Monday, January 20, 2020
Graduation Speech: Building County High School :: Graduation Speech, Commencement Address
When I first began school in this district at County Junior High in seventh grade, I had no idea that I, along with my classmates, would have the privilege of building the New High School. Of course I don't mean the physical, brick-by-brick building; I mean the building of High School's spirit, the tradition of pride and achievement that permeates every brick, every part of our school. I had no idea what impact we would have in both the academic and athletic realms. Our group activities have fought for and won honors that can be envied by every other school. Whose football team broke another school's six year winning streak? Whose debate team is now known nationally as one of the best affiliate teams in the country? Whose band marched for President Clinton's inauguration? Yes, it was County High School's teams that accomplished these and other noteworthy feats. But I believe it was we, the first class to spend four years at County, who played a large part in these accomplishments. We came here as eager freshmen, bringing our energy and ideas to this school. I remember all the - glitches and gremlins that plagued us, how History class was as hot as Death Valley and English class colder than Siberia. But we survived. Sophomore year saw the graduation of County High School's first class. And last year, we said goodbye to the class of '11. Many of us had role models amongst them, yet more of us had friends. But as last year drew to a close, we realized that this year would be our year. It was our turn to lead Neda, it was our turn to shine. And shine we did, with a brilliance enriched by our four years of experience in this school. I cannot attempt to list the awards and honors earned by our class, but I can try to express the immense pride I feel when I realize that I belong to County High's class of 2012.
Sunday, January 12, 2020
Cumberland Metal Industries
In January of 1980, Cumberland Metal Industries (CMI) had developed a new product for the pile driving industry. Its new pad, made of tightly curled metal, had the potential to break into an industry where little or no innovation was taking place. The CMI product testing showed great efficiency gains over the current standard asbestos product. The existing competition consisted of small firms, few of which had the knowledge or resources to design and develop new products. CMI seemed on the verge of breaking into a new market, where its product would be the technological front-runner. It now needed to show its customers the value its product would provide, and price its new product accordingly. Without any consideration to potential savings realized in the price of the product, the CMI pad provides additional value to the customer in two ways, time and safety. Using asbestos pads, a pile driver was able to drive approximately 150-160 feet per hour. Using the CMI pads, the same pile driver was able to drive 200 feet per hour. Additionally, the CMI pads never went above a temperature of 250oF, which allowed them to be handled almost immediately. This increase in speed and resiliency accounted for a productivity increase of 33% faster driving time. With regards to safety, the CMI pad alleviates any health hazard concerns, which many workers were starting to feel towards the asbestos pads. This in the long run could save the customer significant money in healthcare costs and legal fees, should asbestos be proven to cause health concerns. The primary target market for the CMI pad would be the Engineering/Construction contractors and Independent pile-driving contractors. These two categories would benefit the most from a lower cost alternative to asbestos, as well as from the time and safety efficiencies. The secondary target market would be the Pile Hammer Distributors and Renting companies. This category may be less welcoming to the CMI pads, as the efficiencies realized by the contractors could translate into lost revenues due to fewer pads being needed and equipment being returned early. Part of the promotional aspect of this product launch should focus on the industry subject matter experts, the Pile Hammer Manufacturers, and the Architectural/Consulting Engineers. While these groups would not directly purchase this product, their opinions and specifications would be influential to the target markets. CMI had already submitted its pad for testing to Professor R. Stephen McCormack of Pennsylvania A&M University, who is well respected in the pile-driving field. While his results are not available, early indications are that his findings will be favorable. Should that be the case, CMI should promote these findings to the manufacturers and engineers, and work with them to have the CMI pads legitimized as a viable option within the industry. In deciding where to set the price on the new pads, CMI must first review its manufacturing costs, as well as determine the value its product would bring to its clients. The projected manufacturing costs are outlined in Table 1, with one option showing the costs using existing equipment, and the other showing the costs with a $50,000 investment in new permanent tooling equipment. Table 1 [pic] As is shown in Table 1, the permanent tooling reduces manufacturing costs by 53%. CMI would have to sell 633 units to break even on the initial $50,000 investment, however in my opinion I believe this is well worth it. By lowering its manufacturing costs, CMI can increase its margins, as well as increase its maneuverability with the product price. I will therefore base my pricing decision on the assumption that CMI invested in the permanent tooling equipment. CMI senior management has indicated that they are looking to receive a 50% margin on this product. Therefore, the minimum price option to be considered is $138. 36 per pad. Part of CMIââ¬â¢s product testing included providing the pads to two responsible contractors, Colerick Foundation Company and Fazio Construction, for them to test against the asbestos pads in working conditions. From the Colerick test, we learned that the contractor would have needed 480 asbestos pads, at a total cost of $1,000, to complete the job. In comparison, only 6 CMI pads would have been required. Therefore, in this situation, the exact comparable price per the job costs for a CMI pad to an asbestos pad would be ($1,000/6) $166. 66 per pad. The total number of feet for the job was 15,000, and from the test results we learned that the asbestos pads lasted for 31. 25 feet of pile driving, while the CMI pads lasted for 2,500. This translates into 80 asbestos pads needed for everyone one CMI pad. The average price of an asbestos pad is $3. 00; therefore the value to the contractor of a CMI pad would be (80 x $3) $240. In the Fazio test, the contractor would have used 600 asbestos pads, at a total job cost of $2,000. Again, in comparison, only 5 CMI pads would have been needed. In this instance, the comparable price of a CMI pad would be ($2,000/5) $400 per pad. The total number of feet for this job was 12,000, and from these test results we learned that the asbestos pads lasted for 20 feet of pile driving, while the CMI pads lasted for 2,400. In this example, 120 asbestos pads would be needed for every one CMI pad. The value of a CMI pad to this contractor would be (120 x $3) $360. While these results vary somewhat, they clearly show that the CMI pads last significantly longer than the current asbestos pads. For the purpose of determining price, I will extrapolate from the findings that a CMI pad lasts for 2,500 feet of pile driving, while an asbestos pad last for 25 feet of pile driving. Therefore, the value of one CMI pad to a contractor is comparable to 100 asbestos pads. Given the asbestos price of $3. 00 per pad, the dollar value of a CMI pad to a contractor is $300 per pad. Because CMI is the first to enter the market, with relatively weak competition, and protection from a patent, I recommend a skimming pricing strategy, with a focus on customer value. As a result, I would price the CMI pad at $162 per pad to our distributors, with an MSRP of $270. This would allow the distributors to market the product at a 10% price discount over asbestos, as well as the 33% increase in time productivity, and achieve a 40% margin. Due to the limited initial manufacturing volume of 250 pads per month, I believe the best course of action is to maximize possible revenue on each pad, rather than try for market penetration. The price of $162 would provide CMI a margin of 57. 5%, which exceeds the requirement of senior management, and would allow the company to invest in future research and development, or perhaps an advertising program should it wish to increase market share in the future.
Saturday, January 4, 2020
New York City Essay - 1741 Words
New York City Every time I hear this song it makes me long to leave all of my responsibilities and head off to the city of dreams. A trip to New York has been a dream of mine since I was a little girl. I have always wanted to visit the place of tall buildings, history, and where culture is intertwined with its people. I have wanted to live the fast pace life of a New Yorker, where I could stand outside and see, smell, and taste all of the experiences that this city has to offer. I have been building and building this ideal image in my mind for so long. If I ever get to New York, will I be disappointed by the city that never sleeps? The city that is a part of almost every movie I watch. Can New York live up to the expectations I haveâ⬠¦show more contentâ⬠¦My husband thought this to be a bit corny, but not me. How exciting it was to hail my first ever cab to the city. The taxi ride itself was long, but I was to busy to care, because I was taking in all of the sites like a vacuum. The true mo ment of the taxi ride came to be once we entered the city of Manhattan. The taxi driver was true to form by honking, speeding when allowed, and not caring if we cut off anyone during our drive. The traffic from the airport to the city was a big jumbled mess. I have never experienced traffic this bad before. I was so excited once our taxi man paid the toll to get into Manhattan. Paying that toll was like gaining access to a secret society. The city, it people and the buildings welcomed us with open arms. The sounds of the city penetrated the walls of the cab as we drove through the streets of Manhattan. I could hardly wait to partake in the action that was happening outside. The buildings themselves were an amazing site to behold. The buildings took on personalities of their own. Each building was bigger and more graceful than the next. When lights were added to the mix it was a dazzling combination. The city itself felt like a great big hug, and I felt overwhelmed by its power. The city allowed me to become part of it just like many others many years ago who immigrated to this awesome city. As I was looking out of the cab I finally got to see in person the sight of all sights; Times Square. The main juncture ofShow MoreRelatedNew York And York City864 Words à |à 4 PagesNew York, New York. With the exception of Ted Cruz, everyone loves New York. Among its wonders, New York state contains New York City, the most populous city in the U.S. New York is also known for its beautiful la kes and mountains, a great wine growing region, and lots of farms. New York City has the largest concentration of billionaires anywhere on the globe, the financial heart of the world known as Wall Street, and is the ultimate destination for every wannabe taxi cab driver in the world. NewRead MoreThe City Of New York City748 Words à |à 3 Pagesperson as they walk the streets of New York City. The rush of a city can often be overwhelming. Even though that may be true, 80.7 percent of the U.S. population lived in urban areas as of the 2010 Census. Living in New York City is better than living in a Haysi. Living in a city offers many more conveniences, opportunities, and more diversity. Living in a city offers many amenities and service that might very well not be available in a rural area. New York City for example, has terrible trafficRead MoreNew York : The City Essay1283 Words à |à 6 PagesNew York: the city that never sleeps, the Big Apple, the most lively city in America. It is home of the greatest pizza (right behind Italy) and the greatest bagels. It is home to the some of the greatest food in the world, as you canââ¬â¢t walk a hundred feet without seeing a different restaurant. It is home to nearly eight and a half million people, many of them world renowned names like Jay-Z, Robert De Niro, and Adam Sandler. I must admit, though, I am a little biased. This is because I come to UMassRead MoreThe New City Of New York1299 Words à |à 6 PagesIt was not easy for Johnny to move into a new city. It was very problematic for him to move into a new city because he knew no one, and he had no friends. The new city that Johnny moved into was New York. It is also known as The Big Apple. That city has a population of 8.6 million people. New York has many attractions. Examples of them are: Empire State Building, Statue Of Liberty and Time Square. Johnny always had a dream to go to New York and see these attractions, but he did not picture it likeRead MoreNew York City1607 Words à |à 7 PagesNew York City is always bustling, after all, it is known as the city that never sleeps. There are only a few places that offers an escape. Ever since Governors Island have opened its doors for visitors, it has been the escape. However, the Island needs to go through some changes to be a perfect recreational area worthy for the people of New York. History To understand the Governors Island and fix its problems, we need to look at the history. It was originally owned by the Lenape tribe and used asRead MoreNew York City : The City Of The World914 Words à |à 4 Pages the city that never sleeps and the place that I call home -- New York City. Although there are many other cities across the United States, New York City has a certain je ne sais quoi about it, that makes it seem better than the rest. Home to the Statue of Liberty, Times Square, Central Park, the Empire State Building, and many other landmarks and attractions, New York City is a touristââ¬â¢s dream come true. Unfortunately, people like me, who have lived and grown up here, tend to find the city and itsRead MoreThe New York City Council1154 Words à |à 5 Pagesbrought to a legislative body. In the case of the New York City Council, the bill is introduced into the Council at a Stated Meeting and becomes a law after an intricate voting or vetoing process with the Counci l and the Mayor of New York City (ââ¬Å"Legislative Processâ⬠). In the last year, many bills were passed by the New York City Council. While browsing through the list of bills passed in the last year, a bill in particular stood out to me ââ¬â ââ¬Å"Reducing city government emission of greenhouse gases by 40Read MoreMiami And New York City947 Words à |à 4 PagesMiami and New York City are cities located at complete opposite sides of the United States. Miami, the city where sunshine, palm trees, and beautiful beaches are the norm, is located in the southern part of Florida. Meanwhile, New York City, famously referred to as the city that never sleeps, is located right in the heart of New York. Both, have numerous compelling similarities, as well as many distinguished differences that give each their own distinct identity. Whether itââ¬â¢s their weather, culturalRead MoreNew York is the City of Dreams662 Words à |à 3 Pages New York is the city of opportunity, it has been a home for many who have immigrated through the famous Elis Island in hopes of creating a better life and living an american dream, for others it is an inspiration and a place to chase their dreams. The city that never sleeps is a place where millions of people daily are all trying to accomplish something. The song ââ¬Å"Empire State of Mindâ⬠by rapper Jay Z and Alicia Keys released in October of 2009, reminds us just what New York represents. Both artistsRead MoreHunger Of New York City1374 Words à |à 6 Pages Hunger in New York City Since the recession started in 2007, the national statistics of unemployment, low-income households, and hunger have increased yearly. Even after the recession had ended in 2009 the economic issues are still very prominent. Everything economically related to the health and welfare of the vast majority of our American citizens, has sky rocketed in a very negative way. Students, parents, children and families alike have, and continue to struggle with hunger on a day to
Friday, December 27, 2019
A Classic Filled With Energy And Controversy - 2290 Words
A Classic Filled with Energy and Controversy ââ¬Å"Vision is the art of seeing what is impossible to othersâ⬠(Swift). This quote by author and satirist Jonathan Swift explains that a person can see beyond something that others donââ¬â¢t see if you put your mind to it. Jonathan Swift did exactly that when creating his famous novel, Gulliverââ¬â¢s Travels. Swift made this novel because he loved writing satire as well as making fun of politicians. In the eighteenth century, he was an Irish clergyman who opposed the British Parliamentââ¬â¢s ideas and despised their increasing power over the common people. The idea of Gulliverââ¬â¢s Travels came about and Swift wanted to show the English people that their government was becoming overpowering and corrupt. Gulliverââ¬â¢s Travels is an adventurous story of a man named Lemuel Gulliver and how he sails from England on crazy journeys, encountering various people from Lilliputians to Yahoos. Throughout his novel, Swift created a puzzle for his readers to put t ogether. As Gulliver meets all of these characters and describes what he finds, the reader identifies that Swift has a unique outlook on humans in his society. In Gulliverââ¬â¢s Travels, Swift uses three elements including satire, utopian or dystopian societies, and irony and immortality to portray the different types of humans. Jonathan Swift was one of the best satirist of his time and his book had an astounding effect on English literature. He tried getting his point across by using sarcasm,Show MoreRelatedEssay about The Women of For Colored Girls1189 Words à |à 5 Pagescreating an emotional response within the audience (Nathan, 2001).â⬠The decision to bring this play to film caused much controversy because of the difference between film and stage acting. Although many would agree that Perryââ¬â¢s movie adaptation captured the essence and purpose of the play with its drama, mystery, humor, tragedy and compassion, many still preferred the energy of the stage play. ââ¬Å"Translating Shanges work to the screen, Perry, whose films nearly all began as plays, is tone-deaf toRead MoreIndustrialization of Hemp: An Alternative Resource 535 Words à |à 2 Pagesresource has never been so high, something has to be done. The use of industrial hemp is a viable alternative resource too many depleting assets plastic kills! Many people know, but plastic also kills many endangered desert animals. Classic is filled with harmful chemicals one of these chemicals is Bisphenol A(BPA).BPA has been known to leave too many serious diseases and health issues. One another downfall of plastic is it takes longer to decompose. What makes him a better alternative isRead MoreThe leadership and environment impact of BP international2274 Words à |à 10 PagesHistory and Current Information In 1908 Anglo-Persian Oil Company, the predecessor of British Petroleum (BP), made the first oil discovery in the Middle East. Ever since, BP has been a leading player in the global energy market. The London-based multinational is the world s third-largest energy company, behind Exxon Mobil and Royal Dutch Shell. Officially incorporated in 1909 as the Anglo-Persian Oil Company, BP turned 100 years old in 2009 (Hall, 2010). Their story began in 1901 when Australian-BritishRead MoreEssay about Mannerism in Florence and Rome2819 Words à |à 12 Pagespaintings, very lively and ornate Christ in the House of Levi - avoids all reference of supernatural - symmetrical mood brings us back to Raphael and da Vinci - paints this as almost a banquet - devoid of mans soul or Intention of mans soul - filled Chrst side with bafoons, drunkards, etc. and not with the twelve apostles - thinks that this is showing the Last Supper but never said because then he would get in trouble - the figures in the piece are not symmetrical Sculpture Mannerism, FirstRead MorePepsico Case8696 Words à |à 35 Pagesalso offered its first compostable bags. The outer layer of 10.5 ounce SunChip bags are now biodegradable, as they are composed of a type of acid found in plants. 5 As with all big companies, of course, Frito-Lay has experienced its share of controversies in its history. In 1967, Frito-Lay introduced a cartoon character named Frito Bandito, a Mexican bandit with a sombrero who stole other peopleââ¬â¢s corn chips by gunpoint. The Mexican American population launched a series of protests. They felt thatRead More The Role of Washington County, Ohio in the Success of the Underground Railroad3729 Words à |à 15 Pageswill then give background information on four stations in the Underground Railroad in Washington County. This section will also tell about the conductors of these stations. Brief History of the Underground Railroad Slavery caused extreme controversy within the United States and eventually led to a Civil War. There were many peaceful efforts to stop slavery, but when these were unsuccessful some people decided to fight slavery other ways. One tactic that was discovered was indirectly hittingRead MoreEssay on Silent Spring - Rachel Carson30092 Words à |à 121 Pagesmake her one of the most important women of the twentieth century. Carson was recruited to help a friend from Duxbury, Massachusetts, challenge a state mosquito control program that seemedto be wiping out birds. This and another widely publicized controversy over a similar development in the Southeast led Carson to write on the mounting scientific evidence about the risks of pesticides. Doubting that she could find a magazine that would publish an article on so gloomy a topic, Carson produced an entireRead MoreIndian Beverage Industry Report15071 Words à |à 61 Pagesprepared for human consumption. Beverages almost always largely c onsist of water. Drinks often consumed include: Water (both flat or carbonated),Juice based drinks, Soft drinks, Sports and Energy drinks,Alcoholic beverages like beer or spirits ,Coffee, tea ,Dairy products like milk. Commonly, drinks are filled into containers, like glass or plastic bottles, steel or aluminum cans as well as cardboard supported packages, like the TetraPak or others. Filling of beverages can be done cold, hot, ambientRead More John Coltrane Essay5593 Words à |à 23 Pagesof 1957, after a year and a half with the quintet, Coltrane left or was dropped (the truth remains unclear), the reason seems to have been indulgence not in stylistic extremism but in heroin and alcohol, problems he conquered that same year. The controversy had to do not only with his harmonic experimentation, on which Dexter Gordon was initially the chief influence, but with the speed (to some, purely chaotic) of his playing and the jaggedness (to some, unmusical) of his phrasing. All three ch aracteristicsRead MoreMovie Marketing6914 Words à |à 28 Pagesbeen timed to protect the theatrical revenue model. But with piracy at record levels globally, a variety of pricing -- and timing -- strategies are being tested, like pricing the DVDs very cheaply. 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Thursday, December 19, 2019
Analysis Of The Poem Hulga s Spiritual Blindness
Thesis: Hulgaââ¬â¢s spiritual blindness is also the ending of this story. Hulga concerns herself with what is which relates the her disdainful rejection of the spiritual, so Hulga takes from the passage exactly what Heidegger is arguing against. (Hubbord, p53) Hulga is ethically problematic but nonetheless useful in Oââ¬â¢ Connorââ¬â¢s vision of the damning and damned, universe.â⬠She is disabled and physically carries the stigma of abnormality, metaphorically emboding the ââ¬Å"sinsâ⬠of the world with her.â⬠(Behling p.88) ââ¬Å"Hulga is a 32 year-old with a Ph.D. in philosophy and an artificial leg. Because of her weak heart, she lives at home with her mother, if not for her condition, Hulga ââ¬Å"would be for from these red hills and good country people. She would be in a university lecturing to people who knew what she was talking aboutâ⬠. (Behling p.88) Hulgaââ¬â¢s commitment to nihilism is not so absolute as to give pointer such and unqualified claim, though as the story demonstrates, she has flirted with a force she does not understand and which is competent to violate her soul in a most obscene manner, thus exposing its emptiness.(Edmondson III, p.158) The remainder of the story is a study in manipulation, seduction and subjugation with Pointer as the teacher. Hulga becomes vulnerable because, of her empty wounded state of psyche. ââ¬Å"Spiritually and physically crippledâ⬠ââ¬Å"a wooden part of her soul that correspondes to her wooden leg.â⬠(Behling p.158) Hulgaââ¬â¢s physical afflictions her heart condition,
Tuesday, December 10, 2019
Schindlers List Summary Example For Students
Schindlers List Summary Schindlerââ¬â¢s List retells the heroic actions of Oskar Schindler. Once a poor Czechoslovakian businessman, Oskar Schindler sees the oncoming world war as a chance to reinvigorate his life by taking advantage of the Nazi regimeââ¬â¢s hatred towards Jews. Oskar would find great success in his munitions factory by through securing large deals from Nazi officers, due to his close connections, and his use of cheap Jewish labor. However, as Oskar beared witness to more and more heinous crimes committed against the Jews, Oskar could no longer stand by while thousands of innocent Jews were slaughtered at the hand of Nazis. This would change Oskarââ¬â¢s goal from trying to make a fortune by taking advantage of the Jews to attempting to save as many Jews as possible. From this it is evident that Oskar Schindler is the hero from Schindlerââ¬â¢s List as he single handedly saved thousands of lives. Truly one of the greatest heroes to come out of the Holocaust, Oskar Schindler risked everything to save all the Jews he could. Initially indifferent about the poor treatment of the Jews, Schindler would change his ways and work to save the Jews, only adding to his greatness displaying his change of heart to do what is just even when it is against his well-being. Schindlerââ¬â¢s disregard for the life of the Jews in at the beginning of the film can be seen during his meeting with the old man with one arm who wanted the thank him. Rather than being receptive to the praise he received, Schindler was angered by this man as he was a liability to the profits he was so keen on making. However after seeing the cruel clearance of the Jewish ghettos, specifically the little girl in the red dress, Schindler sees just how disgusting and inhumane the Naziââ¬â¢s truly are and is determined to make a difference. After several lucrative contracts with the Naziââ¬â¢s Schindler had amasses a massive fortune, one large enough to buy the lives of over a thousand Jews. Not only this, but after saving their lives by giving them use in the ammunition factory, Schindler would go about and offset many of the machines to make his bullets and guns ineffective in combat, helping the Allied war effort. This scheme despite being ingenious was tremendously costly and while Schindler had a rather impressive fortune, he ran broke by the end of the war. This only shows his hero like characteristics even more though, as he sacrificed everything he has owned simply to save the lives of people he knew nothing about, thus truly making Schindler the hero of Schindlerââ¬â¢s List. In summation, the hero of Steven Spielbergââ¬â¢s, Schindlerââ¬â¢s List, is non other than Oskar Schindler. His actions during the Holocaust is nothing short of a real-life Superman, as he sacrificed everything, both his money and lifestyle, to save the lives of Jews. Had it not been for Schindlerââ¬â¢s strong mental fortitude and ability to place people above himself, many of the Jews seen in the film, including Itzhak Stern would have been killed in the many mass murderers that took place. While others may argue that Schindler was not a true hero as his just intention did not come about until after his viewing of the Nazi crimes, to many others this only proves that Schindler is the hero as it takes twice the courage for an ordinary man to go above and beyond to reinforce the law than a law enforcing office who had trained their whole lives to protect and preserve the sanctity of not only laws but human rights.
Tuesday, December 3, 2019
Solar Cells Today Are Mostly Made Of Silicon, One Of The Most Common E
Solar cells today are mostly made of silicon, one of the most common elements on Earth. The crystalline silicon solar cell was one of the first types to be developed and it is still the most common type in use today. They do not pollute the atmosphere and they leave behind no harmful waste products. Photovoltaic cells work effectively even in cloudy weather and unlike solar heaters, are more efficient at low temperatures. They do their job silently and there are no moving parts to wear out. It is no wonder that one marvels on how such a device would function. To understand how a solar cell works, it is necessary to go back to some basic atomic concepts. In the simplest model of the atom, electrons orbit a central nucleus, composed of protons and neutrons. each electron carries one negative charge and each proton one positive charge. Neutrons carry no charge. Every atom has the same number of electrons as there are protons, so, on the whole, it is electrically neutral. The electrons have discrete kinetic energy levels, which increase with the orbital radius. When atoms bond together to form a solid, the electron energy levels merge into bands. In electrical conductors, these bands are continuous but in insulators and semiconductors there is an "energy gap", in which no electron orbits can exist, between the inner valence band and outer conduction band [Book 1]. Valence electrons help to bind together the atoms in a solid by orbiting 2 adjacent nucleii, while conduction electrons, being less closely bound to the nucleii, are free to move in response to an applied voltage or electric field. The fewer conduction electrons there are, the higher the electrical resistivity of the material. In semiconductors, the materials from which solar sells are made, the energy gap Eg is fairly small. Because of this, electrons in the valence band can easily be made to jump to the conduction band by the injection of energy, either in the form of heat or light [Book 4]. This ex plains why the high resistivity of semiconductors decreases as the temperature is raised or the material illuminated. The excitation of valence electrons to the conduction band is best accomplished when the semiconductor is in the crystalline state, i.e. when the atoms are arranged in a precise geometrical formation or "lattice". At room temperature and low illumination, pure or so-called "intrinsic" semiconductors have a high resistivity. But the resistivity can be greatly reduced by "doping", i.e. introducing a very small amount of impurity, of the order of one in a million atoms. There are 2 kinds of dopant. Those which have more valence electrons that the semiconductor itself are called "donors" and those which have fewer are termed "acceptors" [Book 2]. In a silicon crystal, each atom has 4 valence electrons, which are shared with a neighbouring atom to form a stable tetrahedral structure. Phosphorus, which has 5 valence electrons, is a donor and causes extra electrons to a ppear in the conduction band. Silicon so doped is called "n-type" [Book 5]. On the other hand, boron, with a valence of 3, is an acceptor, leaving so-called "holes" in the lattice, which act like positive charges and render the silicon "p-type"[Book 5]. The drawings in Figure 1.2 are 2-dimensional representations of n- and p-type silicon crystals, in which the atomic nucleii in the lattice are indicated by circles and the bonding valence electrons are shown as lines between the atoms. Holes, like electrons, will remove under the influence of an applied voltage but, as the mechanism of their movement is valence electron substitution from atom to atom, they are less mobile than the free conduction electrons [Book 2]. In a n-on-p crystalline silicon solar cell, a shadow junction is formed by diffusing phosphorus into a boron-based base. At the junction, conduction electrons from donor atoms in the n-region diffuse into the p-region and combine with holes in acceptor atoms, producing a layer of negatively-charged impurity atoms. The opposite action also takes place, holes from acceptor atoms in the p-region crossing into the n-region, combining with electrons and producing positively-charged impurity atoms [Book 4]. The net result of these movements is the disappearance of conduction
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