Polymer: The Glass Transition

Polymer: The Glass Transition Formulation Chemistry Polymer: The Glass Transition In the solid state, semicrystalline polymers exhibit both amorphous and crystalline morphology. The glass transition is a property of only the amorphous portion of a semi-crystalline solid. [1] The glass transition temperature, Tg, is the temperature at which the amorphous materials change between the glassy and rubbery form. 1.1 Amorphous and Crystalline Polymers The amorphous polymers consist of molecules that are oriented randomly, unlike the crystalline ones which have polymer chains packed in ordered, repeating patterns in the three-dimensional crystal lattice. However the glass transition is different to melting because only amorphous polymers undergo the glass transition. Melting is a transition that occurs in crystalline polymers when these chains are disoriented from the crystal structures and become liquid. A sample of semicrystalline polymer can be composed of both amorphous and crystalline portions, therefore it can have both a glass transition temperature and a melting temperature. 1.2 Glassy and Rubbery States Below Tg, the amorphous regions of a polymer are in a glassy state and most joining or contact bonds are intact. [2] The molecules may be able to vibrate slightly, but are virtually motionless in which portions of the molecule wiggle around. Therefore polymer is generally hard, brittle and rigid. As the polymer is heated until it eventually reaches its glass transition temperature, the molecules start to wiggle around. In inorganic glasses, more bonds are broken with increased thermal fluctuations; while in organic polymers, non-covalent bonds between chains also become weaker. By heating above Tg, there is long-range segmental motion where the polymer chains can move around easily. It is now described in its rubbery state which offers flexibility and softness for plastic deformation without fracture. Below Tg, the chains are firm and unbendable to relieve the force being applied. This is due to either (a) the chains are strong to resist the stress; or (b) the force applied is excessive for the motionless polymer chains to overcome, so the polymer sample will just break or shatter.[1] Such mobility with temperature is heavily dependent upon the â€Å"heat† content because Tg is a kinetic parameter. The Tg decreases with slower melt cooling rate. It is also affected by other factors listed in section 1.4. Heat is a form of kinetic energy that causes random motion of molecules and the pliability of polymer, in comparison to â€Å"cold† polymers which lack kinetic energy to move around and hence are brittle on cooling. Example of this behavior is the glass transition of chewing gum. It is soft and pliable at body temperature, characteristic of an amorphous solid in its elastic, rubbery condition. The gum then turns hard and rigid when it comes into contact with cold drink or ice cube in the mouth. 1.3 Glass Transition vs. Melting The differences are outlined in the table below: Generalised Anxiety Disorder (GAD): Theories and Treatment Generalised Anxiety Disorder (GAD): Theories and Treatment Introduction Modern cognitive-behavioural therapy (CBT) grew out of the merging of behavioural therapy, developed in the 1950s to 1970s, and cognitive therapy developed in the 1960s (Graham, 2004). Broadly, it attempts to deal directly with a clients manifest symptoms through both cognitive and behaviour strategies. Cognitive theories target particular irrational beliefs which are thought to be the source of behavioural and emotional problems. Historically, CBT is well-established in the treatment of anxiety disorders, but has only been adapted more recently for use in psychosis (Tarrier, 2002). This essay will first examine the theory and practical treatment of generalised anxiety disorder (GAD) using CBT. Then the treatment of psychosis will be considered in the same way, but concentrating on the similarities and differences to the treatment of anxiety. CBT Treatment of Generalised Anxiety Disorder The main feature of GAD is excessive and uncontrollable worry (Wells, 2002). The DSM-IV states that for a positive diagnosis of GAD, the worry must occur more days than not over a period of six months (American Psychiatric Association, 1994). The DSM-IV also lists a number of somatic and cognitive symptoms which include, for example, muscle tension. A variety of different treatments have been used for GAD including both directive and non-directive therapies. Fisher Durham (1999) examine the effectiveness of different treatment methods and the number of clients making a full recovery. The most successful treatments in their meta-analysis were CBT which achieved a recovery rate of 51% and applied relaxation which achieved a 60% recovery rate. To understand how GAD is treated using CBT, it is necessary to understand the model of worry that it is based upon. Beck (1976) produced the most widely referenced model of anxiety which links emotions and thinking. In this model it is the patients thoughts and images relating to anticipated danger that immediately precede, and cause, anxiety attacks. In appraising their environment, anxious patients overestimate both the likelihood and severity of a negative event occurring and so take defensive action (Blackburn, 1995). Under the umbrella term of CBT a number of different approaches to treating GAD have been used. They normally focus on two main factors: cognitive work aimed at challenging the clients beliefs and thought processes as well as behavioural work teaching anxiety management strategies (Wells, 2002). Borkovec (2002) describes the cognitive aspect of CBT as focussing on how the client perceives the world and attempting to move this onto a more accurate footing. Generally, this is done by eliciting how the client is perceiving events in an anxious way. Then, the client is encouraged to apply logical thought processes to their own perceptions to challenge the way they are thinking. The therapist attempts to supplant these original thought processes with cognitive interpretations that do not lead to increased anxiety. Clients are usually given homework in which they attempt to identify anxiety attacks, what preceded them and what followed them. Hopefully, by demonstrating to the client that their catastrophic predictions do not occur in reality, it is possible to break down the automatic negative thoughts. Some researchers have been critical of this basic cognitive approach as it does not focus on meta-cognitive factors (Wells, 2002). A revision to the model has been added by Wells (1995) who introduces the distinction between Type 1 and Type 2 worry. Type 1 worry is that referred to above the worry about physical symptoms and external events. Type 2 refers to worrying, as it were, about worrying: meta-worrying. Type 1 worrying is dealt with in approximately the same manner described above, but greater focus is given here to Type 2 worrying. Type 2 cognitive interventions focus on two factors: the uncontrollability of the worrying and appraisals and beliefs about the dangers of worrying. Once negative meta-cognitions have been elicited, they can be challenged and worked with in the same way as before. An example of this type of metacognition is that a client can believe that worrying is harmful because it increases blood pressure and thereby this is harmful to the body (Wells, 2002). The therapist would address this by explaining that occasional high blood pressure is not associated with chronic health problems. The second aspect in treating anxiety by CBT is the use of behavioural strategies (Borkovec, 2002). This involves teaching the client techniques for relaxing their body such as meditation, progressive muscle relaxation and relaxing imagery. Clients are encouraged to practice these techniques even when they are not anxious so they feel comfortable with their implementation. In addition, in some circumstances clients will be exposed to situations which make them anxious in order to provide realistic practice opportunities (Borkovec, 2002). A further type of behavioural strategy employed is a stimulus control method. This involves the client in deciding on a period of the day in which worrying will be carried out, carrying out monitoring of their daily worrying, and trying to only worry in the designated period. Then, in the designated period of worrying, clients practice their cognitive skills. Two other techniques used are behavioural activation strategies encouraging the client to engage in more pleasant activities and imagery rehearsal techniques which involve practicing new responses to environmental cues likely to cause worry (Borkovec, 2002). CBT Treatment of Psychosis Unlike the symptoms of anxiety which can be stated relatively succinctly, the experiences of those with psychosis vary to a large degree. Those with schizophrenia-spectrum disorders, for example, can suffer from hallucinations, delusions, perceptual anomalies as well as some associated problems like depression and anxiety itself (Garety, Fowler Kuipers, 2000). The CBT therapist will, therefore, be targeting a greater variety of symptoms than with anxiety, and usually over a much longer period: perhaps three or more times as many sessions as for anxiety. The use of CBT in psychosis was nevertheless developed from the techniques used to treat conditions like depression and anxiety (Tarrier, 2002). CBT is generally used in addition to powerful antipsychotic medications and is aimed at helping clients to better cope with their psychoses. CBT has been investigated in a number of different patient groups, the largest body addresses those with chronic conditions that are treatment-resistan t, with studies generally finding it to be effective (Sensky et al., 2000). More recent studies have found it to be effective in acute and recent-onset schizophrenia (Lewis et al., 2002). The theoretical model for CBT in psychosis is necessarily much broader than that used for anxiety. While the relations between thoughts, feelings and behaviour are important, these have to be set against wider issues. The causes of psychosis are usually multi-factorial and thought to stem from the social environment, biological vulnerability and psychological processes (Garety et al., 2000; see also the stress-vulnerability model: Strauss Carpenter, 1981). In order to reach an effective case formulation, therefore, the therapist needs to examine the confluence of these different factors along with the clients stresses, vulnerabilities and responses. Like anxiety, at the centre of the cognitive model of psychosis lies the idea that the therapist can address all the different types of symptoms by examining cognitive processes. One example Garety et al. (2000) point to was made by Frith (1992), which claims that symptoms of thought insertion are a result of deficits in normal cognitive self-monitoring processes. Similarly, the anxious component of psychosis is seen as resulting from maladaptive appraisals. At heart, the theoretical model of CBT for psychosis relies on the same fundamentals as that for anxiety: that making the client aware of these problematic thought processes will provide some relief. Where it differs theoretically is that it is addressing a wider variety of factors social and biological as well as psychological and so the treatment has to reflect this fact. Turning now to the practical aspects of CBT for psychoses, Garety et al. (2000) outline a six-stage process. The first involves building and maintaining a therapeutic relationship. This was taken for granted in the discussion of anxiety because, to a therapist, this is a given. With psychotic clients, though, there are significantly greater barriers to the building of a therapeutic relationship. The client may well suffer psychotic symptoms during sessions as well as being paranoid about and suspicious of those trying to help them. The second stage is providing cognitive-behavioural coping strategies for the positive symptoms of psychosis (Garety et al., 2000). Similarly to anxiety treatment, this might include reality testing on delusional thoughts, self-monitoring of symptoms and using distraction and withdrawal (Phillips Francey, 2004). The third stage involves attempting to understand the experience of psychosis. Here, the therapist attempts to bring together strands from the clients life and experiences and link them to their psychotic symptoms. Further, however, the therapist also looks to provide some sort of normalisation to the already high level stigmatisation associated with psychosis. This third stage in treating psychosis differs considerably from the treatment of anxiety, which generally does not address wider social issues in depth. Fourthly, the therapist will specifically examine hallucinations and delusions (Garety et al., 2000). This will often be hard as the client will have developed a series of beliefs that are heavily reinforced. These are addressed using standard CBT techniques such as those used in anxiety. Where the approach for psychosis differs, however, is that attempts to change long-held thoughts are not made until well into the therapeutic process and the therapists manner is slower and softer. In addition, compared to CBT for anxiety, there is less emphasis on the patient generating their own alternative interpretations, and more on the therapist providing them. Some clients may not even agree their beliefs are delusional and so the therapist has to work within the boundaries set by the client. The fifth aspect of CBT for psychosis as laid out by Garety et al. (2000) focuses on depression, anxiety and negative self-evaluations. Those suffering from psychosis will often have low self-esteem. This can be the result of long-standing negative self-evaluations which can be targeted by cognitive therapy techniques of reviewing how they arose and then providing a challenge to the thinking. Both depression and anxiety are also treated in this way. Finally, Garety et al. (2000) look at issues of social desirability and risk of relapse. Throughout therapy, the therapist is looking to the future and helping the client to think about their short and medium-term plans. While Garety et al.s (2000) model is influential, it should be noted that the treatment of psychoses, like that for anxiety, is not monolithic there are a variety of different formulations and approaches. Some focus more on particular aspects such as the delusions or coping strategies. Garety et al. (2000) argue, however, that many treatments are now becoming more integrated in order to address the wide range of symptoms in psychosis. Outcomes and Comorbidity The outcome research varies across different types of psychosis and so it is difficult to compare with anxiety outcomes. A further complication is the different methods used and the rapidly developing nature of CBT as an intervention. Psychosis is certainly harder to work with than anxiety because of the sheer number of factors involved and, as a consequence, the outcomes are generally not nearly as good as those for anxiety. One clear similarity between the CBT treatment of psychosis and that for anxiety is their comorbidity in psychotic disorders. Looking across bipolar disorder, schizoaffective disorder and schizophrenia, Cosoff Hafner (1998) found 43% to 45% of psychotic patients had a form of anxiety disorder. Indeed, in their sample, Cosoff Hafner (1998) found that, even though anxiety disorders are often responsive to treatment, none of the patients had been treated for it. Research has questioned whether anxiety might be a dimension of a psychotic disorder like schizophrenia while others suggest they form a subgroup of the patient population (Braga, Petrides Figueira, 2004). Supporting the dimensional view, Lysaker Hammersley (2006) have found a relationship between both delusions and inflexible thought (characteristic of psychosis) and higher levels of social anxiety. Further, looking at schizophrenia in particular, Braga, Petrides Figueira (2004) argue that much of the research shows better outcomes for those treated for comorbid anxiety. While the repertoire, order and specific implementation of techniques used in CBT differs between psychosis and anxiety, the therapeutic relationship will be central to success in both treatments. Factors that Beck Emery (1990) highlight include trust on the part of the client in the therapist, a collaborative approach and a focus on educational issues. Conclusion The treatment of both anxiety and psychosis with CBT is based on identical underlying principles. Theoretically, both approaches involve focussing on the types of attributions and automatic negative thoughts the client is experiencing as well as aspects of behaviour. Similarly, both approaches require a strong therapeutic alliance in order to be successful. The practical implementation of each intervention is, however, tailored for the disorder. The client suffering from psychosis is likely to have a much wider range of symptoms to deal with and, as such, CBT for psychosis generally takes longer and addresses more complex issues. Part of this will involve the therapist in attempting to understand and interpret the experience and causes of psychosis. This is in contrast to CBT for anxiety which will focus more on problem solving. There is evidence to suggest, however, that anxiety forms a part of certain psychoses, and in this situation its treatment should form part of a wider integr ated approach. Finally, outcomes in CBT for psychosis are generally more modest than in anxiety as psychotic symptoms are considerably more challenging for the therapist. References American Psychiatric Association (1994) Diagnostic and statistical manual of mental disorders (4th ed.). Washington DC: American Psychiatric Association. Beck, A. T. (1976) Cognitive Therapy and the Emotional Disorders. New York: International Universities Press. Beck, A. T., Emery, G. (1990) Anxiety Disorders and Phobias: A Cognitive Perspective. Cambridge: Perseus Books. Blackburn, I. M. (1995) Cognitive Therapy for Depression and Anxiety. Oxford: Blackwell Publishing. Borkovec, T. D. (2002) Psychological aspects and treatment of generalized anxiety disorder. In: D. J. Nutt (Ed.). Generalised Anxiety Disorder: Symptomatology, Pathogenesis and Management. London: Taylor Francis. Braga, R. J., Petrides, G., Figueira, I. (2004) Anxiety disorders in schizophrenia. Comprehensive Psychiatry, 45(6), 460-468. Cosoff, S. J., Hafner, R. J. (1998) The prevalence of comorbid anxiety in schizophrenia, schizoaffective disorder and bipolar disorder. Australian and New Zealand Journal of Psychiatry, 32(1), 67-72. Fisher, P. L., Durham, R. C. (1999) Recovery rates in generalized anxiety disorder following psychological therapy: An analysis of clinically significant change in the STAI-T across outcome studies since 1990. Psychological Medicine, 29, 1425-1434. Frith, C. D. (1992) The cognitive neuropsychology of schizophrenia. Hove: Lawrence Erlbaum Associates. Garety, P. A., Fowler, D., Kuipers, E. (2000) Cognitive-behavioural therapy for people with psychosis. In: B. Martindale, A. Bateman, M. Crowe, F. Margison (Eds.). Psychosis: Psychological Approaches and Their Effectiveness Putting Psychotherapies at the Centre of Treatment. London: Gaskell. Graham, P. J. (2004) Introduction. In: P. J. Graham (Ed.). Cognitive Behaviour Therapy for Children and Families. Cambridge: Cambridge University Press. Lewis, S. W., Tarrier, N., Haddock, G., Bentall, R., Kinderman, P., Kingdon, D., Siddle, R., Drake, R., Everitt, J., Leadley, K., Benn, A., Grazebrook, K., Haley, C., Akhtar, S., Davies, L., Palmer, S., Faragher, B., Dunn, G. (2002) A randomised controlled trial of cognitive behaviour therapy in early schizophrenia: acute phase outcomes in the SOCRATES trial. British Journal of Psychiatry Supplement, 43, 91-97. Lysaker, P. H., Hammersley, J. (2006) Association of delusions and lack of cognitive flexibility with social anxiety in schizophrenia spectrum disorders. Schizophrenia Research, 86(1-3), 147-53. Phillips, L. J., Francey, S. M. (2004) Changing PACE: Psychological interventions in the prepsychotic phase. In: P. D. McGorry (Ed.). Psychological Interventions in Early Psychosis: A Practical Treatment Handbook. Chichester: John Wiley and Sons. Sensky, T., Turkington, D., Kingdon, D., Scott, J. L., Siddle, R., OCarroll, M., Barnes, T. R. (2000) A randomised controlled trial of cognitive- behavioural therapy for persistent symptoms in schizophrenia resistant to medication. Archives of General Psychiatry, 57, 165-172. Strauss, J. S., Carpenter, W. T. (1981) Schizophrenia. New York: Plenum. Tarrier, N. (2002) Cognitive-behaviour therapy in the treatment of schizophrenia. In: H. Hafner (Ed.). Risk and Protective Factors in Schizophrenia: Towards a Conceptual Model of the Disease Process. Berlin: Steinkopff Verlag. Wells, A. (1995) Meta-cognition and worry: A cognitive model of generalised anxiety disorder. Behavioural and Cognitive Psychotherapy, 23, 301-320. Wells, A. (2002) Cognitive therapy for generalised anxiety disorder. In: F. W. Bond (Ed.) Handbook of Brief Cognitive Behaviour Therapy. Chichester: John Wiley and Sons. Southwest Airlines: Culture, Values and Operating Practices Southwest Airlines: Culture, Values and Operating Practices Rollin King planned to start low cost airlines that would shuttle passengers between San Antonio, Dallas and Houston. This idea came in his mind due to the complaint of businessmen about the delay of airlines. When all airlines were in losses at that time the Southwest Airlines were earning profit. It was because of the business strategy. They offered lowest and simple charges to get passengers to their destination on time and Muse wanted his executive team to be willing to think independently instead of worked on the institutional practices. One of the things that attract me a lot that there was a plan of profit sharing with senior employees that was first in the airline industry (Arthur A. Thompson, 2008). What grade would you give Southwest management for the job it has done in crafting the companys strategy? What is it that you like or dislike about the strategy? Does Southwest have a winning strategy? Southwest airlines performed successful in the airlines industry. The company demonstrated the ability to quickly dominate markets. Here are some strategies that were really appreciable: Product Positioning Strategy: Southwest airlines carefully projected its image in front of customers and competitors. It offered ticketless travelling by not assigning seats to the passengers so that they could reach the destination on time (Arthur A. Thompson, 2008). Price Strategy: Southwest airlines had offered the lowest domestic airlines charges. There was a plan of profit sharing with senior employees that was first in the airline industry (instituted in 1973) (Arthur A. Thompson, 2008). Promotion Strategy: Southwest airlines wanted to concentrate more on customer preference and benefits. It encouraged its employees to dress casually at work and this created a positive image in front of the customers. (Arthur A. Thompson, 2008). Digital Media Promotion: This was a first airline that developed a web site and online booking facility (Arthur A. Thompson, 2008). One drawback of southwest airlines was that it was taking 6 to 12 rounds in a day. Fuel, air frames and diesel were very costly and southwest airline were not fully boarded. Hence the revenue generation was minimal and the airlines could not make sufficient profits (Arthur A. Thompson, 2008). QUESTION 3 What are the key policies, procedures, operating practices, and core values underlying Southwests efforts to implement and execute its low-cost/no frills strategy? Some policies for the low cost are: The company was operating only one type of aircraft having 737 seats which minimized the spare parts, inventories, maintenance training, and proficient improvement. The company offered ticketless journey which eliminated the expenses of printing and processing paper tickets. The company was serving airports near metropolitan areas and medium sized cities that minimized fuel cost and helped to reach destination on time. Southwest was using point-to-point scheduling of flights instead of hub-and-spoke system which was more efficient in comparison with the later. Southwest didnt have first class section in any of the flights and offered only beverages and snacks (Arthur A. Thompson, 2008). QUESTION 4 What are the key elements of Southwests culture? Is Southwest a strong culture company? Why or why not? What problems do you foresee that Gary Kelly has in sustaining the culture now that Herb Kelleher, the companys spiritual leader, has departed? The company provided free and satisfied environment to the employees. It had positive, innovative and simple culture which contributed to the growth of the company. (Arthur A. Thompson, 2008). Garry Kelly was appointed as vice chairman of the board of directors in 2004. There are some problems that I foresee when Gary Kelly has sustaining the culture: Other rival airlines can copy their spirit and culture that can be problem for the company. Gary was applying changes according to his taste and the company was facing continuous changes. Hence it became difficult to survive in rapidly changing environment. There was no market stability because of the rapidly changes environment (Arthur A. Thompson, 2008). QUESTION 5 What grade would you give Southwest management for the job it has done in implementing and executing the companys strategy? Which of Southwests strategy execution approaches and operating practices do you believe have been most crucial in accounting for the success that Southwest has enjoyed in executing its strategy? Are the any policies, procedures, and operating approaches at Southwest that you disapprove of or that are not working well? The southwest management should get the highest grade in my opinion. Employees maintenance has been crucial in accounting for the success of southwest airlines. The strategy of lowest price with accommodation was very tough but the southwest airlines made it easy (Arthur A. Thompson, 2008). I disapprove due to the following reasons: Southwest should try to expand its existing route. They didnt have Miami International airport as hub even though it is a city of population with a large number in and out flights. Another policy was that the fat people had to take two tickets for being able to sit comfortably in the airline. This was embarrassing to the people who were overweight (Arthur A. Thompson, 2008). QUESTION 6 What weaknesses or problems do you see at Southwest Airlines as of mid-2010? There were some problems that came in the mid of 2010 at the southwest airlines: It depended on only one producer. Southwest was running only one flight of 737 seats there must be some optional flight. Booking of flights became difficult because southwest had eliminated the intervention of agents because of commission amount. Southwest were only focusing on the economy class but have no attention towards business class who were willing to pay for their seats. Money was not the big issue for them (Arthur A. Thompson, 2008). QUESTION 7 Does the Air Tran acquisition make good strategic sense for Southwest? Southwest have a very distinctive and unique culture. The Air Tran acquisition put significant risk. Southwest has one type of plane 737. With the acquisition of Air Tran it started flying the 717 to Mexico and the Caribbean. It was a big shift for southwest (Arthur A. Thompson, 2008). The main base of Air Tran was Atlanta that was a huge delta hub while southwest had started to fly their flights out of the United States. This proves that the acquisition made a good sense not only in business perspectives but also for maintaining the cost effectiveness of the service (Arthur A. Thompson, 2008). QUESTION 8 What strategic issues and problems do Gary Kelly and Southwest executives need to address as they proceed to close the deal with the Air Tran acquisition and contemplate how best to integrate Air Trans operations and Air Trans employees into Southwest? Some problems that need to address Gary and the southwest executives are: Southwest needed to incorporate Air Tran employees into the culture of Southwest that was serving good customer service, lowest costs and lowest charges. To analyze the level of Air Tran employees and the Southwest employees. They have to look on the opportunities and try to enhance business share. They have to analyze that how to conduct flights outside the United States (Arthur A. Thompson, 2008). QUESTION 9 What recommendations would you make to Gary Kelly and Southwest executives as the company heads into 2011? The following are the recommendations for the company: The company has to work on the long term goals. Strategies should be made in accordance with the fuel prices which usually act as a barrier to conventional business growth. Provision should be made for reservations to be performed directly on the site of southwest.com without any intervention of third parties. There must be opportunity for internet marketing. The management of the company should start travelling outside the United States for increasing the market shares. The turnaround time should be improved. The prices of the services should be kept as low as possible. Offering of different types of seating classes with different rates should be helpful for increasing the revenue (Arthur A. Thompson, 2008).