 20 Jul 2007. ABC, Web. 5 Mar 2010. Sweeney, Camille. "Seeking Self-Esteem Through Surgery." New York Times 14 Jan 2009: n. pag. Web. 5 Mar 2010.

Healthy and unhealthy habits Essay

Have you ever wondered, why people do and enjoy bad habits and they know its bad for them? there are danger, damages and effects that people don’t know about bad habits. according to www. wikihow. com, some habits can have serious consequences for our health, such as dangerous deadly heart attacks. and I think that people who have bad habits should realize that they are making fun of death itself. Can you imagine your self lonely, anti-social and unlovable? well, for your info’s, bad habits can cause all of these issues,because a lot of bad habits make you anti-social, also some of them lead to early death, yes early death. beside, do you think that bad habits can make you happy more than sad? i bet you don’t, and i know that changing bad habits is really really hard, and i know how much it take to change them, but being surrounded with friends and family is much better than bad health and loneliness! i know a story about a kid who lost everything, Kareem was a conceited kid, his parents gave him a lot of money and love thinking that he is a good kid, he met bad friends who have bad habits, they taught him how to drink and get drugs, by the days, his parents noticed that he come late to home, and the school too, and he started to say bad words, then, they found out that he was taking drugs, they took him to the hospital, and they healed him, but when he got out, he was trying to find a source of money, because his parents no longer giving him money like before, so he went to his loving grandmother, and he killed her for money, what a poor grandmother, after days, the police found him, and took him to the jail, and this kid learned his lesson, that bad friends wont help him if he got in troubles, and bad habits cant make him happy. Being healthy, happy and having a perfect life is so easy, and i will tell you how. healthy habits can change your life, in addition to that, healthy habits can make you have a fit perfect body, and it can improve your IQ level, improve your skin health, improve your mood and protect you from diseases like heart diseases. First step is learning, learn what are the healthy habits we need everyday, like drinking 8 cups of water everyday, because we lose 4 liters of water by sweating etc. the second step, stick them into your daily routine, if you did, it will no longer be hard for you, final step, see the result, and live a healthy better life. well, i realize that these steps may seem easy, but they are not like what you think they are, some people said that having healthy habits is hard, its hard for us people to change our routine. some people couldn’t do that because they love their bad habits, they love their daily chips, they love their laziness in front of the T. V, but let me tell you something, they think with the short period thinking brain,their brain say to them ( its okay, its just a little piece of pizza, its just a coke, its just a blah blah blah) but, its not just like that, no, they become fatter and fatter and fatter and they don’t realize it until their health become bad, and thats why we should try to have healthy habits. UAE these days is trying to be the best country compared with other countries. don’t we want to see our country name in every wear? don’t we? so lets start with our self. i get really mad and angry for seeing my brothers and sisters in UAE have bad health, and deeply in my heart, i pray for them, as me, i want everyone in UAE to have healthy habits, because i understand that happiness come from healthy lifestyle, and with healthy lifestyle, we become stronger, and we have a clear mind, and that all lead to much more productive society, and the results will show up in our country, and it’ll raise more and more, and our country UAE will be the best of all. Bad habits are bad friends, we have fun with them, then when we get in troubles, they walk away. people should know that their happiness is the payment for their wasted health, and there is nothing more that worth than health. lets all work together, and start from today, lets change our bad habits to healthy, and lets protect our families and loved once from these serious consequences!

Personal Growth and Development

Psychology 101 TuThu 3:30-4:45 The concept of personal development has been an important factor that shapes the characters we develop, and the overall person we become. Research suggests that many of the values and traits we possess stem from both genetics and the environment. In terms of genetics, hereditary traits are passed down from the mother and father, which play a huge role in personal development, but research and personal experience also suggest that the impact of the environment parallels the importance of genetics.Environmental factors have been proven to significantly impact the growth and development of an individual. The home the individual is raised in, the people they are surrounded by and the individual’s role model all play an important role in the molding of the individual. Such is the reason why cultural relativism impacts individuals, and guides the way they perform tasks, execute decisions, and their way of thought. The American culture, for example, has slowed down the transition of adolescence into adulthood due to cultural ideals, and the greater need to pursue a higher education in order to compete successfully in the country.Research by the 1958 National Child Development Study, and the 1970 British Cohort Study support these statements, and have shown that we have reached a generation in which adolescents are transitioning into adulthood more slowly, yet more psychological stress is placed on them, and reports of depression have raised since the 50s. Personal growth and development traces back to genetics. Each individual is born with a specific set of genes depending on the mother and father.Genetic traits such as weight, height, appearance, and in some cases, personality, are passed down the hereditary line, and predisposes individuals to certain traits and qualities. The health of the individual is also largely influenced by the care taken by the mother while the fetus was developing within the womb. Proper nutrition, and avoiding neglectful habits such as drinking and smoking, all help to shape the health of the individual from the time they are born. The environment we are raised in is also another factor in the shape and development of an individual.Take for instance the study that examined how environment affects individuals such as siblings, twins, and kids not related by blood, but raised in the same environment. It is shown that even twins who exited the womb during the same birth can come out profoundly different in their adulthood if they were raised in a different environment from their twin. The food that we eat, the habits that we employ, and the overall lifestyle of the individual play an important role as well as genetics.Two similar children who are raised in different environments may possess the same genetic traits, but overall can be distinguished by the environment they were raised in. Cultural relativism plays a role as well in the well-being of the individual. Being raised in Ame rica sets a different standard for living vs. being born elsewhere. In America, individuals are taught to be creative and unique, rather than conform to group ideals. It is in this culture that children are taught to employ creative ideas, and to break away from the grain.In other cultures, such as those in China, kids are raised to follow the grain, and rather than question elders and peers, are taught to accept what is given and told to them. With that in mind, the transition into adulthood has also slowed down due to various factors such as cultural acceptance, and the need to pursue a higher education in order to be more competitive in the job market. As the years pass, so does the standard of education raise as more occupations open up to individuals with special skills and knowledge achieved through a higher education in college.Although this slower transition into adulthood and independence may seem less stressful for individuals, studies from the British Cohort Study show th at individuals in the 70s vs. the 50s reported more cases of depression, and stress due to factors such as economic recessions which hindered the job market availability. This generation is especially pressed to reach higher educational goals as the market for unskilled labor reduces as the market for skilled labor increases hindering the transition into adulthood and independence.In conclusion, personal development and growth are influenced by several factors such as genetics, environment, cultural relativism. These factors shape an individual in specific ways. Genetics passed on influence one’s height, personality, and predispositional thinking that affect the person in everyday situations. Proper health from the time the embryo is implanted is necessary for a healthy baby. The environment also plays a role in the shaping of the individual. The home one was raised in, the nutrition, and overall lifestyle impact the health and behavior of a person.Cultural relativism also pl ays a role, as culture follows an individual around regardless of location, and influences what one finds acceptable, and follows due to social norms. Because of the need for a higher education in today’s job market, a slower transition into adulthood can be traced to the need for more schooling, and a slower transition to independence.References Spiro, Melford E. (2001). Cultural determinism, cultural relativism, and the comparative study of psychopathology. Ethos. Berkeley:. Vol. 29, Iss. 2; pg. 218, 17 pgs. Huffman, Karen (2010). Life Span Development I. John Wiley and Sons, Psychology in Action 314-347. Personal Growth and Development Personal Development and Growth Zoheb Osmani Psychology 101 TuThu 3:30-4:45 The concept of personal development has been an important factor that shapes the characters we develop, and the overall person we become. Research suggests that many of the values and traits we possess stem from both genetics and the environment. In terms of genetics, hereditary traits are passed down from the mother and father, which play a huge role in personal development, but research and personal experience also suggest that the impact of the environment parallels the importance of genetics.Environmental factors have been proven to significantly impact the growth and development of an individual. The home the individual is raised in, the people they are surrounded by and the individual’s role model all play an important role in the molding of the individual. Such is the reason why cultural relativism impacts individuals, and guides the way they perform tasks, execute decisions, and their way of th ought. The American culture, for example, has slowed down the transition of adolescence into adulthood due to cultural ideals, and the greater need to pursue a higher education in order to compete successfully in the country.Research by the 1958 National Child Development Study, and the 1970 British Cohort Study support these statements, and have shown that we have reached a generation in which adolescents are transitioning into adulthood more slowly, yet more psychological stress is placed on them, and reports of depression have raised since the 50s. Personal growth and development traces back to genetics. Each individual is born with a specific set of genes depending on the mother and father.Genetic traits such as weight, height, appearance, and in some cases, personality, are passed down the hereditary line, and predisposes individuals to certain traits and qualities. The health of the individual is also largely influenced by the care taken by the mother while the fetus was devel oping within the womb. Proper nutrition, and avoiding neglectful habits such as drinking and smoking, all help to shape the health of the individual from the time they are born. The environment we are raised in is also another factor in the shape and development of an individual.Take for instance the study that examined how environment affects individuals such as siblings, twins, and kids not related by blood, but raised in the same environment. It is shown that even twins who exited the womb during the same birth can come out profoundly different in their adulthood if they were raised in a different environment from their twin. The food that we eat, the habits that we employ, and the overall lifestyle of the individual play an important role as well as genetics.Two similar children who are raised in different environments may possess the same genetic traits, but overall can be distinguished by the environment they were raised in. Cultural relativism plays a role as well in the well -being of the individual. Being raised in America sets a different standard for living vs. being born elsewhere. In America, individuals are taught to be creative and unique, rather than conform to group ideals. It is in this culture that children are taught to employ creative ideas, and to break away from the grain.In other cultures, such as those in China, kids are raised to follow the grain, and rather than question elders and peers, are taught to accept what is given and told to them. With that in mind, the transition into adulthood has also slowed down due to various factors such as cultural acceptance, and the need to pursue a higher education in order to be more competitive in the job market. As the years pass, so does the standard of education raise as more occupations open up to individuals with special skills and knowledge achieved through a higher education in college.Although this slower transition into adulthood and independence may seem less stressful for individuals, studies from the British Cohort Study show that individuals in the 70s vs. the 50s reported more cases of depression, and stress due to factors such as economic recessions which hindered the job market availability. This generation is especially pressed to reach higher educational goals as the market for unskilled labor reduces as the market for skilled labor increases hindering the transition into adulthood and independence.In conclusion, personal development and growth are influenced by several factors such as genetics, environment, cultural relativism. These factors shape an individual in specific ways. Genetics passed on influence one’s height, personality, and predispositional thinking that affect the person in everyday situations. Proper health from the time the embryo is implanted is necessary for a healthy baby. The environment also plays a role in the shaping of the individual. The home one was raised in, the nutrition, and overall lifestyle impact the health and beh avior of a person.Cultural relativism also plays a role, as culture follows an individual around regardless of location, and influences what one finds acceptable, and follows due to social norms. Because of the need for a higher education in today’s job market, a slower transition into adulthood can be traced to the need for more schooling, and a slower transition to independence.References Spiro, Melford E. (2001). Cultural determinism, cultural relativism, and the comparative study of psychopathology. Ethos. Berkeley:. Vol. 29, Iss. 2; pg. 218, 17 pgs. Huffman, Karen (2010). Life Span Development I. John Wiley and Sons, Psychology in Action 314-347.