Double Edged Sword Example Essay Example

Double Edged Sword Example Paper The evolution of the world and its civilizations is galvanized by continual scientific and technological progress, which is brought about by the vast reservoir of knowledge that humankind has gained over the centuries in countless attempts to quench their insatiable thirst for the ultimate key that will unlock all the secrets of life. In the last few decades, men and women of science who are determined to fully unveil the mysteries of the universe were already able to take evolution to a whole new level—one that is closer to its culmination. They were able to discover the amazing ability of defying nature and manipulating those which holds the code to the individual characteristics of every living organism: genes. Genetic engineering, or gene manipulation, was once but a very popular element of science fictions and films; now, it has been lifted off the pages and television screens, and has become a reality that can actually help humanity overcome many of its imperfections. However, as this truth shows only a small part of the big picture, the capability of modifying the biological makeup of organisms has generated conflicting views from society. It is best to acknowledge the fact that while recent breakthroughs have presented us with unforeseen promises, they have, at the same time, given us complex predicaments. The educational film DNA: The Promise and the Price introduces the viewers to four immensely powerful molecular biology techniques that may just as well decide the world’s future. With genetic engineering still in its premature stage, only time can tell whether its potential to improve medical technologies—and, subsequently, human lives—outweighs all the socio-ethical, political, and health repercussions that come with it. We will write a custom essay sample on Double Edged Sword Example specifically for you for only $16.38 $13.9/page Order now We will write a custom essay sample on Double Edged Sword Example specifically for you FOR ONLY $16.38 $13.9/page Hire Writer We will write a custom essay sample on Double Edged Sword Example specifically for you FOR ONLY $16.38 $13.9/page Hire Writer Cloning, perhaps the most famous genetic engineering technology of this time, is the process of producing an organism that is genetically identical to its progenitor by vegetative reproduction or a laboratory technique. It holds several medical benefits that once existed only in dreams, books, and movies. For instance, human therapeutic cloning can provide genetically identical cells from embryonic tissues for regenerative medicine, as well as new, healthy tissues and organs that can be used for transplantation. As such, cloning technologies can actually contribute greatly in the research and development for genetic diseases, as well as serious diseases such as cancer, heart diseases, and diabetes. The capability of generating artificial human cells can also lead to further improvements in cosmetic and reconstructive surgeries and burn treatments. Human reproductive cloning, meanwhile, could allow infertile couples to have children with at least some of their DNA. People could even clone themselves to be able to create the â€Å"perfect descendant† for them, or even the loved ones that they have lost to ease the pain of bereavement. However, the main argument against cloning is the fact that it is unethical and morally repugnant to use a human clone to save a life. A clone, though artificially made, is still a life form just like any other human being. To produce and later kill it merely for the sake of our needs would therefore be tantamount to committing a sin. Also, early experiments are most likely to result in a number of clinical failures and lead to miscarriage, the necessity of dozens or even hundreds of abortions, or births of massively deformed offspring. But problems with regards to early experiments pale in comparison to the socio-ethical issues that would surely arise should cloning succeed in producing a healthy child, and become part of the repertoire of new reproductive technologies presently offered to those with sufficient funds. Worse, society would be at a lost as to how to treat human clones. Another product of years of extensive research in genetic engineering is gene therapy, which involves the treatment of a genetic disease through the insertion of normal or genetically altered genes into cells and tissues in order to repair damaged or replace missing genes. It is seen as a potential cure for genetic disorders such as hemophilia, cystic fibrosis, severe combined immunodeficiency, etc. Genes and artificial chromosomes can also be inserted into embryos in a process known as germ-line gene therapy. This could be used to cure genetic disorders, including behavioral disorders such as schizophrenia, or to insert genes which enhance intelligence or athletic performance. The benefits of these genetic changes would be passed on to later generations. Nevertheless, gene therapy is far from perfect; in fact, it has caused the death of many patients who wished to cure themselves of their genetic disorders. Viruses, while the carrier of choice in most gene therapy studies, unfortunately presents a variety of potential problems to the patient, such as toxicity and immune and inflammatory responses. This medical procedure also has several limitations, such as its short-lived nature, as well as the fact this treatment is most suitable only for diseases that resulted from mutations in a single gene. It would be extremely difficult for gene therapy to effectively treat some of the most commonly occurring multi-factorial disorders such as heart diseases and diabetes, which are caused by the combined effects of variations in may genes. The next technique discussed in the film, RNA interference, can be used as a means of silencing gene expression. This can be harnessed to allow specific inhibitions of the function of any chosen target genes, including those involved in causing diseases such as cervical cancer and hepatitis. However, like gene therapy, success is only more likely in those diseases with a simple genetic basis rather than in complex multi-gene disorders. Diseases involving sites where delivery of synthetic RNA is more straightforward will also be more likely to be effectively treated. Also, geneticists are still in the process of improving the RNA interference technique so that they can ensure the procedure’s ability to selectively target cancer cells without destroying any normal cells. The last, and perhaps the most amazing, genetic technology shown in the film is stem cell therapy. Since stem cells are capable of being differentiated into basically all types of cells, they offer so much promise in the development of medical treatments for a wide range of conditions, including heart and brain diseases. Much success and potential has been demonstrated from research using adult stem cells. For instance, many patients with heart diseases who have resorted to stem cell therapy have made great progress in that more of their heart tissues are contracting normally. However—and this is where the controversy lies—the differentiation potential of embryonic stem cells is broader than most adult stem cells. It divides more rapidly than adult stem cells, potentially making it easier to generate a larger number of cells for therapeutic means. As such, it is the most versatile stem cells which can be eventually used to create a new organ. As such, scientists are looking into the use of embryonic stem cells, which could possibly lead to the creation of artificial, healthy organs in a few decade’s time. But, there is a price to be paid: sacrificial lives, in the form of embryos. Harvesting of embryonic stem cells can result in the destruction of human embryos, and even if clone embryos are used, they still count as human lives. As such, it would be very difficult for society to be able to swallow and accept such an immoral way of saving lives, especially those who believe that the end does not justify the means. As can be see, the promise of genetically modifying humans to improve their well being and to treat debilitating illnesses are becoming a reality. By delving deeper into the world of genetics, newfound knowledge may also enable us to go so far as to engineer our own genetic blueprints—to enhance our physical attributes and mental capabilities; to choose the sex, hair and eye color, and even the personality of our children; and, maybe—just maybe—to create seemingly perfect human beings with superpowers. However, despite the enormous amount of development in the field, our moral understanding and awareness is still limited in scope. Our ethical values are still not capable of providing us with adequate tools needed to address the socio-ethical problems posed by advances in genetics. As science outpaces moral understanding, scientists and ethicists are pitted against one another in their struggle to stand by what they believe is for the greater good and to articulate their concerns. While as proponents argue that genetic engineering can prevent and cure more diseases, ethicists believe that the risks—particularly the sacrifice of human lives to save those of others, as well as the after effects of manipulating that which has been ordained by nature—far outweigh the benefits. Humans have the natural tendency to abuse, and as such, the consequential misuse of genetic technologies is but inevitable. For instance, designer babies may be the realization of parents’ dreams for their children to be the best of the best, but altering a baby’s genetic traits and manipulating our own nature may demean the uniqueness of each individual and can therefore undermine our humanity. Children may, in effect, become mere consumer goods for ambitious parents. Gene manipulation, which is seen as a manifestation of the human desire to play God, is capable of entailing horrible social consequences. Society might just be divided between genetically modified humans whose abilities are enhanced and normal humans who don’t possess the same superhuman qualities. Worse, those who are lacking the genetic advantage might just end up becoming the inferior beings, living in a dreadful society with a lot of unimaginable problems. A future driven by genetic revolution seemed bright and wonderful; however, if society fails to expand its moral awareness to cope with the ethical questions that comes with this scientific development, the forces of nature might just catch us off-guard and backlash with a vengeance that we couldn’t possibly escape from. From this, it is apparent that gene manipulation can be likened to a double-edged sword—a weapon lethal against enemies, but with a great risk: it can just as easily kill the one who wields it.

The Tragedy of Reconstruction essays

The Tragedy of Reconstruction essays The Reconstruction: a tragic era? Some professional historians from the 1890s to the 1940s regarded Reconstruction as a tragic era. Was it really a tragic era? Did it adequately fulfill its role in the rebuilding of the Nation? In many ways, it did do its job, such as the abolishment of slavery. But in many other ways, the Reconstruction failed. The real tragedy of this time period, however, was the racism, segregation, and prejudices toward the blacks. It not only affected blacks of that time period, but it also affected blacks for nearly a century to come. First of all, one must analyze the Reconstruction and look at the positive and negative aspects of it. The Reconstruction came to a very abrupt end, leaving much to be desired. Even though the Thirteenth Amendment was passed, abolishing slavery in all of the States, the Reconstruction ended without doing anything to protect the Blacks rights; there was no progress in the fight for Civil Rights. The Reconstruction was also a time of economic depression. During this time period: hundreds of banks folded; 18,000 businesses closed their doors; factories closed; farmers fell deeper into debt. There was also commercial overexpansion and default on railroad bonds. As a result of all of this, the unemployment rate skyrocketed. About fifteen percent of the nation was unemployed. In fact, one quarter of New York City was unemployed. With this depression, the Gilded Age of the North came to an end. With the Election of 1876 and the Compromise of 1877, the Reconstruction also came to an end. Second of all, during Reconstruction, slaves gained their freedom. They, however, did not know what freedom meant. They werent even treated like free men. Their boundaries were restricted by the white men. They could not gain economic, political, or cultural autonomy. The government, who freed the slaves, did nothing to help gain Civil Rights for ...

Business Plan Essay Example | Topics and Well Written Essays - 3500 words

Business Plan - Essay Example One would be in Marlowe Arcade in Canterbury and in Westgate Shopping Centre at Oxford. Both stores shall carry the same products. The business will be financed with  £ 100,000 by a sole proprietor and  £ 200,000 through a business loan from a bank. Sales are estimated to reach about  £ 52,000 average for the first and second year. A positive cash flow is projected at the end of the first year. Prints & Plains shall offer products of various British Designers, from casual wear to formal wear, and to special attires depending on the season. As it caters mainly to women in their 20s and 30s who are already busy with their careers, it would present to this target market a wide array of choices in terms of clothing. It would offer practical get ups for the overly busy working women, and would carry stylish and fashionable ensembles as well. Covent Garden in London is popular for its shops, street performers, bars, restaurants, theatres and the Royal Opera House. It is an Italian style piazza holding restaurants, bars and fashionable boutiques and is known for being the capital’s premier entertainment and leisure destination. (Covent Garden Life.Com. 2007). In it are stores selling the country’s leading designer brands, and it has already a steady host of clients having been in operations for several years now. Marlowe Arcade in Canterbury and Westgate Shopping Centre at Oxford are both popular destinations for both local residents and tourists. They are also the best places to put up Prints & Plains branches as they are situated along busy districts where the hustle and bustle happens. Prints & Plains’s Target Market would primarily be working women in their early 20s to their late 40s, whose monthly salary range is from  £ 10,000 to  £ 50,000. They are the ones who appreciate trend and styles and would spend a considerable amount for nice clothing that would fit

Great Gatsby, Animal farm or When I Whistle Essay - 1

Great Gatsby, Animal farm or When I Whistle - Essay Example Using Nicks perceptions, the writer suggests the distortion and betrayal of that dream. Gatsby pursues wealth and possessions in order to realize his dream of regaining a lost love, a mere illusion. The opulent society in which they exist looks down on ordinary people in the Valley of Ashes (symbol of dirt and poverty). The antagonist, Tom Buchanan shows us, by how he lives, that he has corrupted the dream, destroyed its integrity, has changed and hardened, Both Orwell and Fitzgerald have included a political aspect, of their respective societies; Animal Farm reflecting how Communism destroyed the socialist dream, Gatsby, how the wealthy have distorted the pure ideal of Capitalism. Using the words, thoughts and actions of their characters, they present their views, with dramatic effects both on the stories and their readers. The action drives forward to bitter endings in both instances. While time and place are important, the issues of evil, loss, tragedy and corruption transcend - they can happen anytime, anywhere. Both stories represent telling social and moral comment on how power and wealth can destroy societys In Animal Farm, the writer narrates, outside of the action, an apparently unbiased observer. Despite the animals talking like humans, his clarity of language makes this acceptable. When Old Major dreams, then teaches the animals Beasts of England, asking them to seek freedom, to revolt, the seed is planted for protagonists and reader, signaling the future. Orwell depicts the dreams erosion, introducing evil, using Napoleons antagonistic grasp of power, showing other animals, the dogs, as tools used to banish Snowball. Squealer and Napoleon are the devices by which the writer shows how power can corrupt, how animals/people can be duped. Boxer the horse demonstrates this, declaring Napoleon is always right, despite killings and punishments meted out, allegedly for supporting Snowball, who is also blamed when

Research Paper Essay Example | Topics and Well Written Essays - 2250 words

Research Paper - Essay Example During the transportation, 20 percent of people died due to poor conditions. With some countries burning it in the early 1990s, due to the inhuman nature, human trafficking still exists only with a new name. According to the United Nations Office on Drugs and Crime, paragraph (a) under article 3, of the protocol to prevent, punish and suppress punishing of persons; human trafficking is the recruitment, haulage, harboring, intimidation of a person by use of abduction, fraud, deception, threat, force or by giving or receiving payments with the sole purpose of exploiting the person. The exploitations include sexual exploitation, labor exploitation, and exploitation for prostitution, servitude, slavery or removal of organs. Human trafficking covers all fields; however, the paper will give emphasis to trafficking of women a common and upcoming trend among many countries. Trafficking of Women is an abhorrent crime and currently many women fall into a victim of such instances due to many fa ctors. Advancement in technology among other factors such as economic conditions is the leading causes of trafficking (Shelley 2010, pp. 43). Consequently, many strategies get employed to curb the increasing trend especially among the developing countries. ... It is in this regard that desperate women fall victim and pass across borders into other countries with the sole purpose of sex work. Many women find themselves falling victim of such trafficking practices, when they are promised a better future, which later ends up to be as prostitution. Consequently, women get duped into trafficking due to drug trafficking. There are various organizations trafficking beautiful and attractive women for drug trafficking. This is a case scenario in south Asia and a substantial part of Europe, where girls are capture at a tender age and trained to supply drugs. Trafficking of women also gets promoted by worse economic conditions, which lead to poverty (Shelley 2010, pp. 50). Poverty remains a serious driving factor to trafficking of women. Women especially in developing countries are impoverished with many seeking for means of employment. It is from this perspective that when they are promised marvelous things oversees, they readily accept without know ing what waits. This, therefore, leads to trafficking of such women. Approaches in the current strategies to address human trafficking of women There are various approaches employed by various social groups, governments as well as nongovernmental organizations. One such strategy is the human right framework that outlines various human rights. Using the rights as a basis, various groups fight trafficking of women terming it as an inhuman activity. Some of the human rights include, The right to personal autonomy The right to enjoy psychological, sexual and physical health The right to work with adequate and just pay as well as excellent working conditions Freedom from forced labor and slavery The right not to be

Effects of the Geometrical Conditions on Side Channel Pump

Effects of the Geometrical Conditions on Side Channel Pump Effects of the Geometrical Conditions on the Performance of a Side Channel Pump: A review Appiah Desmond, Zhang Fan, Yuan Shouqi and Osman Majeed Koranteng National Research Center of Pumps, Jiangsu University, Zhenjiang 212013, China Abstract The side channel pump is a type of regenerative pump which plays a role in between the centrifugal pump and the positive displacement pump. This kind of pump delivers a high head at relatively small flows compared with other axial and centrifugal pumps even though it requires a low specific speed. This paper firstly focuses on the physical principle behind the flow characteristics illustrating the complex flow inside the side channel pump. Further discussions disclosed that, the hydraulic performance of the pump greatly depends on the variations of the geometrical parameters. This review draws conclusion that, enhancement of the computational modeling techniques will improve the efficiency of this pump thereby broadening its applications. Keywords: Side Channel Pump, Hydraulic Performance, head, geometrical parameters, computational modeling 1.0 Introduction The side channel pump since its inception in 1920 by Siemen and Hinsch [1] has had great influence in the world of engineering. This pump plays a role in between the centrifugal pump and the positive displacement pump. The side channel pump is a kind of regenerative pump which has a low specific speed and requires minimal Net Suction Pump Head (NSPH). Due to its unique properties to self-prime and transports both liquids and gas, it has been used mainly in the fields of oil and gas industry, mining and other applicable fields. Most of these pumps have the ability to handle liquid with gas or vapor inclusions up to about 50% and also other media close to their boiling point [2]. The side channel pumps base its operation on the momentum transfer principle moving from the impeller blade to the fluid in the side channel of the pump [3, 4]. The side channel pump delivers a large head performance at relatively small flows [5]. The fluid gets into the pump and leaves after numerous impeller movements. The fluid velocity and its head increase causing it to have the capability to produce a head (pressure) compared to the axial and centrifugal pumps. Due to the smaller pressure difference, a fluid entering this type of pump closer to its vapor pressure is less susceptible to the pressure change that can bring about cavitation[4]. Over the years, the enhancement of the total efficiency of this pump still remains a challenge to engineers and scientist. The flow rate of fluid in the side channel pump is significantly influenced by the impeller designs on this basis urgent attention needs to be given to the design and optimization of the impeller and side channel [5, 6]. 2.0 Flow Mechanism The side channel pump mainly features a side channel in figure 1a. and an impeller usually with 18 to 26 blades figure 1b, which delivers the fluid circumferentially. The assembly of the side channel and the impeller is shown in figure 1c. The fluid flows in a straight line from the inlet of the pump and leaves through the outlet in a helical form after numerous re-entries into the rotating impeller. This effect causes an upturn in the pump head (pressure) from about 5~10 times better than the impeller of a common pump rotating at the same speed [5, 6]. side channel (b) radial impeller The assembly of side channel and impeller Figure 1: Typical side channel with radial impeller This makes the flow of fluids in this kind of pump very complex as depicted in figure 2. The pump does not transport the same volume of fluid that enters out meanwhile some portion of the fluid moves back into interrupter gap and is conveyed by the pressure side of the blade to the suction side [6]. Shirinov and Oberbeck [3] explained the movement of gas in the side channel pump. They pointed out that the momentum acquired by the blades of the impeller is transferred to the gas. The velocity of the gas is then increased both in the axial and radial direction by the impeller blades in the side channel. Figure 2. Flow pattern of liquids in the Side Channel Pump [5] The turbulence and the circulation models are largely used to describe the performance of the pump and also the characteristic curve computation. The side channel pump efficiency is usually below 40% because it is a type of a regenerative pump [5, 6]. Basically, the flow is very dependent on the orientation of the impeller, impeller blade and the side channel. There are many configurations of the impeller blade and shapes of the channel as depicted in figure 3 by Song et al. [7]. Figure 3: Different kinds of blade and channel shapes [7] A study by Senoo [8] on the influence of the developing area for different geometries of the inlet region of the regenerative pump observed the large channel region at the inlet port as capable of developing high pressure head leading to a better cavitation performance of the pump. Song et al. [7] developed a model for the flow theory in the regenerative pump to help address the lapses in the works of Senoo[8] and Wilson et al. [9] which mainly concentrated on the exchange of momentum of the flow. There were inaccuracies of some of the models suggested by [8, 9] to reduce the losses and slip factor links. This made the accurate prediction of the off-design flow conditions very incapable. Song and his colleagues [7] concentrated on introducing vibrant mathematical algorithms demonstrating the true behavior of the flow in the developing area of the inlet region. They based their research on assumptions which guided them in arriving at some meaningful conclusions. The velocity triangle relation between absolute velocity, V relative velocity, W and the impeller velocity, U was defined based on the velocity triangle in figure 4 at blade inlet, R1 and blade outlet, R2. Figure 4: Velocity triangle at locations R1 and R2 [7] From figure 5, there is no tangential velocity in the front and rear faces of the blade region. Thereby, the continuity was defined in equation 1 based on their first assumption that the flow should be steady and incompressible. (1) Figure 5: Elements of one side channel and blade [7] They developed the first-order nonlinear Ordinary Differential Equation (ODE) for predicting the circulatory velocity which showed a good agreement when its results were compared with that of experimental results. A new branch of fluid mechanics developed in the last decades called Computational Fluid Dynamics (CFD) has been employed lately in the modern engineering science to analyze the flow of fluids in turbo machines. The study of the fluid flow in the side channel pump using the CFD tool and an analytical method was the centered of BÓ §hle and Mullers [10] research. They developed an analytical model for the flow taking into consideration some assumptions. A momentum balance was expressed for the control volume of the flow in a circumferential course. (2) Where Cin = uniform velocity in circumferential course Csc = uniform velocity in the side channel à ¡Ã‚ ¹Ã‚ exch = mass exchange flow p = static pressure A =Side channel cross-section area A1 = surface control volume à Ã¢â‚¬Å¾ = mean shear stress Figure 6: momentum balance [7] The efficiency of the impeller and side channel was defined as (3) Where ÃŽÂ ·imp = impeller efficiency Pexch = Exchange work Power Pshaft = Power of shaft Phydr = Hydraulic power losses (4) Where ÃŽÂ ·sc= side channel efficiency Peff = effective power à ¡Ã‚ ¹Ã‚  = side channel pump mass flow g = acceleration due to gravity H = head of side channel pump Cin = uniform velocity in circumferential course = flow rate volume A =Side channel cross-section area Based on the efficiencies of the impeller and the side channel, the efficiency of the side channel pump, ÃŽÂ · was computed to be (5) Later, Kristof and his colleagues [11] also applied the CFD to model the flow course in the side channel pump as displayed in figure 6. A technique was modeled to optimize the orientation of the blade and the shape of the side channel to control the flow losses. They carried out simulations with the k-à Ã¢â‚¬ ° turbulent conditions based on a 40100 cell tetrahedral mesh. Figure 6(a) and (b): Typical flow course with the side channel pump [11] In 2005, Engeda and Raheel [12] presented mathematical tools capable of examining the complex flow inside the regenerative pumps. These mathematical tools were used also used to develop the prediction performance code for regenerative pumps 3.0 Effects of the Geometrical design of the parameters of the Side Channel Pump The performance of the regenerative pump was examined by Iverson [13] with his focus on the shear stress generated by the impeller on the fluids. He then confirmed on his resulting expressions (two shear coefficients and an average impeller velocity) through experimentations. A mathematical tool was proposed by Wilson et al. [9] to investigate the performance of regenerative pumps which used radial blades. Equal pressure head rise and circulatory velocity through the channel region was anticipated by Wilson and his team. Much attention was given to the spiral flow to achieve many ways of curtailing the losses. Their results provided experimental verification after comparing the numerical and experimental performance curves. Yoo et al. [14] also tried to develop advanced mathematical equations to calculate the geometry of the rotating flows. They offered enhanced models to examine the flow rate, the average radii of the inlet and outlet impeller and the slip factor based on the exchan ge of momentum proposal by Wilson et al [9]. The models required an experimental boost to evaluate an empirical number in the proposed experimental model. The effect of the blade angle was not considered thus limiting the applicability as a design tool. The variation of the radial blade numbers, the clearance and the channel region of regenerative pumps were conducted by Shimosaka and Yamazaki [15]. Investigations conducted by varying the dimension of flow channels, impellers and clearances on a regenerative pump concluded that, the characteristic dimension of the flow channel is related to the clearances effects, which in turn influences the pump efficiency. The characteristic dimension of the flow channel was introduced as a special dimension which was given as: (6) Where Rmis the characteristic dimension of flow A is the cross-sectional area of the flow channel is the circumferential length of the blade(vane) Figure 7: Flow channel and blade profile They reported that a suitable Rm would yield a high efficiency of the pump. Therefore, the value of the Rm determines the permissible clearance. The pump efficiency was also strongly influenced by the number of blades (vanes) which is dependent on the characteristic dimension of the flow channel, the thickness and length of the blade and the width ratio as shown in figure 7. It was established that the efficiency of the pump varies with different width ratios of the vane groove which aids in the determination of the blade number. Width ratio,(7) Defining Z = Number of blades D = Diameter of impeller t1 = Peripheral width of blade groove t2 = Peripheral length of blade groove Additionally, Yamazak et al. [16] also carried out works to investigate the efficiency of the regenerative pump. Unlike Shimosaka and Yamazaki [15], they used the non-radial blades and concluded that the blade angle and the cross-sectional area of the flow channel play a vital role in the determination of the head (pressure) loss in the flow channel. Άh = Hs Hmin(8) Where Άh = the magnitude of head loss Hs = the suction head Hmin = the minimum pressure head in flow It was noted that the magnitude of Άh reduces to almost half that of water with the same velocity in the event of high viscous liquid. Motivated especially by the observations made by [15, 16], Grabow [17] also took into consideration the effects of the impeller, the number of blades and the role of the radii and thickness of the blades during his research study. The blade angles were varied to define a very satisfactory exchange of energy and pressure head levels, which in effect helps to evaluate cavitation performance better. Bartolini and Romani [18] also affirm that, the flow rate of the regenerative pumps depends on the optimization of the impeller flow. A new theory was proposed by Badami [19] on the calculation of the circulation flow rate of the regenerative pumps. This model took into account the field of the centrifugal force in both the side channel and the blade orientation. Also, his work also considered the influences of the geometry of the blades (number and angles) and the area of the side channel. Earlier it had been discussed by Sachs and Shirinov [20] that the best number of blades depends directly on the diameter of the impeller and inversely proportional to the side channels size. After that work, Shirinov and Oberbeck[3] then focused their investigations on the transportation of gas in the side channel pump by using different blade profiles. They compared C, V, and Y blade profiles with the radial (T) blade profile as shown in figure 8. Figure 8: Impeller with different blade profiles After comprehensive comparisons, it was established that blade profile C gave an optimal performance at pressures exceeding 20kPa meanwhile at pressures from 100Pa to 20kPa, the impeller with blade profile V (Chevron) recorded an optimal performance because there was a high transfer of momentum from the impeller to the gas inside the side channel within such pressure range. An extensive experimental research was also conducted by Choi et al. [21].Their work was mainly focused on the limitations of [14, 15, 17]. They examined the effects of the geometry on the blade on the efficiency of regenerative pumps. Ten different configurations of blades which comprised straight inclined blades with angles of 0 °,  ±15 °,  ±30 ° and  ±45 ° and chevron impeller blade with chevron angles of 15 °, 30 °, and 45 ° were used in conducting the experiments. The measured performance of the pump were measured based on the dimensionless flow à Ã¢â‚¬ ¢, head coefficient, à Ã‹â€ , efficiency, ÃŽÂ · and power coefficient, à Ã¢â‚¬Å¾. (9) Where Q = volumetric flow rate Qs= rigid-body rotational volume displacement rate (10) H = head Ug = rigid body rotation velocity g = acceleration due to gravity (11) The experimental results showed that the pressure head and the pump efficiency is greatly related to the geometry (shape and angle) of the blade as revealed in figure 9(a) and 9(b). Figure 9(a). Pump curve characteristics for the different blade orientation [21] Figure 9(b). Efficiency curve characteristics for the blade orientations [21] The chevron blade(V-shaped) with chevron angle of 30 ° recorded the highest head performance with a better pump efficiency as revealed in figure 8(a) and 8(b) after a comparative test of all the ten blades showing that there was an optimum chevron angle of around 30 °. This report showed good agreement with the work of [3] because of the high energy transfer at high pressures. The variation of the Reynolds number plays an important role in the performance of the regenerative pump computationally and experimentally. It was established by Horiguchi et al. [22] that, as the Reynolds number declines the pressure head of the regenerative pump rises at low flow rate and reduces at high flow rate. This effect of the Reynolds number is greatly affected by the degree of the shear force applied the impeller and the shear stress exerted by the fluid on the casing wall. Meakhail and Park [23] with the help of the CFD put forward an improved model to enhance the efficiency of the re generative pump. They based their arguments on the experimental works conducted by Meakhail et al. [24], Abdou et al. [25] and Abd El-Messih et al. [26] on the same kind of pump. They then confirmed their numerical model with the experimental results which were in good correlation. Figure 10a: Spiral flow course [23] Figure 10b: Impeller and Side channel dimensions [23] The improved model considered the tip (ÃŽÂ ²2), side (ÃŽÂ ²2s) and inlet (ÃŽÂ ²1) angles since a part of the fluid flowing leaves at the tip of the impeller and the other part of the fluid leaves at the side as indicated in figure 10. The CFX software was used to compare the efficiency of the pump with radial blades of different ÃŽÂ ²2s at the tip of the blade and ÃŽÂ ²1 for the same ÃŽÂ ²2. They confirmed that the side-blade angle has a significant effect on the performance of the side channel pump. The FLUENT software was applied in the examination of the flow of the fluid in this kind of pump by [27, 28]. The experimental results corroborated the CFD analysis. They also used a one-dimensional method to describe the energy transfer inside the regenerative pump and estimate the influence of the geometry of the blade on the efficiency of the pump. The performance of the regenerative pump was examined by Karanth et al. [29] numerically with the help of CFD. They studied the complex nature of the flow of fluid inside the regenerative pump. It was discussed that the number of impeller blades had a great significant on the performance of the pump. The head performance of the pump appreciates with the increase in the number of blades. Following the works of [29] the CFD was also applied by Maity et al. [30] to simulate the flow of fluids in regenerative pumps. It was established from their work that the pressure head loss can be minimized by curving the outlet flow domain as indicated in figure 11. Figure 11: Regenerative Pump model displaying the curvature in the outlet domain [30] It was indicated that there is a high rotating stalling flow at the outlet of the pump because of the reduction of the area. This effect enhances the static and total pressure across the pump. Hence, the curvature in turn increases the net pressure head by reducing the vortex flow as in shown in figure 12. Figure 12: Bar diagram showing the total pressure for the Pump model with outlet domain curvature [30] They also ended that, the net pressure is significantly enhanced by locating the blades on either side of the impeller by offsetting. Moreover, the net pressure is also affected by varying the number of blades on either side of the impeller. Fleder [31] numerically and experimentally examined the effects of the geometry of the blade on industrial side channel pumps in 2012. Two different impeller blade profiles were developed using ANSYS CFX 13.0 and subjected to investigations as shown in figures 13 and 14. Figure 13: Design of the Side Channel Pump [31]Figure 14: Impeller Blade Profiles [31] He concluded his work after comparison of the computational and experimental results. The experimental validation was done with a rotational speed of 750 rpm. The Imp 1 depicted good accordance both numerically and experimentally. Meanwhile, Imp 2 recorded a faster head rise because of the higher circulation frequency. This, in turn produces a greater multi-stage influence as depicted in figure 15. Figure 15: Assessment of the pressure head performance of the simulated and experimental results for Imp 1 and Imp 2[31] In addition, Fleder again with Bohle [32] carried out advanced studies to improve the performance of the side channel pump. In this paper, they extended their scope not only to cover the blade profile. The impeller diameter, the size of the gap, interrupter size, side channel height and the shape of the side channel were the main parameters considered. Variation of the height of the side channel, h, the width of the blade, w and the length of the blade, l, were applied to two different pump models in figure 15. Pump Model A Pump Model A Impeller Diameter = 150 mm Impeller Diameter = 160 mm Gap Size s, = 0.2 mmGap Size s, = 0.4 mm Interrupter size = 300Interrupter size = 460 Side Channel height, h = 35 mmSide Channel height, h = 40 mm Shape of Side Channel = semi-circleShape of Side Channel = Straight Figure 16: Variations in the pump models A and B [32] Figure 17: Parameters of the Side Channel Pump [32] The ICEM software was applied to develop the computational models which were meshed using the structured hexahedral multi-blocks grids. They chose k-w-SST profile to assess the flow fluctuations. It was gathered that the efficiency of the pump is dependent on the ratio of the side channel height, h to the blade length, l. Furthermore, sharper pressure head features and meaningfully greater efficiencies are achieved with a gap reduction of the pump. The work done by [21, 31, 32] on the influence of the blade angle motivated Nejadrajabali et al.[4] in 2016 also to analyze the pattern of the flow and the improvement of the efficiency of the pump by modifying the geometry of the blades. Their focus was on the effect of the variations of the angle of the blade, ÃŽÂ ² numerically on the efficiency of the regenerative pump such as the side channel pump. The investigations were carried out using two sets of impellers i.e. (the symmetric blade angles and asymmetric blades angles). The symmetric blade angles were designed with the same inlet and outlet angles of  ±10o,  ±30o and  ±50o whiles the asymmetric blade angles were also designed with the inlet set to 0o and different outlet angles ranging from  ±10o to  ±50o as illustrated in figure 18. Forward/backward ÃŽÂ ²1,2 =  ±10o Forward/backward ÃŽÂ ²1,2 =  ±30o Forward/backward ÃŽÂ ²1,2 =  ±50o Symmetric blades with equal inlet ÃŽÂ ²1 and outlet ÃŽÂ ²2 angles Forward/backward ÃŽÂ ²2 =  ±10o Forward/backward ÃŽÂ ²2 =  ±30o Forward/backward ÃŽÂ ²2 =  ±50o Asymmetric blades with inlet ÃŽÂ ²1 = 0o Figure 18: Geometrical designs of impellers [4] These geometrical designs were well enhanced with the application of the CFX software using the Reynolds decomposition to evaluate the complete 3D Reynolds-averaged Navier-Stokes equations. It was pointed out after the numerical simulations that, the forward symmetric blade angles compared with the other models recorded higher coefficients of heads and displayed a better performance. Recently, Zhang together with his colleagues [33] improved the head pressure performance of the side channel pump by varying the suction side blade angles from 00 to 300 as indicated in figures 19 and 20. Figure 19: Cross-sectional area of the blade [33] Figure 20: The impeller with various suction side blade profile angles indicating ÃŽÂ ¸ = 100, ÃŽÂ ¸ = 200 and ÃŽÂ ¸ = 300 [33] The CFX 14.5 commercial software was used to simulate the turbulence based on the k-w SST model. After experimentally comparing the results with the numerical simulations, it was recognized that the head performance appreciates with increasing suction side blade angles within a certain range. Even though the impeller blade profile with suction angle 300 recorded the optimal head performance, there was no significant advancement in the efficiency of the side channel pump. The regenerative pump (side channel pump) records efficiencies lesser than other types of pumps like the axial and centrifugal pumps. BÓ §hle et al. [34] lately attempted to improve the efficiency of the side channel pump by using the direct method in the context of the CFD simulations to calculate the massive losses which are associated with the various kinds of internal flow patterns of the fluid. The second law of thermodynamics was main physical principle applied in the estimation of the internal losses due to the flow patterns. According to Spurk and Aksels [35] proposal expressed in equation 10, the specific entropy s is a state variable agreeing with the second law of thermodynamics appreciates in all real and irreversible mechanical process in the case of turbomachinery. (12) Where = density of the fluid s = specific entropy u = velocity component in x direction v = velocity component in y direction w = velocity component in z direction x = x coordinate y = y coordinate z = z coordinate = heat flux density vector = Dissipation = local dissipation by heat transfer After the applications of three different models ( i.e. k-à Ã‚ µ model, k-à Ã¢â‚¬ ° model and the k-à Ã¢â‚¬ ° -SST model) to calculate and locate the coefficient of the losses, they remarked that the k-à Ã‚ µ model and k-à Ã¢â‚¬ ° model predicts estimates regions of higher coefficient of losses matched to the k-à Ã¢â‚¬ °-SST model. 4.0 Conclusion Though there have been several investigations into the theory of the flow principle of the fluid and variation of the geometry of the impeller and side channel, t

A Comparison of Thomas Grays Elegy (Eulogy) Written in a Country Churc

A Comparison of Thomas Gray's Elegy (Eulogy) Written in a Country Churchyard and Bryant's Thanatopsis  Ã‚     Ã‚   Thomas Gray and William Cullen Bryant both chose to write about nature and death being intertwined. Since Thomas Gray lived in a time of social injustice, he chose to use death to illustrate the problems inherent in a socially stratified society. William Cullen Bryant, on the other hand, lived in a rapidly expanding young nation that cherished the vast amounts of untouched nature and he used death to illustrate how man fits into the universal truth of the earth. However, both men believed that death rendered all men equal in that all went to their final resting place in Mother Nature's bosom. While Gray's "Elegy Written in a Country Churchyard" comes across as a social commentary on the English peasants and Bryant's "Thanatopsis" serves as a catalog of American Romantic beliefs, both believe that one must listen to nature, that death makes all men equal, and that man returns to nature after death. To compare how the poems minor themes are similar, one must first understand their major themes' differences. "Elegy" differs so greatly from "Thanatopsis" because they came from vastly different times and countries. Gray wrote "Elegy" in eighteenth century England after the death of one of his friends. Influenced by the English Romantics like Gray, Bryant, who spent much of his time out in the wild, wrote "Thanatopsis" in praise of nature's splendor. "Elegy" appears at first to be solely about death but emerges as a social commentary on the plight of the poor. Gray first explains how the commoners delight in the simple life of working in the fields and enjoying their families while "Chill Penury" held them back from gr... ...    Brady, Frank. "Structure and Meaning in Gray's Elegy" Thomas Gray's Elegy Written in a Country Churchyard. New York: Chelsea House Publishers, 1987. 7-17.    Carper, Thomas. "Gray's Personal Elegy" Thomas Gray's Elegy Written in a Country Churchyard. New York: Chelsea House Publishers, 1987. 39-50.    Lonsdale, Roger. "Poetry of Thomas Gray: Versions of the Self" Thomas Gray's Elegy Written in a Country Churchyard. New York: Chelsea House Publishers, 1987. 19-38.    McLean, Albert. William Cullen Bryant. New York: Twayne Publishers, Inc, 1964. 65-81.    Smith, Eric. "Elegy Written in a Country Churchyard" Thomas Gray's Elegy Written in a Country Churchyard. New York: Chelsea House Publishers, 1987. 51-67.    Peckham, Harry Houston. Gotham Yankee. New York: Russell and Russell, 1971. 31-35.   

History of Fire Sprinklers Essay

Rome, 64 A. D. Emperor Nero watched in horror as the great city of Rome burned for six days and seven nights. Afterwards 70% of the city was left in smoldering ruins and devastation. (The Burning of Rome, 64 AD 1) Why the exact cause of the fire is unknown, we wonder if an effective sprinkler system could have prevented this incident and others like it. A city that was well known for their magnificent construction, architecture, and irrigation systems was almost completely destroyed by one incident. Many codes do not require a specific type of Automatic Sprinkler System. While the most common type found is the Wet Pipe System; Dry Pipe, Preaction, and Deluge Systems can be found in many different occupancy types. The two main purposes of automatic sprinkler systems are to extinguish fires and control the fire until appropriate personnel arrive to extinguish the fire. Automatic sprinkler systems are expected in all occupancy types, except residential, unless the hazard is not compatible with water. For these hazards there are several other types of suppression systems that can be installed to manage the incident. By installing an automatic sprinkler system, you increase life safety and property protection. What is the standard of sprinkler systems? The goal is to increase life safety and decrease property damage. The National Fire Protection Association (NFPA) has been the leader in mandating standards and requirements when it comes to sprinkler systems. They have developed many standards that address the installation, inspection, and maintenance of sprinklers. Wet pipe systems are closed water systems attached to a piping system containing pressurized water at all times. This type of automatic sprinkler system is the most common type, and can be found in all most all occupancy types. Unless the potential of freezing pipes or other special conditions apply, this type of system will be encountered most frequently. The operation of this sprinkler system is very simple. The wet-pipe system consists of sprinkler heads attached to sprinkler supply lines that interlace the occupancy. When a fire first starts there is minimum heat generated. As the fire grows and the thermal layer is disturbed, heat rises to the targeted sprinkler heads. Depending on the rated temperature of the sprinkler head, a fusible disc or link melts from the heat and initiates the flow of water. While most fires are controlled by one or two sprinkler heads, in the case of fast moving fires more may be needed to control the fire. When water is flowed from the system, typically other things may happen. In all most all wet-pipe systems, there is some type of audible alarm activated at the standpipe. This will trigger other alarms in the building, and most of the time notifies an agency that will then notify the Fire Department of a water flow alarm or others like it. Dry pipe systems use air or nitrogen to keep the supply line pressurized at all times. This type of automatic sprinkler system is commonly found in the colder areas where the possibilities of freezing pipes are encountered. Dry-pipe systems provide the same adequate protection similar to wet-pipe systems. The piping is charged with air or nitrogen, and when a sprinkler head is activated the drop in the pressure opens a valve at the standpipe that allows water to flow into the systems. (Bahme 25) Just like the wet-pipe system, normally one or two sprinkler heads are needed to control the fire. There will also be an alarm that is activated notifying the appropriate agency to contact the Fire Department. At lest once a week the system should be tested to make sure that the air pressure within the piping is maintained. The third type of automatic sprinkler system is the Pre-action System. This type of system is a closed piping system that contains air, which may or may not be under pressure. When a fire occurs the fire detecting device signals the control valve to open charging the system. This type of system is usually used where the possibility of broken pipes and sprinkler heads may result. The most common places found include electrical rooms, computer rooms, and other areas that may house expensive equipment. There can be several types of pre-action system including a recycling system. This system is capable of charging the piping, discharging water, then cutting itself off. In the event that the fire rekindles, it can discharge again. It then has the ability to recycle the water. Deluge systems are much like Pre-action systems except that the sprinkler heads are open and the system is not charged. Similar to that of the pre-action systems, a fire detection device, usually a heat sensor, activates the discharge valve on the system. The difference is that the entire sprinkler component of the system is open; therefore the area that is activated is deluged in water. These types of automatic sprinkler system can be found where a high hazard of flammable liquid may be encountered. The most common place is aircraft hangars. Caution should be taken though; in confined spaces the oxygen level can be deficient when these systems are activated due to the copious amounts of water. Combined Dry-Pipe and Pre-action systems are composed of both the systems mentioned above. These systems have the dry pipe features with the pre-action features in the event the dry pipe portion fails. These systems are used when an area is too large to be covered by a dry pipe system. On the same note though, combined systems were originally developed for protection during cold climates. Long lines would be subject to freezing. These systems are commonly found when dealing with long piers. (Bahme 30) It is important to note this type of system is considered two independent systems. Testing requires individual standards for both type; consisting of the dry pipe system and the pre-action system. Limited water supply systems are those where supply water cannot be properly supplied to the occupancy. These systems consist of many wide range types and can be used as outside sprinklers and confined space sprinklers. Some research obtained shows that one type of limited water sprinkler type could be the antifreeze sprinkler system. This type of system is very uncommon and is normally not accepted and used in recent automatic sprinkler systems. In conclusion, there are several types of water sprinklers used in today’s management to help increase life safety and decrease property damage. By including detection devices and the correct sprinkler heads, these systems can mean the difference between life and death. The occupancy should have the correct automatic sprinkler system that will properly suppress the material relevant in that occupancy regardless of the type. The preferred automatic sprinkler system should all be able to notify the occupants, summon the correct agency to suppress the fire, sound alarms, supervise fire control, and initiated a wide variety of auxiliary functions involving environmental, utility, and process controls. (IFSTA 559)

Spanish Proverbs and Quotes for Your Life

Spanish Proverbs and Quotes for Your Life Like their English counterparts, Spanish proverbs often capture the wisdom of the ages with timeless advice about life. En boca cerrada no entran moscas Translation: Flies dont enter a closed mouth. (You wont make a mistake if you dont talk.) Here are enough proverbs to last for a month. To test your vocabulary or stretch your interpretation skills, try translating them and coming up with an English equivalent, although be warned that there isnt always a direct English counterpart. Very loose translations or English equivalent proverbs are in parentheses. 31 Spanish Proverbs, Quotes, and Sayings El hbito no hace al monje. The habit doesnt make the monk. (Clothes do not make the man.)A beber y a tragar, que el mundo se va a acabar. Heres to drinking and swallowing, for the world is going to be finished. (Eat, drink and be merry, for tomorrow we die.)Algo es algo; menos es nada. Something is something; less is nothing. (Its better than nothing. Half a loaf is better than none.)No hay que ahogarse en un vaso de agua. It isnt necessary to drown oneself in a glass of water. (Dont make a mountain out of a molehill.)Borra con el codo lo que escribe con la mano. He/she erases with the elbow what his/her hand is doing. (His right hand doesnt know what his left hand is doing.)Dame pan y dime tonto. Give me bread and call me a fool. (Think of me what you will. As long as I get what I want, it doesnt matter what you think.)La cabra siempre tira al monte. The goat always heads toward the mountain. (The leopard doesnt change its spots. You cant teach an old dog new tricks.)El amor todo lo puede. Love can do it all. (Love will find a way.) A los tontos no les dura el dinero. Money does not last for fools. (A fool and his money are soon parted.)De mà ºsico, poeta y loco, todos tenemos un poco. We all have a little bit of musician, poet and crazy person in ourselves.Al mejor escribano se le va un borrà ³n. To the best scribe comes a smudge. (Even the best of us make mistakes. Nobodys perfect.)Camarà ³n que se duerme se lo lleva la corriente. The shrimp that falls asleep is carried by the current. (Dont let the world pass you by. Stay alert and be proactive. Dont fall asleep at the wheel.)A lo hecho, pecho. To what is done, the chest. (Face up to what is. What is done is done.)Nunca es tarde para aprender. It never is late for learning. (It is never too late to learn.)A otro perro con ese hueso. To another dog with that bone. (Tell that to someone who will believe you.)Desgracia compartida, menos sentida. Shared misfortune, less sorrow. (Misery loves company.)Donde hay humo, hay calor. Where theres smoke, theres heat. (Where theres smoke theres fire.) No hay peor sordo que el que no quiere oà ­r. There is not a worse deaf person than the one who doesnt want to hear. (There is none so blind as he who will not see.)No vendas la piel del oso antes de cazarlo. Dont sell the bears hide before you hunt it. (Dont count your chickens before they hatch.)Quà © bonito es ver la lluvia y no mojarse. How nice it is to see the rain and not get wet. (Dont criticize others for the way they do something unless youve done it yourself.)Nadie da palos de balde. Nobody gives sticks for free. (You cant get something for nothing. Theres no such thing as a free lunch.)Los rboles no estn dejando ver el bosque. The trees arent allowing one to see the forest. (You cant see the forest for the trees.)El mundo es un paà ±uelo. The world is a handkerchief. (Its a small world.)A cada cerdo le llega su San Martà ­n. Every pig gets its San Martà ­n. (What goes around comes around. You deserve what you get. San Martà ­n refers to a traditional celebration in which a pig is sacrificed.) Consejo no pedido, consejo mal oà ­do. Advice not asked for, advice poorly heard. (Someone who doesnt ask for advice doesnt want to hear it. Dont give advice unless youre asked.)Obras son amores y no buenas razones. Acts are love and good reasons arent. (Actions speak louder than words.)Gobernar es prever. To govern is to foresee. (It is better to prevent problems than to fix them. An ounce of prevention is worth a pound of cure.)No dejes camino viejo por sendero nuevo. Dont leave the old road for a new trail. (Its better to stick with what works. A short cut isnt always quicker.)No dejes para maà ±ana lo que puedas hacer hoy. Dont leave for tomorrow that which you can do today.Donde no hay harina, todo es mohina. Where theres no flour, everything is an annoyance. (Poverty breeds discontent. If your needs arent met, you wont be happy.)Todos los caminos llevan a Roma. All roads lead to Rome. (Theres more than one way to reach a goal. All actions have the same result.) And a Bonus Handful La lengua no tiene hueso, pero corta lo ms grueso. The tongue doesnt have a bone, but it cuts the thickest thing. (Words are more powerful than weapons.)La raà ­z de todos los males es el amor al dinero. The root of all evils is love toward money. (Love of money is the root of all evil.)A falta de pan, tortillas. Lack of bread, tortillas. (Make do with what you have. Half a loaf is better than none.)El amor es como el agua que no se seca. Love is like water that never evaporates. (True love lasts forever.)

WK 4 Essays

WK 4 Essays WK 4 Essay WK 4 Essay Question 1: Reliability pertains to the consistency of the measurement i.e. to have the same results each time under same conditions and same subjects under consideration. As reliability can not be calculated exactly each time so we estimate reliability. One type of this estimated reliability is Test-Retest Reliability i.e. to check to what extent a test will produce same result over a period or time. For example to test the â€Å"relationship between good neighborliness on health among Afro-American community of some selected New York ghettos† will be tested thrice over a period of over 2 years. Same measures will be emulated and administered thrice. The subjects and other correlative and variables will remain same and only hypotheses will tested again and again to check the reliability of the results. Reliability of measurements leads to the validity of the result i.e. strength of the conclusion(s). A test-pre-test reliability leads to Concurrent Validity i.e. a time-honored result of conclusion established after tests yielded same results each time. For example a clear relationship between good neighborliness and health is established with an adequate consistency level of .80 or greater. This .80 or greater level checked thrice lends validity to the conclusion. Question 2: Ethical Concern A: Human subjects under consideration must be informed of the experiment and must not be coerced to participate. This can lead to slight decrease in the reliability of the experiment and validity of the result to some extent as sampling will not remain same each time. If the quit level is too high then it can affect the reliability of the measurement too drastically. One way to address this ethical concern is that those subjects should be included in the sampling that could be willingly available next two times for test-retest. They should not have any relocation or any other objection on the experimentation during those two years. Ethical Concern B: Covert overt Research is another concern Research participants may change their behavior and modify their responses when they know that they are involved in experimentation. One way to overcome this concern is that participants should be informed of their participation in experimentation but must not be share the objectives and patterns of the research. Participant observation methods should be used for this purpose. Question 3: 1. Validity of the data collection instrument is in question as source of data in these articles is highly unreliable and it is not defined in concrete terms and no specifications are provided for this source of data. Source of data is Senator Clinton supporters in west Virginia but it is not clear whether this sampling represent whole west Virginia or a city. 2.  Opinion polls do follow the criterion for data collection as outlined for sociological research.   There source and sampling is not adequate enough to meet the necessities of sociological research. Mostly their sources are too wide and generic as they capture wider audience and groups. Their hypotheses are not properly formed and variable are not properly controlled. 3.  Reliability and validity can be checked to some extent. If readers are provided with the details of the instrument(s) utilized to collect the data. 4. Results presented by media reports and opinion polls do not undergo the reliability and validity tests. There is no test-pretest procedure over a period of time to lend concurrent validity to the conclusion. Furthermore, their results are molded by subjectivity i.e. personal biases and prejudices.

Postural Changes associated with Pregnancy Dissertation

Postural Changes associated with Pregnancy - Dissertation Example INTRODUCTION Posture is defined as the arrangement of body parts with reference to each other. Thus a good posture refers to the optimum alignment of musculoskeletal system so as to enable body movement with maximum efficiency (Britnell et al., 2005). Pregnancy brings about multiple changes in the women’s body affecting almost every biological system. While some of these changes go with pregnancy, others continue to affect for longer duration. There is an increase in body mass and dimensions with non-uniform distribution of both of these parameters. Thus the centre of gravity of the body and therefore, its equilibrium is disturbed and in order to regain it the body must lean backwards. The skeletal and muscular system of the women’s body undergoes several biomechanical changes to accommodate the growing uterus, maintain body balance and facilitate smooth delivery. Moreover the hormonal changes during pregnancy too affect the musculoskeletal system. Later weeks of pregna ncy are characterized by lordosis or a significantly increased curvature of the spine. Thus changes are observed in both the static and dynamic posture of the women during pregnancy. Along with these postural changes are observed discomforts such as low back pain which may or may not be associated with the postural changes. Moreover the postural changes have also been linked to increased vulnerability to fall incidences. Research has shown that the major postural adaptations associated with pregnancy include forward shift in centre of gravity, and subsequent anterior pelvic tilt, with some cases of lumbar lordosis and thoracic kyphosis. Approximately 75% of women exhibit a more posterior posture wherein the mass of the expanding uterus with the fetus is shifted posterior to the prior centre of gravity (Britnell et al., 2005). While pregnancy itself is associated with different levels of multiple discomforts both physical and mental, an understanding of the mechanism and nature of ch anges associated with pregnancy is imperative for developing measures to deal with these problems. This literature review aims to study the various aspects of postural changes associated with pregnancy. 2. PURPOSE Bipedalism is a distinguishing character of hominids and the human skeleton has developed several adaptations to enable it. One of the chief adaptations was an elongated lumbar region with both an increased length of individual vertebra and also increase in number of vertebra. Besides this, the lumbar vertebra are also arranged in a significantly concave curve, the feature being specifically termed as lumbar lordosis. As a consequence of lumbar lordosis the trunk’s centre of mass (COM) is shifted to a position above the hips thereby imparting stability to the upper part of body (Whitcome et al., 2007). The second major adaptation is sagittal pelvic tilt. Human posture and motion is thus defined by two biomechanical components responsible for imparting stability viz lumbar lordosis and sagittal pelvic tilt. However, pregnancy related marked changes in body shape and mass pose significant challenges to the bipedal stability (Whitcome et al.

Soul Man Movie Review Example | Topics and Well Written Essays - 500 words

Soul Man - Movie Review Example It goes to show the reality, things have changed for the better but racism still remains a daunting challenge and it affects the lives of the blacks' day in and day out. Racism is portrayed and also condoned in some shots of the movie thought it isn't conspicuous, this movie could only have been made in the late 1980s, it would have been severely condemned had it been made in the present time. Some shots are very offensive and raised a hue and cry back then but it was settled and did not become a great problem. The after-school format is also shown in the movie and it represents stereo-type, it goes to show how almost everyone does the same thing and the same represents stereo-typing in the society. The stereo-typing was focused upon to make the audience laugh and this, wavered the intention of the director. The intention was to make the people realize how stereotypical the society had become and to motivate the people to think out of the box but when it was turned into a comedy, the essence of it was lost and as a result of which the desired impact wasn't created on the minds of the people. Mark turned into a black man in order to