College essay writing service: September 2019

Monday, September 30, 2019

Dell Summary

Sunday, September 29, 2019

Cosmetic Dentistry

Cosmetic Dentistry This morning I woke up and looked in the mirror and noticed that my teeth were not as white as I like them to be. I think to myself, I need to call and make an appointment to get my teeth whitened with my dentist. Teeth whitening is an example of Cosmetic Dentistry. Cosmetic Dentistry is different than regular dentistry in the sense that regular dentistry deals with oral hygiene and the prevention, diagnosing and treating of any oral diseases. Cosmetic dentistry however focuses on improving a personÃ¢â‚¬â„¢s teeth, smile, and mouth. General dentistry deals with what needs to be done whereas Cosmetic dentistry is what you desire to be done. Cosmetic dentistry takes a lot of extra time and special training on the materials used. So therefore only dentists who are truly passionate about improving the teeth and smile take the time and extra money to do it. Cosmetic dentistry can also be used to restore a cavity. This is because cavities are mostly fixed by digging out the debris and filling them with a material. There used to only be gold, amalgam and other dark materials that left visible spots on the teeth. Now they have things like porcelain that are closer of a match to your tooth color. This makes it cosmetic dentistry because of the tooth color match. People tend to use porcelain or composite in fillings that they get and they even have their present fillings filled with these resins. In this essay I will go into detail about three different treatments of Cosmetic dentistry. I will explain to you first about how to fix a chipped tooth with dental bonding. Then I will explain to you how to improve that not so beautiful smile to an extraordinary smile by the use of veneers. And last but definitely not least I will explain to you about teeth whitening and the great effects. So sit back and get ready to enjoy learning about three amazing things we have in this world to make us look and feel amazing. DENTAL BONDING Your riding your bike for a nice trail ride but its starting to get dark and you donÃ¢â‚¬â„¢t notice the rock on the ground your about to hit. You Fly off your bike and hit your front teeth on the ground chipping both of your beautiful front teeth. How are you going to fix this? I have a solution. Dental bonding is a type of cosmetic dentistry that permanently attaches dental materials to the teeth by using adhesives and a special curing light. Dentists use tooth colored composite to restore chips or cracks. Also to fill cavities, close gaps between your teeth and repair worn down edges of your teeth. Dentists are the ones who do the direct composite bonding which means that the procedure is usually done in one dental visit. Dental bonding does not require any impressions or temporaries. First the dentist will place a plastic coating on the front of the teeth. Then they will place a bonding agent, colors it according to the color of your teeth, and shapes it. Then a light called the curing light is shined through the plastic that causes it to harden and makes the surface look shiny and polished. Then a thin layer of etch is placed on your teeth to make little fine holes in the enamel of your teeth. This is so the resin can stick to your teeth very well. Then many coats of composite resin are placed on your teeth and after each coat the curing light is used to harden that coat. Finally when the final cure is done, the tooth is sculpted to match the ones around it. The cost of dental bonding depends not only on the location, it can also depend on the bonding process and how small or big the procedure you had done was. The average cost of dental bonding is $300 to $600 dollars per tooth. Dental insurance sometimes covers the procedure depending on if it is used for structural purpose. LetÃ¢â‚¬â„¢s say that you are a ex-smoker, and after 5 to 10 years of smoking your teeth are just not as white as you like them to be. An easy fix for your tooth discoloration are Veneers. Veneers commonly known as porcelain veneers are thin sheets (half a mm thick or about as thick as a fingernail) of tooth colored porcelain that cover the front and sides of your teeth. They are used to fixed severe discoloration, chips, and cracks. They are also to help fix the gaps in your teeth. The placement of veneers usually takes two appointments. At the first appointment your tooth is prepared. The dentist does this by removing a thin layer of the surface of your tooth (about 0. 5 mm) so that the veneer can fit on the tooth. Next a gingival retraction cord is placed so that the dentist can get a good impression. Then an impression is taken so that the Lab Tech can create your veneers. Since your teeth feel rough after this preparation, the dentist will usually place temporary veneers. If he doesnÃ¢â‚¬â„¢t it is ok because they are not always needed. They are easier to stain while in this state though, so you should keep your teeth very clean. At the second appointment you will first have a try-on. The dentist will place a temporary bonding agent on your teeth and place the veneers on to see if the shape and color look good. If they do the dentist will then clean the veneers. A thin layer of acid etch is placed on the teeth to roughen the surface for a extra good hold. Then cement is placed on your teeth, followed by the veneer. Then the tooth is light cured and the cement dries and hardened within seconds. Finally the edges will be trimmed and the tooth will be polished. These veneers will provide you with a beautiful smile. Although veneers are amazing for smile improvement they are also a bit pricey. The type of veneers you get determines your price. Porcelain veneers are higher in price. They average at $925 to $2500 dollars per tooth but last for 15 to 20 years. Composite veneers average at about $250 to $1500 dollars per tooth, but only last 5 to 10 years. Dental insurance doesnÃ¢â‚¬â„¢t cover veneers. TEETH WHiTENiNG If your teeth are looking yellow and you just want them white, you could get teeth whitening. Teeth whitening is the most common cosmetic dentistry procedure there is. There are many forms of teeth whitening. You could do an hour under a light in the dental office or use one of the at home teeth whitening kits or even over the counter whitening solutions. They all have effects though some work better or faster. In the office dental whitening procedure they start by first protecting your gums with a rubber dam. Then they apply a high concentrated peroxide gel. After applying the gel they put you under a light for 15-20 intervals for up to an hour but no longer than that. People with very high amounts of staining may have to return for a second time. The average cost for an in office whitening is $650 dollars. The at home whitening that the dentist may send you home with a lower concentrated peroxide gel that is placed in a custom tray that fits your teeth. It is left on for an hour at least but sometimes the dentist will tell you to leave it on overnight. It has the greatest effects but takes longer to achieve the whiteness you want. The average cost of the professional take home kits average at $100 to $400 dollars. The last kind of teeth whitening I am going to tell you about is over the counter whitening kits. These kits have the same kind of gel that the professional take home kits have but it is at a even lower concentration. They also have one size fits all trays, strips, or paint on gel. This may only whiten the anterior teeth because they are not custom fit trays. The average cost of over the counter whitening is $15 to $100 dollars. I have taken you through three amazing cosmetic dentistry procedures. Although they may be pricey they all have payment plans. So if you have a chipped tooth, remember there is dental bonding to fix it. Or if you have a smile that you want to add some beauty to that there are veneers. And the most popular of all if you have some yellow teeth you want to get rid of, there is teeth whitening you can turn to. Cosmetic dentistry is an amazing thing we have to improve your teeth and smile with.

Friday, September 27, 2019

Pros and Cons of Teacher Websites Research Paper - 1

Pros and Cons of Teacher Websites - Research Paper Example Classroom websites have been recognized for their simple yet valuable contribution to the educational world, but not without a fair share of negative points. Either way, the users of this tool should evaluate whether these flaws outweigh the contribution that it makes to learning. The main function of a classroom website is to serve as an additional and convenient method for the teachers to share information with their students. From this, spring the many advantages of having a classroom website. The fact that it is a technology-based tool, however, has certain disadvantages. One large advantage of this is that teachers can always leave notes as reminders for the student on this website. The notes can be pertaining to any important matter discussed in class, which the teacher does not want the students to forget. This especially includes things like homework, announcements, and class rules. A student who cannot recall the homework assigned for a subject can simply log on to the website to see the reminder that the teacher left for the students. This however, requires the teacher to update the website after every single lesson (Greenspan, 2002). This can be a time-consuming activity, especially for teachers who have multiple classes to manage. Apart from this, the teacher may also use this website to make announcements and share news. This includes announcements such as informing the class of an upcoming fieldtrip or the cancellation of a class. The need for such announcements usually arises after class stands dismisses. Thus, if the teacher posts such announcements online, this saves the teacher the trouble of having to inform the students through other, lengthier means, and it also ensures that the news is displayed.

Creation vs Evolution Research Paper Example | Topics and Well Written Essays - 1500 words

Creation vs Evolution - Research Paper Example Ultimately, even those in State of Kansas which has decided to teach both, all of society will accept that there is no debate but it will likely be a long time in coming because society itself evolves very slowly. The teaching of creation in public schools simply fulfills the purpose of protecting specific underling religious beliefs. If creation is to be taught, it is solely the responsibility of parents and the church because teaching the religious theories of creation in schools not only violates constitutional precepts. This issue invokes intense passions from those driven by their religious faith and those who would stand up for the Constitution and those that gave the lives of their loved ones to protect it. The First Amendment begins with Ã¢â‚¬Å"Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereofÃ¢â‚¬ ¦Ã¢â‚¬ (Ã¢â‚¬Å"The ConstitutionÃ¢â‚¬ ) The idea of creation is undeniably religious doctrine. The government, therefore, cannot promote it in classrooms as science without infringing on the First Amendment. The Supreme Court has held that instructors may not teach that humans were created by God and must present only scientific e xplanations for the history of life. Creationism can not be presented as scientific fact. In addition, it is also unconstitutional to compel teachers to teach creationism and schools may not refuse to teach evolution in an effort to avoid offending religious individuals. The idea of disclaimers placed in school books such as Ã¢â‚¬Ëœthe teaching of evolution is not intended to influence or dissuade the Biblical version of Creation or any other conceptÃ¢â‚¬â„¢ has been lawfully established to be unconstitutional (Ã¢â‚¬Å"FreilerÃ¢â‚¬ , 2000). An instructor also has the constructional right to teach evolution (Ã¢â‚¬Å"Epperson v. ArkansasÃ¢â‚¬ , 1968). Religious theories of creation may be incorporated into school

Thursday, September 26, 2019

Service management marketing Case Study Example | Topics and Well Written Essays - 3750 words

Service management marketing - Case Study Example The nature of the relationship between each service-oriented facility and the end consumer is based on separate transactions that can occur continuously, that is, a client can buy or sell an item through EBay and Amazon at any time, but each physical sales transaction is a singular event. The benefits of EBay and Amazon to sellers are global recognition and ease of use. Each service allows any retailer or private party to advertise their product via the Internet, and so each product has the potential of reaching millions of viewers internationally. The service encounter is fairly well-received, although due to the direct nature, a person may experience difficulties with a particular seller or buyer. The service facilities of both EBay and Amazon are Internet based E-commerce. Service interaction is mainly the computer interface, although this can also be done by cellular phone, PDA, and any other medium of connecting to the Internet. The role of customers in EBay and Amazon is highly imperative to the service. Each customer can be defined as a buyer or seller of a product, and in turn these people can review and leave feedback for interactions of other buyers and sellers of products. Direct contact with EBay and Amazon is rare in the person to person domain; however, both companies have continuous updates, newsletters, service additions, and so forth that are centered on improving the customer experience. The concern is that these communications are largely one-way, contact with EBay and Amazon disseminates from EBay or Amazon, and not from the customer. Demand for EBay services is high. Recently, Bob Swan CFO of EBay announced at the at Merrill Lynch Internet, Software & Services Conference that: the biggest piece of it [EBay] is the large and growing core business, or the eBay platform. With a global presence in 33 markets, transacting $1,800 of goods per day, with over -- I'm sorry -- per second -- with over 6.6 million new listings added per day, and 45,000 developers leveraging our APIs, we've grown from over 222 million users on this site as we exit 2006. And we've processed $52 billion of global merchandise value on the site during the course of 2006, as a whole (Fair Disclosure Wire pp 7 2007). Amazon has similar consumer demand structure, with 9.7 billion dollars in annual revenue, but where EBay applies a global presents, multi-functional consumerism and value strategy, Amazon appeals to the customer services and their capabilities, according to Adam Selipsky, vice president, product management and developer relations, Amazon.com Inc: "As with most good ideas, we come at things from two different directions: What do people need, and what can we do well" says Selipsky. "We look internally and ask, 'what do we have built, or what can we build with our world-class engineering talent that would justify creating a business"' (Cone p 51 2007).

Wednesday, September 25, 2019

Child abuse and the catholic curch Research Paper

Child abuse and the catholic curch - Research Paper Example question in most peopleÃ¢â‚¬â„¢s minds is how such inexplicable and copious numbers of abuse could go unnoticed, unreported, unacknowledged and with no accountability for so long. The question posed within this essay however, is why? Why has there been such wide spread and proliferate sexual abuse of children within the Roman Catholic Church. Gauthe, who was a priest based in Louisiana was shifted from parish to parish by church elders and authorities once they became aware of his abusive activities. In an attempt to maintain equilibrium within the Church and keep control of the situation themselves the Church gave Gauthe opportunity to continue his sexual abuse against minors. Due to the media and public outcry however, he was brought to trial and removed from his position in 1983; in 1985 he was sentenced to jail for twenty years but was released after ten; whereupon he was later arrested again for further accounts of molesting young boys (Gavrielides & Coker, 2005; Werth, 2003; Dale & Alpert, 2007). The Gauthe case however proved to be the first wave in a tumultuous ocean of abuse, molestation and cover-up in the Catholic Church. In 2002 the Boston Globe (January 6) declared that the Ã¢â‚¬Å"Church Allowed Abuse by Priests for YearsÃ¢â‚¬ (Carroll, 2002; Isely, Isely, Freiburger & McMackin, 2008). The story revealed how Law, the archbishop of Boston and his forerunners had turned a blind eye to sexual abuse and had permitted their priests to abuse children without retribution (Carroll, 2002), and that priests like Father Geoghan, who had purportedly raped or molested 130 children had been protected by the Church (Carroll, 2002). Such revelations instigated a plethora of victims coming forward to report abuse, and the media using words such as Ã¢â‚¬ËœcrisisÃ¢â‚¬â„¢ and Ã¢â‚¬ËœscandalÃ¢â‚¬â„¢ in relation to the Church (Plante, 2004), incited public outcry and demand for answers and retribution. The outcome was the realization that nobody was in reality, aware of the enormity of the crisis,

Tuesday, September 24, 2019

Leadership management Research Paper Example | Topics and Well Written Essays - 3000 words

Leadership management - Research Paper Example The research is aimed at evaluating and understanding the leadership management practices in a selected organization which is the Tige Restaurant located in Wellington. The research is introduced by identifying the scopes of the research work with a consideration of the literary works done on similar topics till date. This is followed by the formulation of the research questions and research objectives. Suitable research methodologies which would be used to collect, analyse and interpret data are identified and explained wherein the importance of qualitative data collection through the use of questionnaire and sampling is identified to be relevant to the study. The collected data are analysed and interpreted and the findings are documented to reach to a suitable conclusion for the study. The report is concluded with the provision of relevant recommendations which can be used by the management of the chosen organization. The research paper is prepared on the topic of leadership management and leadership communication of Tige restaurant. The restaurant is a well-known Chinese restaurant situated in Wellington. The research is conducted with the aim of evaluating the leadership styles, leadership communication leadership practices and the overall leadership management in the Tige restaurant. The research is likely to be an important asset in the literary works of leadership management and leadership communication. Leadership communication and management has evolved as critical factors for the success of business organizations across the globe. As such, the study on this topic is expected to add value to the research works done in this field. The main objectives of the research are to evaluate the existing leadership principles and leadership management practices as followed in the chosen company which is the Tige restaurant. The research would take into consideration the aspects of leadership management, leadership styles, leadership

Monday, September 23, 2019

Auxiliary Aircraft Systems Article Example | Topics and Well Written Essays - 250 words

Auxiliary Aircraft Systems - Article Example Every fuel tank has to withstand vibrations, fluid, structural, and, inertia loads without failure. In addition, fuel systems have to be free from vapor lock that occurs when fuel is used at its critical temperature. The danger of fuel starvation, fire, or explosion in flight makes it compulsory for fuel system irregularities check top priority. An aircraft fuel system has to deliver and store clean fuel at flow rate and pressure that sustains operations. Therefore, any evidence of leak or malfunction has to be rectified before departure. Personnel maintaining fuel or handling fuel systems should be trained on best practices that reduce incidents or accidents. Conditions of fuel trucks and storage tanks should be monitored to avoid contamination. Filter treatments and changes are to be carried regularly. Samples from all drains must be inspected regularly. Fueling and defueling of an aircraft should be done outside to avoid fuel vapors that might accumulate in hangar and cause an accident; these processes require fire extinguishers. Personnel should wear clothing that does not promote static electricity buildup. Correct fuel should be put in the aircraft by the placing placards at the filling port or at the fueling station. Nozzles are required to be clean every time to avoid contamination of the fuel. When defueling, if a tank is drained due to fuel contamination or suspected contamination, then it should not be mixed with other

Sunday, September 22, 2019

Cognitive component Essay Example for Free

Cognitive component Essay The cognitive component of SWB involves making judgments of oneÃ¢â‚¬â„¢s life: either satisfaction with life as a whole, or satisfaction with life domains such as work, family, leisure, health, and finances (Prince, Prince 2001; Diener et al. , 1999). It can be viewed as how you think about your life (in contrast to the affective component: how you feel about your life). In this study, the cognitive component means the way the elderly perceive, think and assess their life and their beliefs and attitude toward life, world and God. Campbell (1976) suggested that individuals judge their objective situation in each of various life domains according to standards of comparison based on aspiration, expectations, feelings of what would be just, reference group comparisons, personal needs, and personal values. Domain-satisfaction provides useful information about with which aspects of life an individual may be happy or unhappy, but cannot be summed to give an overall impression of life satisfaction. This would mean that it is necessary to assess overall satisfaction with life, as well as life domains (Susan Hird, 2003). An idea that has long captivated writers is that how we perceive and think about the world determines our SWB. In the area of SWB, researchers find that one can dampen or amplify oneÃ¢â‚¬â„¢s emotions by what one thinks, and thereby experience more or less intense emotions (Larsen, Diener, Croponzano, 1987). This approach relies on the standards of the individual to determine what is the good life and the personal choices the person make at the moment (Diener, 1984). People might increase their SWB by control of their thoughts. For example, perhaps SWB can be increased by believing in a larger meaning or force in the universe. Support for this proposition comes from findings showing that on average religious people are happier than nonreligious people (e. g. , Ellison, 1983; Myers, 1992, cited in Diener et al. , 1997). The study explored how the elderly think about their life or what thought processes, beliefs and attitudes predominantly helped the elderly to experience a sense of well-being at this point of their lives. Affective Components (Affect Balance) It is the second component or construct of SWB, which corresponds to what we generally understand as happiness. According to (Prince, Prince 2001) affect is thought of as how happy or unhappy you are. It results from a balance between positive affect and negative affect (Christopher, 1999). As it has been already indicated, when we appraise how much we appreciate the life we live, we estimate our typical affective experience to assess how well we feel generally, which is referred to here in the study as affective component. In summary, the affective component can be thought of as how you feel about your life (Susan Hird, 2003). Suh Diener (1997) observed that feeling pleasant emotions most of the time and infrequently experiencing unpleasant emotions, even if the pleasant emotions are only mild, is sufficient for high reports of happiness. Although people report being above neutral in mood the majority of the time (Diener Diener, 1995), intense positive moments are rare even among the happiest individuals. Instead happy people report mild-to-moderate pleasant emotions most of the time when alone or with others and when working or at leisure. One thing is clear, that people need to understand that intense experiences are not the corer stone of a happy life (Diener, 2000). Mood and emotions are called Ã¢â‚¬ËœaffectÃ¢â‚¬â„¢, and there is contradictory evidence as to whether Ã¢â‚¬Ëœpleasant affectÃ¢â‚¬â„¢ and Ã¢â‚¬Ëœunpleasant affectÃ¢â‚¬â„¢ form two independent factors and should be measured separately, or whether they are interdependent (Diener et al. , 1999). The amount of difference between momentary pleasant and unpleasant affect is still debated, but the separability of long-term affective dimensions is less controversial. Diener and Emmons (1984) found that unpleasant and pleasant affect become increasingly separate as the time frame is increased (Diener et al. , 1999). In the case of the institutionalized elderly, the study examined the affective component in general, mainly how they felt generally about their lives that helped them experiencing a sense of well-being in their lives. As indicated by Christopher (1999), it is this second aspect of SWB that corresponds to what we generally understand as happiness and it results from a balance between positive affect and negative affect.

Saturday, September 21, 2019

Burkitt Lymphoma Essay Example for Free

Burkitt Lymphoma Essay Burkitt Lymphoma was mapped out in geographic distribution across Africa by Dr. Denis Parsons Burkitt (Huang 2005). This disease is a high grade B-cell neoplasm, which has two major forms: the endemic (i. e. African nature) and the non-endemic (i. e. sporadic nature). Burkitt Lymphoma is mainly found as childhood tumor, yet it is, also, observed in adult patients (Huang 2005). This Lymphoma type is one of the fastest growing malignancies in humans, and it has a high growth fraction (Huang 2005). Burkitt Lymphoma is a monoclonal proliferation of B lymphocytes that is characterized by small non-cleaved cells is appeared to be uniform in appearance (Huang 2005). It produces a diffuse pattern of tissue involvement. While under the microscope, this lymphoma is characterized by the presence of a Ã¢â‚¬Å"starry skyÃ¢â‚¬ appearance due to scattered macrophages with phagocyte cell debris; this is observed in other highly proliferate lymphomas, as well (Huang 2005). The African form of this lymphoma most often involves the maxilla or mandible and the involvement of abdominal organs, for instance the kidneys, ovaries, and retroperitoneal structures, but is somewhat less common (Huang 2005). On the contrary, the sporadic form involves the abdominal organs: distal ileum, cecum, and mesentery. The involvement of pelvic organs or facial bones is rare (Huang 2005). The majority of Burkitt Lymphomas carry a translation of the c-myc oncogene from chromosome eight to the immunoglobulin (lg) heavy-chain region on chromosome fourteen (t 8;14)or a light-chain loci chromosome two (t 8;2)or chromosome twenty-two (t 8;22) (Huang 2005). Within the African form of Burkitt Lymphoma, The Epstein-Barr virus (EBV) has been implicated strongly and the relationship in the sporadic form is less clear (Huang 2005). Epstein-Barr virus is associated in approximately twenty percent of sporadic cases. The rare cases in adult are usually associated with immunodeficiency, predominantly AIDS, respectively (Huang 2005). Some have reasoned, the host is unable to generate adequate T-lymphocyte response or Epstein-Barr specific cytoxic T-cells (Huang 2005). This subsequently results in excessive B cell proliferation. The lymphocytes have receptors especially for the Epstein-Barr virus and are the specific targets (Huang 2005). In the African form, the hosts are believed to be unable to increase a suitable immune response to primary Epstein-Barr infection. This is possible due to coexistent malaria or other infections that are immunosuppressive, also (Huang 2005). Burkitt Lymphoma is an extremely rare cancer in the United States, with only 100 new cases each year. However, Burkitt Lymphoma is endemic in many regions of equatorial Africa and other tropical regions between latitudes 10Ã‚ ° south and 10Ã‚ ° north. The frequency of this cancer in these endemic regions is 100 per million children (Huang 2005). The male-to-female ratio is 2-3:1, and the most common a in children is seven years of age is the mean in African, eleven years of age is the current mean outside of Africa (Huang 2005). Prior to aggressive therapeutic treatment program, children with Burkitt Lymphoma died rapidly. However, with a combination of chemotherapy and CNS prophylaxis the survival rate has increase to at least sixty percent; and patients with a limited disease now have a ninety percent chance of survival (Huang 2005). Patients with bone marrow and CNS involvement have a poor prognosis. Adults with the disease, especially those in the advanced stage, do more poorly than affected children (Huang 2005). In the African form, patients most often present swelling of the mandible and other facial bone with the loosening of teeth, and swelling of the lymph nodes, which have rapid growth below the mandible (Huang 2005). Patients who have the sporadic form are commonly presented with abdominal tumors that cause swelling and pain in the affected area; few patients have symptoms of bowel obstruction that is caused by tumor growth (Huang 2005). Burkitt tumors growth is tremendously rapid in nature, and patients have evident metabolic derangement and renal function impairment and may include epidural mass, skin nodules, central nervous system symptoms, and bone marrow involvement (Huang 2005). Rare cases of Burkitt lymphoma can present acute leukemia with fever, anemia, bleeding, and adenopathy (Huang 2005). Foremost indicators of Burkitt Lymphoma include soft tissue mass associated with involvement of the mandible, enlarged cervical lymph nodes, abdominal masses, and ascites (Huang 2005). Moreover, the exact cause and mechanisms of this lymphoma are presently unknown. It is important that Burkitt Lymphoma is distinguished from other abdominal tumors in childhood, such as Wilms tumor, neuroblastoma, and peripheral neuroectodermal tumor (Huang 2005). Also, within the bone marrow, B and T precursors and myeloid leukemia must be distinguished (Huang 2005). Systemic chemotherapy is the treatment for this lymphoma is all its stages. The survival rate ultimately depends on the stage at initial diagnosis (Huang 2005). Patients with a localized infection respond well to chemotherapy, with an excellent rate of survival. Cyclophosphamide therapy has been curative for eighty percent of children in Africa with the early stage of Burkitt Lymphoma (Brock 1996). The effect of cyclophosphamide is due to its metabolite phosphoramide mustard (Brock 1996). The metabolite is only formed in cells which have low levels of aldehyde dehydrogenase. The Phosphoramide mustard forms DNA cross links between and within DNA strands this leads to cell death (Brock 1996). However, combination chemotherapy has improved treatment results. Intensive, short-duration, alkylator-based regimens are necessary for all patients with the sporadic form (Huang 2005). In patients with AIDS, Burkitt Lymphoma is in advanced stage at time of diganosis and tends to involve extranodal sites (Huang 2005). Furthermore, because of underlying immunodeficiency and leukopenia, these patients tolerate systemic chemotherapy very poorly. A patientÃ¢â‚¬â„¢s expiration usually follows shortly after diagnosis (Huang 2005). A nine week regiment of cyclophosphamide, doxorubicin, vincristine, and prednisone was effective for early stages of the disease and a longer regimen included a combination with radiation (Link et al. 1997). The cure rate more than exceeded ninety percent with minimal toxicity. Therefore, a lesser-intensive therapy is under evaluation as a potentially effective means to steer clear of unnecessary toxicity for patients with early stages (Link et al. 1997). This may achieve similar cure rates obtained with prolonged treatment (Link et al. 1997). Vanderbilt Medical Center has reported results for patients with poor-prognosis non-Hodgkin Lymphoma, which includes Burkitt Lymphoma, using a high dose and short-duration combined chemotherapy comprising cyclophosphamide, etoposide, doxorubicin, vincristine, bleomycin, methotrexate with leucovorin rescue, prednisone (Huang 2005). Burkitt Lymphoma patients have a high risk of tumor lysis syndrome before chemotherapy is started because of rapid tumor cell turnover (Huang 2005). This is a life-threatening situation and should be anticipated and addressed to the patient prior to beginning treatment (Huang 2005). Treatment should be preformed at a proper facility with renal dialysis is available, predominantly for patients with progression of disease (Huang 2005). Treatment of recurrent Burkitt lymphoma is difficult. Bone marrow transplantation is the only hope of long-term survival for these patients (Huang 2005). Burkitt Lymphoma is a high grade B-cell neoplasm, which is highly endemic in Central Africa and sporadic throughout other countries (Huang 2005). This disease is the fastest growing malignancy in children. A combination chemotherapy is the most effect mode of treatment and has high cure rates within early stages, and the moderate cure rates for progressed patients (Huang 2005). References Brock N. (1996). The history of the oxazaphosphorine cytostatics. Cancer. 78:542-7. Link MP, Shuster JJ, Donaldson SS, et al. (1997). Treatment of children and young adults with early-stage non-Hodgkins lymphoma. New England Journal of Medicine. 30 October 1997; 337(18): 1259-66. Huang, H, MD, PhD et al.. (2005). Burkitt Lymphoma. eMedicine. Date visited 19 April 2006. http://www. emedicine. com/med/topic256. htm

Friday, September 20, 2019

The Advantages Of Using DFIG

The Advantages Of Using DFIG In addition to its stator, the DFIGs rotor is also connected to the grid using a power converter (Picture 3). This type is very common for wind turbines as it offers certain advantages compared to other types: It can operate like a synchronous generator and at variable speed, although its stator is directly connected to the grid. The converter can adequately control the voltage (phase and magnitude) that is applied to the rotor and as a consequence control the magnetic fields frequency or speed. It actually forms an AC excitation with a variable frequency, just like the DC excitation used in synchronous generators. This operation gives the DFIG the benefits of a synchronous generator. These benefits include the separate control of reactive and active power, or the control of the wind turbines power factor. The DFIG wind turbines are better than other designs in terms of grid compatibility. It can operate at variable speed, sub- or super synchronously. The optimum speed can be chosen by adjusting the frequency and phase of the voltage that is applied to the rotor, and is such that maximum power is obtained by the wind, in different wind speeds. Since it can operate as synchronous generator, a major advantage of large DFIG wind turbines is that they can contribute to the systems stability after a fault occurs. However, this relies heavily on the control options given by the power converter. Moreover, A DFIG wind turbine can generate reactive power even when the mechanical part is not operating and in not delivering active power. Relative to other variable speed generators, DFIGs power converter is rated at lower power (i.e. about 30% of the wind turbines rated power), since only part of the total power delivered by the wind turbine is transferred through the converter. This makes the wind turbine cheaper and lighter. The power mentioned above, can be either delivered by the rotor (when the turbine rotates with a higher than the synchronous speed), or absorbed (when its speed is below the sync speed). This double mode gives the DFIG the ability to operate at speeds below or above even by 50% of the sync speed, although actually lower variations are chosen. Compared to other generators with variable speed, which use external rotor resistances to allow variable speed, DFIG are more energy efficient, since there is little power dissipated in the converter. DFIG can be accurately controlled due to the fact that the power converter can adjust both the magnitude and phase of the voltage applied to the rotor. This attribute, combined with pitch-control in wind turbines offers the operator more accurate power control, especially in high winds where high power output can cause severe damage to the equipment. Finally DFIG shares the benefits of synchronous and inductive generators regarding its contribution to power systems stability. Appropriate control can improve the damping of power variations in the system, without compromising voltage control. +voltage control Picture 1 Active Management in the distribution network [4], [5], [6] The dispersed nature of renewable resources necessitates their connection at the distribution network, which was designed in order to convey power from high to low voltage. Now, with the introduction of renewable electricity sources, the power can follow any direction, affecting the power and voltage quality as well as the security of the system. Therefore considerable amounts of money should be spent for their upgrade, if the optimum renewable potential is to be achieved. Another, less expensive approach is the transition from the networks traditional passive operation to their active management. Under active management approach, new control and communication technologies are incorporated into the system and allow the operator to control in real time the voltage, the power flows and even the fault levels. The main options under active management are: Power flow management The risks regarding the network power flows must be sufficiently eliminated. The possibility of the distributed generators to deliver power above the systems ratings-capacity can significantly threat the systems operation. This is a serious issue, especially in case of a circuit outage. The power flow management protects the systems parts taking into account their nominal capacity. Voltage control The voltage at a bus is affected by the real and reactive power on that bus as well as the R and X values of the line. The voltage change at that bus is approximately equal to. The most significant issue accruing from the introduction of distributed generators at the distribution networks is the voltage rise at the connected bus. The operator can choose appropriate R and X values but this would require an expensive network upgrade. The control of P and Q is a less expensive option, and this is why it is preferred. The main actions usually taken are: On-load transformer tapping: The operator might reduce/increase the voltage at the primary substation reducing/increasing all the subsequent voltages. Nevertheless, in case of reducing the voltage, a possible generator disconnection might drive the voltage below its allowable limit. Power factor or/and voltage control: see question 4 Reactive power compensation: Appropriate devices (capacitor banks, STACOM etc) can be connected on critical buses, so that they deliver/absorb reactive power and fix the voltage profile. Generation curtailment: another way to mitigate a voltage rise, would be to curtail real power generation from the distributed generators. However, this sets a significant constraint in the renewable energy that can be exploited. Fault level management : see below Load management Reducing or shifting adjustable loads can alleviate the pressure on the networks operation, especially in case of very low renewable generation. Power quality management The operator exploits various capabilities at the generators, loads or other special devices to maintain the powers high quality in terms of harmonics, voltage disturbances etc. Power Factor vs Voltage Control [7], [8], [9] The dominant negative impact of connecting generators in the distribution network is the distortion of the voltage profile. The simplest, but at the same time the most expensive, solution for this problem is the upgrade of the local grid. However, there are more efficient ways, (borrowed by the operation of the transmission networks) that could allow for larger DG penetration without big distortions at the voltage profile. Two of them, concerning the generators operation, are: Power factor control: the generator operates at a constant power factor. The reactive follows the real power output so that their ratio remains constant. This kind of operation was required by the distribution network operator (DNO) in the context of the fit and forget rationale, with which all the low voltage networks were initially designed. The major advantage of this method is that it does not disrupt the operation of other regulation devices, such as OLTC. However, it may have a negative impact on the voltage at the connected bus, since it tends to contribute to the voltage variation which is influenced by the changes in power flows. As a consequence, this approach limits the total generation capacity that can be connected on the network. Voltage control: the generator adjusts its reactive power output so that the voltage at the connection bus remains within the allowable limits. This adjustment is done according to the real power output and the voltage drop or rise occurring at the bus. Obviously, the generators power factor is not constant anymore, although an upper and a lower limit would normally apply. The DNO are not very keen on allowing generators to operate in that way, since this operation could considerably affect the operation of other voltage regulation devices, such as OLTC transformers. Moreover, if a small generator tries to correct a high voltage change, it might need to set its reactive power output at a critical high or low level. This sort of dangerous operation close to the thermal or overcurrent limits entails a significant increase in the maintenance cost, or even worse, it can activate the protections and cause a sudden trip. A combination of the two approaches described above is considered the best solution regarding the optimum operation of a distributed generator. The main idea is that the generator operates with a constant power factor until the point where the voltage at the connected bus reaches the upper or lower allowable limit. At this point, the power factor control is deactivated, letting the generator to adjust its reactive power output and fix the voltage. Again, the power factor must be kept within its the allowable limits. When the voltage returns within its limits, the power factor control is reactivated. The consequences of new DG capacity on network fault levels and protection [4] The connection of distributed generation, using either synchronous or inductive generators, causes an increase in the systems fault levels, owing to the additional generation that could feed a potential fault current. This is especially the case at the very edges and weak parts of the distribution network, where the renewable generators are usually connected. The new fault levels might exceed the rating of the existing protections. Such an implication could cause significant damage to the protection equipment and set the systems security at high risk or ultimately incur supply interruptions. But most importantly could set personnels life in to severe danger. Therefore, every time a new distributed generator is connected, the fault levels must be re-examined and wherever is deemed necessary, protections must be upgraded. In some cases it might be necessary to upgrade the respective part of the network (reduce the R and X values new lines or/and transformers), which would usually requ ire significant amount of money. Nonetheless, in the context of the active management operation of the distribution network, the operator can take some alternative measures: Advanced converter technology: the use of advanced power inverters, makes a generators contribution to the fault current much lower. The more advanced a converter, the higher its cost. Network reconfiguration: changing the topology of the network could change the fault level at some buses. This operation is already available in most of the networks for maintenance purposes. Is Limiter: a device that can instantly increase the systems impedance (lower fault level) in case of an incident, but it needs replacement after each use. Sequential switching: the contribution at the fault current by one or a team of distributed generators can be isolated in case of a fault in a different section. The need for active power balancing in networks with high penetration of renewable energy resources In order for the frequency of a system to be maintained, the total real power generation must always be equal to the total real power load and losses. A distortion of this balance could cause a frequency deviation beyond the allowable limits and hence, damage the equipment and the loads. Therefore, it is of major importance that the system operator must always retain the active power balance. Most of the prevailing renewable energy resources, such as wind or solar, have an intermittent behaviour and their output relies on the weather/climate conditions and hence, cannot be controlled. Although there were significant advances in the weather forecasting, errors are still present. Moreover, any sudden incidents that could trip a big part of the total generation (not only renewable) could also contribute to a real power unbalance. Adding to this the fact that the demand can also vary, the large penetration of renewable resources increases considerably the risk for the systems stability. The main techniques that a system operator can use in order to maintain the power balance are: Storage: Large (compressed air, hydro-pump storage, flywheels etc) or smaller (EV etc) storage facilities can contribute to the real power balancing. They can store energy when the renewable generation exceeds the total load and deliver it back to the network when the total generation is not sufficient to meet the demand. Some storage technologies are better than others in terms of their performance, however all of them are quite capable of quickly adjusting their output to support the systems frequency. Nonetheless, most of the storage technologies are still very expensive. Pump storage, a cheaper option, is naturally constrained, while the massive introduction of EV is not feasible in the foreseeable future. Demand Side Management: The active power equation has two sides. Available for adjusting or shifting demand could adequately contribute to the systems stability when the renewable sources are lower than expected, if appropriate incentives are given to the consumers. Dispatchable units: The unbalances risk that might emerge by the large penetration of renewable energy resources could be offset by large and fast, in terms of start-up and output, generating units, such as hydro or gas plants. However, hydro plants are naturally constrained and gas power plants are still causing carbon emissions, albeit fewer than the coal generators. Interconnections: Interconnections between large electricity grids could significantly reduce the risk associated with the large penetration of renewable energy sources. Each system could either absorb or deliver real power from its counterpart depending on its total generation and demand. DC interconnections are more common, since they can transfer more real power and isolate the two systems in terms of frequency control, although they are more expensive than conventional AC interconnections.

Thursday, September 19, 2019

Essay --

RESEARCH PROPOSAL ASSESSMENT OF CNR 9 COMMUNICATION SYSTEM COURSE IN ROYAL SIGNAL REGIMENT INTRODUCTION 1. Military organization was the unique entity which is self-contained organization with the complete equipmentÃ¢â‚¬â„¢s for their vision and mission. For the purpose of the training and operation, one of essential part was the communication system. The communication system which belongs to any organization will become their core competencies once they are valuable, costly to imitate, rare and non-substitutable. Communication system provides the ability to mass combat power. It is a way of architecting a battle or a campaign. It is a calculated to create possibilities for future force utilization. Effective communications determines how, when and where the force fight in a theater, where and when combat power can be massed. Ã¢â‚¬Å"Without the communication I only can command my tableÃ¢â‚¬ is an expression attributed by Mc Arthur. Most importantly, the effectiveness of communication at the operational level is a part of the concept of operations. 2. As indicated in the Army Transformation Plan 2012, communication plays an important and significant role in ensuring that the army shall be a credible and versatile objective force that will be able to operate in a multi spectrum environment. CNR 9 communication system was procured last 6 year into the army inventory. More than 6000 radio set been purchased and it is consisting of HF(High Frequency) and VHF(Very High Frequency) which is fully digitized. The HF radio also known as SKY FAST and FAST NET for the VHF. The company that delivered the systems is Sapura Sdn Bhd which a local company and Thales, France is responsible to produce the product inclusive the training toward the users. Thales... ... assigned to take charge in conducting, distributing and collecting back the questionnaires. Besides that, secondary data was also collected through interviews with key management personnel of IKED as well as the SAPURA Sdn Bhd. Some information also gathered from magazines, academic journals, published books and internet sources in the area of radio communication courses and syllabus. DATA ANALYSIS TECHNIQUES 20. For the purpose of this research, the data obtained is analyzed using the Ã¢â‚¬Å"Statistical Package for Social ScienceÃ¢â‚¬ SPSS version 22.0 software. The techniques of data analysis consist of descriptive and inferential analysis. Descriptive analysis covers analysis on the frequency of the respondentsÃ¢â‚¬â„¢ respond and the interaction relationship between independent and dependent variable in this research; whereas, inferential analysis includes t-test and ANOVA.

Wednesday, September 18, 2019

Abraham Lincoln :: essays research papers

Abraham Lincoln was born Feb. 12, 1809, in Hardin County, Kentucky. His parents were both born in Virginia. his mother, who died when he was ten years old, of a family of the name of Hanks. His father. Who moved from Kentucky to Indiana when he was eight years old. He said Ã¢â‚¬Å"It was a wild region, with many bears and other wild animals still in the woods. There I grew up.... Of course when I came of age I did not know much. Still somehow, I could read, write, and cipher ... but that was all." Lincoln made extraordinary efforts to attain knowledge while working on a farm, splitting rails for fences, and keeping a store at New Salem, Illinois. He was a captain in the Black Hawk War, spent eight years in the Illinois legislature, and rode the circuit of courts for many years. His law partner said of him, "His ambition was a little engine that knew no rest." He married Mary Todd, they had four children togather, only one of them lived to maturity, the rest died at an early age. In 1858 Lincoln ran against Stephen A. Douglas for Senator. He lost the election, but in debating with Douglas he gained a national reputation that won him the Republican nomination for President in 1860. As President, he built the Republican Party into a strong national organization. Further, he rallied most of the northern Democrats to the Union cause. On January 1, 1863, he issued the Emancipation Proclamation freed the slaves within the Confederacy. Lincoln never let the world forget that the Civil War involved an even larger issue. This he stated most movingly in dedicating the military cemetery at Gettysburg: "that we here highly resolve that these dead shall not have died in vain--that this nation, under God, shall have a new birth of freedom--and that government of the people, by the people, for the people, shall not perish from the earth.