Identity and identity politics Essay Example | Topics and Well Written Essays - 250 words

Identity and identity politics - Essay Example owever, they never lost their identity and their feeling is that the country retains it as a â€Å"residual sovereignty.† Scots’ have a party of their own that did so well last year and proved its worth and potentiality of their identity. Mr. Salmond, Scots’ first minister and leader of Scottish National party, wants a referendum by 2014 to fulfil the promise, (Ascherson web). According to Ford, social identities are a product of politics. He claims that â€Å"social identities are inherently and irreducibly political† (Ford web). It is true that some identities are a product of politics. Scots after winning elections last year, Mr. Salmond is leading them towards a referendum, which will see them as an independent country. Calhoun argues that identity is seen in the relationship between essence and appearance and that it had to be achieved for development, (Calhoun 37). I feel that this need to identify Scotland as a country is triggered by the political success. The idea of a possible referendum is quickly gaining acceptance among the Scots and therefore, it is just a matter of time before the overwhelming power of identity takes place. I think the main reason for Scots desire to move and be independent is to develop themselves as an independent nation. Identity is a great need of all human beings and Scots is no exception. Ford, Thompson, Richard. â€Å"Political Identity as Identity Politics.† Unbound Harvard Journal of the Legal Left. 2009. 10 March 2012. Macintyre, James. â€Å"From Devolution to Independence.† The New York Times, 2012. Web 9 March 2012.

Hydrocarbon Fuels Essay Example for Free

Hydrocarbon Fuels Essay Fuels are substances that burn in reactions with oxygen on a large scale, with transfer of energy to the surroundings. Fossil fuels are the most common and widely used fuels around today. The essential reaction for any chemical fuel includes: Fuel + Oxygen Oxidation + Energy transfer products Fossil fuels are a non renewable source of fuels and include coal, oil and gas. These are raw materials that supply feedback for most of our chemical industry. These have been produced over millions of years and are being consumed rapidly. If we run out of fossil fuels they cannot be reproduced which is why it is important to use them efficiently. Crude oil and natural gas provide fuel for heating, electricity generation and transport. Natural gas is a mixture of hydrocarbons with small molecules. These molecules are made of atoms of carbon and hydrogen. For example, natural gas used in the home is mainly methane, CH4. Crude oil is a complex mixture of hydrocarbons, with a varying composition depending on its source. The hydrocarbons in crude oil have different boiling points, according to the number of carbon atoms their molecules contain and how they are arranged. Fractional distillation uses the difference in boiling point to separate the hydrocarbons in crude oil. The fractionating column is cooler at the top than the bottom, so the vapours cool as they rise. Vapours condense onto a tray when they reach the part of the column which is cooler than their boiling point, they are therefore now separated. There is a greater demand for lighter short chain hydrocarbons such as petrol and naphtha and the demand for heavy long chain hydrocarbons is much less. E.g. bitumen Cracking is a form of thermal decomposition and is the process in which shorter more useful carbon chain hydrocarbons are produced from longer less useful chains by heating. This is done by breaking the carbon-carbon bonds which are very strongly attracted so the process of cracking has high activation energy. It is a free radical process and so it makes a mixture of products. Catalytic cracking is a Carbo Cation mechanism. It uses catalyst: zeolite at slight pressure- 4/5 atmospheres to make more fuels. It also makes aromatic hydrocarbons. Shape selectivity by a zeolite catalyst separation of isomers by a molecular sieve The advantages of using fossils is that very large amounts of electricity can be generated in one place using coal, fairly cheaply. Transporting oil and gas to the power stations is also very easy. Gas-fired power stations are very efficient and a fossil-fuelled power station can be built almost anywhere, so long as you can get large quantities of fuel to it. However there are many disadvantages the most common and serious being pollution. Spillage of fuels can cause great damage in streams and ponds resulting in immense loss of animal and plant life and an enormous cost of cleaning it up. Oxidation of carbon-based compounds produces vast amounts of carbon dioxide which contributes to the green house effect causing an increase in atmospheric temperatures which is then likely to cause changes in climate and weather patterns. A large variety of compounds, including carcinogens, appear in the smoke from burning coal and wood. Inefficient burning of carbon-based fuels in defective furnace and domestic gas fires produces poisonous gas carbon monoxide. This can cause problems in health as if it is breathed in it can take up the oxygen space in hemoglobin and react with the iron, this would mean that the body would not function properly and death will follow. Burning fuels also produces two other poisonous gases such as various nitrogen oxides and sulphur oxides. The sulphur oxide comes from the sulphur impurities in the fossil fuels however the nitrogen oxides are produced by the reaction of nitrogen and oxygen in the air caused by the heat of the burning. When these gases mix with clouds they form dilute sulphuric acid and dilute nitric acid. This then falls as acid rain which kills fish, trees and limestone buildings. Mining coal can be difficult and dangerous. Strip mining destroys large areas of the landscape. This image shows dead Effects of acid on stone Fish as a result of pollution sculpture There are some alternatives to fossil fuels that may provide a better environment these include the following: * BIOMASS: plants can be used directly as fuels e.g wood or they can be grown for conversion into fuels e.g sugar from sugar cane Advantage: renewable, helps to reduce waste and used with simple technology Disadvantage: not large enough to replace fossil fuels at present rates of use. * METHANOL: this alcohol can be used in racing cars and it is made quite cheaply from methane Advantage: methanol does not produce a lot of carbon monoxide when burnt Disadvantage: mixture of methanol and petrol absorb water and may cause corrosion of car engines * NUCLEAR FUELS: when the nuclei of atoms of isotopes of uranium undergo fission (splitting) in a chain reaction very large amounts of energy is released Advantage: there are no carbon, nitrogen and sulphur produced. Disadvantage: Radioactive waste products are difficult to store and treat. * MOVING AIR: WIND The energy of moving air is transferred into the motion of windmills and wind turbines Advantage: no pollution is produced and it is renewable Disadvantage: can be expensive to generate electricity for a large scale. Is not very reliable as it needs wind which is not always available. * MOVING: WATER Stored water behind dams or from waterfalls can be released through turbines and generate electricity Advantage: can be used on large scale and is quite predictable Disadvantage: quite costly * SUNLIGHT: Solar panels are used to heat water and photovoltaic cells are used to convert light into electricity Advantage: pollution free with no waste products Disadvantage: the sun is not always available in countries like the UK and also there is no sun at night time. * GEOTHERMAL: Water is pumped into wells in the hot rock zone is heated and used to heat buildings Advantage: available in large quantities and no pollution is produced Disadvantage: expensive and has some technological problems * HYDROGEN: Hydrogen is extracted from water by electrolysis and used on transport systems Advantage: available in large quantities and causes no air pollution Disadvantage: regarded as too dangerously explosive and it is too difficult to store Bibliography * OCR text book: Chemistry 1 * AS and A level chemistry revision guide * GCSE double science chemistry revision guide * Google research * http://www.darvill.clara.net/altenerg/fossil.htm

A Famous Metaphysical Poet Essay Example for Free

A Famous Metaphysical Poet Essay Andrew Marvell was a famous Metaphysical Poet. Marvell lived from 1621 to 1678 and made a few accomplishments, his poem has unique style and theme for his time, and his poem contains a deep analysis. He wrote several love poems; â€Å"To His Coy Mistress† was one of his most unusual poems for the time in history which he lived. Born on March 31, 1621, in Winestead-in-Holderness, Yorkshire, England Marvell was the son of an Anglican clergy man. He attended Hull Grammar school, and at the age of 12 began college at Cambridge University. He earned his bachelor’s degree in 1638, but it is believed that he stayed at Cambridge until 1641 for a master’s degree. Not much is known about Andrew Marvell’s life; though scholars do know in the 1650s he had a part in the English Government. In 1657 He was appointed Assistant Latin Secretary to the Council of the state; in 1659 he concentrated more on political satire and stopped writing poetry. During Marvell’s life time England’s government had some surprising changes. Monarchy and parliament worked together, but King James I did not have the skill to manage a country, but the government gained more issues when his son, Charles I succeeded him. King Charles I was overthrown and beheaded. England wanted to establish a new government, after doing so; Charles II was made King of England. Marvell died on August 16, 1678 due to a fever. â€Å"While he is not thought to be married, shortly after his death, a woman claiming to be his widow published a volume of his poetry† (Ruby 276). He was one of the chief wits and satirists, a Puritan, and a public defender of individual liberty during his time. Today he is just known for his poetry. (Margoliouth, Sackville-West, Hunt, Murray, Toliver, Legouis, Wallace, Friednreich, Donno. 1) In the 1600s Marvell’s poem â€Å"To His Coy Mistress† was seen as â€Å"obscene and obscure† because of his message in the poem, and the control the church had over the people. Marvell is considered to have been a carpe diem writer, and sometimes described as a metaphysical poet. Carpe diem means the writing style encourages a reader to â€Å"seize the day† because life is short; Metaphysical poets use many unique metaphors and were very appreciated for their originality. Jeffrey Karon states â€Å"To His Coy Mistress† may be one of Marvell’s most destructive poems. â€Å"Its strength is that having turned against itself in the expected manner of ironic poems, it then turns against its own internal objections† (Karon par. 39). In the poem, the speaker describes how he could worship his mistress forever; however part two the tone shifts to time rushing past and the mistress’s physical beauty being wasted away with it. The speaker wants to beat time and enjoy his mistress’s company. There are many different themes in â€Å"To His Coy Mistress† such as time, love, passion, seduction, beauty, and death. This poem is of forty-six lines, and three paragraphs dividing up the rhyming couplets. Marvell used personification, hyperboles, and very bizarre metaphors. The speaker is speaking to his mistress in a rhetorical situation. He passionately describes his love for her and there is not enough time to live to show her how beautiful she is, and how great his love is for her. He wants his love with his mistress to go further by getting intimate with each other, although she wants to save her virginity due to her religious views with the church. He informs her if their love is true and they are in love, they should further their relationship. The woman is said to be coy because she is taking too much time, and time doesn’t stop for anyone. â€Å"’To His Coy Mistress’ is a sublime example of a carpe diem poem, a Latin phrase meaning ‘seize the day’† (Adams par. 8). The first two lines of the poem the main theme, time, is introduced to the reader. It is basically saying life passes quickly and one should not waste their youth, that they should â€Å"seize the day. † The first paragraph of the poem the speaker describes how life is too short for them to waste time. He uses exotic metaphors such as, â€Å"vegetable love† to describe how long he could love his mistress. Beginning at line seven until line eighteen he uses hyperboles to describe the amount of years he could love her and devote to worship her. He describes her physical attractiveness and how long he could love every part of her body and of course her heart. In paragraph two the speaker goes from speaking of his love for his mistress to imagining her grave. He speaks of time as the driver in a chariot hurrying closer to them; he uses â€Å"hurrying† to the show the distress of the little time they have. A few lines down in this paragraph, he describes to his mistress her virginity will eventually over time mean nothing, and when she dies it will be an unusual and worthless treasure. In the first few lines of third and final paragraph the speaker describes his mistress as â€Å"morning dew† saying she is young and her skin a healthy glow just like the dew over the grass in the early morning. Another exotic metaphor he uses is â€Å"birds of prey. † He and his mistress are the birds, and they are preying on time. They want to eat and not be eaten. The speaker finally breaks through and wins his mistress over using the last few lines of the poem. He is saying to her they should take every part of themselves, the strong, the sweet, and the vulnerable, roll it up into a ball and come together as one to beat time. Since they cannot make the sun stay still they will race with him, the speaker using personification and making the sun seem like a person literally racing with him. Marvell was not acknowledged for his unique, but brilliant poems until after his death, he changed the meaning of Metaphysical Poet. Marvell made a few accomplishments, his poems usually had unique style and theme for his time, and his poem contains a deep analysis. This could be a perfect poem for someone interested in love poems with deep meaning.

Examining The Sound Navigation Technique Of Sonar Engineering Essay

Examining The Sound Navigation Technique Of Sonar Engineering Essay Sonar means sound navigation and ranging is a technique that uses sound propagation (usually underwater, as in Submarine navigation) to navigate, communicate with or detect other vessels. Two types of technology share the name sonar: passive sonar is essentially listening for the sound made by vessels; active sonar is emitting pulses of sounds and listening for echoes. Sonar may be used as a means of acoustic location and of measurement of the echo characteristics of targets in the water. Acoustic location in air was used before the introduction of radar. Sonar may also be used in air for robot navigation, and SODAR upward looking in-air sonar) is used for atmospheric investigations. The term sonar is also used for the equipment used to generate and receive the sound. The acoustic frequencies used in sonar systems vary from very low (infrasonic) to extremely high (ultrasonic). The study of underwater sound is known as underwater acoustics or hydro acoustics History Although some animals (dolphins and bats) have used sound for communication and object detection for millions of years, use by humans in the water is initially recorded by Leonardo Da Vinci in 1490: a tube inserted into the water was said to be used to detect vessels by placing an ear to the tube.[citation needed] In the 19th century an underwater bell was used as an ancillary to lighthouses to provide warning of hazards. The use of sound to echo locate underwater in the same way as bats use sound for aerial navigation seems to have been prompted by the Titanic disaster of 1912. The worlds first patent for an underwater echo ranging device was filed at the British Patent Office by English meteorologist Lewis Richardson a month after the sinking of the Titanic, and a German physicist Alexander Behm obtained a patent for an echo sounder in 1913. Canadian Reginald Fessenden, while working for the Submarine Signal Company in Boston, built an experimental system beginning in 1912, a system later tested in Boston Harbor, and finally in 1914 from the U.S. Revenue (now Coast Guard) Cutter Miami on the Grand Banks off Newfoundland Canada. In that test, Fessenden demonstrated depth sounding, underwater communications (Morse Code) and echo ranging (detecting an iceberg at two miles (3 km) range). The so-called Fessenden oscillator, at ca. 500 Hz frequency, was unable to determine the bearing of the berg due to t he 3 meter wavelength and the small dimension of the transducers radiating face (less than 1 meter in diameter). The ten Montreal-built British H class submarines launched in 1915 were equipped with a Fessenden oscillator. During World War I the need to detect submarines prompted more research into the use of sound. The British made early use of underwater hydrophones, while the French physicist Paul Langevin, working with a Russian immigrant electrical engineer, Constantin Chilowski, worked on the development of active sound devices for detecting submarines in 1915 using quartz. Although piezoelectric and magnetostrictive transducers later superseded the electrostatic transducers they used, this work influenced future designs. Performance factors The detection, classification and localization performance of a sonar depends on the environment and the receiving equipment, as well as the transmitting equipment in an active sonar or the target radiated noise in a passive sonar. Sound propagation Sonar operation is affected by variations in sound speed, particularly in the vertical plane. Sound travels more slowly in fresh water than in sea water, though the difference is small. The speed is determined by the waters bulk modulus and mass density. The bulk modulus is affected by temperature, dissolved impurities (usually salinity), and pressure. The density effect is small. The speed of sound (in feet per second) is approximately: 4388 + (11.25 ÃÆ'- temperature (in  °F)) + (0.0182 ÃÆ'- depth (in feet)) + salinity (in parts-per-thousand ). This empirically derived approximation equation is reasonably accurate for normal temperatures, concentrations of salinity and the range of most ocean depths. Ocean temperature varies with depth, but at between 30 and 100 meters there is often a marked change, called the thermo cline, dividing the warmer surface water from the cold, still waters that make up the rest of the ocean. This can frustrate sonar, because a sound originating on one side of the thermo cline tends to be bent, or refracted, through the thermo cline. The thermo cline may be present in shallower coastal waters. However, wave action will often mix the water column and eliminate the thermo cline. Water pressure also affects sound propagation: higher pressure increases the sound speed, which causes the sound waves to refract away from the area of higher sound speed. The mathematical model of refraction is called Snells law. If the sound source is deep and the conditions are right, propagation may occur in the deep sound channel. This provides extremely low propagation loss to a receiver in the channel. This is because of sound trapping in the channel with no losses at the boundaries. Similar propagation can occur in the surface duct under suitable conditions. However in this case there are reflection losses at the surface. In shallow water propagation is generally by repeated reflection at the surface and bottom, where considerable losses can occur. Sound propagation is affected by absorption in the water itself as well as at the surface and bottom. This absorption depends upon frequency, with several different mechanisms in sea water. Long-range sonar uses low frequencies to minimize absorption effects. The sea contains many sources of noise that interfere with the desired target echo or signature. The main noise sources are waves and shipping. The motion of the receiver through the water can also cause speed-dependent low frequency noise. Scattering When active sonar is used, scattering occurs from small objects in the sea as well as from the bottom and surface. This can be a major source of interference. This acoustic scattering is analogous to the scattering of the light from a cars headlights in fog: a high-intensity pencil beam will penetrate the fog to some extent, but broader-beam headlights emit much light in unwanted directions, much of which is scattered back to the observer, overwhelming that reflected from the target (white-out). For analogous reasons active sonar needs to transmit in a narrow beam to minimize scattering. Target characteristics The sound reflection characteristics of the target of an active sonar, such as a submarine, are known as its target strength. A complication is that echoes are also obtained from other objects in the sea such as whales, wakes, schools of fish and rocks. Passive sonar detects the targets radiated noise characteristics. The radiated spectrum comprises a continuous spectrum of noise with peaks at certain frequencies which can be used for classification. Countermeasures 1) Active countermeasures may be launched by a submarine under attack to raise the noise level, provide a large false target, and obscure the signature of the submarine itself. 2) Passive countermeasures include: There is a mounting noise-generating device on isolating devices. We use a sound-absorbent coating on the hulls of submarines, for example anechoic tiles. Active sonarà   Active sonar uses a sound transmitter and a receiver. When the two are in the same place it is monostatic operation. When the transmitter and receiver are separated it is bistatic operation. When more transmitters (or more receivers) are used, again spatially separated, it is multistate operation. Most sonars are used monostatically with the same array often being used for transmission and reception. Active son buoy fields may be operated multistatically. Active sonar creates a pulse of sound, often called a ping, and then listens for reflections (echo) of the pulse. This pulse of sound is generally created electronically using a sonar Projector consisting of a signal generator, power amplifier and electro-acoustic transducer/array. A beam former is usually employed to concentrate the acoustic power into a beam, which may be swept to cover the required search angles. Generally, the electro-acoustic transducers are of the Tonpilz type and their design may be optimized to achieve maximum efficiency over the widest bandwidth, in order to optimize performance of the overall system. Occasionally, the acoustic pulse may be created by other means, e.g. (1) Chemically using explosives (2) Air guns (3) Plasma sound sources. To measure the distance to an object, the time from transmission of a pulse to reception is measured and converted into a range by knowing the speed of sound. To measure the bearing, several hydrophones are used, and the set measures the relative arrival time to each, or with an array of hydrophones, by measuring the relative amplitude in beams formed through a process called beam forming. Use of an array reduces the spatial response so that to provide wide cover multibeam systems are used. The targets signal (if present) together with noise is then passed through various forms of signal processing, which for simple sonars may be just energy measurement. It is then presented to some form of decision device that calls the output either the required signal or noise. This decision device may be an operator with headphones or a display, or in more sophisticated sonar this function may be carried out by software. Further processes may be carried out to classify the target and localize it, as well as measuring its velocity. The pulse may be at constant frequency or a chirp of changing frequency (to allow pulse compression on reception). Simple sonars generally use the former with a filter wide enough to cover possible Doppler changes due to target movement, while more complex ones generally include the latter technique. Since digital processing became available pulse compression has usually been implemented using digital correlation techniques. Military sonars often have multiple beams to provide all-round cover while simple ones only cover a narrow arc, although the beam may be rotated, relatively slowly, by mechanical scanning. Particularly when single frequency transmissions are used, the Doppler effect can be used to measure the radial speed of a target. The difference in frequency between the transmitted and received signal is measured and converted into a velocity. Since Doppler shifts can be introduced by either receiver or target motion, allowance has to be made for the radial speed of the searching platform. One of the useful small sonar is similar in appearance to a waterproof flashlight. The head is pointed into the water, a button is pressed, and the device displays the distance to the target. Another variant is a fish finder that shows a small display with shoals of fish. Some civilian sonars approach active military sonars in capability, with quite exotic three-dimensional displays of the area near the boat. When active sonar is used to measure the distance from the transducer to the bottom, it is known as echo sounding. Similar methods may be used looking upward for wave measurement. Active sonar is also used to measure distance through water between two sonar transducers or a combination of a hydrophone (underwater acoustic microphone) and projector (underwater acoustic speaker). A transducer is a device that can transmit and receive acoustic signals (pings). When a hydrophone/transducer receives a specific interrogation signal it responds by transmitting a specific reply signal. To measure distance, one transducer/projector transmits an interrogation signal and measures the time between this transmission and the receipt of the other transducer/hydrophone reply. The time difference, scaled by the speed of sound through water and divided by two, is the distance between the two platforms. This technique, when used with multiple transducers/hydrophones/projectors, can calculate the relative positions of static and moving objects in water. In combat situations, an active pulse can be detected by an opponent and will reveal a submarines position. A very directional, but low-efficiency, type of sonar makes use of a complex nonlinear feature of water known as non-linear sonar, the virtual transducer being known as a parametric array. Project ARTEMIS Project ARTEMIS was one-of-a-kind low-frequency sonar for surveillance that was deployed off Bermuda for several years in the early 1960s. The active portion was deployed from a World War II tanker, and the receiving array was a built into a fixed position on an offshore bank. Transponder This is an active sonar device that receives a stimulus and immediately retransmits the received signal or a predetermined one. Passive sonar Passive sonar listens without transmitting. It is often employed in military settings, although it is also used in science applications, e.g., detecting fish for presence/absence studies in various aquatic environments see also passive acoustics and passive radar. In the very broadest usage, this term can encompass virtually any analytical technique involving remotely generated sound, though it is usually restricted to techniques applied in an aquatic environment. Identifying sound sources Passive sonar has a wide variety of techniques for identifying the source of a detected sound. For example, U.S. vessels usually operate 60 Hz alternating current power systems. If transformers or generators are mounted without proper vibration insulation from the hull or become flooded, the 60 Hz sound from the windings can be emitted from the submarine or ship. This can help to identify its nationality, as most European submarines have 50 Hz power systems. Intermittent sound sources (such as a wrench being dropped) may also be detectable to passive sonar. Until fairly recently, an experienced trained operator identified signals, but now computers may do this. Passive sonar systems may have large sonic databases, but the sonar operator usually finally classifies the signals manually. A computer system frequently uses these databases to identify classes of ships, actions (i.e. the speed of a ship, or the type of weapon released), and even particular ships. Publications for classification of sounds are provided by and continually updated by the US Office of Naval Intelligence. Noise limitations Passive sonar on vehicles is usually severely limited because of noise generated by the vehicle. For this reason, many submarines operate nuclear reactors that can be cooled without pumps, using silent convection, or fuel cells or batteries, which can also run silently. Vehicles propellers are also designed and precisely machined to emit minimal noise. High-speed propellers often create tiny bubbles in the water, and these cavitations have a distinct sound. The sonar hydrophones may be towed behind the ship or submarine in order to reduce the effect of noise generated by the watercraft itself. Towed units also combat the thermo cline, as the unit may be towed above or below the thermo cline. The display of most passive sonars used to be a two-dimensional waterfall display. The horizontal direction of the display is bearing. The vertical is frequency, or sometimes time. Another display technique is to color-code frequency-time information for bearing. More recent displays are generated by the computers, and mimic radar-type plan position indicator displays. Performance prediction Unlike active sonar, only one way propagation is involved. Because of the different signal processing used, the minimum detectable signal to noise ratio will be different. The equation for determining the performance of passive sonar is: SL à ¢Ã‹â€ Ã¢â‚¬â„¢ TL = NL à ¢Ã‹â€ Ã¢â‚¬â„¢ DI + DT where SL is the source level, TL is the transmission loss, NL is the noise level, DI is the directivity index of the array (an approximation to the array gain) and DT is the detection threshold. The figure of merit of passive sonar is: FOM = SL + DI à ¢Ã‹â€ Ã¢â‚¬â„¢ (NL + DT). Warfare Modern naval warfare makes extensive use of both passive and active sonar from water-borne vessels, aircraft and fixed installations. The relative usefulness of active versus passive sonar depends on the radiated noise characteristics of the target, generally a submarine. Although in WW II active sonar was used by surface craft-submarines avoided emitting pings which revealed their presence and position-with the advent of modern signal-processing passive sonar became preferred for initial detection. Submarines were then designed for quieter operation, and active sonar is now more used. In 1987 a division of Japanese company Toshiba reportedly sold machinery to the Soviet Union that allowed it to mill submarine propeller blades so that they became radically quieter, creating a huge security issue with their newer generation of submarines. Active sonar gives the exact bearing to a target, and sometimes the range. Active sonar works the same way as radar: a signal is emitted. The sound wave then travels in many directions from the emitting object. When it hits an object, the sound wave is then reflected in many other directions. Some of the energy will travel back to the emitting source. The echo will enable the sonar system or technician to calculate, with many factors such as the frequency, the energy of the received signal, the depth, the water temperature, the position of the reflecting object, etc. Active sonar is used when the platform commander determines that it is more important to determine the position of a possible threat submarine than it is to conceal his own position. With surface ships it might be assumed that the threat is already tracking the ship with satellite data. Any vessel around the emitting sonar will detect the emission. Having heard the signal, it is easy to identify the sonar equipment used and its position. Active sonar is similar to radar in that, while it allows detection of targets at a certain range, it also enables the emitter to be detected at a far greater range, which is undesirable. Since active sonar reveals the presence and position of the operator, and does not allow exact classification of targets, it is used by fast (planes, helicopters) and by noisy platforms but rarely by submarines. When active sonar is used by surface ships or submarines, it is typically activated very briefly at intermittent periods to minimize the risk of detection. Consequently active sonar is normally considered a backup to passive sonar. In aircraft, active sonar is used in the form of disposable son buoys that are dropped in the aircrafts patrol area or in the vicinity of possible enemy sonar contacts. Passive sonar has several advantages. Most importantly, it is silent. If the target radiated noise level is high enough, it can have a greater range than active sonar, and allows the target to be identified. Since any motorized object makes some noise, it may in principle be detected, depending on the level of noise emitted and the ambient noise level in the area, as well as the technology used. To simplify, passive sonar sees around the ship using it. On a submarine, nose-mounted passive sonar detects in directions of about 270 °, centered on the ships alignment, the hull-mounted array of about 160 ° on each side, and the towed array of a full 360 °. The invisible areas are due to the ships own interference. Once a signal is detected in a certain direction (which means that something makes sound in that direction, this is called broadband detection) it is possible to zoom in and analyze the signal received (narrowband analysis). This is generally done using a Fourier transform to show the different frequencies making up the sound. Since every engine makes a specific sound, it is straightforward to identify the object. Databases of unique engine sounds are part of what is known as acoustic intelligence or ACINT. Another use of passive sonar is to determine the targets trajectory. This process is called Target Motion Analysis (TMA), and the resultant solution is the targets range, course, and speed. TMA is done by marking from which direction the sound comes at different times, and comparing the motion with that of the operators own ship. Changes in relative motion are analyzed using standard geometrical techniques along with some assumptions about limiting cases. Passive sonar is stealthy and very useful. However, it requires high-tech electronic components and is costly. It is generally deployed on expensive ships in the form of arrays to enhance detection. Surface ships use it to good effect; it is even better used by submarines, and it is also used by airplanes and helicopters, mostly to a surprise effect, since submarines can hide under thermal layers. If a submarines commander believes he is alone, he may bring his boat closer to the surface and be easier to detect, or go deeper and faster, and thus make sounder. Examples of sonar applications in military use are given below. Many of the civil uses given in the following section may also be applicable to naval use. Anti-submarine warfare Variable Depth Sonar and its winch until recently, ship sonars were usually with hull mounted arrays, either amidships or at the bow. It was soon found after their initial use that a means of reducing flow noise was required. The first were made of canvas on a framework, and then steel ones were used. Now domes are usually made of reinforced plastic or pressurized rubber. Such sonars are primarily active in operation. An example of conventional hull mounted sonar is the SQS-56. Because of the problems of ship noise, towed sonars are also used. These also have the advantage of being able to be placed deeper in the water. However, there are limitations on their use in shallow water. These are called towed arrays (linear) or variable depth sonars (VDS) with 2/3D arrays. A problem is that the winches required to deploy/recover these are large and expensive. VDS sets are primarily active in operation while towed arrays are passive. An example of a modern active/passive ship towed sonar is Sonar 2087 made by Thales Underwater Systems. Torpedoes Modern torpedoes are generally fitted with active/passive sonar. This may be used to home directly on the target, but wake following torpedoes are also used. An early example of an acoustic homer was the Mark 37 torpedo. Torpedo countermeasures can be towed or free. An early example was the German Sieglinde device while the Pillenwerfer was a chemical device. A widely used US device was the towed Nixie while MOSS submarine simulator was a free device. A modern alternative to the Nixie system is the UK Royal Navy S2170 Surface Ship Torpedo Defense system. Mines Mines may be fitted with a sonar to detect, localize and recognize the required target. Further information is given in acoustic mine and an example is the CAPTOR mine. Mine countermeasures Mine Countermeasure (MCM) Sonar, sometimes called Mine and Obstacle Avoidance Sonar (MOAS), is a specialized type of sonar used for detecting small objects. Most MCM sonars are hull mounted but a few types are VDS design. An example of a hull mounted MCM sonar is the Type 2193 while the SQQ-32 Mine-hunting sonar and Type 2093 systems are VDS designs. See also Minesweeper (ship) Submarine navigation Submarines rely on sonar to a greater extent than surface ships as they cannot use radar at depth. The sonar arrays may be hull mounted or towed. Information fitted on typical fits is given in Yoshiro class submarine and Swift sure class submarine. Aircraft Helicopters can be used for antisubmarine warfare by deploying fields of active/passive son buoys or can operate dipping sonar, such as the AQS-13. Fixed wing aircraft can also deploy son buoys and have greater endurance and capacity to deploy them. Processing from the son buoys or dipping sonar can be on the aircraft or on ship. Helicopters have also been used for mine countermeasure missions using towed sonars such as the AQS-20A Ocean surveillance For many years, the United States operated a large set of passive sonar arrays at various points in the worlds oceans, collectively called Sound Surveillance System (SOSUS) and later Integrated Undersea Surveillance System (IUSS). A similar system is believed to have been operated by the Soviet Union. As permanently mounted arrays in the deep ocean were utilized, they were in very quiet conditions so long ranges could be achieved. Signal processing was carried out using powerful computers ashore. With the ending of the Cold War a SOSUS array has been turned over to scientific use. Underwater security Sonar can be used to detect frogmen and other scuba divers. This can be applicable around ships or at entrances to ports. Active sonar can also be used as a deterrent and/or disablement mechanism. One such device is the Cerberus system. Hand-held sonar Limpet Mine Imaging Sonar (LIMIS) is hand-held or ROV-mounted imaging sonar designed for patrol divers (combat frogmen or clearance divers) to look for limpet mines in low visibility water. The LUIS is imaging sonar for use by a diver. Integrated Navigation Sonar System (INSS) is small flashlight-shaped handheld sonar for divers that display range. Intercept sonar This is sonar designed to detect and locate the transmissions from hostile active sonars. An example of this is the Type 2082 fitted on the British Vanguard class submarines. Uses in daily life Fisheries Fishing is an important industry that is seeing growing demand, but world catch tonnage is falling as a result of serious resource problems. The industry faces a future of continuing worldwide consolidation until a point of sustainability can be reached. However, the consolidation of the fishing fleets are driving increased demands for sophisticated fish finding electronics such as sensors, sounders and sonars. Historically, fishermen have used many different techniques to find and harvest fish. However, acoustic technology has been one of the most important driving forces behind the development of the modern commercial fisheries. Sound waves travel differently through fish than through water because a fishs air-filled swim bladder has a different density than seawater. This density difference allows the detection of schools of fish by using reflected sound. Acoustic technology is especially well suited for underwater applications since sound travels farther and faster underwater than in air. Today, commercial fishing vessels rely almost completely on acoustic sonar and sounders to detect fish. Fishermen also use active sonar and echo sounder technology to determine water depth, bottom contour, and bottom composition. Cabin display of fish finder sonar Companies such as Ray marine UK makes a variety of sonar and acoustic instruments for the deep sea commercial fishing industry. For example, net sensors take various underwater measurements and transmit the information back to a receiver onboard a vessel. Each sensor is equipped with one or more acoustic transducers depending on its specific function. Data is transmitted from the sensors using wireless acoustic telemetry and is received by a hull mounted hydrophone. The analog signals are decoded and converted by a digital acoustic receiver into data which is transmitted to a bridge computer for graphical display on a high resolution monitor. Echo sounding An echo-sounder sends an acoustic pulse directly downwards to the seabed and records the returned echo. The sound pulse is generated by a transducer that emits an acoustic pulse and then listens for the return signal. The time for the signal to return is recorded and converted to a depth measurement by calculating the speed of sound in water. As the speed of sound in water is around 1,500 meters per second, the time interval, measured in milliseconds, between the pulse being transmitted and the echo being received, allows bottom depth and targets to be measured. The value of underwater acoustics to the fishing industry has led to the development of other acoustic instruments that operate in a similar fashion to echo-sounders but, because their function is slightly different from the initial model of the echo-sounder, have been given different terms. Net location The net sounder is an echo sounder with a transducer mounted on the headline of the net rather than on the bottom of the vessel. Nevertheless, to accommodate the distance from the transducer to the display unit, which is much greater than in a normal echo-sounder, several refinements have to be made. Two main types are available. The first is the cable type in which the signals are sent along a cable. In this case there has to be the provision of a cable drum on which to haul, shoot and stow the cable during the different phases of the operation. The second type is the cable less net-sounder such as Marports Trawl Explorer in which the signals are sent acoustically between the net and hull mounted receiver/hydrophone on the vessel. In this case no cable drum is required but sophisticated electronics are needed at the transducer and receiver. The display on a net sounder shows the distance of the net from the bottom (or the surface), rather than the depth of water as with the echo-sounders hull-mounted transducer. Fixed to the headline of the net, the footrope can usually be seen which gives an indication of the net performance. Any fish passing into the net can also be seen, allowing fine adjustments to be made to catch the most fish possible. In other fisheries, where the amount of fish in the net is important, catch sensor transducers are mounted at various positions on the cod-end of the net. As the cod-end fills up these catch sensor transducers are triggered one by one and this information is transmitted acoustically to display monitors on the bridge of the vessel. The skipper can then decide when to haul the net. Modern versions of the net sounder, using multiple element transducers, function more like sonar than an echo sounder and show slices of the area in front of the net and not merely the vertical view that the initial net sounders used. The sonar is an echo-sounder with a directional capability that can show fish or other objects around the vessel good Ship velocity measurement Sonars have been developed for measuring a ships velocity either relative to the water or to the bottom. Scientific applicationsà   Biomass estimation Detection of fish, and other marine and aquatic life, and estimation their individual sizes or total biomass using active sonar techniques. As the sound pulse travels through water it encounters objects that are of different density or acoustic characteristics than the surrounding medium, such as fish, that reflect sound back toward the sound source. These echoes provide information on fish size, location, abundance and behavior. Data is usually processed and analyzed using a variety of software such as Echo view. Wave measurement An upward looking echo sounder mounted on the bottom or on a platform may be used to make measurements of wave height and period. From this statistics of the surface conditions at a location can be derived. Water velocity measurem

Jess Martin The Theme Of The Outsiders :: essays research papers

  Ã‚  Ã‚  Ã‚  Ã‚  The Outsiders, an enthralling tale by S.E. Hinton, is an excellent story about the hardships and triumphs experienced by the Greasers and the Socs, two rival gangs. This novel suggests the stories ¹ content because the Greasers are a gang of social outcasts and misfits. This novel ¹s theme is very specific; people, no matter what their social background, strive for the same goals and experience the same disappointments. This novel shows this theme throughout a detailed story line.   Ã‚  Ã‚  Ã‚  Ã‚  The fictional novel is set in a moderate-size city, possibly near Texas, in the late 1960 ¹s. Ponyboy, the main character, lives with his brothers as a greaser. One day Ponyboy and Johnny, Ponyboy ¹s best friend, get jumped by a group of Socs. The Socs start to drown Ponyboy in a fountain. Johnny, realizing they might kill Ponyboy, kills Bob, one of the Socs with his switchblade. Johnny and Ponyboy run to a fellow Greaser, Dally, who is always in trouble with the law. Dally helps them by giving them some money, a gun, and a place to hide. They hide in a church outside of town for a week until Dally says it ¹s okay to come out. They go out to eat and when they get back to the church they find it burning. When they see that there are kids inside and the fire could have been started by their cigarettes, they run inside to save the kids. Johnny and Dally are hurt in the fire and taken to the hospital. They are hailed as heroes in the local paper. Dally breaks out of the hospital to fight in a rumble against the Socs. While the Greasers beat the Socs, Johnny dies in the hospital. When Dally finds out he goes out and robs a grocery store. When the cops pull up he pulls out an empty gun so the cops shoot him.   Ã‚  Ã‚  Ã‚  Ã‚  The theme of this novel is that all people are set back at times and they all want the same basic things. This theme is expressed in the novel several times. Disappointments are shown when Bob dies and the Socs grieve for him, when Ponyboy ¹s parents die and they are upset, and when Johnny dies and it disturbs the Greasers. It is shown that the Greasers and Socs strive for the same goals when Darry, Ponyboy ¹s older brother, tells him that he should succeed in school and make something of himself, and

Essay --

Legalizing Organ Sales When an individual thinks of the United States of America, the thought of hope and freedom comes to mind, but behind closed doors there is something opposite of that. There is a world where human organs give hope and freedom to people, not the promises of America. There is a world where one organ can be the difference between life or death for patients. This organ world can be fixed by allowing the sales of organs in America, allowing more organs for more patients. The sale of human organs should be legalized because it would stop the black market and people are in need of organs. The black market is an illegal underground economy, where people can sell anything they want, including organs. This is a very dangerous market, because people will do virtually anything to make money off of organs, including harming other people. â€Å"Reports on black market surgeries detail operations taking place in outdated, dangerous facilities† ( The Sale of Human Organs Should be Allowed 2). Having these operations being done for the black market is very hazardous and unsafe, pe...

Performance Management System Essay -- Managing business Essays

Performance Management System Introduction This report is an attempt to analyse the existing Performance Management System for Large Financial Service Organisation (LFSO) and from this information, recommend, and implement an appropriate new performance management system. LFSO is an organisation, which traditionally has a paternalistic culture with low levels of unionisation. LFSO current Performance Management system was implemented two years ago changing the nature of the previous incremental salary scales described as Prerogatives by Lupton and Bowey and led to the abolition of the annual cost of living increment. This change by LFSO was an attempt to achieve a strategic, integrative and flexible approach to pay, in order to address its organisational objectives. Therefore it  ¡Ã‚ ¥reflected on a pluralist approach with the use of job evaluated grade structures regarding financial rewards and benefits ¡Ã‚ ¦. (Heery, 1996) despite the fact that with most paternalistic culture have a Unitarist approach to Performance Management systems. Initial research conducted by the organisation indicated that objectives are not always established and reviews were spasmodic. There was a high degree of resentment between the different members of staff leading to unhealthy competitiveness and unwillingness to support others. (Kerr, 1995) describe this behaviour as  ¡Ã‚ ¥esprit de corps ¡Ã‚ ¦. This resulted in an increase in general grievances. The BFU have been aware of this anxiety and have started a strong recruitment drive amongst employees but no figures on existing membership were available. ¡Ã‚ ¦ In general, both employees and management did not fully understand the scheme at its inception and saw it simply as a cost cutting exercise. The reward levels introduced were seen to be too small to act as a  ¡Ã‚ ¥motivator ¡Ã‚ ¦. There was also debate about the role of the annual appraisal interview as there was no consensus view on the purpose of these, which were regarded as an  ¡Ã‚ ¥inconvenience ¡Ã‚ ¦. Now two years into the scheme, LSFO is facing the threat of a  ¡Ã‚ ¥Bargaining Unit ¡Ã‚ ¦ or possible Unionisation. Alongside high levels of dissatisfaction from employees and some line managers who have also expressed serious concerns about their role in the process. The system itself is under severe criticism with large numbers of appeals although only a very few of these have been upheld. ... ...ments around these decisions. The manager will have in place a formal quality monitoring procedure and adherence to this will form part of the team and individual reward and appraisal procedure. As the BFU has started to implement a strong recruitment drive amongst LFSO employees, the management/ and HR Manager should consider meeting with the union to obtain its views on a partnership agreement with the organisation. This approach would recognise the possible impact BFU may have on the new system and would demonstrate a gesture of  ¡Ã‚ ¥goodwill ¡Ã‚ ¦ by the management team. It would also address the collective representation can help achieve important business objectives, including good communication. In conclusion it must be emphasised that an effective Performance Management system ensures that both Managers and employees understand each other ¡Ã‚ ¦s expectations, and how these are incorporated into the Corporate Strategy and how these impact upon their own context  ¡V their roles, behaviours, relationships and interactions, rewards and futures. Bibliography Books Beardwell, I. And Holden, L. (2001) Human Resource Management: A Contemporary Approach 3rd Ed. Prentice Hall Performance Management System Essay -- Managing business Essays Performance Management System Introduction This report is an attempt to analyse the existing Performance Management System for Large Financial Service Organisation (LFSO) and from this information, recommend, and implement an appropriate new performance management system. LFSO is an organisation, which traditionally has a paternalistic culture with low levels of unionisation. LFSO current Performance Management system was implemented two years ago changing the nature of the previous incremental salary scales described as Prerogatives by Lupton and Bowey and led to the abolition of the annual cost of living increment. This change by LFSO was an attempt to achieve a strategic, integrative and flexible approach to pay, in order to address its organisational objectives. Therefore it  ¡Ã‚ ¥reflected on a pluralist approach with the use of job evaluated grade structures regarding financial rewards and benefits ¡Ã‚ ¦. (Heery, 1996) despite the fact that with most paternalistic culture have a Unitarist approach to Performance Management systems. Initial research conducted by the organisation indicated that objectives are not always established and reviews were spasmodic. There was a high degree of resentment between the different members of staff leading to unhealthy competitiveness and unwillingness to support others. (Kerr, 1995) describe this behaviour as  ¡Ã‚ ¥esprit de corps ¡Ã‚ ¦. This resulted in an increase in general grievances. The BFU have been aware of this anxiety and have started a strong recruitment drive amongst employees but no figures on existing membership were available. ¡Ã‚ ¦ In general, both employees and management did not fully understand the scheme at its inception and saw it simply as a cost cutting exercise. The reward levels introduced were seen to be too small to act as a  ¡Ã‚ ¥motivator ¡Ã‚ ¦. There was also debate about the role of the annual appraisal interview as there was no consensus view on the purpose of these, which were regarded as an  ¡Ã‚ ¥inconvenience ¡Ã‚ ¦. Now two years into the scheme, LSFO is facing the threat of a  ¡Ã‚ ¥Bargaining Unit ¡Ã‚ ¦ or possible Unionisation. Alongside high levels of dissatisfaction from employees and some line managers who have also expressed serious concerns about their role in the process. The system itself is under severe criticism with large numbers of appeals although only a very few of these have been upheld. ... ...ments around these decisions. The manager will have in place a formal quality monitoring procedure and adherence to this will form part of the team and individual reward and appraisal procedure. As the BFU has started to implement a strong recruitment drive amongst LFSO employees, the management/ and HR Manager should consider meeting with the union to obtain its views on a partnership agreement with the organisation. This approach would recognise the possible impact BFU may have on the new system and would demonstrate a gesture of  ¡Ã‚ ¥goodwill ¡Ã‚ ¦ by the management team. It would also address the collective representation can help achieve important business objectives, including good communication. In conclusion it must be emphasised that an effective Performance Management system ensures that both Managers and employees understand each other ¡Ã‚ ¦s expectations, and how these are incorporated into the Corporate Strategy and how these impact upon their own context  ¡V their roles, behaviours, relationships and interactions, rewards and futures. Bibliography Books Beardwell, I. And Holden, L. (2001) Human Resource Management: A Contemporary Approach 3rd Ed. Prentice Hall