America and Nuclear Weapons Testing essays

America and Nuclear Weapons Testing essays American policymakers in the late 1940s debated the very controversial topic of nuclear weapons testing on American soil. Previously, American policymakers such as Atomic Energy Commission (AEC) head Sumner Pike stated that "only a national emergency could justify testing in the United States" (Ball 27-28). As the Soviet Union and communism expanded half a world away, hostilities broke out in Korea, which authorities asserted was a national emergency that would warrant nuclear testing on American soil. Authorities within the AEC believed that to maintain nuclear superiority and preserve national security, nuclear tests would have to be conducted in the continental United States. The Nevada Test Site (NTS) was chosen for a few primary reasons: it was a flat area with little rainfall to minimize radioactive fallout, the winds traditionally blew east towards the relatively "uninhabited" portions of Nevada and Utah and away from the heavy population concentrations of the West Coast (Che ney 36). Nuclear weapons' testing was essential for national security, yet it was not necessary for these tests to take place within the continental United States. Testing at the Nevada Test Site began in early 1951, and within the next seven years, 90 nuclear explosions occurred in the Nevada desert. The ominous result of these tests was the distribution of radioactive particles throughout the United States with areas in eastern Nevada and southern Utah especially affected (Some Questions 1). The tests were conducted to enhance the American nuclear arsenal – the goal wasn't only to achieve the biggest bomb, it included the development of tactical nuclear devices that could be used on the battlefield against enemy troops without causing harm to friendly troops. As Glenn Cheney, a radioactivity researcher and author, comments on the nuclear arms race between the United States and the Soviet Union, "To fall behind, to become weaker, might be to practical...

General Educations Writing Essay Example

General Educations Writing Essay Example General Educations Writing Essay General Educations Writing Essay Written Communications is one of my weaknesses because I have a hard time learning how to compose works that apply the correct structures of a composition which Is coherent paragraphing, Intelligible sentence structure, precise and varied word choice, and correcting spelling, grammar, and mechanics. I have always have problems In this area in school because I didnt know express myself clear In my written and If it was a boring topic It was hard for me to write about because It was meeting that was not interesting to me. I plan to work on this area In the future by asking my teachers for help and guidance with my writing. This will Impact my success In college because I would be able to analyze and Interpret college level materials without any Issues. Oral communicating would be the second weaknesses because I have a hard time learning how to understand information in different verbal and nonverbal messages. Again this was something I struggled with as a child because I didnt like doing presentation in front my class so I would not do it because I was shy to speak in front of people and felt like it was putting on the spot light. I plan to work on this area in the future by noting letting my pride get in the way of me doing what I got to do when comes to doing presentations in front of people. This will impact my success in college I will be more confident to do my work. : Last area I would consider a weakness would be Critical Thinking and Problem Solving because I dont use appropriate problem solving method when I get mad. It is hard for me to control my anger and deal with certain situation professional. So what I have learned to go is Just walk away I find that to help well. I plan to work on this area in the future by not letting people get to me and try to think before I act. This will impact my success in college by being the bigger person in certain situations.

Can it be legalize of the sale of human organs Essay

Can it be legalize of the sale of human organs - Essay Example Thus, it is unnecessary for the sale of human organs to be legalized because it will lead to the loss of many lives. Organ donors, as well as families to the deceased donor, believe that they are obliged to benefit from the organs. However, the governments, brokers as well as hospitals are the ones that benefit from the organ donated by a deceased or a living donor. Thus, legalization of the selling of human organs will only benefit the rich few in the society. Additionally, it is evident that some people are involved in the illegal sale of human organs (This House Would Legalize, 2011). For instance, the Chinese hospitals involve themselves in the sale of the organs of the executed prisoners. From this assertion, it is evident that politics will influence the sale of the organs and, as a result, many people will be convicted and executed in order to meet the demands of the few in the society. Additionally, it is evident that many debtors will be abused by their lenders. It is possib le for the organ lenders to be taking part in the selling of the organs belonging to their debtors in order to quench their demands. Thus, it is crucial to the sale of human organs not to be

FINAL EXAM Essay Example | Topics and Well Written Essays - 750 words

FINAL EXAM - Essay Example This separates personal assets from business assets hence cannot be involved in lawsuits. The other advantage is that cooperate business has a continuity agreement, in that even if one member dies the other shareholders still have it alive. Disadvantages come in when it is required to file many legal documents such as the certificates and articles of incorporation, which may take long and is cumbersome. Another major disadvantage is that cooperate business do get tax deductions when distributing dividends, and this eats up into shareholders earnings. Question 3 "To pierce the corporate veil" refers to the possibility of someone to sue the owners of the corporate business. The corporate shareholders are thus held personally liable for the assets and liabilities of the business. Double taxation happens when the cooperate business is taxed for being a corporation itself and the second time when distributing dividends which are profits paid to shareholders in return of their investments. Question 4 I would prefer to start a partnership business for a small cafe/restraint business, where I would sell beverages and snacks. If managed well, a restaurant business can be very profitable as food is one of the basic needs of a human being implying that customers would always stream into the restaurant provided high quality services are provided. Restaurants do not need a lot of capital and expertise to start, all it needs is a spacious room with furniture, a well stocked kitchen, a couple of employees, cooks and waitresses. I prefer a partnership business with two partners where every partner has equal responsibilities to the business and is involved in the daily operations of the restaurant. Partnerships are relatively easy to start and compared to sole proprietors, the partners can raise a higher capital to start the business. Partners help each other in business decisions for instance interviewing employees or signing in a new contract. In connection to my restraint bu siness, my partner should have a hotel and catering skills to compliment my business skills. With a partnership, it is easier to get credit facilities because they have unlimited liability hence easier to raise sufficient funds to run the restaurant. Lastly, a partnership business is easy to dissolve as there not many legal restrictions. When the partners decide to go separate ways they just need to agree on how to split the assets and benefits after paying all the debts. Question 5 General liability- Here, the court will have to establish who has right to control the work and workers performing the duties. Parties Intentions- The intention of parties is also considered when differentiating an employee and a contractor. The court should check the agreement between the parties. Financial control- In determining a person’s status, financial issues are also important. The court should establish who pays the workers and where they get tools to perform their duties. Tax- If the wo rker is an independent employee, he is supposed to pay taxes from his/her pocket but if the worker is a contractor the hiring parties should pay his taxes. Working time- If the working time is longer than that of a usual contract, then the workers lean more towards the employee side than a contractor. Question 6 In legal terminologies," respondeat superior" means the employer is liable for the mistakes of their employee committed on the scope of work (Marsh &

DINING ROOM MANAGEMENT Assignment Example | Topics and Well Written Essays - 1500 words

DINING ROOM MANAGEMENT - Assignment Example In the preparation of a concept theme of a restaurant involves several considerations (Ignacio 54). This paper will attempt to prepare a concept theme for a restaurant that does not avail quick service to its customers. This restaurant, however, avails all the other types of services. When establishing a restaurant business, it is essential to make a decision regarding the operational strategy. The owner should have a clear idea about the restaurant even before moving forward. The plans for the new restaurant will automatically be composed of the established type of service. The restaurant will possibly be within the fundamental categories of services such as fine dining, full-service restaurants, fat-casual restaurant, and casual restaurant. Unlike other restaurants, this restaurant will not include the quick service option. First, this restaurant will have the characteristics of full-service restaurants. These are the type of restaurants where there is an encapsulation of the idea of moving out to have a meal though that is old-fashioned. These types of restaurants will invite their guests to be seated around the tables while the attendants or servers take the full order of the guests and serve them the foods and the drinks (Huiskamp 489). This restaurant will typically have the establishments of fine dining and partly casual eateries. The employees will include hosts and hostesses, bartenders and servers. It is aimed that the restaurant gains the perceived value with beautiful and unique dà ©cor, special dishes, and renowned chefs. Being a full-service restaurant, it will also encompass casual dining. This will imply that the restaurant will be typically affordable and mostly meant to satisfy the needs of families. It will be offering a full-service table, but the food, service and dà ©cor will be less remarkable than the fine dining

Analysis Of A Linear Accelerator

Analysis Of A Linear Accelerator Nowadays patient with cancer are treated by radiation, surgery, chemotherapy or with a combination of these options. The radiotherapy treatment unit used to deliver radiation to cancerous cells and tissues is the linear accelerator, also known as linac. The linear accelerator has been defined by Khan F. M. (2003) as a device that uses high-frequency electromagnetic waves to accelerate electrons, to high energies through a linear tube. The electron beam itself can be used for treating superficial toumors, or it can strike a target to produce x-rays for treating deep-seated toumors. The energy used for the radiotherapy treatment of deep situated tissues varies from 6-15 MV (photons) and the treatment of superficial toumors (less than 5cm deep) is between 6-20MeV. (Khan, 2003) The purpose of this essay is to describe a linear accelerator, analyse its components in the stand and the gantry of the linac, and explain the principles of operation and then discuss why it is best situated to the task for which it was designed. Some advantages and disadvantages of the linac will also be included in the discussion part of the essay. Main body: Figure 1:http://www.cerebromente.org.br/ As you can see from the schematic picture above, the major components of a linac are: Klystron: source of microwave power Electron gun: source of electrons. Waveguide (feed and accelerating waveguide): microwaves travel through the feed waveguide and then to the accelerating waveguide, where electrons are accelerated from the electron gun. Circulator: a device that prevents microwaves of being reflected back from the accelerator. Cooling water system: cools the components of the linac. Bending magnet: A bending magnet is used to change the direction of the accelerated electron beam from horizontal to vertical. (Hendee et al, 2005) X-ray target: electrons hit the target and produce x-rays. Flattening filter: even out the intensity of the beam. Ionisation chambers: they control the dose leaving the head of the linac. Beam collimation: shape the radiation beam to a certain size Klystron: There are two types of microwave power. The klystron and the magnetron. Magnetrons are used for lower energy linacs. In the high energy linear accelerator klystron is used. All modern linacs have klystrons. Both klystron and magnetron are special types of evacuated tubes that are used to produce microwave power to accelerate electrons. (Karzmark and Morton, 1998). The tube requires a low-power radiofrequency oscillator to supply radiofrequency power to the first cavity called the buncher. (Hendee et al, 2005) In the bunching cavity, electrons produced from the electron gun, are bunched together to regulate their speed. The microwave frequency is thousands times higher than ordinary radio wave frequency. For a linac to work, the microwave frequency needed is 3 billion cycles per second. (3000MHz) (Karzmark and Morton, 1998) Electron gun: The electron gun is part of the klystron. Here, electrons are produced and then accelerated to radiofrequency cavities. The source of electrons is a directly heated filament made from tungsten, which will release electrons by thermionic emission. (Bomford, 2003) Tungsten is used because it is a good thermionic emitter with high atomic number, providing a good source of electrons. Klystrons usually have 3-5 cavities, used to bunch electrons together and increase microwave power amplification. Waveguide: There are two different types of waveguides used in linacs. The first is the feed waveguide and the second is the accelerating waveguide. The first one connects the klystron to the main part of the linac. Sulphur hexafluoride (SF6) is used in the feed waveguide, to stop the arcing of electrons, caused by the microwaves that create strong electric fields. A circulator is placed in the waveguide system, to prevent microwaves being reflected back. Microwaves travel then to the accelerating waveguide. The accelerator guide of a linac requires a high vacuum to prevent power loss and electrical arcing, caused by interactions of electrons with gas molecules.(Cook, 1998)The acceleration of electrons takes place here. The accelerator waveguide bunch and accelerate the electrons with the microwaves. Electrons travel with a high velocity to almost the speed of light. (98% of speed of light) Microwaves travel to the speed of light, so irises are used to slow them down, so that electrons can keep up with the microwaves and be accelerated. There are two types of accelerator waveguide: the travelling and the standing waveguide. The difference between the standing and the travelling wave accelerators is the design of the accelerator waveguide. In the travelling wave accelerator, electrons travel towards the machine and microwaves are absorbed, but in the standing wave accelerator microwaves are reflected back upon themselves. The standing wave accelerator is the main type used in medical linear accelerators. Bending magnet: The electron beam leaving from the accelerator waveguide continues through the bending magnet. This is used to change the direction of the electron beam, to exit through the treatment head. The bending magnet deflects the beam in a loop of 270o, or 90o. The most common degree of bending magnet used in linacs is the 270o achromatic magnet. The important property of this magnet is that the electrons are brought together despite the difference in energies. They are brought back together to the same position, angle, and beam cross section at the target, as they were when they left the accelerator waveguide. X-rays target: The target is made of tungsten because of its high atomic number. When electrons, with their high speed, hit the target, made up from a high atomic number material, they undergo rapid deceleration. This sudden loss of energy results in the formation of x-rays and photons. To maximise the X-ray beam intensity, the transmission target will be thick enough to stop all the electrons bombarding it but thin enough to minimise the self absorption.( Bomford, 2003) In order to switch from photon to electron therapy, the target is removed to allow the electron stream to continue into the head of the machine. Flattening filter: In order to make the beam intensity uniform across the field a flattening filter is used. It is usually made of lead, although tungsten, uranium, steel, aluminium, or a combination has also been used or suggested. The flattening filter absorbs more photons from the centre of the beam and fewer from the periphery of the beam. Ionisation chambers: Ionisation champers measure the amount of radiation leaving the machine, quantified in units Monitor units. Every linac has two ionisation chambers for safety reasons. The ionisation is a round, flat structure, filled with gas, divided into a number of segments, where each segment contains electrodes. When radiation passes through the gas, it is then ionised creating a high charged density that is controlled by the electrodes. The treatment terminates when the readings from the electrodes have reached a pre-set M.U value. Collimation: A primary collimator limits the maximum field size for x-ray therapy (40 x 40cm). It ensures that x-rays leaving the target leave in a forward direction in order to minimise radiation leakage through the head. The treatment field size is defined by the secondary collimator. This collimator reduces the transmission penumbra, since radiation must travel through the entire collimator thickness. It consists of four thick metal blocks, called jaws. There are two pairs of jaws, upper and lower jaws. With the use of asymmetric jaws, by moving each jaw individually, asymmetric field sizes can be produced. Half beam blocking can also be enabling. Different intensity patterns can be produced, from the standard flat beam profile, by moving during treatment. Multi-leaf collimators are finger like projections, 1cm thick. These fingers like projections move independently in order to form the field shape more closely to the shape of the planning target volume. By using MLCs, less radiation is given to normal tissues. Discussion: From the introduction of this essay, the definition of the linac was given. A linac is a high voltage machine, used for the treatment of cancerous cells and tissues. With the structure of a linac this is achieved. By radiating cancerous tissues, with daily radiation treatment, cancerous tissues can be destroyed and then replaced by normal tissues. Every component in the linac is carefully selected for the function for which it is designed. First of all, the klystron is used to produce microwaves, because it is better than a magnetron that is used for lower energy linear accelerators. Because linear accelerators have higher energy beam, klystron are used for production of x-rays. Continuing to the electron gun, tungsten wire or filament is used, because of its high melting point, high atomic number, and it is ductile. With this features tungsten is a good thermionic emitter, is a good source of electrons and can be easily shaped into spiral, in order to create a larger surface area for the electrons to be emitted. In the feed waveguide Sulphur hexafluoride (SF6) is placed with the intention of stopping the arcing of electrons. At the end of the waveguide a circulator is placed so as microwaves cannot be reflected back. As we move on to the accelerating waveguide, and the standing wave accelerator used in linacs, we can see why the standing wave accelerator is used. The backward travelling wave interferes with the forward travelling wave, alternatively constructively and destructively. The resulting standing wave has a magnitude of approximately double that of the travelling wave, and the peak intensity travels along the waveguide at the phase velocity of the travelling wave.(Knapp et al, 1968) Following the waveguide is the bending magnet. Here we have the achromatic magnet where its main task is to change the direction of the electrons, but more important to bring the electrons together despite the difference in energies. A flattening filter is used to make the beam even from the central axis to its peripheral edges, to have homogenous distribution of the dose. Ionisation chambers are essential in a linac. They monitor the dose leaving the treatment head, so that the linear accelerator knows when to end the treatment. Collimation in a linear accelerator is necessary. Without the primary and secondary radiation a linac wouldnt be as suitable for the task for which it was designed. The field size and shape is vital in order to radiate only the cancerous tissues and not normal tissues. Nowadays with the advances of technology and the use not only of MLCs, but also IMRT and IGRT, survival rates of cancer have increased. Last but not least, a linear accelerator can treat a patient with different energy modalities. By removing the target, the electron stream can continue into the head of the machine and then be used for the treatment of superficial toumors. By leaving the target, photons are produced to treat deep-situated toumors. Nowadays most linacs have virtual wedges, compared to some decades ago, where there where only manual wedges. Now radiographers with the use of virtual wedges dont have to concern about manual handling, as they dont have to do anything. I believe that linear accelerators are not perfect. Linacs are extremely expensive to buy, so poor countries dont have the opportunity to treat their patients from cancer. It is hard to keep up with the advances of technology, as everything is very expensive to buy, and only wealthy countries can buy the latest equipment. A disadvantage of switching from photon to electron modalities is that applicators and blocks are used to direct the electrons and shape the beam. Applicators are very heavy. Blocks are made of lead which may cause lead poisoning if they are not handled with care. The only disadvantage with MLCs is that when conforming the beam shape to the PTV, some radiation will be leaking, even when using the tongue and groove effect. Last but not least the linacs to work efficiently they need daily quality assurance tests and maintenance from physicists. Conclusion: Linear accelerator is the main treatment unit used for the treatment of abnormal tissues. With its precise position of the beam, shaped differently for every patient individually, it certainly is the best machine for the treatment of cancer. A linac uses microwaves to accelerate electrons and then hit the target where x-rays are produced. This x-rays are collected and then form the shape of the beam. Nowadays with the rapid advances of technology, linacs in a few years time will be even more efficient than today. Definitely linear accelerators are best suited for the task for which they were designed. All the components of a linear accelerator are carefully selected for its needs. From the smallest to the bigger parts of the linac, are designed for the best outcome. References: BOMFORD, C.K., 2003. Megavoltage beam generators. In: C.K BOMFORD and I.H KUNKLER, ed. Walter and Millers Textbook of Radiotherapy. London: Churchill Livingstone, Pages 162-183. COOK, M., 1998. X-Ray Production. In: A. DUXBURY and P. CHERRY, ed. Practical Radiotherapy Physics and Equipment. London: GMM, Pages 21-26. HENDEE W. R., IBBOTT G. S. and HENDEE E. G., 2005. Radiation Therapy Physics. 3rd ed. Hoboken, New Jersey: Wiley-Liss. KARZMARK, C.J and MORTON, R., 1998. A Primer on Theory and Operation of Linear Accelerators in Radiotherapy. 2nd ed. Madison, Wisconsin: Medical Physics Publishing. KHAN M.F., 2003.The Physics of Radiation Therapy.3rd ed. Philadelphia: Lippincott Williams and Wilkins. KNAPP, E. A., KNAPP, B. C. and POTTER I. M., 1968. Standing Wave High Energy Linear Accelerator Structures. In: HENDEE W. R., IBBOTT G. S. and HENDEE E. G., 2005. Radiation Therapy Physics. 3rd ed. Hoboken, New Jersey: Wiley-Liss.

The Lost Tradition Essay -- Essays Papers

The Lost Tradition Every Sunday was understood to be a family day. No one even thought to make plans with friends or to schedule anything on that day. It was our â€Å"family tradition.† I only wish I appreciated that time with my family more as a child. It always started out the same way. My two brothers and I would awaken to the smell of breakfast, being cooked by my father. We would climb out of bed and wearily make our way to the table. After eating more than we knew we should have, the calm that we once were all in disappeared. The hectic â€Å"getting ready† took over. There was fighting over the bathroom and trying to find lost shoes, even the occasional fist fight between my brothers and me. Although I hated getting ready in such disorganized circumstances, I would love to relive it again. My father rushed the three of us out of the door with barely enough time to make the five minute drive to CCD class. Directly after CCD, we would meet my parents in the church for mass. As much as my brothers and I fought, we knew how to behave in church, and usually the hour passed uneventfully. We got the case of the giggles now and then, but a stern look from my father put that to an end very quickly. The next part of the afternoon was the part I dreaded most. We would all be loaded up into our minivan and taken for long boring drives to the places my parents loved to go. I would have no choice but to stare at the miles of trees and to listen to the local country station for hou...