Compare & Contrast Han and Rome Essay Example for Free

Compare Contrast Han and Rome Essay When Han China and Imperial Rome are compared, one can find both similarities and differences in terms of techniques of imperial administration. A similarity would be that both are bureaucracies. However, both are also different. One major difference is that Han China had the civil service exams. They also differed because Han China had a much greater emphasis on religion than the Romans. These differences led to very different futures for the two empires, both of which were among the strongest in the world at the time. . The first comparison is that both Han China and Imperial Rome were bureaucracies. They had a sole ruler, but they had many others governing specific portions of the empire. This allowed for the empire as a whole to be in better shape. This is due to the fact that a more localized ruler would better know both the area and its needs. They would also be more dedicated to their job as they would be managing the area they live in, so every decision they make would impact not only their life but possibly the lives of family living in the regions they are governing. The empires would be much worse off if they had their single ruler managing everything, as they would not fully understand the needs of the areas, nor would they care as much as they would most likely have no personal ties to those regions. Due to this, both empires were much more powerful and well organized. Another comparison is that Han China had the civil service exams, while Imperial Rome had nothing similar. The exam allowed for overall better governing and management of the empire. This is because the examination filtered out those who were unqualified for those positions and instead filled them with intelligent people who could do good for the empire. If they let unqualified people in that would greatly increase poor management because they would not be knowledgeable enough to make decisions that would benefit not only that one area, but the empire as a whole. Without the civil service exams, many unqualified people entered positions of power in Rome, and so there were many problems. The final comparison is that Han China had a greater emphasis on religion than Imperial Rome. In Han China, this was found in the mandate of heaven, the structure of family found in the government, and that to get a good job in the government one needed to be educated in Confucianism. When the Han first took power, they incorporated the mandate of heaven into Confucian values, If the ruler was a good ruler, then they were supported by the heavens. Confucianism also led to the family hierarchy becoming the basis for government structure. Subjects owed the emperor the same obedience that they gave to their fathers. Religion was also important because one needed to be knowledgeable in Confucianism to get a good job, as the tests were mainly based off of Confucian texts. Rome, on the other hand, had no real religion within the government. While both Han China and Imperial Rome were different in terms of imperial administration because of Han China’s civil service exam, as well as Han China’s focus on religion, they are still similar due to the fact that they are bureaucracies. Even so, these differences and more led to very different futures for both empires, neither of which ended very well.

Political science as a social science Essay Example for Free

Political science as a social science Essay Political Science is in part a social science, and in part a humanity. Both are important. In this topic, we will look at the basics of social science inquiry, and then proceed to show how this differs from, on the one hand, inquiry in the natural sciences and, on the other, inquiry in the humanities. Social Science Social science inquiry seeks to develop empirical theory. ?Empirical? refers to things that can be experienced through the five senses of seeing, hearing, touching, tasting, or (in the case of political corruption) smelling. Theory? basically means explanation. An empirical theory of politics, then, is an attempt to explain why people behave the way they do politically. If a social scientist (or anyone else) observes people engaging in political behavior, he or she will need to focus on certain characteristics of the people being observed. The observer may wonder why some people differ from others in their political characteristics. Why, for example, are some people Liberals while others are Conservatives and still others are New Democrats. Characteristics that differ from one person to another are called one variables. Those that do not are called constants. Constants are generally less interesting than variables. There is not much point in trying to explain voting behavior in a country in which only one party appears on the ballot. Of course, we might then ask why some countries have only one party whereas others have multi-party systems, but now we are treating ? number of parties? as a variables. Everyday language is full of what are, in effect, hypotheses about political behavior. For example, talk about a ? gender gap? in voting hypothesizes that vote (the dependent variable) is in part a function of gender (the independent variable), with women more likely to vote for the Liberals or New Democrats and men more likely to vote Conservative. Social science research differs from everyday discussion of politics in two ways. The first is where hypotheses come from. Anyone who follows politics will likely carry around in his or her head a lot of ideas about what explains political behavior. Such ideas may come from personal experience, from conversations with others, or from following politics through the mass media. This is true as well for the ways social scientists think about politics. In addition, however, social scientists develop hypotheses more systematically by studying the scholarly literature for the results of previous research. This is important for at least a couple of reasons. For one thing, it is usually the case that the more you learn what is already known about a subject, the more new questions you are likely to have. A review of the literature helps generate new hypotheses. Even more important, social science seeks not merely to describe raw facts, but to explain why people behave the way that they do. To accomplish this, we need to put our ideas into a broader theoretical context that offers such an explanation. It is a fact that in the United States, from 1936 through 2000, the incumbent party has always won the presidency whenever the Washington Redskins won their last home game before the election, and lost whenever the Redskins lost. However, since there is no reasonable explanation for why this should be the case, it is merely an interesting bit of trivia, and no serious observer of politics would rely on it in analyzing the next presidential contest. A second difference is that, for many people, ideas about patterns of political behavior remain merely assumptions. Social science insists that the validity of assumptions must be tested against data. Conceptual definition. We need to know, and be able to communicate to others, what our independent and dependent variables mean. What, in other words, is the idea in our mind when we use a term? Definitions found in dictionaries are examples of conceptual definitions. Sometimes, the idea that is in our mind when we use a term will be obvious, but often it will not. Many concepts used in political science are anything but clear. If we are to study political ideology, for example, we need to spell out with as much precision as possible what that concept means in the context of our research. Operational definition. For hypotheses to be tested, we will need to come up with measurements of our variables. An operational definition is one stated in a way that can be directly measured by data. We strive for a one-to-one correspondence between our conceptual definitions and our measurements (operational definitions) of them. If we succeed, then our measurements have validity and reliability. Data needed to provide operational definitions of our variables come from a wide variety of sources. We may gather the data ourselves. Analysis of data that we gather in order to test hypotheses that we have formulated is called primary analysis. Often, however, this approach would be totally beyond our resources of time, money, and expertise. A nationwide survey of public opinion, for example, would take months to design and carry out, would cost many thousands of dollars, and would require the services of a large survey research organization. Often, secondary analysis of data (that is, analysis of data originally gathered for other purposes) will suit our needs far better. Indeed, very important databases are used almost exclusively in secondary analysis. The Census Canada data is a good example. Other surveys such as the Canadian National Election Study and the General Social Survey were created, in part, for the express purpose of providing quality survey data for secondary analysis by students of Canadian politics. Indeed much of the work using the Canadian National is based on secondary analysis. To facilitate secondary analysis, the University of Toronto Data Library, and other university-based data archives have been established throughout the world. The largest of these is the Inter-university Consortium for Political and Social Research (ICPSR) established in 1962. Today, over 500 colleges and universities from all over the world, including the University of Toronto are member institutions. Students and faculty at these institutions obtain datasets that provide the basis for numerous scholarly books, articles, and conference papers, graduate theses and dissertations, and undergraduate term papers. The Social Sciences and the Natural Sciences What we have described as the social science method ? the effort to explain empirical phenomena by developing and testing hypotheses ? could as easily be called simply ? the scientific method,? without the ?  social? qualifier. There are, however, differences between social sciences, including political science, and the natural sciences. Though these are differences in degree, they are important. One difference is that the natural sciences rely much more heavily on experimental design, in which subjects are assigned randomly to groups and in which the researcher is able to manipulate the independent varia ble in order to measure its impact on the dependent variable. Often, when people think about the scientific method, what they have in mind are these sorts of controlled laboratory experiments. In political science, we for the most part are not able to carry out experimental designs. If, for example, we wish to study the impact of party affiliation on decisions by judges, we cannot very well assign judges to different parties, but rather have to take the data as they come to us from observing judges in their natural setting. Experimental design, however, does not define the natural sciences, nor does its absence define the social sciences. Astronomy, for example, must of necessity rely on observation of things that cannot be manipulated. ?Epidemiological?  medical research also relies on non-experimental data. Conversely, the social science discipline of social psychology has been built in large part from experiments in small group laboratories. In political science, a great deal of laboratory research on the impact of campaign commercials has been carried out in recent years. Field experiments are also common, as when survey researchers will test the impact of alternativ e question wordings by splitting their sample and administering different questionnaire forms to different subsets of respondents. Nevertheless, it is fair to say that experimental designs are much less common in the social sciences, including political science, than in the natural sciences. Most of our research design is, in effect, an effort to approximate the logic of experimental design as closely as possible. Other differences, also differences in degree, have to do with lower levels of consensus in the social sciences. There is less consensus about conceptual definition. Even if we agree that power is a key concept for the study of politics, we may not agree on what power means. Chemists, on the other hand, not only agree that molecules are important, they also mean pretty much the same thing when they use the term. There is less consensus about operational definition. Chemists also agree on how to measure the atomic weight of a molecule. Social scientists are far from unanimous in the ways they go about measuring power. It bears repeating that these differences are ones of degree. In the natural sciences there are also disputes at the frontiers of the various disciplines about what concepts are important, what they mean, and how they should be measured. In the social sciences, consensus is likely to break down from the start. Even if we can agree that a particular concept is important, on what it means, and on how it should be measured, we will encounter far larger problems of measurement error than those in the natural sciences, where measurement is not without error, but is typically much more precise. Finally, remember that we are involved in trying to explain human behavior. People do not seem to behave as predictably as molecules. Philosophers are not in agreement on this point, but it may be that human behavior is inherently less predictabl The fact that we deal with tendencies rather than with laws means that, for the most part (and despite impressive work by ? rational choice? theorists to develop formal mathematical models of political behavior), political science makes relatively little use of elegant systems of deduction, but considerable use of statistics, which provides us with valuable tools for dealing with probabilities. Despite its unavoidable limitations, political science as a social science has produced an explosion in our knowledge about politics. This has had important practical consequences. For example, no serious aspirant for a major elected office in an economically developed democracy would consider embarking on a campaign without consulting experts in survey research, a signature social science technique. In addition to being, in part, a social science, political science is also in part a humanity. Political science as a humanity means at least a couple of different things.

Basic Structures Of Ferrous Metals

Basic Structures Of Ferrous Metals Ferrous metals is mainly based on iron-carbon alloy with the combination of other alloys such as plain carbon steels, alloy, tools steels, stainless steels and cast iron. Alloys having iron with a valance of +2 are known as ferrous; those alloys which have iron with a valence of +3 are called as ferric. Ferrous metals or alloys are metals that contain the element iron in it. Depending on the end of use, metals can be simply cast into the finished part or cast into an intermediate form, such as an ingot, then worked, wrought by rolling, or processed by forging, extruding or another deformation process. All ferrous metals are magnetic. They contain a small quantity of other metals in order to give the correct properties. Manipulation of atom-to-atom relationships between iron, carbon and various alloying elements establishes the specific properties of ferrous metals. As atoms transform from one specific arrangement, or crystalline lattice, to another its gives good mechanical propertie s. Pure iron: It is also called as Pure Ferrite. The carbon content is calculated. From 0 to 0.5%.It has the BCC structure when it is in room temperature. Also known as Alpha iron. Plain Carbon Steel: Consists of iron containing small amounts of carbon. The carbon content can vary from 0.008% to approximately 2.0%. Low- Alloy steel: Steel containing alloy additions which usually do not exceed a total about 10% are referred to allow-alloy steels Ultra-High-Strength steel: Steel capable of developing yield strength greater than about 1104 Mpa are considered ultra-high-strength alloys. Medium-carbon low-alloy steel: These alloys consists of grades such as 4130,4330 and 4340, which can be quenched and tempered to yield strengths on the order of 1725 Mpa Maraging steel: This class of steel consists basically of extra-low-carbon (less than 0.3%) iron-based alloys to which a high percentage of nickel has been added. Corrosion-Resistant (stainless) steel: Stainless steel may be divided into four categories: ferritic, martencitic, austenitic, and age-hardenable. Ferritic stainless Steels: This group of stainless steel contains between 11.5 and 27% chromium as the only major alloying element in addition to a maximum of 0.25% carbon Martensitic stainless steels: This type of stainless steel is also primarily chromium steel, but in contrast to the ferritic group, consists enough carbon to produce martensite by quenching 0.15 and 0.75% carbons. Austenitic stainless steels: This Stainless Steel is alloyed to the extent that they remain austenitic at low temperatures. The principal alloying elements added to the chromium and nickel, generally totaling than 23% Precipitation-hardening stainless steels: The last class of stainless steel we will discuss depends on precipitation hardening for the optimum development of properties. Very high strength together with corrosion resistance Cast iron: Cast irons are iron-carbon-silicon alloys. More than 2% of carbon Grey cast-iron: Also known as graphite cast iron. They depend on the distribution size and amount of the graphite flakes and matrix structure. Spheroid graphite cast-iron: Also known as Ductile or nodular iron. It has high modulus of elasticity. Austempered Ductile iron: Recent addition to cast iron family, outstanding combination of high strength, toughness, wears resistance. Compacted cast iron: Referred as vermicular iron. Consists of 80% graphite and 20% spherodial graphite Malleable Cast iron: Carbons present as an irregular shaped nodules of graphite. Also classified as white heart malleable cast iron. Blackheart malleable cast iron.Pearlitie malleable cast iron Austentic carbon: They are high alloy cast iron. Mainly nickel in which carbon is present List of advantages These are materials with high specific strengths when compared with weight that is high strength to weight ratio. High quality materials exist in abundant quantities within earth’s crust and are readily available worldwide in various certificate grades. It increases the speed of construction in the field of civil engineering. Versatility;steel suits range of construction methods sequences. Modification repair can be easily done with left effort. Recycling can be done easily. Durability of these materials are very high Aesthetics;steel has a broad architectural possibilities Limitation of the material in engineering applications: The principal limitation of many ferrous alloys is their susceptibility to corrosion Costly waste as scrap High cost of final finishing polishing Environmental issuebecause of improper disposal Ferrous metals get rusted easily (oxidize) unless protected eg. with oil b) Non-ferrous metal Non-ferrous metals are metals other than iron and they do not contain an appreciable amount of iron in them. Non-ferrous metals are aluminum, magnesium, titanium alloys, copper, zinc and miscellaneous alloys like nickel, in, lead, zinc as base metals. The precious metals silver, gold and platinum are also coming under non-ferrous group. Non ferrous metals are alloys which are non magnetic. Non ferrous metals: Aluminum: Abundant element of 8% on earth crust and normally found in Oxide forms (Al2O3), i.e., bauxite, kaolinite, nepheline and alunite Aluminum base alloys: Aluminum is used in its commercially pure state as well as in its many alloy forms. The heat –treatable types have the advantage of being relatively easy to fabricate in their soft condition, after which they are heat treated to develop their higher strengths. Copper- base alloys: Copper is seldom industrially employed in its pure state. Copper has its most value when alloyed with other elements. It dissolves with elements such as tin, zinc, and silver in rather wide proportions. Magnesium – base alloys: Magnesium are noted for their lightness. The specific gravity of magnesium is 0.064 lb per cu.; in comparison, aluminum, steel, and titanium are 0.09, 0.28, and 0.16 lb per cu., respectively. Magnesium alloys lend themselves to welding and filler are protected by an inert gas. They are relatively easy to cast by most foundry methods, particularly die casting. Nickel –base alloys: Nickel is one of the oldest metals known to man. Currently this metal is almost indispensable in the alloying of steels to confer toughness, uniformity of hardness, and good workability; and as a basic alloy to resist high corrosion and high temperatures Lead-Tin alloys: The principal lead –tin alloys consist of solders and bearing materials. The 70% tin -30% lead solder is used mainly in the joining and coating of metals. The 63% tin-37% lead is a eutectic type solder developed primarily for making electrical joints. Zinc-base alloys: Zinc base alloys predominate as die casting materials. These alloys have high cast ability and favorable mechanical and chemical properties. Zinc base alloys can be cast in the range 750-800  º F, and, therefore, have a low –temperature advantage over other alloys Less common metals and alloys: Titanium and its alloys: Because of their high strength- weight ratio, titanium and its alloys have received a great amount of attention from the aircraft and missiles industries. Molybdenum: This element has long been known for its ability to confer the property of high temperature stability to steels. Zirconium: Zirconium metal has a density of 0.24 lb per cu in. And a melting point of 3355 ºF. The metal has fair tensile strength, depending somewhat upon its method of manufacture. It fabricates similar to titanium, and it’s eminently suited to the resistance to corrosion. List of advantages Non ferrous metal do not corrode (aluminum for example) High thermal conductivity High electrical conductivity Non ferrous metals have relatively high density Nonmagnetic properties Higher melting points Resistance to chemical They are also specified for electrical applications They are comparatively low in electrical conductivity Non ferrous have inherent susceptibility to corrosion in some common environment Non ferrous metals are usually light weight but ferrous metals are heavier Limitation of the material in engineering applications They are not as strong as carbon steel (ferrous metal). Non ferrous metals are typically not used in structural applications. Non ferrous metals are usually more expensive by the pound than are ferrous metals. Low tensile strength but excellent specific strength. They don’t show ductile to brittle transition in low temperature. c) Polymers: Compounds that are formed by the joining of smaller layers, usually repeating, units linked by covalent bonds are called polymer. A polymer is a large molecule consists of repeating structural units connected by covalent bonds. Polymer in popular used as plastic; the term polymer refers to a large category of natural and synthetic materials with a wide spectrum of properties. Natural polymers are those which come from plants and animals have been used for many centuries; these materials include wood, rubber, cotton, wool, leather, and silk. Other polymers such as proteins, enzymes, starches, and cellulose are important in biological and physiological processes in plants and animals. The backbone of a polymer used for the preparation of plastics consists mainly of carbon atoms. Polymer in popular used as plastic, the term actually refers to a large class of natural and synthetic materials with a wide variety of properties Polymers: Polymers are classified into several ways, by how the molecules are synthesized, by their molecular structure, or by their chemical family. Linear polymer Any polymer in which molecules are in the form of spaghetti-like chains. Thermoplastics Linear or branched polymers in which chains of molecules are not interconnected to one another. Thermosetting polymers Polymers that are heavily cross-linked to produce a strong three dimensional network structure. Elastomers These are polymers (thermoplastics or lightly cross-linked thermo sets) that have an elastic deformation > 200%. Polymers are classified into three main categories; Thermoplastics: Branched polymer Any polymer consisting of chains that consist of a main chain and secondary chains that branch off from the main chain. Crystalline is important in polymers since it affects mechanical and optical properties. Tacticity Describes the location in the polymer chain of atoms or atom groups in nonsymmetrical monomers. Liquid-crystalline polymers Exceptionally stiff polymer chains that act as rigid rods, even above their melting point. Elastomers (Rubbers): Geometric isomer: A molecule that has the same composition as, but a structure different from, a second molecule. Diene: A group of monomers that contain two double-covalent bonds. These monomers are often used in producing elastomers. Cross-linking: Attaching chains of polymers together to produce a three-dimensional network polymer. Vulcanization: Cross-linking elastomer chains by introducing sulfur or other chemicals. List of advantages Polymers are ultra durable Flexible doesnt rust slow to degrade They can be molded into virtually any shape conceivable can be custom colored in the production stage Polymers are recyclable quite a good electrical insulator and has a low dielectric constant The biggest advantage for PP is its low cost It also has a flexibility in cold whether with ultraviolet stability can be easily repaired from mechanical damage with simple field tools Limitation of the material in engineering applications In the production stage, polymers are susceptible to contamination The least bit of dirt or cross-contamination w/other polymers, and at best the end product is corrupt, at worst the polymers are rendered useless Any variances in heat and timing in the molding process and, again, the final product will be corrupt or useless. lower melting point flammability Elevated temperatures will make any crystalline more isotropic non bio-degradable easily breakable when polymers incorporated with additives are burnt they emit a lot of poisonous gases into the atmosphere improper disposal leads to environmental pollution undergo oxidation and ozonation easily d) ceramics: These are materials that are produced when two materials are joined together to give a combination of properties that cannot be achieved in the original state. Ceramics can be divided into two classes: advanced and traditional. Advanced ceramics consist of carbides, pure oxides, nitrides, non-silicate glasses and many others; while Traditional ceramics include clay products, silicate glass and cement. A ceramic is an inorganic, non-metallic solid prepared by the action of heat and subsequent cooling. Ceramic materials may have a crystalline or partly crystalline structure, or may be amorphous. Agglomerated materials: Concrete: This is one of the oldest agglomerated composite materials to be used for engineering construction, and consists of a mixture aggregate and sand bonded together by the hydrated silicate the gel formed when the Portland cement â€Å"sets† with water. Ratio of aggregate, sand and cement: A very common mix consists of 4parts aggregate, 2parts sand and 1 part cement powder. The water-cement ratio: The water added to the concrete is used in the hydration of the cement itself, and any water in excess of the amount required for setting reactions has a weakening effect upon the concrete. The nature of the aggregate and sand: The bond between the hydrated cement and the aggregate and sand is improved if the both the aggregate and sand are sharp-cornered rather than rounded. Strong fine-grained igneous rocks like basalt, dolerite, and quantize are commonly used for concrete aggregate, the size of which varies with the size of the job. Mixing and laying: Under-or over-mixing gives a poor concrete, and the method of lying is of the utmost importance. Concrete vibrated into place is always stronger than concrete poured and hand-screwed Curing time: The hardening of cement occurs over a considerable length of time and it is important to prevent the evaporation of moisture .during the initial stages. Concrete is often covered with wet sand or bags for seven days to prevent the evaporation of moisture, and concrete cured under water after taking its initial set achieves its maximum strength. Asphalt paving: This is composite in which rock aggregate is bounded by viscous asphalt: it is used extensively for road surfacing. The material is not as rigid as concrete, this being an advantage for road construction. Cermets: These are agglomerates that consist of combinations of metal and ceramics, the metal acting as the binder. Cermets are made using the techniques of powder metallurgy, the sintering temperature usually being above the melting point of the metal powder. Laminates: Many different types of laminated materials are made of different applications, the mild-steel-stainless combination being a good example of a modern metal-to-metal laminate. Plywood: This is made by bonding together an odd number of sheets of wood veneer so that the grain directions of alternate sheets are perpendicular to each other. Laminated plastic sheet: This is usually made from sheet of paper or cloth and a suitable thermosetting resin. The paper or cloth passes or cloth passes through a tank containing the resin solution, between rollers that squeeze out the excess resin, and then through a drying oven in which excess solvents are removed and the resin is partially cured. Reinforced Materials: It forms the biggest and most important group of composite materials, the purpose of reinforcement always being the improvement of strength properties. Reinforcement may involve the use of a dispersed phase, or strong fiber, thread, or rod Reinforced concrete: This is the most widely used of all construction materials, since it is not only comparatively easy to place into position and finish, but is also maintenance free during its service life. Glass-fiber reinforced plastics: These combine the strength of glass fiber with the shock resistance and formability of a plastic. The usual types of reinforcement are the chopped strand mat and the woven fabric, the latter giving increased strength to the composite. List of advantages They are harder and stiffer than steel more heat and corrosion resistant than metals or polymers less dense than most metals and their alloys plentiful and inexpensive doesn’t conduct electricity Ceramics are used in the manufacture of knives. The blade of the ceramic knife will stay sharp for much longer than that of a steel knife, although it is more brittle and can be snapped by dropping it on a hard surface Ceramic engines are made of lighter materials and do not require a cooling system and hence allow a major weight reduction Ceramics are also more chemically resistant and can be used in wet environments where steel bearings would rust High-tech ceramic is used in watch making for producing watch cases scratch-resistance In very high speed applications, heat from friction during rolling can cause problems for metal bearings; problems which are reduced by the use of ceramics Durability and smooth touch. ceramic materials may be used as bone replacements Limitation of the material in engineering applications The main disadvantage of medical ceramic materials is their fragility The ceramic materials cannot deform under the stress, as can do plastics and metals Ceramics do not perform well with tension or tensional loads. A hard, brittle material that can withstand high temperatures and resist corrosion Ceramics cannot be joined (and repaired) by welding. The other disadvantage is that ceramics are strong in compression, but weak in tension Ceramics dont bend much, and when they break, instead of slowly pulling apart the way metals will, they generally snap they have a tendency to shatter when something hits them hard Q-2 An overview of the engineering properties and behavior of ferrous metals, Non-ferrous metals, polymers composites, and ceramics a) Ferrous metals. Pure iron: Easily weld able, good corrosion resistance, effective electrical conductivity. Used in iron rods Plain Carbon Steel: Expensive, soft and weak, easily weld able, good ductility, Good toughness. Used in hammers, chisels, a drill, knives, wire and dies for all purposes. Low- Alloy steel: Machinable, ductility of more, than 25%. Used in transportation, agriculture, construction, and military applications. Ultra-High-Strength steel: Ductile, Formable, and Machinable. Has higher strength that other steel. Mainly used in Bridges, towers, and pressure vessels. Medium-carbon low-alloy steel: Has low Harden ability. Used in rocket motor cases, aircraft components, including bolts, pins, main landing gears, and brake housings, and a wide variety of structural and machinery parts. Ferritic stainless Steels: Good resistant to wear and tear, highly ductile. Tensile strength – 380Mpa, Yield strength 205Mpa, Ductility 20%, High tensile strength. Good corrosion resistant. Used in furnace parts, boiler baffles, kiln linings, stack dampers, chemical processing equipment, automobile trim, catalytic converters, and decorative purposes in general. Martensitic stainless steels: Tensile strength 485Mpa, Yield strength 275Mpa. Used in cutlery, surgical instruments, valves, turboine parts, pump parts, and oil well equipment. Austenitic stainless steels: Outstanding resistance too many types of corrosion and erosion. Superior cast ability, Good mach inability, and Tensile strength 515Mpa, and Yield strength 170Mpa. Used in decorative purposes, interior show cases, automobile trim, aircraft is fitting, food handling. Precipitation-hardening stainless steels: Very high strength towards corrosion and resistance. Used for aircraft parts, nuclear reactor components, landing gear parts, high-performance shafting and petrochemical applications requiring stress corrosion resistance. Grey cast-iron: Ease of melting and casting process. Air-cooled cylinders clutch housing clutch plates. Spheroid graphite castiron: Modulus of elasticity, Wear resistance, excellent machinability, High thermal conductivity, Outstanding cast ability. Austempered Ductile iron: Higher tensile strength, higher ductility, Machinability and corrosion resistance are similar to g.c iron. Automotive and agricultural products like Axle housing, brake calipers, brake cylinders. Boiler segments, conveyor frames, bulldozer parts. Compacted cast iron: Good wear resistance used in automotives and engineering applications. Used in shafts, helical gears, couplings, and conveyor rollers. Malleable Cast iron: Higher tensile strength ductility. Fatigue life impact strength. Brake drums, discs. Cylinder heads piston rings. Used in Automotive transmission parts, clutch pedals. Steering knuckle, wheel hubs. Austentic carbon: Good fatigue strength, good damping capacity. Used in pump components valves, compressors. Alloy steels have greater harden ability than plain carbon steels Alloy steel have greater harden ability than plain carbon: The difference between the two is somewhat arbitrary definition. However, most agree that while the steel alloyed with more than eight percent of its weight of other elements besides iron and carbon steel is a strong ally. Low alloy steel is slightly higher. The physical properties of these steels are modified by other factors, making them more hardness, strength, corrosion resistance or hardness compared to carbon steel. For these properties, these alloys are often heat-treated. Carbon steel is steel that does not contain significant amounts of alloying elements other than carbon. There are three major categories of carbon steel. A low-carbon steel, medium carbon and alloy. Alloy steel is a type of steel that many advantages over steel offers. It is much harder and stronger than ordinary carbon steel by. It is used in cars, trucks, cranes, bridges and other structures can handle a large number of strains The difference between the two is defined somewhat arbitrarily. However, most agree that while the steel is alloyed with more than eight per cent of its weight of other elements being next to iron and carbon steel is strong ally. low alloy steels are slightly more frequent. The physical properties of these steels are modified by other elements, giving them a greater hardness, strength, corrosion resistance, or hardness compared to carbon steel. To achieve these properties, these alloys often require heat treatment. Carbon steel is a steel which does not contain significant amounts of alloying materials other than carbon. There are three major categories of carbon steel. low carbon steel, medium carbon steel and alloy. Alloy steel is a type of steel that offers many advantages over steel. It is much harder and stronger than ordinary carbon steel by. It is used in cars, trucks, cranes, bridges and other structures to be able to handle a large number of strainsThe difference between the two is defined somewhat arbitrarily. However, most agree that while the steel is alloyed with more than eight per cent of its weight of other elements being next to iron and carbon steel is strong ally. low alloy steels are slightly more frequent. The physical properties of these steels are modified by other elements, giving them a greater hardness, strength, corrosion resistance, or hardness compared to carbon steel. To achieve these properties, these alloys often require heat treatment. Carbon steel is a steel which does not contain significant amounts of alloying materials other than carbon. There are three major categories of carbon steel. low carbon steel, medium carbon steel and alloy. alloy steel is a type of steel that offers many advantages over steel. It is much harder and stronger than ordinary carbon steel by. It is used in cars, trucks, cranes, bridges and other structures to be able to handle a large number of strainsThe difference between the two is defined somewhat arbitrarily. However, most agree that while the steel is alloyed with more than eight per cent of its weight of other elements being next to iron and carbon steel is strong ally. low alloy steels are slightly more frequent. The physical properties of these steels are modified by other elements, giving them a greater hardness, strength, corrosion resistance, or hardness compared to carbon steel. To achieve these properties, these alloys often require heat treatment. Carbon steel is a steel which does not contain significant amounts of alloying materials other than carbon. There are three major categories of carbon steel. low carbon steel, medium carbon steel and alloy. Alloy steel is a type of steel that offers many advantages over steel. It is much harder and stronger than ordinary carbon steel by. It is used in cars, trucks, cranes, bridges and other structures to be able to handle a large number of strainsThe difference between the two is defined somewhat arbitrarily. However, most agree that while the steel is alloyed with more than eight per cent of its weight of other elements being next to iron and carbon steel is strong ally. low alloy steels are slightly more frequent. The physical properties of these steels are modified by other elements, giving them a greater hardness, strength, corrosion resistance, or hardness compared to carbon steel. To achieve these properties, these alloys often require heat treatment. Carbon steel is a steel which does not contain significant amounts of alloying materials other than carbon. There are three major categories of carbon steel. low carbon steel, medium carbon steel and alloy. Alloy steel is a type of steel that offers many advantages over steel. It is much harder and stronger than ordinary carbon steel by. It is used in cars, trucks, cranes, bridges and other structures to be able to handle a large number of strainsBottom of Form b) Non ferrous alloys Aluminum: Weak and ductile, Electrical conductivity is better. High thermal conductivity, Good resistance towards corrosion. Used in Aircraft, boats, pistons and cranks. Aluminum base alloys: copper has high electrical and thermal conductivity. Tensile strength and hardness can be improved. Used in Power lines, controllers, signaling devices. Miscellaneous copper base alloys: Electrical conductivity of 60%, Good corrosion resistance, has the Hcp structure. Used in applications like Aircraft and Spacecraft. Magnesium – base alloys: Has the melting point of 1455’C. Good formability. Good Corrosion Resistance. The pure Zinc has the melting point of 419’cIt has two types of alloys; Alloy A Good ductility Alloy B- Higher effective strength. Used in Petroleum industry, Chemical industry Food processing plants, Fuel pump, optical instruments, car doors etc. Lead-Tin alloys: Excellent corrosion resistance, Good strength. Resistant to high temperatures. Some important types of alloys, alpha titanium alloys, near alpha titanium alloys, Alpha-beta titanium alloys, Beta titanium alloys. Used in Compressor blades, Engine forging and space craft’s. Differences between non-ferrous alloys in the cast vs. wrought forms Nonferrous Alloy Specified for use in electrical and electronic applications. Reduced weight Higher strength Nonmagnetic properties Higher melting points Resistance to chemical and atmospheric corrosion. A type of cutting material is relatively expensive and must be directly casted into the form. Non-ferrous cast alloy tools have largely been replaced by carbide. Wrought alloy: Solid metal that has been bent, hammered, or physically formed into a desired shape. Wrought copper alloys can be utilized in the annealed, cold-worked, stress-relieved, or hardened-by-heat-treatment conditions, depending on composition and end use. Bronzes comprise four main groups: copper-tin-phosphorus alloys (phosphor bronze) copper-tin-lead-phosphorus alloys (leaded phosphor bronze) copper-aluminum alloys (aluminum bronzes) copper-silicon alloys (silicon bronze) Wrought copper-nickel alloys, like the cast alloys, have nickel as the principal alloying element. The wrought copper-nickel-zinc alloys are known as nickel silvers because of their color. c) Polymers: Polymers are classified in various way

feminaw Feminist Reading of Kate Chopins The Awakening Essay examples

A Feminist Reading of The Awakening The Awakening is not new to me. However, in the class when I read it before the instructor refused to entertain a feminist criticism. The theory presented was that Edna knew what kind of man she was marrying and all these things she went through: her friendship with Madame Reisz leaving the house, entertaining her friends at the party, her situation with Robert and Arobin were all selfish efforts toward the ultimate freedom which is death. I feel Chopin faults Leonce as much as Edna for Edna's problems. He is a cold fish. He is controlling and he puts on a show for friends and neighbors "proving" he is a model husband which he is not. He is Creole and I think Edna, being as reserve as she is, is not the best mate for him. He possibly needs an outwardly passionate woman to keep him interested and alive as a husband. For a Creole he is reserve and he does not know how to respond to Edna's reserve. By the end of chapter V we know the Pontelliers have problems and we know Robert is sympathetic towards Edna merely because she is a woman and he likes women. We have also seen the "ideal" woman in the person of Madame Ragtignolle. Chapter VI is very different. Chopin lets us know that Edna has begun to realize her world and its relationships are less than desirable. She and Leonce don't have a happy, fulfilling marriage. She is not the mother-earth type and can not appreciate her children. Although, some of the problem here is because Leonce undermines her mothering efforts and has done so from the beginning. His mother epitomizes motherhood and no one can measure up. I doubt she would have been a demonstrative mother but she would have been a loving one. The last paragraph of Ch... ... the very end of the story just before Edna enters the ocean for the last time End watches the coast. There is no living thing all along the beach, but there is a bird, a wild free bird, with a broken wing who †was beating the air above, reeling, fluttering, circling disabled down, down to the water .† Even the wild birds need support. End had no support, just like this bird and her fate is the same â€Å"down, down into the water.†I’m hung up on the lack of communication between Edna and Leonce. I wonder if Leonce has a comparable story of misery. In the first several chapters Edna says four lines and they are in response to someone or something else. They are not ideas originating with her. Leonce’s words to Edna are aimed at control. He goes off to the hotel and says he’ll be back whenever This leaves her waiting for his next move, his next demand (request).

Traditional and Internet Dating Essay -- Dating Social Values Changes

Traditional and Internet Dating At some point in our lives where we are searching for that special someone. The methods of going about dating have changed quite dramatically over the years. Going out has grown from traditional dating, to internet 'dating', to group dating.   Ã‚  Ã‚  Ã‚  Ã‚  Traditional Dating has changed over the years. In my generation the girls can ask the guys, there is no telling where they might go on a date, or they might just hang out at home, which did not happen as much 25 years ago. My generation's moral values are changing too: sex on the first date happens more frequently now. Many Years ago a guy would go pick the girl up at her house, was introduced to her parents and have a talk with them before taking their little girl out for a first date. Now, however, guys and girls meet somewhere or the guy just beeps the horn and in many cases the parents do not meet the guy with whom their daughter is going out. When my parents were young, dating was something taken seriously, and knew someone for a period of time before ever asking her out on a date. Today a date may be just something to do for fun or if you are bored. Nowadays many people "hook-up" at bar, clubs or random parties. : I wonder what changes are to be in the futur e of dating.   Ã‚  Ã‚  Ã‚  Ã‚  What kind of person goes online and uses personal ads to meet their mate. The Internet changing everything from the way we shop to the way we find driving directions. Cyberspace has become the hottest pick-up jo...

Titanic Essay examples -- essays research papers fc

TITANIC This paper will be about the sinking of the R.M.S. Titanic. Some people call this sinking the greatest maritime disaster. It wasn't just the fact that the ship sank, but also all the different circumstances that caused this ship to sink and take so many lives. In the time period of 1900's-1915's many things happened. One major disaster was the sinking of the Titanic. The information will be gathered from the library, a documentary film, the Internet and personal books. From these resources the paper will explain about how the Titanic sank, some of the people who were on the ship and how it was found after over 70 years at the bottom of the Atlantic. People who read this paper should learn about the history of the Titanic. The Titanic was originally designed to have three funnels, but four were used to make it look better. The fourth funnel was actually just an air vent. The main dining room was supposed to have a large dome but it was changed to a normal ceiling. The staircase was enlarged so it fanned out at the landing of each deck, as well as adding a large glass dome above it. Also, two extra elevators were added making a total of four. "She was the most beautiful ship afloat. No ship will ever resemble her class and luxury." ("R.M.S Internet") The R.M.S. Titanic was believed to be unsinkable. Bruce Ismay was the White Star Line chairman on the Titanic; he told the captain that the ship was unsinkable because the ship could have any four watertight compartments damaged and still stay afloat. He also believed that anything big enough to sink this ship, could be seen from miles away and be avoided. Mr. Ismay said, " Not even god himself could sink this ship." ("Titanic" Internet) Originally the plan called for 64 lifeboats but only 20 lifeboats were used. There were 14 wood lifeboats that could hold 65 people each. Two woodcutters that could hold 40 people each and four collapsible boats that could hold 40 people each. These lifeboats would only be able to hold about half of the passengers in an emergency. ( Internet) Knowing the lifeboats would only be able to hold about half of the passenger's, crewmembers still only filled some of the boats with less then 30 people. These boats were hal... ...e think that they should raise the Titanic so that they could explore it and study it. I think they should leave it where it is, out of respect at least. People lost their lives on this ship and deserve a place to spend their time. Not only will they disrespect the dead, but also by raising the ship, they will disrupt everything. Once the steel hits the oxygen, it will begin to corrode. After awhile, there will be no Titanic left at all and just so they could study it. " The Titanic surely should never be raised, it is a cemetery to all those who lost their lives that nite."(Ballard "Long" 708) WORKS CITED Ballard, Robert D. "How We Found Titanic." National Geographic (December 1985): 696-718. Ballard, Robert D. "A Long Last Look at Titanic." National Geographic (December 1989): 698-727. "R.M.S. Titanic†¦the story told." Internet. http://www.titanic.cc/titanic.htm. (4 Feb. 2001). "The Titanic Tragedy." Internet. http://www.angelfire.com/ct/titanickateleo/page11.html. (4 Feb. 2001).

Loa Loa Essay

Loa Loa â€Å"African Eye worm† [pic] [pic] Loa Loa By Amanda Green Microbiology 210 Loa Loa is a parasite known more commonly as the â€Å"African Eye Worm†. This may be one of the most feared of the parasites. They are classified as filarial worms, meaning they thrive in human tissues. Before the 1920’s , Loa Loa infections occurred more frequently in the United States now it is more commonly found in West Africa and equatorial Sudan. It prefers areas with hot, wet climates, like swamps and rainforests. They are cylindrical and have a cuticle with three main outer layers. This protects the nematodes (larvae) so they can invade the digestive tracts of animals. The outer layers are non cellular. The adult Loa Loa is a thin small worms ranging in length from 20 – 70 mm long and 350 – 430 mm wide. Males are smaller than the females. Loa Loa was first described in 1770 by a French surgeon, Mongin. He was the first surgeon to try to remove a worm from the eye of a woman in Santa Domingo. He was unsuccessful. Another observation came form a French ships surgeon, who observed an eye worm in slaves being taken to the West Indies from Africa in 1778. The first person to identify the microfilaria of Loa Loa in 1890 was Dr. Patrick Mason when he was invited to examine blood smears with Dr. Stephen Mackenzie. This person was thought to have â€Å"sleeping sickness of the Congo. † To reproduce the female produces a pheromone to attract males. After mating the female produces large numbers of active embryos called microfilaria. These microfilaria find their way to the blood stream where they can be transmitted through a bite to the next host. Loa Loa is an obligate endoparasite that feeds on fluids in the tissues of humans. The parasite contains pharyngeal glands and intestinal epithelium that produce digestive enzymes that enable them to feed on the hosts’ body fluids. Extracellular digestion begins within the lumen and is finished intracellularly. The adult parasite has been known to live up to 15 years. A human infected by Loa loa is termed Loiasis. People become infected by the transmission by deerflies. Once the deerfly lands on the host and bites, the larvae then drops into the opening of the skin and burrows into the subcutaneous tissues. The larvae then migrate through the body, commonly to the eye. They congregate in the lungs at night. Damage can be done to the eyes as it crawls through the cornea and conjunctive tissues. It can easily be seen and felt in the eye up to an hour. When they are deeper into the body they can cause encephalitis, if they reach the brain, which can lead to death. Joint pain can occur from swelling if the parasite stays near a joint for a period of time. The larva can remain unnoticed for months or years before becoming an adult, mating, and producing offspring. They continuously travel through deep and connective tissues, often even without the person feeling any sensation other than occasional itching. A person may feel the greatest discomfort when the worm slows or reaches a sensitive spot. It is then that the immune reaction starts, with localized redness and swelling called Calabar. This type of reaction is thought to be caused by a type of allergic reaction to dead worms and their byproducts. Skin eruptions and muscle pain may be evident. Once the worm dies the surrounding tissues may abscess. An accumulation of serous fluid in a sacculated cavity called hydrocele is a less common symptom. Colonic lesions, fibroblastic endocarditis, membranous glomerulonephritis, retinopathy, arthritis, and peripheral neuropathy can occur but are less common in people native to endemic areas. To diagnose Loasis, physicians look for Calabar swelling and the presence of worms in the conjunctiva. Those are the main tests used to diagnose an infestation. Some laboratory tests can help with the diagnosing including, C – reactive protein, elevated eosinophils (called eosinophilia), and IgE quantification. Identification of microfilariae by microscopic examination is the most practical diagnostic test. The collection of the blood specimen is extremely important with the known periodicity of the microfilariae. The smear is stained with Giemsa or hematoxylin and eosin. Concentration techniques can be used for increased sensitivity, including centrifugation of the blood sample hemolyzed in 2% formalin. Checking for microfilaria in the blood on a newly suspected case is not recommended because it can take may years for them appear. Loa Loa is endemic only to parts of West Africa. A study done by S. Wanji at the University of Boea in Cameroon found that in 16 rural villages in southern Cameroon 2. 2% to 19. 23% of people were infected. It also showed that males are almost twice as likely to become infested as females. The level of infection increases from the ages of 15 to 65 years old and then drops. The treatment’s side effects for Loa Loa are more life-threatening than the actual infestation. Two of the most common treatments are diethylcarbamazine and ivermectin. Both of thes e treatments can cause encephalitis, coma, or death in people with high microfilaria loads. These drugs kill the microfilaria but not the adult worms. Other treatments include chemotherapy and surgical removal.