Physics of Aikido Essay - 2127 Words

Aikido is the martial art that focuses primarily on redirection and control of ones opponent (uke. Pronounced OO-kay). This consists of a set of throws and holds which are intended to subdue and control an uke without permanently harming them. On a spiritual level, Aikido is focused on bringing harmony of the body into harmony of others. Roughly translated Aikido means The Way of Harmony of the Spirit which holds true today, though different schools place different emphasis on the spiritual aspect. Aikido was first created approximatly 80 years ago by Morihei Ueshiba, and took a great many techniques from Jujitsu, Judo and Kenjutsu and modified them. Ueshiba focused on forming a martial art that placed a great emphasis on moral and†¦show more content†¦Highly related to Judo, an art which also seeks to rob an uke of stability, Aikido incorporates many other martial arts as well, all of which contribute to the basic idea of unbalancing your uke by using their own energy against them. Equally important to making an uke unstable is retaining your own stability. A great deal of emphasis is placed upon the ability of an Aikidoist to stay centered. In terms of physics, this is the control over the location of your center of mass. The movement of the center of mass from within ones body to a point where that person is no longer in equilibrium is the reason why people fall down. Well take a closer look at how an Aikidoist manipulates his own center of mass, and the center of m ass of others to perform techniques. Newtons Laws All three of Newtons laws can be applied to Aikido and the techniques therein. Lets take a look at them one at a time. 1) An object in motion tends to remain in motion. An Aikidoist realizes that an object moving in a direction will probably continue in that direction. A giant thug charging at you is not going to be stopped easily, so why bother stopping him? By simply getting out of the way, and avoiding the attack an Aikidoist has already begun a technique. Certain techniques take advantage of the fact that a body in

What Are Mental Prisons Or Unnatural Fears, And The...

83. What Are ‘Mental Prisons’ or Unnatural Fears, and The Process of Liberation? †¢ People of modern age suffer from anxiety disorder the regular emotion of Anxiety which can be described as a subjective unpleasant state of inner turmoil, feeling of dread associated with anticipation of real or imaginative frequently accompanied by nervous demeanor, somatic discomforts, and rumination. Anxiety which is state of uneasiness, worry and over-reactivity with regard to a situation only perceived as menacing, is NOT IDENTICAL with Fear, which is complex relatively proportional and appropriate mobilizing or paralyzing reaction on correctly perceived genuine and immediate threat. Regularly anxious person compulsively focuses on the symptoms of own†¦show more content†¦Animals become proportionally fearful only in genuine life-threatening situations and are instinctively engaged in an attempt to avoid or reduce danger level. If animals cannot avert a danger or prevent attack occurrence, they express audibly a cry of terror, which is kind of automatic prayer t o Providence for assistance, and help is received on the psychic plane. As Martinus pointed out in multitude occasions, the Psychic Help is of tremendous relevance to animals in the specific transition moments and Day-Consciousness transfer into Spiritual World after Physical Death especially in slaughterhouses where horrified animals experience the passion of pathological killers. Incontestable fact is that animals are FREE from FEARS once the real danger is over, and in general terms have a courageous and animated attitude towards Life. †¢ Dissimilarly, Terrestrial Humans lack both the courage to embrace Life and the crucial factor which influences and promotes health happiness – relationship with Godhead. Regretfully, due to the state of massive Cosmic Ignorance a person is not aware of the Existence of PSYCHIC LIFE SAVER, the fact that Human Animals also have ‘Guardian Angels’ – the ‘assigned’ Spiritual Beings always ‘on duty’ to assist when Prayer is sent out. The Irrefutable Cosmic Truth suggests that no a Living Being with the active status of Day Consciousness is without a Spiritual ‘Sentry’

Rhetorical Modes Free Essays

Associate Program Material Appendix C Rhetorical Modes Matrix Rhetorical modes are methods for effectively communicating through language and writing. Complete the following chart to identify the purpose and structure of the various rhetorical modes used in academic writing. Provide at least 2 tips for writing each type of rhetorical device. We will write a custom essay sample on Rhetorical Modes or any similar topic only for you Order Now |Rhetorical Mode |Purpose – Explain when or why |Structure – Explain what organizational |Provide 2 tips for writing in | | |each rhetorical mode is used. method works best with each rhetorical mode. |each rhetorical mode. | |Narration |The purpose of a narration is |Narrations are usually best told in |First ask yourself if you want | | |to tell stories. Narrations can |chronological order. Chronological order is |to write about fiction or | | |be factual or fictional, either |the order in which events are told from |non-fiction. | | |way, they should engage the |beginning to end. Start with a strong | | |readers emotionally. | |introduction to hook your | | | | |readers. | | |An illustration clearly |The structure that works best with an |First decide on an interesting | |Illustration |demonstrates and supports a |illustration is by order of importance. Order|topic. | |point through the use of |of importance is the organizational method |Gather evidence that works in | | |evidence. |that arranges ideas by order of importance. |conjunction with your subject | | | | |and also engages the audience. | | | | | | Description |The purpose of description in |Descriptive essays are best told by spatial |Choose a subject that you wish | | |writing is to make sure the |order. Spatial order is the arrangement of |to describe, such as a person, | | |readers are fully in tune with |ideas based on physical characteristics or |place, or event. | | |the words on the page. appearance. |Fill every part of your essay | | | | |with full vivid sensory | | | | |details, which include alll of | | | | |the five senses. |Classification |The purpose of classification is|Classification essays are organized by its |Choose a topic you know a lot | | |to break down wide ranging |subcategories. It begins with an introduction|about. The more you know about | | |subjects into smaller, more |that introduces the broader topic and then |a topic the easier it will be | | |specific and manageable parts. |the thesis should include how and why the |to break down into groups. | | |topic is divided into subcategories and why. |Make sure you break down each | | | | |topic into three different | | | | |ways, it will help you to think| | | | |more originally . |Process |The purpose of process analysis |A process analysis essay is usually organized|You want to choose a topic that| |analysis |is to explain how something |by chronological order. The steps of the |is interesting, complex, and | | |works and how to do something. |process are told by the order in which they |can be conveyed in a series of | | | |occur. |steps. | | | |Choose a process that you know | | | | |well enough to describe the | | | | |finer details in each step of | | | | |the process. |Definition |The purpose of a definition |A definition essay is organized by opening |Choose a word or phrase complex| | |essay is to define a topic in a |with a general description of the term you |enough to write a bout at length| | |detailed and informative manner. |are defining. Then, you use your definition |or of personal revelance to be | | | |of the term as your thesis. You should also |considered engaging and | | | |use details and examples for the body, and |interesting. | | | |then tie in all the elements of the term and |The context of the term affects| | | |reinforce your thesis to conclude your essay. |the meaning and the definition. | | | | | | | | | | |Compare and |The purpose of a compare and |Compare and contrast essays can be organized |The thesis should clearly | |contrast |contrast essay is to analyze two|by the subjects themselves, first one then |convey why the subjects are | | |subjects that either compares or|the other, or by their individual points, |being compared or contrasted | | |contrasts them or does both. |which discusses each subject in regards to |and what will be learned from | | | |each point. |it. | | | | |Use phrase of comparison or | | | | |contrast to let readers know | | | |how the subjects are being | | | | |analyzed. | |Cause and |Cause and effect essays |There are two key ways that cause and effect |Choose an ev ent that has an | |effect |determine how various events |essays are organized. The first way is by |interesting cause and effect | | |are related. |beginning with the cause and then the effect |relationship, and introduce it | | | |or vice versa, you can begin with the effect |in an engaging way. | | | |and then the cause. Clearly explain and support the| | | | |causes and effects you discuss | | | | |with a wide range of evidence. | |Persuasion |The purpose of persuasion is to |A persuasion essay is made up of five |A thesis that clearly conveys | | |motivate, convince or sway |features. The first feature is the |the opinion of the writer in | | |readers to a certain point of |introduction and thesis. The second feature |clear, consise terms makes for | | |view or opinion. |is opposing and qualifying ideas. a better argument than one that| | | |The third feature is strong evidence in |is vague. | | | |support of the claim. |Be careful of the use of I in | | | |The fourth feature is the style and tone of |your writing, because it can | | | |the language you are using. Lastly, is a |make you seem overly biased and| | | |compelling conclusion. |it takes away from the topic at| | | | |hand. | How to cite Rhetorical Modes, Papers

Sportsmanship free essay sample

One big aspect of sportsmanship, Is that It shows the love that an athlete has for he sport he or she plays. Whether a team wins or loses a game, by simply shaking hands you show good sportsmanship. When the loser tells the winner good game, and congratulates them, not only does this show that this person has been playing this game for a long time, but also that this person has respect for anyone involved in the sport. The same can be said for the winner. If the victor shows respect for the loser, the loser in turn will respect them. No matter how bad a team are beating a team, If a team keeps the score reasonable and keep negative comments about the there team to yourself, you are being a good sport and showing respect to the other team. Believe it or not the other team will notice this, and realize that you respect them, and this will only make them respect you more. We will write a custom essay sample on Sportsmanship or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page Another big controversy in sports is why are players penalized for celebrating, after scoring a goal, making a big shot, or scoring a touchdown? The answer to this question Is not an easy one.When one scores, or make a big play, a player has every right to be happy, and excited, but there Is a point at which the player could cross a nine, and they begin to taunt and disrespect the other team. That is the main reason one gets penalized for excessive celebration, because it is unsportsmanlike to taunt and disrespect your opponent. A player, must learn to be modest, and learn to act like he or she have been there before. One of the biggest words In the definition of sportsmanship Is fair. In every sport, there are players who do not go by the rules and in some way, give themselves a leg up in the competition.A big way athletes do this is by doping, and taking illegal drugs, such as steroids. When players do this, they are cheating. Other players in the league, and on the team have worked hard to get where they are. When players take illegal drugs to give themselves a boost over the competition, it is the biggest sign of disrespect to any sport, or game one plays. This shows that you have become so obsessed with winning, someone will do anything to make sure he or she does not lose. Thats not what sports are about. As children we were taught that soccer,football, baseball, were all games and you want to win, but the most important hinge is that a sport is fun! As you get older things get more competitive and athletes start to lose sight of why they started playing in the first place. To have fun! This is one thing that all athletes need to remember. Sportsmanship is one of the key elements In sports. A team has to be able to win shaking hands. Sportsmanship can be applied anywhere in life not Just in sports. Whether competing for a Job, a promotion, etc. If you are a good sport about it people will have the up most respect for you.

On Globalization and Sovereignty free essay sample

While some people may argue that the rise of modern technology brings about a global market, which subsequently compromises the necessity of sovereign states, this is not the case. Indeed, the perpetual development of superior technology facilitates international trade and communication. However, there is no evidence that the phenomenon called globalization necessarily leads to the dissolution of sovereignty. Globalization may make the state more difficult to manage, but the sovereignty nevertheless still remains. If globalization eradicated state borders, and united the world through its super effective forms of communications and electronic business transactions, then the result would be a singular body of people that has no evident leader to enforce law and order. Therefore, although globalization may create an image of borderless countries, the state still remains to prevent mass chaos and disorder. What is the actual effect of globalization? To say that the rise of technology creates an international trade system would be rather superficial. We will write a custom essay sample on On Globalization and Sovereignty or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page What globalization ultimately inclines towards is a potential market place with common technology, factor endowment, and prices (Adams 167). The result is a levelled playing field across the globe. Competition can start in one place, and have the same potential for success as a business on the other side of the world. The implications of this equilibrium of states, where all states basically provide the same opportunities to its citizens, are multifarious. For example, once the world reaches this equilibrium, do state borders really hold any value? Its as if the world comes together under the umbrella of international economy and trade, becoming a single entity, encompassing all of humanity. However, some countries will not enjoy the full benefits of globalization: the increased reliance on trade, external funds, and DFI [direct foreign investment] may constrain the ability of individual nation-states to pursue social agendas (Hadenius 273). In order to satisfy the global community, individual states face difficulty in dealing with local, national inquiries. Such extremities of international conformities become evident when countries abide to policies that must be made to ensure the stability of the global market. Influential NGOs that have active international agendas (276) will not be so kind as to consider state borders when it comes to fulfilling their goals. While these NGOs, such as the WTO, may have genuinely good intentions in creating a balanced economy and trade, some countries will be negatively affected by such changes. As Hadenius claims, politically weaker nations may find themselves unable to pursue more egalitarian agendas without serious consequences such as outflows of capital (273). When states comply to the demands of the global market, their individual strength weakens, for they must sacrifice sums of money for the sake of supporting globalization and its policies. Subsequently, with less funding to ensure power and authority in their own states, sovereignty is found to be in a dire situation of lack of control. In result, the country is simply a victim of autonomous, structural developments in the world economy (275). What power they had had to be exchanged for the satisfaction of the population, to keep up with the ever-changing trend of the world. Yet globalization does not hold any influence over the borders of a strong nation. Hadeniuss point specifies and focuses more on the weaker, poorer states. He claims so because poorer nations are much more reliant on DFI and external funds, while stronger nations are the ones that provide these funds and dictate the flow of the global market. However, the notion of rich and poor is irrelevant and trivial on the effects of globalization on sovereignty. What remains essential to understand is that in spite of the influences of globalization, states will linger and remain in existence. John Agnew proposes an idea that globalization has merely further complicated an already complex relationship between sovereignty and territory (Agnew 2). Agnews view on globalization is not solely on its economic implications; rather, globalization entails other sophisticated state affairs, such as immigration and national currency (Lentner 136). These complexities of globalization can be extended to Hadeniuss argument; although foreign aid and DFI may be a temporal solution for poorer states, these international interactions weaken states authoritative power and are complexities brought about by the rise of globalization. While complexities may weaken a states ability to govern itself, these exterior influences do not discredit the role of a state. Agnew claims states have never exercised either total political or economic-regulatory monopolies over their territories (Agnew 2). Expanding on his claim, states always have exterior powers that affect decision-making. However, the increase of these exterior influences by globalization does not imply the total loss of control of a state. Other authors, including David Smith, argue the same point: states, especially weaker states, have never been able to guarantee their control over activities within or across their borders (Smith et al. 34). Complexities, complementary with globalization, make state control difficult, but not impossible. Smith also lays out the fundamental types of sovereignty: interdependence, domestic, Westphalian, and international legal sovereignty. He argues that states may enjoy many combinations of these four types of sovereignty. The example he gives is of Taiwan: it may have Westphalian sovereignty (exclusion of external authority in governing), but lack international legal sovereignty (recognition of one state by another) (Smith et al. 35). In any case, globalization may occur, disregarding state borders, but the concept of sovereignty lives on, hardly affected by it. The existence of sovereignty is not eroded by the growth of globalization. However, is sovereignty still necessary? Can the world function solely on the concept of globalization, and without the notion of sovereign states? In addition to Smith stating that sovereignty is not being fundamentally transformed by globalization (34), the notion of sovereignty is absolutely essential in the process of maintaining order throughout the world. When globalization pushes the world into an equilibrium of egalitarian states by producing an equal opportunity for business, there is no authority structure that can definitely choose among competing normative prescriptions (34). NGOs may push states around, influencing decisions here and there, but nevertheless there remains no master organization that holds absolute authority over every state. Therefore, if by globalization a single body of people were to arise, the world would simultaneously plummet into anarchy, causing chaos and disorder ubiquitously. It is for this reason that individual state control is still necessary, even for the sake of globalization itself. Perhaps, one may propose that groups, such as the United Nation, act as a leader for globalization. However, the UN is not a singular entity that is comprised of the population of the world. Rather, the UN contains smaller segments of sovereignty, which subsequently is responsible for a smaller portion of the world population. Unless the world can come as one, under a single ruling group, the concept of sovereignty will stand firm. However, ironically, if the world does unite, and an authoritative figure holds power over the population, then globalization effectively becomes a state-instituted phenomenon. This contradiction hints at the necessity of sovereignty in order for globalization to occur. Globalization is without doubt a compelling phenomenon that allows interaction between peoples across the entire planet. Yet, it would be rash and illogical to assume that such heightened global communication and trade infers the dissolution of sovereignty. Globalization can create more complexities to state affairs and make border control more difficult, but the sovereign state nevertheless remains to maintain order. Anarchy would arise if globalization were to rise without sovereignty. However, the individual is free to utilize globalization to their own benefit. As Hadenius artistically says, Modern technology was supposed to make Big Brother omnipotent, watching you into submission; instead, it enabled us to watch Big Brother into impotence (Hadenius 263-4), we ought to manipulate the implications of globalization to better our corrupt political system. With mass communication and media, we have the option to be aware of political issues throughout the globe, and more importantly, to correct critical issues in society. It is within the individuals volition to make use of globalization as an opportunity to better their own lives, but also the lives of others throughout the world as well.

Sickle Cell Anemia Essays - RTT, Hematopathology, Hemoglobins

Sickle Cell Anemia Essays - RTT, Hematopathology, Hemoglobins Sickle Cell Anemia The problem is that sickle cell anemia affects about 72,000 Americans in the United States. Sickle cell anemia is an inherited disease in which the body is unable to produce normal hemoglobin, an iron-containing protein. Abnormal hemoglobin can morph cells that can become lodged in narrow blood vessels, blocking oxygen from reaching organs and tissues. The effects of sickle cell anemia are bouts of extreme pain, infectious, fever, jaundice, stroke, slow growth, organ, and failure. Sickle cell anemia hurts many people today in fact it hurts about 72,000 Americans. But some doctors are finding cures for this inherited disease. This disease causes mainly strokes and fever. With this disease a stroke is not predictable, a stroke can happen as early as a one month old as a baby. It can hurt a person really bad because it causes them to not be able to do many things like can't play sports, and things that gets your heart pumping because if the red blood cells gets clogged up it can causes a stroke because oxygen can't flow. Most Americans who have sickle cell anemia are of African descent. The disease also affects Americans from the Caribbean, Central America, and parts of South America, Turkey, Greece, Italy, the Middle East and East India. Since sickle cell anemia is an inherited disease if both parents have the trait for sickle cell, their baby's chances of having sickle cell disease is one in four. Many doctors are trying to find cures for this disease by trying the solution on patients. Doctors at Emory University and University of Mississippi Medical Center in Jackson, Chicago. Doctors in Emory University in Atlanta credited an experimental stem cell transplant that for the first time is not from a related donor. This transplant cured the inherited disease from Keone Penn who is 13 years old from Georgia. He suffered a stroke at 5 years old and had a fever of 106 degrees, I almost died (Ferraro, Newspaper Article) What the doctors did was replaced the boy's bone marrow with stem cells taken from the umbilical cord blood of an infant not related to him. Dr. Ruby Bellevue of New York Methodist Hospital in Brooklyn has patient that he wants to do the transplant procedure on, but he is waiting for more studies to come out to see what the long-term effects are. Some effects could be rejection, complications, and/or death. For many years, doctors could only treat the sickle cell di sease with blood transfusions and antibiotics. But until now, the only hope for a cure has been through bone marrow transplants, dangerous and rarely performed because they require a match between donor and the person receiving it. The good thing about stem cell transplants is does not require as precise a match. For Keone the 13 years old kid was worth it. I am happy. This has been my wish my whole life, to not have sickle cell. (Ferraro, Newspaper Article) The doctors of University of Mississippi Medical Center use Doppler ultrasound to examine head and neck blood flow. The ultrasound measures the speed of the blood in the vessels. Early detection can help and decrease the risk of stroke. The program involved in this problem is the National Institutes of Health declared September as Sickle Cell Awareness Month. The educational and research organization have promoted awareness of sickle cell disease, a group of inherited disorders characterized by anemia which means a reduced number of red blood cell and the production of sickle hemoglobin is a molecule found in red blood cells that carries oxygen from the lungs to other parts of the body. My suggestion for dealing with this problem is to go to the doctor to get an examination if you play any sports or go for a jog or run and experiment any difficulty breathing. If you don't have trouble breathing, maybe if you feel dizzy or feel like you about to blackout when you do something I recommend going to the doctors for an examination. It is better to find out the problem first before you will experiment a stroke a high fever that can cause a death. I think early detection help a lot and could

POLicy ANALYSIS Essay Example | Topics and Well Written Essays - 500 words

POLicy ANALYSIS - Essay Example The policy makers therefore adopt different strategies for addressing the concerns of nurses as these approaches can be more beneficial and less costly for the nurses as well as the patients. The nurse workforce in a particular hospital is based on licensed practical nurses, registered nurses and licensed nurses and then there are nurses’ aides. Both the LPNs and RNs are licensed by the same State in which they reside and practice. It is the responsibility of the RNs to access the needs of the patients, administration treatments and medications and develop patient plans. The maintenance of the minimum nurse to patient ratio will be beneficial for the patients as well as the nurses. There is a need for the policymakers to realize not only the potential benefits associated with the ratio but also potential expenses associated with these benefits. Minimum nurse staffing ratio helps the hospital to improve as well as increase the quality of its operations. The patients are more satisfied by the working of the staff and there are enough nurses present in the hospital to deal with emergency cases which results in low mortality rates. Acquiring minimum nurse staffing ratio also allows the hospital to give their full attention to each and every patient and not neglect the needs of any of them. On the other hand not having adequate number of nurses will misbalance the effective working of the hospital and the lives of many patients will be at stake. Aiken, Clarke, Sloane, Sochalski, & Silber in their article empahsize upon the importance of staffing ratio on the health of patients. There is no doubt about the fact that the staffing ratios help to alleviate the shortage of nurses. It discusses the fact that the working conditions of the hospitals may affect the number nurses willing to work within an hospital. Therefore staffing ratios help in improving the quality of hospitals which affect the patients’ mortality rate and

Dinler v. City of New York, 607 F.3d. 923 (2d. Cir. 2010) Case Study

Dinler v. City of New York, 607 F.3d. 923 (2d. Cir. 2010) - Case Study Example Thus, it was ordered that reports by covert operatives are of confidential nature and, therefore, cannot be revealed to the defendants on the grounds of safeguarding public interest. The court further added that the plaintiffs did not have sufficient reasons to warrant the production of the police reports, which are confidential in nature. Thus, the writ was granted and the orders of the lower court were vacated. The case was previously heard by the court for the Southern District of New York where the plaintiffs had petitioned and during the trials they requested for the production of undercover police reports. The court directed the city to produce the documents for verification by plaintiffs during the trial. The plaintiffs alleged that the mass arrest of the demonstrators constituted the violation of their â€Å"state and federal constitutional rights† (United States District Court Southern District of New York, 2012, p.1). During the trial, they requested the production of police reports by covert operatives and the city filed writ for mandamus on the grounds that such documents cannot be divulged before the public. However, the district court ordered that the documents be produced and as an alternative suggested that it be done â€Å"attorney’s eyes only basis† (Adams, n.d., p.1). In this scenario, the city had to resort to seeking a writ for mandamus as producing the documents for the scrutiny of the attorney would also have compromised the confidentiality of the reports. The Court of Appeal granted the writ on the grounds that the petition of the city qualifies for a mandamus as it raised â€Å"novel and significant† questions of law (p.1). The court also agreed to the fact that police reports are entitled for â€Å"law enforcement privilege† and thus the these are not to be divulged to either the plaintiff or their attorneys (p.1). The main

Tax inversions, benefits and pitfalls Term Paper

Tax inversions, benefits and pitfalls - Term Paper Example This issue was put to great publicity in April 2014 and came together with the proposed merger between two companies, AstraZeneca and Pfizer. Even though multinational public corporations have recently received more press coverage on tax inversions, middle-market and private corporations can invert and realize same tax benefits. A change of the legal location of the company from the United States to another nation allows the company to benefit from certain laws in that nation. Typical benefits that make corporations in the U.S to re-incorporate in other countries include banking laws that are more flexible. In addition, they also benefit by getting friendly corporate governance rules and lower tax rates. Bermuda is one of the most common destinations for tax inversions due to several reasons. The principal driver is because Bermuda does not tax capital gains. Also, it does not have any corporate income, dividend tax or profit. Typically, shareholders of such corporations need to pay taxes from the profits realized after inversion. Worse enough, the tax inversion transaction is mostly a stock transaction where the shareholders get no money to pay taxes on their profits in the stock. In that case, inversions are a long term play for shareholders of corporations which can bear the short term tax bite. Tax inversion also leads to unemployment in the country of origin of such corporations. The tax inversions do not typically alter the structure of operation for the company. Mostly, it means adding a smaller office in the new foreign location of the company. Therefore, even though on rare occasions, tax inversions lead to unemployment. The Bush administration passed a legislation that required corporations to continue paying taxes under current rules. Under this Act, the corporate minimum tax rules would still apply. Current rules where corporations control

Interlayer Effect: Si-based Double Junction Tandem Solar

Interlayer Effect: Si-based Double Junction Tandem Solar Investigation of Interlayer Effect on Si-based Double Junction Tandem Solar Cell Abstract: Silicon-based double junction tandem solar cell was fabricated and simulated using wxAMPS software. Nano structure of SiO2/ Si3N4 interlayer was inserted between the silicon and InGaN junction to investigate the effect on the quantum efficiency of the Si-based solar cell. The quantum efficiency characterizations were studied under AM1.5 solar spectrum at 300o K. SiO2 was found to be an excellent interlayer for Si-based double junction tandem solar cell compared to Si3N4 and exhibit better quantum efficiency. The addition of SiO2 and Si3N4 nano structure interlayer between the Si and InGaN improved the Jsc by 5.79% and 2.21% respectively compared to the absence of interlayer. Key-Words: Silicon solar cell, interlayer, silicon dioxide, silicon nitride, quantum efficiency, wxAMPS 1  Introduction Due to its low material cost and ease of manufacturing, silicon-based solar cells are preferred for energy conversion. Advances in the technology have significantly improved the overall performance of silicon solar cells. Besides, Si has better cooling capability compared to sapphire [1]. Si has larger thermal conductivity which promises much faster thermal dissipation [2]. Since solar cells operate under high temperature, this characteristic is strongly desired. Indium gallium nitride (InGaN) is one of the best semiconductor materials for optoelectronics which can operate in high-temperature. In addition, InGaN is a widely used for multi-junction tandem solar cells with high conversion efficiency and shown a better resistance to radiation damage compared to other materials. It provides variety of band gap energies as the band gap changes with the In-Ga ratio. Due to its potential in cost reduction and faster thermal dissipation, researchers are committed to study InGaN-on-Si technol ogies. As Si and InGaN is having large relative lattice mismatch, the conversion efficiency of the device is limited. This issue leads to phase separations. Because of that, suitable interlayer or absorber layer is desired to ensure each layer to match. Thermal lattice mismatch was reported by Krost et. al in 2002 stating that cracking of GaN on Si usually occurs due to the large thermal mismatch of GaN. The thermal stress can be reduced significantly by insertion of low-temperature AlN interlayers, introducing multiple AlGaN/GaN interlayers, and growing on prepatterned substrates [3]. The interface traps at the nitride/Si interface exhibit dissimilar properties from those at the SiO2/Si interface in some aspects. Thermally grown SiO2, the currently established gate dielectric for Si-based MOS devices, possesses remarkable electronic properties that are unmatched by other materials. Both SiO2 and Si3N4 are equally transparent even for high energy edge UV band of solar spectrum. SiO2 is highly technically established materials as a passivation layer for Si based MOS technology and it may also be used for integration of PD technology [4]. Si3N4 is also potential coating materials against degradation of detecting device even in high radiation environment and temperature [5]. Implementation of double junction solar cell is one of the alternatives in enhancing the output characteristic of solar cell [6]. Users demand a better efficiency and higher output current of solar cell. Thus, we investigated the structure of InGaN-on-Si solar cell with the presence of different interlayer (SiO2 and Si3N4) which was inserted between Si and InGaN layer to intensify the light conversion in the cell. This structure enables the increase of current of both top and bottom cell by reducing the recombination effects [7]. In this paper, we focused on the quantum efficiency which is one of the criteria that must be considered as we can evaluate the amount of current that the cell will produce when exposed to sunlight. 2  Experimental Procedure The structure as shown in the Fig. 1 was fabricated using wxAMPS software which was developed by Prof. Rockett and Dr. Yiming Liu of UIUC and Prof. Fonash of PSU. The solar cells were grown on a n-type silicon substrate. Three different experiments have been conducted; without interlayer, with SiO2 interlayer and with Si3N4 interlayer. Fig. 1- Structure of the solar cell Composition of In0.4Ga0.6N with Eg=1.99 eVwas used in all three experiments. The output characteristics were studied under AM1.5 solar spectrum at 300oK. InGaN is chemically a n-type semiconductor because of the presence of nitrogen in the composition. Mg is used to dope the InGaN in order to make it p-type [8]. 3  Result and Discussion Fig. 1 presents the internal quantum efficiency of the three conducted experiments. Fig. 2- Internal Quantum Efficiency From Fig. 2, insertion of SiO2interlayer shows better IQE compared to Si3N4 and without interlayer. The difference in the IQE can be seen at high energy spectrum. The difference is due to the recombination at the surface of the cells. When carriers are generated near the surface, and since blue light for example is absorbed very close to the surface, quantum efficiency at high energy edge which absorbed very close to the surface will be affected by the front surface recombination. Presence of interlayer leads to a higher generation rate and it is more significant at the wavelength ÃŽ »2/ Si3N4is introduced between the Si and InGaN layer, the absorption is further improved and enhances the diffusion length. The highest quantum efficiency is recorded at the wavelength of 650-700 nm. The surface recombination and diffusion length in the bottom cell tends to shift the peak to lower energy edge. The properties of SiO2 and Si3N4 itself differs from each other. SiO2 has a refractive index o f 1.57 while Si3N4 with refractive index of 2.05. SiO2 permits selective diffusions into silicon wafer. Fig. 3- Current density without interlayer Since the solar cells are made up of p-type and n-type semiconductors, electrons from the n-region near the p–n junctionlikely to diffuse into the p region. As these electrons diffuse, positively charged ions (donors) are left in the n-region. On the other hand, holes from the p-type region near the p–n junction start to diffuse into the n- region. As we analyze the current density behavior based on the structure in Fig. 1, the bottom cell (Si) which is stacked with InGaN layer determines the current density with the presence/absence of interlayer. It can be seen that recombination that occur in the bottom cell affected its total performance. Besides, the in-plane lattice mismatch between Si and InGaN was reported by Henini in his book. Direct growth of InGaN layer on Si (without buffer or interlayer) gives in-plane mismatch from -7.81% to -17%; depending on the content of Indium and Gallium [9]. Direct growth of InGaN on Si makes some part of the InGaN diffused into th e Si. Carrier recombinations at localized states arise due to this lattice mismatch which leads to lower Jsc. Besides, cracking of GaN on Si usually occurs due to the large thermal mismatch of GaN. This lattice mismatch effect can be reduced by inserting interlayer which can reduce the thermal stress between the junction of InGaN and Si. GaN-based semiconductor is not well suited for direct growth on Si. Fig. 4- Current density for Si3N4 interlayer From Fig. 4, the behavior of the current density with Si3N4 interlayer is almost the same with no interlayer but it gives lower recombination rate hence produces greater current-density compared to the one in Fig. 3. At 0.08  µm-0.1  µm, it can be observed that Jn and Jp stay constant at a deeper position from the bottom cell. The final alignment and function of InGaN cell is strongly dependent on the starting substrate type, orientation, substrate pre-treatment, type of buffer or inter layer and growth conditions. High recombination rate as shown in Fig.3 and Fig. 4 is not desired. Thus, Si3N4 is not so suitable to be used as an interlayer between Si and InGaN. Fig. 5- Current density SiO2 for interlayer Fig. 5 shows the current density at the bottom cell when SiO2 is used as interlayer. Unlike Si3N4, cells with SiO2 as its interlayer give less recombination rate. The type and magnitude of recombination processes in the cell greatly affected the minority carrier lifetime and the diffusion length. The recombination rate will depend on the number of defects present in the material. Defects here may refer to the doping concentration, dopants or the properties of the material itself. Less interface defects are shown by SiO2 and this is proven by nowadays Si fabrication technology which uses SiO2 as gate interface. Even though both SiO2 and Si3N4 are equally transparent for high energy edge of solar spectrum, but the interface traps at the nitride/Si interface exhibit contradictory properties from those at the SiO2/Si interface in some aspects. No interlayer SiO2 interlayer Si3N4 interlayer Voc (V) 1.5886 1.6371 1.5912 Jsc (mA/cm2) 6.4706 6.8454 6.6136 FF (%) 48.439 52.2130 48.8326 Efficiency (%) 4.9791 5.8513 5.1390 Table 1- Output characteristics of the solar cell based on different interlayer The output characteristics as shown in Table 1 are relatively important in determining the performance of solar cells based on different interlayer. It can be seen that SiO2gives a higher Voc, Jsc, fill factor and efficiency compared to Si3N4. The addition of SiO2/Si3N4 nano structure interlayer between the Si and InGaN improves the Jsc by 5.79% and 2.21% respectively compared to the absence of interlayer. 4  Conclusion The effect of different interlayer on Si-based solar cell is studied. InGaN is not well suited fordirectgrowthonsiliconsubstrate. SiO2 has shown to be an excellent interlayer between Si and InGaN cell. It appears that suitable choice of interlayer is important to match the top cell and the bottom cell. The interlayer also will give a significant effect on its quantum efficiency and total current density. 5 Acknowledgement I would like to thank Pusat Penyelidikan dan Inovasi UMS and Kerajaan Malaysia for the funding of this project (Project code: FRG0307-TK-1/2012). References: C.Y.Liuet al.,Nitride-based concentrator solar cells grown on Si substrates, Solar Energy Materials Solar Cells117(2013)54–58 Miro Zeman Janez Krc. Electrical and Optical Modelling of Thin-Film Silicon Solar Cells.MRS Proceedings. Vol. 989. No. 1. Cambridge University Press, 2007. Krost, Alois, and Armin Dadgar. GaN-based optoelectronics on silicon substrates.Materials Science and Engineering: B93.1 (2002): 77-84. Eujune Lee et, al., IEEE Electron Device Letters, Vol. 30, No. 5, May 2009 Sinje K-C et. al., 26th EU PVSEC European Photovoltaic Solar Energy Conference Exhibition, 05-09 Sept., 2011 L. A. Vilbois et al., Simulation of a Solar Cell Based on InGaN, Energy Procedia 18 ( 2012 ) 795 – 806 El Gmili, Y., et al. Multilayered InGaN/GaN structure vs. single InGaN layer for solar cell applications: A comparative study.ActaMaterialia61.17 (2013): 6587-6596. Islam, Rafiqul, et al. MOVPE Growth of InxGa1-xN(x~0.4) and Fabrication of Homo-junction Solar Cells.Journal of Materials Science Technology(2012). Henini, Mohamed. Molecular beam epitaxy from research to mass-production, Newnes (1996): 33-36. Chang, J-Y., et al. Numerical Investigation of High-Efficiency InGaN-Based Multijunction Solar Cell. (2013): 1-1. Despeisse, M., et al. Resistive interlayer for improved performance of thin film silicon solar cells on highly textured substrate.Applied Physics Letters96.7 (2010): 073507-073507. Araà ºjo, Andreia, et al. Role of a disperse carbon interlayer on the performances of tandem a-Si solar cells.Science and Technology of Advanced Materials14.4 (2013): 045009. Liu, Yiming, Yun Sun, and Angus Rockett. A new simulation software of solar cells—wxAMPS.Solar Energy Materials and Solar Cells98 (2012): 124-128. Liu, Yiming, Yun Sun, and Angus Rockett. Batch simulation of solar cells by using Matlab and wxAMPS. InPhotovoltaic Specialists Conference (PVSC), 2012 38th IEEE, pp. 000902-000905. IEEE, 2012.

Freedom of Press or Danger to Troops? Essay examples -- essays researc

Freedom of Press or Danger to Troops? The news has been an important source of information for as long as it has been around. News during a time of war is sometimes the only way a family member, friend, or general public have any idea what the soldiers are going through. Having this source of information can help rally support for our troops when they need all the support they can get. As reporters are granted more access to military operations the information they are provided, and have to report on, become a great responsibility and they should make sure to only make public what should be made public. Information is increasingly becoming the most important weapon in any militaries arsenal, so we should be more careful as to how that information is obtained and dispersed. With respect to the war in Iraq and other military operations abroad I don’t feel the press should be required to be given as much information or granted as much battlefield access as they have been. I am all for the freedom of the press and being informed as to what is happening to our troops, but to many times has information been distributed that could have had a negative impact on the outcome of an operation. One example is when Geraldo Rivera basically drew out in the sand on live television the position of the troops he was tagging along with. â€Å"Geraldo Rivera, reporting from Iraq for Fox News last week, drew a map in the sand, on camera, that gave away his unit's location† (Poniewozik 1). As he should...