Four Stroke Four Cylinder Petrol Engine

Four Stroke Four Cylinder Petrol Engine ABSTRACT Since last 150 years different type of engine used in different vehicles so one should know how the engine works and different parameters related to it. This project contains preparation of experimental setup to determine the various performance parameter of four stroke four cylinder petrol engine in first stage of project. In this stage of project, the Morse test setup with Rope brake dynamometer will be prepared for the measurement of engine performance parameters such as Break power, Indicated power, Friction power, Mass flow rate, Brake thermal efficiency, etc. In the second stage study of existing engine and scuderi split engine to be done and effort will be done to develop scuderi split engine. Since last 150 years no modification has been done for basic engine design. This scuderi split engine completely change the design structure of engine. CHAPTER 1 INTRODUCTION Project on EXPERIMENTAL SETUP FOR PERFORMANCE MEASUREMENT OF FOUR STROKE FOUR CYLINDER PETROL ENGINE DEVELOPEMENT OF SCUDERI SPLIT ENGINE consist of two stages. In first stage of the project, experimental setup for 4-cylinder petrol engine (Morse test) will be developed to determine the various engine performance parameters such as Break power, Indicated power, Friction power, Mass flow rate, Brake thermal efficiency, etc. The basic task in the design and development of engines is to reduce the cost of production and improve the efficiency and power output. In order to achieve the above task, the development engineer has to compare the engine developed with other engines in terms of its output and efficiency. Towards this end he has to test the engine and make measurements of relevant parameters that reflect the performance of the engine. For this the various test perform on engine are as follow: Willans line method Morse test Motoring test From the measurement of indicated and brake power Retardation test From this set-up of Morse test is simple and comparatively easy to conduct. Here, Rope brake dynamometer is used to measure power output. In second stage of project, the study of the scuderi split engine will be done comparison of it with conventional engine (4-S 4 Cylinder Petrol engine of Fiat Make). In conventional 4 Stroke engine, four strokes such as intake, compression, power exhaust performed in the single cylinder. While in scuderi split engine above Strokes performed in two cylinder which are connected using cross-over passage, in which pressure remains constant, in which two stroke intake compression take place in First cylinder, remaining stroke power exhaust take place in Second cylinder. CHAPTER 2 LITERATURE SURVEY 2.1 Introduction: The internal combustion engine is an engine in which combustion of fuel and an oxidizer (typically air) occurs in a confined space called a combustion chamber. This exothermic reaction creates gases at high temperature and pressure which are permitted to expand. The defining feature of an internal combustion engine is that useful work is performed by the expanding hot gases acting directly to cause movement of solid parts of the engine, by acting on pistons, rotors, or even by pressing on and moving the entire engine itself. The first internal combustion engines did not have compression, but run on air/fuel mixture sucked or blown in during the first part of the intake stroke. The most significant difference between modern internal combustion engines and the early designs was the use of compression and in particular of in-cylinder compression. 1876: Nikolaus Otto working with Gottlieb Daimler and Wilhelm Maybach had developed a practical four-stroke cycle (Otto cycle) engine. 2.2. Application of I.C. engine:- Internal combustion engines are most commonly used for mobile propulsion in automobiles, equipment, and other portable machinery. In mobile equipment internal combustion is advantageous, since it can provide high power to weight ratios together with excellent fuel energy-density. These engines have appeared in transport in almost all automobiles, trucks, motorcycles, boats, and in a wide variety of aircraft and locomotives, generally using petroleum (called All-Petroleum Internal Combustion Engine Vehicles or APICEVs) . Where very high power is required, such as jet aircraft, helicopters and large ships, they appear mostly in the form of turbines. 2.3. Classification of I.C. Engine:- The internal combustion engine may be classified in many ways, but following are the subject point of view: 1) According to the type of fuel used (a)Petrol engine (b)Diesel engine (c)Gas engine 2) According to the method of igniting the fuel (a)Spark ignition engine (b)Compression ignition engine (c)Hot spot ignition engine 3) According to the number of stroke per cycle (a)Four stroke cycle engine (b)Two stroke cycle engine 4) According to the cycle of operation (a)Otto cycle (b)Diesel cycle (c)Dual cycle 5) According to the speed of the engine (a)Slow speed engine (b)Medium speed engine (c)High speed engine 6) According to the cooling system (a)Air cooled engine (b)Water cooled engine (c)Evaporative cooling engines 7) According to method of fuel injection (a)Carburettor engine (b)Air injection engines (c)Airless or solid injection engines 8) According to number of cylinder (a)Single cylinder engines (b)Multi cylinder engines 9) According to arrangement of cylinder (a)Vertical cylinder engines (b)Horizontal cylinder engines (c)Radial engines (d)In-line multi cylinder engines (e)V-type multi-cylinder engines (f)Opposite-cylinder engines (g)Apposite piston engines 10) According to the valve mechanism (a)Overhead valve engines (b)Side valve engines 11) According to the method of governing (a)Hit and miss governed engines (b)Quantitatively governed engines (c)Qualitatively governed engines 2.4 Basic Engine Parts:- 2.4.1 Cylinder block:- The cylinder block is the main supporting structure for the various components. The cylinders of multi-cylinder engine are cast as single unit, called cylinder block. The cylinder head mounted on the cylinder block .The cylinder head and cylinder block are provided with water jacket for cooling. 2.4.2 Cylinder:- As the name implies it is a cylindrical vessel or space in which the piston makes a reciprocating motion. The varying volume created in the cylinder during the operation of the engine is filled with the working fluid and subjected to different thermodynamics processes such as suction, compression, combustion, expansion and exhaust .The cylinder is supported in cylinder block. 2.4.3 Combustion chamber:- The space enclosed in the upper part of the cylinder, by the cylinder head and the piston top during the combustion process, is called the combustion chamber. 2.4.4. Piston: Piston is the heart of the engine. The functions of the piston are to compress the charge during the compression stroke and to transmit the gas force to the connecting rod and then to the crank during power stroke. The piston is a disc which reciprocates within cylinder. It is either moved by the fluid or it moves the fluid which enters the cylinder. The main function of the piston of an internal combustion engine is to receive the impulse from the expanding gas and to transmit the energy to the crankshaft through the connecting rod. The piston of internal combustion engines are usually of trunk type. This type of piston consists of different parts such as Head or Crown, Piston rings, Skirt, Piston pin etc. 2.4.5. Piston Ring: Piston rings provide a sliding seal between the outer edge of the piston and the inner edge of the cylinder. The rings serve two purposes: 1. They prevent the fuel/air mixture and exhaust in the combustion chamber from leaking into the sump during compression and combustion. 2. They keep oil in the sump from leaking into the combustion area, where it would be burned and lost. A piston ring is an open-ended ring that fits into a groove on the outer diameter of a piston in an internal combustion engine. The gap in the piston ring compresses to a few thousandths of an inch when inside the cylinder bore. 2.4.6 Inlet manifold:- The pipe which connects the intake system to the inlet valve of the engine and through which air or air-fuel mixture is drawn in to the cylinder is called inlet manifold. 2.4.7 Exhaust manifold:- The pipe which connects the exhaust system to the exhaust valve of the engine and through which the product of combustion escape in to the atmosphere is called the exhaust manifold. 2.4.8 Inlet and exhaust valve:- Valves are commonly mushroom shaped poppet type. They are provided either on the cylinder head or on the side of the cylinder for regulating the charge coming in to the cylinder (inlet valve) and for discharging the products of combustion from the cylinder (exhaust valve). 2.4.9. Connecting Rod: The connecting rod connects the piston to the crankshaft. It can rotate at both ends so that its angle can change as the piston moves and the crankshaft rotates. The small end attaches to the piston pin, gudgeon pin (the usual British term) or wrist pin, which is currently most often press fit into the con rod but can swivel in the piston, a floating wrist pin design. The big end connects to the bearing journal on the crank throw, running on replaceable bearing shells accessible via the con rod bolts which hold the bearing cap onto the big end; typically there is a pinhole bored through the bearing and the big end of the con rod so that pressurized lubricating motor oil squirts out onto the thrust side of the cylinder wall to lubricate the travel of the pistons and piston rings. 2.4.10. Spark Plug: The spark plug supplies the spark that ignites the air/fuel mixture so that combustion can occur. The spark must happen at just the right moment for things to work properly. 2.4.11. Crank shaft: The crankshaft turns the pistons up and down motion into circular motion just like a crank on a jack-in-the-box does. The crankshaft, sometimes casually abbreviated to crank, is the part of an engine which translates reciprocating linear piston motion into rotation. It typically connects to a flywheel, to reduce the pulsation characteristic of the four-stroke cycle, and sometimes a torsional or vibrational damper at the opposite end, to reduce the torsion vibrations often caused along the length of the crankshaft by the cylinders farthest from the output end acting on the torsional elasticity of the metal. 2.4.12. Cam shaft:- The camshaft and its associated parts control the opening and closing of the two valves. The associated parts are push rods, rocker arms, valve springs and tappets. This shaft also provides the drive to the ignition system. 2.4.13. Gudgeon pin: It forms the link between the small end of the connecting rod and the piston. 2.4.14. Cam:- These are made as integral parts of the camshaft and are designed in such way to open the valves at the correct timing and to keep them open for necessary duration. 2.4.15. Fly wheel: The net torque imparted to crankshaft during one complete cycle of operation of the engine fluctuates causing a change in the angular velocity of the shaft. In order to achieve a uniform torque an inertia mass in the form of a wheel attached to the output shaft and this wheel is called the flywheel. 2.4.16. Sump:- The sump surrounds the crankshaft. It contains some amount of oil, which collects in the bottom of the sump (the oil pan). 2.5. DIFFERENT TYPES OF MATERIAL USE FOR ENGINE PARTS:- 2.5.1. Cylinder liner: The cylinder liners are made in two types: wet liner dry liner. In case of wet liner, water in jacket is in direct contact with the outer wall of the liner; where as the dry liner is pressed into the cylinder proper. In engines over about 13cm bore; usually the wet type of liner is used. Liner materials: The liner material should be strong hard corrosion resistance. The following materials are used. 1. A good grade grey cast iron with homogenous and close grained structure i.e. prelatic and similar cast iron. 2. Nickel cast iron and nickel chromium cast iron 3. Nickel chromium cast steel with molybdenum in some case. 2.5.2. Material of cylinder head:- The cylinder head are usually made of close grained cast iron or alloy cast iron containing nickel, chromium and molybdenum, for small sized engine, while for large engine, the material is low Cast-steel. 2.5.3. Material used for piston piston ring:- Commonly used materials for piston of I.C. engine are cast iron, cast aluminum, cast steel forged steel. Generally cast steel is used for piston head. The material for the piston ring is cast iron alloy cast iron due to their good wearing qualities also they retain the spring characteristics even at high temperature. The material used for piston ring is nitrogen hardened or case hardened steel alloy containing nickel, chromium, molybdenum or vanadium. 2.5.4. Material used for connecting road:- The connecting rods of I.C.engine are mostly manufactured by drop forging. The material for connecting rod ranges from mild or medium carbon steel to alloy steels. In industrial engine, carbon steel with ultimate tensile strength ranging from 550-670Mpa is used. 2.5.5. Material used for crankshaft: The cylinder head are usually made of close grained cast iron or alloy cast iron containing nickel, chromium and molybdenum, for small sized engine, while for large engine, the material is low C-steel. Heavy duty cast iron, cast steel, nickel chromium steel is mainly used for manufacturing of crank shaft. 2.5.6. Material used for valves: Inlet valve run cooler than exhaust valves. So, the material for the inlet valves may be carbon steel, nickel steel, chrome nickel steel chrome molybdenum alloy, which may be hardened to withstand the repeated high stresses. Material for exhaust valves must be able to maintain their strength at high temperature. Therefore the material used for it is standard chrome nickel steel, cobalt nickel steel, high speed steel stainless steels. 2.6 NOMENCLATURE:- 2.6.1 Cylinder bore (d): The nominal inner diameter of the working cylinder is called the cylinder bore. It is expressed in millimeter (mm). 2.6.2 Piston area: The area of the circle of diameter equal to the cylinder bore is called the piston area. It is expressed by square centimeter (cm ²). 2.6.3 Stroke (L): The nominal distance through which a working piston moves between two successive reversals of its direction of motion is called the stroke is expressed in millimeter (mm). 2.6.4 Stroke to bore ratio: L/d ratio is an important parameter in classifying the size of the engine. If d If d=L, it is called square engine. If d>L, it is called over -square engine. An over square engine can operate at higher speeds because of large bore shorter stroke. 2.6.5 Dead center: The position of the working piston the moving parts which are mechanically connected to it, at the moment when the direction of the piston motion is reversed at either end of the stroke is called the dead center. There are two dead centers in the engine: Top dead center (TDC): It is the dead centers when the piston is farthest from the crankshaft. It is designated TDC for vertical engines inner dead center (IDC) for horizontal engines. Bottom dead center (BTC): It is the dead center when the piston is nearest to the crankshaft. It is designated as BDC for the vertical engines outer dead center (ODC) for horizontal engines. 2.6.6 Displacement or Swept volume: The nominal volume swept by the working piston when traveling from one dead center to other is called the displacement volume. It is expressed in terms of cubic centimeter (cc) given by VS = à Ã¢â€š ¬d ²L/4 2.6.7 Cubic Capacity of Engine Capacity: The displacement volume of a cylinder multiplied by number of cylinders in an engine capacity. For example, if there are K cylinders in an engine, then Cubic capacity = Vs x K 2.6.8 Clearance Volume (Vc): The nominal volume of the combustion chamber above the piston when it is at the top dead centre is the clearance volume. It is designated as Vc and expressed in cubic centimeter (cc). 2.6.9 Compression Ratio (r): it is the ratio of the total cylinder volume when the piston is at the bottom dead centre, Vt, to the clearance volume, Vc. It is designed by the letter r. r = Vt/Vc = (Vc + Vs)/Vc = 1 + Vs/Vc CHAPTER 3 WORKING OF AN I.C. ENGINE I.C. engine is a device which develops the work continuously taking the working fluid through cyclic process. The combination of piston and cylinder is suitable device for developing the work. In an arrangement of piston and cylinder of an ideal engine, following for process constitute the cycle: The air is compressed in the engine. Heat is added to the compressed air by external source. High pressure and high temperature air expands performing the work. The air after expansion returns to the original condition by rejecting heat to external sink. 3.1 The working principle of four-stroke spark ignition engine:- If an engine is to work successfully then it has to follow a cycle of operation in sequential manner. The sequence is quite rigid and can not be changed. In the following sections the working principle of both SI and CI engines is described. Even though both engines have much in common there are certain fundamental differences. The cycle of operation for an ideal four-stroke SI engine consist of the following four-stroke:- 1. Intake or suction stroke 2. Compression stroke 3. Power or expansion stroke 4. Exhaust stroke Intake or suction stroke :- Suction stroke starts when the piston is at the top dead centre and about to move downwards. The inlet valve is open at this time and exhaust valve is closed. Due to the suction created by the motion of the piston towards the bottom dead centre, the charge consisting of fuel-air mixture is drawn in to the cylinder. When the piston reaches the bottom dead centre the suction stroke ends and the inlet valve closes. compression stroke :- The charge taken in to the cylinder during the suction stroke is compressed by the return stroke of the piston. During this stroke both inlet and exhaust valves are in closed position. The mixture which fills the entire cylinder volume is now compressed in to the clearance volume. At the end of the compression stoke the mixture is ignited with the help of a spark plug located on the cylinder head. During the burning process the chemical energy of the fuel is converted in to heat energy producing temperature rise of about 2000 °C.The pressure at the end of the combustion process is considerably increased due to the heat release from the fuel. Expansion or power stroke :- The high pressure of the burnt gases forces the piston towards BDC. Both, the valves are in closed position .Of the four stroke only during this stroke power is produced. Both pressure and temperature decrease during expansion. Exhaust stroke :- At the end of the expansion stroke exhaust valve opens and inlet valve remains closed. The pressure falls to atmospheric level a part of the burnt gases escape. The piston starts moving from the bottom dead centre to top dead centre and sweeps the burnt gases out from the cylinder almost at atmospheric pressure. The exhaust valve closes when the piston reaches TDC .At the end of the exhaust stroke and some residual gases trapped in the clearance volume remain in the cylinder. CHAPTER 4 ACTUAL CYCLE FOR I.C.ENGINE DIFFERENCE BETWEEN ACTUAL CYCLE THERMODYNAMIC CYCLE:- The working substance is not air but a mixture of fuel and air during suction and compression and many gases during expansion and exhaust. Combustion of fuel not only adds the heat but changes the chemical composition also. The specific heat of gases changes with respect to temp. The residual gases change the composition, temp. and amount of fresh charge. The constant volume combustion is not possible. Compression and expansion are not isentropic. There is always some heat loss-due to heat transfer from the hot gases to cylinder walls. There is exhaust blow down loss due to early opening of exhaust valve. 4.2 VALVE TIMING DIAGRAM FOR 4-STROKE PETROL ENGINE:- (1) Inlet valve:- The intake valve should open, theoretically, at TDC; almost all SI engines an intake valve opening of a few degrees before TDC on the exhaust stroke. This is to ensure that the valve will be fully open and the fresh charge starts to flow into cylinder as soon as the piston reaches TDC. In figure ( ), the intake valve starts to open 10 o before TDC. As the piston descends on the intake stroke, the fresh charge is drawn in through the intake port and valve. It may be noted from figure ( ), that for a low speed engine, the intake valve closes 10o after BDC, and for a high speed engine, 60o after BDC. If the inlet valve is allowed to close at BDC, the cylinder would receive less charge than its capacity and the pressure of the charge at the end of the suction stroke will be below atmosphere. When the piston reaches BDC and start to ascend on the compression stroke, the inertia of the fresh charge tends to cause it to continue to move into the cylinder. At low engine speeds, the charge is moving into the cylinder relatively slowly, and its inertia is relatively low. If the intake valve were to remain open much beyond BDC, the up moving piston on the compression would tends to force some of the charge, already in the cylinder back into the intake manifold, with consequent reduction in volumetric efficiency. Hence, the intake valve is closed relatively early after BDC for a slow speed engine. For High Speed Engine, Inlet Valve closing is delayed after BDC to take above advantage. (2) Exhaust valve:- The exhaust valve usually opens before the piston reaches BDC on the expansion stroke. This reduces the work done by the expanding gases during power stroke, but decreases the work necessary to expel the burned products during exhaust stroke, and the result in an overall gain in output. During the exhaust stroke, the piston forces the burned gases out at high velocity. If the closing of the exhaust valve is delayed beyond TDC, the inertia of the exhaust gases tends to scavenge the cylinder better by carrying out greater mass of the gas left in the clearance volume, and result in increased volumetric efficiency. Consequently, the exhaust valve is often set to close a few degrees after TDC on the exhaust stroke, as indicated in figure ( ), it should be noted that it is quit possible for both the intake and exhaust valves to remain open, or partially open, at the same time. This is termed the valve overlap. (3) Ignition:- It would be proper to produce spark at the end of compression if the charge could burn instantaneously. How ever, there is always a time lag between the spark and ignition of the charge. The ignition starts some time after giving the spark, it is necessary to produce the spark before piston reaches the TDC to obtain proper combustion without losses. The angle through which the spark is given earlier is known as Ignition advance or Angle of advance 4.3 SOURCES OF LOSSES:- The difference between I.P. B.P. is known as total friction loss. This includes direct mechanical friction throttling losses through valves, pumping loss, blow down losses many others. 4.3.1. Direct frictional losses:- It includes bearing losses, as main bearing, camshaft bearing, and piston cylinder friction loss in many moving parts. The frictional losses are comparatively higher in reciprocating I.C. Engine. 4.3.2. Pumping losses:- The difference of work done in expelling the exhaust gases and the work done by fresh charge during the suction stroke is called the pumping work. In other words loss due to the gas exchange process (Pumping Loss) is due to pumping gas from lower inlet pressure to higher exhaust pressure. The pumping loss increases at part throttle because throttling reduces the suction pressure. Pumping loss increases with speed. The gas exchange processes affect the volumetric efficiency of the engine. 4.3.3. Blow by losses:- This loss because of leakage of combustion products past the piston forms the cylinder into the crank case. This loss depends upon inlet pressure and compression ratio .This loss increase directly with compression ratio but reduced with an increase in the engine speed. 4.3.4. Valve throttling losses:- The standard practice for sizing the exhaust valve is to produce smaller exhaust area than inlet valve area. This increases the pumping loss as smaller area resists more for the flow of exhaust gasses. This increase in speed of the engine rapidly if the valve size, valve timing and valve flow coefficients are not designed properly as shown in fig. by dotted line . The inlet throttling occurs due to the restrictions imposed by air cleaner, carburettor, and venture, throttle valve, inlet manifold and inlet valve. All these add in pressure loss .Similarly some pressure loss occurs during exhausting the burned gases. 4.3.5. Combustion chamber pump losses:- This loss occurs with pre-combustion chamber. This loss occurs due to the pumping work required to push the air into pre-combustion chamber through small orifice. This depends upon orifice size, and speed. It also increases with increasing the engine speed. 4.3.6. Power loss to drive the auxiliaries:- Some power is required to drive the auxiliaries such as water pump, fuel pump, cooling fan generator. This is also considered as loss as part of engine power developed is used for these purposes. 4.3.7. Heat loss factor:- During the combustion process and expansion the heat flows through the cylinder head. Some heat enters the piston and flows through the piston rings into the cylinder wall or is carried away by the engine lubricating oil which splashes on the underside of the piston. The heat loss along with other losses is shown on p-v diagram (Figure ( )). Heat loss during combustion has maximum effect on cycle efficiency while heat loss just before the end of expansion stroke has very little effect because of the contribution of useful work is very little. The heat lost during the combustion doesnt represent the complete loss only about 15% of total heat is lost during combustion expansion. If all the heat loss is recovered only 20% of if may appear as useful work. The effect of loss of heat during combustion is to reduce the maximum temperature and therefore, the specific heats are lower. Heat loss factor contributes around 12% to all their losses 4.3.8. Time loss factor:- In a thermodynamic cycle heat addition is assumed to be instantaneous process where as in actual cycle it is over a definite period of time .the time required for combustion is such that under all circumstances some change in volume takes place while it is in progress. The consequence of finite time of combustion is that peak pressure will not occur when volume is minimum i.e. when the piston at TDC but it will occur sometime after TDC. 4.3.9. Exhaust blow down:- The cylinder pressure at the end of exhaust stroke is about 7 bar depending on the compressor ratio. If the exhaust valve is opened at bottom dead centre the piston has to do work against high cylinder pressure during the part of the exhaust stroke. If the exhaust valve is opened too early, a part of the expansion stroke is lost. The best compromise is to open the exhaust valve 40 to 700 before BDC. Thereby, reducing the cylinder pressure to halfway to atmospheric before the exhaust stroke begins. 4.3.10. Knocking in SI- Engine:- Knocking is due to the auto-ignition of the end portion of the unburned charge in the combustion chamber. As the normal flame front proceeds across the chamber, the pressure the temp of the unburned charge increase due to compression by the burned portion of the charge. This unburned compressed charge may auto ignite under certain temp. Conditions release the energy at a very rapid rate compared to normal combustion process in the cylinder. This rapid release of energy during auto-ignition causes a high pressure differential in the c.c. and a high pressure wave is released from auto-ignition region. The motion of high pressure compression waves inside the cylinder causes vibration of the engine parts and pinking noise and it is known as knocking or detonation. Effect of knocking:- Mechanical damage:- Knocking creates very high pressure wave (200bar) of large amplitude. This increases the rate of wear almost of all mechanical parts like piston, cylinder head, valves. The frequency of this wave is as large as 5000 CPS. (2) Noise:- When the intensity of knock is high, a loud pulsating noise is created because of high intensity pressure wave vibrates back and forth across the cylinder. This noise is like as bell noise. (3) Increase in heat transfer rate:- When the engine is knocking, more heat is lost to the coolant as the dissipating rate increases. The major reason of increases in heat transfer rate during knocking is, the boundary layer of the gas near the wall is removed because of high vibration of gas molecules. (4) Power output:- It is also observed that slightly rated spark develops more power under knocking condition. This may be due to rapid burning of the last part of the charge and retard spark may be optimum under knocking. (5) Pre ignition:- It defined as an ignition of the charge as it comes in contact with hot surface, in the absence of spark. Auto ignition may overheat the spark plug and exhaust valve and it remains so hot that its temp. is sufficient to ignite the charge in the next cycle during the compression stroke before the spark occurs an this causes the pre ignition of the charge. The temperature required for pre i

Municipal Solid Waste Management Essay

Municipal Solid Waste Management Essay Waste management is the collection, transport, processing, recycling or disposal, and monitoring of waste materials. The term usually relates to materials produced by human activity and is generally undertaken to reduce their effect on health, the environment or aesthetics. Waste management is also carried out to recover resources from it. Waste management can involve solid, liquid, gaseous or radioactive substances, with different methods and fields of expertise for each. Waste Management is the term that refers to the collection, processing, recycling, transport, and monitoring of waste products. The waste products means the various materials produced by human activity and is undertaken for reducing their effect on health, environment or aesthetics. Another application of the waste management is to recover the various resources from it. It involves the management of solid, liquid, and gaseous wastes. Each type of waste requires a different methods and fields of expertise. The practices of waste management differ from developed and developing nations. In fact, there is difference in methods used in the urban and rural areas, and also for industrial or residential producers. It is the responsibility of local government authorities to manage non-hazardous residential and institutional waste in metro areas. However, the management for non-hazardous commercial and industrial waste is done by the generator. There are various methods of waste disposal including integrated waste management, Plasma gasification, Landfill, Supercritical water decomposition and Incineration. There are lots of concepts about waste management which differ in their usage as per the varying regions or countries. Some of the widely used concepts include Waste hierarchy, Extended producer responsibility and Polluter pays principle. The waste hierarchy points to the reduce, reuse and recycle that classify waste management strategies as per their effectiveness in regards to waste minimization. The waste hierarchy is the cornerstone of majority of waste minimization strategies. It focuses on taking out the maximum practical advantages from products and generating least amount of waste. The Extended Producer Responsibility (EPR) is a strategy that is intended for the integration of all costs related with products across their life cycles into the market price of the product. The Polluter Pays Principle suggests that in case of waste leading to any impact on the environment, the polluting party is held responsible and it needs to pays for it. The waste management refers to the need for a waste producer to pay for proper waste disposal. Effective Techniques of waste management:- 1) LANDFILL: it is one of the inexpensive methods of waste management. In this waste is dumped on an abandoned land. Be cautious that no toxic or hazardous waste gets dumped in landfill. 2) INCINERATION: Toxic substances that cannot be dumped are burnt. This method is not much in action as this emits harmful pollutants leading to pollution. 3) COMPOSTING: Organic wastes from homes garden eg- food, plants, etc are decomposed, recycled used as manure for agriculture purpose. 4) MECHANICAL BIOLOGICALTREATMENT: Glass, plastic other recyclable waste is put into waste treatment plant. Recyclable content from waste is taken converted to calorific fuel that in turn is used by power plants. 5) PYROLYSIS GASIFICATION: Waste products are treated at high temperature7 high pressure. Its a thermal technique. In pyrolysis, waste is converted into solid liquid, in which solid is refined into carbon form liquid got from the waste is used as energy giving oil. In gasification, waste is converted into synthetic gases: that are burnt to give high energy. (6) Disposal: Non recyclable wastes are dumped into a vast abandoned land. This is called landfills. Only care should be taken that toxic waste does not enter the soil and water system. The people in charge of landfill department must supervise approve the dumping site. Care should be taken about depth allowed till dumping, the nature of the waste dumped, etc must be approved MUNICIPAL SOLID WASTE 1. Municipal Solid Waste Garbage is generally referred to Waste and is also termed as rubbish, trash, junk, unwanted or undesired material.As per the Municipal Solid Waste (Management Handling) Rule,2000 garbage is define as Municipal Solid Waste which includes commercial and residential wastes generated in a municipal or notified areas in either solid or semi-solid form excluding industrial hazardous wastes but including treated bio-medical wastes Municipal solid waste consists of household waste, construction and demolition debris, sanitation residue, and waste from streets. This garbage is generated mainly from residential and commercial complexes. 2. Main Sources of Municipal Waste House hold waste Commercials: Street sweeping Hotels and restaurants Clinics and dispensaries Construction and demolition Horticulture Sludge 3. Composition of Municipal Solid Waste in India In India, the biodegradable portion dominates the bulk of Municipal Solid Waste. Generally, the biodegradable portion is mainly due to food and yard waste With rising urbanisation and change in lifestyle and food habits, the amount of municipal solid waste has been increasing rapidly and its composition changing. There are different categories of waste generated, each takes their own time to degenerate (as illustrated in the table below). 4. Life Cycle of Municipal Solid Waste 5. Municipal Solid Waste Management Practices in India The term municipal solid waste refers to solid waste from houses, streets and public places, shops, offices, and hospitals. Management of these types of waste is most often the responsibility of Municipal or other Governmental authorities. Except in the metropolitan cities, SWM is the responsibility of a health officer who is assisted by the engineering department in the transportation work. The activity is mostly labour intensive, and 2-3 workers are provided per 1000 residents served. The municipal agencies spend 5-25% of their budget on SWM A typical waste management system in a low- or middle-income country like India includes the following elements: Waste generation and storage Segregation, reuse, and recycling at the household level Primary waste collection and transport to a transfer station or community bin Street sweeping and cleansing of public places Management of the transfer station or community bin Secondary collection and transport to the waste disposal site Waste disposal in landfills But in most of the Indian cities open dumping is the Common Practices which is adversely affecting on environment and Public health. 6. Adverse Effect of open dump An open dumping is defined as a land disposal site at which solid wastes are disposed of in a manner that does not protect the environment, are susceptible to open burning, and are exposed to the elements, vectors, and scavengers. Open dumping can include solid waste disposal facilities or practices that pose a reasonable probability of adverse effects on health or the environment. Health Effect The health risks associated with illegal dumping are significant. Areas used for open dumping may be easily accessible to people, especially children, who are vulnerable to the physical (protruding nails or sharp edges) and chemical (harmful fluids or dust) hazards posed by wastes. Rodents, insects, and other vermin attracted to open dump sites may also pose health risks. Dump sites with scrap tires provide an ideal breeding ground for mosquitoes, which can multiply 100 times faster than normal in the warm stagnant water standing in scrap tire causing several illnesses. Poisoning and chemical burns resulting from contact with small amounts of hazardous, chemical waste mixed with general waste during collection transportation. Burns and other injuries can occur resulting from occupational accidents and methane gas exposure at waste disposal sites. Environment pollution Air pollution Dust generated from on-site vehicle movements, and placement of waste and materials Water pollution Runoff from open dump sites containing chemicals may contaminate wells and surface water used as sources of drinking water open dumping can also impact proper drainage of runoff, making areas more susceptible to flooding when wastes block ravines, creeks, culverts, and drainage basins also contamination of groundwater resources and surface water from leachate emissions. Soil Contamination Permanent or temporary loss of productive land Global Warming and Climate Change In most of the cities towns, the municipal solid waste is being dumped burnt in open spaces without understanding the adverse impacts on the environment. The waste in the dumping ground undergoes various anaerobic reactions produces offensive Green House gases such as CO2, CH4 etc. These gases are contributing potentially to Global Warming Climate Change phenomenon. 7. Integrated Solid waste Management Integrated Solid Waste Management (ISWM) is a tool to determine the most energy-efficient, least-polluting ways to deal with the various components items of a communitys Solid Waste stream. The twin goals of ISWM are to: Retain as much as possible of that energy those materials in a useful state. Avoid releasing that energy or matter into the environment as a pollutant. Benefits of Integrated Solid waste management The concept of ISWM plan derives from the necessity to look at alternative sources of collection, transportation and most importantly, disposal to ensure a healthy living environment in urban cities. Local and regional economies benefit by the continued exchange value of the reclaimed materials and products and the jobs created in reprocessing and reselling them. National and global resource natural depletion is reduced, contributing to a more sustainable long-term economy. Pollution from landfills is reduced because many toxic or otherwise polluting materials are diverted from the landfills, and because the overall volume of land filled material is reduced. 8. Legal framework for Municipal Solid Waste in India Municipal Solid Waste (Managment Handling ) Rule was notified by the Ministry of Environment and Forest, Govt. of India [vide No.S.O.908 (B) dated the 25th September 2000]. The objective of these Rules was to make every municipal authority responsible for the implementation of the various provisions of the Rules within its territorial area and also to develop an effective infrastructure for collection, storage, segregation, transportation, processing and disposal of Municipal Solid Wastes. The Civic bodies have the responsibility to enforce these rules.

Moral Split and Respect Essay -- Morality Right Wrong Essays

Moral Split and Respect We will always find ourselves in â€Å"moral split† situations. We struggle to make the right decision and hoping that what we decide would be the correct choice. Sometimes our decisions are strictly depended on the notion of self-filling prophecy while others are for the sake of philanthropy. We are selfish if the chosen actions turn out to be a negative impact on the majority of people; however, the negativity is unforeseeable. If we know ahead of time that our decisions are going to be harmful to others then more likely than not we would have tried to avoid that complication. Then again, life is unpredictable. It is unpredictable just like the Vietnam War. Americans went into the war with culture relativism. They thought the decision to assist in the fighting against communism was the ultimate must. They sent young men blindly into a foreign land and were so positive that it was going to be an ideal outcome. If the Northern Vietnamese was defeated, then it might be a different story; however, the consequences they must face. On the other hand, the Vietnamese had two different perspectives of the war. The Southern Vietnamese believed that the Americans were angels sent from above to rescue them from the communists. The Northern Vietnamese thought that the Americans should mind their own business. We cannot say either views were right or wrong, rather, they were picked from the same moral standards but in different circumstances. The South, America and the North yenned for victory. They made decisions that each one truly believed to be the preeminent; therefore, no sides should be unnecessarily criticized. Similarly to us, they were making the right decisions based on personal valuations of ... ...ting will never â€Å"understand everything [and] would be incomplete forever† (249). The only understanding that these people are left with is the pondering of the possible outcome if they have chosen otherwise; not to fight. If that person truly believes that the war is the only way to solve the problem then that it would be ethically correct for him to be involved because morality is based on a person’s own judgment of what is right and wrong. On the other hand, if a person feels that is it wrong, without a doubt, then it is sad to believe that he chooses to go against his morals. Works Cited Johnson, Brendan B. â€Å"The Movie Quotes Site: The Deer Hunter.† (1997). 6 Dec. 2003 . Dirks, Tim. â€Å"Greatest Films: The Deer Hunter.† (1996). 6 Dec. 2003 â€Å"IMDb: Full Metal Jacket.† (1990). 6 Dec. 2003 â€Å"Amazon.com: Apocalypse Now Redux.† (1996). 6 Dec. 2003

Alice Walkers In Love and Trouble Essay examples -- Alice Walker Love

Alice Walker's In Love and Trouble Stories from In Love and Trouble, like other Alice Walker’s works, are the portrayal of black women. I would interpret the term â€Å"black women† as women who have gone through all sorts of hardship and struggles, but not all women in the world or only those with black skin. I strongly argue that Walker’s characters are better represented as women who suffer the way African American women do, than as women with black skin. I will justify my argument by referring to specific examples from two short stories in the book, namely Roselily and Everyday Use. The characters in In Love and Trouble are not represented by all women because not all women carry as many burdens as the characters in the book. One group of women excluded is the white. As Clenora points out African-American women suffer from â€Å"a tripartite form of oppression- racism, classism, and sexism† (192). All black women in the book have to bear the triple burden. Living in a white-dominant society, they are oppressed by the white. Their race also leads to their poverty. Being in a male-dominant society, they are abused by their husbands who are themselves abused by the white. â€Å"These women [are] simply defeated in one way or another by the external circumstances of their lives† (Washington 89-90). In Roselily, Roselily is also a victim of the triple burden. Although there is no direct description of how she is oppressed by the white, it is implied: â€Å"She can imagine God, a small black boy [my emphasis], timidly pulling the preacher’s coattail† (4). In Roseliliy’s imagination, God has black skin, which is a sharp contrast to the traditional white God image in the Western world. The black God image shows her ques... ...tudies.† Phylon 49.1 (Spring-Summer 1992): 33-41. Christian, Barbara T. Introduction. Everyday Use. By Walker Alice. New Jersey: Rutgers U, 1994. 3-17. Clenora, Hudson Weems. â€Å"The Tripartite Plight of African-American Women as Reflected in the Novels of Hurston and Walker.† Journal of Black Studies 20.2 (December 1989): 192-207. Hui, Fung-mei, Sandra. â€Å"Race and Gender in the Works of Maxine Hong Kingston, Alice Walker and Toni Morrison.† Diss. U of Hong Kong, 2004. Walker Alice. In Love and Trouble: Stories of Black Women. Florida: Harcourt, 1995. Washington, Mary Helen. â€Å"An Essay on Alice Walker.† Everyday Use. Ed. Christian, Barbara T. New Jersey: Rutgers U, 1994. 85-103. Weston, Ruth D. â€Å"Who Touches This Touches a Woman: The Naked Self in Alice Walker.† Critical Essays on Alice Walker. Ed. Dieke, Ikenna. London: Greenwood, 1999. 153-61. Alice Walker's In Love and Trouble Essay examples -- Alice Walker Love Alice Walker's In Love and Trouble Stories from In Love and Trouble, like other Alice Walker’s works, are the portrayal of black women. I would interpret the term â€Å"black women† as women who have gone through all sorts of hardship and struggles, but not all women in the world or only those with black skin. I strongly argue that Walker’s characters are better represented as women who suffer the way African American women do, than as women with black skin. I will justify my argument by referring to specific examples from two short stories in the book, namely Roselily and Everyday Use. The characters in In Love and Trouble are not represented by all women because not all women carry as many burdens as the characters in the book. One group of women excluded is the white. As Clenora points out African-American women suffer from â€Å"a tripartite form of oppression- racism, classism, and sexism† (192). All black women in the book have to bear the triple burden. Living in a white-dominant society, they are oppressed by the white. Their race also leads to their poverty. Being in a male-dominant society, they are abused by their husbands who are themselves abused by the white. â€Å"These women [are] simply defeated in one way or another by the external circumstances of their lives† (Washington 89-90). In Roselily, Roselily is also a victim of the triple burden. Although there is no direct description of how she is oppressed by the white, it is implied: â€Å"She can imagine God, a small black boy [my emphasis], timidly pulling the preacher’s coattail† (4). In Roseliliy’s imagination, God has black skin, which is a sharp contrast to the traditional white God image in the Western world. The black God image shows her ques... ...tudies.† Phylon 49.1 (Spring-Summer 1992): 33-41. Christian, Barbara T. Introduction. Everyday Use. By Walker Alice. New Jersey: Rutgers U, 1994. 3-17. Clenora, Hudson Weems. â€Å"The Tripartite Plight of African-American Women as Reflected in the Novels of Hurston and Walker.† Journal of Black Studies 20.2 (December 1989): 192-207. Hui, Fung-mei, Sandra. â€Å"Race and Gender in the Works of Maxine Hong Kingston, Alice Walker and Toni Morrison.† Diss. U of Hong Kong, 2004. Walker Alice. In Love and Trouble: Stories of Black Women. Florida: Harcourt, 1995. Washington, Mary Helen. â€Å"An Essay on Alice Walker.† Everyday Use. Ed. Christian, Barbara T. New Jersey: Rutgers U, 1994. 85-103. Weston, Ruth D. â€Å"Who Touches This Touches a Woman: The Naked Self in Alice Walker.† Critical Essays on Alice Walker. Ed. Dieke, Ikenna. London: Greenwood, 1999. 153-61.

Self-Recognition and Embarrassment :: essays research papers

Self-Recognition and Embarrassment   Ã‚  Ã‚  Ã‚  Ã‚  Our group’s task was to measure self-recognition and embarrassment in children ages 1-3. We had 3 children to work with, Arika was 9 months, Charlotte was 17 months and Lydia was 28 months old. We preformed 3 tasks on these children. The first was the â€Å"Overcompliment situation†. Secondly, we did the â€Å"Mirror situation† and last we did the â€Å"Request to dance situation†. Our findings in these situations lead us to some conclusions about self-awareness and feeling embarrassed.   Ã‚  Ã‚  Ã‚  Ã‚  The procedure we used was a fairly simple one, but it needed to be followed to get accurate results. The first task we did was the Overcompliment situation. With the hidden video camera running, we played with the children for a few minutes so they could get as used to us as they would in that short period of time. Then we proceeded to give them compliment after compliment, for example; â€Å"you are so pretty†, â€Å"good job†, â€Å"you’re doing great†. After doing this you should feel a little embarrassed yourself. This task is used to see how the child reacts to the barrage of compliments. If they keep playing as they were, make eye contact periodically, they most likely weren’t embarrassed. But if they keep their head down away from the experimenter or have a silly, self-conscious smile they probably are embarrassed. Our first Overcompliment experiment was with Charlotte. She showed no reaction to Kellie giving her numerous compliments; she just played without even looking at her. This does not necessarily mean that Charlotte had no feelings about Kellie’s compliments; in fact it probably means that she was more embarrassed than anything. When it was Lydia’s turn to go Mia and I watched her play for a few minutes, then began the onslaught of compliments. Lydia didn’t even acknowledge the fact that we were speaking to her. I think she did realize that we were saying how good she was doing and because of that she played more aggressively. She never looked at either of us, she never looked to her mother for comfort or to see why these people were saying these things to her, she just kept playing with her trains. Table 1 Age in months  Ã‚  Ã‚  Ã‚  Ã‚  Reaction 21-24  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚ ¾ of all children 20  Ã‚  Ã‚  Ã‚  Ã‚  It was common, but not expected 15-18  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚ ¼ of all children 9-12  Ã‚  Ã‚  Ã‚  Ã‚  No children reacted   Ã‚  Ã‚  Ã‚  Ã‚  The second task was the mirror situation. This experiment was first done by R. Amsterdam in 1972 on Chimpanzees.

Shell Case Study

The Case Study on â€Å"Organizational change at Royal Dutch/Shell† This case study on â€Å"Organizational Change at Royal Dutch/Shell† deals with the organizational change that the world’s largest non-state-owned oil company made to respond its operating environmental changes in 1990s (Hill, C 2005, pp. 476-477) While there are a few different structures of global organizations such as worldwide area structure, worldwide product divisional structure and global matrix structure, the Anglo-Dutch company Royal Dutch/Shell (hereinafter Shell) decided to be structured with a matrix structure from the 1950s until 1994.Under the matrix structure, the head of each operating company reported to two bosses; one boss was responsible for the geographical region or country and the other was responsible for the business activity worldwide (Shell’s business activities included oil exploration and production, oil products, chemicals, gas and coal). There were two major benefits that Shell enjoyed from this matrix structure for about 40 years. First, their decision making process was based on the consensus building between the two bosses. Because of its side effects such as slow and cumbersome process, it might be not proper for some organizations.However as the nature of Shell’s business environment is that most big decisions are long-term ones that involve huge capital expenditures and as a result they could review thoroughly all the big decisions, this decision making process was beneficial to the company. Second, this slow decision making process caused substantial decentralization by default to the heads of the individual operating companies. Thanks to this decentralization, Shell could respond to local differences in government regulations, competitive conditions and consumer tastes.Even though there were drawbacks such as slow and cumbersome process, the matrix structure fit the environment of the global oil and chemical industries in the 1980s. In the 1980s, Shell sought to grow through acquisition. It bought out the remaining 30% shareholding in Shell Oil in 1985 to consolidate its American operations. While the oil price plummeted in the winter of 1986 when the price fell from $31 per barrel to $10, Shell managed its budget by half: the company had to work much harder to develop new projects more cheaply. As a esult, Shell could make huge improvements in drilling techniques such as slim-hole drilling and directional drilling. The use of 3D seismic became widespread. (from Shell’s official homepage; 1980s to the new millennium). All of these activities worked well under the matrix structure of Shell until the end of 1980s. There was a huge environmental change in 1990. It’s the Gulf War. The Iraqi invasion of Kuwait, partly prompted by the low price of oil, led to uncertainty about production and prices spiked. Iraq wanted to gain control of the world's third largest oil producer to give it more control over the world market.Following the Gulf war to liberate Kuwait, crude oil prices entered a period of steady decline, reaching their lowest level in 1994 for 21 years (BBC, Why the oil price keeps rising, June 2008). As the oil prices declined, naturally there was pressure on Shell’s profit margins. Although it had traditionally been among the most profitable oil companies in the world, its relative performance began to slip in the early 1990s as its competitors adapted rapidly to the environment changes. As a result, this suggested that the Shell senior management team review its strategy and the fit between strategy and organizational structure.In 1995, Shell abandoned its 40 year old matrix structure and adopted divisional line structure based on its new strategy to lower the operating costs just as its competitors did. Under the new divisional line structure, Shell now operates with five global product divisions- exploration and production, oil products, chemical, gas and coal. The difference between the organization after 1995 and that before 1994 is that the power of the each global division will increase and the responsibilities of the country (or regional) chefs are reduced.The Shell’s change led to enhanced fit between operating environment, strategy and organizational architecture. As mentioned earlier, Shell's operating environment changed in the early of 1990s with continuing slack demand for oil and weak oil price which caused pressure on profit margins. In order to overcome the challenges, Shell changed its strategy to lowering operating costs by a sharp reduction in head office overhead and the elimination of unnecessary duplication of facilities across countries.This new strategy could be achieved via the change of its reorganization in 1995 from matrix organization to divisional lines structure. As a result of the change, Shell could reduce the need for a large head office bureaucracy and eliminated unnecessary duplicatio n of facilities across countries. Eventually, production may be consolidated in lager facilities that serve an entire region, rather than a single country, with which it could enjoy the greater scale economies. In summary, Shell’s organizational structure change in 1995 could contribute its business strategy changes which were driven by the operating environment changes.

Psychodynamic vs Behaviourist Theory

Psychology is not just philosophical speculation and reasoning over the years it has evolved and it is now also recognised as a science, to understand what psychology is all about it is necessary to know it’s origins and the theorist who brought it out of obscurity, Sigmund Freud. He developed the Psychodynamic or Psychoanalytical perspective to enable better understanding of human behaviour these concepts will be discussed further later in this study. After Freud opened the gateway other perspectives and approaches have been developed, now with five main areas of psychology – Cognitive, Behaviourist, Biopsychology and Humanist approaches. For a comparison with the Psychodynamic theory, Behaviourist Theory will be discussed. Psychodynamic theory is referred to in psychological literature more than any other. This is the stereotypical psychology – looking into your past, discovering hidden desires, rummaging through the unconscious. It is the most radical of the five theories, and by far the most criticised – accused of being sexist, seeing the human population as ill, and considering sex and hostility as the only motivation for human actions. However, this theory has proven to be one of the most influential forces in the twentieth century. Sigmund Freud believed that humans are driven from birth by two innate instincts Eros the life instinct – the self-preserving and erotic instinct and Thanatos the death instinct – the self destructive, aggression and cruelty instinct. These are controlled by a free floating sexual energy, the libido and is seen to be the single most important motivating force in adult life, driven from birth to enhance bodily pleasure. There is a lot more to the mind than meets the eye, much like an iceberg – only the very tip is showing. He is the one who came up with the concept of one's unconscious – the part of the mind where desires and memories are stored, unrecognised, only hinted at through dreams or slips of the tongue or the ‘Freudian slip’ as it is more widely known. Rallying between the conscious and unconscious are the id, ego, and superego – separate and conflicting forces, requiring a balance for mental health and normal behaviour. The id is a person's animal force, their need to satisfy basic psychological needs. The superego is the ‘ideal' force, the civilised, competent figure the person strives to be. The ego sort of regulates the two, keeping the id satisfied while staying within the guidelines of the superego. The strength of each individual force is a factor in personality – if a person's superego is too strong, they are seen as rigid and guilty. If a person's id is too strong, they are seen as delinquent and antisocial (Boeree, 2000). The psychodynamic theory also established the idea that what happens in a person's childhood is one of the most important factors in personality development, especially traumatic experiences. The theory states that children who go through such things repress their memories, and this is the cause of adulthood mental disease. In order to further understand how personalities are shaped during childhood, Freud thought up the psychosexual stages. This shows the development of the id and the establishment of pleasure-sensitive areas known as erogenous zones. This also brings about the idea of fixations. Such things are developed in the Oral stage of a child’s development from birth to eighteen months where the mouth is the source of nourishment and pleasure an example of this is seen in a nursing infant and if deprived of nourishment will fixate their pleasure seeking energies on this stage, the need to constantly stimulate the mouth through smoking, biting and chewing. The next is the Anal stage between eighteen and thirty-six months focus on bladder and bowl elimination and is seen as a source of pleasure when the child is able to control them, this is why toilet training usually happens around this age and if not mastered an adult would be seen to be anal expulsive or anal retentive. Phallic stage between age three and five years where sexual energy is focused on the genitals. Oedipus and Electra complex in which the child unconsciously wishes to posses the parent of the opposite sex and rid themselves of the parent of the same sex. The result of this desire in boys would experience castration anxiety which would drive them to identify with their fathers. If there is no male figure in this stage of a child’s development it is thought that the child will have problems with authority figures later in life as he has never had the chance to conclude this stage. Freud’s explanation for the female development claiming that they would experience penis envy (a realisation they do not have a penis) they would eventually overcome by achieving motherhood and having their own baby. Latency stage from six years through puberty here the child will develop their confidence and mastery of the world around them. He believed that during this stage their experiences and excitations of previous stages are repressed and children develop infantile amnesia being unable to remember much of their earlier years. The Genital stage from twelve years upwards to adulthood is the culmination of the psychosexual development and the fixing of sexual energy in the genitals. This eventually directs humans towards sexual intercourse and the beginnings of the next cycle of life (Breger, 2009). John Watson a theorist who rejected the idea of introspection and every part of the psychodynamic theory, suggested the Behaviourist view is an objective, experimental branch of natural science who are interested in prediction and control of behaviour, most of the early research was carried out on animals before moving onto humans. This is an approach that believes people are born ‘Tabula rasa’ literally meaning ‘blank slate’, that all human behaviour is infinitely plastic and therefore is ultimately explainable in terms of the experiences that an organism goes through rather than any genetic predisposition of characteristics that the organism possesses. The relationship between the environment and the organism is seen as a straight line, in that the organisms act on their environment, which in turn provides rewards and punishments to determine the future probability of a response occurring. Behaviours are acquired or learned in one of two main ways, these are classical conditioning and operant conditioning. Examples of classical conditioning applied to real life are things like, taste aversion, learned emotions, advertising and development of phobias. Use of operant conditioning is referred to as behaviour modification such as in a classroom or therapy settings (Wyman, 2005). Watson suggests that children have three basic emotions, fear, rage and love and attempted to prove that these emotions could be artificially conditioned. The experiment of Little Albert is his most famous and controversial experiment, Watson and a graduate assistant named Rosalie Rayner conditioned a small child to fear a white rat. They accomplished this by repeatedly pairing the white rat with a loud, frightening clanging noise. They were also able to demonstrate that this fear could be generalized to other white, furry objects. The ethics of the experiment are often criticized today, especially because the child's fear was never deconditioned. Another example of classical conditionning is Ian Pavlov ‘Dogs’, in this experiment he noted that dogs would salivate before the delivery of food. In a series of well-known experiments, he presented a variety of stimuli before the presentation of food, eventually finding that, after repeated association, a dog would salivate (response) to the presence of a stimulus (noise) other than food (Bitterman, 2006). The most influential of all behaviourists is B F Skinner he is famous for his research on operant conditioning and negative reinforcement. He developed a device called the ‘cumulative recorder’ which showed rates of responding as a sloped line. Using this device, he found that behaviour did not depend on the preceding stimulus as Watson and Pavlov maintained. Instead, Skinner found that behaviours were dependent upon what happens after the response, therefore, using positive and negative reinforcement responses can be conditioned to a stimulus, those that are rewarded will increase and those that are not will decrease (Rubin, 2003). Not unlike other perspectives Behaviourism has gone through many transformations in the years since is conception by John Watson, one of the recent extensions in this approach has been the development of Social Learning theory. This theory is most relevant to criminology. Bandura suggests that we learn through observation, imitation and modelling of a significant other, people learn through the outcome of those behaviours and later a person will form an idea which serves as a guide for action. A significant other could be someone one aspires to become, not necessarily family, it could be someone famous for instance. If a person sees another being rewarded or punished for a certain behaviour they may or may not copy that behaviour, what is seen as a punishment or reward for one person may not be for another. However, if it is a person they aspire to be children in particular tend to emulate this behaviour either good or bad. Part of this study was the ‘Bobo doll’ experiment, he demonstrated that children learn and imitate behaviours they have observed in other people. The children observed an adult acting violently toward a Bobo doll. When the children were later allowed to play in a room with the Bobo doll, they began to imitate the aggressive actions they had previously observed (Green, 2003). Psychology has changed its face over the many years since Freud first introduced the psychodynamic theory putting forward a different way of trying to understand why people behave the way they do, moving onto the Behaviourist approach which completely refutes Freud’s theory by refusing to accept that people are born with natural innate instincts and that consciousness is the subject matter of psychology, who believe that psychology is about behaviour and activities and that the consciousness is not definable. They leave a huge gaping whole in their theory relating to perception, sensations, memories and imagination. Whereas Freud simply focused on his masculinity and the inferiority of the female population, although he can be forgiven for this as his theory came about in the Victorian era and this theory was a major breakthrough in history and is still one of the biggest thinkers and without whom psychologists and the like would not know as much about ourselves as people do. References Breger, L. (2009). From Instinct to Identity: The Development of Personality. 1st ed. New Jersey: Transaction Publishers. 1-18. Grieve, K. (2006). A student's A-Z of Psychology. 1st ed. California: Juta Academic. Hayes, N. (1993). A first course in Psychology. 12th ed. Cheltenham: Thomas Nelson and Sons Ltd. Bitterman, M. (2006). Classical Conditioning since Pavlov. Review of General Psychology. 10 (4), 365-375. Wyman, R. (2005). Experimental anaylasis of nature-nurture interactions. JEZ. 03A (6), 415-421. Boeree, G. (2000). Freud and Psychoanalysis. Available: http://webspace. ship. edu/cgboer/psychoanalysis. html#Johann_Reil. Last accessed 10 November 2010 Geen, C. (2003). Transmission of aggression through immitation of aggressive models. Available: http://psychclassics. asu. edu/Bandura/bobo. htm. Last accessed 10 Nov 2010. Rubin, J. (2003). From Pavlov to Skinner Box. Available: http://www. juliantrubin. com/bigten/skinnerbox. html. Last accessed 10 November 2010