Investment casting Essay Example

Investment casting Essay Investment casting or lost wax casting has been used by many different cultures for thousands of years.The Egyptians used investment casting to make bronze statues and the Chinese made vessels and a variety of other items by using investment casting.Therefore, it is by no means a new process.The most modern approach, which has been used since the middle of the twentieth century is called ceramic shell casting.Because this is the most modern form of investment casting, I will bee focusing on this particular process for the entirety of the paper. The two different types of patterns used in investment casting are called expendable and permanent.Expendable patters are made of wax, are joint less, and yield a casting with a higher degree of accuracy than the permanent pattern method.The permanent pattern method uses a pattern that is made of wood, steel, or some other type of solid material.Using the permanent pattern method is usually cheaper than the expendable pattern method.One disad vantage of the permanent pattern method is that the molds must be assembled in separate parts, which makes it less accurate than the expendable pattern method. Thefirst step in investment casting when using the expendable pattern method is to manufacture a die.The die is made from strong alloys such as steel and Duralumin or softer fusible alloys where accuracy is less important.Steel dies are the best for long production runs and are machined from a solid piece of steel.Many dies are produced in two or more sections enabling the pattern to be removed once it is cast.After the die is done being machined it is coated with a parting agent or lubricant which helps the pattern to be extracted.The die is used repeatedly to makewax patterns for the investment process. Wax is the most common material used in investment casting.The wax has a low ash content, is compounded from natural and synthetic waxes and resins, and usua

Crucial Features of DBQ Essays

Crucial Features of DBQ Essays You may think that writing a DBQ essay is a very difficult task but it only looks so scary. If you want to pass the AP exam, you must know what you’ll be going through. As soon as you learn more about DBQ essays, you will realize that you certainly can deal with it. DBQ, which stands for Document Based Question, is a type of essay that is often required for AP exams as well as for history exams both in the US and Europe. Being a â€Å"document-based question,† this essay implies several underlying documents on a certain subject. Your task is to consider the relationship between these documents, tendencies that appear in documents during some period of time, and other details. In addition, you cannot just describe these features of documents. You need to provide an accurate analysis of sources. DBQ essays are also somewhat similar to cause and effect essays because you need to explain the flow of events and relationships between them. Many students are confused by the fact that DBQ essays are quite different from free-response essays, while in fact there’s nothing special about this task. Check our useful guide and write your DBQ essay following simple steps. How to Write a DBQ Essay If you want to write a good DBQ essay, there are only two things you must know. First of all, you must be able to plan your work properly. If you plan your work in advance, you can be more confident and use advanced methods of writing. In addition, you will easily cope with your AP exam if you practice a lot. Follow our advice and work on your writing skills! Usually, you have only 55 minutes to complete the DBQ essay for the AP exam. Sometimes this limit may vary but, most often, you have 15 minutes to read all necessary materials and 40 minutes to write your paper. However, 15 minutes of reading means that you must also spend some time on understanding your question, generating ideas for the essay and processing new information. You may want to start writing earlier but even if you have a couple free minutes, we suggest taking your time and planning the structure of your essay. Time management is especially important, since the essay isn’t the only task of the AP exam. Read your question. Not only should you read it, but you also must understand it. Note some important data that may be useful when writing the essay. Jot down facts that you must mention and underline your key tasks. After this, quickly write a few thoughts related to the question. You don’t have time for proper brainstorming so make sure to use a couple minutes that you have. Analyze documents effectively. You may need to work with many different documents and you will need to provide a good analysis. We suggest considering it an opportunity rather than a challenge, because a proper analysis also provides you with necessary evidence for supporting your ideas. There are many kinds of documents that can be used in AP exams, such as speeches, letters, legislative documents, maps, articles, and even pictures. Sometimes you must analyze some classic documents that you certainly have heard of, though they will not sound familiar to you. First of all, pay your attention to the author of the document and to the time when it was published. Jot down key ideas of this text. After noting important points, get to the questions about this document. Don’t forget to write notes ? this is how you save your time because otherwise you will need to return to certain parts of your sources and re-read them. Ask yourself a couple additional questions, for example, can these documents be divided into some groups? What are they based on? Develop your thesis statement. Make a draft of your thesis statement and draw up an outline for your essay. If you already know something interesting about the topic of your task, this information may also be useful in the future. Think about the structure of your essay, and make it so that every paragraph of the essay will consider a particular idea. Write an essay. Your goal is to write a meaningful text based on a strong thesis. Each paragraph must provide examples and facts related to your question. You also need a conclusion, however, let’s take a look at the whole writing process from the beginning. An introduction of a DBQ essay is no different from this of any other essay. You must introduce your topic, provide your readers with necessary background information on this subject, briefly describe your main points, and come up with a thesis statement. Try to focus on the purpose of your paper. A body section includes one or several paragraphs, each one of which focuses on one idea and supports it with evidence. Start every paragraph with a topic sentence so that it will reflect the overall structure of the essay. If you have divided your documents into several groups, you can devote every paragraph to a certain group of sources. Include more documents so that you will have more evidence for your arguments. You should not just describe documents, in fact, it is the worst thing you can do. Make proper references and include parts of sources in your essay. On the other hand, always make sure that all documents that you include are directly related to your thesis statement. The conclusion is aimed to remind your readers the purpose of the essay and provide them with a concise summary of everything written before. Another important feature of the conclusion is that it can address more global issues. We suggest taking this opportunity to make your paper more meaningful. Ask yourself, why is this topic so important? Think about it in a global context. If you realize that you’re running out of time, write at least one concluding sentence. It’s much better to conclude your essay briefly than if you don’t conclude it at all. Proofread your essay. We know that 55 minutes is not enough time for proper proofreading but we suggest doing this. Plan at least a few minutes to read your essay, to fix all mistakes, and to check such specific details as places, dates, and names. Tips on Writing DBQ Essays Make sure that you understand the question well, as your main goal is to answer it correctly. Unless your assignment has such requirements, don’t dig into the historical background. When mentioning documents in text, don’t refer to them as â€Å"document 1† or â€Å"document 2.† Instead, write the whole title of a source. You may or may not be allowed to use quotes in your essay, however, DBQ essays often benefit from citations because you can clarify what source you are talking about. Anyway, don’t forget to write your quotes according to a required format. Check the paragraph structure and make sure that all your thoughts are presented in a logical order. Keep in mind that sometimes, there’s no right answer to the topic question. Thus, you are allowed to consider any points that you can support with evidence. In order to increase the credit for your paper, you can use outside information. Don’t get too emotional about your exam and don’t panic! To feel confident on the exam, learn more about it, read examples of DBQ essays on the internet, and prepare. Don’t forget that your readers can be too limited in time to consider your essay in details. Thus, it’s important to create a good overall picture of your work. On the other hand, it doesn’t mean that you shouldn’t work on details. DBQ essays often focus on such issues as art, science, and religion. Therefore, we suggest getting acquainted with methods of writing historical essays. The most important thing about writing DBQ essays is to stay calm. Sometimes students spend a lot of time preparing but fail their exams just because they panic. Even if you think that this task is hard, it doesn’t mean that it’s impossible to complete. Thus, just focus on your goal and prepare for your DBQ exam in advance.

Western civilization. Industrial Revolution and Political Theories Essay

Western civilization. Industrial Revolution and Political Theories - Essay Example According to Montagna (2009), industrial revolution happened from 1750 to 1850 beginning in the United Kingdom spreading to Western Europe, Japan and North America. The industrial revolution was a major turning point in history. This marked the first time in history where living standards of ordinary people underwent sustainable growth. There are some innovations that are regarded to as the origins of the industrial revolution. These discoveries were in metal industry, textiles and the discovery of steam power (Montagna, 2009). Innovations in the textile industry included; the spinning jenny by James Hargreaves, the water frame by Richard Arkwright and the spinning mule by Samuel Crompton. These three sectors paved way for the industrial revolution. Before the revolution, wool was the major raw material in the textile industry. After these innovations the textile industry grew remarkably, since the exploitation of other raw materials like cotton was possible. Replacement of tradition al fuels like wood with coal saw a major change in the metal industry (Montagna, 2009). The coal produced a lot of heat and carbon monoxide reducing oxidation. Coal was a good fuel since impurities which were contained in it, did not migrate to the metal. This resulted in the iron industry growing remarkably. The stationary steam engine also paved way for the industrial revolution. ... This caused many children to find jobs in factories where they were paid very little income. The industrial revolution also resulted in high crime rate and social evils. As a result of high population, many people ended up jobless. This prompted them to engage in crime and other social evils such prostitution in order to earn a living. The industrial revolution also had an impact on the social class structure (Montagna, 2009). It resulted in the rise of middle class businessmen who rose above the noble class who owned large tracks of land. It also saw an increase of low class citizens who worked for minimum wages in the factories. The industrial revolution saw the development of good housing for the owners of the factories and very poor housing for the workers and laborers. Industrial revolution also resulted in poor health in the society. This was as a result of air, water and land pollution from the industries. Factories dumped toxic materials in land and water bodies which were in turn absorbed by people through food and drinking water. Many workers also suffered from lung diseases from the fumes which were present in the factories. The industrial revolution saw the emergence of workers unions and trade unions to fight for the rights of the workers. Most employer laws that we have today were as result of these trade unions. Lesson 8: Political Theories In this part of the assignment I will use Delacroix Eugene’s painting â€Å"Liberty Leading the People (28th July 1830)†. Source: Olga’s Gallery (2012) This painting is used to depict the celebration in 28th July 1830, where the people decided rise and dethrone king, replacing him with Louis