How Is Power Generated With Hydroelectricity?

How Is Power Generated With Hydroelectricity? Hydroelectric power energy from falling water. Hydro electric power means getting energy from flowing water. This method of energy generation is viewed as very environmentally friendly by many people, since no waste happens during energy generation. However, hydroelectric power can have a deep impact on the surrounding environment, leading some people to question the help of hydroelectric power as a method of clean energy generation. Hydroelectric power is used to run water as an energy source and mostly in grind corn. Hydroelectricity produced enough power light for two paper mills and a house. Nearly ally of the hydroelectric power stations, provide around 20% of the worlds electricity. The Origin of Hydro Power was first used in Ancient Egypt. They used flowing water to make a machine work and grind their crops. The Size of the Hydro power plants today range in size from some hundred kilowatts to several hundred megawatts. Some of the larger plants have capacities up to 10,000 megawatts and supply electricity to millions of people. Over 80 percent of all electricity produced by renewable sources is produced by large hydroelectric dams. With low carbon dioxide emissions and working costs, hydropower is an important part of a climate friendly energy mix. More sustainable sources, such as wave and tidal power, could save the standing of water based energy production. Hydropower accounts for around 20% of the worlds electricity generation, and a little over 2 percent of the worlds total energy supply. Although dams often have big environmental and social impacts, the World Wide Fund for Nature estimates that another 370 Giga watts of large, medium, or small hydroelectric capacity could be developed without unacceptable impacts by 2050. The energy output Because most dams use gravity, a hydroelectric dams energy output depends largely on the height difference between the tank water source and the outflow. Water flow along the rivers is another important factor, as is the age and efficiency of a dam. Many of the worlds older dams will need to be upgraded or repowered in the coming decades to improve efficiency, which will be expensive but could eventually add another 30 GW to the global energy mix. Environmental impact Large hydroelectric dams have a number of negative impacts on the local environment and human society. Dams disrupt river ecosystems and passages, killing aquatic life that gets caught in turbine blades. Dams also create artificial reservoirs, which floods farmland and forests, and displaces wildlife and people. Hydroelectric projects are also susceptible to fluctuations in river flows and rainfall. Which depends on energy from the Volta River Dam, has suffered severe energy shortages in recent years because of lack of rainfall. The key environmental problem with hydroelectric power is that blocking changes the natural environment. The flow of a river is basically changed when a dam is installed, posing problems for fish and aquatic plants on both sides of the dam. However, there are some arguments in support of hydroelectric power. Once installed, a hydroelectric power plant does not generate any emissions or waste, making it very much preferable to something like a coal fired power plant. The technology of hydroelectric power is also always being improved, and sometimes simple measures like fish ladders can moderate the impact of a dam. How it worksà ¢Ã¢â€š ¬Ã‚ ¦. 1. Hydroelectric power, or hydroelectricity, is generated by the force of falling water. Its one of the cleanest sources of energy and its also the most reliable and costs the least. 2. Water is needed to run a hydroelectric power-generating unit. The water is held behind a dam, forming an artificial lake. The force of the water being released from the reservoir through the dam spins the blades of a giant turbine. The turbine is connected to the generator that makes electricity as it spins. After passing through the turbine, the water flows back into the river on the other side of the dam. Basically the exciter powers the rotator. 3. Electricity is produced by spinning electromagnets within a generators wire coil that creates a flow of electrons. To keep the electromagnets spinning, hydroelectric stations use falling water. Hydroelectric power plants convert the kinetic energy contained in falling water into electricity. The energy in flowing water is ultimately derived from the sun, and is therefore constantly being renewed. As the rotator and its magnetic field turn, an electric charge is created in the stator. 4. Energy contained in sunlight evaporates water from the oceans and deposits it on land in the form of rain. Differences in land elevation result in rainfall runoff, allowing some of the original solar energy to be captured as hydroelectric power. Most hydroelectric stations use either the natural drop of the river or build a dam across the river to raise the water level and provide the drop needed to create a driving force. Water at the higher level goes through the intake into a pipe, called a penstock, which carries it down to the turbine. A transformer increases the voltage of the current coming from the starter. The turbine is a type of water wheel that converts the waters energy into mechanical power. The turbine is connected to a generator, when the turbine is set in motion it causes the generator to rotate, producing electricity. The falling water, having served its purpose, exits the generating station through the draft tube and the tailrace where it rejoins the river. Building a dam means flooding a lot of land. The sun evaporates water from the sea to the lakes. This forms clouds and falls as rain in the mountains which then keeps the dam supplied with water. For free. Gravitational potential energy is stored in the water above the dam. Because the height of the water it will get to the turbines at a higher pressure. This means that people can extract a great deal of energy from it. The water then flows down to the river as normal. There is another way of using the hydroelectric power is to build the station next to a fast flowing river. However using this way may cause a problem which when you do the arrangement the flow of the water cannot be controlled and water cannot be stored. Advantagesà ¢Ã¢â€š ¬Ã‚ ¦ Once the dam is built, energy is almost free. No waste or pollution produced It is more reliable than wind, solar and wave power Water can be stored above the dam Hydroelectric power stations can increase to full power quickly. Electricity can be generated all the time. Disadvantagesà ¢Ã¢â€š ¬Ã‚ ¦ It is very expensive to build Building a large dam will flood a very large area upstream which can cause problems for animals Hard to find a suitable site. Water quality can be effected which have an impact on plants. Hydroelectric power is renewable. It is renewable in the sense that people cannot take away the source of the energy by using them. The sun provides water by evaporation from the sea. No fuel is needed in this generation. Also energy of the tides will not go away if the power is used. Efficiency The equation for hydro electric power is P = Q X H X 0.18 X E The p is for power in watts. The Q is the flow rate in gallons per minute The H is vertical relief measured in feet 0.18 is a unit conversion constant The E is the efficiency of the turbine The micro hydroelectric turbines are an efficiency of 50%. However for the mini hydroelectric applications the efficiency is a bit higher usually around 65%. The Cost The costs of the hydro electric power is everything concerning hydro, the costs are site specific, they will depend on the head available such as the higher the head the smaller the turbine needed to generate the same level of power. The high head machines can be also be connected directly to the generator without the need for the belts. Hydroelectric power is attractive because its cheap for the consumer average price in the PNW is around 4 cents per KWH this is 3 times less than the national average. Low costs to the consumer reflect relatively low operating costs of the Hydro Facility. Most of the cost is in building the dam Operating costs about 0.6 cents per KWH Coal Plant averages around 2.2 cents per KWH which reflects costs of mining, transport and distribution. Energy density in stored important water is high, so one liter of water per second on a turbine generates 720 watts of power. If this power can be continuously generated for 24 hours per day for one month then the total number of KWH per month is then: 720 watts x 24 hours/day x 30 days/month = 518 Kwh/month. Power generating capacity is directly relative to the height the water falls. For a fall of say only 3m, 30 times less electricity would be generated but this is just for a miniscule flow rate of 1 kg/sec. Solar Power- Energy from the Sun Solar power is energy which comes from the sun. People have used sun for drying clothes and foods for thousands of years but only now people have been able to use it for generating power. The sun is about 150 million kilometres away and very powerful. Just a tiny fraction of the suns energy that hits the earth is enough to meet all the power needs many times over. Every minute enough energy gets to the earth to meet the demands for a whole year. Solar power is energy which comes from the sun. This energy is very powerful and hits the earth regardless of whether or not we take advantage of it. Even the tiny percentage of sunlight that touches the earth is plenty to meet the energy and power needs of the entire human population more than 8,500 times over. Energy from the sun is converted into solar power using solar collectors. Solar panels consist of solar cells designed to capture energy from the sun. The solar panels used in heating air and liquid are different from those used to provide electricity. To absorb the highest possible amount of solar energy, solar panels must be pointed at the sun. Energy from the sun can be converted into solar power in two ways. The first way involves the use of solar thermal applications. Solar thermal applications use the suns energy to provide direct heat to air or liquid. Solar thermal panels can be used for both housing and larger scale applications. The second way of obtaining solar power involves the use of photoelectric applications. Photoelectric applications use photovoltaic cells in converting energy from the sun into electricity. Photovoltaic cells are considered low maintenance and well suited to remote applications. They use semiconductors like silicon to convert energy from the sun into electricity. How solar power worksà ¢Ã¢â€š ¬Ã‚ ¦ Solar cells- the Photovoltaic (Photo means light and voltaic means electricity) which convert light directly into electricity, for example in sunny weather you can get enough power to run a 100w light bulb from just one square metre of solar panel. Solar cells provide the energy to run satellites that orbit the earth. Solar water heating- this is where heat from the sun is used to heat water in glass panels. This means people do not use so much gas and electricity to heat water at home. Water is pumped through pipes in the panel, the pipes are painted black, and so they get hotter when the sun shines on them. Solar furnaces- it uses a huge collection of mirrors to concentrate the suns energy into a small space and produce very high temperatures. Solar furnaces are very huge solar cookers. A solar cooker can be used in hot countries to cook food. Solar energy isnt all about generating electricity: For example, photo luminescent products store light energy. Theyre also called self-luminous and are a useful source of emergency lighting in the event of a sudden power outage. The advantages of solar power areà ¢Ã¢â€š ¬Ã‚ ¦ Solar energy is free it needs no fuel and produces no waste or pollution. In sunny countries, solar power can be used where there is no easy way to get electricity. Handy for low-power uses such as solar powered garden lights and battery chargers, or for helping your home energy bills. The disadvantages of solar power areà ¢Ã¢â€š ¬Ã‚ ¦ Doesnt work at night. Very expensive to build solar power stations, although the cost is coming down as technology improves. Can be unreliable unless youre in a very sunny climate. Solar cells are expensive Solar power is renewable. The Sun will keep on shining anyway, so it makes sense to use it. 3 main ways to use it:- Sun heats water in panels on your roof Solar cells photovoltaic cells make electricity from sunlight Solar furnace Solar power isnt much use unless you live somewhere sunny Doesnt cause pollution, doesnt need fuel. Basics of solar power The amount of power generated by solar cells is determined by the amount of light falling on them, which is depending on the weather and time of day. Sometimes there will be too much power, other times these wont be enough. In this case the system battery can be damaged if it was overcharged or over discharged. The smallest system may have only 12 volts of light, but in bigger systems 23o or 110 volts will probably be needed. An invert is used to transform the low voltage Direct Current generated by the solar panel into mains voltage Alternate current. The costs of solar power Solar power is currently selling for between  £3 and 35 per watt of rated power output. A typical panel that you might install on your roof would be rated for between 100 and 300 watts and therefore will cost between about  £400 and around  £1500 or so. A complete solar power system also needs some other components and will have some installation costs and so the total installed cost of a solar system is usually in the range of  £8 10 per watt of rated power. Most home sized systems are rated in the 1000 to 10,000 watt range and therefore cost between about  £8000 and  £100,000 to install. Many states offer refunds and tax savings that can reduce this cost by as much as 50%.These systems will normally generate between about  £300 and  £2500 worth or electricity per year. Solar panels are expected to last between 30 and 50 years and so these systems will likely generate between  £9000 and  £120,000 worth of electricity over their life time. This will be different widely though based on local electricity costs and may well increase greatly in the future if electricity rates rise. Energy efficiency Energy efficiency saves money, where solar energy saves even more money. The efficiency rating of solar panels is fairly low for instance the amount of the suns energy converted into electricity. Depending on the situation it can range from 5% to 15%, although there have been some recent breakthroughs in technology which has increased this to 40%. However it will be some years before this technology becomes money making available in the solar panels we fit to our homes. When calculating how many solar panels you need for your home, you dont need to be too concerned about the efficiency rating of your panel because photovoltaic solar panels are specified by their energy generating capacity. For example, 100 watt panels will output 100 watts of energy under ideal conditions. So if you are looking to produce 1kw per hr of energy you will need 10 x 100 watt panels. Solar panels range in their energy output. normally they range from 30 to 205 watts. If you are DIY then pay special interest in calculating your energy requirements. If you are getting a company to draw up plans for you then they will take care of this calculation. There are three main types of solar photovoltaic cells and these are polycrystalline, mono crystalline and thin film. Each has different efficiency ratings when converting the suns energy into electricity and they all have their advantages and disadvantages. The main difference between them is size and price. The more efficient technologies like mono crystalline panels are more efficient than the other two and so the panels are smaller and take up less space when comparing like for like in energy output but they are more expensive. So before you decide which panels to go for, you need to calculate your energy requirements, establish how much you want to invest and then go and compare the different panels. There are many other aspects that can affect the efficiency of your panels. We find the following to be the most common: how often you clean them, are they infrared, how much sun do they get and how hot do they get. It is a surprise to many people that for most panels their efficiency drops when the temperature starts to go above 25 Deg Celsius. If you want a hot water heater conversion then solar thermal panels are a lot more efficient. In summary, on face value solar energy does not seem very efficient, although it is improving year on year. However, dont get too tied up about the efficiency of the panels, focus more on the output, size and level of investment. Sustainability Solar energy will burn for billions of years; it wont run out any time soon. This is sustainable because it will not reduce in the near future. They use primarily silicon, which is one of the richest materials on earth. But they can also use other things, like metals (copper, silver, gold), and some toxic chemicals (arsenic, cadmium) etc. The sustainability of these materials are recyclable, and it is thought 99% of a solar cell can be recycled. But the production of them does has some toxic site affects, which means we have to balance the clean energy production of the cells with the bad by products of their manufacturing process. Appropriate energy The biggest gains are usually found in lighting. Solar power doesnt have to be used for heating, but it would help. However, electricity is a bad way of heating things, but you can use solar power to heat water. Most houses are not designed for energy efficiency especially old houses. Normally light bulbs waste a lot of energy, thats because they work by getting hot. Its like getting a little light and a lot of heat. Always use low energy lamps. However in low voltage lamps if your solar power is small and you dont have a big inverter, then you will be better off with low voltage lamps. Tidal power Coming and going of the tides gives this form of renewable energy a different advantage over other sources that are not as predictable and reliable, such as wind or solar. The Department of Trade and Industry has stated that almost 10% of the United Kingdoms electricity needs could be met by tidal power. Tides come and go is because it is all to do with the gravitational force of the Moon and Sun, and also the rotation of the Earth. This diagram shows how the gravitational attraction of the moon and sun affect the tides on Earth. The size of this attraction depends on the mass of the object and its distance away. The moon has the greater effect on earth even with having less mass than the sun because it is so much closer. The gravitational force of the moon causes the oceans to swell along an axis pointing directly at the moon. The rotation of the earth causes the rise and fall of the tides. When the sun and moon are in line their gravitational attraction on the earth combine and cause a spring tide. When they are as positioned in the first diagram above, 90 ° from each other, their gravitational attraction each pulls water in different directions, causing a neap tide. The rotational period of the moon is around 4 weeks, while one rotation of the earth takes 24 hours; this results in a tidal cycle of around 12.5 hours. This tidal behaviour is easily predictable and this means that if harnessed, tidal energy could generate power for defined periods of time. These periods of generation could be used to offset generation from other forms such as fossil or nuclear which have environmental consequences. Although this means that supply will never match demand, offsetting harmful forms of generation is an important starting point for renewable energy. Tidal energy is a type of energy that produces electricity and other form of power through the use of water. Tidal energy is the energy that could be obtained from changing sea levels. It is a direct result of tide changing from low to high. The two basic theories on how to convert tides into power are: Is involves in converting the power of the horizontal movement of the water into electricity. Involves producing energy from the rise and drop of water levels. LIKE THIS! Most are at the concept proving stage and have links to universities such as Plymouth, Manchester and Imperial College. Technologies in development include: Use of a shore based oscillating water column, Trapping and compressing air in successive waves to build enough compression to drive a turbine Using pressure differences under wave crests to drive water flows through turbine chambers Floating buoys that use the kinetic energy of the buoys rise and fall to drive a turbine Using the motion of joints in an articulated structure to drive hydraulic rams that power motors. There are different types of turbines that are available for use in a tidal barrage. A bulb turbine is one in which water flows around the turbine. If a repair is required then the water must be stopped which causes a problem and is time consuming with possible loss of generation. When rim turbines are used, the generator is mounted at right angles to the to the turbine blades, making access easier. But this type of turbine is not suitable for pumping and it is difficult to control its performance. The blades of this turbine are connected to a long tube and are leaning at an angle so that the generator is sitting on top of the barrage. The turbines in the barrage can be used to pump extra water into the basin at periods of low demand. This usually works with cheap electricity prices, generally at night when demand is low. The company therefore buys the electricity to pump the extra water in, and then generates power at times of high demand when prices are high so as to make a profit. HOW IT WORKS Step 1: First a place must be chosen for the plant to be built Step 2: Then it must be tested to make sure the waves are big enough to produce enough electricity to make up for the price. Step 3: After this they must build the power plant Step 4: Then they have to test it to make sure it works Step 5: The tidal power plant should do the following: The waves should go into the plant. The pressure of the waves should turn the turbines making electricity. It would cost at least  £15 billion to build a tidal power. However there would be a number of benefits, including protecting a large stretch of coastline against damage from high storm tides and providing an already made road bridge. Although the drastic changes to the currents in the estuary could have a huge affects on the economic and huge number of birds that feed on the mud, so when the tides goes out the birds would have no where to feed. Efficiency of tidal power The benefit of tidal range power is its remarkable efficiency: once constructed, up to 80% of the potential energy of the water captured which can be converted to electricity with no greenhouse emissions. Tidal energy is also attractive from the point of view of energy security which makes uses of resources naturally available on and around the stores. Economics The capital required to start construction of a barrage has been the main awkward block to its deployment. It is not an attractive plan to a saver due to long payback periods. This problem could be solved by government funding or large organisations getting involved with tidal power. In terms of long term costs, once the construction of the barrage is complete, there are very small maintenance and running costs and the turbines only need replacing once around every 30 years. The life of the plant is unclear and for its entire life it will receive free fuel from the tide. The economics of a tidal barrage are very complicated. The optimum design would be the one that produced the most power but also had the smallest barrage possible. Social Impact The building of a tidal barrage can have much social cost on the surrounding area. During the building of the barrage, the amount of traffic and people in the area will increase and will last for a few years. The barrage can be used as a road or rail link, providing a time saving method of crossing the bay or estuary. There is also the possibility of include wind turbines into the barrage to generate extra power. The barrage would affect shipping would have to be made to allow ships to pass through. The biggest disadvantages of tidal barrages are the environmental and ecological affects on the local area. This is very difficult to expect, each site is different and there are not many projects that are available for comparison. The change in water level and possible flooding would affect the plants around the coast, having an impact on the aquatic and shore ecosystems. The quality of the water in the basin or estuary would also be affected, the remains levels would change, affecting the turbidity of the water and therefore affecting the animals that live in it and depend upon it such as fish and birds. Fish would certainly be affected unless condition was made for them to pass through the barrage without being killed by turbines. All these changes would affect the types of birds that are in the area, as they will travel to other areas with more favourable conditions for them. These effects are not all bad, and may allow different species of plant and creature to grow in an area where they are not normally found. But these issues are very fine and need to be independently assessed for the area. Advantage Once tidal power is built it is free. It doesnt produced no green house gases or other waste It needs no fuel It produces electricity Its not expensive to maintain Tides are totally predictable Offshore turbines are not ruinously expensive to build and do not have large environmental impact. Unlike wind and solar power production using the tidal forces is constant and predictable. No Waste produced Sustainability of energy production. Easy and not expensive to maintenance. Has little impact on the environment. Tidal energy turbines are dropped into deep water, so they are not a danger to ships. Tidal power cannot be used up Disadvantages A barrage across an estuary is very expensive to build and effects wide areas Many birds rely on the tide uncovering the mud flat so that they can feed and Fish cant travel Only provides power for around 10 hours a day- when the tide is actually moving in and out There are few suitable sites for tidal barrage. Heavier that wind turbines More expensive than wind turbines. Usually producing power for around 10 hours each day. This is the time frame in which the tide is actually moving in or out. Tidal energy has potential to become a possible option for large scale, base load generation. Tidal Streams are the most attractive method, having reduced environmental and ecological impacts and being cheaper and quicker to be installed. Tidal barrage is where a dam or barrage is built across an estuary or bay that experiences an enough tidal range. This tidal range has to be in overload of 5 metres for the barrage to be possible. The purpose of this dam or barrage is to let water flow through it into the basin as the tide comes in. The barrage has gates in it that allow the water to pass through. The gates are closed when the tide has stopped coming in, trapping the water within the basin creating a hydrostatic head. As the tide moves away out with the barrage, gates in the barrage that contain turbines are opened, the hydrostatic head causes the water to come through these gates, driving the turbines and generating power. Power can be generated in both directions through the barrage but this can affect efficiency and the economics of the project. The structure of a barrage requires a very long national engineering project. The barrage will have environmental and ecological impacts not only during building but will change the area affected forever. Just what these impacts will be is very hard to measure as they are site specific, and each barrage is different. There are different types of turbines that are available for use in a tidal barrage. A bulb turbine is one in which water flows around the turbine. If protection is required then the water must be stopped which causes a problem and is time consuming with possible loss of generation. When rim turbines are used, the generator is mounted at right angles to the to the turbine blades, making access easier. But this type of turbine is not suitable for pumping and it is difficult to control its performance. Bulb Turbine Rim Turbine Tubular Turbine The turbines in the barrage can be used to pump extra water into the basin at stages of low order. This usually matches with cheap electricity prices, generally at night when the order is low. The company therefore buys the electricity to pump the extra water in, and then generates power at times of high claim when prices are high so as to make a profit. This has been used in Hydro Power, and in that context is known as pumped storage. The economical effects of tidal power are when they start building of a barrage has been the main uncertain block to its use. It is not an attractive to a saver due to long payback periods. This problem could be solved by government funding or large organisations getting involved with tidal power. In terms of long term costs, once the building of the barrage is complete, there are very small maintenance and running costs and the turbines only need replacing once around every 30 years. The life of the plant is unclear and for its entire life it will receive free fuel from the tide. The economics of a tidal barrage are very complicated. The best design would be the one that produced the most power but also had the smallest barrage possible. Social impact The building of a tidal barrage can have many social costs on the surrounding area. During building of the barrage, the amount of traffic and people in the area will increase a lot and will last for a number of years. The barrage can be used as a road or rail link, providing a time saving method of crossing the area. There is also the possibility of including wind turbines into the barrage to generate extra power. The barrage would affect shipping and navigation and but would have to be made to allow ships to pass through. Wind power A wind power is the conversion of wind energy into a useful form of energy. Such as people use wind turbine to make electricity, wind mills for mechanical power, wind pumps for pumping water or dra

Simulating Depth Of Field Effects Film Studies Essay

Simulating Depth Of Field Effects Film Studies Essay Depth of field effects: The distance between foreground and background is called depth of field. The depth of field is the distance in front and behind the point of focus. Objects outside of the depth of field are out of focus. In most cases, the depth of field extends one-third of its distance in front of the focal point, and two thirds its distance behind the focal point. Suppose a lens is focused at area, and lens required sharpness at X distance, and the subject is approximately at X distance, now if we move subject sometime near and far away from the camera at same position, than a very minute changes happen to sharpness . So in anywhere not in camera but our eyes also have some zone through which subject is acceptable sharp and that zone itself is the distance between the lens and the subject and that is called depth of field. However, due to limitations in the human eye, subjects that are slightly nearer to the lens and also subjects slightly further from the lens are perceived to be in focus. These below are the factors which affect more and less depth of field effects. More Depth of field effects Less depth of field effects To achieve more depth of field we have to use shorter focal length of lens. To achieve less depth ofd field effects we have to use longer focal length of lens. To achieve more depth of field we have to use small aperture size. To achieve less depth of field we have to use large aperture. Larger acceptable center of confusion (COC). Smaller acceptable center of confusion (COC). Distant plane of critical focus. Close plane of critical focus. Smaller film format. Larger film format. Focus split: Selecting near and far distance which need to be held equally and acceptably in focus and setting the focus distance to suit. Factors affecting Shallow depth of field effects in cameras High contrast lenses have less depth of field effects than the low contrast lens. Consequently, a smaller diameter of center of confusion should be used in depth of field calculation.(eg- 1/2000 instead of 1/1000 ) Lighting which sharply focused details, brightly lighted objects will appear to have less depth of field effects. The use of lens filter in between the lens and the subject, which will reduces maximum definition and make a greater degree of soft focus. As usual but very common, depth of field effects situation arises with uses of wide angle lens at moderate focus distance.( for e.g. 3ft to 12 ft) Object at infinity: This is occur especially when photographed using long focal length lens( more than 55 mm lenses) trend to appear tend to appear soft because of atmospheric elements(like moisture, smoke, dust, haze, smog). There is solution too for such situation that is only either use HAZE filters available in market or using light yellow filters to increase contrast and sharpness in film. This affects when you filming or photographing in any hilly area, mountain area, beaches, waterfall, or any natural area sometime forest too). In case of shutter release Priority: A fast shutter speed used in photography in order to capture fast moving object( e.g. like if you want to take a shot of moving car), whereas a slow shutter speed used to create blur effects on fast moving object( for e.g. a fast moving car in night and you want to capture back light of car as beam using slow shutter speed) , so therefore a fast shutter speed requires a larger aperture size lets say (f1/16or f/11 ) which allow small amount of light to enter the lens hence it extended depth of field effects and in case of slow shutter speed requires small aperture lets say (f2.8, or f2) which allow more light to enter the camera and hence it produce shallow depth of field effects. When aperture is more open than it allows more light to enter the camera and fall on camera CCD, hence to control amount of light we need a more shutter speed to accumulate and to prevent the photograph from over exposed. A telephoto lens gives you a narrow depth of field effects, by moving a lens as close as to the subject and use largest aperture size of camera lens, while to get the large depth of field use Wide angle lens and move your camera and lens as far as possible and use small aperture size. The degree of magnification that the image may be subjected to when shown or projected close or near to the audience sheet to the screen. I mean to say that when Audience close to a cinema screen will be more aware of soft focus than those who are far away from the cinema screen. Focus Bias: This can occur when one subject is in focus and rest is in out of focus like in case of macro photography with small aperture and long focal length for eg a 200 mm lens with aperture value of 2.8 or 2.0. Effects of aperture and the depth of field: The depth of field effects is being controlled by lens aperture value. If you increase the f-number than depth of field effects also increased but decrease the amount of light entering to the camera and when you decrease the f-number than depth of field effects also decreased (it gives shallow depth of field effect). In motion picture its very limited use of it. Generally cinematographer take a single aperture settings for a shot and for another shot they choose another setting as par locality and they adjust exposure settings with the help of light meter device which tells actuall amount of light presents in that area. Aperture settings and exposure settings are changed more frequently in still cameras than motion picture cameras. In photography and cinematography, variation in depth of field effects used to create various kinds of special effects. Camera movement and the depth of field effects: In film making, a person who looks and takes care of responsibility of lens changing, filter changing, point to focus, maintaining depth of field, setting focal length is known as focus-puller. Focus-puller is one of the assistant person in shooting crew members or camera man. A good focus-puller has very adequate and vast knowledge of cinematography. He has to focus and shift focus smoothly in such a manner that audience cant find jerk on them. In film industry most hard job is of focus puller. He has to perform his duty very accurately because suppose if any role given to actor to act on that, and he done that, but while recording focus puller didnt check focal length and filter than actor has to act again. Doing reshot is tough to achieve same expression what he achieved in previous shot. So this was example how much focus puller important to the cinematography. His work is more technical rather than creative. He has to keep in mind all the guidelines given by the director of phot ography during shooting a shot. Cameras depth of field limits The sharpness of depth of field can be increased by decreasing by Center of confusion, but its not as easy to decrease because it also has some disadvantage that is motion blur and diffraction. As we know center of confusion has inversely relation with f-number like a smaller center of confusion need a greater f number, but need a long exposure time. if we increase f-number than diffraction also increases which will soften or soft all the part of image, thus image will no longer be in sharp. The f-number which will overcome from center of confusion is the minimum acceptable sharpness value. If we increase f- number than the sharpness at limited depth of field improved. As we know there is also maximum f-numbers through which sharpness of depth of field in image gets over. The best f-number should be chosen in between of minimum and maximum f-numbers. Depth of field and Macro or close-up: One of the main difficulties with close-up photography is that keeping the image enough in focus. The closer the lens focuses, the less depth of field you have. When using a macro lens at its maximum magnification, depth of field may only extend a fraction of an inch. With floral close-ups, a small aperture is almost always needed, but even so, it is important that the lens focuses on a key focal point in the composition, since not in the entire frame. Depth of field and shooting on bright hot afternoon: While shooting at outdoor especially in day light, the director of photography may wish to reduce amount of light and the depth of field for a close-up shot. For reducing light, a very good filter available called neutral density filter commonly known as ND filter. Suppose the light meter indicating F/22 but we have till f/16, than ND filter play a very important role. This will reduce the amount of light entering to the camera and enable you to shoot on bright sunny day. On other case, if the director of photography wants a close-up shot, and you have to reduce your depth of field, because by reducing depth of field, it will out of focused the background and puts more importance to the subject or highlight the subject. Circle of confusion While shooting the film, the focus puller must be know that which part of scene should be sharp, so therefore we need something to measure the sharpness of image in relative to film limits of the eyes resolution at the time of viewing or at time of projection on screen. For example: if a image is captured through 35 mm film projected at theater, audience must be at distance of 1/3 back from screen. Now we know that eye resolving power is 1 minute of arc. From audience I mean 1/3 back from screen, the smallest size of a dot appearing on a screen which is in perfectly focused or sharp. Now we can easily measures the distance between audience and the screen through any inch tape, from screen the previous sharpen dot which appeared smallest at back now that will be largest dot from the screen, the arc of 1 minute comes up with physical dimension on the screen for the largest dot that the audience previously seen as a smaller sharp point. Figure 1 (need to put a diagram over here) Now the diameter of dot on screen is not actual size of dot, to find actual size of dot we have to calculate diameter of big dot appearing on screen, than we have to divide with enlargement factor needs to bring the size of our 33 mm film up to size of our cinema screen or projected area. This will bring the size of maximum or big dot. When lens is focused at infinity: If any point is focused from the infinity, the distance between plane of focus and the lens become the focal length of the lens. How image size varies at different points behind the camera lens: Figure 2 (need to put a diagram over here) You can see the image is not at extract plane of focus. The image was there somewhere after plane of focus. So in this case size the dot size forming big. Now imagine if the audience sees this dot size sharpen, clearly in focus, than we can easily calculate the amount of sharpness in which part of overall image looks sharp. Near and far points of focus: Figure 3 (need to put a diagram over here) In this case point B creating a sharp image on image plane or plane of focus, while point A creating image after crossing image plane or plane of focus, which means out of focus or blur or less sharpen image. Conclusion: In film plane, both near object and far away object (Lets take Point A and Point B) expanded and become confused to larger dot than the original dot. Hence this is the circle of confusion. Figure 4 (need to put a diagram over here) Thus, a center of confusion (COC) is the diameter of largest dot which is still considers being sharp, focused, and also seen by the audience in Film Theater when it projected on screen. Focus Split: Focus split is selecting the near and far distance which need to be held equally and acceptably in-focus and setting the focus distance to suit. Lets take x as the distance of near object from the camera lens Lets take y as the distance of far away object from the camera lens Than what could be the focus area? Hyper focal Distance: Hyper focal distance is maximum depth of field that starts from infinity to the camera. If a lens is set to hyper focal distance, than the depth of field effects is half of hyper focal distance from infinity. Hyper focal distance is the distance in which lens is focused at infinity, so that the object in background and foreground both will be at sharper focused. Hyper focal distance depends on many factors, some of like Focal length of the camera lens The aperture f- value Diameter of circle of confusion Hyper Focal distance = (FL2) f X COC Where FL means focal length, f-number means aperture size and COC means circle of confusion After knowing hyper focal distance, its easy to calculate near and far point Near point depth of field = H X S H+(S-F) Far point depth of field = H X S H-(S-F) Where H = Hyper focal distance value S = Distance from camera to the subject F = Focal length of camera lens COC = Circle of confusion Focus Bias: Focus bias occurs when one object is in focus and rest is in out of focus (for e.g like in case of macro photography, with larger aperture and longh focal length, i.e f 2.8 with 200 mm focal length) In cinematography, focus plane yet depth of field effects is calculated using the entrance puple position of

boom and bust :: essays research papers

Boom or Bust: Prohibition Coursework Was it bound to fail? A-: Study source A and B. How far do these two accounts agree and prohibition? Source a is dealing with two different sources but both about the subject which is Prohibition. Many of historians have their own opinion about it, but the main question is of these two-account show much do they agree on about Prohibition. Source A is a section of writing that was published in 1973 and was taken from a history book. They clearly state that historians disagree about what was mainly to blame for the introduction of prohibition. By 1917 twenty-three states had already had the ban instated that is stated in the source. Main possible explanations that are stated in the source are the bad influences saloons, wartime concern for preserving grain for food, feeling against the German Americans who were important in brewing and distilling and the influence of the Anti-saloon league t a time when large numbers of men were absent in the armed forces. Even though many people were against prohibition on the other hand there were many people who were for it. This is shown in the source when they state the twenty-three states had already become ‘dry’. The source also states that is was mainly men this is shown when they say that the armed forces numbers were very low. The reason that there were bad feelin g between the Americans and the German Americans were because World War 1 had not taken place to long ago. The source also states that it had created the biggest criminal boom in American history and perhaps in all modern history. â€Å"No earlier law had gone against the daily customs of so many Americans.† This last sentence of the source is very important because it sums everything into one line and I know that the source agreed with the key question because of that sentence. Source B is taken from a history book as well but was published in 1979. This source explains more what happened after prohibition had come into law. The source tells us about the organisations that were supporting the ban on alcohol such as the Women’s Christian Temperance union and the Anti saloon league. Both of these organisations wanted to put an end to alcholism.they did this by putting pressure on congress to ban the use of grain for either brewing or distilling.

Flying Tigers :: American America History

Flying Tigers Flying Tigers is the name of a mercenary group of American pilots that helped defend China and the Burma Road from the bombing of the Japanese during World War II. The name of their planes was Tomahawks, but the Chinese called them Fei Hu for the sharks teeth painted on their planes. Flying Tigers were known as the American Volunteer Group of the Chinese Air Force. The Flying Tigers did not see combat until December 1941 when the Japanese started bombing China. Jim Gordon, the leader of the Flying Tigers, was running short on pilots after the war had started so he began searching for new pilots. Blackie, one of the volunteers, wanted to be part of the Flying Tigers, but Jim didn't want Blackie. So his wife begged Jim to let Blackie into his group. One day during the Japanese bombing, Blackie's plane caught on fire. He jumped out attached to his parachute, but one of the Japanese planes saw him and shot him. Another volunteer, Woody, joined the Flying Tigers, he wanted to prove to Jim Gordon that he was an expert at flying planes. During the first attack, Jim wouldn't let Woody fly, but Woody flew anyway. When he was aiming for a soldier, he noticed that his plane didn't have bullets and was nearly killed. After that happened, Jim thought Woody would one day be a good pilot because he was brave enough to take on three Japanese planes all by himself with no bullets. When the day of December 7, 1941 hit, President Franklin Delano Roosevelt ann ounced on the radio that Pearl Harbor was bombed which was, "A Day of Infamy," and when Jim heard on the radio he was very disappointed. The next day he decided to bomb Japan to help defend his country by himself, but Woody pretended to be the pilot flying the plane because he wanted to help Jim. When they got to Japan, they were aiming for a train full of Japanese soldiers. They started firing at them and when their plane caught fire, Jim and Woody decided to jump out. Then, all of a sudden, Woody pushed Jim out of the plane and flew the plane directly into the train and sacrificed his life to help Jim and his country.

Urban Planners :: essays research papers

URBAN PLANNERS   Ã‚  Ã‚  Ã‚  Ã‚  Urban planners plan for the development of urban and rural areas. Most work for city, county, or other governmental agencies, where they help develop and perform official policy regarding current and future land use. They are concerned with all features of the environment, including the location and design of buildings, transportation systems and with the protection of natural resources, including air and water quality and population density. They report on the best location for houses, stores and parks. Planners also consider social and economic factors that will be affected by land use changes.   Ã‚  Ã‚  Ã‚  Ã‚  Planners generally work in clean, well-lighted offices. However, they may spend much of their time outside the office, attending meetings or hearings, (Sometimes after hours), or inspecting development sites.   Ã‚  Ã‚  Ã‚  Ã‚  A bachelor's degree in planning or a related field is the minimum requirement for professional-level jobs. Some other requirements for most jobs include a master's degree or several years of professional experience or both. However it is possible to get started with only a bachelor's degree, a lot of competition for entry-level jobs and the rising difficulty of the work itself makes a master's degree suitable. Most authorities recommend an undergraduate degree in an area related to planning, such as geography, political science, or architecture followed by a graduate degree in planning. A degree in urban studies, environmental studies, or environmental planning programs requires the same two years of full time study to complete. Local government planning offices often hire college students to work during the summer. Students can learn a lot before they get their first job after they graduate. To become a certified planner, a certain amount of courses must be taken . A few universities have programs under which students may earn master's degrees in planning as well as in an similar field, such as architecture, in about three years of full time study. Planners must be able to think in terms of relationships and visualize the effects of their plans and designs. They should be flexible and able to reconcile different viewpoints and to make constructive policy recommendations. The ability to communicate well, both orally and in writing, is necessary for anyone interested in this field.   Ã‚  Ã‚  Ã‚  Ã‚  Government agency salaries for planners with a bachelor's degree and little or no experience starts at about $2,300 to about $3,000 a month. Planners with a master's degree or one or two years of experience can start at $2,500 to $3,500 or more a month.

Aed 201 Appendix a

Axia College Material Appendix A Final Project Overview and Timeline Final Project Overview Currently, many teachers and paraprofessionals are required to create a professional portfolio as part of their pre-service education. Use Appendix A to help you create a Professional Development Plan, which is a component that can be added to your professional portfolio. In a 2,100- to 2,500-word paper composed in Microsoft © Word, include answers to the following questions: * What are your goals in the next five years? In the next 10 or more years? * What steps are necessary to get you to your goals? What obstacles can you foresee and how will you overcome them? * What is one principle from the INTASC Principles Web site (http://cte. jhu. edu/pds/resources/intasc_principles. htm) that you feel you need to improve the most in order to be effective in the education profession? What existing professional development program(s) could you pursue to address the need to improve in this area? What professional development programs can you enroll in to help you prepare to meet the diverse needs of today's learners? * How will you evaluate your progress? What will help keep you motivated toward achieving those goals? * What professional organizations will you join? Why? What do you expect to gain from membership in these organizations? * What techniques will you use to help you develop leadership skills? Final Project Timeline You should budget your time wisely and work on your project throughout the course. As outlined below, some CheckPoints, assignments, and exercises in the course are designed to assist you in creating your final project. If you complete your course activities and use the feedback provided by your instructor, you will be on the right track to complete your project successfully. * Suggested in Week One: Read Appendix A. Consider how current reforms will affect your 5- and 10-year goals. Review the INTASC Principles at http://cte. jhu. edu/pds/resources/intasc_principles. htm Suggested in Week Two: Make note of anything you’ve come across while interviewing a teaching professional that could be an area of improvement for yourself before or during your first year in the classroom. * Suggested in Week Four: Begin searching for professional educator organizations and/or programs that interest you. * Suggested in Week Five: Begin outlining and writing your final project. * Suggested in Week Eight: Complete and proofread a rough draft of your final project. * Due in Week Nine: Submit your final project.

Brand Analysis For disney cruiseline

The Disney Cruise line is one of the ventures of the Walt Disney company which focuses on providing family entertainment. An analysis of the Disney Cruise line brand indicates that its revenues and market share be taken into consideration. However, Disney does not report the revenues and expenditures of the Cruise line separately. Thus experts’ estimates have to depended upon in order to gauge the worth of the cruise line.According to some analysts:Based on what Disney Cruise Line has reported — about 390,000 passengers a year and an average of $200 in revenue a day per passenger — the business likely grosses more than $312 million a year, or $156 million per ship. (Jackson, 2005) The Disney Cruise line has 2 ships in its fleet with two more to be launched in 2010 and 2011. While each ship can accommodate around 3,508 passengers, the market share of the cruise line is at 1. 8%. (Kwortnik Jr. , 2006) Positioning and Competitive Differentiation PointDisney Cruise l ines position themselves in the market and differentiate on the basis of the value the Cruise line provides rather than service attributes or benefits. According to Anne Riley-Katz: In the nine years that it has operated its current two cruise ships, Disney has set itself apart from other lines by capitalizing on the family niche, a newer segment of a market that traditionally played to honeymooners and retirees. (Riley-Katz, 2007) Disney likes to refer to itself as ‘A leader in the family cruise segment’ (Disney Cruise News, 2009).And the values it highlights are the family experience with fun activities for all age groups. Disney Cruise line boasts of kids’ activities, teenage entertainment activities as well as something to do for adults on their own. It is because of the family focus that Disney cruises are priced higher than other cruise lines and focus on high quality recreational activities aboard the ships. According to the Disney Cruiseline Website: Disn ey Cruise Line offers cruise vacations to be enjoyed by the young and young at heart. (Disney Cruise News, 2009)Thus its point of differentiation lies in the fact that it has special activities and services designed for all age groups heightening family and individual experience. The cruise line’s competitive line of differentiation is its focus on the niche of the family market rather than an adult market exclusively as most cruises are advertised for. Other cruise lines generally are for adults and couples. Unlike most other Cruise lines, Disney does not have a casino on the deck and has areas restricted to adults for activities that are deemed not to be meant for kids.Promotional Messages In a TV commercial aired by the Cruise line available at http://www. youtube. com/watch? v=rHrSX0gHX_8, a child enters an elevator with his mother and his one year old brother and starts relating of his and his family’s experience in a typical child like manner. The high-point of t he commercial is that the child says that his baby brother is a little souvenir from the Disney cruise that they took a year ago. The advertising focuses on Disney creating a magical experience for the entire family which is unforgettable.As in the TV commercial, the child is seen to remember the experience and relate its events as if he had recently been on the trip. This depicts that the Disney Cruise line wants to position its vacations as an unforgettable experience for the parents as well as the children. Moreover, children are more prone to forgetting events but Disney has projected an image where it says that even children remember the experience. Strengths and Weaknesses The strengths of the brand include the huge brand equity that is associated with the parent company. Consumers view Disney as brand oriented towards families and children.Thus Disney comes across as a credible brand that will not malign the minds of children and a brand that parents can trust their children can learn from. The Cruise line with its strong endorsement from the parent company depicts the values that the consumers hold dear in their view of Disney. Thus its main strength lies in the strong brand name. Moreover, the cruise line is priced at premium rates implying high quality services. Further when most cruise lines are focusing on people on a honeymoon or people who have retired Disney has been able to capture the niche of family cruise.the potency of the cruise lines also lies in the fact that being family oriented, the occupancy in the ships is higher than on other cruise lines and that allows for lowering of costs while revenue increases. The weaknesses of the brand are basically its very short fleet of two ships which restricts the number of excursions that Disney can undertake. This is one reason for its market share of merely 1. 8 percent. Along with this is the fact that Disney recently ordered two more ships to be built and given the recent economic downturn and es calating prices, Disney could suffer losses in terms of high prices charged by ship builders.According to estimates the two new ships will cost more than $800 million per ship. (Riley-Katz, 2007). Provided with the fact that Disney’s cruises have been very popular and successful, such a large investment in face of a recession is risky. References Disney Cruise News. (2009). Adults Find Myriad Ways to Escape on Disney Cruise Line. Retrieved March 2009, from Disney Cruise News: http://www. disneycruisenews. com/AssetDetail. aspx? AssetId=8cfde0e4-66fc-4672-ad13-734a0186d8ae Disney Cruise News. (2009). Teenagers Rule on Disney Cruise Line.Retrieved March 2009, from Disney Cruise News Web Site: http://www. disneycruisenews. com/AssetDetail. aspx? AssetId=691d9d37-708c-4052-8a26-4d53b49b1d49 Disney Cruise Website. (2009). Enjoy a $25 Onboard Credit When You Book Online. Retrieved March 1, 2009, from Disney Cruise: http://disneycruise. disney. go. com/dcl/en_US/reserve/specialOffer s/detail? name=SpecialOffer25OnBoardCreditDetailPage Jackson, W. J. (2005, June 13). Disney Cruise Line's Magic luxury ship is spending the summer on the West Coast. Retrieved March 1, 2009, from Disney Wold Trivia: http://www.disneyworldtrivia. com/forums/disney-cruise-line/2619-disney-ship-line-cruise-control. html Kwortnik Jr. , R. J. (2006). Carnival Cruise Lines – Burnishisng the Brand. Retrieved March 1, 2009, from Cornell University Website: http://people. cornell. edu/pages/rjk34/Research/Carnival%20Cruise%20Lines%20Burnishing%20the%20Brand. pdf Riley-Katz, A. (2007, March 12). Yo-Ho, it's major dough: Disney makes, and spends, big money on pricey cruises. Retrieved February 2009, 2009, from The Free Library Website: http://www. thefreelibrary. com/_/print/PrintArticle. aspx? id=161284440