Energy Saving By Using Solar Panels Engineering Essay

Energy Saving By Using Solar Panels Engineering Essay Climate change concerns, coupled with high oil prices, peak oil, and increasing government support, are driving increasing renewable energy legislation, incentives and commercialization. New government spending, regulation and policies helped the industry weather the global financial crisis better than many other sectors. Renewable energy is energy that comes from natural resources such as sunlight, wind, rain, tides, waves and geothermal heat, which are renewable because they are naturally replenished at a constant rate. About 16% of global final energy consumption comes from renewables, with 10% coming from traditional biomass, which is mainly used for heating, and 3.4% from hydroelectricity. New renewables (small hydro, modern biomass, wind, solar, geothermal, and biofuels) accounted for another 3% and are growing very rapidly. The share of renewables in electricity generation is around 19%, with 16% of global electricity coming from hydroelectricity and 3% from new renewables. Si nce its emergence; renewable energy has come a long way. In was not until the 1970s that environmentalists promoted the development of alternative energy both as a replacement for the eventual depletion of oil, as well as for an escape from dependence on oil; it was at that stage that the first wind turbines appeared. On the other hand, solar had always been used for heating and cooling, but solar panels were too costly to build solar farms, until 1980. The reason why have chosen the topic of solar heating systems; solar energy for my dissertation is because among the various renewable energy sources, solar energy is one of the crucial energy sources, if not the most crucial. According to a 2011 projection by the International Energy Agency, solar power generators may produce most of the worlds electricity within 50 years, dramatically reducing the emissions of greenhouse gases that harm the environment. Before doing this report, I have to admit that the knowledge that I had regarding solar energy or solar energy systems was minimal. But since starting working on this report, I think, I have come a long way; yet, I have to admit, there has been done so much research in this field, in the past couple of decade that I would still have to go a long way before I would consider myself a specialist. This report should cater towards any individual who had heard of the solar energy, solar energy systems and how they could benefit from it. T his report also gives a brief insight into, where solar energy system (solar energy) is headed in the future. A far as the structure of my report is concerned, I will be looking into the history of solar energy, the solar energy itself, solar energy collectors solar panels; Furthermore, I would also be looking at the benefits of solar energy systems for us and the consequences, if any. On the other hand, I would also be analysing economic issues related to solar energy systems such as: the cost of heating a house or a building by the means of solar energy contra to contemporary means. Last but not the least I would be summarizing the advantages that I have discussed as well as look at some disadvantages, if there are any. I will sum up the whole report with a conclusion, thanks beforehand. History of solar energy Before we delve into the discussion of why solar energy is so needed in the world today, well first look into what solar energy really is. By definition, solar energy is that beaming light and heat that is generated from the sun. Solar energy has been used by human beings since time immemorial. The radiation that comes from solar energy along with the resultant solar energized resources such as wave power, wind, biomass and hydroelectricity all give an explanation for most of the accessible renewable energy that is present on earth. However, only an infinitesimal portion of the existing solar energy is used. Solar energy has been used by humans for thousands of years. For example, ancient cultures used energy from the sun to keep warm by starting fires with it. Ancient Egyptians built places to live that allowed stored energy from the sun during the day, and a heat release during the night. This kind of architecture: heated homes at night while keeping the temperature low during the day; buildings were designed so that, walls and floors collected solar heat during the day, that was released at night to keep them warm. If you have ever stood in the sun to get warm then you too have utilized solar thermal energy. Egyptians also used the sun as part of their mummification process, using the sun to dry dead bodies. The Egyptians used a form of passive solar power. 3rd Century B.C., Greek soldiers with the help of Archimedes, focused light on a Roman fleet by using mirrors. The Romans were invading a port city that did not have defenses ready for the attack. The mirrors were used to concentrate the energy of the sun, and cause the fleets sails to burn. The Romans retreated and the Greeks were able to prevent the invasion. The Greeks used passive solar power. 100 A.D. a historical writer by the name of Pliny the Younger, built a house in the northern part of Italy that had mica windows in one room. This one particular room demonstrated solar heating in that its mica windows stored heat, and later gave it off. This room was useful because the added heat it generated lessened the amount of wood that had to be burnt, to maintain heat. Roman bath houses had famous south facing windows that heated the rooms. Native Americans also built houses that used passive solar power. Houses were built into the side of cliffs or hills to allow storage of heat during the day, and a release of heat at night. In 1767, the worlds first solar collector was built by Swiss scientist Horace de Saussare. They also kept their homes warm through passive solar energy designs The discovery of photovoltaic happened in 1839 when the French physicist Edmond Becquerel first showed photovoltaic activity. Edmond had found that electrical current in certain materials could be increased when exposed to light. 66 years later, in 1905, we gained an understanding of Edmonds work, when the famous physicist Albert Einstein clearly described the photoelectric effect, the principle on which photovoltaic are based. In 1921 Einstein received the Nobel Prize for his theories on the photoelectric effect. Solar cells of practical use have been available since the mid 1950s when ATT Labs first developed 6% efficient silicon solar cells. By 1960 Hoffman Electronics increased commercial solar cell efficiencies to as much as 14% and today, researchers have developed cells with more than 20% efficiencies. 20% efficient means that out of the total energy that hits the surface of a solar cell; about 20% is converted into usable electricity. The first long-term practical application of PV cells was in satellite systems. In 1958 the Vanguard I, was launched into space. It was the first orbiting vehicle to be powered by solar energy. Photovoltaic silicon solar cells provided the electrical power to the satellite until 1964 when the system was shut down. The solar power system was so successful that PVs have been a part of world-wide satellite space programs ever since. The sun provides endless nonpolluting energy to the satellite power systems and demand for solar cells has risen as a result of the telecommunications revolution and need for satellites. The energy crisis and oil embargos of the 1970s made many nations aware of their dependency on controlled non-renewable energy sources and this fueled exploration of alternative energy sources. This included further research into renewable sources such as solar power, wind power and geothermal power. An economic breakthrough occurred in the 1970s when Dr. Elliot Berman was able to design a less expensive solar cell bringing the price down from $100 per watt to $20 per watt. This huge cost savings opened up a large number of applications that were not considered before because of high costs. These applications included railroads, lighthouses, off-shore oil rigs, buoys, and remote homes. For some countries and many applications, solar energy is now considered a primary energy source, not an alternative. Solar energy Solar energy is the energy derived from the sun through the form of solar radiation. Solar powered electrical generation relies on photovoltaic and heat engines. A partial list of other solar applications includes space heating and cooling through solar architecture, day lighting, solar hot water, solar cooking, and high temperature process heat for industrial purposes. In my report, I would only be looking into a few of the above mentioned solar power harnessing techniques, due to the fact that there is a limitation towards, how much material I can present in my dissertation. Solar cell A solar cell (also called a photovoltaic cell) is an electrical device that converts the energy of light directly into electricity by the photovoltaic effect. It is a form of photoelectric cell (in that its electrical characteristics e.g. current, voltage, or resistance vary when light is incident upon it) which, when exposed to light, can generate and support an electric current without being attached to any external voltage source. Passive solar or active solar Solar technologies are broadly characterized as either passive solar or active solar depending on the way they capture, convert and distribute solar energy. Active solar techniques include the use of photovoltaic panels and solar thermal collectors to harness the energy. Passive solar techniques include orienting a building to the Sun, selecting materials with favorable thermal mass or light dispersing properties, and designing spaces that naturally circulate. The Earth receives 174 petawatts (PW) of incoming solar radiation (insolation) at the upper atmosphere .Approximately 30% is reflected back to space while the rest is absorbed by clouds, oceans and land masses. The spectrum of solar light at the Earths surface is mostly spread across the visible and near-infrared ranges with a small part in the near-ultraviolet. Earths land surface, oceans and atmosphere absorb solar radiation, and this raises their temperature. Warm air containing evaporated water from the oceans rises, causing atmospheric circulation or convection. When the air reaches a high altitude, where the temperature is low, water vapor condenses into clouds, which rain onto the Earths surface, completing the water cycle. The latent heat of water condensation amplifies convection, producing atmospheric phenomena such as wind, cyclones and anti-cyclones. Sunlight absorbed by the oceans and land masses keeps the surface at an average temperature of 14  °C. By photosynthesis green plants convert solar energy into chemical energy, which produces food, wood and the biomass from which fossil fuels are derived. Yearly Solar fluxes Human Energy Consumption Solar 3,850,000 Wind 2,250 EJ Biomass 3,000 EJ Primary energy use (2005) 487 EJ Electricity (2005) 56.7 EJ The total solar energy absorbed by Earths atmosphere, oceans and land masses is approximately 3,850,000 exajoules (EJ) per year. In 2002, this was more energy in one hour than the world used in one year. Photosynthesis captures approximately 3,000 EJ per year in biomass. The amount of solar energy reaching the surface of the planet is so vast that in one year it is about twice as much as will ever be obtained from all of the Earths non-renewable resources of coal, oil, natural gas, and mined uranium combined Solar energy can be harnessed at different levels around the world, mostly depending on distance from the equator. How solar power works Light (photons) striking certain compounds, in particular metals, causes the surface of the material to emit electrons. Light striking other compounds causes the material to accept electrons. It is the combination of these two compounds that can be made use of to cause electrons to flow through a conductor, and thereby create electricity. This phenomenon is called the photo-electric effect. Photovoltaic means sunlight converted into a flow of electrons (electricity). . Passive solar heating In passive solar building design, windows, walls, and floors are made to collect, store, and distribute solar energy in the form of heat in the winter and reject solar heat in the summer. This is called passive solar design or climatic design because, unlike active solar heating systems, it doesnt involve the use of mechanical and electrical devices. The key to designing a passive solar building is to best take advantage of the local climate. Elements to be considered include window placement and glazing type, thermal insulation, thermal mass, and shading. Passive solar design techniques can be applied most easily to new buildings, but existing buildings can be adapted or retrofitted. http://www.iklimnet.com/save/eco_images/five_elements_passive.gif Passive energy gain Passive solar technologies use sunlight without active mechanical systems (as contrasted to active solar). Such technologies convert sunlight into usable heat (water, air, and thermal mass), cause air-movement for ventilating, or future use, with little use of other energy sources. A common example is a solarium on the equator-side of a building. Passive cooling is the use of the same design principles to reduce summer cooling requirements. Some passive systems use a small amount of conventional energy to control dampers, shutters, night insulation, and other devices that enhance solar energy collection, storage, and use, and reduce undesirable heat transfer. Passive solar technologies include direct and indirect solar gain for space heating, solar water heating systems based on the thermo siphon or geyser pump, use of thermal mass and phase-change materials for slowing indoor air temperature swings, solar cookers, the solar chimney for enhancing natural ventilation, and earth sheltering. More widely, passive solar technologies include the solar furnace and solar forge, but these typically require some external energy for aligning their concentrating mirrors or receivers, and historically have not proven to be practical or cost effective for widespread use. Low-grade energy needs, such as space and water heating, have proven, over time, to be better applications for passive use of solar energy. Pragmatic approach to a productive passive solar energy Many detached suburban houses can achieve reductions in heating expense without obvious changes to their appearance, comfort or usability. This is done using good siting and window positioning, small amounts of thermal mass, with good-but-conventional insulation, weatherization, and an occasional supplementary heat source, such as a central radiator connected to a (solar) water heater. Sunrays may fall on a wall during the daytime and raise the temperature of its thermal mass. This will then radiate heat into the building in the evening. This can be a problem in the summer, especially on western walls in areas with high degree day cooling requirements. External shading, or a radiant barrier plus air gap, may be used to reduce undesirable summer solar gain. Active solar heating systems Active solar technologies are employed to convert solar energy into another more useful form of energy. This would normally be a conversion to heat or electrical energy. Inside a building this energy would be used for heating, cooling, or off-setting other energy use or costs. Active solar uses electrical or mechanical equipment for this conversion. Solar energy collection and utilization systems that do not use external energy, such as a solar chimney, are classified as passive solar technologies. Passive solar relies on the inherent thermo-dynamic properties of the system or materials to operate. They do not need external energy sources. https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhcs9d3FUKO0lvb9i3AL_e96M4W-zZMJ1EONNeC0KuyM3YBFQdtM02LMYIyGYKWAnZAuFG8bkJSECEmyNH-p-I_HOZVgdYg43sZd1OdnRt6rwToEcp4mZXsxAnwTP9XfTf_ioOd6IR4HGtz/s1600/active-solar-heating.jpg Solar hot water systems, except those based on the thermo siphon, use pumps or fans to circulate fluid (often a mixture of water and glycol to prevent freezing during winter periods) or air, through solar collectors, and are therefore classified under active solar technology. The basic benefit of active systems is that controls (usually electrical) can be used to maximize their effectiveness. For example a passive solar thermal array which does not rely on pumps and sensors will only start circulating when a certain amount of internal energy has built up in the system. Using sensors and pumps, a relatively small amount of energy (i.e. that used to power a pump and controller) can harvest a far larger amount of available thermal energy by switching on as soon as a useful temperature differential becomes present. Controls also allow a greater variety of choices for utilizing the energy that becomes available. For example a solar thermal array could heat a swimming pool on a relatively cool morning where heating a domestic hot water cylinder was impractical due to the different stored water temperatures. Later in the day as the temperature rises the controls could be used to switch the solar heated water over to the cylinder instead. The downside to Active Solar systems is that the external power sources can fail (probably rendering them useless), and the controls need maintenance. How to buy solar panels solar water heating Shower Solar water heating can meet about a third of your hot water needs, research conducted by a UK research magazine. A solar water heating system (also known as solar thermal system) uses panels fitted to your roof to heat water for use around the home. A typical solar hot water system is able to meet around a third of a households hot water needs a saving of  £55 to  £80 on your annual water-heating bills, based on a three-bedroom semi-detached house. Householders installing solar water heating systems can get  £300 through the governments Renewable Heat Incentive Premium Payment scheme. Choosing a solar water heating system When choosing a solar water heating system, youll need to consider four major factors: your average hot water use the area of south-facing roof available your existing water heating system your budget. Youll need roughly one square meter of collector area per person in the household. Each metre of panel area will need between 30 and 60 litres of water tank volume. If you use a less efficient collector (such as flat-plate solar water heating panels), youll need to cover a larger area than if you use a more efficient collector (such as evacuated tubes). Youll also need to select system components (such as a hot water cylinder, controls and pipe work) and choose the location for your solar panels, considering shade, pipe runs, roof pitch and future access. Solar water heating installation There are plenty of solar panel installers out there, so I recommend that you always collect a range of quotes to compare. Cost effectiveness of solar water heating systems In my opinion developing common industry standards and offering public incentives is important. He emphasizes that creating public awareness programs is the key to having success in this industry, including a cleaner environment and more jobs as a consequence. It is clear that installing the application is easy for households since the technology is less complicated and cheaper than PV. According to The Solar Guide, the payback period for an investment in a solar water heating system is 3 to 5 years, although it may vary a lot in different countries due to national standards and differences in manufacturing quality. The return of investment depends on the system and the current fuel source that is being used to heat the water. It makes more sense to install a combi-system (hot water+space heating) whereby a 12-20 sq-m would completely cover a households water heating demand and a substantial part of its space heating demand in spring and in autumn. http://upload.wikimedia.org/wikipedia/commons/thumb/f/f7/SolarTrackerRoofView300W200H.jpg/220px-SolarTrackerRoofView300W200H.jpg Solar trackers may be driven by active or passive solar technology Most solar collectors are fixed in their array position mounting, but can have a higher performance if they track the path of the sun through the sky (however it is unusual for thermal collectors to be mounted in this way). Solar trackers, used to orient solar arrays may be driven by either passive or active technology, and can have a significant gain in energy yield over the course of a year when compared to a fixed array. Again passive solar tracking would rely on the inherent thermo-dynamic properties of the materials used in the system rather than an external power source to generate its tracking movement. Active Solar Tracking would utilize sensors and motors track the path of the sun across the sky. This action can be caused by geographical and time data being programmed into the controls. However, some systems actually track the brightest point in the sky using light sensors, and manufacturers claim this can add a significant extra yield over and above geographical tracking. How does Solar Thermal work? The basic mechanism of solar thermal energy is to collect the solar radiation and transfer the heat directly or indirectly to its final destination via a heat transfer medium usually a fluid. The most commonly used applications are Domestic Hot water (DHW), Combined DHW and Space Heating, District Heating, Solar Cooling and Air-Conditioning. High Temperature Solar Thermal Electricity Generation is also among solar thermal applications. (e.g. solar tower and parabolic through applications). The key component of the solar thermal systems is the collectors which can be divided into two groups: Unglazed collectors have been used in the industry for a long time, mainly for heating open-air swimming pools. There is no heat exchanger in the system, and the water is flowing directly through long thin tubes. It is cheap and easy to install. Due to the simplicity of unglazed collectors, they cannot fulfill the needs for delivering full-time energy. Unglazed collectors are mainly used in the USA and in Australia. Glazed collectors are much more efficient in supplying continuous heating and achieving higher temperatures than unglazed ones. Glazed collectors are usually rectangular boxes covered by glass, containing little pipes and tubes and a heat absorbing material inside. There are different types of collectors for different means of use. Glazed collectors are commonly used in China, Europe and the Middle East. Solar thermal collector A solar thermal collector is a solar collector designed to collect heat by absorbing sunlight. The term is applied to solar hot water panels, but may also be used to denote more complex installations such as solar parabolic, solar trough and solar towers or simpler installations such as solar air heat. The more complex collectors are generally used in solar power plants where solar heat is used to generate electricity by heating water to produce steam which drives a turbine connected to an electrical generator. The simpler collectors are typically used for supplemental space heating in residential and commercial buildings. A collector is a device for converting the energy in solar radiation into a more usable or storable form. The energy in sunlight is in the form of electromagnetic radiation from the infrared (long) to the ultraviolet (short) wavelengths. The solar energy striking the Earths surface depends on weather conditions, as well as location and orientation of the surface, b ut overall, it averages about 1,000 watts per square meter under clear skies with the surface directly perpendicular to the suns rays. A solar collector works to convert and concentrate solar energy into a more usable form. For example, a thermal collector may use a parabolic array of mirrors to focus, direct, and reflect the light of the sun to a smaller point where the heat can be used to drive some sort of turbine engine by heating the driving fluid. Another type of collector may use a flat panel array of solar photovoltaic cells to convert solar energy directly into electricity. Some metals exhibit a photoelectric property whereby when the metal is exposed to light, it causes electrons to be emitted. These metals may be arranged in a valence-covalence band configuration which generates the actual voltage within the array. Types of solar collectors for heat Solar collectors fall into two general categories: non-concentrating and concentrating. In the non-concentrating type, the collector area (i.e., the area that intercepts the solar radiation) is the same as the absorber area (i.e., the area absorbing the radiation). In these types the whole solar panel absorbs the light. Flat-plate and evacuated-tube solar collectors are used to collect heat for space heating, domestic hot water or cooling with an absorption chiller. Types of solar collectors for electricity generation Parabolic troughs, dishes and towers described in this section are used almost exclusively in solar power generating stations or for research purposes. Although simple, these solar concentrators are quite far from the theoretical maximum concentration. For example, the parabolic trough concentration is about 1/3 of the theoretical maximum for the same acceptance angle, that is, for the same overall tolerances for the system. Approaching the theoretical maximum may be achieved by using more elaborate concentrators based on non-imaging optics. Parabolic trough http://upload.wikimedia.org/wikipedia/commons/thumb/b/b5/Parabolic_trough.svg/250px-Parabolic_trough.svg.png Parabolic torough This type of collector is generally used in solar power plants. A trough-shaped parabolic reflector is used to concentrate sunlight on an insulated tube (Dewar tube) or heat pipe, placed at the focal point, containing coolant which transfers heat from the collectors to the boilers in the power station. Parabolic dish http://upload.wikimedia.org/wikipedia/commons/thumb/1/12/Parabolic-dish.jpg/220px-Parabolic-dish.jpg http://bits.wikimedia.org/static-1.21wmf3/skins/common/images/magnify-clip.png Solar Parabolic dish It is the most powerful type of collector. One or more parabolic dishes concentrate solar energy at a single focal point, -similar to a reflecting telescope which focuses starlight, or to a dish antenna used to focus radio waves. This geometry may be used in solar furnaces and solar power plants. There are two key phenomena to understand in order to comprehend the design of a parabolic dish. One is that the shape of a parabola is defined such that incoming rays which are parallel to the dishs axis will be reflected toward the focus, no matter where on the dish they arrive. The second key is that the light rays from the sun arriving at the Earths surface are almost completely parallel. So if the dish can be aligned with its axis pointing at the sun, almost all of the incoming radiation will be reflected towards the focal point of the dish-most losses are due to imperfections in the parabolic shape and imperfect reflection. Losses due to atmosphere between the dish and its focal point are minimal, as the dish is generally designed specifically to be small enough that this factor is insignificant on a clear, sunny day. Compare this though with some other designs, and you will see that this could be an important factor, and if the local weather is hazy, or foggy, it may reduce the efficiency of a parabolic dish significantly. In dish-stirling power plant designs, a Stirling engine coupled to a dynamo is placed at the focus of the dish, which absorbs the heat of the incident solar radiation, and converts it into electricity. (Solar) Power tower A power tower is a large tower surrounded by tracking mirrors called heliostats. These mirrors align themselves and focus sunlight on the receiver at the top of tower, collected heat is transferred to a power station below. Advantages Very high temperatures reached. High temperatures are suitable for electricity generation using conventional methods like steam turbine or some direct high temperature chemical reaction. Good efficiency. By concentrating sunlight current systems can get better efficiency than simple solar cells. A larger area can be covered by using relatively inexpensive mirrors rather than using expensive. Concentrated light can be redirected to a suitable location via. For example illuminating buildings. Heat storage for power production during cloudy and overnight conditions can be accomplished, often by underground tank storage of heated fluids. Molten salts have been used to good effect. Disadvantages Concentrating systems require sun tracking to maintain Sunlight focus at the collector. Inability to provide power in diffused light conditions. Solar Cells are able to provide some output even if the sky becomes a little bit cloudy, but power output from concentrating systems drop drastically in cloudy conditions as diffused light cannot be concentrated passively. Solar panel A solar panel (also solar module, photovoltaic module or photovoltaic panel) is a packaged, connected assembly of photovoltaic cells. The solar panel can be used as a component of a larger photovoltaic system to generate and supply electricity in commercial and residential applications. Each panel is rated by its DC output power under standard test conditions, and typically ranges from 100 to 320 watts. The efficiency of a panel determines the area of a panel given the same rated output an 8% efficient 230 watt panel will have twice the area of a 16% efficient 230 watt panel. Because a single solar panel can produce only a limited amount of power, most installations contain multiple panels. A photovoltaic system typically includes an array of solar panels, an inverter, and sometimes a battery and or solar tracker and interconnection wiring. Theory and construction Solar panels use light energy (photons) from the sun to generate electricity through the photovoltaic effect. The majority of modules use wafer-based crystalline silicon cells or thin-film cells based on cadmium telluride or silicon. The structural (load carrying) member of a module can either be the top layer or the back layer. Cells must also be protected from mechanical damage and moisture. Most solar panels are rigid, but semi-flexible ones are available, based on thin-film cells. Electrical connections are made in series to achieve a desired output voltage and/or in parallel to provide a desired current capability. The conducting wires that take the current off the panels may contain silver, copper or other non-magnetic conductive transition metals. The cells must be connected electrically to one another and to the rest of the system. Externally, popular terrestrial usage photovoltaic panels use MC3 (older) or MC4 connectors to facilitate easy weatherproof connections to the rest of the system. Bypass diodes may be incorporated or used externally, in case of partial panel shading, to

Twelfth Night Essay: Exploration of Love :: Twelfth Night essays

Exploration of Love in Twelfth Night      Ã‚  Ã‚   In the play "Twelfth Night," Shakespeare explores and illustrates the emotion of love with precise detail. According to "Webster's New World Dictionary," love is defined as "a strong affection or liking for someone." Throughout the play Shakespeare examines three different types of love: true love, self love and friendship.   Ã‚  Ã‚  Ã‚   "Twelfth Night" consists of many love triangles, however many of the characters who are tangled up in the web of love are blind to see that their emotions and feelings toward other characters are untrue. They are being deceived by themselves and/or the others around them. There are certain instances in the play where the emotion of love is true, and the two people involved feel very strongly toward one another. Viola's love for Orsino is a great example of true love. Although she is pretending to be a man and is virtually unknown in Illyria, she hopes to win the Duke's heart. In act 1, scene 4, Viola let's out her true feelings for Cesario, "yet a barful strife! Whoe'er I woo, myself would be his wife (1)." That statement becomes true when Viola reveals her true identity. Viola and Orsino had a very good friendship, and making the switch to husband and wife was easy. Viola was caught up in another true love scenario, only this time she was on the receiving end, and t hings didn't work out so smoothly. During her attempts to court Olivia for Orsino, Olivia grew to love Cesario. Viola was now caught in a terrible situation and there was only one way out, but that would jeopardize her chances with Orsino. It's amazing that Olivia could fall for a woman dressed as a man, but because Viola knew what women like to hear, her words won Olivia's heart. The next case of true love is on a less intimate and romantic scale, and more family oriented. Viola and Sebastian's love for one another is a bond felt by all siblings. Through their times of sorrow and mourning for each of their apparent deaths they still loved each other. They believed deep down that maybe someway or by some miracle that each of them was still alive and well.   Ã‚  Ã‚  Ã‚   Many people, even in today's society, love themselves more then anything else. "Twelfth Night" addresses the issue of self love and how it affects peoples lives.

Looking Deathworthy Essay

Researchers Jennifer L. Eberhardt, Paul G. Davis Valerie J. Purdie-Vaughns, and Sheri Lynn Johnson studied whether being stereotypically black influences the probability of receiving the death penalty. Sociologist have previously proven that people quickly apply racial stereotypes to blacks who have the stereotypically appearance of a black person. This racial profile effects how people judge an individual and this judgment may very well influence how one is treated by others. This study is important because it shows how racial stereotypes can affect the sentence given to a defendant guilty of murder. The relationship of the different sentences of black on black murders vs. black on white murders is also slightly exposed in this study. For science, this shows a new perspective of how modern society views and profiles African-American men. These stereotypes have and influence on how people treat one another, in this case African-American murder defendants, which is changing society as a whole. Judgment plays a major role in how we interact with one another. The researchers had a very basic research design. There topic was if being stereotypically black influences the possibility of being sentenced with the death penalty. They defined there problem by stating how previous researchers have found a correlation between racial profiling and how people judge others. Researchers have also found that murders of white victims are more likely than murderers of black victims to be sentenced to death. The article Looking Deathworthy by the researchers that conducted this experiment, states that the researchers reviewed plenty of previous studies, theories, and cases. They conducted the experiment in two methods. The first method they showed pictures of 44 black males convicted of murdering white victims in Pennsylvania and Philadelphia during 1979 and 1999, and showing their pictures to raters. The raters where Stanford University undergraduates who were not told the men in the pictures where convicted murderers. They simply rated the men according to how stereotypically black they looked. The researchers found that the defendants who appeared to be more stereotypically black than the others were more likely to receive a death sentence. In the second method, they used the same databases and procedures to see if the same result would be obtained in the experiment if the victims were black. They found that the perceived stereo typicality of black defendants convicted of murdering black victims did not predict a death sentence. There were a couple of limitations made by these researchers that might have effect the outcome of the research. The researchers only used black defendants from the Pennsylvania and Philadelphia area. These changes make the research only correct for that area at that particular time. They should have broadened their case studies to all the states in the U. S. the researchers also only used raters from Standford University. There is a greater chance the people from the same area and same age group judge individuals with the same mentality. They should have used different age groups and people from different backgrounds as raters. T would have made the study more valid. I feel that this was an excellent theory to experiment and I agree that it is true. Capital punishment does give harder sentences for murder defendants who look stereotypically black. However, the study should have been broader. The researchers had variables that if they removed, would have allowed their findings to be more valid.

Harry Potter and the Sorcerer essays

Harry Potter and the Sorcerer essays Harry Potter and the Sorcerers Stone I have to admit that I was rather upset to find out that we had to read this book. I have never been interested in science fiction/fantasy stories before, and I never understood what all the hype about Harry Potter was all about. As I reluctantly began to read the story, I soon found myself tearing through the pages eager to find out what happened next. As the story began, I was reminded of Cinderella. Just as Cinderellas stepmother and stepsisters treated her unfairly, Harry too grew up in a home unwanted and unloved. Both Cinderella and Harry watched their sibling(s) being doted on and spoiled with lavish gifts as they were forced to accept hand-me-downs, perform all the chores, and receive only the bare necessities needed to survive. After both grew up not knowing any other way of life, they were both magically rescued and taken away to enjoy all the riches that their families would envy. I could identify with Harrys character on many levels. I know what its like first hand to go somewhere where everything is foreign and new. Two years ago, I traveled with a friend of mine to Italy. Unable to speak the language and unaccustomed to the culture, like Harry during his first few days at school, I too had extreme difficulty finding my way around and trying to blend in. People stared at me like I was some strange creature when I didnt understand what they were saying to me. Simple things like dining out in a restaurant were difficult for me to do. The money was different, the time of day was different, I had all the wrong clothes, and the people and their culture were entirely different to what I have been accustomed to. I could only imagine the culture shock that Harry encountered when he left the Muggle world. I also found myself recounting my first days at a public high school after having attended a small, private C ...

What’s a Good ACT Score for 2018

What’s a Good ACT Score for 2018 SAT / ACT Prep Online Guides and Tips Planning to take the ACT in the 2017-18 school year? In addition to studying for the test, you'll need to know what score to aim for. What is a good ACT score for 2018? What's a good score for each section? Has the definition of a good ACT score changed over time? We’ll start by looking at what are considered good ACT scores for 2018 using the average score and percentiles. After, we'll go over how to set an ACT goal score and then examine historical ACT score data to see whether the definition of good ACT scores has changed in recent years. What Is a Good ACT Score for 2018 Overall? First off, what is a good ACT score for 2018, broadly speaking? We can answer this question by looking at the average ACT score for 2018and the national ACT score percentilesfor 2018.Both averages and percentiles can be used to see how your ACT score stacks up against those of other test takers. This data is important to know since colleges regularly compare applicants' test scores during the admissions process. So what are percentiles exactly? In short, percentiles tell you what percentage of test takers you scored higher than, either on the test as a whole or a particular section. Thus, the higher your ACT percentile is, the better your ACT performance will be (compared with other test takers). But before we can answer the question, "What is a good ACT score for 2018?" we need to review how the ACT scoring system actually works. The ACT uses a scoring scale of 1-36, both overall and for each of its four sections: English, Math, Reading, and Science. (There’s also an optional Writing section, whose score- which uses a scale of 2-12- doesnot factor into your composite ACT score.) Now, let’s look at some data: according to ACT, Inc., the average ACT score for 2018 is 20.9.In general, any score above average can be considered "good," any score below average can be considered "poor," and any score at or right around average can be considered "OK." The higher your score is above the average, the better your score (and the higher your percentile) will be. Similarly, the lower your score is below the average, the worse your score will look to schools. Here are the ACT score percentiles for 2018 and what they say about your performance: Percentile* English Math Reading Science Composite 90th (excellent) 29-30 28 31 27-28 28 75th (good) 24 24 25 24 24 50th (OK) 20 19 20 20 20 25th (poor) 14-15 16 16 16-17 16 10th (very poor) 11 14 13 13 13 Source: ACT.org *For percentiles not reported in official data, estimated ACT scores/ranges have been given. In this chart, we can see that to get a good ACT score for 2018, you’ll typically need to aim for at least the 75th percentile, or 24-25, on each section. If you’re aiming for a particularly high ACT score in the top 10 percent, you’ll have to get at least 28-30 on each section (coming out to a composite score of 28).Interestingly, this total score is a whole 8 points below 36, a perfect ACT score. In other words, to get an excellent ACT score, you don’t even need to break 30! On the opposite side are the poor scores, which are anything (significantly) below average.For example, a 10th percentile ACT composite score is 13, meaning that any score in the range of 1-13 is a pretty low score. Therefore, you’ll definitely want to do better than this on the test before you send ACT scores to schools. But what does all of this data mean for you specifically? Keep reading to learn how you can use this information to set a personal ACT goal score for 2018. What Is a Good 2018 ACT Score for You? While all of these 2018 ACT score percentiles and averages are helpful to know, they don’t tell you what a good ACT score for you is in particular. Ultimately, what's more important than hitting a certain percentile is getting an ACT score that's high enough to get you accepted to your chosen schools. This â€Å"goal† score can vary depending on the schools you’re applying to.For example, for someone applying to Caltech, a good ACT score would be something close to a perfect 36. However, for someone applying to Mississippi State, a good ACT score would be a lot lower, around 27. As you can see, your ACT goal score isn't always going to be the same as someone else’s- this is OK! Not everyone applies to the same schools, so there’s really no point in comparing your goal score with those of your friends or classmates. All you need to know is that this score is your ideal score. If you can hit it, you significantly raise your chances of getting accepted to your top schools.But how do you find your ACT goal score? How to Set an ACT Goal Score for 2018 Setting an ACT goal score is a pretty simple process. Follow the three steps below to get started! Step 1: Make a Chart A chart helps you easily visualize what kinds of ACT scores your schools look for in applicants. Write the names of the schools you’re applying to in the leftmost column. Then, write the headings â€Å"25th Percentile ACT Score† and â€Å"75th Percentile ACT Score† horizontally across the top. (We'll explain more about what these headings mean in the next step.) Here's an example for reference: School 25th Percentile ACT Score 75th Percentile ACT Score Northeastern Boston College NYU Brandeis Brandeis University (John Phelan/Wikimedia) Step 2: Find ACT Score Info for Your Schools Now, it’s time to start filling out your chart. The easiest way to find ACT score info for your schools is to search â€Å"[School Name] PrepScholar† on Google. Click the link to your school’s â€Å"Admission Requirements† page in our database. Once on this page, scroll down until you get to your school's ACT score info. Here’s an example of an Admission Requirements page for Northeastern University: In the ACT score info section, look for the 25th and 75th percentile ACT scores for your school. These are located directly under the "school competitiveness" graphic. In the screenshot above, you can see that Northeastern's 25th and 75th percentile scores are 31 and 34, respectively. But why these percentiles? What do they mean? The 25th and 75th percentiles for a school are the middle 50 percent, or average range, of ACT scores for admitted applicants.These percentiles tell you precisely what kinds of scores successful students have had when applying to your school. If you can’t find your school in our database, search online for â€Å"[School Name] 25th 75th percentile ACT† or â€Å"[School Name] average ACT score.† Try to look for links to your school’s official website so you can verify that the info you find is accurate. Let’s take a look at our sample chart again, now with each school's ACT scores filled out: School 25th Percentile ACT Score 75th Percentile ACT Score Northeastern 31 34 Boston College 30 33 NYU 28 32 Brandeis 29 33 Step 3: Find Your Goal Score Now that you’ve got all of the info you need, it’s time to use your chart to find your ACT goal score. Look for the highest 75th percentile score in your chart. In our example, the highest score is 34 (for Northeastern). This score will be your goal score, as it’s the one most likely to get you accepted to all of the schools in your chart. Since your composite ACT score is the average of your four section scores, you can use your goal score to estimate what score to aim for on each section.For example, if your goal score is 28, you'll know to roughly aim for 28 on the four sections, too (so that the average of them, or your composite score, comes out to 28). That being said, if you're stronger at certain sections or topics, you might want to aim for higher scores on those sections and lower scores on the others. For instance, if your goal score is 30 and you're really good at math but not so great at reading, you could aim forsomething like 32 on Math and 28 on Reading (instead of 30 on both sections). In this case, you'll still be able to hit your goal score- you're just using a different combination of section scores to get there. How Have Good ACT Scores Changed Over Time? We now know what a good ACT score for 2018 is, both overall and for you specifically. But how has the definition of a good ACT score changed over the years? Has it changed dramatically, or has it generally stayed the same? To answer these questions, let’s look at some data. The following table shows the average ACT scores for the past decade: Average ACT Scores 2007-2017 Year English Math Reading Science Composite 2007 20.7 21.0 21.5 21.0 21.2 2008 20.6 21.0 21.4 20.8 21.1 2009 20.6 21.0 21.4 20.9 21.1 2010 20.5 21.0 21.3 20.9 21.0 2011 20.6 21.1 21.3 20.9 21.1 2012 20.5 21.1 21.3 20.9 21.1 2013 20.2 20.9 21.1 20.7 20.9 2014 20.3 20.9 21.3 20.8 21.0 2015 20.4 20.8 21.4 20.9 21.0 2016 20.1 20.6 21.3 20.8 20.8 2017 20.3 20.7 21.4 21.0 21.0 Sources: ACT 2017 National Profile Report, ACT 2012 National Profile Report, ACT 2011 National Profile Report As this chart indicates, average ACT scores clearly haven’t shifted much over time. The biggest change in points in any column is just 0.6 points, which isn’t a huge difference in the grand scheme of ACT scoring.Thus, we can say that ACT averages have stayed fairly consistent over time and are likely to continue to do so based on these trends. What about percentiles, though? Above, we used percentiles to show what good, OK, and poor ACT scores look like. But have the scores associated with these percentiles changed over time? Below are ACT composite scores and their corresponding 25th, 50th, and 75th percentiles for the past decade: ACT Score Percentiles 2007-2017 Year 75th Percentile 50th Percentile 25th Percentile 2007 25 21 17 2008 25 21 17 2009 25 21 17 2010 25 21 17 2011 25 21 17 2012 25 21 17 2013 25 21 17 2014 25 21 17 2015 25 21 17 2016 25 20 16 2017 25 20 17 Like the first chart, we can see that changes over the years are extremely minimal. The 75th percentile score stays at 25 the entire decade, while the 50th and 25th percentile scores exhibit only a nominal change of 1 point starting in 2016. It's safe to say, then, that the definition of a â€Å"good† (or an â€Å"OK† or â€Å"poor†) ACT score has stayed relatively stable over the past decade. The fact that ACT scores and their percentiles don't change much is helpful to know if you want to compare a more recent ACT score with an older one. For example, if you wanted to compare your 2017 ACT score with your older sister’s 2012 ACT score, you can easily do this using percentiles- without having to takeinto account test years or dates. Recap: So What’s a Good ACT Score for 2018? There are a couple of ways to determine what good ACT scores for 2018 are. One way is to look at averages and percentiles. According to the most recent data, the average composite ACT score is 20.9. In general, any score at or around average is OK, any score higher than average(75th percentile)is good, and any score lower than average(25th percentile) is poor. Because the definition of a good ACT score hasn’t changed much in the past decade, you can easily compare scores across the years without having to adjust for test dates or testing years. In the end, though, a good 2018 ACT score for you depends not on averages or percentiles but on the schools you wish to attend. This ideal score is your ACT goal score, and it’s the one most likely to get you into all of the schools you’re applying to.Hit this score and you'll give yourself your best chance at getting into the college of your dreams! What’s Next? Still got questions about what constitutes a good ACT score? Check out our in-depth guide to good, excellent, and poor ACT scores. Need help getting started on your ACT prep? Follow our guide to developing a foolproof ACT study plan, and get expert tips on the best ACT test dates. Looking for ACT tips to improve your score and help you hit your goal?Our guide offers a compilation of the best ACT tricks and advice out there! Want to improve your ACT score by 4 points? Check out our best-in-class online ACT prep program. We guarantee your money back if you don't improve your ACT score by 4 points or more. Our program is entirely online, and it customizes your prep program to your strengths and weaknesses. We also have expert instructors who can grade every one of your practice ACT essays, giving feedback on how to improve your score. Check out our 5-day free trial:

Mechanical cavopulmonary assist device cage for Fontan patients Research Paper

Mechanical cavopulmonary assist device cage for Fontan patients - Research Paper Example Smaller size of the filaments limits the structural support ability of the protective cage while large sizes of the filaments decreases the hydrodynamic properties of the design while increasing the pressure. The size of the filament thickness is however subject to change based on computational test results. The number of filaments is proposed to be five, not the same as the number of impeller blades, in order to shun resonance and vibration of the system. The protective cage offers protection to the vessel from the rotating components through its radial arrangements of the filaments. The elliptical design of the protective cage of filaments not only presents hydrodynamic characteristics but also provides space efficiency. The angle designs of the blades helps in space conservation given that a number of the blades can be fitted within the pump for maximum functionality. This helps in minimizing the size of the pump to ensure it properly fits within the blood vessel. The pump is characterised with diffuser blades, which are located on the protective filament cage. A shift in the flow directionality aids the diffuser blades to convert the rotational force produced by the impellor to potential energy. A motor-magnetic bearing suspension is used to induce the pump rotation. The proposed design will aim to achieve this through the levitation and rotation of the impellor within the protective filament cage (Throckmorton et al., 2010). The protective cage of filaments is designed with five elliptically shaped filaments. The proposal aims at modifying the design to serve both protective and design functions at the same time. The shape of the protective cage filaments serves significant role in stabilizing the impeller blades radially and axially in addition to acting as a barrier in the protection of the vessel from the rotating impeller blades. The unique elliptical design shape of the filaments plays a vital role in maximizing energy production from impeller while

Ethics and Governance Case Study Example | Topics and Well Written Essays - 500 words

Ethics and Governance - Case Study Example The cause for Friedman’s statement is probably due to the birth of ‘Ethical business’, this is where companies will demonstrate a social conscience, possibly to gain support from consumers who buy their products, but will cut the profits of the shareholders in a company. Freidman also assumes that there is a link between the birth of ‘Ethical business’ and the growth of left-wing academia, particularly in the United States, although I am not convinced of the relation between the two and that one affects the other. However, Friedman believes that it is these academics that are making the businessmen act like â€Å"unwitting puppets† who are â€Å"preach ­ing pure and unadulterated socialism†. Still, I believe that Friedman is putting across his biased political views with this statement, where he thinks that anything relating to socialism is automatically bad so he does not really back up this quote. I also disagree with Friedman in tha t he believes that the â€Å"intellectual forces† really have that much influence on businessmen to make them â€Å"unwitting puppets†. The factor which would make businessmen turn to a more ethical approach could be down to a rapidly expanding interest in business ethics and the rise of the middle-class looking to ‘clear their conscience’ by buying ethically. 2. Friedman (1970) discusses whether corporations can have a â€Å"social responsibility† or whether having responsibilities is a uniquely human trait. Friedman argues, reasonably convincingly, that a company cannot have the responsibility since it is â€Å"artificial†. We can see this in his article when he says â€Å"Only people can have responsibilities. A corporation is an artificial person and in this sense may have artificial responsibilities†. This would lead him to the conclusion that corporations have no moral obligation to be ethical since they are not moral beings and that the only responsibilities of a company â€Å"is to increase its profits†.