Literary Traits in Araby and AP Essay Example

Literary Traits in Araby and AP Essay Example Literary Traits in Araby and AP Essay Literary Traits in Araby and AP Essay The stories of â€Å"Araby† and â€Å"AP† share the same literary traits from each character which is the protagonist. The main point of the two is that they focus on a young male who is pressured by his conscience to untangle the difference between life’s reality and the fantasies that play in his head. The young man does indeed recognize the difference is what turns him in the direction of an emotional catastrophe. It was obvious that the two young males were rookies in the matter of romance. They did not have the will and strength to share their feelings and emotions with the ladies they were attracted to, but they did evolve from an innocent young male to a level of maturity. One comparison between the stories is the truth that the main character, has made incredible efforts in trying to gain the love and the expectations of their love lady, and mainly focused upon especially toward which he gives all his attention and emotions to. The young men come, â€Å"face to face with the damages of the objection† (Wells, 1993). The rejection that they get in return is too big for them to endure. Updike is well-known for taking works from author’s and shifting them so they replicate a greater modern taste. As the story stays the same, the weather is rare to Updike. The reason why there are similarities, in addition, to change from Joyce’s piece. The three of the most featured views of the two stories over literary component were details, plot, and theme; such as the characteristics of the authors’ works, each of their work provides its own viewpoint upon the young man’s obsession. The descriptive terms are shared by both stories, however, there is a resemblance that occurs with the ending, as well (Doloff 114). The theme of â€Å"Araby† and â€Å"A P† are very similar to one another that the differences are somewhat insignificant to the eye. Both stories start off with a young man who is dealing with one of the toughest life lesso

Definition of Diffusion in Chemistry

Definition of Diffusion in Chemistry Diffusion is the movement of a fluid from an area of higher concentration to an area of lower concentration. Diffusion is a result of the kinetic properties of particles of matter. The particles will mix until they are evenly distributed. Diffusion may also be thought of as the movement of particles down a concentration gradient. The term diffusion comes from the Latin word diffundere, which means to spread out. Examples of Diffusion H2S(g) in a test tube will slowly diffuse into the air of a lab until equilibrium is reached.Food coloring in water diffuses until its evenly distributed throughout the liquid.Perfume diffuses throughout an entire room.Adding a dot of dye to gelatin is a good example. The color will slowly diffuse throughout the gel. Note, however, most of the common examples of diffusion also illustrate other mass transport processes. For example, when perfume is smelled across a room, air currents or convection are more of a factor than diffusion. Convection also plays a large role in the dispersion of food coloring in water. How Diffusion Works In diffusion, particles move down a concentration gradient. Diffusion is different from other transport processes in that it results in mixing without bulk matter flow. How it works is that molecules in motion from thermal energy randomly move about. Over time, this random walk leads to uniform distribution of different particles. In reality, atoms and molecules only appear to move randomly. Most of their motion results from collisions with other particles. Increasing temperature or pressure increases the rate of diffusion.

Physics and Art Essay Example | Topics and Well Written Essays - 1000 words

Physics and Art - Essay Example It originated in Abbey Church of St. Denis in Paris as a vision of Abbot Suger. He wanted to create a physical representation of Heavenly Jerusalem. It is characterized by gothic arches, ribbed vaults, clustered columns, and flying buttresses. This style is usually associated with cathedrals and churches. The gothic arch, characterized by a tendency to form a point at its apex and typically even jointed, symbolizes an admiration to heaven, and it channels the weight onto the bearing piers or columns at a steep angle, thus making the structure stronger. Examples of this can be found in the central large window of the following image as well as in the two smaller windows high up on on the towers. The ribbed vaults are used to roof irregular shapes. These are usually seen in areas spanning windows of many structures but were also used to support heavy roofing material in larger sized rooms without the need for as many interior columns. These styles were adopted by different countries like Portugal, France, Spain, & England. Big Ben is one of London’s famous structures. At night, the clock face of the tower is illuminated, creating an amazing view to everybody looking at it. As the following image shows, the clock faces are designed based on the Arts and Crafts movement with its emphasis on the stained glass construction. This design also enables some of the face pieces to be removed for the inspection of the hands.The faces are set in iron framework with the surround of the dials and the inner face heavily gilded. They are approximately 21 feet in diameter. Big Ben does not refer to the clock itself, but to a bell hung within that clock. It has a 9-0" diameter, is 7-6" high, and weighs 13 tons 10 cwts 3 qtrs 15lbs (13,760 Kg). It is the most famous bell ever cast at the Whitechapel Bell Foundry only a few miles away from Westminster Tower. Look to the photo to the right for a concept of the scale of the great

Qualitative analysis using the transcript provided Essay - 1

Qualitative analysis using the transcript provided - Essay Example I am like a pig stuck in the middle of everything. I want to do my job well. I want to help the people in the community but I have to also listen to the people in charge of me because they are my bosses. They say one thing, the people out there, they want something else. What can I do? Sometimes my hands are tied up. But I do try to do things to make a difference to the people out there – those ones in the rural communities in the district. There are many things which they are facing which can affect their health these days. Maybe I can help them to sort some of this out by working with them. P. Yes. It’s me. There’s nobody else. I deliver training on health issues such as hygiene. I try to help people to understand how they need to wash their hands before they prepare food or something like that...the children, they can get so sick with running stomachs which is bad. Or sometimes, if there is an outbreak, then I will do something different, something about what the trouble is. If there is cholera it is not about prevention it is about action and it needs to be quick and co-ordinated. But it is difficult for some people when they do not have soap or when they have to fetch water from some other place or people are sick and cannot work in the fields. Umm, but really it’s not for me to tell people what to do. I am not their mother or their father but I can try to help them to understand how they can help themselves. Sometimes they listen and sometimes they don’t. The old ones sometimes say ‘who is this young thing who is coming to tell us what it do when we have lived all this time?’ Hopefully you are just putting things into people’s heads and, you know, making them think that next time they will do something. Maybe if they are worried and they can speak to you if you are friendly. So yeah, it is only me that does†¦it can be a struggle†¦(fades off). P. Me, I am the one who does

Introduction to Prokaryotes Essay Example for Free

Introduction to Prokaryotes Essay Prokaryotes are single-celled organisms that can survive in extreme environments. Bacteria is the more numerous type of prokaryotes. The group hypothesizes that the samples taken from different environments will all cultivate diverse morphology in fast growing rates in each environment. The aseptic technique was used to cultivate bacteria from different environments. The diversity of morphology and the growing rate of the bacteria was different in each environment. Introduction Prokaryotes are the oldest known life-forms, having existed for the last 3. 5 billion years. Microscopic in size, they are single-celled organisms. Prokaryotic species can survive in extreme habitats that the other life-forms are not capable of inhabiting. Prokaryotes have different shapes, the three most common shapes are spherical (cocci), rod shaped (bacilli), and spiral (spirilla). The prokaryotic cellular structures are unique to their classification. Prokaryotes have an external cell wall and a plasma membrane. The cell wall keeps the shape of the cell, protects the cell, and averts the cells from bursting in a hyposmotic environment. Prokaryotic cells contain a unique material called peptidoglycan (Sadava et al. , 2011). See more: how to write an introduction Also metabolic diversity is among the criteria used in classifying prokaryotes. The term nutrition refers to the means an organism uses to obtain two energy sources: energy and a carbon source. Carbon sources may be either organic, meaning from a living organism, or inorganic, such as carbon dioxide. Prokaryotes split into two lineages known as Archae and Bacteria. The Bacteria are more numerous than the Archae. Bacteria can be endospore-forming bacteria. Bacteria that form endospores are able to survive harsh and severe conditions. Bacteria can also be Enteric Bacteria, they inhabit the intestinal tracts of animals. One species is Escheria coli. Wild-type Escheria strains are able to grow on a variety of carbon and energy sources, such as sugars and amino acids. Some strains of Escheria are pathogenic. The detection of Escheria coli in water is a sign of contamination. Another group of pathogenic enteric bacteria are members of the genus Salmonella. These members are responsible for food poisoning and typhoid. Prokaryotes play very important roles in our environment. They are involved in the cycling of nutrients and elements in a variety of ways. Many prokaryotes are decomposers that metabolize organic compounds in dead organisms. These decompositions processes result in the return of vast quantities of carbon dioxide, inorganic nitrogen, and sulfur to our ecosystems. Other species are important as symbiotic partners with other organisms (Walsh et. al. , 2010). The diversity of the prokaryotic world is huge, and to have a better sense of knowledge of bacteria diversity in different environments an experiment to observe bacteria growth diversity in colder temperature is conducted. The group hypothesizes that the samples taken from different environments will all cultivate diverse morphology in fast growing rates in each environment. The independent variable in the experiment is the temperature control and the dependent variable is the number of colonies. Materials and Methods Seven different environments were chosen to create bacteria from and cultivated on a nutrient-rich media in eight Petri dishes. The bacteria are cultivated on TSA medium, an all-purpose medium used for cultivating all types of bacteria. Sterile water and sterile swabs are used to sample the bacteria from the environment. To make sure that the bacteria was loosened from the environment and stuck on to the swab, the swab was dipped in the sterile water immediately before taking the sample. Carefully opened the Petri dish and swiped the swab across the plate in a â€Å"Z† pattern. Closed the Petri dish and marked it with its corresponding environment. This was repeated seven times each with a different environment. The first environment was the frame of the classroom chalkboard. The second environment was the chair seat of the classroom. The third environment was the bottom of the shoe of one of our group members. The fourth environment was the floor mat inside the doorway of the Biology building. The fifth nvironment was the stair railing handle from the stairwell of the Biology building. The sixth environment was the spacebar on the keyboard of the laboratory computer. The seventh environment was the mouthpiece of the water fountain in the Biology building. To enable us to check whether or not our aseptic technique was effective the eight Petri dish was our control plate that was struck with the sterile water only. These streaks with sterile water represent control treatments. The bacteria was incubated at 37 °C for 2-3 days and then put into the refrigerator for storage. Results Two of the Petri dishes had small bacteria diversity and also a slow growth rate- the chair seat of laboratory environment sample and the water fountain mouthpiece sample (Table 1). Three of the Petri dishes had medium bacteria diversity and regular growth- the frame of the chalkboard, the stair railing handle from the stairwell, and the spacebar of the keyboard (Table 1). The other two Petri dishes had medium bacteria diversity and fast growth rate- the bottom of the shoe and the floor mat inside the doorway of the Biology building (Table 1). The Petri dish with the sterile water streaks had no bacteria growth or diversity indicating our aseptic technique was effective. Discussion The results that were obtained in the experiment did not support the hypothesis that there would be large diversity and fast growing rates in each environment. Every environment sample had its own growth rate and bacteria diversity. The primary reason may be that conditions are rarely optimum. Scientists who study bacteria try to create the optimum environment in the lab: culture medium with the necessary energy source, nutrients, pH, and temperature, in which bacteria grow predictably. Most of the strains used in the classroom either require oxygen for growth or grow better with oxygen. These bacteria will grow better on agar plates, where air readily diffuses into the bacterial colony, or in liquid cultures that are shaken. Since diffusion of oxygen into liquid depends on the surface area, it is important to have a large surface; volume ratio. This means that cultures will grow best in flasks in which the volume of liquid is small relative to the size of the vessel. Also another factor that affects growth is the nutritional medium. Bacteria grow best when optimal amounts of nutrients are provided.

War and Peace Essay: The Importance of Sonya -- War Peace

The Importance of Sonya in War and Peace Leo Tolstoy's War and Peace speculates deeply about history, religious life and human brotherhood. Most readers focus on the characters of Natasha, Prince Andrew, and Pierre. Another character named Sonya, who is an orphaned cousin, is staying with the Rostov family. Sonya is overshadowed by the other characters, however, she is vital to the rounding out of the other characters in the novel. The people she loves most take her life of commitment and sacrifice for granted. The reader is thus also inclined to give little emphasis to her role in their lives and in the novel as a whole. As someone who has essentially nothing, Sonya is willing to give everything she has to those she loves. She gives of herself willingly and thanklessly. This life of sacrifice truly embodies Sonya's generous character. This genuine nature of her character allows her to reveal so much about those with whom she interacts throughout the novel. With Sonya's seeming "simplicity" in the background, Tolstoy fully develops the characters of Natasha and Nicholas. He uses Sonya as a contrast for his heroine, Natasha, and also as a chart of growth for Natasha's brother, Nicholas. Tolstoy even uses Sonya as a contrast to Princess Mary. Here, if one looks deeper, one will find that there is very little contrast at all between the two women. Most importantly, Sonya is an illustration of society's effects on a poor selfless young girl who puts her needs below those of all others. Tolstoy employs Sonya's character in a variety of situations. Without Sonya, a great deal of his novel's depth and richness would be lost. Sonya is first introduced as Count Rostov's fifteen-year-old niece who ... ... all. Just as the characters in the novel never really appreciate all that Sonya does for them, the reader puts very little emphasis on all that Sonya does to enhance the entire novel. Sonya serves as a truly reflective mirror to Natasha who "never needed to sacrifice herself, but made others sacrifice themselves for her and yet was beloved by everybody"(903). Sonya's presence also helps the growth of Nicholas and reveals a great deal about the society in which she lives. The importance of Sonya's character to War and Peace is immense, yet overshadowed by characters deemed more "important" than she. Sonya tends to be put in the background of this novel as she is put in the background of the lives of those whom she loves. Without her Leo Tolstoy's novel would greatly diminished. Leo Tolstoy, War and Peace, Book of the Month Club, Inc., New York.

Going It Alone Essay

There are three main aspects of the theme ‘Going it Alone and these are Circumstance, Process and Consequences. â€Å"The Black Balloon† represents each of these three aspects through the characters within the film and these are enhanced by the techniques used by the director Ellisa Downs. Circumstance is all about why you are going it alone. It can be a choice to reject the conformist attitudes and values of society or it can be something that has been forced upon you. Within the first scene of ‘The Black Balloon’ Elissa Downs uses the symbolism of the neighbours watching from behind windows and across the street. This symbolism creates empathy for the protagonist. This shows that Thomas and his family are and have been judged by the modern society due to their difference. The young kids insults within the first scene are an example of colloquial or vernacular language, this accurately reflects the crude nature of some kids today. This shows us that prejudice can be a main cause of being forced to ‘Go it Alone’. Within the second scene of the film ‘Thomas’ First day of School’ Thomas is wearing boardies contrasted against the other boys who are wearing speedos. It is a metaphor for the already forged division between Thomas and the other boys in his class and acknowledges that he is an outsider. All of these techniques show us that ‘Going it Alone’ is something that can be forced upon us and is not always chosen. * Going it Alone can definitely be detrimental to individuals emotional wellbeing. The experience of going it alone can impact on the values, beliefs and character of an individual. It may also involve the compromise of values or the loss of significant relationship. * Within the scene ‘By The River’ Downs uses the symbolism of Thomas’ relationship with Jacquie, it is almost like she is a bridge to the outside world and a way to escape his family. Another technique within this scene is the montage of shots within the army base, this shows the growth of understanding Jacquie undergoes and how their relationship grows. ‘Going it Alone has provided a chance for positive personal growth for both Thomas and Jacquie. These techniques show us that ‘Going it Alone’ can provide us with very positive things like stronger relationships and opportunity for personal growth. Going it Alone can provide physical and emotional distance in order to bring about new understandings, knowledge and skills. These are very positive consequences of ‘Going it Alone’, but there are also very negative consequences. Within the scene of ‘By the River’ Thomas and Jacquie lying on the ground. The framing is symmetrical and emphasizes proximity and intimacy. This demonstrate the benefits and mutuality of going it alone. Both have gone alone (from family and circumstance) but have gained a positive bond in the process. The rain serves as an additional motif of cleansing to reflect the power of their relationship to help provide a new perspective on the difficulties they have had â€Å"going it alone†. These three aspects combine to show the concept of ‘Going it Alone’ in the film the Black Balloon. Ellissa Downs uses common techniques such as camera angles, framing and montage to shape the meaning of the concept of ‘Going it Alone’.

Clinical Reflection Essay

The first three weeks in my clinical placement at Facility, I have already gained a lot of practical experience that is different from what I am familiar with. During our orientation at the facility, we met the nurse manager of the third floor who is courteous enough to share a little bit of information about working in the facility and how the system works in the long- term care facility. The nurse manager even told us, that she is also an international educated nurse. Knowing this has inspired me to become successful in my chosen career. After the orientation, our group was divided into two and we were given directions on which wing we will be assigned. There were three of us in my group, and each one of us was assigned to a resident attendant. We were given instructions to just shadow and observe on how things are being done during the first three hours of the resident attendant’s shift. Since I had the experience in a long-term care facility, I am familiar with some of the procedures and routines that are being done by the Personal Support Worker (PSW). That being said, I could say that I was comfortable in assisting the resident attendant/ PSW in providing nursing care to the clients. Although I was familiar and comfortable with the setting of a long-term care facility, I still felt anxious on how I can provide the best care possible for the residents. In this clinical placement, I have learned that being too comfortable and excited is not always a good thing especially for a student. Because of my eagerness to learn new things, I was not able to pay attention on the sign that was posted in a clients’ room. The client was in isolation for contact precaution. The incident happened while I was walking at the hallway and the client called my attention by waving her hand. It made me think that she needed help and I immediately came to her aid without even looking at the sign. The PSW saw me going out from the clients’ room and told me right away that I should not be in the clients’ room without any personal protection equipment (PPE). I suddenly realized that I broke a policy that is highly implemented in every healthcare facility, and that is the â€Å"Infection Control†. My teacher saw what happened and reminded me about the rules in the facility. I apologized and owned up to my mistake. I was embarrassed of what I have done, but also I have learned something that I will never forget. I have learned to be more aware and attentive of my surroundings. As a nurse, I should be one-step ahead, especially when it comes to clients’ safety. I almost put the client at risk by not following the directives on the precaution signs posted on the door of the resident. It may be the risk that I don’t know that I could actually cause greater harm, for this reason I need to be more vigilant and use practice routines in all patient care activities.

Biography of Srinivasa Ramanujan, Mathematical Genius

Biography of Srinivasa Ramanujan, Mathematical Genius Srinivasa Ramanujan (born December 22, 1887 in Erode, India) was an Indian mathematician who made substantial contributions to mathematics- including results in number theory, analysis, and infinite series- despite having little formal training in math. Fast Facts: Srinivasa Ramanujan Full Name: Srinivasa Aiyangar RamanujanKnown For: Prolific mathematicianParents’ Names: K. Srinivasa Aiyangar, KomalatammalBorn: December 22, 1887 in Erode, IndiaDied: April 26, 1920 at age 32 in Kumbakonam, IndiaSpouse: JanakiammalInteresting Fact: Ramanujans life is depicted in a book published in 1991 and a 2015 biographical film, both titled The Man Who Knew Infinity. Early Life and Education Ramanujan was born on December 22, 1887, in Erode, a city in southern India. His father, K. Srinivasa Aiyangar, was an accountant, and his mother Komalatammal was the daughter of a city official. Though Ramanujan’s family was of the Brahmin caste, the highest social class in India, they lived in poverty. Ramanujan began attending school at the age of 5. In 1898, he transferred to Town High School in Kumbakonam. Even at a young age, Ramanujan demonstrated extraordinary proficiency in math, impressing his teachers and upperclassmen. However, it was G.S. Carr’s book, A Synopsis of Elementary Results in Pure Mathematics, which reportedly spurred Ramanujan to become obsessed with the subject. Having no access to other books, Ramanujan taught himself mathematics using Carr’s book, whose topics included integral calculus and power series calculations. This concise book would have an unfortunate impact on the way Ramanujan wrote down his mathematical results later, as his writings included too few details for many people to understand how he arrived at his results. Ramanujan was so interested in studying mathematics that his formal education effectively came to a standstill. At the age of 16, Ramanujan matriculated at the Government College in Kumbakonam on a scholarship, but lost his scholarship the next year because he had neglected his other studies. He then failed the First Arts examination in 1906, which would have allowed him to matriculate at the University of Madras, passing math but failing his other subjects. Career For the next few years, Ramanujan worked independently on mathematics, writing down results in two notebooks. In 1909, he began publishing work in the Journal of the Indian Mathematical Society, which gained him recognition for his work despite lacking a university education. Needing employment, Ramanujan became a clerk in 1912 but continued his mathematics research and gained even more recognition. Receiving encouragement from a number of people, including the mathematician Seshu Iyer, Ramanujan sent over a letter along with about 120 mathematical theorems to G. H. Hardy, a lecturer in mathematics at Cambridge University in England. Hardy, thinking that the writer could either be a mathematician who was playing a prank or a previously undiscovered genius, asked another mathematician J.E. Littlewood, to help him look at Ramanujan’s work. The two concluded that Ramanujan was indeed a genius. Hardy wrote back, noting that Ramanujan’s theorems fell into roughly three categories: results that were already known (or which could easily be deduced with known mathematical theorems); results that were new, and that were interesting but not necessarily important; and results that were both new and important. Hardy immediately began to arrange for Ramanujan to come to England, but Ramanujan refused to go at first because of religious scruples about going overseas.  However, his mother dreamed that the Goddess of Namakkal commanded her to not prevent Ramanujan from fulfilling his purpose. Ramanujan arrived in England in 1914 and began his collaboration with Hardy. In 1916, Ramanujan obtained a Bachelor of Science by Research (later called a Ph.D.) from Cambridge University. His thesis was based on highly composite numbers, which are integers that have more divisors (or numbers that they can be divided by) than do integers of smaller value. In 1917, however, Ramanujan became seriously ill, possibly from tuberculosis, and was admitted to a nursing home at Cambridge, moving to different nursing homes as he tried to regain his health. In 1919, he showed some recovery and decided to move back to India. There, his health deteriorated again and he died there the following year. Personal Life On July 14, 1909, Ramanujan married Janakiammal, a girl whom his mother had selected for him. Because she was 10 at the time of marriage, Ramanujan did not live together with her until she reached puberty at the age of 12, as was common at the time. Honors and Awards 1918, Fellow of the Royal Society1918, Fellow of Trinity College, Cambridge University In recognition of Ramanujan’s achievements, India also celebrates Mathematics Day on December 22, Ramanjan’s birthday. Death Ramanujan died on April 26, 1920 in Kumbakonam, India, at the age of 32. His death was likely caused by an intestinal disease called hepatic amoebiasis. Legacy and Impact Ramanujan proposed many formulas and theorems during his lifetime. These results, which include solutions of problems that were previously considered to be unsolvable, would be investigated in more detail by other mathematicians, as Ramanujan relied more on his intuition rather than writing out mathematical proofs. His results include: An infinite series for Ï€, which calculates the number based on the summation of other numbers. Ramanujan’s infinite series serves as the basis for many algorithms used to calculate Ï€.The Hardy-Ramanujan asymptotic formula, which provided a formula for calculating the partition of numbers- numbers that can be written as the sum of other numbers. For example, 5 can be written as 1 4, 2 3, or other combinations.The Hardy-Ramanujan number, which Ramanujan stated was the smallest number that can be expressed as the sum of cubed numbers in two different ways. Mathematically, 1729 13 123 93 103. Ramanujan did not actually discover this result, which was actually published by the French mathematician Frà ©nicle de Bessy in 1657. However, Ramanujan made the number 1729 well known.1729 is an example of a â€Å"taxicab number,† which is the smallest number that can be expressed as the sum of cubed numbers in n different ways. The name derives from a conversation bet ween Hardy and Ramanujan, in which Ramanujan asked Hardy the number of the taxi he had arrived in. Hardy replied that it was a boring number, 1729, to which Ramanujan replied that it was actually a very interesting number for the reasons above. Sources Kanigel, Robert. The Man Who Knew Infinity: A Life of the Genius Ramanujan. Scribner, 1991.Krishnamurthy, Mangala. â€Å"The Life and Lasting Influence of Srinivasa Ramanujan.† Science Technology Libraries, vol. 31, 2012, pp. 230–241.Miller, Julius. â€Å"Srinivasa Ramanujan: A Biographical Sketch.† School Science and Mathematics, vol. 51, no. 8, Nov. 1951, pp. 637–645.Newman, James. â€Å"Srinivasa Ramanujan.† Scientific American, vol. 178, no. 6, June 1948, pp. 54–57.OConnor, John, and Edmund Robertson. â€Å"Srinivasa Aiyangar Ramanujan.† MacTutor History of Mathematics Archive, University of St. Andrews, Scotland, June 1998, www-groups.dcs.st-and.ac.uk/history/Biographies/Ramanujan.html.Singh, Dharminder, et al. â€Å"Srinvasa Ramanujans Contributions in Mathematics.† IOSR Journal of Mathematics, vol. 12, no. 3, 2016, pp. 137–139.â€Å"Srinivasa Aiyangar Ramanujan.† Ramanujan Museum Math Education Centre, M.A .T Educational Trust, www.ramanujanmuseum.org/aboutramamujan.htm.

Silica Tetrahedron Defined and Explained

Silica Tetrahedron Defined and Explained The vast majority of minerals in the Earths rocks, from the crust down to the iron core, are chemically classed as silicates. These silicate minerals are all based on a chemical unit called the silica tetrahedron. You Say Silicon, I Say Silica The two are similar, (but neither  should be confused with silicone, which is a synthetic material). Silicon, whose atomic number is 14, was discovered by Swedish chemist Jà ¶ns Jacob Berzelius in 1824. It is the seventh most abundant element in the universe. Silica is an oxide of silicon- hence its other name, silicon dioxide- and is the primary component of sand. Tetrahedron Structure The chemical structure of  silica forms a tetrahedron. It consists of a central silicon atom surrounded by four oxygen atoms, with which the central atom bonds. The geometric figure drawn around this arrangement has four sides, each side being an equilateral triangle- a  tetrahedron. To envision this, imagine a three-dimensional ball-and-stick model in which three oxygen atoms are holding up their central silicon atom, much like the three legs of a stool, with the fourth oxygen atom sticking straight up above the central atom.   Oxidation Chemically, the silica tetrahedron works like this: Silicon has 14 electrons, of which two orbits the nucleus in the innermost shell and eight fill the next shell. The four remaining electrons are in its outermost valence shell, leaving it four electrons short, creating, in this case, a   cation with four positive charges. The four outer electrons are easily borrowed by other elements. Oxygen has eight electrons, leaving it two short of a full second shell. Its hunger for electrons is what makes oxygen such a strong oxidizer, an element capable of making substances lose their electrons and, in some cases, degrade. For instance, iron before oxidation is an extremely strong metal until it is exposed to water, in which case it forms rust and degrades. As such, oxygen is an excellent match with silicon. Only, in this case, they form a very strong bond. Each of the four oxygens in the tetrahedron shares one electron from the silicon atom in a covalent bond, so the resulting oxygen atom is an anion with one negative charge. Therefore the tetrahedron as a whole is a strong anion with four negative charges, SiO44–. Silicate Minerals The silica tetrahedron is a very strong and stable combination that easily links up together in minerals, sharing oxygens at their corners. Isolated silica tetrahedra occur in many silicates such as olivine, where the tetrahedra are surrounded by iron and magnesium cations. Pairs of tetrahedra (SiO7) occur in several silicates, the best-known of which is probably hemimorphite. Rings of tetrahedra (Si3O9 or Si6O18) occur in the rare benitoite and the common tourmaline, respectively. Most silicates, however, are built of long chains and sheets and frameworks of silica tetrahedra. The pyroxenes and amphiboles have single and double chains of silica tetrahedra, respectively. Sheets of linked tetrahedra make up the micas, clays, and other phyllosilicate minerals. Finally, there are frameworks of tetrahedra, in which every corner is shared, resulting in a SiO2 formula. Quartz and the feldspars are the most prominent silicate minerals of this type. Given the prevalence of the silicate minerals, it is safe to say that they  form the basic structure of the planet.

OLS estimation Assignment Example | Topics and Well Written Essays - 2500 words

OLS estimation - Assignment Example The respective means of these variables are 82.38, 80.77 and 44.66 and significant variability among the values taken by these variables is observed, implying a possibility that variations in attendance can potentially cause variations in marks. Other variables that can potentially affect performances in the course have to be accounted for to ensure a proper evaluation and so, â€Å"ability†, â€Å"age†, â€Å"hrss†, i,e., study hours are also explored. All these variables reflect strong variability and thus are all potential candidates as controls. (For details, see table 1 in appendix). Apart from simply looking at individual descriptive statistics, in order to obtain some idea about the interrelationships and potential causations, a table of scatter plots are also explored where â€Å"smarks† is the plotted as the y variable while â€Å"ability†, â€Å"age†, â€Å"hrss†, â€Å"alevelsa† â€Å"attl† as well as squared f orms of ability and attl as the x variables. From the plots (figure 2 in appendix), we find that both ability and its square seem to be positively correlated with marks. The variables â€Å"age† and â€Å"alevelsa† seem to have no associative patterns with marks. For attendance, our primary variable of interest, we find that there is evidence of clustering of values greater than the mean marks at the higher values of attl implying that higher lecture attendance rate is associated with better performances on average on the course. Further, it seems that there is some clustering at higher values of the squared lecture attendance rates. No correlation seems to be present between smarks and hrss from the last graph in the table. The interrelationships between these variables are important for regression specifications, since high correlations among independent variables may lead to multicollinearity. So, a scatterplot matrix is presented as figure 2 in the appendix. Theref ore, the summary statistics and the scatter plots, show that there is a strong possibility that class attendance influences performance along with other factors such as ability. Further, since some evidence of possible positive correlation between class performance as measured by â€Å"smarks† and the squares of â€Å"ability† and attendance, represented by â€Å"attl† were observed, the possibility of nonlinear dependence cannot be ignored. 2. Basic OLS estimation a) From the simple regression of smarks on an intercept and the variable â€Å"attl†, we find that attendance has a significant positive impact on performance1. The coefficient on attendance is close to 0.15 and has a t-stat value of 4.33>1.96, which is the 5% critical value for the t distribution under the null hypothesis that the coefficient is insignificant, i.e., is not statistically significantly different from zero. Additionally the intercept takes a value of 52.91 implying that the condi tional mean of â€Å"smarks† is 52.91 for students who have a zero attendance rate for lectures. This value is significant at the 5% level as well (t-stat value 19.06>1.96). However, the adjusted R-squared value is only 0.06 implying that only 6% of the variation of performance can be explained in terms of variations in lecture attendance rates. Therefore, the model fit is poor. b) Inclusion of ability and hours studied (hrss) leads to the impact of attendance rate falling to approximately 0.13 from 0.15, but the