Tuesday, December 24, 2019

America s Need For Black Gold - 1221 Words

Joseph Brickey Elizabeth Hantack Pre-AP English II 24 February 2017 America’s Need for Black Gold In 1973, in the wake of conflict in the Middle East, US drivers were feeling the repercussions with every gallon of gasoline and oil that they consumed. The members of OPEC placed an oil embargo on the US and several other nations because of their aid to the Israeli military. This embargo greatly pressured the US, who was highly dependent on foreign oil. In the aftermath of this crisis, President Nixon called for the increased energy production to avoid this problem in the future. Yet, in this present day, the United States faces a similar, although not as extreme, situation. Measures must be made to make the United States energy independent.†¦show more content†¦As of 2015, US natural gas proved reserves totalled 324.3 tcfg. The US produces 28.8 mmcfg (million million cubic feet of gas) each year (4). With unrestricted drilling of new sites, totalling 723 tcfg, the US could significantly increase its natural gas production per year in th e next 10-20 years (5). Body Paragraph 2 Domestic Production would create many jobs for citizens in rural communities Construction, alone, of the Keystone Pipeline will generate 42,000 jobs (2). As of January 2017, US oil and natural gas companies have employed 177,000 to produce, refine, and distribute oil products. By 2024, experts project the number to rise to 220,000, an almost 25% increase. Oil and natural gas companies hoping to drill unconfirmed sites in the United States will need to employ more and more people. (6). Hydrofracking and drilling are dangerous practices that could endanger the environment and workers. The US Department of Labor has recorded a steady decrease of work-related injuries and fatalities since 2012 and as of 2014, 120 work related fatalities have been recorded, 38% lower than 2013 (6). This decline in fatalities can be attributed to several factors, safer equipment, more safety regulations, etc. A new fracturing fluid used in the fracking process has been developed byShow MoreRelatedAfrican Culture : Africa Is A Mystery1378 Words   |  6 PagesMediterranean Sea and Europe with the Indian Ocean to the southeast and the Atlantic Ocean to the west. For most people, Africa is a mystery, a dream, a place often gives people unlimited reveries. where the dense lush tropical rainforest, the world s most vast expanse of the Sahara, there is quaint rough customs, as well as their rich flavor food. To me, before I really search African, I thought that the African countries are poor, are behind the modern. And when I searched the African culture, oneRead MoreLynching, Frederic Douglas and Black Women in Society1376 Words   |  5 PagesCan’t believe it’s already over. I know I didn’t say much but I can honestly say I’m grateful and I really enjoyed this class. 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After Black Elk got the gifts he was taughtRead MoreSummary Of Ellen Degeneres Essay1529 Words   |  7 PagesOn her award-winning talk show, The Ellen DeGeneres Show, Ellen talks with an eight-year-old boy, Demarjay Smith, whose dream is to become a personal trainer and to beat the Olympic Gold Medalist, Usain Bolt, in a race. Usain Bolt surprises Demarjay on the show and agrees to race him. Usain Bolt loses intentionally. The Olympics are a time for joy and celebration throughout a country; but after one post, this jovial time turned into something serious. Ellen DeGeneres, posted on twitter a â€Å"funny†Read MoreFree trade and Agriculture in the Global South 1491 Words   |  6 Pageswhile confirming Tony Weis argument that trade liberalization has entrenched an uneven playing field that disadvantages small farmers in developing countries. Only 20% of bananas are exported from poor developing countries and imported to North America, while cash crops, such as bananas, represent the largest source of income for developing countries. A major production limitation faced by these farmers is the management of watergrass (Commelina diffusa). This is a noxious weed that competes withRead MoreMusic Is The Greatest Singer Of The 20th Century1068 Words   |  5 Pagespeople from all around the world can find common ground between simple beats and rythyms. Music genres are built off of one another to develop new and unique genres, ranging from classical blues to heavy metal bands. In between the years 1960 and 2010 America has had over 13 diverse genres rule over musics Hot 100. Numerous talented artists have advanced music to what the world knows it as today. Frank Sinatra is one of the most well known and influential singers throughout the history of music, indisputablyRead MoreIr Theory And Rise Of The West1386 Words   |  6 Pagesthat the discovery of the Americas is the explicit explanation for the rise of European supremacy. Many factors brought me to this conclusion, which I will discuss throughout this entirety of the essay. First, we need to step back and examine Europe before the discoveries of the Americas. Secondly, I will discuss the numerous astronomical advantages in regard to what the discovery of the Americas meant for Europe. Lastly, I will discuss what the discoveries of the Americas meant for European supremacyRead MoreOppression in Diversity Essay1393 Words   |  6 Pagesdifferent cultures, and different skin colors has made people see diversity among each other. Diversity has caused people to kill, to conquer, and to destroy. The fact that diversity is apart of the United States of America has made this country as great as it is today. Diversity in America started in 1492 between the newly arriving Spaniards and the native Americans. When the natives saw these towering men they thought of them as gods for they had light skin and thundering beast called Horses. ButRead MorePolitical Background Should Be Mandatory1182 Words   |  5 Pagesposition meaning the Presidency. Voters and campaigners need to consider the political experience of those they choose to endorse. Because most of the responsibilities that come with being the President revolves around politics, it would be necessary to make having political knowledge mandatory. Without political knowledge, the future of the United States is in the hands of someone who simply has no idea what he or she is doing. President Ulysses S. Grant, for example, was elected into office afterRead MoreKill A Mockingbird, By Harper Lee1071 Words   |  5 PagesGeorge Washington once said, â€Å"I hope ever to see America among the foremost nations of justice and liberality†. While America has yet to reach an era where injustice is nearly or completely eradicated, we have most definitely progressed from the Great Depression in the 1930s and World War II. In World War II there was a black American fighter pilot group, named the Tuskegee Airmen, who suffered the racial prejudices of America despite fighting for America. Similarly, injustice is widespread in Maycomb

Sunday, December 15, 2019

Is costumer behavior a quantitative science or qualitativ Free Essays

Introduction All of us are consumers. We consume good everyday, we consume and buy products and services according to our needs, preferences and buying power. What we buy, how we buy, where and when we buy, in how much quantity we buy depends on our social and cultural background and our age and family but also on our perception, attitudes, beliefs and values, motivation, personality, and many other factors that are both internal and external to us. We will write a custom essay sample on Is costumer behavior a quantitative science or qualitativ or any similar topic only for you Order Now All this process is what we call in economics term consumer behaviour. It is important to say that we also consider before buying whether to buy or not to buy and, from which source or sellers. The marketers try to understand the needs of different consumers and having understood different behaviours require they study in their internal and external environment, they formulate their plans for marketing. I will try to develop an interdisciplinary approach of consumer behaviour starting from defining the concept moving to microeconomics methodological study and passing through the behavioural economics highly mphasizing on factors that influence the decision-making process of consumers behaviour I think two summarize more the concepts: â€Å"Customer behaviour reflects the totally of consumer decision with respect to the acquisition, consumption and disposing of goods, services, activities experiences, people and ideas by (human) decision-making†l . Customer behaviour means more than Just the way that a person buys tangible product such as cars. It also included peoples use of services, experiences and activities such as going to the doctor. Microeconomics and Behaviour economics I start with a brief overview of to microeconomics theory, which represents a starting point for examining costumer behaviour. The microeconomics theory makes the assumption that â€Å"Consumer behave rationally and given the chance they will choose the best alternative of with their level of income and preference2† Neoclassical economic coincided with the dominance of the positivist methodological position that judges a theory by its ability to make predictions that are supported by the evidence. In Microeconomics â€Å"the individual firm rationally maximizes profit through purchase decision†3. n sum the microeconomics theory balances tour elements tn consumer’s available income, the price of the goods, the consumer’s tastes or preferences, and the assumption of utility maximization. In such models, utility can best be thought of as levels of satisfaction, happiness or personal benefit. By using the assumption that individuals act in order to maximize personal subjective benefits, economists make costumer behaviour analyse quite simple as they â€Å"apply powerful mathematical techniques for modelling behaviour outcomes4†. The Microeconomics model of costumer behaviour often correspond to how costumer ehave however clear and voluminous evidence from psychology has shown that the rationality assumption of standards economics are wrong. Evidence from psychology has shown that we often are irrational. â€Å"This selfish maximization principle of Homo economicus limits the application of neoclassical economics to other areas†5 Recognition of these difficulties had led to a series of new approaches to modelling the individual behaviour, mostly based on challenges to the assumption of neoclassical economics. At the end of the 20th century the strict neoclassical position came under attack from many different directions. Some of these merely suggested more complex objectives and constraints, while others took economics is new directions by putting an emphasis on uncertainty and risk†6. Simon argued that human behaviour is best modelled as aspiration-based, rather than as optimizing behaviour. In his view is important to achieve aspiration levels with satisfactory outcomes indicating that â€Å"satisfy’ behaviour is normal and optimizing behaviour is abnormal. How to cite Is costumer behavior a quantitative science or qualitativ, Papers

Saturday, December 7, 2019

Philip Morris Essay Example For Students

Philip Morris Essay Complete Philip Morris Marketing Analysis Definition of Industry Market Concept The tobacco industry consists of many competitors trying to satisfy a specific customer need. Companies such as Philip Morris, RJ Reynolds, Brown and Williamson, and Lorillard hold almost the entire market share in the tobacco industry. While each company has different advertising and marketing techniques, they all target the same customer group. Tobacco companies try their best to generate interest in their particular brand or brands. Companies market a number of attributes that usually include, but are not limited to: taste, flavor, strength, size and image in order to distinguish themselves from competitors (Business Week 179, November 29, 1999). However, all tobacco companies are satisfying the same needs. Many long-time smokers are addicted to the nicotine in cigarettes. They smoke because the nicotine is needed to help them feel normal (Focus group). Many addicts go through withdraw without nicotine. All tobacco companies have nicotine in their cigarettes, which fulfills the need of long-time smokers. Other smokers depend on cigarettes in social settings. Many smoke to look sophisticated and mature. Tobacco companies make many kinds of cigarettes that target different groups. Social smokers may perceive certain brands as more sophisticated, and therefore they shy away from other lesser-known brands. For example, a person who smoked generic cigarettes at the bar may be perceived as uncultured. On the other hand, the smoker with the Marlboro Lights may be more socially accepted because they have a brand name product (Focus group). Many types of cigarettes cater to the many markets of smokers who want to portray a certain image in social settings. Tobacco companies do not create the need to smoke, but try to generate interest in their particular brand (Hays, New York Times, November 24, 1999). Overall, the tobacco companies satisfy consumer demand for the millions of adult Americans who choose to use tobacco by providing differentiated products to different target markets of smokers.Industry Concept The tobacco industry has developed a rather large array of products. Companies such as Philip Morris, Lorillard, RJ Reynolds, and Brown and Williamson, as well as the other smaller competitors, all provide the same product- cigarettes. The tobacco industry is filled with fierce competitors. But underneath the brand names and images, the product is relatively the same. All tobacco companies produce an inhalant that is made with tobacco, tar, and nicotine. These materials are rolled in a special kind of slow-burning paper for longer smoking time. The cigarettes are approximately three to four inches long and come in packs of twenty to twenty-five. With so many similarities, one would think that the market would resemble that of a commodity. However, through brand marketing and promotions, each cigarette is uniquely different in the mind of the customer. Boundaries The tobacco industry can be broadly or narrowly defined. Many products use tobacco as the main material. We chose to define the market by focusing on the tobacco and the way it is smoked. Companies such as Philip Morris, Lorillard, RJ Reynolds, and Brown and Williamson are the main competitors in the tobacco industry (Pollack, Advertising Age, August 30, 1999). They produce cigarettes, which are lit and the smoke is inhaled to the lungs. Tobacco products such as cigars, snuff, and chew are considered close substitutes to cigarettes. Cigar smoke is just taken into the mouth, but not inhaled like cigarettes. Snuff and chew do not even contain smoke, but are put on the skin for nicotine absorption. Companies such as Imperial Tobacco, which produce a wide array of chew and snuff products, would be considered a company that provides substitutes to cigarettes. .u6e1cc7769ebbfa324ce28c6fa878837a , .u6e1cc7769ebbfa324ce28c6fa878837a .postImageUrl , .u6e1cc7769ebbfa324ce28c6fa878837a .centered-text-area { min-height: 80px; position: relative; } .u6e1cc7769ebbfa324ce28c6fa878837a , .u6e1cc7769ebbfa324ce28c6fa878837a:hover , .u6e1cc7769ebbfa324ce28c6fa878837a:visited , .u6e1cc7769ebbfa324ce28c6fa878837a:active { border:0!important; } .u6e1cc7769ebbfa324ce28c6fa878837a .clearfix:after { content: ""; display: table; clear: both; } .u6e1cc7769ebbfa324ce28c6fa878837a { display: block; transition: background-color 250ms; webkit-transition: background-color 250ms; width: 100%; opacity: 1; transition: opacity 250ms; webkit-transition: opacity 250ms; background-color: #95A5A6; } .u6e1cc7769ebbfa324ce28c6fa878837a:active , .u6e1cc7769ebbfa324ce28c6fa878837a:hover { opacity: 1; transition: opacity 250ms; webkit-transition: opacity 250ms; background-color: #2C3E50; } .u6e1cc7769ebbfa324ce28c6fa878837a .centered-text-area { width: 100%; position: relative ; } .u6e1cc7769ebbfa324ce28c6fa878837a .ctaText { border-bottom: 0 solid #fff; color: #2980B9; font-size: 16px; font-weight: bold; margin: 0; padding: 0; text-decoration: underline; } .u6e1cc7769ebbfa324ce28c6fa878837a .postTitle { color: #FFFFFF; font-size: 16px; font-weight: 600; margin: 0; padding: 0; width: 100%; } .u6e1cc7769ebbfa324ce28c6fa878837a .ctaButton { background-color: #7F8C8D!important; color: #2980B9; border: none; border-radius: 3px; box-shadow: none; font-size: 14px; font-weight: bold; line-height: 26px; moz-border-radius: 3px; text-align: center; text-decoration: none; text-shadow: none; width: 80px; min-height: 80px; background: url(https://artscolumbia.org/wp-content/plugins/intelly-related-posts/assets/images/simple-arrow.png)no-repeat; position: absolute; right: 0; top: 0; } .u6e1cc7769ebbfa324ce28c6fa878837a:hover .ctaButton { background-color: #34495E!important; } .u6e1cc7769ebbfa324ce28c6fa878837a .centered-text { display: table; height: 80px; padding-left : 18px; top: 0; } .u6e1cc7769ebbfa324ce28c6fa878837a .u6e1cc7769ebbfa324ce28c6fa878837a-content { display: table-cell; margin: 0; padding: 0; padding-right: 108px; position: relative; vertical-align: middle; width: 100%; } .u6e1cc7769ebbfa324ce28c6fa878837a:after { content: ""; display: block; clear: both; } READ: Notes to Myself Essay They would not fall in the cigarette industry itself. 2 .Situation Analysis 2.1 Industry Structural Analysis 2. 1.1 Threat of Entry The tobacco industry has a very low threat of entry. A few powerful firms, such as Philip Morris, RJ Reynolds, Lorillard, and Brown and Williamson, control most of the industry (Pollack, Advertising Age, August 30, 1999). Any new entrants would be sure to receive heavy retaliation from the other companies fighting to keep their share of the lucrative industry. For example, Philip Morris is by far the industry leader with estimated tobacco sales of $46.7 billion

Saturday, November 30, 2019

Smart Materials in Aerospace Industry free essay sample

Within each subsection, we will draw a relationship between the properties of the smart material and its molecular mechanism. This is followed by presenting an outline of their recent and future applications, and the experimental procedures and results done in recent researches to show the feasibility of these applications. In the Discussion section, we will be delving into the cost-effectiveness and feasibility of using smart materials in aerospace components. Finally, the conclusion will give an insight into the relationship between the use of smart materials and the design of future aircrafts. 1. Introduction Smart materials are defined as materials that can significantly change their intrinsic properties (mechanical, thermal, optical or electromagnetic), in a predictable and controlled manner in response to their environmental stimulus[1]. In general, these materials can be categorized into 3 categories, namely thermal-to-mechanical (shape memory alloys), electrical-to-mechanical (piezoelectric), and magnetic-to-mechanical (magnetostrictive). Materials engineering has undergone a major transformation in the recent decade, as atoms and molecules are no longer viewed and worked upon on the microscopic level, but now on the nanometer level. We will write a custom essay sample on Smart Materials in Aerospace Industry or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page Materials requirements are becoming more complex, especially in the aerospace industry in which safety and cost-effectiveness often conflict against each other. It is no longer acceptable for materials to have a single function; they need to be multifunctional to save costs and weight. Smart materials are now replacing monolithic ones to achieve multiple functions at all scale levels. Hence, smart materials are essentially integrated into the use of aerospace components. What differentiates smart materials from normal monolithic ones? Smart materials exhibit characteristics which most scientists would term as ‘intelligence’. This includes immediacy (the ability to respond in real time); transiency (the ability to respond to more than one environmental states); self-actuation (inherent intelligence within material); selectivity (having a discrete and predictable response); and lastly, directness (response is local to the ‘activating’ event)[2]. The performance characteristics of aircrafts are often limited by properties of materials used in both the airframe and propulsion systems. With the recent advancement of materials technology, high performance materials are created, resulting in a breakthrough in the performance and efficiency of modern aircrafts. The discovery of smart materials provides cost-effective and innovative solutions to the limitations currently faced in the design of aircrafts. These smart materials perform specialized functions when exposed to external stimuli, and they are increasingly being used to replace conventional aircraft parts for better performance. In this report, we shall look at the current and future use of these smart materials in the aerospace industry. 1. Purpose The purpose of this report is to introduce the different types of smart materials and their applications in the aerospace industry. Recent and emerging uses of these smart materials will also be presented, with brief experimental procedures and results obtained from recent researches and experiments to show the feasibility in aerospace applications. 1. 2 Background Smart material transformation was first observed on gold-cadmium, and recorded in 1932. Five year later, in 1938, the same phase transformation was observed in brass. In 1962, Beehler and coworkers discovered the shape memory effects of Nickel-Titanium alloy, and they named this family of alloy as Nitinol. The discovery of Nitinol ignites the discovery of other alloy systems with shape memory effect, and also accelerates the use of smart materials in product development. [3] Since then, aerospace companies are also exploring the use of smart materials in aircraft components. Conventional automatic control systems which use servo-valve or hydraulic actuators face a lot of limitations. These limitations include multiple energy conversions, complexity due to large number of parts resulting in large number of potential failure sites and large weight penalty, high vulnerability of hydraulic network, and frequency limitation. In contrast, the advantages from the use of smart materials actuators include the direct conversion of electrical energy to high frequency linear motion, easier transmission of electrical energy throughout aircraft, and light and compact smart materials induced-strain actuation in place of bulky hydraulic power systems. With this huge potential offered by smart materials, researchers are eager to tap on this potential, by exploring on ways to implement these smart materials into aircraft components. 1. 3 Scope This report will present the 4 common types of smart materials that are popular in the market. A brief description will be made with regards to the mechanism of how the smart materials function. The properties of the smart materials will then be related to their current and future aerospace application. This is followed by the detailed outline of the experimental procedures undertaken by past researches, as well as results obtained which prove the feasibility of using these smart materials for the aerospace applications. Finally, discussions will be made on the viability of the use of smart materials in the aerospace industry, in terms of safety, cost feasibility and future trends. . Types and Applications of Smart Materials 1. Piezoelectric Material Piezoelectricity is the generation of electrical potential in a material in response to a mechanical stress. This is known as the direct effect. It can also mean mechanical deformation upon the application of electrical charge or signal (Harrison JS and Ounaies Z, 2001). In this case, the material can serve as a sensor to detect m echanical stress. In addition, the materials can serve as an actuator when there’s a large increase of size due to electrical stimuli. The two types of piezoelectric materials that are used as smart materials are piezoelectric ceramic and polymer. Properties Piezoelectric materials are widely used as they possess favorable properties such as fast electromechanical response, wide bandwidth, high generative force and relatively low power requirements (Harrison JS and Ounaies Z, 2001). In addition, piezoelectric polymers are flexible, lightweight, and have low acoustic and mechanical impedance, while piezoelectric ceramics are brittle, heavy and toxic. Mechanism Piezoelectric effect is formed in crystals that have no centre of symmetry. One end of the molecule is more negatively charged while the other end is more positively charged, hence a dipole moment exists within the molecule. This is due to both the atomic configuration of the molecule, and also the molecular shape. Polar axis is the imaginary line that runs through the centre of both charges on the molecule. The orientation of the polar axis determines the type of crystal. For monocrystal, all the molecules’ polar axes are oriented in the same direction (Figure 2. 1. 1), while for polycrystal, the polar axes of molecules are oriented in different direction (Figure 2. . 2) [pic][pic] Figure 2. 1. 1 Figure 2. 1. 2 To create the piezoelectric effect, polycrystal is heated under the application of a strong electric field. The high temperature increases the rate of self-diffusion among the molecules, while the strong electric field forces almost all of the dipoles to orient in nearly the same direction (Figure 2. 1. 3) [pic] Figure 2. 1. 3 Piezoelectric ef fect can now be observed in the crystal (Figure 2. 1. 4). Figure (a) shows the piezoelectric material in its neutral state. When the material is compressed, a voltage of the same polarity as the resultant dipole moment will appear between the electrodes (Figure (b)). Conversely, the voltage will be of opposite polarity when the material is expanded (Figure (c)). Similarly, a voltage applied that is opposite to the poling voltage will cause the material to expand(Figure (d)), while an applied voltage of the same polarity will cause the material to be compressed (Figure (e)). If an alternating voltage is applied across the material, the material will vibrate with the same frequency as the signal. [pic] Figure 2. 1. 4 Advantages and Disadvantages[4] Advantages |Disadvantages | |Compact and lightweight |Brittle due to crystalline structure | |Displacement proportional to applied voltage |Produce small strains compared to SMA and magnetostrictives | |Operate over large temperature range |Cannot withstand high shear and tension | |Fast response to applied voltage(msec) |Aging of material | |Repeatable sub-nanom eter steps at high frequency |Uses active control, which can result in instability | |No moving parts |Can become depolarized (at high temperature, high voltages and large | |Function at high frequencies |stresses) | |Excellent stability | | |Easily embedded into laminated composites. Aerospace Applications Piezoelectric materials are mainly used in the aerospace industry for shape control and vibration control. †¢ Tail-Buffet Suppression High performance aircrafts with twin vertical tails often face the aeroelastic phenomenon of tail buffeting, in which the unsteady vortices that emanates from the wing leading edge extensions burst and immerse the vertical tails in their wake. This results in severe vertical tail response and buffet loads, which lowers airframe life and increases maintenance costs. pic][pic] Before the development of piezoelectric actuators, various method of alleviating buffeting was used. One method was the use of hydraulic actuators to superimpose the oscillations of affected control surfaces about their hinges, so as to effect damping. However, this method has two disadvantages. Firstly, the flight control system and buffeting-minimization system must use the same degree of freedom for the same control surface, thus reducing the availabi lity of the control surface for each role. Secondly, operations are limited to low frequencies due to the difficulty of oscillation a large control surface about its hinges. Experiment The Technical Cooperation Program (TTCP) collaborated with National Research Council Canada (NRC) and Department of Defense of Canada (DND) in researching about the feasibility of using piezoelectric actuators for tail buffet suppression on a full-scale F/A-18. The full-scale aircraft was tested in the International Follow-On Structural Test (IFOST) Program rig in Australia (Yousefi-Koma A Zimcik DG 2003). The procedures for the experiment are as follow: †¢ The starboard fin of the aircraft was instrumented with piezoelectric actuators over a wide area on both sides of the fin, as shown in Figure 2. 1. 5. [pic] Figure 2. 1. 5 †¢ Accelerometers and strain gauges are placed strategically to measure displacements, and hence calculate the vibration amplitude. †¢ Electrodynamic shakers are attached to the fin to induce structural vibration. These shakers are controlled by the test rig control system to model actual flight structural loads. †¢ In the experiment, four custom-made high-power amplifiers of 2kVA rating over 200Hz bandwidth were used. Results Conclusion The experimental results have shown that the active control system using piezoelectric actuators was able to effectively suppress the buffet response of the vertical fin at high angle of attack. Amplitude reductions of up to 60% at the normal flight configuration and close to 10% in the worst case scenario were observed (Yousefi-Koma A Zimcik DG 2003). It was estimated even a small 10% reduction in vibration amplitude would double the durability of the fin. Hence, it can be concluded that with the use of piezoelectric actuators in active-control surface modal (ACSM) device to deform the control surface, the control surface not only can respond to buffeting-minimization signals, but also flight control commands. †¢ Wing Flutter Damping When a structure is placed in a flow of sufficiently high velocity, an aeroelastic self-excited vibration takes place, which has a sustained or divergent amplitude. This results in dynamic instability that can get violent. This is because at high speed, the effect of the airstream can cause the coupling of two or more vibration modes such that the vibrating structure will extract energy from the airstream. The extracted energy equals the amount of energy that the structure can dissipate at the critical speed, and a neutrally stable vibration exists. However, above this critical speed, the vibration amplitude will diverge, causing structural failure. Experiment and Result The Piezoelectric Aeroelastic Response Tailoring Investigation was conducted at MIT with the support of NASA, and it aims to achieve the following objectives: determining the power consumption of the piezoelectric actuators while controlling the response of the structure; investigating optimal piezoelectric actuator placement; and, testing disturbance rejection controllers at zero airspeed (Anna-Maria Rivas McGowan). The major components of the 4-feet test model, as shown in Figure 2. 1. , consist of two primary structures: an exterior fiberglass shell, which is used to obtain aerodynamic lift; an interior composite plate that contains the piezoelectric actuators, and is made up of an aluminium honeycomb core sandwiche d by graphite epoxy plates. The plates are of [20 °2/0 °]s laminate, referenced to the wings quarter-chord which is swept 30 °, and this provides a static coupling of the bending and torsional behaviour. Fifteen groups of piezoceramic actuators patches are placed at the top and bottom of the interior plate, and they are configured to impart moments to the plate. Together with the orientation of the graphite epoxy and the wing sweep angle, the actuators can affect bending and torsional vibration of the model. Forces on the model were monitored using ten strain gauges and four accelerometers. To acquire time history data, each of the 15 piezoelectric actuator groups was activated individually, as well as in five sets of several actuator groups. The experimental results is shown in the graphs in Figure 2. 1. 7. In summary, it shows that the control system can effect successful flutter suppression and gust reduction in the model, with a 12% increase in flutter damping and 75% decrease in root-bending moment caused by gusts. This clearly shows the potential of the use of piezoelectric actuators in suppressing the detrimental effects of wing flutter. Rotor Blade Twist Outboard portion of the blade travel faster, and with the same lift coefficient, higher lift force is concentrated near the blade tip. To distribute the lift force evenly among the blades, the angle of attack is made to be lower near the blade tip, and higher near the blade root, such that the lift coefficient decreases with increasing distance from the blade root. This can be done by induced blade twisting, through the embedment of piezoelectric materials into the blade skin. Active fibre composites (AFC) are actually used, which consists of continuous, aligned PZT fibres in an epoxy layer (Figure 2. 1. ), and copper electrode films that are etched into an inter-digitated pattern to effect the electric field along the fibre direction, as shown in Figure 2. 1. 9 (Rodgers and Hagood, 1998). [pic][pic] Figure 2. 1. 8 Figure 2. 1. 9 Experiment Active Fiber Composite (AFC) was fitted into the construction of a 1/6th scale replicate of CH-47D blade model (60. 619in span and 5. 388in chord). The blade was sent for wind tunnel testing at Boeing Helicopters, PA. Three AFC plies were diagonally placed in the co-cured D-spar blade lay-up. When the fibres are activated, it causes a shear in the spar skin, which creates the blade twist effect.

Tuesday, November 26, 2019

The Importance of Chemistry essays

The Importance of Chemistry essays We are surrounded everyday by Chemistry. Chemistry was responsible for you car to get you to work, your furnace to heat your home, and your body to turn your breakfast into energy. The coke you drank with your lunch was flavoured by chemistry. Chemistry is often called the central science, because it is vital in the sciences of physics and biology. For example a living organism is a complex chemical factory; by understanding the chemical behaviour scientists can find new ways to treat disease. Chemists have even made it possible to produce crops of food plants that are hardier than the parent strains. Chemists have been able to make lots of useful inventions by using their knowledge of Chemistry. They discovered by mixing some twenty odd chemicals together they could flavour something with the flavour of peaches with out that item of food coming in contact with a single peach. Blend together a few different chemicals and you can create a pleasant smelling liquid, thus revolutionizing the perfume industry. Chemists discovered certain compounds can be used as a non-toxic food perseverant. When we tan is the sun it is a chemical reaction between our skin and the UV rays of the sun. Chemists use their knowledge of the properties of this reaction to create effective sunscreen. ...

Friday, November 22, 2019

Analysis Of Hamlets Isolation English Literature Essay

Analysis Of Hamlets Isolation English Literature Essay Many works reveal existentialism as a philosophy towards life. Someone who believes in this philosophy tends to become lonely, as one of the key concepts of existentialism is that we are alone. As demonstrated in Shakespeare’s tragic play, Hamlet’s attempt to come to terms with his existence pushes him to the edge as his loneliness overwhelms him. His soliloquies show elements of existentialism, revealing his turmoil of spirit and developing his character as being increasingly isolated. In Hamlet’s speeches, we see that he is an existentialist. When the ghost appears to Hamlet of his father passed, Hamlet is horrified. This encounter further pulls Hamlet away from reality as the ghost fills his head with ideas and a mission; Hamlet will revenge his father and kill Claudius. Claudius is revealed to us as being a hostile social force when the ghost comments, â€Å"The serpent that did sting thy father’s life / Now wears his crown.† (1.5.39-40). He re fers to his murder being committed by Claudius, Hamlet’s uncle. Hamlet admits that â€Å"à ¢Ã¢â€š ¬Ã‚ ¦memory holds a seat in [his] distracted globeà ¢Ã¢â€š ¬Ã‚ ¦Ã¢â‚¬  and that he must â€Å"à ¢Ã¢â€š ¬Ã‚ ¦wipe away all trivial fond records, / all saws of books, all forms, all pressures past, / That youth and observation copied there;à ¢Ã¢â€š ¬Ã‚ ¦Ã¢â‚¬  (1.5.97-102). By this, Hamlet means that he must do something about his life path and not dwell in the past. This resolve suggests the importance of the present. Hamlet is aware of the importance of acting on his impulses now because he realizes that something like pain can be easily forgotten. He wants the revenge to be as meaningful as possible to exact his vengeance properly. Estrangement from oneself can occur in many different forms. Hamlet’s thoughts and actions are disconnected. His mind is telling him to take revenge and kill Claudius, but his body does not obey him. He is in constant turmoil and contra diction with himself which brings him to be separated in his intentions versus his operations. This estrangement is disadvantageous to Hamlet in completing his task. Hamlet chastises himself for his failure and procrastination in regard to his father’s murder. In the observation from another of Hamlet’s soliloquies, â€Å"The spirit that I have seen / May be the devilà ¢Ã¢â€š ¬Ã‚ ¦. Out of my weakness and my melancholy, / [He] abuses me to damn me. I’ll have grounds / More relative than this. The play’s the thing / Wherein I’ll catch the conscience of the king.† (2.2.596-603) Hamlet doubts his father’s ghost’s credibility and is further isolated from those around him. His resolve makes him focused on this mission and Hamlet’s relationships with others suffer. The relationship with Claudius was already on edge, but Hamlet pushes him even farther away as he plots to kill him. The famous quote â€Å"To be, or not to be: t hat is the questionà ¢Ã¢â€š ¬Ã‚ ¦Ã¢â‚¬  (3.1.57) reflects on the human condition. Hamlet views the world in a different way than the other people around him. He realizes that people are alone and that things are not always as they seem. His insight scares and baffles other characters who interact with him. This is why Ophelia is also pushed away as Hamlet struggles with his inner turmoil and isolates himself from not only his mother and new king, but his girlfriend and love interest as well. This also reveals the absurdity of life. At this point in the play, Hamlet’s madness is being contributed to rejection of Ophelia’s love. This absurdity is only revealed to the readers of the play who have insight into Hamlet’s mind and intentions through his emotional soliloquies. The absurdity is further shown as Hamlet reflects on ending life. He describes the relief of dying, of leaving this world of pain and discomfort. However, one can never know what follows death a nd the fear of this prevents us from finishing ourselves off without living as much of this life that we can. Hamlet’s observation of this human condition remains absurd in our belief in it and our willingness to hold on to what we know.

Wednesday, November 20, 2019

What legal protection is given to archaeological sites in Britain To Essay

What legal protection is given to archaeological sites in Britain To what extent are these measures effective in safeguarding their future - Essay Example ise in order to preserve the heritage of the country because it understands that it is the only evidence of the pre-historic periods that existed and ensures that the legislation to meet these needs are properly carried out. The Ancient Monument Protections Act of 1882 was first imposed by the British parliament as a protective measure for all archaeological sites in Britain. The sites include ancient buildings, monuments, caves etc. The Protection for Military Remains Act of 1986 takes care of vehicles, vessels and other aircraft. The Archaeological Heritage Management also known as the Archaeological Resource Management is instrumental in conserving and managing the ancient archaeological sites of Britain. Their chief focus relates to the preservation, age and the use of the different archaeological resources available to us. In lieu of modern planning and development that poses a threat to the archaeological sites, the Archaeological Source Management Department devise ways and means of mitigating the adverse impact it could have on archaeological sites. In assessing the physical condition of any archaeological site, modern methodology and techniques are used to analyze, monitor and document the exte nt of deterioration and try to find the best means to preserve or conserve these ancient sites. In this essay we will attempt to look at the legislation that governs the conservation of archaeological sites and monuments so that we gain a better understanding of how important such laws are to the cause of preserving them. In Scotland alone, there are about 70,000 monuments and sites that are presently preserved under the Ancient Monuments and Archaeological Areas Act 1979. The Secretary of State for Scotland plays a major role in the planning system. The local authorities are also responsible for the preservation and safeguarding of such archaeological sites and contribute towards the economy by helping with landscaping and other amenities for development of