Cultural and Racial Inequality in Hemingways Indian Camp Essay

Cultural and Racial Inequality in Hemingway's Indian Camp Hemingway's "Indian Camp" concerns Nick Adams' journey into the unknown to ultimately experience and witness the full cycle of birth and death. Although Nick's experience is a major theme in the story, cultural inequality also is an issue that adds to the the story's narrative range. Throughout this short story, there are many examples of racial domination between Nick's family and the Indians. Dr. Adams' and Uncle George's racist behavior toward the Native Americans are based on the history of competition between Caucasians and America's indigenous peoples. "Indian Camp" begins at the shore where Nick, his father, and Uncle George are picked up by Indians in rowboats. When Nick and the men get into the rowboat, the Indians row them to the Indian Camp, with no help from the doctor or Uncle George. This evidence is the first example of cultural domination in the story. Once across the lake, Uncle George gives the Indians cigars. Uncle George's action could be a gift or a congratulatory gesture for the baby about to be b...

Pcr And Its Use :: essays research papers

PCR And Its Use Often times, scientists only have a small amount of DNA to deal with when doing genetic research or studies. In these situations, scientists can do one of several things. One is to just try to work with it anyway, but this is nearly impossible (depending on how much there is). Ther are a couple other processes they can use, or they can use PCR. PCR is one of the more complicated, but reliable ways to do tests on DNA when they only have a small amount to begin with. PCR, or Polymearse Chain Reaction, is the scientific process used by genetic scientists to clone DNA. "A 'rapid diagnostic' technique used in the clinical microbiology lab to detect pathogens. It relies upon amplification technology utilizingthe heat stable DNA polymerase from a thermophilic organism." (from http://www.genes.com/pcr/pcrinfo.html) Dr. K.Mullis recently received the Nobel prize for inventing the technique. This is how they go about doing this: They first get their small DNA sample. Then they mix all the chemicals (this includes the primer, etc). Then they have to run it through the PCR machine. Here is a (rather detailed) description of the process: "The cycling protocol consisted of 25-30 cycles of three- temperatures: strand denaturation at 95degC, primer annealing at 55degC, and primer extension at 72deg C, typically 30 seconds, 30 seconds, and 60 seconds for the DNA Thermal Cycler and 4 seconds, 10 seconds, and 60 seconds for the Thermal Cycler 9600, respectively." Basically, that means that they set it to certain temperatures, then put it in different cyles for different amounts of time. PCR machines can be compared with washing machines. There are the different temperatures (here for example, there is 72degC, where in the washing machine you would set it to cold/cold respectively. For it to properly replicate, we must know how to match each of the following: A T G A T A T G G C A G C A A C G A C C A T A the match would be T A C T A T A C C G T C C T T G C T G T A T The whole process is pretty much summed up like this: They heat up the DNA to let the enzymes break it down (or 'unzip' its bonds). Then add specific amounts of the primer (relative to the amount of DNA you have. Then you add the enzyme to sets of 4 nuclotides that will go through the genetic sequence of nucleotides and hook up the matching nucleotide (A goes to T and G to C etc).

Psoriasis

Yes, psoriasis can be treated This six-part KULIT article series by the Persatuan Dermatologi Malaysia aims to raise awareness of psoriasis. In this final article, PDM President Dr Allan K C Yee highlights an important message for people with psoriasis – there is no cure yet for psoriasis, but its symptoms can be effectively treated and managed. Be open-minded and willing to work with your doctor to find a treatment that will work for you. The object of treatment is to reduce the extent and severity of psoriasis – the red scaly stigmata, the tell-tale scaling on one’s clothes, the rough cracked palms that make handshakes awkward, painful joints that limit one’s activities. In short, the goal is to improve the quality of life which has been shown in studies to be as affected as much as other major diseases such as cancer, heart disease and depression. The good news is that with today’s medical armamentarium, much can be done to allow the sufferer a greatly improved quality of life. Treatments must be individualized Fortunately, only 20% of psoriatics suffer from severe psoriasis, and the site involved is so variable that the treatments must be individualized. Limited disease can be treated with topical agents but more extensive skin involvement will require oral systemic treatments, phototherapy with artificial UV light, or even injectable agents (biologics). Furthermore psoriasis can affect any part of the body, each meriting special measures. Site-specific treatments For instance, thick scalp psoriasis is often mistakenly treated with endless anti-dandruff shampoos with little results. Scalp psoriasis invariably responds dramatically to tar pomades under occlusion for one to two weeks, a tip that an experienced dermatologist would gladly share with sufferers. Similarly, thick and cracked scaly palms and soles that prevent working with the hands or sometimes even walking, can be significantly improved with special steroid-salicylic acid ointments used under occlusion. These soften and shed the thickened dead skin making the skin pliable and usable once more. Psoriasis affecting the face, body creases – groins, armpits and private areas can be improved with the udicious use of weaker topical steroids and the newer and safer nonsteroidal calcineurin-inhibitors. The problem is that these thinned skinned areas are often treated with strong steroid creams that are not meant to be used in these sensitive areas. The end-result is irreversible side-effects such as ugly pink stretch marks, easy bruising and skin infections. We see a lot of these unfortunate cases who are sold these strong steroids from errant pharmacies without a prescription, or are introduced to them by well-meaning friends and relatives. The Dermatological Society of Malaysia is working with the Ministry of Health to ensure that potent steroids are only available with a prescription. The treatment should not be worse than the disease! Hopefully with warnings such as in this article, the lay public will be better informed about the dangers of self-medicating with potent topical steroids. Topical Treatments Generally, when the extent of psoriasis is limited to less than 5 – 10% of the body surface area (BSA), it is best to use topical treatments in the form of creams, ointments, lotions. As a guide, 1% of the BSA is the area covered by one’s palm. The red, thickened skin in psoriasis is due to the increased multiplication of the skin, allowing the collection of the dead skin layer to be manifested as thick scales. Most effective treatments whether topical or systemic work by reducing the cell multiplication, and by removing the dead skin layers. Time tested agents are coal tar, and anthranols which are messy and brown-staining thus adding further to the stigmatization sufferers feel. More cosmetically acceptable topical agents are steroid creams, vitamin D analogues and calcineurin inhibitors. The latter two are more expensive than the ubiquitous steroid creams but with a superior safety profile. Most psoriatic lesions also tend to be dry and glycerin, urea-based or other humectant moisturizers help relieve soreness and improve recovery especially when used in conjunction with keratolytics – agents that soften and shed the abnormal dead skin layers. Systemic treatments When more than 10% of BSA is involved it becomes impractical to rely on topical measures alone. It may take more than half an hour just to apply creams on large areas of affected skin. Hence, oral or injectable medications are required. Many of these drugs are able to reduce the skin’s cell multiplication or maturation rate eg methotrexate, hydroxyurea, retinoids. However many others suppress the disease process at a more fundamental level by suppressing the activity of abnormal white cells (T-cells) or by neutralizing the T-cells inflammatory chemicals (eg TNF a) eg cyclosporine and the newer biologic agents licensed for use in Malaysia. With the proper use of these systemic agents singly or in combination, it is often possible to control even the most severe cases of psoriasis. However, these systemic agents should only be used by experienced physicians as many of them can have significant side effects. For example, persons with liver disease or gastric ulcers should not be treated with methotrexate; women of child-bearing age should not use retinoids as it can cause fetal abnormalities; persons with high blood pressure or kidney problems cannot use cyclosporine. If a person with severe psoriasis has liver disease, is a woman of childbearing age, or has kidney problems what options then are available for him/her? There are 3 options – oral salazopyrine which only works in 50% of Asians, the injectable biologic agents, or phototherapy (see below). Biologic agents are the new kids on the block. They have a much better safety profile than the above mentioned oral drugs and can be used in persons with liver, kidney disease and women but unfortunately their high cost means relatively few can afford them. Even in the west, where such expensive treatments are reimbursable, the psoriasis must be shown to be non-responsive to conventional oral drugs, or organ toxicities with these drugs are present. Some of them are very helpful in controlling psoriasis as well as the disabling arthritis that affects 10-30% of psoriatics. Phototherapy (PUVA, UVB, nUVB) This is an excellent form of treatment with artificial UV light which is relatively free from serious side effects apart from a small risk of developing non-melanoma skin cancers with prolonged use. This risk is probably not significant in the setting of Asian skin types especially with the newer types of phototherapy equipment such as narrow band UVB (nUVB), and the excimer laser or excimer light. Another advantage of phototherapy is that it is a clean form of treatment, nonmessy and can give a long remission period of up to one year. The main drawback is that it does require visits to the phototherapy centre 3 times a week for 2-3 months. The good news is that most states in Malaysia now have phototherapy units to treat not only psoriasis, but also vitiligo and severe atopic eczema. Alternative therapies In this day and age where the emphasis is on evidence-based medicine (EBM), alternative therapies must prove its worth with hard core scientific evidence from well-conducted clinical studies. Many people with psoriasis who have suffered from the condition for years are, not surprisingly, hopeful for answers, breakthroughs, and even a â€Å"cure† perhaps. Unfortunately, there is no shortage of charlatans offering â€Å"cures† for psoriasis, often in network marketing schemes. One has to acknowledge the fact that psoriasis has a genetic basis, and unless gene therapy becomes a reality, there cannot be a cure, even with accepted treatments such as climatotherapy in the Dead Sea. Diets for psoriasis are as yet unproven, although an FDA-approved healthy diet with at least 5-9 servings of fresh preferably organic produce may be of help in improving one’s general health. Stress reduction strategies may help insofar as stress precipitates and aggravates psoriasis. Prayer has been shown useful in several medical conditions, and a strong faith life can only help, if only to give one the equanimity to deal with the turbulence of modern life. The future of psoriasis treatments There is considerable optimism in the search for better and safer treatments for psoriasis in the near future. We now have a much better understanding of the genetics and underlying immune derangements in psoriasis. It is only a matter of time before the tremendous amount of ongoing research bears better fruit that is sweeter and without the bitter aftertaste of side-effects. Indeed here are promising smaller molecules in the offing that are cheaper to synthesize. Watch out for this space. Psoriasis affects 2-3 percent of Malaysians. This is the final article of a six-part series from PDM’s â€Å"KULIT – Living with Psoriasis† Campaign 2007. For more on psoriasis, treatment options and KULIT, visit www. dermatology. org. my or email [email  protected] com. This article is a guide to help you better understand psoriasis and psoriatic arthritis. Consult a suitably qualified medical practitioner before acting on any information contained above. KULIT is a community programme sponsored by Wyeth Malaysia.

Is It Possible for Organizations Operating in Dynamic Environments to Achieve Person-Organisational Fit to Improve Organizational Effectiveness?

Today we live in a world where change is inevitable. Organisations today face dynamic environments characterized by substantial and often unpredictable technological, political and economic changes. The key to survival and succeeding is adaptation, in dynamic environments often an organisations only option is to literally â€Å"do or die† with regard to change. Tyagi & Gupta (2005) indicates that the central point of personal and organisational effectiveness is a sense of being able to make contributions and make somewhat of a difference in any way possible. As individuals we feel content and fulfilled when we make positive contributions to our communities, families and organisations. Similarly organisations can only achieve their potential when they positively impact the lives of various stakeholders and related entities. However the opportunity to contribute only arises if there is a fit between what people want to achieve and what the organisation wants to achieve. Thus creating a fit between the person and organisation allow both to be effective. In the past few years the concept of Person-Organizational fit (P-O) has been in a state of flux, with many theorists putting forward conflicting views on the conceptualization of fit, its measurements and its boundaries. In the broad sense of the word it is defined as the compatibility between the person and the organisation (Li, 2006). As many organisations operate in dynamic environments; many changes take place and organizations have to cope with these changes by adapting their business and strategies to the turbulent environments. This essay goes on to explore the effects the changes mention have on the P-O fit and if dynamic environment allow organisations to achieve person-organisational fit in order to enhance and reach organisational effectiveness. According to evidence it can be seen that it is possible to achieve P-O fit in dynamic environments however it would not be the ideal tool to implement to improve effectiveness due to the evolving nature of the environment as it hinders growth and discourages innovation which would not lead to organizational effectiveness (Tyagi & Gupta, 2005). P-O fit refers to the extent to which and individual and the employing organization are compatible. There are however many definitions that have been put forward over the years such as value congruence (O’Reilly et al. , 1991), Goal congruence (Vancouver et al. , 1994), needs and supplies demand abilities (Edwards,1991) in addition a personality-climate fit (Ryan and Schmit, 1996). However the most commonly used definition is the value congruence perspective. Verquer et al (2003) value congruence as the extent to which individual and organizational values match. Rynes and Gerhart have gone a step further and pointed out that the P-O fit is more than a mere match, as it usually implies a sense of chemistry (Bellou, 2009). Another way of conceptualising the compatibility between the person and organisation uses the distinction between supplementary and complementary fit. Supplementary fit occurs when a person supplements or possesses characteristics that are similar to other individuals in an environment. This congruence can be differentiated between complementary fit, which occurs when a person’s characteristics make whole the environment or add to what is missing (Tyagi & Gupta, 2005). Further more Cable and Parsons (2001) states that P-O fit is a crucial factor in maintaining a flexible workforce and creating a high degree of organizational commitment in a tight labour market and a competitive business environment. Supporters of P-O fit state that the construct is crucial in the study of organizational effectiveness because it has made improvements to the traditional view of matching skills, knowledge and abilities in predicting if an individual will be successful in a particular organization (Chuang & Sackett, 2005). Ambrose et al, 2008 posit that individuals whose values will result in positive contributions to organizational effectiveness and lower turnover. These models may be under the assumption of static environments; one must apply the dynamic nature of the current environments organisations operate in today. Kammeyer-Mueller (2007) proclaims that even though static and dynamic perspectives are portrayed as mutually exclusive alternatives, they need not be opposed to one another. Research goes on to show that constant external shocks injected into the organisations may result in changes been implemented that affects the P-O fit. These changes may sometimes lead to negative results such as turnover and intention to leave as the employees feel they no longer â€Å"fit† with the organisation. In addition Chatman et al (2008, p. 64) notes that, because a lack of congruence is aversive, â€Å"misfits† are unlikely to remain with that organization. There are also instances when individuals no longer are compatible or unhappy with the fit between the organisations and themselves due to adaptations the company undergoes however choose to remain with the organisation solely because they have no other job options. In instances where â€Å"misfits† remain as they perceive that it is their only choice they bring about many negative aspects into the organisation such as demotivation, low commitment, this is mainly because they try to overcompensate and manipulate the work input output equation to fill the missing void. On the other hand the Social identity theory suggests that another mechanism by which individual dispositions might influence fit within a dynamic context. The social identity argues that the self-concept is a patchwork of various identities, such as demography, occupation, organization, department and workgroup which provide proscriptions for behaviour (Ashworth & Johnson, 2001). It also states that depending on the pressures applied the identity a person adopts will differ. This however does not change the fact that the individual still has within himself or herself, the same core set of identities. Interestingly at least in Oriental Chinese societies, leaders or managers may change their leader behaviours to create a better person-organisation value fit. This study shows that behaviours have positive effects on person-organisational fit. A crucial finding in this study was that even among employees who have been below average O-P fit can be influenced in terms of motivation commitment and trust in their leader by leader behaviours. For example employees working under high team oriented leaders had higher motivation and commitment and trust compared to those under low team oriented leaders. This goes on to show that even though the dynamic environment may affect and the person-organisation fit and sometimes lowers the P-O value fit , organisations can still effectively operate and manage those employees with the proper management and leadership methods (Li, 2006). However this method might not an appropriate universal method to implement as business environments vary across nations due to cultural, legal and other aspects that are followed. However the P-O fit may not be in the best interest of the organization at times and lead to negative results. For example, extremely high levels of person-organization value fit may lead to high levels of conformity and homogeneity. High levels of conformity and homogeneity will bring about a range of adverse effects which may hinder the success of the organisation, by making the organisation and its members far less adaptable to the changes surging in the dynamic environment as well as less innovative (Li, 2006). Some evidence even go to the extent of pointing out that organisations with slight internal variation in employees perspective lead to better performance in the short run but worse in the long run , presumably as a result of inferior adaptation (Li, 2006). Person-Organisation Fit in theory sounds like a tool that should be implemented by every organisation. Taking a closer look one can see that even though initially achieving a fit will lead to organisational effectiveness in the long run it will cause the organisation more harm than good. This is due to the fact that organisation operating in dynamic environments thrives on adaptability and innovation which is opposed by the negative by products of long term P-0 which include homogeneity and high levels of conformity. This does not mean that the concept of P-O should be completely ignored as evidence shows that it has a greater impact on individuals in an organisations resulting in positive results in comparison to organisations as a whole. In an ideal situation the individuals should adapt with the environment and perceive the changes as a learning experience to mould them to achieve the best, keeping in mind that sometime change is the key.

Couplings Elements Essay

Couplings are mechanical elements that ‘couples’ two drive elements which enables motion to be transferred from one element to another. The drive elements are normally shafts. We tend to see lot of applications of the couplings mainly in the automobiles, for example the drive shaft which connects the engine and the rear axle in a bus or any automobile is connected by means of a universal joint. In order to transmit torque between two shafts that either tend to lie in the same line or slightly misaligned, a coupling is used. Based on the area of applications there are various types of coupling available. But they are generally categorised in the following varieties 1. Rigid Couplings 2. Flexible or Compensating Couplings 3. Clutches to are a type of Coupling – We will the dealing on them separately. RIGID COUPLINGS Rigid Couplings are mainly used in areas where the two shafts are coaxial to each other. There are many types of couplings that fall under the rigid couplings category. They are  · Rigid Sleeve or Muff Couplings- This is the basic type of coupling. This consists of a pipe whose bore is finished to the required tolerance based on the shaft size. Based on the usage of the coupling a keyway in made in the bore in order to transmit the torque by means of the key. Two threaded holes are provided in order to lock the coupling in position. The photo shows a type of the rigid sleeve or muff coupling.  · Flanged Coupling – The coupling basically consists of two flanged end pieces as shown in the figure. A spigot and recess is provided in the flanges to provide location between them. The flanges are connected firmly by means of fitted bolts which are tightened accordingly to the torque to be transmitted. FLEXIBLE OR COMPENSATING COUPLINGS Flexible couplings are normally used in areas where the coaxiallity between the connecting shafts is not always assured and in areas where there is a possibility of occurrence of shocks in the transmission is applicable. They are also called as Elastic Couplings. By construction these couplings tend to have a elastic member in between the two connecting entities. The different types of flexible couplings are 1. Flanged Pin Bush Couplings 2. Bibbly Coupling 3. Gear Tooth Coupling 4. Tyre couplings 5. Elastomeric Couplings – This consists of jaw type and S-flex couplings. 6. Oldhams Coupling 7. Universal Coupling or Hooke’s Coupling 8. Bellows Coupling Each of the above couplings are quite unique in their construction and we can deal in detail on their constructional and working aspects in separate articles. BIBBLY COUPLING: This article deals with Bibby Resilient type couplings. The article describes constructional aspects of the coupling and the selection procedures for the coupling. * Named after its Inventor Dr. James Bibby in 1917, this coupling is still one of the most sought after flexible couplings for heavy shock applications. Let us now look at the constructional features of the coupling. 1. The Coupling consists of two flanges or hubs specifically mounted on the drive and the driven shafts respectively. These hubs contain axial grooves cut on their circumference. 2. The two couplings are joined or held together by means of a specially designed grid spring. 3. The total assembly is enclosed in a casing or shell filled with grease for low speed applications or, in high speed application with high viscosity oil. Now let’s look at the working aspect of the coupling and how it tends to reduce vibration and prevents the build up of resonance in the system. a.) The specially designed spring is wound up through the grooves forming a series of resilient bridges throughout the periphery of the coupling. b.) The grooves are tapered up at the edges (see photo) in order to provide extra flexible spans to the spring at normal loads and tends to support the spring at the sides whenever overloading occurs. c.) The stiffness of the spring depends on its unsupported length of each of its flexible span. The unsupported length tends to vary with the loads producing a varying stiffness for the coupling based on the loading. d.) This action tends to produce a detuning action altering the torsional vibration frequency of the system that prevents the build-up of resonance. Some applications of Bibby Couplings are 1. Cement Mills – in grinding and crushing machinery. 2. Cranes 3. Conveyors 4. Turbines 5. Marine Auxiliaries 6. Paper Mills Bibby couplings can be used for applications with powers varying from as low as 1 h.p to about 100,000 h.p. per 100 rpm of the coupling. Correspondingly the couplings are available in varying sizes ranging from 100mm diameter to 4000mm diameter. Bibby couplings are capable of taking axial and radial misalignments to a very small extent only. It is necessary for the user to ensure that both axial and radial misalignments are kept to the minimum possible. Selection procedure for Bibby Couplings: The selection of the Bibby coupling is mainly based on the torque being transmitted by the coupling. Each coupling has a characteristic value for the torque transmitted by it to the revolutions per minute of the coupling. The rating of the coupling is given by Rating = Maximum power to be transmitted in h.p/ r.p.m of coupling In order to account for contingencies like shocks, sudden stops, stalling, etc. a factor of safety is to be considered during selection of the coupling. Rating of coupling to be Selected = Max. power of coupling* Factor/ r.p.m. of coupling The chart containing the factors to be considered is given below based on the application and driving machinery. See the selection chart below for the selection of corresponding coupling based on the power. Note: This chart is an indicative for the selection of the Bibby coupling. Kindly refer to an actual manufacturer’s catalog for selection as ratings may vary from manufacturer to manufacturer. GEAR COUPLING: This article deals with Gear Couplings. The article describes constructional aspects and selection procedures for flexible gear couplings. * Couplings are used as connecting elements between two shafts. The complexity in the type of connectivity, the power to be transmitted and the area of application tend to play a vital role in the selection of the type of the coupling. Gear Couplings belong to the category of flexible couplings that are capable of transmitting very high torques. Constructionally the gear coupling utilizes the advantages of gear engineering; practically the coupling is a complete gear assembly. Let us now look into the constructional aspects of the coupling. 1. The gear couplings consists of a forged sleeve with internal teeth cut on its inside. The forged sleeves are normally two halves possessing internal gears in both of them. In certain cases the forged sleeve tends to remain a single piece. 2. Two hubs with external teeth containing the same number of teeth as in the internal gear is present with each one being mounted on the driven and driver shaft respectively. The tooth profile of the external teeth is normally crowned in order to take up more loads. 3. The entire assembly in normally enclosed and is provided with gaskets at the joints and O-rings at vantage points in order to prevent the leakage of the lubricant filled inside the coupling, 4. Lubrication plugs are provided at vantage points in order to lubricate the couplings during predetermined intervals of time. Tooth forms in the Coupling: Three types of external teeth are used in gear couplings. The only difference is the manufacturing methodology of the same. a.) Straight Teeth: The external teeth in the hub are straight. During the condition of misalignment in the coupling the contact pattern between the internal gear and the external gear tends to be line type of contact as shown in the figure. b.) Crowning with constant radius: The external teeth are barrel shaped with a constant radius in order to increase the area of contact and move the area of contact to a near middle portion of the teeth. c.) Crowning with variable radius: The external teeth are barrel shaped with a variable radius instead of constant radius. This increases the area of the contact significantly compared to that of the constant radius crowning. The maximum degree of misalignment permissible in gear couplings is from 0.5 Degrees to 1.5 Degrees. This varies with the size of the coupling being used. Selection procedure for gear coupling: The gear couplings are selected based on the torque ratings. 1. 1. The torque transmitted by the coupling is to be determined. 2. 2. Based on the application the appropriate service factor needs to be determined. A reference chart on the service factors is shown below. 3. 3. The equivalent torque is to be determined by multiplying the service factor with the torque transmitted. 4. 4. Select the coupling based on the equivalent torque value calculated. A reference selection chart is given below for example. JAW TYPE ELASTOMERIC COUPLING: This article deals with Jaw type Elastomeric coupling. The article describes the constructional aspects of the coupling and selection procedures. * Couplings are indispensable mechanical power transmission elements used for connecting shafts. Flexible couplings in particular are used in areas where misalignment needs to be accommodated (the flexibility is highly restricted based on the type of Elastomeric material used) and also to take up shock loads at the driven end, thus protecting the driving element like a motor or such. Jaw Type Couplings tend to have a flexible member or Elastomeric member between the two metal components. The flexible member is also called the â€Å"Spider.† The Spider material can be made from different types of rubber or plastic possessing varying degrees of hardness in order to suit the load carrying capacity of the system torsional characteristics. The constructional features of the Jaw type coupling are shown below. The dimensional drawing as wel l as the nomenclature of the coupling is also enclosed. Here as some of the key aspects on the constructional features of the Jaw type coupling. These points are to be considered for the proper selection of a coupling. – The metal hub is constructed of sintered iron, cast iron, or aluminium or stainless steel. The type of metal hub is mainly based on the area of operation of the coupling and its inertia aspects. – The spider is normally made up of a nonmetallic element like rubber, urethane, hytrel because of their Elastomeric properties and in very rare cases bronze is used. BEAM COUPLING: A beam coupling A beam coupling, also known as helical coupling, is a flexible coupling for transmitting torque between two shafts while allowing for angular misalignment, parallel offset and even axial motion, of one shaft relative to the other. This design utilizes a single piece of material and becomes flexible by removal of material along a spiral path resulting in a curved flexible beam of helical shape. Since it is made from a single piece of material, the Beam Style coupling does not exhibit the backlash found in some multi-piece couplings. Another advantage of being an all machined coupling is the possibility to incorporate features into the final product while still keep the single piece integrity. Changes to the lead of the helical beam provide changes to misalignment capabilities as well as other performance characteristics such as torque capacity and torsional stiffness. It is even possible to have multiple starts within the same helix. The material used to manufacture the beam coupling also affects its performance and suitability for specific applications such as food, medical and aerospace. Materials are typically aluminum alloy and stainless steel, but they can also be made in acetal, maraging steel and titanium. The most common applications are attaching encoders to shafts and motion control for robotics. Oldham Animated Oldham coupler An Oldham coupling has three discs, one coupled to the input, one coupled to the output, and a middle disc that is joined to the first two by tongue and groove. The tongue and groove on one side is perpendicular to the tongue and groove on the other. The middle disc rotates around its center at the same speed as the input and output shafts. Its center traces a circular orbit, twice per rotation, around the midpoint between input and output shafts. Often springs are used to reduce backlash of the mechanism. An advantage to this type of coupling, as compared to two universal joints, is its compact size. The coupler is named for John Oldham who invented it in Ireland, in 1821, to solve a paddle placement problem in a paddle steamer design. * * it is recommended to use manufacturer’s alignment target values to set up the machine train to a defined non-zero alignment, due to the fact that later when the machine is at operation temperature the alignment condition is perfect Coupling maintenance and failure Coupling maintenance is generally a simple matter, requiring a regularly scheduled inspection of each coupling. It consists of: * Performing visual inspections, checking for signs of wear or fatigue, and cleaning couplings regularly. * Checking and changing lubricant regularly if the coupling is lubricated. This maintenance is required annually for most couplings and more frequently for couplings in adverse environments or in demanding operating conditions. * Documenting the maintenance performed on each coupling, along with the date.[2] Even with proper maintenance, however, couplings can fail. Underlying reasons for failure, other than maintenance, include: * Improper installation * Poor coupling selection * Operation beyond design capabilities.[2] The only way to improve coupling life is to understand what caused the failure and to correct it prior to installing a new coupling. Some external signs that indicate potential coupling failure include: * Abnormal noise, such as screeching, squealing or chattering * Excessive vibration or wobble * Failed seals indicated by lubricant leakage or contamination.[2] Checking the coupling balance Couplings are normally balanced at the factory prior to being shipped, but they occasionally go out of balance in operation. Balancing can be difficult and expensive, and is normally done only when operating tolerances are such that the effort and the expense are justified. The amount of coupling unbalance that can be tolerated by any system is dictated by the characteristics of the specific connected machines and can be determined by detailed analysis or experience.

Media studies Essay Example | Topics and Well Written Essays - 2500 words

Media studies - Essay Example For instance, in Brazil, Samba is seen as music of the young working class, but in Europe and North America, it represents an exotic form of ‘world music’ popular with the educate elite. This explicitly reveals that relationship between culture and social class seems to differ broadly in the world. Thus, ‘class culture’ is a concept created by the debates about the changing structure of class (Kirby 1997: 676). Working Class Culture In the 1950s, affluent group of workers was emerging due to the escalating standards of living in the 1950s and changing working class culture nature, which created a change in political attitudes and middle class lifestyle. According to Kirby, â€Å"Sections of the working class enjoyed access to a range of cultural goods and commodities for the first time, including family cars, washing machines, televisions and holidays abroad† (1997: 676). Kirby further suggests that mass society was created by the emergence of America n cultural products including rock and roll, American movies, and juke boxes and so on, which led to gradual erosion of the working class culture. ... It also emphasized on commitment of one to political involvement and a sense of decency, which, knows right from wrong. The arrival of mass entertainment designed to appeal to all classes slowly eroded the traditional working class culture. The introduction of radio, for example, alienated the need for working-class people to meet and sing their own songs (Kirby, 1997: 677). Stereotypes of the Working Class Culture Stereotypes are based on â€Å"oversimplified and pre-conceived ideas of the characteristics of a particular, situation or group† as displayed in Oxford Dictionary, 1989, â€Å"Stereotype†. In many studies of the working class culture and stereotypes, there has been the dominance of gender. According to Dunk, stereotypes relating to gender are changing. Nonetheless, structures of patriarchy and ideology still have root in the society (Dunk, 2003: 18). Central stereotypes reflect the world concepts of dominant classes who are in a quest for self-actualization at the expense of others below their class. For example, many have stereotyped Blacks as ‘Jezebels whereby women were all perceived as promiscuous (Mankiller, 1998: 565). Alongside racial and ethnic stereotypes, gender and social class are among the most prominent features where people fall. In the society, a complex interplay exists among racial-ethnic, gender and class stereotypes (Andersen, Taylor 2008: 276). Andersen and Taylor further notes that there are gender stereotypes. This refers to stereotypes that focus on a person’s gender. According to these authors, women stereotypes tend to be more negative compared to those of men. The typical woman has been traditionally stereotyped as subservient, flighty, overly emotional, overly talkative

Response for Leon Bonstein Let Teen-agers try adulthood, Paul Raeburn Essay

Response for Leon Bonstein Let Teen-agers try adulthood, Paul Raeburn Too immature for thye deatyh penalty - Essay Example Botstein argues that the social structure in high school is a hierarchical structure that is characterized by age, athletic prowess and attractiveness. The social structure in high school is different from any other community that students come across once they finish high school. The American high school education system is also regarded as obsolete. Botstein stipulates that when high school education system was being designed, students did not mature at the pace that they do today. Students used to mature at a slow pace. For example, Botstein stipulates that the age of menstruation has gone down approximately two years since the 21st century began. In this perspective, Botstein says that children should be allowed to begin school at an early age. The recommended age to begin elementary school today is 4 or 5 years. Botstein also stipulates that the junior high school stage or middle school should be scrapped off. This would allow a student to graduate from high school at age 16 and not 18 years. At this age, most students can be able handle real life situations without encountering significant difficulties. They are also adequately prepared to head off to college. Moreover, the article entitled â€Å"Too Young for Death Penalty† by Paul Raeburn describes a situation whereby Christopher Simons, 17 and Charles Benjamin, 15 led to the death of Ann Crook, 46, when they tied her with a tape and pushed her into a river. The two young adolescents confessed to committing the murder which earned them $6. Benjamin was sentenced to life imprisonment while Simmons was given a death penalty. The death penalty in this case attracted the attention of psychiatrists, psychologists, and other health groups. They argued that juveniles should not be executed since their brains are still in development. This means that juveniles should not be held entirely responsible for activities that they engage in (Raeburn). This is because the activities that adolescents