Desert Economy Struggling To Stay Afloat Essay Example for Free

Desert Economy Struggling To Stay Afloat EssayWhen the Statess economy fell into a break in 2008, it took down mexico along with it. America is by far the largest buyer of Mexican products, last year alone doing $400 billion in business. The Economist article, do The Desert Bloom, brings to light the condition that Mexicos economy is currently in, restricted by cartels, monopolies and its unfortunate situation with America.When stocks plummeted and jobs were lost in america, Mexicos economy as a substantial fell by 6.1%, the northern state of Coahuila getting hit the worst with a drop of 12. 3%. Until the recession, Mexico was on schedule to have a credible decade but with personal income growth now at only 0.6% , some of the worst in the world, it doesnt look promising. Mexicos unemployment rate peaked at 6.4% in 2009 and is only slowly getting better.The foundation of Mexicos economy is based on its exports. With americans share of Mexicos exports falling from 89% to 78% an d expecting to get worse, mexico has a problem on their hands. At the beginning of the decade, Mexico claimed the largest Latin American economy but since has been over taken by brazil with a GDP grow to more so 2 times that of Mexicos. In 2010, the murder rate was 17 proscribed of every 100,000 people, expected to cause a 1% drop in Mexicos annual growth rate. Foreign direct investment has fall from $30 billion to just half that over the last 5 years. With so many problems pass Mexicos potential, the country needs to get everything in order to to revive itself from the current recession.Mexico has been hit by the steepest recession of any latin american country. A recession can be explained by a significant decline in activity across the economy effecting in industrial production, employment, income and trade. Between 2008 and 2009, 700,000 jobs were lost in Mexico. In certain parts, 4 in 10 business shut down.The head of economic planning in Mexicos fiancee ministry, Miguel Me ssmacher, has seen a major breakage in the direction of exports out of his country. Sales to latin America and asia are growing twice as fast as those to America. Mexicos largest export is the automotive industry, although its exports to America make up only 65%.Eduardo soils head of the industrys national association thinks this is a good sign because it always Mexico to establish markets in other countries, theory up more opportunities. His goal is to get it down to 50%. Others argue that Mexico can not become a commodity exporter. just because countries like chinaware have a demand for soy beans, doesnt mean that Mexico should start growing and export this product. They believe the economic future still lies in Americas economy. They way out of the recession is to gain a bigger piece of Americas slowly growing economy.

Principles and Practises for International Management Essay Example for Free

Principles and Practises for International Management EssayTo achieve the new worldwide revenue enhancement objectives I will have to convince the senior management to increase the establishforce in my department to share my responsibilities, as they are non integrity persons cup of tea. I will have to ensure that this workforce consists of serious individuals who are capable of working towards the achievement of a exclusive goal with common mindset. I will have to make sure that local people are hired in the countrys global units, as they would prove to be helpful in making the company adapt to the culture of the foreign countries. Along with them and the few employees in the company who were not born in this country, I will try to identify with the countries in which our company has spread its operations. This can be done by in knowledge analysis of the countries political, sociological, demographic and geographic features. I will also have to be well prepared to communi cate effectively across different cultural barriers and languages. I would urge the senior management to master skills to effectively manage cultural diversity in workforce.It has been rightly pointed by Rue and Byars that Achieving success in international business demands that a firms human resource practices be adapted to country norms. (1992, p. 130) The company would also have to thoroughly pack the international market and design its marketing strategy accordingly. In no way should the company disrespect the local culture in which it is operating. Instead, it should try to merge the local culture with its corporate identity and be always consistent in this.Guidelines for the company staff should be designed in such a way that there is no scope of inconsistency or confusion across borders. The employees should be trained, keeping in mind the trends set by the flourishing multinational companies. They should be encouraged to perform their best. The international business uni ts should be given similar autonomy as the local units, both in crisis emplacement and at decision-making times.In the words of Leandri hold local operations accountable to the corporate office yet give them enough autonomy to make obligatory decisions. (2000, para. 9) By making the company adapt to the demands of international expansion and by developing my own communication skills and potential of working in diverse work environments, it will not be hard to gain the payoffs that international business offers.

Engine Cooling And Lubrication System

Engine Cooling And Lubrication SystemCooling System Despite the vast proceeds in the basic internal burning locomotive engines, around 70% of the animation from the gasoline is converted to soup up. As it is non dissipated to the atmosphere on its own, a chilling organization is employed for this propose.Several purposes of the cooling system which it serves by cooling the engine include cooling the engine to keep it from everywhereheating by rapturering the heat to the contrast. This helps avoid the excessive wear and tear at t both temperatures, auto-ignition due to hot cylinder which may burden in knocking and hence, piston/cylinder failure. It may also incorporate thermal stresses which is non good for the engine itself.Figure . Cooling system and plumbing connectionWhile it serves the purpose of cooling the engine, it also helps the engine to warm up quickly during cold start ups and past chief(prenominal)taining a constant temperature. When the engine is cold, components wear out scurrying besides and the engine is slight efficient, emitting to a greater extent than pollution.Types of Cooling SystemThere argon two types of cooling systems found in carsAir-cooledLiquid-CooledAir-Cooled Engines whatsoever sm alone and the medium-sized engines argon cinch-cooled. This category includes most small engines like lawn mowers, chain saws, model airplanes etc. Using the air-cooled system furnishs both the weight and expenditure of the engine to be kept low, along with reduced complexity of the machine.The air-cooled system is still widely social functiond on most of the motor bicycles in substance abuse these days. This system utilizes the concept of heat transfer through fins to cool the engine. The cross-sectional ara of the fin being larger closer to the head and a diminution in the ara as we move further from the engine block.The basic principle on which the air-cooled engines rely on is the flow of air crosswise their external s urfaces to remove the excess heat to keep the engine from overheating. The airflow on machines like motorcycles and aircrafts is provided across the surface when the vehicle moves forward. Deflectors and ductwork is incorporated to direct the airflow to the critical locations where more cooling is required. The outer surface of the engine is made from a good conductor of heat and the surface is finned to promote maximum heat transfer, along with which an extra fan is utilise to increase the air-flow rate whereas others use the concept of free-convection. These fins atomic number 18 to be properly designed for appropriate cooling notion which is required.Some simple machine engines also use exposed flywheels with air-deflectors fastened to the surface. When the engine is in ope dimensionn, these deflectors create air motion which increases the heat transfer on the finned surface. rase after considering and applying all the measures, the uniform cooling of cylinders is still diff icult to achieve on air-cooled engines as compared to the liquid-cooled engines. The figure below shows that the cooling needs are not the same at all the locations.Figure . Variation of heat losses from the fins of an air-cooled aircraft engine. Seventy-one percent of the heat losses occur on the hotter side of the cylinder, containing the exhaust valve. The engine shown was used on a number of different aircrafts.Hotter areas, such as the ones around the exhaust valve and manifold need greater cooling and hence larger finned surface area. Cooling the front of an air-cooled engine which faces the forward motion of the vehicle is often easier and efficient as compared to the back down surface of the engine. This may result in temperature differences and thermal expansion hassles.DisadvantagesDisadvantages of air-cooled engines are that theyAre less efficient,Are noisier, with greater air flow requirements and no water jacket to dampen the noise,Need a directed air flow and finned surfaces.AdvantagesWhen compared with liquid-cooled engines, air-cooled engines engage the following advantagesThey are lighter in weight,They live less,No coolant system failures (e.g., water pump, hoses),No engine freeze-ups, andFaster engine warmup.Liquid-Cooled EnginesIn a liquid or water-cooled engine, the engine block is border by a water jacket through which the coolant flows. This allows for a better control of the heat removal from the engine, just by added weight and a more complex system.Very few water-cooled engines use just water as the cooling fluid in the water jackets this is because the water has a frost temperature of 0C which is unacceptable as coolant in colder regions, so additives are usually used for better military operation. Although water has very good heat transfer properties, besides when used alone, it causes rust and corrosion in many of the pipes of the cooling system.Ethylene glycol (C2H6O2) is the antifreeze agent which acts as a rust inhibito r and a lubricating substance for the water pump. When added to water, it lowers the freezing temperature and raises the b rock rock anointing temperature of the coolant. The properties of the mixture depend on the ratio in which water and the antifreeze agent are mixed. Pure ethylene glycol should not be used, and even at high concentrations the heat transfer properties of the water are lost as well. The properties of the ethylene glycol water mixture are shown in the table below.In addition to good thermal properties, a coolant should satisfy the following requirements1. Chemically stable under conditions of use2. Non-foaming3. Non-corrosive4. commencement perniciousness5. Non-flammable6. Low costMost commercial antifreezes satisfy these requirements. Many of them are basically ethylene glycol with small amounts of additives. Some commercial engine coolants use propylene glycol as the base ingredient. It is argued that when coolant systems leak or when the coolant experience s aged and is discarded, these products are less harmful to the environment than ethylene glycol.Basic ComponentsThe basic components of a liquid-cooled system is shown below.Figure . Basic liquid-cooled systemradiatorradiator roundabout hoseradiator bottom hosewater pumpthermostatthermostat hovictimizationelectric cooling fanthermo-time switchRadiatorThe radiator is the part of the cooling system which is responsible for the heat rejection from the coolant and into the atmosphere. The radiator core is usually made up of flattened tubes with aluminum strips (fins) that zigzag mingled with the tubes. These fins effectively transfer the heat contained in the coolant into the air stream to be lost into the atmosphere. On each end of the radiator is a tank made up of waxy to cover the ends. The tubes either run horizontally or vertically amidst the two tanks. The aluminum-plastic system is more efficient and cost effective.On radiators with plastic end caps, in that location are ga skets between the aluminum core and the plastic tanks to seal the system and keep the fluid from leaking out. The tanks fork up a large hose connection, one mounted towards the top of the radiator to let the coolant in, the other mounted at the bottom of the radiator on the other tank to let the coolant back out. On the top of the radiator is an additional opening that is capped glowering by the radiator cap.Another component in the radiator for vehicles with an automatic transmission is a offend tank mounted inside(a) one of the tanks. Fittings connect this inner tank through steel tubes to the automatic transmission. Transmission fluid is piped through this tank inside a tank to be cooled by the coolant flowing old it forrader returning to the transmission.Radiator FansOne or two electric fans are mounted on the back of the radiator close to the engine. These fans used the concept of forced convection to cool the heated coolant going through the pipes in the radiator core.If noticed, this fan starts working once the engine reaches a predefined temperature, after which the cooling by just natural convection during the forward motion of the car good dealnot be achieved. In the cars with air conditioning, there is an additional radiator mounted in front of the normal radiator. This radiator is called the air conditioner condenser, which also needs to be cooled by the air flow entering the engine compartment. As long as the air conditioning is turned on, the system will keep the fan running, even if the engine is not running hot. This is because if there is no air flow through the air conditioning condenser, the air conditioner will not be able to cool the air entering the interior.Pressure cap reserve tankThe public press cap is simply a cap which maintains the pressure in the cooling system up to a certain point. If the pressure builds up higher than the set pressure point, the spring riled valve releases the pressure.Figure . Pressure capWhen the p ressure in the cooling system reaches the point when the cap needs to release this excess pressure, some amount of coolant is bled off. The coolant which is bled off goes into the reserve tank which is not pressurized, which causes a partial vacuum in the cooling system.The radiator cap on these closed systems has a secondary valve which allows the vacuum in the cooling system to draw the coolant back from the reserve tank into the radiator.Coolant PumpIt is a simple pump which helps in circulation of the coolant around the system. This pump is run using one of the followingA fan belt that will also be responsible for driveway an additional component like an alternator or supply steering pumpA serpentine belt, which also drives the alternator, power steering pump and AC compressor among other things.The timing belt that is also responsible for driving one or more camshafts.The impeller of the pump uses centrifugal force to draw the coolant in from the lower radiator hose and send it under pressure to the engine block. A gasket seals the water pump to the engine block and prevents the flowing coolant from leaking out where the pump is attached to the block.ThermostatThe thermostat is simply a valve that measures the temperature of the coolant, and if the coolant is hot enough it opens to allow the coolant to flow through the radiator otherwise the flow to the radiator is blocked and the fluid is directed to a bypass system that returns the coolant to the engine.Figure . ThermostatThe engine is at measure allowed to run at higher temperatures of 190-195C this reduces emissions, moisture condensation inside the engine is quickly burned off improving engine life, and a more complete combustion improving enkindle economy.Oil as a CoolantThe embrocate when used to lubricate the engine also helps to cool the engine. The piston for utilization gets very little cooling from the coolant in the water jacket or the externally finned surface, so when the back surface of the piston crown is subjected to the anoint color squeeze or flow the piston is cooled to some extent. This is very necessary as the piston is one of the hottest elements in the engine. Usually, the anele is sprayed in pressurized systems, and splashed in non-pressurized systems. The crude inunct acts as the coolant on the back face of the piston crown as it absorbs energy and then runs back into the larger reservoir where it mixes with the cooler anoint and dissipates this energy into the other engine parts. This splash cooling of the piston is extremely important in small air-cooled engines as well as in go engines.A few other engine components other than the piston are also cooled by inunct circulation, either by splash or by the pressurized flow from the inunct pump. Oil enactments through internal components like the camshaft and connecting rods offer the only major cooling these parts are subjected to. As the cover cools the versatile components, it absorbs en ergy and its temperature rises. This energy is then dissipated to the rest of the engine by circulation and eventually gets absorbed in the engine coolant flow. Some high-performance engines have an petroleum cooler in their lubri burn downt circulation system. The energy absorbed by the oil as it cools the engine components is dissipated in the oil cooler, which is a heat ex interchanger cooled by either engine coolant flow or external air flow.Oil Pump The gear-type oil pump has a pair of meshing gears. The spaces between the teeth are filled with oil when the gears unmesh. The oil pump obtains oil from the oil pan and sends oil through the oil drip to the oil galleries and main bearings. Some oil passes from the old salts in the crankshaft to the rod bearings. Main bearings and rod bearings are lubricated adequately to achieve their desired objectives. In the rotor type oil pump, the inner rotor is driven and drives the outer rotor. As the rotor revolves, the gaps between the lobes are filled with oil. When the lobes of the inner rotor move into the gaps in the outer rotor, oil is forced out through the outlet of pump. An oil pump buns also be driven by a camshaft gear that drives the ignition distributor or by the crankshaft.Oil Pan Oil also flows to the cylinder head through drilled passages that make up the oil gallery, lubricates camshaft bearings and valves, and then returns to oil pan. Some engines have grooves or holes in connecting rods, which provide extra lubrication to pistons and walls of cylinders.Oil Cooler Oil cooler prevents overheating of oil, by flow of engine coolant past tubes carrying hot oil. The coolant picks excess heat and carries it to the radiator.Oil Filter The oil from oil pump flows through oil filter before reaching the engine bearings. The oil filter retains the dirt particles and allows only clean filtered oil to pass.The Lubrication system and its typesThere are three basic types of oil distribution systems used in en ginesSplash,Pressurized, orA combination of these.The crankcase is used as the oil cesspool (reservoir) in a splash system, and the crankshaft rotating at high speed in the oil distributes it to the miscellaneous moving parts by splash no oil pump is used. both components, including the valve train and camshaft, moldiness be open to the crankcase. Oil is splashed into the cylinders substructure the pistons and onto the back of the piston crowns, acting both as a lubricant and a coolant. Many small four-stroke cycle engines (lawn mowers, golf carts, etc.) use splash distribution of oil.An engine with a pressurized oil distribution system uses an oil pump to supply lubrication to the moving parts through passages built into the components. A typical automobile engine has oil passages built into the connecting rods, valve stems, push rods, rocker arms, valve seats, engine block, and many other moving components. These make up a circulation network through which oil is distributed b y the oil pump. In addition, oil is sprayed under pressure onto the cylinder walls and onto the back of the piston crowns. Most automobiles actually use dual distribution systems, relying on splash within the crankcase in addition to the pressurized flow from the oil pump. Most large stationary engines also use this kind of dual system. Most aircraft engines and a few automobile engines use a total pressurized system with the oil reservoir located separate from the crankcase. These are often called dry sump systems (i.e., the crankcase sump is dry of excess oil). Aircraft do not always fly level, and uncontrolled oil in the crankcase may not supply proper lubrication or oil pump input when the plane banks or turns. A diaphragm controls the oil level in the reservoir of a dry sump system, assuring a continuous flow into the oil pump and throughout the engine.Figure . Lubrication of an engine consisting of a combination of a pressurized system and splash systemOil pumps can be electri c or mechanically driven off the engine. Pressure at the pump exit is typically about 300 to 400 kPa. If an oil pump is driven directly off the engine, some means should be built into the system to keep the exit pressure and flow rate from fitting excessive at high engine speeds.A time of excess wear is at engine startup before the oil pump can distribute proper lubrication. It takes a few engine cycles before the flow of oil is fully established, and during this time, many parts are not properly lubricated. Adding to the problem is the fact that often the oil is cold at engine startup. Cold oil has much higher viscosity, which further delays proper circulation. A few engines have oil preheaters which electrically heat the oil before startup. Some engines have pre-oilers that heat and circulate the oil before engine startup. An electric pump lubricates all components by distributing oil throughout the engine.It is recommended that turbocharged engines be allowed to idle for a few s econds before they are turned off. This is because of the very high speeds at which the turbocharger operates. When the engine is turned off, oil circulation gunpoints and lubricated surfaces begin to lose oil. Stopping the oil supply to a turbocharger operating at high speed invites poor lubrication and high wear. To minimize this problem, the engine and turbocharger should be allowed to return to low speed (idle) before the lubrication supply is stopped.Lubrication system in 2-stroke enginesMany small engines and some experimental two-stroke cycle automobile engines use the crankcase as a compressor for the door air. Automobile engines which do this generally have the crankcase divided into several compartments, with each cylinder having its own separate compressor. These engines cannot use the crankcase as an oil sump, and an alternate method must be used to lubricate the crankshaft and other components in the crankcase. In these engines, oil is carried into the engine with th e inlet air in much the same way as the give the sack. When the fuel is added to the inlet air, usually with a carburetor, oil particles as well as fuel particles are distributed into the flow. The air flow then enters the crankcase, where it is compressed. Oil particles carried with the air lubricate the surfaces they come in contact with, first in the crankcase and then in the use of goods and services runner and cylinder.In some systems (model airplane engines, marine outboard motors, etc.), the oil is premixed with the fuel in the fuel tank. In other engines (automobiles, some golf carts, etc.), there is a separate oil reservoir that feeds a metered flow of oil into the fuel supply line or directly into the inlet air flow. Fuel-to-oil ratio extends from 301 to 4001, depending on the engine. Some modern high-performance engines have controls which regulate the fuel-oil ratio, depending on engine speed and load. Under conditions of high oil input, oil sometimes condenses in th e crankcase. Up to 30% of the oil is recirculated from the crankcase in some automobile engines. It is desirable to get at least 3000 miles per liter of oil used. Most small lower cost engines have a single average oil input setting. If too much oil is supplied, deposits form on the combustion chamber walls and valves will stick (if there are valves). If too little oil is supplied, excess wear will occur and the piston can freeze in the cylinder.Engines that add oil to the inlet fuel obviously are designed to use up oil during operation. This oil also renders to HC emissions in the exhaust due to valve overlap and poor combustion of the oil vapor in the cylinders. New oils that also burn better as fuel are being developed for two-stroke cycle engines. Some two-stroke cycle automobile engines and other medium- and large-size engines use an external supercharger to compress inlet air. These engines use pressurized/ splash lubrication systems similar to those on four-stroke cycle engi nes with the crankcase also serving as the oil sump.Lubricating OilThe oil used in an engine must serve as a lubricant, a coolant, and a vehicle for removing impurities. It must be able to withstand high temperatures without breaking down and must have a long working life. The knowledge trend in engines is toward higher operating temperatures, higher speeds, closer tolerances, and smaller oil sump capacity. All of these require improved oils compared to those used just a few years ago. Certainly, the technology of the oil industry has to continue to improve along with the technology growth of engines and fuel. Early engines and other mechanical systems were often designed to use up the lubricating oil as it was used, requiring a continuous input of fresh oil. The used oil was either burned up in the combustion chamber or allowed to fall to the ground. Just a couple of decades back, the tolerances between pistons and cylinder walls was such that engines burned some oil that seeped p ast the pistons from the crankcase. This required a periodic need to add oil and a frequent oil change due to blowby contamination of the remaining oil. HC levels in the exhaust were high because of the oil in the combustion chamber.Modern engines run hotter, have closer tolerances which keep oil consumption down, and have smaller oil sumps due to space termations. They drive more power with smaller engines by running faster and with higher compression ratios. This means higher forces and a greater need for good lubrication. At the same time, many manufacturers now suggest changing the oil every 6000 miles. Not only must the oil last longer under much more severe conditions, but new oil is not added between oil changes. Engines of the past that consumed some oil required periodic makeup oil to be added. This makeup oil mixed with the remaining used oil and improved the overall lubrication properties within the engine.The oils in modern engines must operate over an extreme temperat ure range. They must lubricate properly from the starting temperature of a cold engine to beyond the extreme steady-state temperatures that occur within the engine cylinders. They must not oxidize on the combustion chamber walls or at other hot spots such as the center crown of the piston or at the top piston ring. Oil should adhere to surfaces so that they always lubricate and provide a protective covering once against corrosion. This is often called oiliness. Oil should have high film strength to assure no metal-to-metal contact even under extreme loads. Oils should be non-toxic and non-explosive.Some desired qualities of Lubrication oilLubricating oil must satisfy the following needsLubrication. It must reduce friction and wear within the engine. It improves efficiency by reducing the friction forces between moving parts.Coolantremotion of contaminantsEnhancement of ring seal and reduction of blowbySlow corrosionStability over a large temperature rangeLong life spanLow costHydro carbon Components in Lubricating oilThe basic ingredients in most lubricating oils are hydrocarbon components made from crude oil. These are larger molecular weight species obtained from the distillation process.Additives versatile other components are added to create a lubricant that will allow for the maximum performance and life span of the engine. These additives includeAntifoam agentsThese reduce the foaming that would result when the crankshaft and other components rotate at high speed in the crankcase oil sump.Oxidation inhibitorsOxygen is trapped in the oil when foaming occurs, and this leads to possible oxidation of engine components. One such additive is zinc dithiophosphatePour-point depressantAntirust agentsDetergentsThese are made from organic salts and metallic salts. They help keep deposits and impurities in suspension and stop reactions that form varnish and other surface deposits. They help neutralize acid formed from sulfur in the fuel.Anti-wear agentsFriction redu cersViscosity index improversRating of Lubricating Oils and gradesLubricating oils are generally rated using a viscosity scale established by the Society of Automotive Engineering (SAE).The higher the viscosity value, the greater is the force call for to move adjacent surfaces or to pump oil through a passage. Viscosity is highly dependent on temperature, increasing with decreasing temperature. In the temperature range of engine operation, the dynamic viscosity of the oil can change by more than an order of magnitude. Oil viscosity also changes with shear, decreasing with increasing shear. overcharge rates within an engine range from very low values to extremely high values in the bearings and between piston and cylinder walls. The change of viscosity over these extremes can be several orders of magnitude. Common viscosity grades used in engines areSAE 5SAE 10SAE 20SAE 30SAE 40SAE 45SAE 50Common oils available includeSAE 5W-20 SAE 10W-40SAE 5W-30 SAE 10W-50SAE 5W-40 SAE 15W-40SAE 5W-50 SAE 15W-50SAE 10W-30 SAE 20W-50Synthetic OilsA number of synthetically made oils are available that give better performance than those made from crude oil. They are better at reducing friction and engine wear, have good detergency properties which keep the engine cleaner, offer less guard for moving parts, and require less pumping power for distribution. With good thermal properties, they provide better engine cooling and less variation in viscosity. Because of this, they contribute to better cold-weather starting and can reduce fuel consumption by as much as 15%. These oils cost several times as much as those made from crude oil. However, they can be used longer in an engine, with 24,000 km (15,000 miles) being the oil change period suggested by most manufacturers.Available on the market are various oil additives and special oils that can be added in small quantities to standard oils in the engine. These claim, with some justification, to improve the viscous and wear resista nce properties of normal oils. One major improvement that some of them provide is that they stick to metal surfaces and do not debilitate off when the engine is stopped, as most standard oils do. The surfaces are thus lubricated immediately when the engine is next started. With standard oils it takes several engine rotations before proper lubrication occurs, a major source of wear.Oil filtersIncluded in most pressurized oil systems is a filtration system to remove impurities from the engine oil. One of the duties of engine oil is to clean the engine by carrying contaminant impurities in suspension as it circulates. As the oil passes through filters that are part of the flow passage system these impurities are removed, cleaning the oil and allowing it to be used for a greater length of time. Contaminants get into an engine in the incoming air or fuel or can be generated within the combustion chamber when other than ideal stoichiometric combustion occurs. Dust and other impurities ar e carried by the incoming air. Some, but not all, of these are removed by an air filter.Fuels have trace amounts of impurities like sulfur, which create contaminants during the combustion process. Even pure fuel components form some contaminants, like solid carbon in some engines under some conditions. Many engine impurities are carried away with the engine exhaust, but some get into the interior of the engine, mainly in the blowby process. During blowby, fuel, air, and combustion products are forced past the pistons into the crankcase, where they mix with the engine oil. Some of the water vapor in the exhaust products condenses in the crankcase, and the resulting liquid water adds to the contaminants. The gases of blowby pass through the crankcase and are routed back into the air intake. Ideally, most of the contaminants are trapped in the oil, which then contains dust, carbon, fuel particles, sulfur, water droplets, and many other impurities. If these were not filtered out of the oil, they would be spread throughout the engine by the oil distribution system. Also, the oil would quickly become dirty and lose its lubricating properties, resulting in greater engine wear.Figure . Oil FilterFlow passages in a filter are not all the same size but usually exist in a normal bell-shaped size distribution. This means that most larger particles will be filtered out as the oil passes through the filter, but a few as large as the largest passages will get through. The choice of filter cerebrate size is a compromise. Better filtration will be obtained with smaller filter pores, but this requires a much greater flow pressure to push the oil through the filter. This also results in the filter becoming clogged quicker and requiring earlier filter cartridge change. Some filter materials and/or material of too small a pore size can even remove some additives from the oil. Filters are made from cotton, paper, cellulose, and a number of different synthetic materials. Filters ar e usually located just downstream from the oil pump exit. As a filter is used, it slowly becomes saturated with trapped impurities. As these impurities fill the filter pores, a greater pressure differential is needed to keep the same flow rate. When this needed pressure differential gets too high, the oil pump limit is reached and oil flow through the engine is slowed. The filter cartridge should be replaced before this happens.Figure . Exploded view of an Oil FilterFigure . digest size distribution for common filtersSometimes, when the pressure differential across a filter gets high enough, the cartridge structure will collapse and a hole will develop through the cartridge wall. Most of the oil pumped through the filter will then follow the path of least resistance and flow through the hole. This short circuit will reduce the pressure drop across the filter, but the oil does not get filtered.There are several ways in which the oil circulation system can be filtered1. Full-flow oil filtration. All oil flows through the filter. The filter pore size must be fairly large to avoid extreme pressures in the resulting large flow rate. This results in some larger impurities in the oil.2. Bypass oil filtration. precisely part of the oil leaving the pump flows through the filter, the rest bypassing it without being filtered. This system allows the use of a much finer filter, but only a percentage of the oil gets filtered during each circulation loop.3. Combination. Some systems use a combination of full-flow and bypass. All the oil first flows through a filter with large pores and then some of it flows through a second filter with small pores.4. Shunt filtration. This is a system using a full-flow filter and a bypass valve. All oil at first flows through the filter. As the filter cartridge dirties with age, the pressure differential across it needed to keep the oil flowing increases. When this pressure differential gets above a predetermined value, the bypass valve op ens and the oil flows around the filter. The filter cartridge must then be replaced before filtering will again occur.Solid lubricants, such as powd

Forms of Political Violence

Forms of Political ViolenceNihad SafarliPolitical violence conversions and terrorismPolitical violence has become a part of a daily life history of each person living on the Earth. Almost everyone- politicians, mass media, scientists, taxi drivers.and etc. is talking almost this. In this paper I will disassemble the reasons of its popularity by investigating its origins and the factors which trigger off semi policy-making violence. Based on the theoretical framework created by the knowledge Ive amassed before, of importly my paper is centre on two prevailing forms of policy-making violence with what this term often is being associated transmutations and terrorism. I will try to find out more preciously definition of revolutions and clarify which historical events fag be conceptualized as a revolution, also try to ascertain the main cause of terrorism.Theda Skocpols article France, Russia, mainland China A Structural Analysis of Social Revolution provided quite good defin ition of revolution , although in my opinion her study is so tightly squeezed that doesnt fit to all cases in the history. I want to criticize Skocpols conceptualization of affectionate revolutions .After reviewing the definitions given by S.Huntington and Lenin she combined the content of them and applied it for summary of revolutions in particular states. According to the author, revolution is a very quick and fundamental transformation of social conditions and class body structures and send word be achieved through develop of the lower class. The main difference of social revolutions from other forms of conflicts and transforming processes is that they attended by class insurrection, political and social transformations in social structure. But even rebellions with the selfsame(prenominal) characteristics gougenot be considered as revolutions as they dont aim to make structural changes.Skocpol used a comparative historical method, in order to give way cautiously the histo ry of some modern revolutions, use the data gathered from the cases to make generalizations. Limitation of this method is that it is good to compare only similar cases. For example, coincidence of Russian and German revolutions could be appropriate as a lot of common factors had an impact on revolutions, such as forfeit of contend. But for France war ended up with a victory and overall situation was different from Russia which makes difficult to compare French and Russian revolutions applying comparative method. Scokpol thought that trouble Russia matt-up during World War I caused the revolution as its economy couldnt respond to such huge pressure yielded by military expenditure. But the main thing is not how a boxer was punched, the main thing is how he will he be able to stand this Not only fast industrialization but also lack of capacity to respond to this rapid process, played an essential role.The challenging part of this definition is about the phrase- very rapid. The blur red part about social revolution word is due to vague starting point and the end. For instance, the Russian revolution did it begin exactly in 1917? Or may be seeds of revolutions were spread before? For defining the paradigm of rapid change, we should know whether that revolution ended exactly in October 1917 or not? Main missing point here is that we dont know during which period should structural transformation happen to be called revolution. Probably I elicit conclude that periods called revolutions, transformation happened much more rapid now carried the qualitative character.If we accept social revolutionas a fundamental transformation of hostel, we should define what is fundamental about it. The author mentioned it dimly changes in the social structure, accompanied by class uprisings second, political and social transformation.Butwhich changes in the social structure does she mean? It is known that social structure changes continually. A person is a unit of society. In that sense birth and death of a person is also a change in social structure. Consequently, were talking about peculiar types of transformations in society. Skocpol wrote that the changes in society are attend by class uprisings. The fact that two events in society took place at the same time doesnt mean that one is a result of another one. In contrast with her idea I can state that the social changes happened during social revolutions are definitely the sequels of insurrection.The nature of a social revolution can be best evaluated by the outcomes which are concluded immediately aft(prenominal) an insurgency by downtrodden class below. For instance, the nature of the French revolution can be best estimated by process befall after the overthrow of the king. However, it is possible to discuss the upheavals of the downtrodden classes, but also about counter-revolutionary upheavals. Symbolically, we can call them rebellions. Best example is the rebellion of Franco, as result of which a civilised war has begun in Spain. Consequently, I can claim that the upheavals of the downtrodden are the inherentsegment of a social revolution.Another point regarding social revolutions which wasnt clarified in the article is about achievement of ultimate goal. Should the notion revolution be used for the instances when the downtrodden are finally nullified, or are not able to hold on to the power? Was 1905 events a revolution if to take into account that resistance of revolution was broken and it didnt manage to accomplish its goals? Skocpol considers political revolutions different from social revolutions.As an outcome of the latter, the form of the government ( and the government itself) is changed but the social structure and the property relations remains intact. Actually, political revolutions even doesnt fit the term revolution from Skocpols perspective.As a conclusion of article we can define social revolutions asa) an outcome , but also an origin of a scientific revolutio n,b) entails qualitative and quantitative transformations which become inalterable,c ) the downtrodden class can try to make changes any times before succeeding,d) representatives of this class come to government,e) social revolution continues in the consequent transformations in society.Terrorism as another widespread form of political violence can be analysed and also defined in different contexts such as religion, war, crime an etc. Some aspects of terrorism are going to stay outside of the outlook you used to study this term. I focused on the M.Chrenshaws article and can say that I appreciate the outlook she used in her article to describe the causes of terrorism. The main detectable and important moment is that she didnt used populist reasoning , like education level of terrorists or their physiological status, for justifying her arguments which I ideate makes her article a high-quality paper. But I still want to challenge some points she made regarding the causes of terrorism . Chrenshaw took modernization and grievance as one of the origins of this form of political violence.Modernization as a precondition can be taken as a factor only in states with less developed and conservative societies with stereotypes and taboos where new scientific innovations are being impose by globalization wave. Conservative people has some distrust to new lifestyle, policies and dont want to give up their traditional life. But I dont agree with the statement, in a sense that, Chernhaw missed intervening variable .It is not modernization itself causes terrorism, or else it is just content of human character to resist to transformations and adjust to new way of life. Thats why revolutions which are rapid changes in social structure preceded with terror either by state in order to impose changes on people or by group of people for stopping that change. until now reactionary changes can lead to revolution. In other sense, revolution is a good condition for terrorism to rise. The article publish in Foreign personal matters journal states that After Tunisian uprising ,which usually depicted as revolution( but just a political revolution according to Skocpols definition) , al radix got greater operational freedom of action, its followers probably will try to stir up and benefit from new uprisings in order to fight for their political goals. (Byman, 2011). The similar trends are noticed in all places where revolution happened.As a direct condition for terrorisms grievance is very important an I think that it is the factor which is a condition for other direct causes to emerge .Grievance can be conceptualized as a real or assumed wrong or other cause for discontent or protest. I appreciate Crenshaws argument about grievance and want to develop it more, that terrorists are driven by grievances about international political issues within particular regions and the world. They nourish a radical will to sacrifice innocent civilians because they ardently dream to expose their feelings and the only way of realizing them is terrorism.Off course, there can be various reasons why people nurse grievance. Some people are religious, some are nationalistic ad etc. Most probably popular reasons described as causes of terrorism such as education and poverty level therefore is not competent to explain the motives of terrorism.There isnt any concrete formula of grievance as in different societies there are people who are ready to ordain his life to some goals. If to exclude one origin of grievance, many other factors will serve as an origin to nurse grievance in a violent way.Thats why it is hardly possible to prevent the emergence of grievance but is possible to prevent terrorism by fighting against institutionalise terrorist groups. Because terror institution is a safe environment where grievance can be directed to violence path while that radical feeling can be used in favour of humankind as well.But what about variables like poverty and lack of education which are the explanations often supply by mass media and politicians? In reality more highly educated people are those who are aware of their rights and freedoms and persistent enough to fight for their political intentions to be carried out. For instance, results from public opinion polls on support for attacks against Israeli targets conducted in the West Bank and Gaza Strip indicate that support for violent attacks does not decrease among those with higher education and higher living standards. (Krueger, Alan B. Jitka Maleckova., 2003)High education level in the country promises many favourable things for its people, but analysis of the facts suggests that it doesnt direct about complete consensus and welfare in a society.If we want to look at the terrorism from the window of education we should concentrate on its content, rather than and educational level of the country.Terrorism and Revolution also other forms of political violence dont have clear border by w hich we can easily identify them. Because all this terms are socially contracted. For example, Babek for Azerbaijanis is a hero, but for Arabs he was just a rebel, for Italians Juli Sezar is a hero but for French people he is an enemy conquer, Attila for Turks is a great hero but for Europeans he is a wild , cruel barbarian king who occupied their territory, position troops in Baku in early 20th century were considered as enemies during Soviet times , but friends after independence . The same is legitimate for terrorism. For someone somebody can be a terrorist, for another one he can be a fighter for freedom. This socially constructed character of political violence makes it difficult to define and its analysis depends on the context.BibliographyByman, D. (2011). Terrorism After the Revolutions.. Foreign Affairs.Krueger, Alan B. Jitka Maleckova. (2003). Education, Poverty And Terrorism Is There A Causal Connection?. diary of Economic Perspectives.

Effects of the Expansion of Starbucks

Effects of the Expansion of Starbucks1. Background informationStarbucks has expanded rapidly since 1995. Yet, as a dissolving agent of the economic crisis causing a decline in sales, Starbucks was forced to take measures that enable it to cope with this economic crisis. (Jannarone, J. June 14 2010)2. Effect of Starbucks expanding2.1 Effect on the PPF( produceion Possibilities Frontier) sheer Starbucks has expanded at a very fast rate, adding stores in the US at an annual rate of 27% from 1995 to 2005.( Jannarone, J. June 14 2010)This would nonplus the PPF(Production Possibilities Frontier) curve for the goods of Starbucks to shift outwards as shown in the diagram below delinquent to the increase in the measure of resources being put into the production of goods since stores atomic number 18 categorize under capital resources.(Assume that Starbucks induce only two goods, umber and cake)2.2 Effect on the market engage and supply curveThe expansion also caused the supply curve o f the goods of Starbucks to shift to the discipline due to the increase in the number of suppliers (shops). This has resulted in an increase in supply of the goods of Starbucks. The equilibrium market scathe would fall while the equilibrium quantity would increase as shown in the diagram below. The blue thin lines indicate the equilibrium harm and quantity.Q-quantity, P-price, E-equilibrium point, S-supply3. Market structure of Starbucks The market structure that Starbucks is operating in is oligopoly. The following are the reasons which lead to the conclusion.3.1 Number of sellers in the marketStarbucks is a large firm operating in a many different countries. It supplies nearly of the speciality coffee in the world. There are also very few competitors such(prenominal) as MacDonald and Coffee Bean which are competing with Starbucks for its customers whom are in the first place well-off working professionals.3.2 Substantial barriers to entry for new firmsIt is very difficult for a newcomer to set up a speciality coffee arrange in the world as follow is very high. For example, advertising the new coffee product would take a huge amount of money. Researching and coming up with a new coffee product may take years and follow some a few million to a billion dollars. save it is very hard for newcomers to compete for customers with established firms like Starbucks as these firms already make believe an established brand name. As such customers would rather drink the coffee at these firms instead of others as they trust the quality of the coffee there.3.3 Mutual interdependenceSome of the actions taken by Starbucks competitors depend on the actions taken by Starbucks. It means that firms in an oligopoly weigh the effects of its own behaviour on the other firms behaviour. For example as a result of Starbucks having espresso-based drinks, McDonald decided to launch espresso-based drinks too. (Jannarone, J. June 14 2010)3.4 Type of oligopolyStarbucks is a diffe rentiated oligopolist due to the fact that evidence in the newspaper articles seems to suggest this. For example McDonald has launched espresso-based drinks but this has hardly affected Starbucks sales. (Jannarone, J. June 14 2010). This is due to the fact that Starbucks espresso-based drinks may have different somatic qualities such as a better taste compared to the ones offered by McDonald. Therefore Starbucks is likely to be slight sensitive to any price changes of its competitors products as the products it offers are different compared to its competitors products.4. Behaviour of StarbucksStarbucks practices non-price competition which means that it designs itself to increase its share of the market without changing the price of its products. This target be seen from the fact that when McDonald launched espresso-based drinks, Starbucks sales at stores swung positive in the past some(prenominal) months even though it did non decrease the price of its products. (Jannarone, J . June 14 2010) here(predicate) are some of the possible ways Starbucks practice non-price competition through product differentiation.4.1 Physical differencesStarbucks products are of better quality compared to its competitors. An example could be that Starbucks espresso-based drinks have a better taste compared to McDonald coffee. This can be seen from the fact that even though McDonald launched espresso-based drinks in 2009, Starbucks sales at stores swung positive in the past several months. (Jannarone, J. June 14 2010).This shows that generally Starbucks products are of better quality compared to its competitors products.4.2 LocationStarbucks outlets are normally located at areas where the competitors outlets are not located. This can be seen from the fact just 23% of US Starbucks locations have a McDonalds outlets within a quarter-mile radius. (Jannarone, J. June 14 2010)This makes it difficult for their regular customers and even future customers to switch to other alternati ves.4.3 Product imageStarbucks has also fostered in people mind that it provides coffee that is of the highest quality. This is done through advertising.4.4 Reasons for Starbucks behaviourStarbucks is doing this as it does not want to have a price competition with its competitors. This is because if a price war occurs, Starbucks would be forced to lower the prices of its products, causing the price to be lower than the marginal cost of producing each of its products. This would cause it to lose a lot of revenues and the total revenue earned may be much lower compared to the total cost incurred. As such Starbucks would be operating at a loss and might even close fine-tune.5. Effect of economic fadeout on Starbucks5.1 Income elasticity of customers of StarbucksStarbucks customers demand for the goods of Starbucks is income elastic. This is because during the economic recession where many of Starbucks customers suffer a decrease in their incomes, sales of Starbucks goods began to wea ken, resulting in a 9% decrease. (Cain Miller, C. January 28, 2009)It came to the point where Starbucks was forced to retrench. (Jannarone, J. June 14 2010) As such in conclusion, the absolute value of the income elasticity of demand of customers of Starbucks for the goods of Starbucks is above 1.This shows that customers of Starbucks are very responsive to any change in their income in their demand for Starbucks goods. As a result, the demand curve for Starbucks goods would shift to the left by a lot.5.2 Starbucks closing down storesStarbucks has closed down 300 stores, causing about 700 of its employees to lose their jobs in 2009. (Cain Miller, C. January 28, 2009)This is because in the short-run, at the point of output where the marginal revenue is equal to the marginal cost, the price per output of Starbucks is below the average variable cost. As such Starbucks is not able to cover part of its variable costs and its total stiff cost. Therefore Starbucks loss would be part of it s variable costs that it is not able to cover and its total fixed cost if it decides to continue on production. However if Starbucks shut down its stores, its loss would be just the total fixed cost. Therefore to minimize loss, Starbucks has decided to close down some of its stores.Starbucks PPF(production possibilities frontier)curve would shift inward as the quantity of resources being put into the production of its goods is decreased since retrenching bequeath reduce the amount of labour being employed and closing down stores would reduce the amount of capital being put into the production of Starbucks goods. This can be seen from the diagram.(Assume Starbucks produce only two goods, coffee and cake)5.3 Effect of recession on demand for Starbucks goodsIn the first quarter of 2008, Starbucks revenue has decreased from $2.77 billion to about $2.6 billion and sales at Starbucks stores decreased by about 9% (Cain Miller. January 28, 2009). This is due to the fact of expectations of its customers. Starbucks customers expect their money income to decrease as a result of the economic recession. As a result, they would buy less of Starbucks goods as a result of their anticipation of a decrease to their money income. This would cause the demand curve for Starbucks goods to shift to the left, resulting in a decrease in the equilibrium price and quantity.5.4 Starbucks cutting down on costStarbucks also has tried to cut down on cost. This include cutting down on variable costs such as reducing the salaries of employees such as Mr.Schultz , cutting down on fixed costs by renegotiating prices with landlords and suppliers. (Cain Miller, C. January 28, 2009). This would cause the supply curve of Starbucks to shift to the right as a result of the decrease in resource price such as labour, as a result of this, market equilibrium price would decrease and the equilibrium quantity would increase due to decrease in the cost of production. Starbucks is doing this so as to reduce its total cost by about $400 million to $500 million. (Cain Miller, C. January 28, 2009).This also has enabled Starbucks to increase its operating pull ahead margins from 0.6% to about 4.5 % (Cain Miller, C. January 28, 2009). Such measures has enabled Starbucks to increase its (total revenues-total cost) difference. As such gap between total revenues curve and total cost curve would be larger due to the decrease in cost.6. Conclusion6.1 Economic profitsStarbucks is an oligopolist it would in the long-run have an economic profit due to substantial barriers to entry such as a high start up costs and the presence of established brand names. As a result, lesser firms would enter the market that Starbucks is operating in. lesser number of Starbucks customers would get snatched away, therefore demand for Starbucks goods would not reduced by a lot, as such Starbucks would still earn an economic profit6.2 Allocative aptitudeStarbucks cannot attain allocative efficiency as the price of i ts goods are larger compared to the marginal cost associated with producing that good. This show that consumers are paying an amount that is larger compared to the additional cost of producing a unit of Starbucks good. Therefore consumers would be better off if Starbucks produce more of its goods.6.3 Challenges faced by StarbucksStarbucks faced a declining demand for its goods as consumers straight prefer healthier drinks. However Starbucks emphasizes on milky, sugary drinks, hurting its image as an authentic coffee house. (January 28, 2009)This would result in Starbucks demand curve break to the left due to the taste and preferences of consumers, resulting in the decrease of equilibrium price and quantity.Starbucks has also expanded by a lot this has resulted in it experiencing diseconomies of scale as more layers of management are needed to coordinate the Starbucks operations. This would result in a higher cost for Starbucks as a larger amount of resources is take to coordinate and manage resources such as labour.Starbucks may have also experienced the law of diminishing returns which is as more and more variable inputs are added into the fixed resource of Starbucks such as its stores, marginal product of the additional variable input would ultimately decline due to congestion and crowding. This is shown when the marginal physical product curve is decreasing from its maximum point. This would also result in it experiencing increasing marginal costs as shown in the diagram. This is shown by the marginal cost curve increasing from its minimum point.6.4 Starbucks strategiesStarbucks has shown that it is capable of adapting to situations. For example, during the economic recession, it cut down on cost. It also attempted to attract more customers and retain existing ones by giving special offers such as giving loyalty cards that provide discounts and coming up with breakfast combination meals. (Cain Miller, C. January 28, 2009).Starbucks has also attempted to give away its market reach by opening new stores in new markets such as China. Many of those stores have matured and operating profits could briefly be earned from them. (Jannarone, J. June 14 2010)To cut down on cost as well as diseconomies of scale, it also has shut down 300 stores. (Cain Miller, C. January 28, 2009)6.5 afterlife of StarbucksStarbucks has proven itself to be capable of adapting to situation while attempting to take the initiative in taking advantage of new opportunities. This shows that despite challenges such as declining demand for its products, Starbucks is still capable of remaining competitive.

The Pros and Cons of Teaching Sex Education in Public Schools Essay

Picture a young couple being on the verge of exploring their knowledgeable desires for the first time. The question is does this young couple have the proper instruction to make this life changing decision? They most likely were given their education from the school they attend. Hopefully the school taught them what they needed to know to make such a decision. Should sex education be taught at school by get worders or by the parents? Problems with having sex education at school There are many problems with having sex education in public schools. Religion plays an important lineament to the topic of sex education. Some parents feel that if the school gets to speak to their children about sex before they do, than important things about their religion will be left wing out of the discussion. If their religion says not to have premarital sex, then that child doesnt need to learn the proper way to put on a condom, where to go to get birth control pills, or anything about abortion. None of this information is going to be needed because the child of the family who uses religion as a road map for everyday life. These children dont need their heads filled with what isnt important in their religion. According to the Web page SIECUS, parents are-and ought to be-the primary sexual urge educators of their children. From the moment of birth, children learn about love, touch, and relationships. Infants and toddlers receive sexuality education through example when their parents talk to them, dress them, show affection, play with them, and teach them the names of the parts of their bodies (Sexuality). Another reason parents want to teach their children about sex education is that they feel it is up to them and no one else to teach their kids ... ...ks Cited Cooper, Carol. What shall we tell the children? The Lancet 356 (2008) 780. Does Sex Education work? AVERT 18 Nov. . Harris, Wendy. Schools fail sex ed, new studies say Parents, students want more comprehensive les sons even as scope of teaching has narrowed. Spokesman Review 27 Sep. 2007 A1. Jordan, Timothy R. unsophisticated parents communication with their teen-agers about sexual issues. The Journal of School Health 70 (2008) 338-344 Schemo, Diana J. Survey Finds Parents Favor More Detailed Sex Education. The New York Times 4 Oct. 2007 A.1 Sexuality Education is the Schools Issues and Answers. SIECUS Report 27 (2007) Web. 19 Nov. 2008 http//www.siecus.org/pubs/fact/fact/0007.html. Ubell, E. Sex-education programs that work-and some that dont. Parade Magazine 12 Feb. 2007 18-20.

Alzheimers Disease Essay -- Alzheimers Disease Essays

Alzheimers DiseaseAlzheimers is a disease of the brain that causes a stunner decline in memory. This results in dementia, which is loss of intellectual functions toilsome enough to interfere with everyday life. Alzheimers disease is the most common cause of dementia, impact ten percent of people over 65 jump on old, and nearly 50 percent of those age 85 or older. My grandmother was diagnosed with probable Alzheimers disease over two years ago. After conclusion this out, I wanted to know more about this particular disease.Alzheimers disease unremarkably begins gradually, causing a person to forget recent events and to crap difficulty performing familiar tasks. How rapidly the disease advances varies from person to person. Communication becomes difficult as the person with Alzheimers struggles to find words, finish thoughts, or look on directions. Eventually, people with Alzheimers become totally unable to care for themselves. My grandma is very clam up to this point.Scientis ts are dumb not for certain what exactly causes Alzheimers disease. Research suggests that the central problem is malfunction and death of nerve cells, but scientists are still working to learn why this happens. Key areas of study concentrate on biochemical processes and pathways in nerve cells, effects of inflammation, and the influence of genes. Many experts believe that it normally arises form a complex combination of factors.Increasing age is the greatest known risk factor f... Alzheimers Disease Essay -- Alzheimers Disease EssaysAlzheimers DiseaseAlzheimers is a disease of the brain that causes a steady decline in memory. This results in dementia, which is loss of intellectual functions severe enough to interfere with everyday life. Alzheimers disease is the most common cause of dementia, affecting ten percent of people over 65 years old, and nearly 50 percent of those age 85 or older. My grandmother was diagnosed with probable Alzheimers disease over two year s ago. After finding this out, I wanted to know more about this particular disease.Alzheimers disease usually begins gradually, causing a person to forget recent events and to have difficulty performing familiar tasks. How rapidly the disease advances varies from person to person. Communication becomes difficult as the person with Alzheimers struggles to find words, finish thoughts, or follow directions. Eventually, people with Alzheimers become totally unable to care for themselves. My grandma is very close to this point.Scientists are still not for certain what exactly causes Alzheimers disease. Research suggests that the central problem is malfunction and death of nerve cells, but scientists are still working to learn why this happens. Key areas of study focus on biochemical processes and pathways in nerve cells, effects of inflammation, and the influence of genes. Many experts believe that it usually arises form a complex combination of factors.Increasing age is the greatest kno wn risk factor f...