Science and its Impact on Society Essay Example | Topics and Well Written Essays - 1000 words

Science and its Impact on Society - Essay Example However, in the recent past, there has been a growing awareness among society that the effects of science and related research are not always beneficial. The perception amongst people is that science will only lead to the destruction of nature eventually. That no matter what advancement in technology is enjoyed; the harmful effect on our planet in the name of research and science is increasingly being felt. Only those aspects of science receive attention in society which suit the goals or which inspire awe - this indicates that people at large read science because it serves their purpose or because the subject is topical, sensational or controversial. At most, only a handful read science for the sake of the knowledge it might impart. Much research is required to identify those subjects so that science could be made more popular and effective. Science was a great investment towards a better life and this resulted in the discovery of light waves and radio waves, the electric motors, the first photograph and telephone, and the first publication of the periodic table. There was also great controversy when Charles Each society is faced with the challenge of keeping its proper place in a world defined by economic and political change. Knowledge, in particular science, technology and innovation, is indispensable to meet this challenge. Scientific and technological progress results in new innovations that are an integral part of international competitiveness. This translates into what the society's needs and aspirations are, such as peace, jobs, security, health and sustainable development of the planet. Viewing science from two angles: The benefits are many: medical advancements have saved many lives; internet and increased access to information is definite; research in the field of weather has led to the predictions of storms and the study of astronomy has given society knowledge of the formation of Earth and of the solar system. The adverse effects are: The medicines prescribed come with their own side effects; and nuclear technology! This scientific knowledge has helped in creating bombs which are used for massacres and gruesome killings; it has also been used for energy, releasing radiation which causes medical problems to many. Factors controlling the usage of science: The relationship between science, controlled by the government, and society is a hostile one because the society that enjoys benefits of science cannot do anything to prevent the side-effects of science - it is powerless to take action to curb the harmful turn of events that result from science; especially more so if the science is

Biodiversity Research Paper Example | Topics and Well Written Essays - 1250 words

Biodiversity - Research Paper Example The disturbance in the balance is due to the disturbance in the food chain. Like in a forest ecosystem, none of the animal is valueless; lamas, zebras, buffaloes and deer are eaten by tigers, lions, leopards and jaguars. If the ecosystem faces the extinction of the lions, tigers, jaguars or leopards, the number of lamas, zebras, buffaloes and deer increase rapidly and thus there would be low food resources for them and animal will die from diseases, which will make the ecosystem unhealthy. Natural Alteration in the Ecosystem Natural occurrences like earthquakes, droughts, etc have heavy impact on the ecosystems. Natural occurrences can produce alterations to the ecosystem. Like the droughts become a reason for the shortage of food (Shah, 2011). The shortage of food may bring some of the creatures to extinct. However, some of the alterations are good for the environment and some of the alterations are worst in terms of extinctions of some of the creatures. Importance of Biodiversity B iodiversity is often considered to have no linkage with the economic sustainability. However, environmental sustainability is often thought to have a connection with the biodiversity. In fact, biodiversity is connected to economic as well as environmental sustainability (Shah, 2012). It can provide food, water and a healthy atmosphere. A decline in the biodiversity of the planet would bring many problems. Biodiversity, Food Resources and Economics Most of the food resources come from the biological resources. If the biological resources regarding the food become less, then there would be a lot of hunger and disease. In this way, it is almost impossible without the utilization of food resources. The economics of a country are largely linked the production and utilization of the food resources. The more the food resources a country has, the more food there will be to export and earn money, to boost the economy. Results show that forty percent of the world’s economy is dependent on the biological resources. However, paper, textile and timber industry will also remain incomplete without preserving biodiversity. In this way, industrial economy depends much on biodiversity, while tourism increase due to forests and preserved marine life. Biodiversity and Medicine Biodiversity has much importance in terms of medicines, as most of the medicines come from the plant and animal sources. The medicines like coniine, etc, which is utilized in the malarial disease come from the plant. The research and development in the field of medicine is totally incomplete without biological resources. In this way biological resources have much importance in the field of medicines. Biodiversity and Climate Change Climate change is one of the biggest threats to the biodiversity of the planet. Some creatures like coral are much sensitive to the small change in the temperature and a little increase in the temperature could become a cause of the death of coral reefs. Coral are importan t in providing many fish and some other marine creatures a shelter and thus extinction of the coral means the extinction of many other species too (Harris, 2012). However, the protection of the biodiversity can only be a factor in controlling the climate change, as the major

Card Game Essay Example for Free

Card Game Essay The study was commenced inside the Computer Shop at Dasmarinas, Cavite. After we discussed our first topic we planned to come up with a Card Game as our second topic for the sake of our thesis project in Software Engineer Subject. We picked Card Game as our second topic because we feel that it’s more challenging rather than hunting some companies around Dasmarinas. Some of the reasons why we picked Card Game as our second topic are because in this topic we own our time performing the codes of the program any time before the day of our defence without such pressure. Statement of the Problem From some of the research and data we gathered. We found a few application and websites that is running a similar online game like our propose topic. From what weve seen some major problem that they have is that the game is not quite user friendly. Its difficult to use the control. Because of the lack of visual control buttons. There is also limitation on how many game can it accommodates at the same time. Of course keeping the gamers idle for so long they might lose interest in the game Research Objectives The Objectives of this research is to develop a game that will be entertaining and at the same time, a game that will be educational that may enhance thinking and decision-making skill in the following ways: * To make unique cards in the game that will allow diversity for the players to think of their own strategy. * To ensure that players will have no advantage against each other by making cards balance. * To allow multiplayer (online) for players to play against each other in different parts of the world. Significance of the Study Cardfight vanguard is a trading card game there are also people who wants to experience playing this game but doesnt have the luxury of buying the needed cards and also looking for people to play with. Since people now are more often browsing the internet people who want to play Vanguard can play the game without buying the necessary cards needed and having to worry of looking for someone to play with. Conceptual Framework * PHP Hypertext Preprocessor. * Randomized * Easy access * Less hassle Electronic Trading Card Game The model above explains on what and how will be the process of the study. Trading Card Game is a game played using specially designed sets of playing cards. While trading cards have been around for longer, TCGs (Trading Card Games) combine the appeal of collecting with strategicgameplay, but in our study we will do it in a different way by using PHP Hypertext Pre-processor as our scripting language for this study and for our main function for this logical game is the random() function. The researchers will assure an easy access program for the user and it lessens hassle because rather than bringing your deck of cards using your bare hands, just bring your portable computer and start playing the game on your most comfortable place.

Fuel Metering System In Si Engines

Fuel Metering System In Si Engines Carburetor: is a device which is used in automobiles, with spark ignition engines, for the purpose of fuel metering, i.e. to mix the appropriate amount of fuel with the incoming air which is to be supplied to the engine cylinders. The basic principle upon which the carburetor works is flow of air through the venturi. The fuel enters the carburetor through the air filter, which filters the air to remove any dust particles in the air; passing through the choke valve it enters the venturi (a converging-diverging nozzle), where due to decrease in cross-sectional area, the velocity of the air increases, decreasing the pressure in that area. A decrease in the pressure results in fuel flowing out of the float chamber and mixing with the air, hence forming an air-fuel mixture. Figure . Cross-sectional view of a basic carburetor Basic Requirements: In a spark ignition engine the torque and power output of the engine is controlled by controlling the amount of air-fuel mixture that enters the engine cylinder; and this is done by incorporating a butterfly valve (throttle valve) in the carburetor. In order to achieve complete combustion inside the engine cylinder and avoid the wastage of fuel into the exhaust, a stoichiometric mixture is required; which is a mixture that contains precise proportions of fuel and air required for the complete combustion of both the fuel and the air, which is equally important. In gasoline engines, this ratio is around 15:1. Even if this ratio is achieved, practically the mixture is still not combusted completely owing to the extremely short time available to the air-fuel mixture for combustion. The air-fuel mixture is unable to form a completely homogenous mixture resulting in exhaust gases containing traces of oxygen, carbon monoxide and some unburned and partially burnt fuel. The range of air-fuel ratio for ignitable mixture varies from 18:1 to around 7:1. The basic purpose of using a carburetor is to: Measure the airflow of the engine Deliver the correct amount of fuel to keep the air-fuel mixture in the proper range Mix the air and fuel finely and evenly The proper air-fuel mixture is required to be delivered to the engine cylinder at the various commonly faced conditions during the vehicle operation, namely: Cold start Hot start Idling or slow-running Acceleration High speed/high power at full throttle Cruising at part throttle The deficiencies of the elementary/early carburetor: At low loads the mixture becomes leaner; the engine requires the mixture to be enriched at low loads. At intermediate loads, the mixture equivalence ratio increases slightly as the air flow increases. The engine requires an almost constant equivalence ratio. As the air flow approaches the maximum wide-open throttle value, the equivalence ratio remains essentially constant. However, the mixture equivalence ratio should increase to 1.1 or greater to provide maximum engine power. The elementary carburetor cannot compensate for transient phenomena in the intake manifold. Nor can it enrich the mixture during engine starting and warm-up. The elementary carburetor cannot adjust to changes in ambient air density (due primarily to changes in altitude). Modern Carburetor Design: The changes required in the elementary carburetor for better and more efficient performance are: The main metering system must be compensated to provide essentially constant lean or stoichiometric mixtures over the 20 to 80 percent air flow range. An idle system must be added to meter the fuel flow at idle and light loads. An enrichment system must be added so the engine can provide its maximum power as wide-open throttle is approached. An accelerator pump which injects additional fuel when the throttle is opened rapidly is required to maintain constant the equivalence ratio delivered to the engine cylinder. A choke must be added to enrich the mixture during engine starting and warm-up to ensure a combustible mixture within each cylinder at the time of ignition. Altitude compensation is required to adjust the fuel flow to changes in air density. It is also necessary to increase the magnitude of the pressure drop available for controlling the fuel flow. Figure . Modern Carburetor design Basic Working and different parts of the Carburetor: Figure . Simple Carburetor with additional basic features 1) Float 2) Float needle 3) Float chamber 4) Main jet 5) Air tunnel(venture) 6) Throttle plate ( a. no-load operation) b. partial load; c. full load) 7) Air correction nozzle 8) Mixing tube 9) Mixing tube holes 10) Enrichment pipe 11) Jet (calibrated drilling) 12) No-load operation fuel nozzle 13) Idle run air duct 14) Idle mixture adjustment screw 15) Bypass drilling 16) Accelerator pump 17) Choke (for cold start) 18) Ventilation A carburetor basically consists of an open pipe, a throat/barrel through which the air passes into the inlet manifold of the engine. The pipe is in the form of a venturi; it narrows in section and then widens again, causing the airflow to increase in speed in the narrowest part. Below the venturi is a butterfly valve called the throttle valve (a rotating disc that can be turned end-on to the airflow), so as to hardly restrict the flow at all, or can be rotated so that it almost completely blocks the flow of air. This valve controls the flow of air through the carburetor throat and thus the quantity of air/fuel mixture the system will deliver, thereby regulating engine power and speed. The throttle is connected, usually through a cable or a mechanical linkage of rods and joints or rarely by pneumatic link to the accelerator pedal on a car or the equivalent control on other vehicles or equipment. Fuel is introduced into the air stream through small holes at the narrowest part of the venturi and at other places where pressure will be lowered when not running on full throttle. Fuel flow is adjusted by means of precisely-calibrated orifices, referred to as jets. Idle circuit: As the throttle plate is opened slightly from the fully closed position, the additional fuel delivery passages are uncovered behind the throttle plate. The low pressure area is created due to the throttle plate blocking the air flow; this allows more fuel to flow as well as compensating for the reduced vacuum that occurs when the throttle is opened. This smoothens the fuel flow through the jets when moving from closed throttle position to the open throttle circuit. This circuit plays its role when the engine is running on no load condition or is known as idling. The air enters from the idle run air duct, certain amount of fuel is mixed with this air depending on the no-load operation fuel nozzle and then goes into the intake manifold through the idle mixture screw path. This idle mixture screw is adjusted to regulate the amount of air-fuel mixture when idling. Main open-throttle circuit: When the throttle is opened, the vacuum inside the manifold decreases due to decreased restriction in the airflow. This reduces the flow through the idle and off-idle circuits. The airflow through the throat increases, and in accordance with the Bernoullis principle the pressure drops in the throat and the fuel flow through the jet, which is placed in the centre of the venturi, increases. Similarly, when the throttle is closed, the airflow through the venturi drops till the point when the lowered pressure is insufficient to maintain the fuel flow, and the idle circuit takes over. At times booster venturis are used to enhance the fuel flow out of the jet and into the air stream. Accelerator Pump: The inertia of the liquid gasoline is more than that of the air, which shows that when the throttle is opened suddenly during sudden acceleration, the amount of air that will flow would be far greater than the amount of fuel flow resulting in a temporary lean mixture, causing the engine to stumble under acceleration. This is not a desirable effect. In order to eliminate this unwanted effect, a small mechanical pump usually of diaphragm type is employed. It propels a small amount of gasoline through a jet, from where it is injected into the carburetor throat. This extra shot of fuel counteracts the transient lean condition during sudden acceleration. The accelerator pump is also used to prime the engine with fuel prior to a cold start. Excessive priming, like an improperly-adjusted choke, can cause flooding. This is when too much fuel and not enough air are present to support combustion. For this reason, some carburetors are equipped with an unloader mechanism: The accelerator is held at wide open throttle while the engine is cranked, the unloader holds the choke open and admits extra air, and eventually the excess fuel is cleared out and the engine starts. Choke: when the engine is cold, the fuel does not vaporize properly, instead it condenses on the walls of the intake manifold, and hence very little fuel is delivered to the cylinders. This makes it difficult for the engine to start. This calls for the need of a richer mixture to start and run the engine until it warms up, as the richer mixture is easier to ignite. Figure . Cross-sectional view of a choke To provide the extra fuel, a choke is typically used. It is a device that restricts the flow of air at the entrance to the carburetor, before the venturi. With this restriction in place, extra vacuum is developed in the carburetor barrel, which pulls extra fuel through the main metering system to supplement the fuel being pulled from the idle circuit. This provides the rich mixture required to sustain operation at low engine temperatures. Even in this era of advanced technology, cars like Suzuki Mehran still employ a choke which is connected to a pull-knob on the dashboard operated by the driver. In some carbureted cars it is automatically controlled by a thermostat employing a bimetallic spring, which is exposed to engine heat, or to an electric heating element. This heat may be transferred to the choke thermostat via simple convection, via engine coolant, or via air heated by the exhaust. More recent designs use the engine heat only indirectly: A sensor detects engine heat and varies electrical current to a small heating element, which acts upon the bimetallic spring to control its tension, thereby controlling the choke. A choke unloader is a linkage arrangement that forces the choke open against its spring when the vehicles accelerator is moved to the end of its travel. This provision allows a flooded engine to be cleared out so that it will start. Some carburetors do not have a choke but instead use a mixture enrichment circuit, or enrichener. Typically used on small engines, notably motorcycles, enricheners work by opening a secondary fuel circuit below the throttle valves. This circuit works exactly like the idle circuit, and when engaged it simply supplies extra fuel when the throttle is closed. Float chamber: To ensure a ready mixture, the carburetor has a float chamber or bowl that contains a quantity of fuel at near-atmospheric pressure, ready for use. This reservoir is constantly replenished with fuel supplied by a fuel pump. Float: The correct fuel level in the bowl is maintained by means of a float controlling an inlet valve. The fuel arriving from the tank is held inside a constant level float chamber. The liquid pressure head on the various jets is relatively constant. The float chamber level is kept constant by means of a fuel inlet valve, actuated by a float that follows free surface of the liquid in the float chamber. As fuel is used up, the float drops, opening the inlet valve and admitting fuel. As the fuel level rises, the float rises and closes the inlet valve. By having a high float level, a greater fuel quantity is delivered compared to the case with a low float level, under all operating conditions and for all of the carburetors circuits. Vent Tubes: Usually, special vent tubes allow air to escape from the chamber as it fills or enter as it empties, maintaining atmospheric pressure within the float chamber; these usually extend into the carburetor throat. Placement of these vent tubes can be somewhat critical to prevent fuel from sloshing out of them into the carburetor, and sometimes they are modified with longer tubing. Notch Pin: With this type of carburetor, the maximum depression zone is beneath the throttle valve (slide) which is raised and lowered by the throttle cable, controlling the speed of the engine. As shown in the drawing, the bottom of the slide features a tapered needle which fits into the fuel pick-up tube (needle jet) to meter the fuel delivery of the tube from about 1/4 throttle to 3/4 throttle. From 3/4 throttle to full throttle, the needle will not affect the fuel flow. At this point, fuel flow is metered by the main jet (position at the bottom of the tube). The setting of the notch determines the amount of fuel being allowed to mix with the incoming air; notch 1 providing a lean mixture and richer mixture as we proceed to notch 4. Figure 11. Notch Pin Types of Carburetors: Carburetors can be classified into three types: Float Feed Suction Feed/Diaphragm Constant Vacuum/Constant Depression/Zenith-Stromberg The difference between these is the way the fuel is supplied to the Air Stream. Float Feed: Float feed carburetors are so named because they maintain a fuel staging area at approximately ambient pressure with a float valve. Fuel level is maintained to tight tolerances because fuel metering is a function of float level. Higher levels make it richer. Figure 12. Operation of needle valve As the fuel is drawn for the bowl area the float drops, opening the float valve. Then the fuel pump pressure causes the bowl to refill, floating the valve closed. Under normal operations the float valve remains slightly open to very open, keeping the level constant. Floats can be concentric or eccentric. Concentric are levers, first or second class, whereas eccentrics are a slide float. Floats can be adjusted by shims under the valve or by adjusting a valve contact tab. Floats need to be carefully inspected for leaks and possible deterioration. The main source of fuel metering force comes from the pressure differential between the low pressure area within the venture and the ambient pressure in the float chamber, or bowl. This is called air metering force. Figure 13. Air-metring force being applied Idle circuits will exist that feed fuel through separate ports. These are located just downstream of the throttle plate; there may also be transition ports to assist throttle transition from idle to midrange. Idle and transition ports will only be active when throttle plate is closed or transitioning (they function only when the throttle plate is causing high velocity air or flow close to the port and once the throttle plate opens enough, the port stops delivering fuel flow); these ports usually form a completely separate fuel circuit from the main fuel metering. They may also have air bleed systems. Figure 14. Demonstration of relation between Idle circuit and main throat operation Most of these carburetors are up draft or side draft, and the systems are identical with the position of the fuel discharge venturis and idle circuits upstream of the throttle valve, regardless of the airflow direction. Figure 15. An up-draft carburetor Disadvantages: The three major disadvantages of float carburetors are: Various flight attitudes may cause the float system to malfunction. Carburetor icing is most prevalent with this type. Fuel metering and throttle transition is less accurate. Suction Feed: Suction Feed Carburetor is very similar to the float type. The one exception is there is no float to meter and control the level of fuel in the fuel chamber. The difference in pressure between the tank and the carburetor throat lifts the fuel up the fuel pipe past the main needle valve and through the discharge holes. Figure 16. Suction Feed Carburetor Figure 17. Cold Start Figure 18. Idling Constant Vacuum: The constant vacuum carburetor has a rubber diaphragm exposed to the cylinder intake stroke vacuum on one side and to atmospheric pressure on the other. The diaphragm moves against the inlet needle (cylindrical slide valve) allowing it to move from its seat. A spring returns the needle (cylindrical slide valve) to its seat when the vacuum stops. Figure . A typical Constant Vacuum type carburetor A few advantages of Carburetors: Carburetors are much easier to adjust/less technical skills required Cheaper to repair rebuild Less special equipment required. Problems with Carburetors: Have mechanical parts due to wear and tear needs periodic adjustments and maintenance. Flexibility limitations. Intake manifold length problems in the case of multi cylinder engines Carburetors arent very efficient as they cant make changes on the fly like fuel injection can. Conclusions: Keeping in mind the advantages and disadvantages of carburetor, regardless of the constant n continuous effort to improve the basic design into the most efficient one, the carburetors have finally been replaced by the latest technology referred to as fuel injectors. These fuel injectors are of various types, GDI being a personal favourite and the best technology available in the market. The fuel injectors efficiently meter the appropriate amount of fuel hence reducing the exhaust emissions, fuel wastage, the harmful pollutants and giving the best fuel economy possible.

Investigating how the concentration of reactants affects the rate of re

Investigating how the concentration of reactants affects the rate of reaction Chemistry Coursework This experiment is aimed at investigating how the concentration of reactants affects the rate of reaction: The reaction between hydrochloric acid and magnesium will be used to investigate how different concentrations of the acid affect the rate of reaction. The gas produced from the reaction will be measured and used to display the average rate of reaction. The rate of reaction is a measure of how fast a reaction is going and how long it takes to complete. This rate is found by measuring the amount of a reactant used up per unit of time or the amount of a product produced per unit of time. For this reaction, the product will be measured, as this substance is the easiest and most accurate to measure. Scientific Knowledge: A reaction can be stimulated to go faster or slower by varying the temperature, the concentration of reactant and the surface area. For the magnesium and acid particles to react together, they must: i) Collide with each other ii) Have enough energy in the collision. 1) The particles in the liquid move around continually. Above, an acid particle is about to collide with a magnesium atom. 2) If the collision has enough energy, a reaction takes place. Magnesium chloride and hydrogen will be formed. 3) If the collision does not have enough energy, no reaction occurs and the acid particle will bounce away again. Particles need to collide with enough velocity so that they react. During a chemical reaction, the particles have to collide with enough energy to first break the bonds and then to form the new bonds and the rearranged electrons, so some of the particles do not have enough energy to react when... ...make a reaction take place. (The results from the second experiment were used in order to get a more accurate data collection.) Evaluation: For future experiments, it must be noted that the gas needs to be removed from gas syringe after each test, as this was one of the problems during the investigation. If the excess gas is not removed, the experiment begins and the results are completely out of range. It was felt that this experiment may have been easier with the aid of three people, as this would mean that there were not so many activities fro each person to record or read. In order to get a more accurate result, having recorded the measurements from the experiment, the results should have been averaged, instead of using only one set. For a full conclusion to be confirmed, more tests should have been carried out to provide enough evidence to support the argument.

The Success of the Massachusetts Bay Colony Essay -- American History,

In the 1600’s, two colonies were establishing themselves on the east coast of North America. In 1607, a group of merchants, known as the Virginia Company, settled at Jamestown, Virginia on the Chesapeake Bay (Divine, 72); while Puritan leader John Winthrop, stationed himself and his followers at Massachusetts Bay in 1630. (Divine, 90) Although both settlements started off relatively the same, the greater success of one over the other has caused continuous debates between many, including the descendants of these early Americans. Some might argue that the Virginia Colony was more successful than the Massachusetts Bay Colony because of the Virginia colonists’ motivation and interest in profit (Divine, 76). However, when efforts for income proved futile, this and survival became the colony's only interests. Therefore, Massachusetts proved itself to be the stronger colony and the most successful, as a result of its community development and social advancement, its economic growth, and the positive influence the government had on the Massachusetts Colony. Instead of having scattered villages like the Virginia colony, the people of the Massachusetts Bay Colony organized communities that were small and built close together. These centers were built so that villagers were able to complete a wide range of duties such as cultivating land or fetching lumber from forests (Divine, 94). This system was especially efficient for finishing these important tasks and allowing time for other agendas that were important to the colonists. The setup of the town was not just efficient. Families were able to live close together which helped create a sense of community among the people. Taverns and meetinghouses were commonly built in town, giving the ... ...ve in Virginia did not mean immigrants were free from its rule. Upon departing England, those leaving would take an â€Å"oath of allegiance and supremacy† (Virginia Ship’s List). This meant that the people owed their loyalty to the monarch of England, not to Virginia itself. The colonists of Virginia could have been frustrated that their head official was chosen by a single person, a person who had no place within their community. In fact, Berkeley, the governor the monarch of England elected, â€Å"brought high taxes on the people, increased his power at the expense of local officials and created a monopoly on Indian trade† (Divine, 85). This abuse of power is possibly one of the causes of rebellions, specifically Bacon’s rebellion. This republic government leading the Virginia Colony was an increasingly stark contrast to the Massachusetts’ Colony’s democratic government.

Four Phases of Business Cycle Essay

Business Cycle (or Trade Cycle) is divided into the following four phases :- Prosperity Phase : Expansion or Boom or Upswing of economy. Recession Phase : from prosperity to recession (upper turning point). Depression Phase : Contraction or Downswing of economy. Recovery Phase : from depression to prosperity (lower turning Point). Diagram of Four Phases of Business Cycle The four phases of business cycles are shown in the following diagram :- The business cycle starts from a trough (lower point) and passes through a recovery phase followed by a period of expansion (upper turning point) and prosperity. After the peak point is reached there is a declining phase of recession followed by a depression. Again the business cycle continues similarly with ups and downs. Explanation of Four Phases of Business Cycle The four phases of a business cycle are briefly explained as follows :- 1. Prosperity Phase When there is an expansion of output, income, employment, prices and profits, there is also a rise in the standard of living. This period is termed as Prosperity phase. The features of prosperity are :- High level of output and trade. High level of effective demand. High level of income and employment. Rising interest rates. Inflation. Large expansion of bank credit. Overall business optimism. A high level of MEC (Marginal efficiency of capital) and investment. Due to full employment of resources, the level of production is Maximum and there is a rise in GNP (Gross National Product). Due to a high level ofeconomic activity, it causes a rise in prices and profits. There is an upswing in the economic activity and economy reaches its Peak. This is also called as a Boom Period. 2. Recession Phase The turning point from prosperity to depression is termed as Recession Phase. During a recession period, the economic activities slow down. When demand starts falling, the overproduction and future investment plans are also given up. There is a steady decline in the output, income, employment, prices and profits. The businessmen lose confidence and become pessimistic (Negative). It reduces investment. The banks and the people try to get greater liquidity, so credit also contracts. Expansion of business stops, stock market falls. Orders are cancelled and people start losing their jobs. The increase in unemployment causes a sharp decline in income and aggregate demand. Generally, recession lasts for a short period. 3. Depression Phase When there is a continuous decrease of output, income, employment, prices and profits, there is a fall in the standard of living and depression sets in. The features of depression are :- Fall in volume of output and trade. Fall in income and rise in unemployment. Decline in consumption and demand. Fall in interest rate. Deflation. Contraction of bank credit. Overall business pessimism. Fall in MEC (Marginal efficiency of capital) and investment. In depression, there is under-utilization of resources and fall in GNP (Gross National Product). The aggregate economic activity is at the lowest, causing a decline in prices and profits until the economy reaches its Trough (low point). 4. Recovery Phase The turning point from depression to expansion is termed as Recovery orRevival Phase. During the period of revival or recovery, there are expansions and rise in economic activities. When demand starts rising, production increases and this causes an increase in investment. There is a steady rise in output, income, employment, prices and profits. The businessmen gain confidence and become optimistic (Positive). This increases investments. The stimulation of investment brings about the revival or recovery of the economy. The banks expand credit, business expansion takes place and stock markets are activated. There is an increase in employment, production, income and aggregate demand, prices and profits start rising, and business expands. Revival slowly emerges into prosperity, and the business cycle is repeated. Thus we see that, during the expansionary or prosperity phase, there is inflation and during the contraction or depression phase, there is a deflation.