Racism in to Kill a Mockingbird

Harper Lee uses racism in, To Kill a Mockingbird, to show readers the bad outcomes of racist thoughts and ideas. The sentence of life in prison to Tom Robinson, Atticus defending Tom Robinson, and Jem's thoughts on Black people's blood are all examples of Harper Lee's intentions. Racism is the hatred or intolerance of another race and is a theme that is ever present in Harper Lee's book, To Kill a Mockingbird. Tom Robinson was being sentenced to life in prison for supposedly raping Mayella Ewell even though there is proof that he did not.The jury voted him guilty as charged. â€Å"In our courts, when it's a white man's word against a black man's word the white man always wins. They're ugly, but those are the facts of life. † Atticus tells Jem. This is a terrible outcome of Racism. Tom Robinsons life is now gone because of white man in the jury being prejudice against a black man essay writer cheap. When Atticus decides to a Tom Robinson he gets sworn at by getting called a â⠂¬Å"nigger-lover† by many even his own nephew. â€Å"‘Francis, what the hell do you mean? / ‘Just what I said. Grandma says it's bad enough he lets you run wild, but now he turned out to be a nigger lover. ‘† Those who are racist are very arrogant and proud but those who are affected by it are affected greatly. Tom Robinson and Atticus are just two of many that are affected by Racism. Even Atticus, a white man, is affected by the patronizing on slaughter of racist remarks. Jem, slightly brainwashed by his town and community, has racist thoughts and ideas about Negroes.Jem tells scout outside of the courthouse â€Å"Once you have a drop of Negro blood, that makes you all black. † This example of racism shows how even children, at best, are showing signs of racism in a country where there should not be any. Harper Lee is showing the older community is doing to Maycomb's children. Basically they are brainwashing the kids without even knowing it. Th eir children just go by what their parents do and say. Thought Jem said a racist remark, later on in To Kill a Mockingbird he does not show much racists thoughts.In fact, Jem learns about racism during and after Tom Robinson's trial. Harper Lee uses racism to show readers the bad outcomes of racist thoughts and ideas. The sentence of life in prison to Tom Robinson, Atticus defending Tom Robinson, and Jem's thoughts on Black people's blood are all examples of Harper Lee's intentions. Though Racism is still in this world today Harper Lee shows what racism does and how it works; thus proving the bad outcomes and results of racism.

Grenz Review

TY 170 February 23, 2009 Grenz Review As time passes, different themes are presented throughout society. These themes tend to make attempts at disproving its predecessor. In Stanley J. Grenz’ book, A Primer on Postmodernism, he discusses the two most recent ideas supported by the public; modernism and postmodernism. The opposition is apparent between the eras of modernity and postmodernity. As described by Grenz, modernity focuses on the individual, using reasoning as a source of the truth. This belief causes truth to be relative.Postmodernity’s focal point is the group, rather than the individual. Truth, in the postmodern view, is created by intuition and feeling, causing it to be constructed. Grenz also discusses both the problems postmodernity pose on Christianity and the similarities between postmodernism and Christianity. Grenz’ portrait of postmodernism is accurate for what society is facing today. In order to understand the differences between modernism an d postmodernism as Grenz has defined them, first understanding of how each was created is needed.Modernity is based around meta-narratives; stories that connect everyone together. The most profound meta-narrative of modernity is the universal truth of science. One of the most important constructs of modernity is individualism, upon which all modern thinkers based their work. â€Å"Most historians suggest that the modern era was born when the Enlightenment brought new hope to war-ravaged Europe† (57). The Enlightenment had four principles; â€Å"Reason, nature, autonomy, and harmony† (68). These principles created the foundation for modern thinkers.Many modern thinkers throughout the era, regardless of their discipline, â€Å"Turned to the reasoning subject rather than divine revelation as the starting point for knowledge and reflection† (65). Through these foundations set for modernity, the modern philosophers turned to science in support for their hypotheses. à ¢â‚¬Å"Thinkers such as Descartes, Newton, and Kant provided the intellectual foundation for the modern era† (80). Rene Descartes was one of the first modern thinkers of his time, â€Å"often being referred to as the father of modern philosophy† (63). When Descartes irst set out on his journey for knowledge, he set out with doubt, in search of absolute truth that doubt could not deny (64). Like many other thinkers of that period, he â€Å"Attempted to introduce the rigor of mathematical demonstration into all fields of knowledge,† because he believed that the truths of mathematics were more concrete than knowledge based on observation (64). Descartes eventually reached the destination of his searching; the one thing that could not be doubted was one’s own existence. His new way of thinking led to a different outlook of the human person.His work defined â€Å"The human being as thinking substance and the human person as an autonomous rational subject† (64). This new definition supported Augustine’s philosophy; â€Å"Cogito ergo sum – ‘I think, therefore I am,† (64). Although Descartes’ work did not discover subjectivity, â€Å"the chief importance of his contribution lies in his emphasis on personal experience and personal knowledge, on knowledge arising from the individual’s unique point of view† (64). His role in the Enlightenment paved the path for his modern-thinking successors.Following Descartes’ work, Newton began making his own imprint on the world, emphasizing the importance of science. His work focused on trying to explain the workings of his universe that he saw as a â€Å"Grand, orderly machine,† (67). Newton’s idea of the world as a machine provided the framework for modernity. Newton believed that by viewing the world as a machine, he would be able to know its movements because it would follow a set of distinct laws (67). His design led modern thi nkers to have a mechanistic understanding of the world, as opposed to a natural view (50).Although Newton looked at the scientific explanations of the world, his intent was to explain the existence of God. Similar to Descartes, Newton used the power of reason to enhance the meaning of theology. â€Å"The modern world turned out to be Newton’s mechanistic universe populated by Descartes’ autonomous, rational substance† (67). Through Newton’s work, other philosophers had the foundation needed to make their own impressions on the world of modernity. Eventually, philosophers began questioning the Enlightenment and modernity as a whole.Through Immanuel Kant’s work, he strengthened the ties between society and modernity, which associated himself with the beginning of the Enlightenment. Kant’s most important contribution to modernity was his publication of Critique of Pure Reason (57). His critique strengthened the support of modernity and terminat ed all questioning of it. Kant sought to create a more concrete platform for metaphysics through his writing (76). He hypothesized that the mind is systematical in organizing sensations from the external world. â€Å"According to Kant, the human person is not only a creature capable of sense experience bus also a moral being† (77).Kant believed that by living morally, one lives the way he wishes all people would live. He argued that the moral aspect of human existence is essentially rational (78). This view of existence created the realm of practical reason, which encouraged other modern philosophers to concentrate on the individual self. This attentiveness came from Kant introducing the idea that the self is â€Å"not just the focus of philosophical attention but the entire subject matter of philosophy† (79). Through this notion, Kant directed his attention to the individual imposing reality.Kant’s work provided future philosophers with the concepts needed to u nderstand and eventually deconstruct modernity. Johann Gottlieb Fichte operated off of Kant’s discoveries. He accepted Kant’s work but also â€Å"Was enabled to explode it from the inside† (87). Fichte did not want to eliminate Kant’s ideas, but instead wanted â€Å"To expose the Kantian ‘fiction’ of an objective world existing in its own right beyond the self,† (87). Through his work, Kant emphasized the idea â€Å"that the self creates and determines the objects that constitute its own external world† (87). Hence, the realm that Kant claims to know through ‘pure’ reason, Fichte claims to produce through the exercise of ‘practical’ reason† (87). His work has created a freedom that â€Å"is important because it holds the potential of liberating us from a single way of understanding the world,† (88). Fichte managed to dissolve Kant’s idea of an absolute reality through â€Å"eliminat ing the noumenal realm† (88). Although he worked against Kant in many ways, Fichte managed to uphold Kant’s concept of the absolute self (87).Fichte, along with other thinkers’, beliefs led to what is now considered to be the postmodernism era by questioning the context of modernity and its constructors. Postmodernism is the mere rejection of the ideas that modernism and the Enlightenment support. The main theory that postmodernism rejects is the construct of individualism. In its denunciation of modernism, it also rejects the modern theme of meta-narratives, except for its own. The postmodern world does not believe that all knowledge is good, nor that knowledge is objective. They view life on earth as fragile and believe that the continued existence of humankind is dependent on a new attitude of cooperation rather than conquest† (7). Postmodern beliefs have a more pessimistic view on the world, as opposed to the modern idea. Postmoderns believe that the wo rld is â€Å"historical, relational, and personal† (7). The main postmodern view is that everything is different from everything (7). â€Å"Many voices have joined the postmodern chorus. But of these, three loom as both central and paradigmatic – Michel Foucault, Jacques Derrida, and Richard Rorty.They constitute a trio of postmodern prophets† (123). Michel Foucault was persistent in the rejection of the modern worldview. He argued that â€Å"reason and rational discourse are problematic.. , because they require that we squeeze the variety of reality into the artificial homogeneity that accommodates our concepts† (127). His intentions were not to present the ideas of a better society, but to understand order. This new society that Foucault presented was called â€Å"’heterotopia,’† as opposed to the modern view of â€Å"utopia† (20).Foucault focused on the connection between knowledge and power in regards to social systems, sta ting that â€Å"every interpretation of reality is an assertion of power† (6). Foucault believed that this power was â€Å"the power of violence† (59). He used genealogy to gain a better understanding of how we arrived to the beliefs supported by society (135). â€Å"According to Foucault, the practice of genealogy informs us that history is not controlled by destiny or some regulative mechanism but is the product of haphazard conflicts† (136).He reveals himself to be the model postmodern by making the assertion that â€Å"no natural order lies behind what we invent through our use of language† (137). Foucault provided a new outlet for the newly formed notion to be interpreted by future philosophers. Subsequent to Michel Foucault, Jacques Derrida reinterpreted some ideas of postmodernism. Unlike Foucault, Derrida had different views on what was in correct about modernism. He focused on defying logocentrism: â€Å"The philosophical method that looks to th e word as the carrier of meaning† (141).He began, in a sense, where Kant left of by questioning â€Å"what foundation can we offer for our use of reason† (140). Derrida was critical of Western philosophers in saying that they view writing as a demonstration of speech. He spent his lifetime of work trying to deconstruct the idea that written language represents reality. Unlike Foucault, Derrida did not try to create new ideas for postmodernism on the basis of old ideas; he rather deconstructed or disproved the foundations of modernism. Derrida wanted to demolish the modern construct that â€Å"views philosophy as pure, disinterested inquiry† (148).Along with that, he also wanted to renounce the popular idea that there is a clear link between language and the external world, (148). â€Å"Derrida’s primary goal is to divest us of logocentrism by showing the impossibility of drawing a clear line between reality and our linguistic representations† (148). Overall, Derrida’s target for deconstruction was Western philosophy as a whole. The ideas represented by the philosophy were viewed as hopeless by Derrida. The notions that Derrida brought to the table allowed thinkers to move past the modern ways and seek refuge in postmodernism.After Derrida, came a philosopher with a new way of thinking, Richard Rorty. Unlike his predecessors, Rorty expressed his belief in a clear style. Rorty is considered to be â€Å"the central figure behind the renewed interest in the American pragmatist tradition† (151). His pragmatist outlook abandoned an Enlightenment idea; â€Å"The mind is the ‘mirror of nature’† (151). In pragmatism, the view of truth is that it is a result of human convention, thus it is constructed. Similar to Derrida, Rorty believes that language does not have the capability to represent the world accurately.He views language as a device used to satisfy one’s wants and needs. Working against modernism, he also states that â€Å"we give up the idea that the goal of science is to produce models that correspond perfectly with reality† (154). Rorty believes that science is just one way to view the world, but there are many other ways to perceive it. Through the work of Foucault, Derrida, and Rorty, a new way of thinking was born which opened the world up for questioning. Postmodernism and Christianity have a working relationship. That is, Christians support and also disagree with some postmodern concepts.When postmodernism was first presented as an idea, Christians did not know how to approach it. A concern that Christians have with the postmodern view is the rejection of meta-narratives. The concept of stories uniting a group as one is the foundation for Christianity. As Grenz states, â€Å"We simply do not share the despair over the loss of universality that leads to the radical skepticism of the emerging era† (165). In addition to the rejection of meta-narr atives, postmodernism focuses on the inability to discover an all-encompassing truth. Here lies the major dilemma Christianity has with postmodernity.Christians believe that God includes the truth about everything, but postmodern thinkers do not believe that an â€Å"all-encompassing truth† is possible to reach (163). The postmodern rejection of individualism worries Christians because they â€Å"must always keep in view the biblical themes of God’s concern for each person, the responsibility of every human before God, and the individual orientation that lies within the salvation message† (168). On the other hand, Christians support the rejection of the Enlightenment idea that â€Å"the rational, scientific method is the sole measure of truth† (166).Also, the postmodern denial that all knowledge is good and objective strengthens the ties between Christianity and postmodernism (168). Christians also support the postmodern finding that no person can be sepa rate from creation. As years pass, Christians are more accepting of postmodern concepts and are more rejecting of the modern ideas they once supported. Grenz’ view of the postmodern world is acceptable for what society faces today. The postmodern views have been mirrored throughout the public. Even in school, teachers focus more on group projects and group activities rather than the individuals.Children judge each other on the amount of time they spend with others, as opposed to the ability to spend time alone. Now, it is a must for children to always be with their friends. It is also represented in the working world. Bosses would prefer group presentations rather than individual. Most people do not like to be alone or even to be singled-out. Also, as the economy is closer to being in a recession, the postmodern idea that the world is not getting better every day is strengthened. People no longer believe â€Å"that humanity will be able to solve the world’s greatest r oblems or even that their economic situation will surpass that of their parents,† (7). Every day it seems as though the world is not capable to overcome what it has started, such as wars. It seems as though the world is no longer a â€Å"happy† place at most times. The postmodern pessimistic view is presented daily. It is awkward for others when people are optimistic about their life. Overall, people seem accepting to the postmodern views. Over the years, the world has seen different phases sweep through, and each one is eventually accepted. The most current themes are modernity and postmodernity.The modern views were set forth by Rene Descartes, Isaac Newton, and Immanuel Kant. Modernism is the idea of focusing on the individual in means of scientific explanations. Also, modern thinkers believe that all knowledge is inherently good. Johann Gottlieb Fichte is partially responsible for the beginning of questioning modernity. Once Fichte opened the doors, Michel Foucault, Jacques Derrida, and Richard Rorty put an end to the modern way of thinking. What their idea created was postmodernity. The postmodern thinker steps away from the individual, focusing more on group relations.Also, postmodernism denies that all knowledge is essentially good. This new way of thinking has made Christians question how to respond. Christians agree, but also disagree with some of the postmodern views. As a whole, the world has come to terms with postmodernism by accepting it. What is going to happen when philosophers begin to question postmodernity? How will the world be viewed once people stop accepting postmodernism? Works Cited Grenz, Stanley J. A Primer on Postmodernism. Grand Rapids: William B. Eerdmans Publishing Company, 1996.

Analytical Paper

Presenting the public with two â€Å"equal† sides and making the scientific community seem divided. The best way that constrains Interfered with a scientific consensus was to generate doubt within the American public by creating a delve between scientists. For example, the harmfulness of acid rain was questioned when Fred Singer 1 contradicted the factual evidence of his committee by claiming in an official government report that the causes of acid rain were not certain and that a reduction in industrial emissions would not necessarily help solve the problem.Both of these statements were in direct contradiction with the international scientific community, which made the consensus seem wavering and the official White House-appointed panel seem divided. Fred Singer reemerges on the issue of ozone depletion by blasting the science community when claiming that the whole issue was an under- researched overreaction (1 26); he claimed that ozone depletion was due to natural stratosph eric cooling (127).Several years later, Bill Emergencies created doubt over climate change when he lead a report asserting that rolling CA was a problem that loud be solved with technology and the government only needed to fund more research (183). Merchants of Doubt provides countless examples of contraction scientists chopping down the certainty of scientific findings. Constrains like Singer and Energetic are able to discredit the work of thousands of scientists because they are praised leading scientists who have served in distinguished federal science corporations.They have developed ties to the government through federal agencies, think tanks, and direct contact with congressman, senators, and presidents (7). Secondly, the people who are being arrogated by scientists are industries with lots of money, which have the resources to hire and provide funding to influential people who will defend their products. With strong reputations and money, contraction scientists are perceived as â€Å"experts† with â€Å"Informed opinions† and thus are granted a false sense of credibility and Influence.Tactic #2: Tagging scientist as â€Å"bad† and calling their findings â€Å"junk. † Fred Sister, an influential defender of the tobacco industry, invented a tactic of contraction scientists that targeted the EPA as a Junk organization whose science â€Å"is manipulated to fulfill a political agenda† (144) and â€Å"imposes enormous economic costs on all aspects of society† (142). Sites and Singer blasted their views of the EPA as â€Å"bad scientists† all over public media venues such as the Wall Street Journal and the Washington Post.Singer attacked the EPA for not considering that adverse health effects from second hand smoke could be due to outside factors when doing an epidemiological study; he claimed the EPA rigged their results and ignored other possibilities In order to dupe the public (144). I believe the â€Å"bad science† argument Is accepted by the public because science Is nearly misunderstood for a variety of reasons. Firstly, research results can be complicated and generally confusing to a nonscientific, therefore the public must credible counterargument and splitting the scientific consensus (Task #1).Most people have no scientific baseline from which to make informed opinions so they gather information from â€Å"experts† from both sides of a scientific story. Secondly, science in general is an objective project, scientists stress that their results are always falsifiable and that continued research is necessary to strengthen a scientific finding. For example, Roger Reveille started a talk to the AAAS about climate change by saying, â€Å"There is a good but by no means certain chance that the world's average climate will become significantly warmer during the next century' (191).Constrains used this ambiguous statement as a way to show that scientists are unsure of thei r work, when in fact there is no â€Å"certain chance† in any scientific trend. In order to remain trustworthy, scientists must always instill a sense of impartiality that is misconstrued as uncertainty. Tactic #3: Making the public believe that environmentalism is a threat to the American value system. One goal of scientific findings on acid rain or the ozone hole is to invoke political action that will ensure safety to humans and the environment.Contraction scientists claim that this goal is UN-American and that the corrupt political agenda of environmentalism is a threat to human rights. For example, a pro-smoking organization, FORESTS, claimed that if smoking was banned, â€Å"there is essentially no limit to how much government can ultimately control our lives† (164). As Singer and Sites would put it, it was individual liberty at stake. â€Å"Today smoking, tomorrow†¦ Who knew? (145). Science was also attacked for being uneconomic. Dixie Lee Ray in the 1992 Progress Foundation Economic Conference claimed â€Å"sustainability was replacing [economic] progress† (252).Constrains aimed to convince Americans that by protecting industry they were protecting their â€Å"liberty that depended on [economic] progress† (252). This tactic was made possible because constrains tapped into the American fear of the communist Soviet Union by claiming that environmentalism was a socialist endeavor. They pegged environmentalists as â€Å"Watermelons': green on the outside, red on the inside† (248). When the Cold War ended, constrains funneled socialist fear into an anti-climate change movement, which revolved around the idea that climate change was against American's liberty and prosperity.The attackers believed they were â€Å"working to ‘secure the blessings of liberty as if science was being used against those blessings?in ways that challenged the freedom of free enterprise† (238). Constrains put science under the fir e by claiming that its agenda was to deny the rights of citizens, much like the Soviets did to their citizens in the Cold War. Conclusion: The players mentioned?singer, Suite, Energetic, Lee Ray, and FOREST ?among others have created organized patterns of doubt that misconstrue the validity of research and science.Using money and influence, they have dismantled any form of consensus within the scientific community and have used popular media outlets to echo their claims. 9 They understand the American emphasis on economic have attacked scientists as being politically incentive socialists that threaten citizen's rights to freedom and prosperity. They have used these strategies to stunt political action in issues like acid rain and climate change and have caused the American public to lose faith in the credibility of science.

Multiple regression Term Paper Example | Topics and Well Written Essays - 1500 words

Multiple regression - Term Paper Example Multiple regression is an effective technique to identify a relationship between one dependent variable and multiple independent variables. It is hypothesized the property crime rates per thousand inhabitants is dependent on multiple factors such as per capita income, school dropout percentage, population density, percentage of people living in urban area and so on. In order to establish a certain relationship between the variables, multiple regression was used. While crimes is the dependent variable, other variables such as state, per capita income, dropouts, average precipitation, public aid recipients, population density, unemployment, percentage of people living in urban areas were considered as independent variable. Minitab was used to perform multiple regression analysis. It was found that only two variables had a significant relationship with the variable crime rates: dropouts and urban. It was found that as percentage of dropouts increased, the crime rate per thousand inhabit ants also increased. It is also evident from the data set that urban areas are having higher crime rates as compared to rural areas. Other variables included in the study did not have much impact on the dependent variable. The first column of the table below shows the regression coefficient of all the independent variables. The second column contains the standard error of the regression coefficient. The standard error of all the variables is the distance of the standard value from its true value. As can be seen from the table, the standard error of the constant term (intercept) is 1226 while it is 8.238 for the variable state. The third column is the calculated t-value for the data. This can be used to test that the corresponding population coefficient is 0. The probability that the population value for the corresponding variable is 0 is given in the last column. A row with small p-values and high t-values suggests that the variable is significant and contributes to the model.

Love Juvenile Justice Essay Example | Topics and Well Written Essays - 500 words

Love Juvenile Justice - Essay Example A juvenile who believes that â€Å"the system† has treated him or her unfairly may be less defensive if tried by an objective jury (Elrod and Ryder, 2011, pg. 127). This is to say, a perception of fair treatment may go a long way towards fostering acceptance of responsibility on the part of the juvenile. Thirdly, unlike in adult courts, the jurors in the juvenile systems are not peers of those on trials. In some instances, the juvenile may benefit from this fact, because the adults on the jury may remember their own youthful mistakes and indiscretions and feel sympathy (Elrod and Ryder, 2011, pg. 127). If they are parents, jurors also may realize that, under other circumstances, one of their children could be at the defence table. This in as much as may lead to the inclusion of emotions into the final judgement, it eats into the very consciousness of humanity which a jury is supposed to represent. Finally, Rosenberg (2008) noted that judges generally give a guilty verdict about 25 per cent more often than juries do. This discrepancy is something requiring a level of concern. The American bar association agrees with this finding and concludes that this could as a result of bias from the part of the judges. However, in as much as a trial by the jury is beneficial to the parties involved in any case, but especially the defendant, it also does have some limitations. Jury trials in juvenile proceedings may result to a backlog of cases and hamper the functioning of the juvenile court. Experience has shown that such trials seriously impede the juvenile justice process (Elrod and Ryder, 2011, pg. 126). Another central issue concerning jury trials for juveniles is the fact that these youth are not tried by a jury of their peers, but a jury of adults. A jury of one’s peers is based on two premises: that the jury be made up of members from the defendants’ community and that the defendant is entitled to an impartial jury (Roesch, Corrado and Dempster, 2001, pg. 53).

Dixons Retail Group e-commerce Assignment Example | Topics and Well Written Essays - 4250 words

Dixons Retail Group e-commerce - Assignment Example III. Market Profitability This is largely determined by the five forces identified by Porter (2008) as: power of buyers, power of suppliers, threat of new entrants, threat of substitutes and competitor rivalry. These are looked at in detail in the micro-environment section below. However, market profitability is low here because of intense competitor rivalry, strong buyers, high threat of substitutes and moderate threat of entry. IV. Industry Cost Structure According to Goldmanis et al. (2009) the introduction of e-commerce into an industry results in the shrinking and sometimes exit of high-cost firms and a shift in market share to low-cost firms, and with some additional assumptions about the firm type and consumer search cost distributions, a drop in the number of producers as well. Of the ten cost drivers related to value chain activities identified by (Porter, 1998) Primark derives its cost advantage largely from four: its vertical integration, economies of scale from the Gr oup, capacity utilisation and learning. V. Distribution Channel Dixons.co.uk leverages the centralised supply chain and distribution network of the Group’s physical stores. At Newark the company operates one of Europe’s largest distribution centres. Another Regional Distribution Centre (RDC) is located at Bristol to supply goods to all South/South west UK branches of Dixons Retail Group (Dixons Retail, 2011). Using the Group’s warehouse makes dixons.co.uk cost to serve relatively low (Chiles & Dau, 2005). VI. Market Trends Online retail industry is still largely in a state of flux due a range of factors. Firstly, the technology platform on which online retailing is based is still undergoing rapid change such as 3D virtual... According to the research findings as an e-commerce website, dixons.co.uk inherently faces three types of risks: security of customer data, consistency in order-fulfilment and accuracy in inventory management. Security risk arises because the company will have to store various forms of customer data such as contacts, purchasing habits and credit card records. The company will therefore have to invest in staff security awareness training and security technologies. With regards to order fulfilment, dixons.co.uk must ensure that it has the right processes in place that guarantees the customer receives what she ordered for in the right state, at the right location and at the right time. An effective and efficient order fulfilment process will save the company time and resources spent in handling returns and complaints. Finally, inventory management is important because it supports distribution and order fulfilment. However, the risk to be highlighted here is the synchronisation between t he items advertised on the website and the actual items available in the company’s warehouses. Consumer confidence can easily be lost in instances where customers order for a product that is no longer available at the company’s warehouse yet it is displayed on the website.A critical look at the above risks informs us that security of customer data, consistency in order-fulfilment and accuracy in inventory management are market qualifying factors in e-commerce. Hill’s methodology on marketing strategy define qualifying factors as those factors that a business must fulfil in order to be considered for business by customers.

Gangs in prisons Essay Example | Topics and Well Written Essays - 3500 words

Gangs in prisons - Essay Example The reasons of joining these gangs while in prisons are equally diversified and include the search for protection and in order to command control over all others. This study therefore intends to analyze the trends in prison gangs holistically within US, the reasons of their formation as well as the possible means of destroying them. The United States have increasingly been recording higher rates of gangs organized within the prisons over the last years (Sheldon, 2004). Both the increase in the number of gangs and gang members along with the increase in criminal activity by these individuals has lead to harsher responses by the criminal justice system including an increase in the incarceration of many gang members. For example, a study conducted in 1999 by prison administrators indicated that 24 percent of male prisoners and seven percent of female prisoners belong to a prison gang (Shelden, 2004). This was an approximately 167-percent increase in the number of prison gang members reported in 1991 whereby only nine percent of male and seven percent of female inmates reported belonging to a gang. In another study conducted in 1999 approximately 47,220 male were gang members in 1999 compared to a similar study in 1993 whereby 43,765 men were identified to be gang members in American prisons (a 7.9 percent increase ) (Shelden, Tracy & Brown, 2001). However, some states that have been identified with higher number of gangs in their prison population, for example Illinois, reported that as many as 34.3 percent of inmates belonged to a prison gang (Fleisher & Decker, 2001) which was the highest percent of prison gang-affiliated inmates in the nation. Despite the number of identified gang members in prisons, research on both the existence and the handling of gangs behind institutional walls is relatively nonexistent (Scott, 2001; Skarbek, 2012). Gangs exist in all prisons throughout United States (Fleisher & Decker, 2001).

Successfully Manage a Radical Change Within a Complex Organisation Essay

Successfully Manage a Radical Change Within a Complex Organisation - Essay Example pany implement re-engineering, reorganisation and cultural transformation, then the entire operational activities face radical changes in three levels. Firstly, changes occur among the personnel who employed within that particular organisation. These changes take place in terms of their attitude, skills, capabilities, attributes and behaviour regarding work place. Top level management should always aware about such behavioural changes which can impact upon the organisational working procedures. Secondly, changes can also take place in organisational structure and system which in turn might transform the existing working culture; procedures reward system and other activities. Thirdly, direct changes can also occur within the organisational culture which might effect upon employees relationship, can develop conflict and can impact on decision making procedures (Government of Jamaica, 2010). In this similar context, changes are completely depends upon business situation and always takes place in order to deal dynamic competitive circumstances. Some of the common changes happen in order to deal with new competitors and new technological innovation. All these changes take place in order to enhance operational efficiency and to obtain long term profitability (Dawson, 2010). By considering the present business scenario, change management is quite significant in every aspect of operational activities. Successful change ensures enhanced organisational ability to perform effectively within the new business environment. The fundamental source of change management is to enhance the capacity of employee to adopt changing working environment. There are some common factors which need to be considered for making a change successful. The first factor is appropriate planning which is... This paper stresses that the transition of an organisation gradually initiates. In this stage, managers try to build a readiness in order to tackle the change. In the awakening stage, the organisation assesses the problems and evaluates the possibilities of change. This can be done with the help of the information gathered from unconscious stage. In reordering stage, an organisation analyse the existing working situation comparatively with the changing scenario. This stage affects largely to the organisational stability and performance equilibrium of an individual personnel. The core idea which has been emerged from the overall discussion is that the major challenges which are coming from radical changes for the organisation is to uphold high productivity while facing transformative changes. The change is considered as an impact which might hamper the overall organisational work structure. Subsequently, on the other hand these changes may lead an organisation towards the high productivity. There are various types of models and principles by which an organisation can successfully adopt the changes into their working environment. It has been observed that the process of changes and transformation is significantly considered as an end and re-birth process where an organisation either shut down its operational activities or attain sustainable competitive advantage. Either cases, an organisation needs to experience and tackle necessary transformational changes in order to survive and grow. Successful change of an organisation effectively depends on personnel capability to incorporate changes in structure and work comfortably within new environment.

The analysis of teaching service Essay Example | Topics and Well Written Essays - 1750 words

The analysis of teaching service - Essay Example but it actually begins with requirement gathering, analysis, design, coding, testing and acceptance (basically what we have also in Agile methodology as well today). I was more involved in requirement gathering and later on testing part of the process. Therefore I can say I was also involved with such project. Before I use one of the projects as an example and describe about the Work System that was used and the elements of it, I wanted to share some of experiences I’ve had with Systems Analysis and Design. First of all I should I figured out that no matter how much a system is a large or small, the theory will always work if we pay attention to them. The standards would work if you know yours system at first and also if you know what the theory is talking about; although all of these need experience as well. Having said that I believe Systems Analysis and Design is one of the most important aspects of any development project. The better the analysis the easier the development and market new products as well as identify and enter new markets with existing and new products. There are a number of considerations I have related to system analysis and design. From an overarching perspective I recognize that the systems process occurs in nearly all environments. In this way I recognize that even psychology and family relationships have been considered in terms of systems elements. Bronfenbrenner (1979, p. 34) established Ecological Systems theory as a pervading mode of examining human relationships in the home and work environment. In these regards I recognize that not only the structure of work environments, but also the individuals interacting within these environments fall within the domain of systems elements. Another major recognition I have had related to system analysis and design is the relation of systematic inputs and their workplace functionality. Indeed, Alter (2006, p. 1) indicated that one of the primary challenges of system analysis and design i s ineffective design of inputs within the system. Dick & Carey (2009) indicated that the single most important factor of whether a systematic training input will be incorporated into the workplace environment is the context of that workplace. Many times in my past experience I have received training in an element that was later not directly relevant or supported in the workplace environment. Upon entering the workplace environment this systematic component was then disregarded because of ineffective structures. Ultimately, then I recognize that one of the most essential elements of systems and systematic design is ensuring that each of the components operate together in a functional and mechanistic way. Part III. For a nonprofit project I was involved in our specific work system was a high school teacher working in public education. Customers While there are not customers in the traditional sense, there are similar components. In this way there are students achieving and receiving t he learning. There are parents interested in their children’s education. There are administrators and state education board members interested in ensuring the education provided reflects well on their professional competency. Finally, there are business organizations concerned with ensuring that there is an educated workforce to choose from. Products and Services The products and service are course specific. In terms of a mathematics classroom it is important that students learn algebraic functions, geometry, and potentially calculus. Additionally, they gain critical thinking and problem solving abilities. In this way the products and services are the education that is provided for the students. This

Importance of Qualifications from an Aviation Manager’s Perspective Essay Example for Free

Importance of Qualifications from an Aviation Manager’s Perspective Essay Aviation is described as aircraft operation with the objective of providing air transportation. Air transportation can further be defined as all the civil flying which is performed by air carriers which are certificated and also the general aviation. The industry of air transport can be credited for its vital role it plays in the today’s global world. Management of the aviation industry is complex and thus it requires one to be competent so as to be able to deal with the challenges that face this industry in our modern world. In addition, the organizational and industrial overview of the air line business is also a complex task and can not be managed by a person who does not have qualifications in aviation management. One needs to have qualification in aviation management so as to make the organization to excel in the job market as well as to manage the other employees so as to improve performance of the organization (Yilmaz, 2008). To be able to manage the organization effectively, one need to understand on the quality of services that the company should produce so as to attract more customers and also he should have leadership traits which can enable him or her to control the behavior of the employees toward achievement of the organization. He should also be able to control conflicts that may be arising in the organization to make sure that workers are satisfied and thus they are working in a conducive environ Aviation industry need a management personnel who is competent so that he or she can be able evaluate the quantitative methods and applications in the organization. The personnel should be able to use the scientific management theories so as to support the situations of decision making by giving sound decisions which can help the organization to grow and even run profitably (Yilmaz, 2008). He or she should be able to use and apply various concepts in the organization such as the techniques of linear programming, the simulation methods, and the models of inventory control as well as the decision theory to ensure the organization is running efficiently. Furthermore, there is need for management personnel in the field of aviation to have knowledge about managerial accounting since it is a necessity in management. This will enable him or her to identify, accumulate, report and interpret the information about cost so as to make decision and control the general operation context (Yilmaz, 2008). It will also enable him to utilize and evaluate information supplied to him or her from accounting department. Having knowledge on managerial accounting can enable the management personnel to be able to have accounting tool which can enable him or her in determining on the performance of the organization. Aviation management personnel should be also qualified in the non profit and governmental accounting to enable him or her to be able to investigate the environment for decision making from a perspective of non-profit entity or public sector. This will enable the personnel to be able to analyze the consequences and also the regulation impact and the established pronouncements by governmental Accounting standards board, which is the comptroller of US and also the office of the general accounting for the federal. Aviation management personnel should also have knowledge on the financial management so that he can be able to have financial analysis, have measurement on the capital costs, capital management, capital budgeting, valuation and also in determining the analysis of the capital structures. A manager in the aviation industry should be competent and should be aware on the impact of the government as well as the current issues concerning aviation industry. He should be aware of this issue not particularly in the country but at a perspective of the world or globe. Aviation management personnel should be able to identify the market segment, to identify the trends that the organization must follow to achieve performance of the organization as well as identifying the developments that need to be introduced in the organization depending on the change in technological know how (Yilmaz, 2008). He should also be aware of the international standards required in the air transport industry so as to be competitive the market. Also being qualified will enable one to understand on the regulations and rules that govern air transport industry and make decisions on how to manage the operation of the organization according to such rules. The personnel should be able to forecast on the future trends and challenges using the present and the past trends of the industry so as to make the organization to be competitive in the market. There is also need of management aviation personnel to be competent so as to be able to identify the output and demand determinants in the organization as well as the labor relations. All in all, it is important for one to be qualified in aviation so as to be competent in the field of management in aviation industry. This is because one will be able to control all activities necessary in such industry so as to make it run efficiently and effectively for the growth or profitability of the organization.

A Review of Literature of Erosion of Soils

A Review of Literature of Erosion of Soils Introduction Numerous work and research have been undertaken on erosion of soils for many decades. The following literature review is focusing on the relevant topics in terms of soil erosion process as well as the parameters and factors of soil erosion .Moreover, the literature reviews is primarily focusing on the management and control the soil erosion. 1 Soil Erosion by Water To perform this study, it was necessary to understand how soil erosion occurs. Usually it occurs at a low level but can become a problem when the ecological balance disturbed by humans activities or severe weather .The risk of erosion by water when soils with a high sand or silt content that exposed to heavy rainfall. (Defray 2005). It is crucial that considering rainfall and runoff factors when assessing a water erosion problem (BC.S.Baldwin 2003) .Although the soil erosion caused by long-lasting or less-intense rainfall is not as spectacular .But soil movement by rainfall is most noticeable during the short-time, high-intensity thunderstorms and the amount of soil loss can be considerably, especially when compounded over time. While the excess water on a slope that cannot be absorbed into the soil or trapped on the surface, the runoff will occur. The amount of runoff can be increased if infiltration is reduced due to soil compaction. (BC.S.Baldwin 2003) Two stages process involved in the soil erosion, which depend on water detaching and transporting soil. Rainsplash is a key determinant of detachment of soil particles in the first stage of erosion. However, if a growing crop covers the soil surface, the erosive power of rain will dramatically reduced. Once it detached, surface water run off plays a key role in the process of soil particles being transported. Surface run-off can be easily happening during the heavy storms or prolonged rainfall. (BC.S.Baldwin 2003) Tess Wynn investigated the streambank retreat. Normally it is called streambank erosion, the occurrences involved the combination of three processes, subaerial process, fluvial entrainment and mass wasting. Specifically. The term â€Å"subaerial process† is used to describe the climate- related phenomena that reduce the strength of soil .It mainly controlled by climatic conditions, and overly independent of flow. Subaerial processed are often called â€Å"preparatory processes† due to they increase the susceptibility of soil to erosion at high flows (Wolman, 1959;Lawler, 1993) Apparently. Fluvial entrainment means the direct removal of soil particles or aggregates from the streambed or banks by flowing water. (Tess Wynn 2006), but the fluvial erosion of cohesive soils is extremely complex and related to soil properties and test conditions (Grissinger, 1982). The susceptibility of a cohesive soil to erosion influenced by numerous of the parameters of soil, including grain size distribution, soil density, pore water content and chemistry (Grissinger, 1982) Mass wasting also known as bank failure, it occurs when the weight of the bank exceeds the shear strength of soil. The mass wasting can be attributed to increasing the bank height or bank angel due to fluvial erosion or the presence of tension cracks (ASCE, 1998).Research has proved that bank geometry, properties of bank materials and the density and the type of bank vegetation play the key role the occurrence of mass wasting. Hu Liu, Theodore G. Cleveland, and Keh Han Wang conducted the laboratory tests of dependence on properties of soils and. In their study, rainfall was generated by the rainfall simulator; along with flume .The rainfall simulator consist of a wooden frame and a group of PVC pipes with small holes. The soil sample was placed at one end of the flume .In the experiment, the simulator activated by the adjustment of the slope. In addition, six type of soil with different texture and classifications used in this laboratory experiments. The results show more soil erosion produced by the higher rainfall intensity. Besides, the unit soil volume loss affected by shear strength, compressive strength and rainfall intensities but less influenced by the bed slope. (Hu Liu, Theodore G. Cleveland, and Keh Han Wang, 1999) Jill Fernqvist and Ida Florberger conducted their research in South Africa .Their study indicated the fires are one the important factor that changes the soil properties .their study has been taken in the Western Cape,. The fieldwork focused on water repellency has detrimental influence upon the post-fire erosion Jill Fernqvist and Ida Florberger(2003) 2 Soil Erodibility Soil erodibility is an estimate of the ability of soils to resist erosion in term of the physical characteristics of soil. Generally, the faster infiltration rates of soil, the higher levels of organic matter and improved soil structure have a greater resistance to erosion silt, very fine sand, and certain clay textured soils tend to be more erodible than Sand, sandy loam and loam textured soils cropping practices which lower soil organic matter levels, cause poor soil structure, and result of compacted contribute to increases in soil erodibility. Compacted subsurface soil layers result in decreased infiltration and increased runoff. A formation of a soil crust, can create the decreased of infiltration, however, normally the growth of runoff water is attended by the greater soil erosion problems. (BC.S.Baldwin 2003) There is a definite link between Past erosion and soils. The original soils tend to be less erodible than the exposed subsurface soils on eroded sites were, owing to their lower organic matter or poorer structure .The lower nutrient levels usually related with subsoils contribute to lower crop yields and generally poorer crop cover, which in turn provides less crop protection for the soil. (BC.S.Baldwin 2003) Gregory J. Hanson provided the complex problem about how to predict the erodibilty of soil material by flowing water. Base on the knowledge of hydraulic characteristics and the characteristics of cohesive soils .Laboratory Jet tests were carried out on soil samples compacted at different moisture content dynamic. Jet detection apparatus and method description of the excess stress parameters determined kd and tc. An example of this is used to test the soil in the laboratory to determine the appropriate placement in the field. The flume tests and field trials were carried out to verify the plane corrosion. (Gregory J.2002) 3 Slope Gradients and Length Basically. The steeper slope areas, the greater amount of soil erosion by water.Soil erosion of water also increased with slope length due to the greater accumulation of runoff. The consolidation of small fields into larger results is often no longer the slope length of the potential for erosion, because water with an increase rate that allows a greater degree of scouring (carrying capacity of the sediment) (BC.S.Baldwin 2003) 4 Soil Deposition Soil particles of all sizes may be moved during run-off. When flow stopped, these start to settle. According to the US Environmental Protection Agency (USEPA), sediment is a root cause of water quality impairment (USEPA, 2002).excess Suspended sediments to reduce diversity and rich of aquatic organisms, reduce reservoir capacity, improve drinking water treatment costs, and serve as a carrier of pollutants.(Tess Wynn,2006) The erosion process of cohesive sediment was studied in Masato Sekine and Nobuaki Iizuka study .To full understand the process, they also conduct an experiment .Clay mixed with different compositions were used to test samples of the form of erosion of water pipes in a closed experimental apparatus. Specifically .Experiments carried out a square circle closed pipeline system cross-section 400 centimeters in length and 10 centimeters wide, 10 centimeters deep. 5 Vegetation The potential of soil erosion is increased, if the soil with little or no vegetation, plants and crop residues. Residue cover to protect plants and soil from rain splash, tends to slow down surface runoff flows, and ensures excess surface water infiltration. Erosion soils reducing the efficiency of the plant or residue cover depends on the category, degree and quantity of cover. Combination of vegetation and residue completely covered the soil, and to intercept all falling raindrops, and near the surface and the most effective control of soil (such as forests, permanent grassland). Part into the residue and the root is also very important because they provide the channel that allows surface water into the soil. The effectiveness of any crop, management system or protective cover also depends on how much protection can be at different times during the year, the relative amount of erosive rainfall during these periods belong to. In this aspect , the crops with food, protective cover a major part of the year (for example, alfalfa or winter cover crops) can reduce soil erosion can be far more than crops leave the soil bare for a longer period of time (such as row crops) , especially during the high erosive rainfall (spring and summer).( C.S.Baldwin 2003) I.J. Shelton also investigated tillage operations influence upon the soil erosion, which depending on the depth, direction and timing of the plowing, the types of farming equipment and a number of passes. Generally speaking, the less interference or residual vegetation cover at or near the surface, the more efficient farming practices, and reduce soil erosion (I.J. Shelton 2003) Soil erosion potential is affected by tillage operations, depending on the depth, direction and timing of plowing, the type of tillage equipment and the number of passes. Generally, the less the disturbance of vegetation or residue cover at or near the surface, the more effective the tillage practice in reducing erosion. Regarding the effects of vegetation on streambank stability , Tess Wynn examined the vegetation influences the chemical and properties of steambanks and the local micro climate .The multiple effects on subaerial process produced by riparian vegetation including the dense cover of vegetation absorbs the energy of rainfall ,reducing soil detachment by raindrop . But it should be noted that the effects of vegetation on stream hydraulic varies with the stream stage, width and season. Additionally. Distribution of energy and sediment in a stream influenced by the vegetation. (Tess Wynn 2006) Tess Wynn 2006 addressed the vegetation cover problem. Extensive erosion by wind may result from the lack of permanent vegetation cover in certain locations. Loose, dry, bare soil is the most susceptible; however, crops that produce low levels of residue also may not provide enough resistance. Besides, crops that produce a lot of residue which not protect the soil in severe conditions. Therefore, an adequate network of living windbreaks along with good tillage, residue management, and crop selection are considered to be the most effective vegetative cover for protection. (Tess Wynn 2006) South Africa is a country which lack of the water, but the Jill Fernqvist and Ida Florberger have described the theory of fire -induced water repellency and the following soil erosion in their study. Generally, In South Africa, alien species require more water than the indigenous one. Therefore, alien vegetation provides a poor ground cover compared to the indigenous vegetation, which could result in surface run off and soil erosion (.Jill Fernqvist and Ida Florberger 1996). Jill Fernqvist and Ida Florberger observed the Alien vegetation apparently has been considered as a key issue in the ecosystem of Western Cape. Water yield was decreased in the long term due to the alien vegetation consume a large amount of water, as a result, the biodiversity is threatened. In addition, fire in the alien vegetation for the results of erosion-prone slopes. (Jill Fernqvist and Ida Florberger, 2003) Defra (2005) summarized the Management Practices using Vegetables and Salad Crops in soil erosion Control. And offered some solutions to prevent the soil erosion when undertaking the cultivations, irrigation and harvest. (Defra 2005) 6 Soil Erosion by Wind Soil is also erosion by wind, although the effect is not noticeable like the erosion by water. C.S.Baldwin studied the rate and magnitude of soil erosion by wind is decided by many factors: Erodibility of Soil The wind suspends very fine particles and then transported great distances. Fine and medium size particles can be lifted and deposited by wind. While coarse particles can be blown along the surface (commonly known as the saltation effect). Soil Surface Roughness Soil surfaces only provide little resistance to the wind. However, ridges can be filled in and the roughness broken down by abrasion to produce a smoother surface susceptible to the wind in a long time. Excess tillage is a threat to soil, because it breakdown the soil structure and increased erosion. Climate There is a define link between the speed and duration of the wind and extent of soil erosion. The levels of Soil moisture can be very slightly low at the surface of excessively drained soils or during periods of dro ught, and releasing the particles for transport by wind. It occurs in freeze drying of the surface in winter. Adverse operating conditions maybe created by wind erosion in the field. Crops can be completely ruined so that costly delay and reseeding is necessary (C.S.Baldwin 2003) 7 Effects of Soil Erosion The negative changes from bank erosion including farmland productivity losses, damage to building structures such as bridges, roads etc. I.J. Shelton defined the on-site effects and off-site effects. On-site effects mean extension of the elimination of the impact of soil erosion of valuable topsoil. Crop emergence, growth and yield a direct impact on the loss of, natural and applied fertilizer and soil nutrients. Seeds and plants may interfere with or completely abolish the erosion site. Organic matter in soil, residues and any applicable fertilizer, a relatively light weight, can be transported off-site, especially in the spring thaw conditions. While the off-site effect is not always obvious as on-site effects, but Eroded soil, deposited down slope can inhibit or delay the emergence of the seed, bury small seedling, need to replant in the affected areas. Soil quality, structure, stability and texture can be affected by the loss of soil. The breakdown of aggregates and the removal o f smaller particles or entire layers of soil or organic matter can weaken the structure and even change the texture. Textural changes can in turn affect the water-holding capacity of the soil, making it more susceptible to extreme condition such a drought. (I.J. Shelton 2003) According to the C.S.Baldwin (2003), Sediment can contribute to road damage, accelerate bank erosion, and reduce downstream water quality. What is worse, Pesticides, and fertilizers, which contained in the soils. They frequently transported with eroded soil pollution or contamination of water downstream and entertainment district. 8 Conservation Measures While, based upon research, various conservation measures can be taken to reduce soil erosion by both water and wind. Tillage, cropping practices, and land management practices, have a direct impact on the overall soil erosion problem and solutions to a farm. When crop rotations or changing tillage practices are not enough areas where erosion control method or a combination of more extreme measures may be necessary. For example, contour plowing, strip cropping, or terracing may be considered. (C.S.Baldwin 2003) The defra (2005) advised measures about how to control the soil erosion. In their study, four categories of solution were presented. It is crucial to understand that erosion control on susceptible soil types can be successfully achieved to reduce the impact of rainfall erosion and maintain soil infiltration rate, so that the surface flow are avoided. It can be achieved by 1 To protect the soil from rainfall impact, whether it is permanent vegetation cover or land rotation, timely crop establishment and retention of surface crop residues. 2 Avoiding smooth, flat finishes to exposed field surfaces, so that good water seepage rates remain unchanged. 3 Avoiding tramlines, wheeling or cultivation features that can channel surface flow. 4 Seeking to increase the organic matter content in the means of improving the stability of the soil in the longer term. Steep slope and erosion because of increased risk, the efficiency of these measures is becoming increasingly important. When deciding on the combination of measures to apply in any particular situation, consideration should always be the serious erosion that may occur, if the case happened. In some cases, a measure aimed at controlling erosion may increase. For example, work along the contour is sometimes used to reduce runoff, but if the profile is not strictly followed, the accumulation of water at low points which might break over the cultivation features. (Defra 2005) Meanwhile, good management practices play a pivotal role in the control of soil erosion. Some examples and considerations were presented in defra (2005) study. In order to minimize the soil erosion when soil in the most vulnerable condition, the different type and timing of cultivations should be planned. Obviously, the overall aim should be the soil maintain in a less vulnerable condition as long as possible .Therefore, defra (2005) provided the good management of the farm to reduce erosion risks in terms of seedbed preparation, directions of cultivations and irrigation. 9 Conclusion Soil erosion is a natural and slow process. It has the detrimental effect on the environmental. Normally the agents of soil erosion are water and wind, the soil erosion is affected by many factors .But soil erosion could be effectively controlled and minimized by taken appropriate measures. References Abernethy, B. and I. D. Rutherfurd. 1998. Where along a rivers length will vegetation most effectively stabilize stream banks? Geomorphology. 23(1):55-75 ASCE. 1998. River width adjustment. I: Processes and mechanisms. Journal of Hydraulic Engineering. 124(9):881-902. Coppin, N. J. and I. G. Richards. 1990. Use of Vegetation in Civil Engineering. Butterworths.London Department for environment food and rural affairs .2005 .Controlling soil erosion, Defra Publications, London. G.J.de Boer .2002.on the consolidation and erosion of cohesive sediments.Deflt University of Technology .Civil Engineering and Geosciences G. Wall, C.S. Baldwin and I.J. Shelton. 2003. Soil Erosion Causes and Effects .Face Sheet.Queen`s print for Ontario Jill Fernqvist, Ida Florberger 2003. Fire and post-fire soil erosion in the Western Cape, South Africa: Field observations and management practices. Committee of Tropical Ecology, Uppsala University, Sweden. Tess Wynn.2006. Streambank Retreat: A Primer. Vol. 4, No.1 January March 2006. Watershed Update Thorne, C. R. and N. K. Tovey. 1981. Stability of composite river banks. Earth Surface Processes and Landforms. 6(5):469-484

Forced Vibrations Of Simple Systems English Language Essay

Forced Vibrations Of Simple Systems English Language Essay Mechanical, acoustical, or electrical vibrations are the sources of sound in musical instruments. Some familiar examples are the vibrations of strings violin, guitar, piano, etc, bars or rods xylophone, glockenspiel, chimes, and clarionet reed, membranes (drums, banjo), plates or shells (cymbal, gong, bell), air in a tube (organ pipe, brass and woodwind instruments, marimba resonator), and air in an enclosed container (drum, violin, or guitar body). In most instruments, sound production depends upon the collective behavior of several vibrators, which may be weakly or strongly coupled together. This coupling, along with nonlinear feedback, may cause the instrument as a whole to behave as a complex vibrating system, even though the individual elements are relatively simple vibrators (Hake and Rodwan, 1966). In the first seven chapters, we will discuss the physics of mechanical and acoustical oscillators, the way in which they may be coupled together, and the way in which they radiate sound. Since we are not discussing electronic musical instruments, we will not deal with electrical oscillators except as they help us, by analogy, to understand mechanical and acoustical oscillators. According to Iwamiya, Kosygi and Kitamura (1983) many objects are capable of vibrating or oscillating. Mechanical vibrations require that the object possess two basic properties: a stiffness or spring like quality to provide a restoring force when displaced and inertia, which causes the resulting motion to overshoot the equilibrium position. From an energy standpoint, oscillators have a means for storing potential energy (spring), a means for storing kinetic energy (mass), and a means by which energy is gradually lost (damper). vibratory motion involves the alternating transfer of energy between its kinetic and potential forms. The inertial mass may be either concentrated in one location or distributed throughout the vibrating object. If it is distributed, it is usually the mass per unit length, area, or volume that is important. Vibrations in distributed mass systems may be viewed as standing waves. The restoring forces depend upon the elasticity or the compressibility of some mater ial. Most vibrating bodies obey Hookes law; that is, the restoring force is proportional to the displacement from equilibrium, at least for small displacement. Simple harmonic motion in one dimension: Moore (1989) has mentioned that the simplest kind of periodic motion is that experienced by a point mass moving along a straight line with an acceleration directed toward a fixed point and proportional to the distance from that point. This is called simple harmonic motion, and it can be described by a sinusoidal function of time, where the amplitude A describes the maximum extent of the motion, and the frequency f tells us how often it repeats. The period of the motion is given by That is, each T seconds the motion repeats itself. Sundberg (1978) has mentioned that a simple example of a system that vibrates with simple harmonic motion is the mass-spring system shown in Fig.1.1. We assume that the amount of stretch x is proportional to the restoring force F (which is true in most springs if they are not stretched too far), and that the mass slides freely without loss of energy. The equation of motion is easily obtained by combining Hookes law, F = -Kx, with Newtons second law, F = ma =. Thus, and Where = The constant K is called the spring constant or stiffness of the spring (expressed in Newtons per meter). We define a constant so that the equation of motion becomes This well-known equation has these solutions: ) Figure 2.1: Simple mass-spring vibrating system Source: Cremer, L., Heckl, M., Ungar, E (1988), Structure-Borne Sound, 2nd edition, Springer Verlag Figure 2.2: Relative phase of displacement x, velocity v, and acceleration a of a simple vibrator Source: Campbell, D. M., and Greated, C (1987), The Musicians Guide to Acoustics, Dent, London or From which we recognize as the natural angular frequency of the system. The natural frequency fo of our simple oscillator is given by and the amplitude by or by A; is the initial phase of the motion. Differentiation of the displacement x with respect to time gives corresponding expressions for the velocity v and acceleration a (Cardle et al, 2003): , And . Ochmann (1995) has mentioned that the displacement, velocity, and acceleration are shown in Fig. 1.2. Note that the velocity v leads the displacement by radians (90), and the acceleration leads (or lags) by radians (180). Solutions to second-order differential equations have two arbitrary constants. In Eq. (1.3) they are A and; in Eq. (1.4) they are B and C. Another alternative is to describe the motion in terms of constants x0 and v0, the displacement and velocity when t =0. Setting t =0 in Eq. (1.3) gives and setting t = 0 in Eq. (1.5) gives From these we can obtain expressions for A and in terms of xo and vo: , and Alternatively, we could have set t= 0 in Eq. (1.4) and its derivative to obtain B= x0 and C= v0/ from which . 2.3 Complex amplitudes According to Cremer, Heckl and Ungar (1990) another approach to solving linear differential equations is to use exponential functions and complex variables. In this description of the motion, the amplitude and the phase of an oscillating quantity, such as displacement or velocity, are expressed by a complex number; the differential equation of motion is transformed into a linear algebraic equation. The advantages of this formulation will become more apparent when we consider driven oscillators. This alternate approach is based on the mathematical identity where j =. In these terms, Where Re stands for the real part of. Equation (1.3) can be written as, Skrodzka and Sek (2000) has mentioned that the quantity is called the complex amplitude of the motion and represents the complex displacement at t=0. The complex displacement is written The complex velocity and acceleration become Desmet (2002) has mentioned that each of these complex quantities can be thought of as a rotating vector or phase rotating in the complex plane with angular velocity, as shown in Fig. 1.3. The real time dependence of each quantity can be obtained from the projection on the real axis of the corresponding complex quantities as they rotate with angular velocity Figure 2.3: Phase representation of the complex displacement, velocity, and acceleration of a linear oscillator Source: Bangtsson E, Noreland D and Berggren M (2003), Shape optimization of an acoustic horn, Computer Methods in Applied Mechanics and Engineering, 192:1533-1571 2.4 Continuous systems in one dimension Strings and bars This section focuses on systems in which these elements are distributed continuously throughout the system rather than appearing as discrete elements. We begin with a system composed of several discrete elements, and then allow the number of elements to grow larger, eventually leading to a continuum (Karjalainen and Valamaki, 1993). Linear array of oscillators According to Mickens (1998) the oscillating system with two masses in Fig. 1.20 was shown to have two transverse vibrational modes and two longitudinal modes. In both the longitudinal and transverse pairs, there is a mode of low frequency in which the masses move in the same direction and a mode of higher frequency in which they move in opposite directions. The normal modes of a three-mass oscillator are shown in Fig. 2.1. The masses are constrained to move in a plane, and so there are six normal modes of vibration, three longitudinal and three transverse. Each longitudinal mode will be higher in frequency than the corresponding transverse mode. If the masses were free to move in three dimensions, there would be 3*3 =9 normal modes, three longitudinal and six transverse. Increasing the number of masses and springs in our linear array increases the number of normal modes. Each new mass adds one longitudinal mode and (provided the masses move in a plane) one transverse mode. The modes of transverse vibration for mass/spring systems with N=1 to 24 masses are shown in Fig. 2.2; note that as the number of masses increases, the system takes on a wavelike appearance. A similar diagram could be drawn for the longitudinal modes. Figure 2.4: Normal modes of a three-mass oscillator. Transverse mode (a) has the lowest frequency and longitudinal mode (f) the highest Source: Jaffe, D and Smith, J (1983), Extension of the Karplus-Strong plucked string algorithm, CMJ 7:2, 43-45 Figure 2.5: Modes of transverse vibration for mass/spring systems with different numbers of masses. A system with N masses has N modes Source: Beranek L (1954), Acoustics. McGraw-Hill, New York As the number of masses in our linear system increases, we take less and less notice of the individual elements, and our system begins to resemble a vibrating string with mass distributed uniformly along its length. Presumably, we could describe the vibrations of a vibrating string by writing N equations of motion for N equality spaced masses and letting N go to infinity, but it is much simpler to consider the shape of the string as a whole (Bogoliubov, and Mitropolsky, 1961). Standing waves Consider a string of length L fixed at x=0 and x= L. The first condition y (0,t) = 0 requires that A = -C and B = -D in Eq. (2.9), so Using the sum and difference formulas, sin(xy) = sin x cos y cos x sin y and cos(x Y = 2A sin kx cos = 2[A cos The second condition y (L, t) =0 requires that sin kL =0 or . This restricts to values Thus, the string has normal modes of vibration (Obrien, Cook and Essl, 2001): These modes are harmonic, because each fn is n times f1= c/2L. The general solution of a vibrating string with fixed ends can be written as a sum of the normal modes: and the amplitude of the nth mode is. At any point Alternatively, the general solution could be written as Where Cn is the amplitude of the nth mode and is its phase (Keefe and Benade, 1982). 2.5 Energy of a vibrating string McIntyre et al (1981) has mentioned that when a string vibrates in one of its normal modes, the kinetic and potential energies alternately take on their maximum value, which is equal to the total energy. Thus, the energy of a mode can be calculated by considering either the kinetic or the potential energy. The maximum kinetic energy of a segment vibrating in its nth mode is: Integrating over the entire length gives The potential and kinetic energies of each mode have a time average value that is En/2. The total energy of the string can be found by summing up the energy in each normal mode: Plucked string: time and frequency analyses According to Laroche and Jot (1992) when a string is excited by bowing, plucking, or striking, the resulting vibration can be considered to be a combination of several modes of vibration. For example, if the string is plucked at its center, the resulting vibration will consist of the fundamental plus the odd-numbered harmonics. Fig. 2.5 illustrates how the modes associated with the odd-numbered harmonics, when each is present in the right proportion; add up at one instant in time to give the initial shape of the center-plucked string. Modes 3,7,11, etc., must be opposite in phase from modes, 1, 5, and 9 in order to give maximum displacement at the center, as shown at the top. Finding the normal mode spectrum of a string given its initial displacement calls for frequency analysis or fourier analysis. Figure 2.6: Time analysis of the motion of a string plucked at its midpoint through one half cycle. Motion can be thought of as due to two pulses travelling in opposite directions Source: Gokhshtein, A. Y (1981), Role of air ¬Ã¢â‚¬Å¡ow modulator in the excitation of sound in wind instruments, Sov. Phys. Dokl. 25, 954-956 Since all the modes shown in Fig.2.6 have different frequencies of vibration, they quickly get out of phase, and the shape of the string changes rapidly after plucking. The shape of the string at each moment can be obtained by adding the normal modes at that particular time, but it is more difficult to do so because each of the modes will be at a different point in its cycle. The resolution of the string motion into two pulses that propagate in opposite directions on the string, which we might call time analysis, is illustrated in Fig.2.6 if the constituent modes are different, of course. For example, if the string is plucked 1/5 of the distance from one end, the spectrum of mode amplitudes shown in Fig. 2.7 is obtained. Note that the 5th harmonic is missing. Plucking the string  ¼ of the distance from the end suppresses the 4th harmonic, etc. (Pavic, 2006). Roads (1989) have mentioned that a time analysis of the string plucked at 1/5 of its length. A bend racing back and forth within a parallelogram boundary can be viewed as the resultant of two pulses (dashed lines) travelling in opposite directions. Time analysis through one half cycle of the motion of a string plucked one-fifth of the distance from one end. The motion can be thought of as due to two pulses moving in opposite directions (dashed curves). The resultant motion consists of two bends, one moving clockwise and the other counter-clockwise around a parallelogram. The normal force on the end support, as a function of time, is shown at the bottom. Each of these pulses can be described by one term in dAlemberts solution [Eq. (2.5)]. Each of the normal modes described in Eq. (2.13) has two coefficients and Bn whose values depend upon the initial excitation of the string. These coefficients can be determined by Fourier analysis. Multiplying each side of Eq. (2.14) and its time derivative by sin mx/L and integrating from 0 to L gives the following formulae for the Fourier coefficients: By using these formulae, we can calculate the Fourier coefficients for the string of length L is plucked with amplitude h at one fifth of its length as shown in figure.2.8 time analysis above. The initial conditions are: y (x,0) = 0 y (x,0) = 5h/L .x, 0 x L/5, = 5h/4 (1-x/L), L/5 x L. Using the first condition in first equation gives An=0. Using the second condition in second equation gives = = The individual Bns become: B1 =0.7444h, B2 =0.3011h, B3 =0.1338h, B4 =0.0465h, B5 =0, B6= -0.0207h, etc. Figure 2.7 shows 20 log for n=0 to 15. Note that Bn=0 for n=5, 10, 15, etc., which is the signature of a string plucked at 1/5 of its length (Shabana, 1990). Bowed string Woodhouse (1992) has mentioned that the motion of a bowed string has interested physicists for many years, and much has been written on the subject. As the bow is drawn across the string of a violin, the string appears to vibrate back and forth smoothly between two curved boundaries, much like a string vibrating in its fundamental mode. However, this appearance of simplicity is deceiving. Over a hundred years ago, Helmholtz (1877) showed that the string more nearly forms two straight lines with a sharp bend at the point of intersection. This bend races around the curved path that we see, making one round trip each period of the vibration. According to Chaigne and Doutaut (1997) to observe the string motion, Helmholtz constructed a vibration microscope, consisting of an eyepiece attached to a tuning fork. This was driven in sinusoidal motion parallel to the string, and the eyepiece was focused on a bright-colored spot on the string. When Helmholtz bowed the string, he saw a Lissajous figure. The figure was stationary when the tuning fork frequency was an integral function of the string frequency. Helmholtz noted that the displacement of the string followed a triangular pattern at whatever point he observed it, as shown in Fig.2.7: Figure 2.7: Displacement and Velocity of a bowed string at three positions along the length: a) at x = L/4; b) at the center, and c) at x = 3L/4 Source: Smith, J (1986), Efficient Simulation of the Reed-Bore and Bow-String Mechanisms, Proc. ICMC, 275-280 The velocity waveform at each point alternates between two values. Other early work on the subject was published by Krigar-Menzel and Raps (1891) and by Nobel laureate C. V. Raman (1918). More recent experiments by Schelleng (1973), McIntyre, et al. (1981). Lawergren (1980), Kondo and Kubata (1983), and by others have verified these early findings and have greatly added to our understanding of bowed strings. An excellent discussion of the bowed string is given by Cremer (1981). The motion of a bowed string is shown in Fig.2.8: Figure 2.8: Motion of a bowed string. A) Time analysis of the motion showing the shape of the string at eight successive times during the cycle. B) Displacement of the bow (dashed line) and the string at the point of contact (solid line) at successive times. The letters correspond to the letters in (A) Source: McIntyre, M., Woodhouse, J (1979), On the Fundamentals of Bowed-String Dynamics, Acustica 43:2, 93-108 Dobashi, Yamamoto and Nishita (2003) have described that a time analysis in the above figure 2.8 (A) shows the Helmholtz-type motion of the string; as the bow moves ahead at a constant speed, the bend races around a curved path. Fig. 2.8 (B) shows the position of the point of contact at successive times; the letters correspond to the frames in Figure 2.8(A). Note that there is a single bend in the bowed string. Whereas in the plucked string (fig. 2.8), we had a double bend. The action of the bow on the string is often described as a stick and slip action. The bow drags the string along until the bend arrives [from (a) in figure 2.8 (A)] and triggers the slipping action of the string until it is picked up by the bow once again [frame (c)]. From (c) to (i), the string moves at the speed of the bow. The velocity of the bend up and down the string is the usual . The envelope around which the bend races [the dashed curve in Figure 2.8 (A)] is composed of two parabolas with maximum amplitu de that is proportional, within limits, to the bow velocity. It also increases as the string is bowed nearer to one end. 2.6 Vibration of air columns: According to Moore and Glasberg (1990) the familiar phenomenon of the sound obtained by blowing across the open and of a key shows that vibrations can be set up in an air column. An air column of definite length has a definite natural period of vibrations. When a vibrating tuning fork is held over a tall glass is pured gradually, so as to vary the length of the air column, a length can be obtained which will resound loudly to the note of the tuning fork. Hence it is the air column is the same as that of the tuning fork. A vibration has three important characteristics namely Frequency Amplitude Phase 2.6.1 Frequency:- Frequency is defined as the number of vibration in one second. The unit is Hertz. It is normally denoted as HZ. Thus a sound of 1000 HZ means 1000 vibrations in one second. A frequency of 1000 HZ can also be denoted as 1 KHZ. If the frequency range of audio equipment is mentioned as 50 HZ to 3 HZ it means that audio equipment will function within the frequency range between 50HZ and 3000 HZ. 2.6.2 Amplitude:- Amplitude is defined as the maximum displacement experienced by a particle in figure will help to understand amplitude. Let us consider two vibrating bodies having the same frequency but different amplitudes. The body vibrating with more amplitude will be louder than the body vibrating with less amplitude. The following figure represents two vibrating bodies having the same frequency but different amplitudes (Takala and Hahn, 1992). 2.6.3 Phase:- Phase is defined as the stage to which a particle has reached in its vibration. Initial phase means the initial stage from which the vibration starts. The following will help to understand the concept of phase. From the source travels in the form of waves before reaching the ear sound cannot travel in vacuum. Sound needs medium for its travel. The medium may be a solid or liquid or gas (Brown and Vaughn, 1993). Support a glass tube open at both ends in a vertical position, with its lower and dipping into water contained in a wider cylinder. Hold over the upper end of the tube a vibrating tuning form. Adjust the reinforcement of the sound is obtained. Adjust the distance of the air column till we get actually the resonance or sympathetic note. Repeat the adjustments and take the average of the results from the observation. It will be found from the repeated experiments, that the longer the air column is produced when the tuning fork becomes identical. Vibration of air column in a tube open at both ends:- Obrien, Shen and Gatchalian (2002) have described that if they think of an air column in a tube open both ends, and try to imagine the ways in which it can vibrate; we shall readily appreciate that the ends will always be antinodes, since here the air is free to move. Between the antinodes there must be at least one node, and the ends, the moving air is either moving towards the center from both ends or away from the centre at both ends. Thus the simplest kind of vibration has a node at the centre and antinodes at the two ends. This can be mathematically expressed as follows: Wave length of the simplest kind of vibration is four times the distance from node to antinode 2L where L is the length of the pipe. Vibration of air column in a tube closed at one end: The distance from node to antinode in this case is L, the whole length of the pipe, the wavelength is therefore = 4L. 2.7 Resonance-sympathetic vibration Sloan, Kautz and Synder (2002) have described that everybody which is capable of vibration has natural frequency of its own. When a body is made to vibrate at its neutral frequency, it will vibrate with maximum amplitude. Resonance is a phenomenon in which a body at rest is made to vibrate by the vibrations of another body whose frequency is equal to that of the natural frequency of the first. Resonance can also be called sympathetic vibrations. The following experiment will help to understand resonance: Consider two stretched stings A and B on a sonometer. With the help of a standard tuning form we can adjust their vibrating lengths [length between the bridges] to have the same frequency. Thus we can place a few paper riders on string B and pluck string A to make it vibrate. The string B will start vibrate and paper riders on it will flutter vigorously and sometimes A can be stopped simply by touching it. Still the string B will continue to vibrate. The vibration in the string B is due to resonance and it can be called as sympathetic vibration. If instead of the fundamental frequency one of the harmonics of string B is equal to the vibrating frequency of string A then the string B will start vibrating at that harmonics frequency. But in the case of harmonics the amplitude of vibration will be less. In Tambura when the sarani is sounded the anusarani also, vibrates thus helping to produce a louder volume of sound. The sarani here makes the anusarani to vibrate. In all musical instrum ents the material, the shape of the body and enclosed volume of air make use of resonance to bring out increased volume and desired upper partials of harmonics. 2.8 Intonations Spiegel and Watson (1984) have described that during the course of the history of music, several of music intervals were proposed aiming at a high degree of maturing consonance and dissonance played important role in the evolution of musical scales. Just intonation is the result of standardizing perfect intervals. Just Intonation is limited to one single-key and aims at making the intervals as accordant as possible with both one another and with the harmonics of the keynote and with the closely related tones. The frequency ratio of the musical notes in just Intonation is given below. Indian note Western note Frequency ratio r C 1 K2 D 9/8 f2 E 5/4 M1 F 4/3 P G 3/2 D2 A 5/3 N2 B 15/8 S C 2 Ward (1970) has mentioned that most of the frequency ratios are expressed is terms of comparatively small numbers. Constant harmonics are present when frequency ratios are expressed in terms of small numbers. The interval in frequency ratio are: Between Madhya sthyai C[Sa] and Tara sthayi c[sa] is 2 [1*2=2]. Between Madhya sthyai C[Sa] and Madhya sthayi G[pa] is 3/2 [1*3/2=3/2]. Between Madhya sthayi D[Ri] and Madhya sthayi E[Ga] is 10/9 [9/8*10/9=5/4] Between Madhya sthyai E[Ga] and Madhya sthayi F[Ma] is 16/15-[5/4*16/15=4/3]. Between Madhya sthyai F[Ma] and Madhya sthayi G[Pa] is 9/8-[4/3*9/8=3/2]. Between Madhya sthyai G[Pa] and Madhya sthayi A[Dha] is 10/9[3/2*10/9=5/3]. Between Madhya sthyai A[Dha] and Madhya sthayi B[Ni] is 9/8-[5/3*9/8=5/8]. Between Madhya sthyai Sa[C] and Ri2[D] there is a svarasthanam [CH]. Hence the interval between Sa[C] and Ri2[D] and Ga2[E] is known as a tone. But there is no svarasthanam [semitone] between Ga2[E] and Ma1[F]. Hence the interval between Ga[E] and Ma1[F] is known as a semitone. Between Pa[G] and Dha[A] we have a tone. Between mathya styayi Ni2[B] and Tara sthyai C[Sa] we have a semitone. In just Intonation we find that tones are not all equal. But the semitones are equal. In just Intonation the modulation of key of musical notes will be difficult for example, if the keynote is changed from Sa[C] to Pa[G] then the frequency of etatusruthi Dhairatam [A] will change from 1.687, time the frequency of Sa[c]. A musical instrument tuned in just intonation to play sankarabaranam ragam cannot be used to play kalyani ragam. Hence the modulation of key of musical notes will be difficult in just Intonation (Doutaut , Matignon, and Chaigne, 1998). Equal temperature Lehr (1997) has described that the above mentioned problem in just Intonation can be solved in the Equal Temperament scale. In Equal temperament all the 12 music intervals in a sthayi [octave] are equal. The frequency ratios of semitones in Equal temperament scale was first calculated by the French Mathematician Mersenne and was published in Harmonic Universelle in the year 1636. But it was not put into use till the latter half of seventeenth century. All keyboard instruments are tuned of Equal Temperature scale. Abraham pandithar strongly advocated Equal Temperament scale and in his famous music treatise karunamitha sagaram he tried to prove that the Equal Temperament scale was in practice in ancient Tamil music. A simple mathematical exercise will help to under the basis of Equal Temperament scale. Equal Temperament Madhya sthayi Sa[c] frequency ratio=1=2 ÃÅ'Ã…  . Tara sthayi Sa[i] frequency ratio = 2=212/12=2. Frequency ratios of 12 svarasthanams are given below. S R1 R2 G1 G2 M1 M2 P D1 D2 N1 N2 à ¢Ã¢â‚¬  Ã¢â‚¬Å" à ¢Ã¢â‚¬  Ã¢â‚¬Å" à ¢Ã¢â‚¬  Ã¢â‚¬Å" à ¢Ã¢â‚¬  Ã¢â‚¬Å" à ¢Ã¢â‚¬  Ã¢â‚¬Å" à ¢Ã¢â‚¬  Ã¢â‚¬Å" à ¢Ã¢â‚¬  Ã¢â‚¬Å" à ¢Ã¢â‚¬  Ã¢â‚¬Å" à ¢Ã¢â‚¬  Ã¢â‚¬Å" à ¢Ã¢â‚¬  Ã¢â‚¬Å" à ¢Ã¢â‚¬  Ã¢â‚¬Å" à ¢Ã¢â‚¬  Ã¢â‚¬Å" 20 21/12 22/12 23/12 24/12 25/12 26/12 27/12 28/12 29/12 210/12 2n/12 S à ¢Ã¢â‚¬  Ã¢â‚¬Å" 212/12 All semitones are equal is Equal Temperament scale. Each represents the same frequency ratio 1.05877. The great advantage in Equal Temperament scale is that music can be played equal well in all keys. This means that any of the 12 semitones can be used as Sa in a music instrument tuned to Equal Temperament scale. There is no need to change tuning every time the Raga is changed. Since keyboard instruments are pre-tuned instruments they follow Equal Temperament. 2.9 Production and transmission of sound:- According to Boulanger (2000) the term sound is related to quite definite and specific sensation caused by the stimulation of the mechanism of the ear. The external cause of the sensation is also related to sound. Anybody in vibration is an external cause of the sensation. A veena [after plucking] or violin [after blowing] in a state of vibration is an external cause of the sensation. A body in a state of vibration becomes a source of sound. A vibration is a periodic to and fro motion about a fixed point Iwamiya and Fujiwara (1985) have mentioned that the pitch of a musical sound produced on a wind instrument depends on the rate or frequency of the vibrations which cause the sound. In obedience to Natures law, the column of air in a tube can be made to vibrate only at certain rates, therefore, a tube of any particular length can be made to produce only certain sounds and no others as long as the length of the tube is un-altered. Whatever the length of the tube, these various sounds always bear the same relationship one to the other, but the actual pitch of die series will depend on the length of the tube. The player on a wind instrument, by varying the intensity of the air-stream which he injects into the mouthpiece, can produce at will all or some of the various sounds which that particular length of tube is capable of sounding; thus, by compressing the air-stream with his lips he increases the rate of vibration and produces higher sounds, and by decompressing or slackening the inte nsity of the air-stream he lowers the rate of vibration and produces lower pitched sounds. In this way the fundamental, or lowest note which a tube is capable of sounding, can be raised becoming higher and higher by intervals which become smaller and smaller as they ascend. These sounds are usually called harmonics or upper partials, and it is convenient to refer to them by number, counting the fundamental as No. t, the octave harmonic as No. 2, and so on. The series of sounds available on a tube approximately 8 feet in length is as follows: Tsingos et al (2001) has mentioned that a longer tube would produce a corresponding series of sounds proportionately lower in pitch according to its length, and on a shorter tube the same series would be proportionately higher. The entire series available on any tube is an octave lower than that of a tube half its length, or an octave higher than that of a tube double its length ; thus, the approximate lengths of tube required to sound the various notes C are as follows : Fundamental Length of tube C, 16 feet C 8 ,. c 4,, c 2,, c I foot c 1/2,, Shonle and Horen (1980) has mentioned that the addition of about 6 inches to a 4-foot tube, of a foot to an 8-foot tube, or of 2 feet to a i6-foot tube, will give the series a tone lower (in B flat), and a proportionate shortening of the C tubes will raise the series a tone (D) ; on the same basis, tubes which give any F as the fundamental of a series must be about midway in length between those which give the C above and the C below as fundamental. Examples: Trumpet (modern) in C-length about 4 feet ,, in F ,, ,, 6 ,, ,, (old) in C ,, ,, 8 ,, Horn in F ,, ,, 12 ,, ,, ,, C ,, ,, 16 ,, It will be noticed that the two lower octaves of the harmonic series are ve

Influence of Boethius on Troilus and Criseyde :: Troilus Criseyde Essays

Influence of Boethius on Troilus and Criseyde Around 524, the Christian philosopher Boethius awaited his death. During the last stage of his life, he composed one of the most influential writings of the Medieval period: The Consolation of Philosophy. C.S. Lewis says of the work, "To acquire a taste for it is almost to become naturalized in the Middle Ages" (Lewis 75). Over 800 years later, Geoffrey Chaucer, one of the most highly praised authors in the English language, would draw upon Boethius to compose his finest work, Troilus and Criseyde. The most important Boethian influence Chaucer extracts is the intensity of something being increased or decreased by the knowledge of its opposite. Boethius' main discussion of this concept is in books three and four deal where he deals with the problem of evil. The question at hand is, "How can evil exist in a world with an omnibenevolent and omnipotent God?" If God is all-powerful, is anything impossible for God? If God is all-good, can God commit evil? After much discussion, Boethius concludes that evil is a lack of good and those who commit evil lack something. He writes, "so it is plain that those who are capable of evil are capable of less" (Boethius 110). He continues, "Therefore the power of doing evil is no object of desire" (110). Thus "the power of doing evil" is a lack of "the power of doing good." Boethius can know what evil is only when he first realizes how to determine good. Chaucer states problem in this way: "Everything is known for what it is by its opposite"(Chaucer 14). Chaucer's main examples of this phenomenom deal with the sweetness of joy and the bitterness of suffering. First, sweetness is made sweeter when one has tasted the bitterness of suffering. "And now sweetness seems sweeter, because bitterness was experienced" (79). When one experiences extreme bitterness, the slightest fading of that suffering brings ecstasy. On the other hand, bitterness is all the more bitter when one has tasted the sweetness of delight. Pandarus says, "For of all fortune's keen adversities the worst kind of misfortune is this: for a man to have been in good times and to remember them when they're past" (86-87). If one has tasted a high degree of sweetness, a lower degree sweetness is not as satisfying. This line of thought seems to be directly from Boethius.