Different Kinds of Engineering Material Assignment - 1

Different Kinds of Engineering Material - Assignment Example Brittle fracture basically is a fracture where there is a rapid run of cracks within the stressed material. In this case, the crack works much faster and it is difficult to understand the fracture before failure occurs. The scientific principle in the brittle fracture is that the crack moves close to the perpendicular where the stress is applied, because of this action, there remains a perpendicular fracture which leaves a flat surface at the broken area. Apart from having a flat fracture surface, brittle material more or less showcase a pattern on their fractured surface. Fatigue is the most common material failures found in the engineering field. Fatigue is a kind of failure mode where the material tends to fracture by means of progressive brittle cracking with regard to a repeated cycle of stress. Here, the stress implied on the material is of lesser intensity which means below the average strength. Creep is a failure mode which occurs on engineering materials at an elevated speed. Basically, it is seen on stainless steel when there is constant stress on the material with exposure to high temperatures. According to â€Å"The stress that produces a specified minimum creep rate of an alloy or a specified amount of creep deformation in a given time (for example, 1% of total 100,000 h) is referred to as the limiting creep strength or limiting stress†. The destructive test method is performed to understand the strength, hardness, and toughness of a material. The test utilized here is the stress test and for this purpose, the material chosen was the aluminum crank arm. The specimen was obtained and different loads and stresses were applied on the same. The destructive testing which is also known as mechanical testing displayed some results when stress was put on the iron with the help of a hammer.  

Who Owns History The Texas Textbook Controversy Essay - 1

Who Owns History The Texas Textbook Controversy - Essay Example The question on how history should be taught was brought to the limelight by the state of Texas. The Texas State Board of Education, in charge of the state’s curriculum, approved several controversial changes to be made to the textbooks in schools. The changes were included in the economic, social studies and history textbooks. These ‘improvements’ made by the education board emphasizes the Christianitys influence in the founding of America (Hutchins et. al. 652). The changes downplay the role of liberals and highlight the influence of conservative groups in American history. These changes, for the Texan board, seem minimal with no consequences on the American history, but the opposite is true. These small changes and tweaks in their curriculum seek to re-write the American history significantly for the students in Texas. Furthermore, the state of Texas is among the country’s biggest purchasers of History textbooks. This means that the changes in the Texan curriculum will slowly reflect in all schools throughout the country. They exclude the influence and existence of Thomas Jefferson, one of the country’s founding fathers. The Texan board excludes his influence on the Declaration of Independence and other vital legislation (Hutchins et. al. 653). Jefferson is not the only culprit of the Texan board; they further scrap off presidential runs of Ralph Nader and Ross Perot in their history books. There is a complete exclusion of the roles of Latinos and other races in America History. The changes implemented in the Texan History textbooks are endless, but it is heavily characterized by the conservative Christian influences. By changing and rewriting history of the state of Texas, the Texan board rewrote the world’s history. These changes made by the Texan board question the legitimacy of history and the appropriate way of teaching the subject. It is a universally accepted