European Employment Policy Essay Example | Topics and Well Written Essays - 3000 words

European Employment Policy - Essay Example Therefore minimum wage laws have been introduced which foresee crisis of unemployment, if fewer employers are interested to hire labor, where as more people are willing to offer their services. Therefore, the law intends to maintain the equilibrium, to avoid social and economic turmoil. The amount of labor supplied by the workers is directly proportional to the nominal wage, a certain increase in the wage, forecast increase in the labor supply. The observation is based on the assumption that an employee hired at a low wage will prefer to consume 'leisure and forego wages', a slight increase in the nominal range, it becomes difficult to practice leisure and avoid labor, therefore there is an increase in the number of workers wiling to offer labor. The relationship between the labor supplied and nominal wage is function of different variables including price. A substantial increase in the price level will reduce the number of workers, at all wages (Wascher, 1995). The charter of European Union has observed that there exists an inverse relationship between the nominal wage, and the 'amount of labor demanded by the organizations'. A substantial increase in the wages is likely to compel the organizations to reduce recruitment schemes. The relationship has been derived on the basis of an assumption that the organization prefers saving for increased proportion of profitability i.e. such level of production is aimed by the organization which increases the profit i.e. the difference between expenses and revenue. The revenue is based on the price of an item, and quantity of the items sold (Christopher, 2005). The expenses include the amount of wages, which is based on the labor and services. Therefore, the company will prefer to maintain a minimum threshold level to secure profit, on the basis of reduction in the wages, as more workers are employed, the labor wage increases which turn the organization less profitable. The price factor may compel the organizations to recruit the employees for all wage levels (Gold, 1993). As per the regulation, the commission has defined a minimum age for the employment; the minimum age is greater than the minimum school leaving age. The charter has focused upon the fact that parent employees shall be provided parental leave, and parent employees have been urged to spend their time with their families particularly children. The charter has listed provisions for the access to childcare during working hours. The charter has defined a maximum limit for the weekly working hours; the maximum weekly working hours shall not be greater than forty eight, which is inclusive of the working hours. As per the charter, the employees are eligible for at least four week's paid annual leave, on unconditional basis. The charter has described minimum rest period which shall be eleven hours on daily basis, and minimum one day on weekly basis. The charter has limited the duration of work during might hours, and has limited the working hours during night time to maximum of eight hours (Gol d, 1993). Minimum Wages and Labor Market: Equilibrium It has been predicted that minimum wage laws are expected to increase unemployment, if minimum wage is established above equilibrium wage. It is because, a large number of employees will be interested in offering their services in exchange for higher wages, on contrary on small and limited number of such

Learning style Essay Example for Free

Learning style Essay There is no credible evidence that learning styles exist. While we will elaborate on this assertion, it is important to counteract the real harm that may be done by equivocating on the matter. In what follows, we will begin by defining â€Å"learning styles†; then we will address the claims made by those who believe that they exist, in the process acknowledging what we consider the valid claims of learning-styles theorists. But in separating the wheat from the pseudoscientific chaff in learning-styles theory, we will make clear that the wheat is contained in other educational approaches as well. A belief in learning styles is not necessary to incorporating useful knowledge about learning into ones teaching. We will then discuss the reasons why learning styles beliefs are so prevalent. Finally, we will offer suggestions about collegiate pedagogy, given that we have no evidence learning styles do not exist. What is a Learning Style? The claim at the center of learning-styles theory is this: Different students have different modes of learning, and their learning could be improved by matching ones teaching with that preferred learning mode. The way theorists have defined â€Å"modes of learning† has changed over the more than 50 years that this concept has been in vogue. Proposed modes have included dichotomies such as linear vs. holistic, impulsive vs. reflective, reasoning vs. insight, and visual vs. verbal. The most popular current conception of learning styles equates style with the preferred bodily sense through which one receives information, whether it be visual, auditory, or kinesthetic (for some reason, no one claims that there are tactile or olfactory learners). We use this sensory definition of learning styles in the examples below, but our conclusions apply equally to other definitions. As you will see, the claim that the mode of presentation should match the preferred mode of learning subsumes several other claims, and it is worth unpacking the learning-styles concept in order to consider its constituent subclaims separately. Which Claims of Learning-Styles Theorists are Correct? We believe that some general assertions of learning-styles proponents have nearly universal consensus, based on a wealth of evidence. We begin by acknowledging the truth of these claims in order to differentiate them from other ones without support. The first claim is this: Learners are different from each other, these differences affect their performance, and teachers should take these differences into account. This is true and recognized by educators and cognitive scientists alike. While many of those scientists seek to discover general principles of learning, we all acknowledge that there are differences among students. Understanding these differences and applying that understanding in the classroom can improve everyones education. We can find further agreement on some of the differences that matter for learning. First, whether we call it talent, ability, or intelligence, people vary in their capacity to learn different areas of content. One of the authors (Riener) has fraternal twin sons, and despite having most of the same experiences, one has learned to read earlier and the other is a better basketball player. This is clearly due to genetic differences in talent rather than a bizarre experiment in which the parents decided that one would be a basketball player and the other a professor. With educators under 6 feet tall for both parents and grandparents, they are both probably doomed to proceed to graduate school rather than to the NBA. Second, and often intertwined with ability, students differ in their interests. If a student loves the piano, or basketball, or chess, or the biology of frogs, that student will no doubt learn material related to that subject faster than another one who does not share that fascination. We all agree that interest and attention are preconditions of learning and vary from student to student, depending on the subject. Third, students differ in their background knowledge, and that difference influences their learning. This is obviously true in the sense that a large vocabulary allows one to read a wider variety of books. And it is further true in fields such as history: One cant hope to learn much about the causes and consequences of the American Civil War without knowing facts about the growth and separation of the colonies, the history of economic differences between the North and the South, political facts about our three branches of government, etc. But background knowledge is also quite important in things we think of as skills. For example, learning basic math facts is critical to the acquisition of later math skills. Finally, some students have specific learning disabilities, and these affect their learning in specific ways. For example, there is considerable research on dyslexia and the strategies for addressing it. These strategies of course differ from those appropriate for those students on the autistic spectrum or those with hearing difficulties. In each of these cases, a specific difference in the student calls for individual diagnosis and attention. So in claiming that learning styles do not exist, we are not saying that all learners are the same. Rather, we assert that a certain number of dimensions (ability, background knowledge, interest) vary from person to person and are known to affect learning. The emphasis on learning styles, we think, often comes at the cost of attention to these other important dimensions. What Do Learning-Styles Theorists Get Wrong? The next claim is that learners have preferences about how to learn that are independent of both ability and content and have meaningful implications for their learning. These preferences are not â€Å"better† or â€Å"faster,† according to learning-styles proponents, but merely â€Å"styles. † In other words, just as our social selves have personalities, so do our memories. Students do have preferences about how they learn. Many students will report preferring to study visually and others through an auditory channel. However, when these tendencies are put to the test under controlled conditions, they make no difference—learning is equivalent whether students learn in the preferred mode or not. A favorite mode of presentation (e. g. , visual, auditory, or kinesthetic) often reveals itself to be instead a preference for tasks for which one has high ability and at which one feels successful. But even if we did identify preferences that were independent of ability, finding ones that are independent of content is a much trickier proposition. If I were to tell you â€Å"I want to teach you something. Would you rather learn it by seeing a slideshow, reading it as text, hearing it as a podcast, or enacting it in a series of movements,† do you think you could answer without first asking what you were to learn—a dance, a piece of music, or an equation? While it may seem like a silly example, the claim of the learning styles approach is that one could make such a choice and improve ones learning through that choice, independent of content. We all agree that some kids show more interest in math, some start their education more interested in poetry, and others are more interested in dodgeball. The proof that the learning-styles theorist must find is that for some sort of content—whether it be math, poetry, or dodgeball—changing the mode of presentation to match the learning styles helps people learn. That evidence has simply not been found. Finally, we arrive at the critical and specific claim of learning-styles proponents: Learning could be improved by matching the mode of instruction to the preferred learning style of the student. Learning-styles believers do not make the claim that students sort neatly into sensory categories: One need not be purely visual, auditory or kinesthetic. But according to the theory, an educator should be able to improve the performance of those who have a strong preference for one of these sensory styles by matching instruction to their preference. Failure to find any experimental support for matching the mode of instruction to a preferred learning style would simply leave us where we were at the end of the section above: Students have different interests, backgrounds, and abilities. And indeed, a recent review article in the journal Psychological Science in the Public Interest by a group of distinguished memory researchers sought to find evidence for this claim in particular. If you are visual, you should learn better with a visual presentation of information than with an auditory one. If you are auditory, you should learn better with auditory materials than with visual ones. Each of this pair of results is necessary to support this element of learning-styles theory. But experiments that tested this prediction with a variety of content material have not found support for it. While such evidence of learning styles would serve as a proof that they exist, the lack of evidence does not prove definitively that they do not exist. However, in order to persuade us to devote the time and energy to adopt a certain kind of differentiated teaching, the burden of proof is on those who argue for the existence of that description of students cognitive strategies. In other words, a good rule of thumb is that we should only bring ideas from the laboratory into our teaching if (1) we are sure that the laboratory phenomena exist under at least some conditions and (2) we understand how to usefully apply these laboratory phenomena to instruction. The first of these two conditions is not met for learning styles, and the first is obviously a precondition for the second. Why Does the Belief in Learning Styles Persevere? What are the reasons for this myths perseverance? First, we think that a belief in learning styles persists because the more general claims (the ones we addressed above) are true. Learners do differ from one another. But many who believe in the myth do not consider the critical differences between styles and abilities. Teachers should take into account the differences in learners abilities. And adjusting a lesson not just to be appropriately pitched at the students level of ability but to take into account their background knowledge and interests is surely an important first step in fostering learning. Second, a belief in learning styles fits into an egalitarian view of education: Everyone has value, according to the theory, and everyone has strengths. The corollary for some learning-styles theorists is that if you think that the theory is wrong, you must think that all students are identical—which is obviously untrue. Again, we agree that students differ and all students have value, but we do not need learning-styles theory to convince us of that. Third, learning-styles theory has succeeded in becoming â€Å"common knowledge. † Its widespread acceptance serves as an unfortunately compelling reason to believe it. This is accompanied by a well-known cognitive phenomenon called the confirmation bias. When evaluating our own beliefs, we tend to seek out information that confirms our beliefs and ignore contrary information, even when we encounter it repeatedly. When we see someone who professes to be a visual learner excel at geography and an auditory learner excel at music, we do not seek out the information which would disprove our interpretation of these events (can the auditory learner learn geography through hearing it? Can the visual learner become better at music by seeing it? ) Why Should College Educators Care? We have addressed the direct costs of the learning-styles myth above, but there are considerable opportunity costs as well. The same research in cognitive science and education that has failed to find evidence for learning styles has offered many insights into how memory does work. Mindset (2006) by Stanford psychologist Carol Dweck is an excellent summary of the interesting ways that incentives—both carrots and sticks—as well as internal drives influence learning. And Henry L. Roediger and his associates at Washington University in St. Louis have demonstrated the value of testing for learning. Even the act of taking a test when one does not know the answers can support learning the correct answers faster and more effectively. Of course learning is an enormously complex activity, and this is not the place to outline all of the basic research on learning. We seek only to emphasize that attention to learning styles, for which evidence has not been found, may lead educators to neglect research on learning for which there is solid scientific support. Even though the belief in learning styles has influenced pedagogy in the schools far more than it has in higher education, we believe that there are several other reasons faculty might pay attention to the fact that researchers have failed to find evidence of learning styles, reasons that have important implications for the college classroom. First, when we poll our undergraduate classes on the belief in a number of myths of popular psychology, the one that â€Å"people have their own learning styles† is typically endorsed by more than 90 percent of our students. This belief has the potential to shape and constrain the experience that students have in the college classroom. For example, if a student believes she is a visual learner and therefore disengages and daydreams when a lecturer turns off the PowerPoint and tells a story, this will prevent her from learning the concept through a compelling narrative. And while these beliefs may not have as direct an impact on performance reviews as they do in K-12 settings, a belief in learning styles occasionally shows up in student evaluations of teaching: â€Å"I am a visual learner, so the visual examples were good,† or â€Å"I am an auditory learner, so more auditory content would have helped. † Second, learning-styles theory is sometimes offered as a reason to include digital media in the classroom. While including multimedia may be a good idea in general (variety in modes of presentation can hold students attention and interest, for example), it is not necessary to tailor your media to different learning styles. We shouldnt congratulate ourselves for showing a video to engage the visual learners or offering podcasts to the auditory learners. Rather, we should realize that the value of the video or audio will be determined by how it suits the content that we are asking students to learn and the background knowledge, interests, and abilities that they bring to it. Instead of asking whether we engaged the right sense (or learning mode), we should be asking, what did students think about while they were in class? Finally, when one has the opportunity in a smaller class to collect information about students and more specifically to tailor a lesson to that particular group of students, it is a waste of time to assess learning styles rather than, for instance, background knowledge. The latter can obviously be extremely useful. We often use prerequisites to ensure common background knowledge of students in a given class, but assessment at the beginning of a class can be an excellent reminder of how little of the prerequisite course content is easily recalled. Assessment of student interest can also be a useful tool for deciding how to approach the material in a given class. Some indication can be gained by what majors are represented in the class, but more specific interests assessed through a brief questionnaire or class discussion can also be useful in certain situations, such as small or homogeneous classes. So here is the punch line: Students differ in their abilities, interests, and background knowledge, but not in their learning styles. Students may have preferences about how to learn, but no evidence suggests that catering to those preferences will lead to better learning. As college educators, we should apply this to the classroom by continuing to present information in the most appropriate manner for our content and for the level of prior knowledge, ability, and interests of that particular set of students. Resources 1. Dweck, C. (2006) Mindset: The new psychology of success, Random House, New York, NY. 2. Paschler, H. , McDaniel, M. , Rohrer, D. and Bjork, R. (2010) Learning styles: Concepts and evidence. Psychological Science in the Public Interest 9, pp. 105-119. 3. Roediger, H. L. and Karpicke, J. D. (2006) The power of testing memory: Basic research and implications for educational practice. Perspectives on Psychological Science 1, pp. 181-210. Cedar Riener is an assistant professor of psychology at Randolph-Macon College. Daniel Willingham is a professor of psychology at the University of Virginia. He blogs at the Washington Post and is the author of Why Dont Students Like School? (Jossey-Bass, 2009). Related Notes Change Magazine September-October 2010The Myth of Learning Styles by Cedar Riener and Daniel Willingham There is no credible evidence that learning styles exist. While we will elaborate on this assertion, it is important to counteract the Learning with es: A convenient untruthThursday, 24 November 2011 A convenient untruth What do you think is the teachers worst enemy? Some would say lack of time. Others would say unsupportive leadership, or the dreaded government inspect

Stress And Well Being Psychology Essay

Stress And Well Being Psychology Essay People act in different ways in stressful situations, some can cope with stressful situation and some cannot cope. People are more stressed today than in the past. Researches were made to measure and to manage stress. For measuring stress, researches used a couple of types. One was the Social Readjustment rating scale or SRRS. This measure of stress was devised by Holmes and Rahe in 1960. Their thought was that stress is more about the need of readjustment and change. For their research, they gathered almost 400 Americans and listed a scale of life events that could affect an individual. In their opinion, life changes have a major impact on an individual. In this scale at the top was death of a spouse with 100 units of life changes and the rest were adjusted accordingly. Almost 300 or even more of life changes units were linked to higher psychological and physical illnesses. Applying this method to measure stress, leads to some weakness and strengths, in which, the strength will be that it does capture something about stress, as SRRS were proven to be related to illnesses. A weakness could be that a particular life event like an operation for a person who has a life threatening illness is more str essful than a person operation for esthetical enhancement who just want to change something.(handouts, 12.11.2012) Questionnaires measures is another type of stress measuring like SRRS, the Type A personality, Hassles and Uplifts, etc. With questionnaire method is more easy to measure stress because they are quick and easy to administrate, but the weakness is that people may not be sincere when they answer. Some people could give answers in a way that will make them look good (social desirability bias). There are also job strain questionnaire based on job demands. Workers facing high psychological workloads demands and pressure, who work very fast, very hard and do not have enough time to finish their job, are in a greater risk for mental and physical illness.(handouts, 12.11.2012) Another type of stress measuring is controlled observation. There are various ways to measure, some of them cruel for example electric shocks, overcrowding, extremes of heat and colds used as stressors and others methods, by permanent interrupting the subjects during tests. A lot of researches were made on a link between Type A personality and heart diseases. The ones who developed the idea of Type A personality were Friedman and Rosenman. They had a different style to measure this Type A. They were given tests to people and then they constantly interrupt them during testing. They could observe that some of the participants dealt well with interruptions but some were more stressed because of the constant interruptions.(handouts, 12.11.2012) While measuring stress, researchers came up with some methods of stress management. They grouped up this stress management methods in two, one psychological method in which are hardiness training and stress inoculation training and the other is the physiological method containing drugs and biofeedback techniques. (Gross, R., psychology, 5th edition, 2005) Suzanne Kobasas Hardiness Training has the three major Cs: Control, Commitment and Challenge. The people with hardiness personality are more in control of their lives, they can manage better stressful situation and see difficulties as a challenge rather than a problem. Thats why Hardy personality is stress-resistant. The training for this has three stages. The first one is focusing, in which the client is thought to be able to recognise the biological signs of stress such as increase of heart rate, muscle tension and also to be able to identify the source for this stress. The second stage consists in reliving stress encounters, in which the clients relive their stress encounters and are helped in analysing those situations and their response to them. This method could give them some insight on coping strategies. The last one, self-improvement, involves learning of new techniques for the increase of the three Cs.(psychology AS, 2012/handout, 22.10.2012) Stress Inoculation Training or SIT is aiming to change peoples behaviour and thinking and is a cognitive behavioural therapy being specifically developed to deal with stress. There are also three stages as in Hardiness. The first stage is Conceptualisation phase, in which a relation is established between client and the therapist and the client is educated about the impact and nature of stress. The client is trained to be able to identify the stressors and to learn how to breaks them down into chunks that can be tackled. The second phase is Skills acquisition. Here the person will develop skills in constructive thinking. First the skills are taught and practised in the clinic and after that they can be gradually rehearsed in real life. The skills can include positive thinking, relaxation, social skills, etc. The last phase Application and follow-through, in which clients are given opportunities to apply in real life the coping skills learned, some could be ask to even train others as well.(psychology AS, 2012/handout, 22.10.2012) The Hardiness Training and the Stress Inoculation Training are both psychological methods. The next method is physiological which consist in Drugs intake as a method of stress management. There are a lot various types of tranquiliser and anti-anxiety drugs. The most common are benzodiazepines or Bz shortened. These include Librium, Ativan and Valium. The effect of this drugs is to lower the level of serotonin activity in the brain. If the level of serotonin is too low, produce depression but if it is too high produce anxiety. In 1960 they were highly prescribed as a replacement for barbiturates. Another group of tranquiliser are beta-blockers. Their activity is that of reducing the activation of the sympathetic branch of the anatomic nervous system meaning the activity reduction of SAM axis. The drugs are fast effective but the problem is that they are highly addictive.(handout, 29.10.2012) Based on the evaluations of the methods, there can be found a lot of weaknesses and strengths in each and every one of them as well as similarities and differences between them. In Hardiness Training strengths are that is it working, it deals with the cause of stress not just the symptoms, are more effective to people. The weaknesses consists in focusing on middle-class business people, some people find control stressful-they dont like to be in control, people respond in different ways to Hardiness Training, some people doubt about the all three Cs being equally important in protection against stress and even though control is important the commitment and challenges have no effects. (hand out, 22.10.2012 / psychology AS, 2012) SIT works well in general and also works for acute and conic stress. The weaknesses of SIT consists in it being time consuming, requiring high motivation and in the fact that not all people need the same skills to cope with stress. (hand out, 22.10. 2012 / psychology AS, 2012) Drugs work in reducing anxiety also BZ are better than placebo effect, drugs are easy to use involving only the need to actually take the pill and for some forms of phobias are quite handy. Weaknesses are the fact that some drugs are highly addictive, produce strong withdrawal symptoms, patients develop tolerance to them quickly, effectiveness requires a higher dosage, they have a limit of recommended intakes of a maximum of four weeks, treats the symptoms not the actual cause of stress, does not sort out the problem and because of dependency of drugs some people become like vegetables. ( hand out, 29.10. 2012 / psychology AS, 2012) The similarities between these types are: all of the methods allows the person to be in a better frame of mind to deal with stress; both SIT and Hardiness Training involves motivation and they take place over weeks and treat the cause rather than the symptoms and both change the way people think and help people learn skills to deal with their stress. The differences between these types are: The effects of the drugs are relatively instant while the effects of SIT and HT require a longer period of time and greater effort until the results are seen; Drugs can be addictive and have short term solutions but other methods like HT may deal with the real issue; people can develop tolerance to drugs in comparison with the other methods that are more constant; drugs have side effects, the other methods dont; no withdrawal effect from stopping SIT and HT like there is with drugs; HT depends on the liking for control but drugs dont.

Philosophy Essay -- Socrates

There are three different parts of elements in one’s soul called: Reason, physical appetites and spirit due to the inner conflict. Each part of the soul is doing its own job. A man can have two different responses from his inner world when he has a conflict to decide. For example, a man was thirsty. He wants to drink some water because his appetite is telling him that he needs to quench. While his reason part will list out all the rational reasons for avoiding him from drinking, such as the water can make you sick. When the man’s desire was higher than reason then the sprite will appear to support with appetite (138). However there is another situation when the spirit will help reason out. â€Å"When the soul is divided into factions, it is far more ready to be up in arms on the side of reason† (138). Reason can consider as wisdom because it is the leader of the soul. It gives rational orders for spirit to follow, so they could work together to hold the appetite s. Then spirit can symbolize courage because the spirit is not afraid of against enemies in order to carry out its mission for holding the appetites in all circumstances because appetite is like the many-headed of the monster as it mentions in Chapter XXXIV. The many-headed symbolized the divided mind of the monster. It needs the lion to help the man to control the many-headed monster since the power of the man will be weak when there are many desires of the monster. Hence, the man symbolized the reason and the lion symbolized the spirit. Moreover, there shouldn’t be any internal conflict between these three since they are all doing a great job. This phenomenon of performing good cooperation is called temperance. According to Socrates â€Å"the reason for all this is that each part ... ... careful since once people had chosen for the character they want to be such as be an animal or human being, and then it’s their duty to be responsible for their decision. At the end of the story it tells the part when people pass through the River of Unmindfulness. That all the people â€Å"Required to drink a certain measure of this water, and some have not the wisdom to save them from drinking more. Every man as he drinks forgets everything† (359). Which means if a person drinks too much water then he will not remember that there always has penalty for being unjust, thus his moral will not going to be increased because he will keep doing unjust thing and thinks there is no punish for it. In conclusion because of immortality, people understand the concept of being unjust need to bear the punishment, which helps a person, can have better moral understanding. Philosophy Essay -- Socrates There are three different parts of elements in one’s soul called: Reason, physical appetites and spirit due to the inner conflict. Each part of the soul is doing its own job. A man can have two different responses from his inner world when he has a conflict to decide. For example, a man was thirsty. He wants to drink some water because his appetite is telling him that he needs to quench. While his reason part will list out all the rational reasons for avoiding him from drinking, such as the water can make you sick. When the man’s desire was higher than reason then the sprite will appear to support with appetite (138). However there is another situation when the spirit will help reason out. â€Å"When the soul is divided into factions, it is far more ready to be up in arms on the side of reason† (138). Reason can consider as wisdom because it is the leader of the soul. It gives rational orders for spirit to follow, so they could work together to hold the appetite s. Then spirit can symbolize courage because the spirit is not afraid of against enemies in order to carry out its mission for holding the appetites in all circumstances because appetite is like the many-headed of the monster as it mentions in Chapter XXXIV. The many-headed symbolized the divided mind of the monster. It needs the lion to help the man to control the many-headed monster since the power of the man will be weak when there are many desires of the monster. Hence, the man symbolized the reason and the lion symbolized the spirit. Moreover, there shouldn’t be any internal conflict between these three since they are all doing a great job. This phenomenon of performing good cooperation is called temperance. According to Socrates â€Å"the reason for all this is that each part ... ... careful since once people had chosen for the character they want to be such as be an animal or human being, and then it’s their duty to be responsible for their decision. At the end of the story it tells the part when people pass through the River of Unmindfulness. That all the people â€Å"Required to drink a certain measure of this water, and some have not the wisdom to save them from drinking more. Every man as he drinks forgets everything† (359). Which means if a person drinks too much water then he will not remember that there always has penalty for being unjust, thus his moral will not going to be increased because he will keep doing unjust thing and thinks there is no punish for it. In conclusion because of immortality, people understand the concept of being unjust need to bear the punishment, which helps a person, can have better moral understanding.

Polyester Manufacturing

Polyester fibers, the synthetic fibers, are long chain polymers derived from coal, air, water, and petroleum. They are formed through chemical reaction between an acid and alcohol. In this reaction, two or more molecules combine to make a large molecule whose structure repeats throughout its length. These molecules are very stable and strong. There are variations in the compositions and therefore in the properties of polyester fibers. Types of Polyester The polyester fibers are generally available in two varieties- PET (polyethylene terephthalate) and PCDT (poly-1, 4-cyclohexylene-dimethylene terephthalate). PET is the most common production. It is stronger than PCDT, while PCDT has more elasticity and resilience. PET can be used alone or blended with other fabrics for making wrinkle free and stain resistant clothing that can retain its shape. PCDT is more suitable for heavier applications, such as draperies and furniture coverings. Modifications can be introduced in each of these varieties for obtaining specific properties. PET Polyester For manufacturing PET Polyester, the main raw material is ethylene derived from petroleum. It is oxidized to produce a glycol monomer dihydric alcohol which is further combined with another monomer, terephthalic acid at a high temperature in a vacuum. Polymerization, the chemical process that produces the finished polyester, is done with the help of catalysts. The colorless molten polyester then flows from a slot in a vessel on to a casting wheel and takes shape of a ribbon as it cools to hardness. The polymer thus produced is then cut into very small chips, dried to remove all moisture and blended to make it uniform for getting it ready for spinning into yarn. PCDT Polyester This variation of polyester is made by condensing terephthalic acid with 1, 4-cyclohexane-dimethanol to form poly-1, 4-cyclohexylene-dimethylene terephthalate or the PCDT Polyester. As for PET Polyester, PCDT is processed for melt spinning. Spinning Polymer chips are melted at 500-518Â °F (260-270Â °C) to form a syrup-like solution. The molten polymer is then extruded through a spinneret and the filaments are subsequently drawn into the desired polyester fiber. Variations are introduced to obtain desired end results. Spinnerets having hole of different shapes such as round, trilobal, pentalobal, hexalobal or octalobal can be used for special effects like opacity, luster or its suppression, wicking, comfort or feel. Hollow fibers may be produced to make it lightweight and for providing greater cushioning or insulative properties. Crepe effect can be obtained through crimps. Certain additives may also be combined with the spinning solutions for specific properties. Delusterant can be added to make the fiber dull, a flame retardant may be added or Certain other antistatic substance may also be included. Drawing After extrusion from the spinneret, the fibers are drawn or elongated, with the help of godet wheels. Depending upon the desired properties, the polyester fibers are usually drawn up to five times its original length. For higher tenacity, the filaments are drawn to a greater extent. When the fibers come in contact with the air, they solidify. Usually, the PET fibers are drawn hot as it produces more uniform fibers. PCDT fibers are drawn at higher temperature due to their higher melting point. During the drawing process itself, fibers may be textured which saves time, efforts and production cost and also gives greater quality control over the finished fibers. After the polyester yarn is drawn, it is wound on large bobbins or flat-wound packages, ready to be woven into material. Types of Polyester Yarns The polyester yarns have a wide range of diameters and staple lengths. The yarns are made basically as monofilament yarns, multifilament yarns and spun yarns. Filament Yarns PET Polyester is used to make filament yarns either in monofilament or multifilament forms. The direction and amount of twists are decided by the desired end use. The properties are also pre-determined. There are various types of such yarns. There is the bright, regular tenacity polyester yarn having light, stretch and sag resistance, used for sheer lightweight fabrics like tulle, voile and organdy. The regular tenacity semi dull yarn used for various apparels including lingerie. Its more dull version is used for shirts and blouses. Polyester yarns resistant to various chemicals, and microorganisms are produced from high tenacity fibers for such industrial uses as conveyor belts, ropes and nets etc. Textured Yarns These yarns are made of PET multifilament’s. Texturizing is either done along with the drawing process or afterwards during throwing or texturizing process. Spun Yarns They are made of staple or cut PET or PCDT polyester fibers. The staple may be bright, semi dull or dull and tenacity may be regular, mid or high. It may be polished to reduce crimp and increase luster. It may either be spun alone or blended with other staple such as cotton, wool or rayon and then spun into yarn. Application of Polyester Polyester is used in manufacturing of many products, such as clothing, home furnishings, industrial fabrics, computer, recording tapes, and electrical insulation. It has several advantages over traditional fabrics as it does not absorb moisture. Its low absorbency also makes it naturally resistant to stains. Polyester clothing can be preshrunk in the finishing process. This makes it resist shrinking and it doesn't stretch out of shape. The fabric can be dyed easily, and is mildew resistant too. Textured polyester fibers are an effective, nonallergenic insulator, thus it is used for filling pillows, quilting, outerwear, and sleeping bags.

Center Around and Centre Round

Center Around and Centre Round Center Around and Centre Round Center Around and Centre Round By Maeve Maddox The phrases â€Å"center around† (US) and â€Å"centre round† (Br) are often heard in speech and seen in writing on the Web: Other concerns centered around decreased property values.- Book published by SUNY Press, 2004. Our concerns center around response time to our emergency rooms.- Statement issued by a Florida medical center. The main  issues centre round  the high level of ambient noise in the area.- Canadian newspaper. These concerns centre round the following issues:- Trinity College, Dublin. These proposals centre round the proposition that core labour standards should be incorporated into a â€Å"social clause† in international trade agreements.- Australian source. The economic crisis gives rise to its own particular claims, specifically those brought by lenders against solicitors and valuers, which tend to centre round the professional’s alleged failure to report information which would have affected the decision to lend.- UK law journal. British and American style guides generally advise against this usage on the grounds that it is illogical. The preferred prepositions to use with the verb center/centre are on and in. The objection to â€Å"center around† is that something centered is fixed in a certain place. Therefore, it cannot move around something else. Concerns may â€Å"revolve around issues,† but they cannot â€Å"center around† them. The edition of Fowler’s Modern English Usage published in 1924 does not mention this idiom, but the Second Edition, published in 1965 and revised by Sir Ernest Gowers, calls attention to it. Admitting that idioms are not required to be logical, the editor nevertheless rejects â€Å"centre round† because â€Å"centre in† or â€Å"centre on† are logical, and â€Å"centre round† is not: There is nothing to be said for preferring the illogical centre round, as though centre and gather were synonymous. As a noun centre has its own precise meaning and should not be used as a genteelism for middle. The Penguin Writer’s Manual (2002) points out that, logically, the verb centre should be â€Å"followed by the prepositions at, in, on, or upon.† However, it also notes that â€Å"the phrase centre around or round is well established and has been used by many respected writers such as Conrad and Kipling.† The Chicago Manual of Style weighs in against â€Å"center around† in its â€Å"Good usage versus common usage† section: Although this illogical phrasing does have apologists, careful writers tend to use either center on or revolve around. Professor Brians (Common Errors in English Usage) has nothing mitigating to say in its defense: Two perfectly good expressions- â€Å"center on† and â€Å"revolve around†- get conflated in this nonsensical neologism. When a speaker says his address will â€Å"center around the topic of† whatever, my interest level plummets. Want to improve your English in five minutes a day? Get a subscription and start receiving our writing tips and exercises daily! Keep learning! Browse the Expressions category, check our popular posts, or choose a related post below:10 Grammar Mistakes You Should AvoidCannot or Can Not?How to Style Legislative Terms