Polyethene Essays - Commodity Chemicals, Packaging Materials

Polyethene Polyethylene also known as polyethylene or polythene, was the first of the polymers to be discovered. Polyethene is a polymer produced by reacting oxygen and ethene, in this reaction the small ethene molecules attach together to form long chain polymer molecules. This process is known as addition polymerisation. Polyethene in our world today has many uses, some of these are: ? mouldings-plastic bottles, lids and caps, different types of containers. ? films-glad wrap and various plastic bags. ? cable coverings-various pipes and insulating wire and cables As you can see polyethene has a huge variety of both domestic and industrial uses, this is fairly impressive when you see that polyethene has only been around sense 1933. Polyethene is a thermoplastic material which is often described as wax-like it is extremely tough and is has an excellent chemical resistance. It is also less dense than water and is the simplest polymer, these attributes lead to polythene being an extremely useful substance. Ethene (C2H4), is a simple hydrocarbon molecule which consists of 2 carbon atoms and 4 hydrogen atoms. Ethene's main use is in the production of polythene yet it is one of the most widely used petrochemicals in the world. Ethene is an unsaturated colourless gas which can be ignited in the presence of oxygen. Below is a diagram of ethene: Polyethene is produced by allowing the free roaming ethene gas molecules to bond together to form long chain polyethene molecules. In order for this to work a catalyst must be used, a catalyst is a substance that can alter the rate of a chemical reaction without undergoing any chemical change itself. During this process thousands of ethene molecules bond to from each molecule of polyethene. Polyethene is simply a set of ethene molecules bonded together to form a chain, these chains can often stretch up to many many times longer than the original ethene molecule. Below is a diagram of polyethene: Although normally ethene monomers have little attraction for one another, yet the polyethene molecules have a strong attraction for one another. When polyethene molecules are attracted and bond high-density polyethene is formed, thus polyethene is either formed by low-density or high-density polymerisation. Ethene can undergo the process called polymerisation due to the fact that it is unsaturated and because it has a double bond between its two carbon atoms. Both High-density and low-density polyethene have different uses. Low-density polyethene is used in the production of products such as various bags, plastic bottles, cling wraps, and insulating cables. Low pressure polymerisation with the use of certain catalysts; has meant that the process of polymerization can be achieved at fairly low pressure (20 atmospheres or 2000 kPa) and at temperatures of approximately 100?C. The reactor itself contains a polyethene bed placed on a perforated plate. It works by allowing the recycled gas to enter near its base, the gas then passes through the plate and pushes up through the bed causing it to bubble. Finally the catalyst converts the ethene to polyethene, once the polyethene is cooled it forms a fine powder called 'fluff' which is then collected and transported to a storage bin. Any ethene gas which has not reacted passes through a compressor and then a cooler, and is processed again. High-density polyethene is used to produce items such as lids, caps, baskets, bowls and large containers such as garbage bins. These polyethene products are created in what is know as high-pressure polymerisation, this is a process that was originally used before low-pressure polymerisation was discovered and thus it is a fairly simple process. Firstly Ethene gas is compressed and liquefied, from here it is pumped into a large reactor at a pressure of up to 2660 atmospheres(266 Mpa). Amongst this oxygen and peroxides are pumped in to initiate the polymerisation reaction. This process generates a huge amount of heat so the most complex part of the system is the cooling facilities. The many products of polyethene which are most commonly used are generally manufactured using any of these five different techniques Extrusion - film, this technique is used for the production of items such as plastic bags such as garbage bags and glad wrap. These are the most common applications, while there are many others these are the best examples of this technique. This final product is achieved by blowing air into a tube of molten plastic this allows for extremely fine layers of the plastic to form. Blow moulding, this is used to make plastic bottles and some motor oils. This technique is much like the previous

Asprin essays

Asprin essays The discovery of aspirin dates back to the 5th century B.C., when Hippocrates used a powder from the bark of a willow tree to ease minor pains, reduce fevers and to help with childbirth. The willow tree powder was actually salicin, the pharmacological ancestor to the family of drugs known as salicylates. The best known of which is aspirin. Later efforts where made to neutralize salicin with sodium, but unfortunately turned out to be useless. In 1853 a French chemist named Charles Fredric Gerhardt tried to improve sodium salicylate in 1853. He combined it with acetyl chloride, which proved to be less irritating to the stomach. After a few years of hard work, Gerhardt didnt see any future with this concoction and soon abandoned it. In 1899 a German chemist, Felix Hoffmann set out to find a formulation to relieve his fathers arthritis pain. Hoffman used Gerhardts research to synthesize acetylsalicylic acid (ASA), a compound that appeared to lower fever, reduce pain and at high doses relieved arthritis. Hoffmann, who worked for Bayer, took his research to his superiors. They, however, doubted the commercial success of ASA. This was because ASA commonly caused shortness of breath and very high heart rates when taken in large doses. Fredrick Bayer in is the common drug ending of that time. When Bayer marketed the drug in 1897, they had no idea that it would turn out to be the most commonly used pain reliever in history. Aspirin works by inhibiting the production of prostaglandins, which are hormone-like substances that influence the elasticity of blood vessels, control urine contractions, and the direct functioning of blood platelets. Blood platelets cause blood clots and regulate numerous body functions. John Vane, Ph....

Using Cell Phones While Driving Term Paper Example | Topics and Well Written Essays - 2250 words

Using Cell Phones While Driving - Term Paper Example According to the same survey (Britt, 2005), those driving and talking on cell phones responded slower to brake lights by an average of 18% and 17% took a longer time to regain speed after braking for a light. It has also been noted that the hands free cell phones cause the same, slower responses among those that are driving and don’t lead to safe roads that can be driven on (Britt, 2005). The problem with using a cell phone while driving is now not only applicable to talking to others while on the road. Text messages, adding in music and the distractions from the cell phone are all adding into problems that are associated with those who are driving on the road and that are multi-tasking while driving. To change this, there are new laws that are trying to be passed, specifically because of the adverse effects which this has. However, the laws and the regulations by officials have not changed the number of individuals that use a cell phone on the road for any purpose, leading to more danger to those that are on the road and continuing to lead to accidents because of the lack of bans that are reinforced by officials (GHSA, 2011). Relationship of Cause and Effect The cause of using cell phones while driving is considered because of the association with needing to talk to others, communicate or update individuals while on the road. ... The use of cell phones on the road is one which may be more applicable while waiting at a stop light, going through slower traffic or driving through roads which are already known to those that are driving (Strayer, 2001). The cause of using cell phones while driving among the age group of 20-30, which is known as more likely to use phones while driving, is most likely specific to the need to communicate with friends, family or the work that one is involved in. The hectic lives that most lead at this age make the driving time the easiest to catch up with the communication that is needed. The knowledge of the road and the ability to multi-task while driving is one of the ways that most in this age group are trained, specifically with the understanding that doing more than one thing at a time is acceptable. The rise in technology has led to the behavior of multi-tasking and makes the cell phone use while driving natural. Even though there may be a natural tendency to use cell phones wh ile driving because of the multitasking which takes place, there are also other variables which are considered with this. The effects which occur lead to being over stimulated in specific conditions. If one is driving on a road that doesn’t have as much traffic or which doesn’t require as much attention, then the cell phone speaking may seem applicable. However, extra stimulations and interference from other coming traffic, changes in the road and the consequences of paying more attention to the phone than the road lead to the crashes and injuries that have been reported. The effect is from the stimulation that occurs which doesn’t allow one to respond quickly enough when speaking on a cell phone, showing that the

Domestic violence Research Paper Example | Topics and Well Written Essays - 1250 words

Domestic violence - Research Paper Example Owing to its legality, alcohol is a ubiquitous in many societies around the world and many individuals engage in alcohol consumption. In North America alcohol can be found in liquor stores, neighborhood convenience stores, grocery stores as well as in your local bar. Although alcohol is prevalent and easily accessible, it remains a harmful drug with the potential to kill, ruin lives and destroy families. Accordingly, one of the most insidious aspects of alcohol is that it is so freely available that we forget that it is a harmful drug with important health ramifications as well as a many important social consequences for individuals who choose to over indulge in alcohol. Alcohol-related fatalities remain an important concern across the globe and despite its ubiquitousness, alcohol abuse has been proven to lead to conflict and violence.2 Seeking to address the relationship between alcohol abuse and domestic violence, the following will, discuss alcoholism and provide a broad conceptual framework for our analysis. We then turn to a discussion of the dynamics of different types of alcohol-related conflicts, including the role that alcohol plays in perpetuating conflict with the family unit, with a spouse and with children Following this thorough discussion of the different dynamics and types of conflict caused by alcoholism, we turn to an in-depth discussion of the particular approaches used to deal with conflict. In this section we will explore the use of mediation as a method to deal with alcohol-related conflict. We will discuss groups such as Alcoholic’s Anonymous (â€Å"AA†) and the role that group mediation can play in resolving conflicts which have been brought on by alcohol abuse. We then turn to an analysis of family/group counseling and a discussion of the role of intervention in combating alco hol-related conflicts. With the goal of providing a holistic analysis to a complicated – yet increasingly

K to 12 in the Philippines Essay Example for Free

K to 12 in the Philippines Essay The Department of Education’s mission speaks clearly of the provision of a quality basic education that should be accessible to all and one which shall lay the foundation of a lifelong learning and self-actualization needed for citizenship at the local, national and global milieu. This mission can only be realized if indeed our educational system meets the challenge of the new millennium. Currently, educators just realized that our educational system has not been updated as to meeting the global competitiveness. It must be an acceptable fact that we have produced graduates who lack the skills, who cannot be recognized globally, and who do not possess entrepreneurial skills or the basic knowledge for higher education. I personally believe that it is high time that we start changing the educational system of the Philippines through the implementation of the K to 12 Basic Education Program. As a secondary school teacher, I have witnessed personally how our young generation graduates without having themselves equipped totally the basic knowledge they must have developed in the previous curriculum implemented in the schools. According to a survey, it is only the Philippines which has not adopted the 12 years basic education program in the whole of the Asia. This is the very reason why even if we have intelligent and globally competitive graduates, these graduates cannot still be recognized as professionals abroad because they lack the number of years to complete the basic education. Its implementation is actually a bold and a great challenge to curriculum developers and implementers (teachers) in our country. There are several problems that we have to overcome. But with everyone looking at one vision, holding hand in hand towards its successful implementation, lifting up each of our spirits – then the K to 12 implementation will have a successful journey. TERESA E. INDAC MAED-CMUGS

Psychoanalytic Approaches to Personality :: Psychoanalysis Psychology Freud essays

The area of psychology with perhaps the most controversial history, due to it’s complete lacking of empirical evidence, psychoanalysis, has it’s origins in the teachings of Sigmund Freud. Psychoanalysis is a form of therapy developed by Freud in the early 1900’s, involving intense examinations into one’s childhood, thought to be the origins of most psychopathology which surfaced during adulthood. Ideas about the subconscious, which saw the human mind as being in continuous internal conflict with itself, and theories that all actions are symbolic, for â€Å"there are no accidents†, were also major themes of the psychoanalytic approach. Successful therapy was a long-term and costly process, which most people during that time, with the exception of the wealthy, could not afford. Sigmund Freud’s main contribution to this new field of studying personality was in the area of the understanding the unconscious, an aspect of the mind to which, he claimed, we did not have ready access to, but was the source of our actions and behavior. Freud believed the human mind was divided into three parts: the id, ego, and super-ego. The id is man’s (generic meaning, referring to both sexes) instinctual, primitive, and hedonistic urges for pure pleasure, which the id was bent on experiencing, without regard to any consequences. The super-ego is man’s senses of morality, first brought on by experiences with authoritative figures and parents, which basically hold ideas of what is right and wrong, and is almost a direct paradox to the id. The ego, which can be seen as the mediator between the id and the super-ego, takes into account the activities of the external world, and attempts to invoke some balance among all three parts of the mind, with failure resulting in neurosis of some kind. Freud’s â€Å"Lecture III† provides, what I believe to be another important theory in understanding personality from this perspective, stemming from his notion of parapraxes, or unintentional acts that are actually unconsciously intentional. Such is the case with the familiar â€Å"Freudian slip†, where something is said which is actually a distortion or paradox of what is actually meant. This goes along with what are called symbolic acts, which are actions we take that, although we insist they have no meaning, or were accidental in nature, are actually intentional. For example, the act of forgetting is, according to Freud, a kind of intentional defense mechanism, that we unconsciously use to repress memories, or put things out of our minds. Although much of Freud’s work has been highly criticized by many of his detractors, there are certain aspects of his theories which I find quite important to the study of

Negative Classroom Behaviors Essay

In the classroom there are many opportunities for disruptions to the flow of learning. When the process of education is disrupted it affects learning outcomes and student progress. Educators and students both play a vital role is how smoothly the class is run. In this paper we will examine common disruptions in the classroom and look at carious ways that these disruptions can be resolved productively and efficiently. Through incorporating different discipline and classroom management styles most interruptions to learning can be avoided and the process of education can continue. Disruptions come in many forms and we will look at a few. We will first look at common disruptions in the classroom caused by students and then take a look at those caused by teachers. Yes teachers can be a disruption to the learning process and as we will see sometimes they cause more disruption than their students. It seems that often in today’s society when we think of the typical public school classroom, images of chaotic behavior, chattering students and paper being thrown quickly come to mind. This behavior, while not uncommon should not be the norm, there is a solution. The first three behaviors that we will address is the seemingly ever-present excessive talking, laughter and general outburst. It seems that no matter how many times the lights are turned off, names of students are written on the board, recess or free time taken away students continue to use their voices out of turn in excess ways, making instruction and learning difficult. Often times when students have an outburst in the class or the talking becomes excessive, teachers sometimes give a general knee-jerk reaction.  They may yell at the student who has been consistently talking to â€Å"be quiet or†¦ then some threat of a punishment is given and the student is quiet for a moment and the behavior is likely to happen again and the process continues. Educator Barbara Coloroso believed that students should be taught how to govern themselves accordingly and that whatever actions took place in the classroom they were not only responsible for them but that they were held accountable for them. Barbara guided educators to understand that an important part of education students was to also teach them inner discipline and self control. (Building Classroom Discipline, 11th edition, 2014) In her book Kids Are Worth It: Giving Your Child the Gift of Inner Discipline, Coloroso outlines key ways in which not only parents but also educators can teach children how to have inner discipline. Coloroso suggest that inner discipline be developed as follows; First students must be shown what they have done wrong, then given ownership of the problem hence making them responsible, following this students are guided on ways to solve the problem when appropriate. Finally Coloroso encourages to educators to ensure that during this entire process the dignity of the student is kept in tact. I imagine that by incorporating this strategy into my classroom management and discipline style my students will gain more self-control and become more aware of the consequences behind their actions. In this way, they will be far more likely to think before they act. Likewise I as a teacher will feel better about the way in which I handle disruptions. With the ability to handle each disruption as a possible teaching moment that encourages students to do better, rather than simply pointing out what they did wrong, students will develop a better sense of trust. Likewise by ensuring that in each situation the student is treated with dignity, students are aware of the respect I have for them and this respect become reciprocal. Two other common disruptions in the classroom are that of students who get out of their seats at inappropriate times and who take a long time to get organized, settle down and get started on their work . This not only disrupts learning for the student who gets up but it causes a distraction for those around. Often there are tedious reasons for why students are not in their seats. When asked why have they gotten up, a student may respond  Ã¢â‚¬Å"I was going to sharpen my pencil.† Likewise when asked why have they not sat down and began the warm up they may reply â€Å"I cannot find my pencil.† Educators Harry and Rosemary Wong created a classroom management and discipline theory that creates a way to eliminate many classroom disruptions. The Wong’s theory suggest, that beginning with the first day of class, students be taught that not only the classroom but that the entire school was a place for successful learning. This theory had to be accepted school wide in order to work effectively. In order to achieve that success teachers, students and administrators and support staff, must do their part. The Wong’s suggest that the biggest hindrance to learning is not the behavior of the students but the ineffective manner in which teachers disseminate information regarding the roles, rules, procedures and expectations in the classroom. (Building Classroom Discipline, 11th edition, 2014) Upon introduction to the class, teachers are encouraged to two things. First teachers must go over the roles, expectations and responsibilities of both teacher and student (Building Classroom Discipline, 11th edition, 2014). This is done over a period of several days and may continue through reinforcement throughout the first portion of the school year. In this way students not only understand where they fit in the classroom but they also know how everyone else fits as well. In my own classroom I can visualize my students on their first day. Part of my classroom management style will be to ensure that there is a procedure set in place for most of the foreseeable situations in the classroom. One thing that I will make certain to do, is to make the procedures detailed yet simple to understand and follow. In this way my students will be clear on what to do and when. For example, the student who has wasted ten five minutes of the 15 minute warm up time, will know in the beginning of the school year that sitting down and getting started on the warm-up up within the first three minutes of class is mandatory. If you are not prepared and do not have all of your materials, there are always extras that can be checked out from me and then returned at the end of class. Simple procedures like this will eliminate small disruptions and keep the learning process flowing. The next two disruptions are those students who lack respect for teachers and fellow  classmates along with horseplay in the classroom. Teachers must establish and demand respect in the beginning of the class. Students must know not only what is expected of them, but also what happens when they fall short of those expectations. Educator Craig Seganti teaches teachers how to take charge in the classroom. Taking the Seganti approach in my class will dictate that my students know that I am the authority in the classroom. Establishing this authority by setting the rules along with the consequences of breaking them, and enforcing them from day one will put me in control from the outset. When students see that there is no wavering in the rules, they will take what you are saying seriously. Establishing that the classroom is a place of learning and that anything that disrupts that will have consequences will if not completely eliminate, will certainly minimize disruptions. When teachers and students are disrespected in the classroom it would be good to incorporate civility in the classroom. P.M. Forni was best known for teaching students how to behave civil and with respect n the classroom. By encouraging students to conduct themselves in a way that reflects the â€Å"Golden Rule† students will be far less likely to tease and disrespect their teacher and classmates. (Building Classroom Discipline, 11th edition, 2014). Using these two strategies in the classroom will be of great value in the way the classroom is managed. Finally I want to take a look at three behaviors that are exhibited by teachers that cause disruptions in the classroom and halt the learning process. Disorganization, nagging and the inability to leave whatever you have going on at home, at home can cause the classroom environment to feel unsafe and chaotic (Building Classroom Discipline, 11th edition, 2014). Using a combination of strategies from authorities on classroom management can help with these hindrances to education. First knowing what you want your classroom to look and feel like I a huge help in getting and staying organized. Often times teachers become disorganized because they have lost control of the classroom. By establishing your authority in the classroom as suggested by Seganti, you are less likely to lose control and if this does happen it should be easier to regain. Constant nagging of students over trivial matters of work habits or behavior are not helpful. In the long run you are not taken seriously. Students must know how to behave in the classroom. Ensuring as suggested by Wong that students are crystal  clear on expectations and procedures, teachers will spend much less time nagging and more time teaching. Lastly when teachers are unable to leave their home life separate from their classroom the results can disrupt and devastate a classroom. Teachers must before anything else, know their role. As a teacher you are there to provide a safe learning environment for your students. When your personal life interferes with that, learning outcomes and student-teacher relationships are compromised. In my classroom I imagine that by establishing an initial foundation of authority based on my acknowledgement of my role as teacher and educator, I will be able to create safe, fun and effective learning environment. By creating my classroom management style, revisiting it when necessary and setting up rules and procedures from day one, I will have the freedom to teach without disruptions and my students will be able to achieve all of the learning outcomes that have been set for them. Reference Page 1. C. M. Charles Building Classroom Discipline, Eleventh Edition, 2014