Science and Technology Custom Essay samples, Free samples: college essays, admission, argumentive essays


	▪ American History ▪ Art ▪ Biographies ▪ Business ▪ Case Studies ▪ Communication & Media ▪ Computer Technologies ▪ Controversial Topics ▪ Culture ▪ Economics ▪ Education ▪ Environmental Issues ▪ Finance		▪ Geography ▪ Health ▪ History ▪ Internet ▪ Management ▪ Media ▪ Philosophy ▪ Politics ▪ Religion ▪ Roman History ▪ Science and Technology Ancient Technologies Automobile Chemical Industry Combustion Engine Electrical Industry Electricity Applications Electricity Generation Energy Sources Extraction of Metals Food Preservation Food Technology Fossil Fuels Industrial Revolution Technologies Iron Metallurgy Natural Gas Natural Power Nuclear Power Radio and Television Road Building Rubber and Oil Steam Power Steamships Steel Industry Synthetic Materials Technical Innovations Turbine and Power Stations ▪ Sociology ▪ World Literature


	The History of HIV/AIDS

	Imagine a disease that was usually fatal and could spread each and every time two people have sex. Now imagine that that disease progressed so slowly that it took an average of ten years from the time of infection until the infected person's death, sometimes as much as twenty years. Let's also imagine that the disease was caused by a virus so small, a mere 130 millionth of a millimeter in diameter, that if it was magnified several times, it still could not be seen with the naked eye. And what if the disease affected mostly people in the prime of their lives, rather than at the end of their years? And what if the disease produced hideous symptoms like purplish blotches on the skin, extreme fatigue, and severe weight loss? And imagine that disease was new and spreading around the world at an alarming rate, infecting tens of millions of people.


	▪	Alternative Schooling
	▪	Freedom of Speech: Hustler Magazine v. Falwell
	▪	Homosexuality: Biology and/or Culture?
	▪	Fossil Fuels: Coal, Gas, and Petroleum
	▪	Generating and Transmitting Electricity
	▪	Rise of the Steel Industry
	▪	The Development of the Automobile
	▪	Extinction of Species
	▪	Legalization of Drugs
	▪	Corporate Social Responsibility
	▪	The U.S.A. Patriot Act
	▪	Death Penalty Contradictions
	▪	The Right to Die
	▪	Affirmative Action: Pursuing Fairness
	▪	The Abortion Reform Movement
	▪	Puritanism in America
	▪	Early Christian Art
	▪	Theodore Roosevelt
	▪	Labor Rights
	▪	Medieval Chivalry
	▪	Understanding Marijuana
	▪	Medicine in the Classical World
	▪	Health Care Policy in the US
	▪	Psychedelic Drugs Abuse
	▪	Ethics of Doctor-Patient Relationships
	▪	Religion of Rome and Early Italy
	▪	Standardized Testing
	▪	Economics of Alfred Marshall
	▪	Confucian Moral Self Cultivation
	▪	Genocide in Rwanda
	▪	Andy Warhol
	▪	Accounting Ethics
	▪	Benito Mussolini
	▪	Anthony Comstock
	▪	Henry Ford
	▪	Bram Stoker
	▪	The Television Industries: Broadcast, Cable, and Satellite
	▪	Online Gambling
	▪	New Spain
	▪	Homeopathy
	▪	International Financial Flows
	▪	Experiencing Culture Shock
	▪	Computer-Mediated Communication
	▪	Political Advertising
	▪	International Human Rights
	▪	The Iran-Contra Affairs

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Science and Technology Custom Essays samples

▪	Ancient Technologies


	Technologies in Classical Society

	The period lasting from about 600 B.C. to A.D. 400 is dominated by classical civilization--the culture of the Greeks and Romans. The Greek scientists contributed an invaluable new approach to science: they were the first to study natural objects and phenomena for the sake of these things themselves rather than as problems primarily connected with philosophy and religion. The earliest group of Greek natural philosophers was known as the Ionian school, for its members lived in the cities on the west coast of Asia Minor, which according to tradition had been colonized by the Ionian tribes. These cities were important centers of trade where the worlds of the East and West came in close contact. The older science and technology of the East had more influence on Greek science than was admitted a generation ago. At any rate the Greeks transformed these foreign elements into something peculiarly their own. The lack of adequate instruments, the tendency to build theories on only a handful of facts, and the severance of the bonds with technology and engineering blocked the path of classical science. The Greeks and Romans were fully convinced that science had arisen from practical needs. Eudemus the mathematician (fourth century B.C.) was the first to tell us that the Egyptians had developed their mathematics because the floods destroyed the boundaries of their farmlands. The great Roman architect Vitruvius (first century B.C.) was convinced that "only those who have mastered theory and practice are fully equipped to achieve their task with honor."

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▪	Automobile


	The Development of the Automobile

	The steam engine was too bulky to be used as a source of power for mechanically propelled road vehicles; what was needed was an engine that would combine the fire box, boiler, and cylinder of a steam plant in a small lightweight unit. The internal combustion engine, in which injected fuel mixed with air is exploded to drive the piston in a cylinder, proved to be the answer. It could supply more power per weight than a steam engine, and its moderate fuel consumption made long-distance travel not only possible but economical. The evolution of the internal-combustion engine was conditioned by the increasing supply of cheap fuel and cheap steel. The supplies of gas or alcohol were too limited for a rapid development of the use of automobiles. It was then that petroleum entered the picture.

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▪	Chemical Industry


	The Rise of Chemical Industry

	During the Industrial Revolution the rapidly growing textile and other industries demanded larger supplies of chemicals. Their manufacture had mostly been in the hands of distillers, druggists, and apothecaries. They had produced on a laboratory scale, which had been quite sufficient for the limited demand. Now the growing needs called for large-scale production. Unfortunately, chemistry was still in a qualitative stage and was engaged in violent discussions on the phlogiston theory. Not until the end of the eighteenth century did chemistry, through the efforts of Lavoisier and his school, become a quantitative science to guide the chemical industry. The manufacture of chemicals was therefore dependent solely on practical experience, and the early chemical factories were typically "enlarged laboratory processes." They had to struggle through the difficult stage of adapting their "pilot" processes to large-scale production.

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▪	Combustion Engine


	The Internal Combustion Engine

	The history of the internal combustion engine in the twentieth century follows three different paths, of which only one led to a complete innovation. These paths were represented by the Otto engine, the Diesel engine, and the gas turbine; it was the last of these that was wholly new. All paths led eventually to a heavy dependence on oil products as a source of motive power, particularly for transport, the consequences of which became painfully apparent in the 1970s.

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▪	Electrical Industry


	Electrical Supply Industry

	The foundation of the electrical supply industry -- an important addition to existing public utilities -- had been firmly laid by 1900. S. Z. Ferranti in Britain and George Westinghouse in the USA had recognized that the future of the industry, like that of the gas industry some eighty years earlier, lay not with local generation but with generation at big central stations serving large areas. Implicit in this was transmission of high voltages, to avoid excessive power loss; this in turn implied the use of alternating rather than direct current because high-voltage direct-current generators are relatively difficult to construct; but, as we shall see, in certain circumstances direct current had important applications. Moreover, alternating current can easily be reduced from high voltage to low by means of the transformer, a simple device involving no moving parts. Alternating supply did present a difficulty, however, if demand was such that generators had to be run in parallel: it was then difficult to keep the supply in phase. C. A. Parsons's steam turbine provided the high-speed engine desirable for driving the new generators: his first turbo-alternator -- operating at 4800 revolutions a minute -- was installed in the Forth Banks power-station in Britain as early as 1888. Water turbines, too, could be worked at high speeds, and hydroelectric schemes were developed where circumstances were favorable. Construction of the first major installation of this kind was begun at Niagara in 1886; it was designed to have an ultimate capacity of 200 000 h.p.

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▪	Electricity Applications


	The Applications of Electricity

	The development of batteries and generators created, as we have seen, the possibility of supplying electricity on a large scale. The first important application was the transformation of electricity into mechanical energy by means of the electric motor. It is strange, indeed, to find that, though generator and electric motor clearly work on the same principle, their development for a long time followed different lines. The earlier models by Faraday and Barlow, demonstrating the principle of the electric motor, were mere toys. Thomas Davenport, buying one of Henry's electromagnets, succeeded in developing a practical electric motor in 1835. Improving his first patent application of 1836, he later built a motor that drove a printing press in New York in the year 1839. At the same time, von Jacobi, inspired by Faraday, reported his experiments to the French Academy and drove a small boat along the River Neva in St. Petersburg by means of an electric motor in 1838. However, the spread of the motor had to wait for a source of cheap current, for batteries were too expensive for this purpose.

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▪	Electricity Generation


	Generating and Transmitting Electricity

	Though in the nineteenth century the old sources of power continued in use, their relative importance changed greatly. The windmill remained in use for drainage purposes. Because of their limited power, windmills were soon displaced in industry by steam engines, which came to the fore very rapidly, but were not unchallenged. The eighteenth-century experiments with electricity in laboratories and salons had soon led to research into the possibilities of storing electricity. The famous Leyden jar, invented simultaneously in 1745 by a German Lutheran pastor and a Dutch scientist, van Musschenbroek, gave little more than a flash of "static" electricity when discharged.

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▪	Energy Sources


	The Changing Patterns of Energy Sources

	Changes in the source and utilization of energy again reveal the first half of the twentieth century as a period of transition. In 1900 industrial and domestic demands for energy were growing rapidly, but lack of energy was not seen as any bar to technological advance. There were vast reserves of coal cheaply available, and the petroleum industry, though still in its infancy, clearly represented a major new source of fossil fuel. Coal had long been the basis of a flourishing and expanding gas industry. Electricity represented a new and flexible kind of energy whose potential value was already becoming clear. Although its production depended largely on generating steam in coal-fired boilers -- so that it was an indirect way of using fossil fuel rather than a new source of energy --, by the 1890s the Niagara project had demonstrated the possibilities of hydroelectric power in favorable situations. While there would inevitably be problems of continuously balancing supply and demand, there seemed no reason to doubt that, overall, ample energy would be available for all industrial developments.

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▪	Extraction of Metals


	Metals and Their Extraction

	Twentieth-century technology created an almost insatiable demand for metals-familiar metals serving familiar needs, but on a far larger scale; familiar metals serving quite new needs; and new metals being introduced. To meet the huge demand in a competitive world, the efficiency of traditional processes was improved and, as technological development in other fields permitted, new processes were devised. The development of the electrical industry, for example, made possible the wide use of the electric furnace in steel making and the introduction of electrochemical methods on a large scale for metals such as aluminum. As in virtually all other industries, operations demanding heavy manual labor were increasingly mechanized. The working of metals will be dealt with in a later chapter, and at this point we will concern ourselves only with their extraction.

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▪	Food Preservation


	The Canning and Shipping of Food

	As mankind spread over the entire face of the globe and transportation facilities increased, food from different climates became more easily available. The problem of food supply had grown very serious in the nineteenth century, when large towns and cities sprang up and dense populations were concentrated in industrial areas where food could not be produced locally in sufficient quantities but had to be imported mainly from agricultural districts and countries. Hence the transport, and above all the preservation, of food became a major problem. It has been speculated that Napoleon would have conquered Russia had he adopted canned food for his army, but of course such speculations are useless. The oldest ways of preserving food were salting, smoking, and drying. Drying alone is hardly ever sufficient, for three quarters of the food eaten by man has too high a fat content and unless preserved becomes spoiled in a very short time. Hence sterilization by heat alone will not suffice unless air is kept away from the heated food, as in canning. As long as the biological reasons underlying the decomposition of food were not completely understood, the various means that were devised for preserving food could not be completely successful.

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▪	Food Technology


	The Development of the Food Industry

	The development of the food industry followed a trend towards centralized production. In 1900 most food was still processed locally, either in the home or in small establishments, like bakeries, supplying a limited market. Food-processing factories were already well established for certain products, but their contribution was, in relative terms, much smaller than it was to be by mid-20th century. To some extent this can be associated with social factors: the middle-class housewife, at least in Europe, prided herself on her household management and disdained ready-prepared food. With domestic help still easily available she could afford this prejudice; moreover, while the prejudice existed, the food manufacturers had no great incentive to improve quality. With the poorer working-class housewife the situation was different: quantity was at least as important as quality, and she was quite happy to see some of her domestic chores translated to the factory.

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▪	Fossil Fuels


	Fossil Fuels: Coal, Gas, and Petroleum

	Of the fossil fuels coal, as we have seen, retained a commanding position throughout the first half of 20th century, though world output after the First World War remained fairly static. If we look at individual countries, however, the situation is rather different: there were considerable differences in the uses to which coal was put and in the economics of its production. In some countries, such as Germany and Austria, the variety known as lignite was extensively mined. This is a brown coal, with a low calorific value, that is intermediate between peat and the hard black bituminous coals familiar in Britain. Again, not all coals are suitable for the manufacture of metallurgical coke, essential for steel-making. Thus a particular region may be rich in coal, but nevertheless have to import varieties to satisfy local requirements. As we shall see, a similar position pertains in the case of petroleum. Although the North Sea was to make Britain self-sufficient in oil, it did not make her independent of imports. For certain purposes Middle East crudes were necessary, though the cost of these could be offset by export-of North Sea oil to countries, such as the USA, where it was in demand.

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▪	Industrial Revolution Technologies


	Technologies of Industrial Revolution

	The great events characterizing the period of Industrial Revolution are the development of iron metallurgy, the evolution of the steam engine, the general use of coal instead of wood, the rise of industrial chemistry, and the establishment of machine industry. These events served to raise the barriers imposed by limited supplies of food, fuel, iron, yarn, and transport. They could not have occurred without the background of scientific thought provided by the scientists forming part of the generation between Francis Bacon and Isaac Newton. This background underlay all of the useful inventions of the Industrial Revolution. Since the appropriate symbol of this period is the steam engine, it will be well to review the power resources of this period.

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▪	Iron Metallurgy


	The Development of Metallurgy

	Generations of pioneers had experimented with coal as a substitute for charcoal in metallurgy. Dun Dudley in his Metallum Martis claims to have run a blast furnace with coal in 1621, but the evidence for it is doubtful. Coal as such continued to spoil the good iron by giving off sulfurous fumes. Though many inventors brought forward various processes for using coal in place of charcoal, the ironmasters regarded each new attempt with some degree of suspicion. Moreover, the blast in the furnaces then used was still insufficient to permit the use of coke. Some of the primitive coke produced failed because it was too soft for stacking ore in the blast furnace. This was due to the fact that indiscriminate experimenters were using all kinds of coal. The production of good hard coke was the key to the problem.

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▪	Natural Gas


	Natural Gas Usage

	In America the gas industry developed very differently from that in Europe. Initially, it was quick to adopt the coal carbonization process: the streets of Baltimore were lit by coal gas as early as 1816. But in areas where natural gas was available -- it was often encountered at quite shallow levels in the search for petroleum -- it was piped away for domestic and industrial use. Although attempts to utilize natural gas in America can be traced back at least to 1821, the first commercial success seems to have been at Titusville in 1873. Thereafter, the natural-gas industry expanded enormously and transmission over long distances became commonplace. Between 1935 and 1950 sales of natural gas nearly quadrupled and represented more than go per cent of total gas sales. In 1955 one new gas well was said to be being brought into production every 23 minutes. At the same time there were 115 000 miles of transmission mains to convey natural gas to gas companies which, of course, had their own distribution system for their consumers. An outstanding technological achievement was that of the Trans-Continental Gas Pipeline Corporation, which in 1951 completed a 30-inch pipeline 1840 miles long to transport gas from the coast of the Texas-Louisiana Gulf to the fuel-hungry areas around New York, New Jersey, and Philadelphia.

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▪	Natural Power