Engineering Materials Essay on Polypyrrole Essay Example for Free

Engineering Materials Essay on Polypyrrole Essay 1.0 Introduction to Polypyrrole The reason of this report is to determine the effects of temperature on the thermal, physical and mechanical properties of Polypyrrole. And then conclude the possible applications of this polymer according to its properties. Known as the conducting polymer, it is a black insoluble material according to Richard Doyle (2011), usually in the form of a thin film. It was the first polyacetylene-derivative to show high conductivity. Over the years it has become one of the most studied and extensively applied conducting polymer due to the reason being that it can be easily prepared, has high conductivity and has relatively greater stability amongst other heteroatom containing polymers. It is made up of monomers that are amines attached to aromatic rings. Some of the physical properties of Polypyrrole, as mentioned on WolframAlpha (2011), it has a Melting Point temperature of  573.15K and as identified by T.F. Otero, J.J Lopez Cascales and G Vazquez Arenas. (2005), Young’s Modulus was found to be of 310 MPa. The Glass Transition State, as indicated by P. Syed Abthagir and R. Saraswathi (2004), in their report Thermal stability of polypyrrole prepared from a ternary eutectic melt, was found to be 545k. 2.0 Methodology of the simulation tests In order to determine the effect of Temperature on Polypyrrole, simulations were carried out using the simulation software called Materials Studio. 2.1 Model Generations 1) The monomer of polypyrrole known as pyrrole was imported from software library and shown. To make presentable the display style was chosen to be â€Å"Ball and Stick† by right clicking the model. 2) Then to make the polymer the â€Å"Build Polymer† was selected from â€Å"Build† tab and chosen Current Project from library menu. Chain Length was re-arranged to 5 monomers to fit on screen for simulation purposes. 3) Click â€Å"Window† tab from Title Bar and chose â€Å"Tile Vertically† as Display Style. Then Click on any of the two pictures and right click and select â€Å"Display Style†, navigate to Legends tab and uncheck Show axis indicator. Then go to background and change it to White to comply with report’s page background. Follow the same instructions for the other picture also. 4) Then right click on any of the two pictures and chose â€Å"Label†, change the font to 16 and change text colour to Black, then chose â€Å"Element Symbol† from Properties and press close. Repeat this step for the other picture as well. 5) Select 3D viewer from the buttons above to fit to screen for both pictures and then from â€Å"File† click Export, change the format to â€Å".bmp† and save to simulations folder. 2.2 Thermal, Physical and Mechanical Properties 1) Now from the generated model choose the Polymer and go to â€Å"Modules† tab and choose second last option known as â€Å"Synthia†. From the setup adjust the temperature to 200-800 and steps to 60. 2) Then go to properties, Select all the properties with â€Å"CTRL A† and uncheck them and then only select Density from Thermo-physical Filter and Brittle Fracture Stress from Mechanical Filter. Then Calculate. Export the results as MS Excel file and save to simulations folder to be used later. 3.0 Results and Discussions All the results and there conclusions are mentioned here on. The results of simulation include effects of temperature on Glass Transition Temperature, Brittle Fracture Stress and Density. 3.1 Model Generation The model for simulation was generated with the following monomer (Pyrrole) having this structure (Figure 1.0): Figure 1.0 Structure of Pyrrole The monomer is made up of an aromatic ring which is an amine due to its bonding with NH group. The basic formula is C4H4NH. There is a delocalised pair of electrons on Nitrogen. At position 2, 3, 4 and 5 each carbon atom is bonded to one hydrogen atom. Positions 2-3 and 4-5 have double bonds between the carbon atoms. Although pyrrole belongs to an amine group but it has relatively low basicity because of the lone pair of electrons of Nitrogen in the aromatic ring. The monomers synthesis to form the polymer, Polypyrrole: Figure 1.1 Structure of Polypyrrole The polymer is synthesised in two manners, electrically and chemically. In Figure 1.1, a chain of 5 repeat units is used. The preferred bond formation in the aromatic ring occurs at position 2 and 5. In support to the Wan Der Walls forces, there is also hydrogen bonding of side chains between Nitrogen and Hydrogen thus forming a Branched structure of the polymer. Since the structure consists of Benzene ring so it gives the polymer a very rigid form. 3.2 Thermal, Physical and Mechanical Properties 3.2.1 Study on thermal property (Glass transition temperature, Tg) According to Notes by Mr Lim SC (2012), â€Å"Glass Transition Temperature (Tg) is the specific temperature at which a non-crystalline material changes it state from being Glassy/Brittle to being Ductile or rubbery.† With the help of Simulation, the following Results table was devised for Pyrrole.

Textile Industry Trends in the Global Economy Essay -- Economics Techn

Textile Industry Trends in the Global Economy I. Executive Summary The objective of this paper is to examine how the development of a textile industry contributes to economic growth in the global economy. Because textile manufacturing is a labor-intensive industry, developing countries are able to utilize their labor surplus to enter the market and begin the process of building an industrial economy. Emerging economies then look outward to develop an export strategy based on their comparative advantage in labor costs. Textile production and consumption is an increasingly global affair as production continues to shift to developing countries. Developing countries have seen an explosion in the growth of their textile exports, and for many countries textiles are a significant portion of their total exports. In response to increasing competition from low-value imports from developing countries, industry leaders in developed countries have made significant capital investments in order to increase productivity and move into advanced market sectors. There are several trade agreements in place that impact world textile trade. The African Growth and Opportunities Act, Andean Trade Preference Act, and Trade Promotion Act are each designed to liberalize textile trade and provide equal market access to both developing and developed countries. Despite the potential economic and social benefits, the effectiveness of these trade policies is limited by special interest politics in the developed world. The presence of a political economy in developed countries can affect both the formation of and the adherence to international trade agreements; industry leaders can still appeal to the World Trade Organization or their Trade... ... as Kenya Plans More EPZs.† East African 22 April 2002. 10 October 2002 Tomkin, Robert. Trade Promotion Authority: CQ House Action Report. July 26, 2002. â€Å"Trade with Sub-Saharan Africa† Export America. December 2001. U.S. Congress, Office of Technology Assessment, The U.S. Textile and Apparel Industry: A Revolution in Progress–Special Report, OTA-TET-332 (Washington, DC: U.S. Government Printing Office, April 1987). Yang, Yongzheng. â€Å"China’s Textile and Clothing Exports: Changing International Comparative Advantage and its Policy Implications.† Asia Pacific Press, 1999. http://ncdsnet.anu.edu.au/ [link no longer working]

Transcendentalist Mccandless

Transcendentalist McCandless What is transcendentalism? How is Christopher J. McCandless a transcendentalist? Transcendentalism is a philosophy, and a way of life. It consists of being a non-conformist, becoming one with nature, and rejecting materialism. Throughout Jon Krakauer’s novel, Into The Wild, McCandless happens to achieve all of the above. â€Å"Whoso would be a man, must be a non-conformist† (Emerson). He defied society, lived in the wild, and never cared about â€Å"things†. He existed off the land in Alaska, the west coast, and even Mexico. McCandless did not want anything else in life but happiness; he found this in the wilderness.As Emerson states in Self-Reliance, â€Å"society everywhere is in conspiracy against the manhood of ever one of its members. † Conforming to society means to not be true to oneself. McCandless thought that conforming to society would make him another robot citizen. He believed in having his own opinion, being origi nal, and living how he wanted to. He proved this by â€Å"wandering across North America in search of raw, transcendent experience† (Krakauer authors note). This describes the adventure of his life, what he wanted, and what his plans were. Nobody knew Chris had planned on this.During his time working at McDonalds, McCandless also refused to wear socks. The assistant manager, George Dreeszen, even says that Chris â€Å"just plain couldn’t stand to wear socks† (40). McCandless did not care what people criticize him for, he did what he wanted to do, not what others told him was proper. In fact, as soon as he was done work he would immediately take his socks off. Another way McCandless proves to being a non-conformist is by living in the Slabs. Anybody could live in the Slabs, â€Å"the retired, the exiled, the destitute, the perpetually unemployed.Its constituents are men and women and children of all ages†¦the middle-class grind† (43). Any type and eve ry type of person lived in the Slabs. Chris felt accepted here, for nobody was judging your every move. By wearing no socks, living in the Slabs, and doing what he wanted made McCandless a non-conformist, a social outcast. Throughout the novel, it is evident that McCandless promotes becoming one with nature by talking about it with other employees when working at McDonald’s, writing about it in a letter to Ronald Franz, and writing about it in other letters as well.For example, in a letter McCandless wrote to Ronald Franz, he talks about becoming one with nature. He pressures how Franz should life his life. McCandless states, â€Å"you must lose your inclination for monotonous security and adopt a helter-skelter style of†¦ Don’t settle down and sit in one place. Move around, be nomadic, make each day a new horizon† (57). McCandless not only wants a life in the wild, he is also trying to spread the wilderness lifestyle to Franz. Likewise, while McCandless wa s employed at Bullhead’s McDonalds, he tends to talk about becoming one with nature.Other employees could tell that he loved nature by spending very little time with him. Lori Zarza, the second assistant manager of the McDonald’s, states that, â€Å"he was always going on about trees and nature and weird stuff like that† (40). McCandless was infatuated over the idea of living in the wild. Moreover, in another letter that McCandless wrote, he talks about how nature has transformed him. McCandless states, â€Å"The beauty of this country is becoming part of me† (91). He is absorbing the country; it is changing the way he looks at life. McCandless can only fixate on becoming one with nature while he is not in its presence.Christopher McCandless rejects materialism during the course of the novel and pursues the simple life by refusing a brand new car from his parents, rebuffing Jim Gallien’s watch, and giving his savings away, and burning his cash. McC andless first rejects materialism by burning all the cash he had left after giving away his savings. He did not wish to be able to use money as a way to help him. â€Å"He changed his name, gave the entire balance of a twenty-four-thousand-dollar savings account to charity, abandoned his car and most of his possessions, [and] burned all the cash in his wallet† (Author’s Note).Any materialistic person would consider him crazy for his bizarre actions. Then, he turns down a brand new car his parents offered to buy him. He believed his car to be in perfect condition. McCandless states, â€Å"I’ve told them a million times that I have the best car in the world†¦ yet they ignore what I say and think I’d actually accept a new car from them† (21). McCandless has visibly made his point that he does not want any â€Å"things†. McCandless then goes on to decline Jim Gallien’s offer to take his watch. He did not want to know the time nor whe re he was.Gallien states that wished not, â€Å"to know what time it is. I don’t want to know what day it is or where I am† (7). McCandless wants to be as free as he can, having a watch will give him too much unnecessary information. A typical materialist has reasons to believe McCandless as outlandish for his discarding of his money, and not wanting a free watch or car. McCandless did not worry about the â€Å"things† in life; he just wanted happiness. Krakauer proved McCandless to be a transcendentalist. McCandless could not care less about the standards that were bestowed upon his generation.He wanted to be himself, not a societal robot. McCandless did not enjoy wearing socks, he lived in the Slabs; a place where almost all non-conformist go. He left the Slabs to live in the wilderness; he worshipped the wilderness, which led to his demise. Of all the things that were offered to him, McCandless accepted none. â€Å"Rather than love, than money, than fame, gi ve me truth† (117). He just wanted the truth to his family. He wanted happiness, McCandless wanted to know everything would be safe and sound. McCandless is a transcendentalist, he only wished to be happy, free of all the â€Å"things†, and in the wild.

Word Class Definition and Examples

In English grammar, a word class is a set of words that display the same formal properties, especially their inflections and distribution. The term word class is similar to the more traditional term, part of speech. It is also variously called grammatical category, lexical category, and  syntactic category (although these terms are not wholly or universally synonymous). The two major families of word classes are lexical (or open or form) classes (nouns, verbs, adjectives, adverbs) and function (or closed or structure) classes (determiners, particles, prepositions, and others). Examples and Observations When linguists began to look closely at English grammatical structure in the 1940s and 1950s, they encountered so many problems of identification and definition that the term part of speech soon fell out of favor, word class being introduced instead. Word classes are equivalent to parts of speech, but defined according to strict linguistic criteria. (David Crystal, The Cambridge Encyclopedia of the English Language, 2nd ed. Cambridge University Press, 2003)There is no single correct way of analyzing words into word classes...Grammarians disagree about the boundaries between the word classes (see gradience), and it is not always clear whether to lump subcategories together or to split them. For example, in some grammars...pronouns are classed as nouns, whereas in other frameworks...they are treated as a separate word class. (Bas Aarts, Sylvia Chalker, Edmund Weiner,  The Oxford Dictionary of English Grammar, 2nd ed. Oxford University Press, 2014) Form Classes and Structure Classes [The] distinction between lexical and grammatical meaning determines the first division in our classification: form-class words and structure-class words. In general, the form classes provide the primary lexical content; the structure classes explain the grammatical or structural relationship. Think of the form-class words as the bricks of the language and the structure words as the mortar that holds them together. The form classes also known as content words or open classes include: NounsVerbsAdjectivesAdverbs The structure classes, also known as function words or closed classes, include: DeterminersPronounsAuxiliariesConjunctionsQualifiersInterrogativesPrepositionsExpletivesParticles Probably the most striking difference between the form classes and the structure classes is characterized by their numbers. Of the half million or more words in our language, the structure words—with some notable exceptions—can be counted in the hundreds. The form classes, however, are large, open classes; new nouns and verbs and adjectives and adverbs regularly enter the language as new technology and new ideas require them. (Martha Kolln and Robert Funk, Understanding English Grammar. Allyn and Bacon, 1998) One Word, Multiple Classes Items may belong to more than one class. In most instances, we can only assign a word to a word class when we encounter it in context. Looks is a verb in It looks good, but a noun in She has good looks; that is a conjunction in I know that they are abroad, but a pronoun in I know that and a determiner in I know that man; one is a generic pronoun in One must be careful not to offend them, but a numeral in Give me one good reason. (Sidney Greenbaum, Oxford English Grammar. Oxford University Press, 1996) Suffixes as Signals We recognize the class of a word by its use in context. Some words have suffixes (endings added to words to form new words) that help to signal the class they belong to. These suffixes are not necessarily sufficient in themselves to identify the class of a word. For example, -ly is a typical suffix for adverbs (slowly, proudly), but we also find this suffix in adjectives: cowardly, homely, manly. And we can sometimes convert words from one class to another even though they have suffixes that are typical of their original class: an engineer, to engineer; a negative response, a negative. (Sidney Greenbaum and Gerald Nelson, An Introduction to English Grammar, 3rd ed. Pearson, 2009) A Matter of Degree [N]ot all the members of a class will necessarily have all the identifying properties. Membership in a particular class is really a matter of degree. In this regard, grammar is not so different from the real world. There are prototypical sports like football and not so sporty sports like darts. There are exemplary mammals like dogs and freakish ones like the platypus. Similarly, there are good examples of verbs like watch and lousy examples like beware; exemplary nouns like chair that display all the features of a typical noun and some not so good ones like Kenny. (Kersti Bà ¶rjars and Kate Burridge, Introducing English Grammar, 2nd ed. Hodder, 2010)