The Importance of Education Essay Example | Topics and Well Written Essays - 2500 words

The Importance of Education - Essay Example So second thing to look for is the fee structure and the scholarship facilities, not every student can pay high fees that mostly good universities ask for so they apply for scholarships which are mostly need based or on high academic records of the students. So a mediocre student who is not financially stable and does not have a sound academic record can not avail the facility of studying at high reputed universities (Runciman, 2009). Then what is left is the infrastructure of a university if that is well formed and is feasible for a student to adapt. So a university should then be evaluated on the basis of the facilities it is providing to the students such as transport, building and communication system among the management and the students. Location of a university also matters a lot while deciding because mostly students prefer the universities in their home town or nearby location to avoid the cultural shock, cost of living, daily life facilities such as nearby shopping stores, bank and the accommodation issues which can be a great nuisance for students (McChesney, 1999). Some students also opt for the universities abroad again they have to go through all the above process of evaluation for selection one of the thousands of universities (Kaplan, 2003). Advertisements of these universities play a vital role as they create awareness among the students in other countries of their existence and the facilities they provide so that students do not have much problem researching about these universities, their repute, fee structure, infra structure and scholarship facilities (Johnson, 1978). After evaluating all the factors mentioned above a student may choose the university that is highest on the feasibility... As the paper declares  mostly students from their very early student life choose a field of interest and from there the process of university selection starts and when it is about time they have sorted out which university is best for them but still there are students who have a pool of choices around them and it is really hard for them to pick just one. So they start evaluating among the pool of universities on the basis of their infra structure, popularity, fee structure, scholarship facilities, location and advertisement.This essay stresses that availability of accommodation and the employability of an institute remain to be the most important factors which help students in decision making. All of the students study hard to reach Master’s programme level and they definitely want to get a surety about future employment and that is why this information plays a vital role in decision making. In reply to the third question that if the students know that Nottingham Trent Unive rsity (NTU) offers scholarships or not, the respondents have said that majority of them know about the scholarship offered by NTU before entering the university. 23 out of 30 claimed that they knew about the scholarship offering by NTU. 7 participants said they did not know about it.  When the 30 participants were asked about the ranking of universities, a clear majority of them agreed that they would like to go to better ranked universities.

Everyday language and everyday life Essay Example | Topics and Well Written Essays - 1000 words

Everyday language and everyday life - Essay Example Oh my gosh, I’m a dork, shoot me. Laughing out loud†¦ â€Å"See you at the bar for pizza tonight!† Obviously, no parent, from his or her perspective, could interpret that perfectly! The preponderance for jargons or acronyms for texting and emailing came as a natural consequence of the need for speed in communicating messages across various medium. Further, since cell phones have virtually minute screens to contain long words and complete sentences, people who are in a hurry to send instant messages creatively designed messages in shorthand. Even businesses need to be apprised of these jargons and abbreviations to answer messages coming from diverse stakeholders. A secretary behind closed door meeting could instantly text: PEBCAK to her colleague to mean Problem Exists between Chair and Keyboard – to which the recipient could reply: FYI I’m OTP (for your information, I’m on the phone). With the basic objective of increasing the speed by which messages are sent and delivered, the emergence of abbreviated words came as a necessity and as a form of creative expression. Does it really have a negative effect on children in terms of literacy and correct usage of the English language? While viewing it’s Only a Theory from You Tube, an interesting proposition was being defended by David Crystal, a professor of linguistic from Bangor University, that â€Å"texting is good for the English language†. He disputed several myths, one of which is that kids use abbreviations in texting which leave letters out affecting their knowledge to spell. Likewise, these abbreviations continue to be used in essays and examinations which mean that adults are rearing this generation of kids that are totally illiterate. The funny thing is that Professor Crystal concluded the contentions my saying that these are all a load of chicken droppings. Texting, with all its abbreviations, when used frequently is

BP Global: Future Strategy Sustainability

BP Global: Future Strategy Sustainability British Petroleum (BP) is the worlds one of the largest and leading petroleum product manufactures. It has headquarters in London. It operates from 29 countries. Though it has faced safety and environmental controversies in the history of its operations it could overcome all negative images through a concrete focus and consistent efforts towards sustainable developments. BP operates throughout the world in locations, terrains and climates that are tremendously diverse and frequently challenging. However, BP aims to minimize its environmental impact by taking a systematic and disciplined approach to operations, using sophisticated risk assessment techniques that directly inform its business plans. Therefore, BP is incorporating its environmental management systems into the group-wide operating management system that helps BP to set priorities for operations based on assessment of the key risks, including those related to environmental and social performance. BP believes this integration will promote greater efficiency and consistency across the business. It has formulated a set procedure to conduct, at least annually, a formal process to identify and assess risks and emerging issues, including environmental and social issues. Main aim of BP is to manage environmental and social risk during every phase of its operations viz. launching new projects, carrying out day-to-day operations and bringing a project to a close. BP strives to minimize the impact on the environment by identifying risks during the project set-up and using technology to reduce or remedy any impacts. The firm is investing in a broad portfolio of alternative energy businesses and RD, while advocating a carbon price and public funding to support such new technologies. The firms greenhouse gas efficiency achievements will be vulnerable to a shift towards unconventional fossil fuels. Climate change creates both threats to BP through market changing technologies, and opportunities, such as increasing natural gas sales at the expense of coal. BP partly manages these risks by applying an internal carbon price to new projects and through its policy influence. Through its clean energy investments BP is hedging against dramatic changes to the worlds energy mix. In this assignment, we have taken up the BPs sustainability report of 2009 and studied its activities enabling it to achieve sustainable growth. We also assessed its capabilities, current position and forecast its future sustainable growth. British Petroleum Limited (BP) Introduction Website: http://www.bp.com Location of Headquarters: 1 St. Jamess Sq., London, SW1Y 4PD, United Kingdom Sector Industry: Basic Materials Energy Nature of Business: Oil Natural Gas Business Wind Solar Energy Business Bio-fuel Business Energy Security Energy Diversity Business Technology Partnership Products: BP petroleum and derived products BP service stations Air BP Aviation Fuels Castrol motor oil ARCO gas stations am/pm convenience stores Aral service stations solar panels Historical Background: BP (NYSE:BP) is one of the worlds largest oil and gas companies in terms of production capacity. In 2009, the companys exploration and production segment produced approximately 2.53 million barrels of oil per day as well as 8.48 million cubic feet of natural gas per day while the companys refining throughput averaged 2.28 million barrels/day. BP expands its production capacity through improved rig equipment and technology as well as expansions into other countries. As of April 2009, BPs operates in 29 countries including Mexico, Russia, Algeria, and many others in the Middle East and Africa. While BPs global reach gives the company an ability to access untapped reserves, many of its operations are exposed to political risk in those countries. In particular, BPs Russian operations faced significantly managerial problems in 2008, but these tensions eased in January 2010 with the appointment of Maxim Barsk to CEO. BP has been involved in a number of environmental, safety and political controversies during its history, including the 1965 Sea Gem incident and the 2010 Deepwater Horizon oil spill. Its primary listing is on the London Stock Exchange and it is a constituent of the FTSE 100 Index. It has a secondary listing on the New York Stock Exchange. BP on the Sustainability: Before we predict BPs position in future, let us first have look in to its present position and future plans for protection of environment, commitment to society and efforts towards economical growth and sustainable development. Present: BP operates responsibly with better corporate governance and management systems. BP strives to deliver secure and affordable energy while addressing the global issues and climate change. Efforts are made to develop large scale business towards the production of alternative energy sources with low carbon emissions. BP has given utmost importance to safety reliability of operations. But the accidents and fatalities have not been on reducing trend, which can have a major impact on it sustainable growth. BP focused on low carbon or green house gas emissions, biofuels, and operations that can emit fewer pollutants. People Management: There is clear focus on training development of the workforce and reward and recognition system but there is no clear evidence of integration of people development with its diversified business requirements. Community Initiatives: BP has made efforts to build a strong mutually beneficial relation with society wherein they work. Future Plans: In BPs business strategies especially for the sustainable growth, there are many ways forward, but certain parameters are clear. The response must be integrated, global and balanced in terms of social, economic and environmental solutions. BP plans to focus on major public policy issues such as climate change, environmental protection and human rights. The future plan is to show that everything that is done, and every product and service that are provided, is delivered in an environmentally and socially sound manner. The challenge is to adapt, to become more sensitive to the wider world with change in environment. The future plan mainly boils down to the environmental protection and economy growth. BP needs to integrate its future strategies in all its business units to bring the transparency for verification against a common factor on a single platform. There is a clear focus on developing value leaders in future with strong HR strategies. The focus is more on integrating the HR policies across its operations to improve the skills and knowledge of the people. IT must also help BP to develop future leaders who can be visionary to achieve sustainable growth. Even though future plans of BP clearly focus on economy development, workforce development and environmental excellence but the community development appears to be in the last bench of the agenda as the concrete evidence of plans to reach Phase 4 or 5 of the sustainability model is not available with respect to community development. BP Today: Today BP displaying the following characteristics: Systemic plan to integrate human resource functions to reduce cost/increase efficiency Focus on value add training/development opportunities i.e. waste reduction, lean principles Undertakes community projects where cost-benefit can be exemplified. BP The Good Days By the early 1990s, a newly envisioned BP appeared to be adopting a strategic approach (Phase 5) towards sustainability. Like its competitor Shell, BP too strategically placed itself to move beyond petroleum. It committed itself in inventing alternative energy sources and technologies. It also committed itself to the Kyoto Protocols and greenhouse gas emissions. BP also ventured into social and community sustainability efforts, working towards enhancing the efforts in the respective local communities. These efforts were incorporated to its corporate strategy as part of five broad spectrum of business policy: ethical conduct, employees, relationships, health, safety, and environmental performance, control and finance. BPs vision was to market itself as the greenest fossil fuel producer in the industry: Their Beyond Petroleum won two PR Week campaign of the year awards and the gold Effie from the American Marketing Association. Ogilvy, the firm behind the slogan ironically still boasts of Beyond Petroleum as a successful case study in its website. BP CSR Disaster: Unfortunately for BP, the carefully marketed CSR plan went awry with the gulf oil spill. The oil spill taught the world rather brutally, that the heart of the relationship between BP and society did not lie in honest commitments. Chastened by the Exxon Valdez disaster, BP along with every player in the oil industry became rather religious on CSR initiatives. CSR actually poses a problem in such a situation in that it muddies the waters. Beyond Petroleum, the marketing campaign was the result of painstakingly long plan spread over years-but that was all it was, a carefully constructed marketing plan for external stakeholders that suggested CSR was at the heart of BP, but did little to show any evidence of it. BPs isnt out there to lead the green revolution. Their actual business is to make money for its shareholders; in BPs case by producing energy, mainly from fossil fuels. Today, not only has their motto come under external pressure, but has also instigated soul-searching within BPs ranks. Todays marketplace demands a lot more from corporations to establish long term sustainability. It should begin with a basic principle: A successful company must embrace corporate responsibility in all its forms-both internal and external. While BP did an excellent job externally for many years (see Sustainability Portfolio below), it requires much more in-depth introspection from management to get the internal vision re-aligned. Strategies of BP Today BP has a sound platform on which to achieve their commitment to combine growth with the discipline of performance and strategies. So the concept of sustainability is already part of business today. But it also demands a deeper, broader, more creative level of engagement than conventional environmentalism. Climate Change, demographic change and poverty are the three major trends that will set the corporate sustainability worldwide The BP has challenge to create a future energy mix that meets three of these objectives sufficiency; security; and sustainability of the energy. But there are hard political choices involved in agreeing to cut emissions and accepting the implications for energy. The company drives the necessary innovation or deployment of emerging low carbon technologies in the operation. In the drive for efficiency, BP will collaborate with the vehicle manufacturers on advanced engine technology and lubricants and provide better and cleaner transport fuels through less energy intensive processes and increase the energy efficiency of their facilities and equipment BP was the first energy company to be widely recognised as accepting the obligation to act on climate change. They have invested nearly $4bn in low carbon business since 2005 and commitment to invest $8bn in alternative energy in coming years. BP are creating long-term options for the future in new energy technology and low-carbon energy businesses. They will be also enhancing capabilities in natural gas, which is likely to be a vital source of relatively clean energy during the transition to a lower-carbon economy and beyond. BP will utilize the best talent inside and outside the company to develop and apply the technology associated with their business challenges. They have the right people in the right places with the right skills. They have developed a new leadership framework and extensive training programmes to build the professional skills of employees, BP will focus on operations and fostering a culture of operational excellence and continuous improvement across all their activities. BP is a diverse and inclusive company where everyone can achieve their potential. BP will be able to demonstrate clearly how technology improves performance and improve the safety factor. BP will able to reduce its hydrocarbon emissions to water and hydrocarbon emissions to air, the burning of waste gas, carbon dioxide emissions, emissions of non-greenhouse gases, such as nitrogen oxides and sulphur oxides significantly.. BP will be using its landholdings as a base for solar generation of electricity. BP focus is on four key businesses: biofuels, wind, solar and carbon capture and storage. Their goals are no accidents, no harm to people and no damage to the environment. Company will work to achieve this through consistent management processes, ongoing training programmes, rigorous risk management and a culture of continuous improvement. Community development must be focused on BP as an integral part of CSR rather than initiating just as a compensatory act for the damage caused to public and environment. As a company with extensive operations in developing nations, some whose BPs own revenues surpass, it needs to carefully manage aspects such as human rights approach and maintaining ethical business practices. BP would be stick with its commitments towards safety concerns, security, safe operations and accountability in all the locations. BP shall plans to further improve operating and cost efficiency right across the company, from refineries and marketing operations in the downstream to procurement, drilling and project management in the upstream efficiency and reduce costs for profit growth. BP will develop the culture of innovation in all their operations. BP continues to access new business opportunities, with new agreements in other countries. To increase its financial flexibility, BP shall plans to reduce its debt, now about $23 billion, to $10 billion within 18 months. BP has to establish new ways of communication with all stakeholders to improve the brand image and reputation across the globe. BP shall view the corporate governance as a strategy for long run sustainable growth and survival. They should also ensure that board should be structured appropriately to ensure the implementation of rules, regulations, ethical, moral principles and obligation in all activities. It is essential to achieve high standards in all three elements of the triple bottom line agenda economic, environmental and social performance. Focusing on any one at the expense of the others is not sustainable. BP shall build competitive advantage by procuring and multiplying resources create abilities over them and developing synergy of resources and capabilities. Core competencies enable BP to formulate strategies and draw strategic action by converting competencies into profitable business activities. Suggested Future Strategic Concepts for BP: BP should plan to re-conceive its product portfolio and the market it is being catering to till date. Taking a holistic view of the market, BP should mould the goods to cater to the energy needs of the community and not just oil or natural gas. Presently BP defines its productivity by production rate i.e. MT/annum. However, we would suggest that real productivity of BP product can happen when the firm follows up its product till its life cycle. It has already started activities in this direction by entering into strategic alliance with vehicle manufacturers. But it needs to take shape. Actual productivity definition for BP should be Amount of energy converted to actual use by the community per MT of fuel provided by BP. Say for example a Diesel Engine operated by Heavy Fuel (a product of BP) operates at about 30 to 35% efficiency. 10,000 Kcal of Energy provided by the oil is converted to just 3500 Kcal of another form of energy which again is not utilized to 100%. Hence BP should redefine productivity so that the benefit is directly transferred to the community. Such activity would be a win-win situation from BP as well as society at large. BPs one of the strategic management thoughts should be to secure its own future competitiveness. Given the finite life of natural fossil fuel, BP should start its activities in thinking differently on each different use of fuel. Let us take an example of transportation. All vehicles use fossil fuel. Scientists have already come out with hybrid cars, solar cars, compressed air cars, etc. BP should actually go a big way in developing Anti Gravity Cars. We all see UFOs and Flying Discs, etc. Can this earth not produce such vehicles? This is no fancy idea, BOAC have a specific RD drive for such vehicles. They already have achieved some success lifting about 3gm material. Ultimately, we aim at developing competencies by BP in a wider scope of business which would then not get jeopardized due to depleting finite resources. Improvement in Corporate Governance has to reinstate the confidence in community which has shaken up due to past disasters. The pace of expansion activities has overshot the governance speed. Here comes the role of strategic leadership. Two of the key qualities of an effective leader are to anticipate and envision. BP needs to provide more stress on these two aspects. We are aware that as and when there is a need, the fossil fuel prices are raised and there is no one to question them. BP should analyze in further details as to what extent the suppliers contribute to the competitive dynamics of oil business (this is one of the key pillars of the Porters 5 force model and extremely relevant one for BP). A simple coordination between the oil rig, VLCC and met department can effectively reduce cost to BP substantially. Many times this is not done because there is no stringent specific target or cap on total cost of product/MT. This effort will not only help BP outperform its competitors, but also can pass on the benefit to the customers for benefit of the community.

The Portrayal of Gabriel Oak in Far from the Madding Crowd by Thomas Ha

In the novel Far from the Madding Crowd written by Thomas Hardy, I will be observing in detail the main character, Gabriel Oak, a young sheep farmer. I am going to determine how he is described as a heroic character in the first seven chapters. Gabriel Oak is portrayed to the reader as a heroic character in several different ways. In chapter one, there is no action or events. Alternatively, in the first paragraph, there is a description of Oak, which is mainly focused on his broad smile. His smile is compared using a simile, 'like the rays in a rudimentary sketch of the rising sun.' This immediately implies that he is a cheerful, good-natured character. Secondly, he is referred to with many different names. Farmer Oak illustrates his status, respect and authority. His Christian name, Gabriel has a reference towards the bible, as Gabriel was the good angel of God. Lastly, his surname, Oak, this may refer to wood as Oak is strong and durable which may represent his strength and durability. This is stressing the positive quality of Oak's character. The reader starts to get an encouraging image of Gabriel once reading the first two paragraphs. Farmer Oak's background is rather straightforward although he has had many jobs. He is conscientious and thorough as he cares greatly on how everything is presented and what people think of him. He was firstly a shepherd and then a bailiff before becoming a farmer. His father was a shepherd, so he had grown up on a farm learning the skills required from his dad. Moreover, the clothes Gabriel wore were not pretentious. I know this because on his working days he wore his clothes ... ...ently told everybody what had to be done to help and soon the fire was under control. Without Gabriel's good sense and bravery the fire would have been unmanageable. Oaks courage was admired by all of the spectators and many compliments soon spread through the crowd. Once Gabriel had found out that Bathsheba was in need of a shepherd, he was not too modest to ask her. He did not let what happened in the past effect his decision in asking her for a job and did not seem embarrassed. This shows his respect towards people and shows that he is a highly regarded man. All these positive qualities show that Gabriel Oak is a reputable man and is willing to help anyone, even if he does not know them. It shows that he is courageous and not a proud man. All of which portray to the reader that Gabriel Oak is a heroic character.

Pressure Measurement and Calibration

52 PRESSURE MEASUREMENT AND CALIBRATION (TH2) 53 EQUIPMENT DIAGRAMS 54 55 56 EQUIPMENT DESCRIPTION Refer to the drawing on pages 56, 57 and 58. This equipment is a bench top unit designed to introduce students to pressure, pressure scales and common devices available to measure pressure. The equipment comprises a Dead-weight Pressure Calibrator to generate a number of predetermined pressures, connected to a Bourdon gauge and electronic pressure sensor to allow their characteristics, including accuracy and linearity, to be determined. The Dead-weight Pressure Calibrator, Bourdon gauge and pressure sensor are mounted on a common PVC base plate. The electrical console is free standing. The Dead-weight Pressure Calibrator consists of precision ground piston (10) and matching cylinder (11) with a set of weights (12). In normal use the appropriate combination of weights is applied to the top of the piston, to generate the required predetermined pressure, and then the piston is set spinning, to reduce vertical friction, while the readings from the measuring devices are recorded. The operating range of the Dead-weight Pressure Calibrator and instrumentation is 20 kNm-2 to 200 kNm-2. The Bourdon gauge (5) and pressure sensor (6) are mounted on a manifold block (2) with a priming vessel (4) to contain the hydraulic fluid which is chosen to be water for safety and ease of use. A priming valve (7) between the reservoir and the manifold block allows the cylinder, manifold block and gauge on test to be easily primed with the water ready for use. A damping valve (8) between the cylinder and the manifold block allow the flow f water to be restricted to demonstrate the application of damping. An additional isolating valve (9) on the manifold block allows water to be drained from the manifold block or allows alternative devices to be connected for calibration. Such devices can be tested over the range 20 kNm-2 to 200 kNm-2. The Bourdon gauge (5) supplied is a traditional industrial instrument with rotary scale and mechanical indicator. The gauge has a 6† diameter dial that incorporates an arbitrary scale calibrated in degrees of rotation (independent of unit pressure) in addition to the usual scale calibrated in units of kNm-2. A clear acrylic front face allows observation of the Bourdon tube the mechanism that converts motion of the Bourdon tube to rotation of the indicator needle. The electronic pressure sensor (6) supplied incorporates a semi-conductor diaphragm that deflects when pressure is applied by the working fluid. This deflection generates a voltage output that is proportional to the applied pressure. The pressure sensor should be connected to the socket (20) marked ‘Pressure Sensor’ on the front of the console. The power supply, signal conditioning circuitry etc are contained in a simple electrical console (15) with appropriate current protection devices and an RCD (26) for operator protection. The electrical console is designed to stand alongside the Dead-weight Pressure Calibrator on the bench top. All circuits inside the console are operated by a main on/off switch (16) on the front of the console. 57 The various circuits inside the console are protected against excessive current by miniature circuit breakers, as follows: CONT (27) O/P (28) This breaker protects the power supply and circuits inside the console. This breaker protects the electrical output marked OUTPUT (23) at the rear of the console. The socket is used to power the IFD3 interface used for data logging. The voltage from the pressure sensor is displayed on a digital meter (17) on the electrical console. An additional conditioning circuit incorporates zero and span adjustments and allows the voltage output from the pressure sensor to be converted and displayed as a direct reading pressure meter calibrated in units of pressure. The zero control (21) and span control (22) are mounted on the front of the console for ease of use. A selector switch (18) allows the voltage from the sensor or the direct reading pressure reading to be displayed as required. The voltage from the pressure sensor is simultaneously connected to an I/O Port (19) for the connection to a PC using an optional interface device (TH-IFD) with educational software package (TH2-303). Alternatively, the signal can be connected to a user supplied chart recorder if required. Before use, the priming vessel must be filled with clean water (preferably deionized or demineralised water) and the calibrator, Bourdon gauge and pressure sensor fully primed. 8 OPERATIONAL PROCEDURES This equipment has been designed to operate over a range of pressures from 0 kN/m2 to 200 kN/m2 may damage the pressure sensors. In order to avoid such damage, DO NOT APPLY CONTINUOUS PRESSURE TO THE TOP OF THE PISTON ROD WHEN THE PRIMING VALVE IS CLOSED except by the application of the masses supplied. An impulse may be applied to the piston when operating at a fluid pressure of less than 200 kN/m2. This procedure is described in Experiment P1. The following procedure should be followed to prime the Dead-weight Calibrator and pressure sensors, prior to taking readings: Level the apparatus using the adjustable feet. A circular spirit level has been provided for this purpose, mounted on the base of the dead-weight calibrator. Check that the drain valve (at the back of the Bourdon gauge base) is closed. Fill the priming vessel with water (purified or de-ionized water is preferable). Open the damping valve and the priming valve. With no masses on the piston, slowly draw the piston upwards a distance of approximately 6 cm (i. . a full stroke of the piston). This draws water from the priming vessel into the system. Firmly drive the piston downwards, to expel air from the cylinder back towards the priming vessel. Repeat these two steps until no more bubbles are visible in the system. It may be helpful to raise the central section of the return tube between the manifold block and the priming vessel. This will help to prevent air be ing drawn back into the system as the piston is raised. Raise the piston close to the top of the cylinder, taking care not to lift it high enough to allow ir to enter, and then close the priming valve. The following procedure describes the calibration of the semiconductor pressure sensor. The procedure differs if using the optional TH-303 software, in which case users should instead refer to the Help Text provided with the software. Remove the piston from the cylinder, and switch the selector knob on the console to ‘Pressure’. This the ‘zero’ control on the console until the display reads zero. This sets the first reference point for the sensor calibration. Return the piston to the cylinder, and reprime the system as described above. Place all the supplied masses onto the piston, with the greatest mass (2 ? kg) being added last. This corresponds to an applied pressure of 200 kN/m2. Spin the piston, and adjust the ‘span’ control until the sensor output matches the applied pressure. This sets the second reference point for the calibration. 59 The calibration may be tested by applying a mass to the piston, spinning the piston in the cylinder, and then comparing the applied pressure to the sensor output. Each ? kg of applied mass corresponds to 20 kN/m2 of applied pressure. This piston itself gives an applied pressure of 20 kN/m2. 0 NOMENCLATURE FOR TH2 The following nomenclature has been used for the theory and calculations presented in this manual: Name Piston diameter Cross-sectional area Mass of piston Mass on mass piston Applied mass Acceleration due to gravity Applied force Nom d A Mp Mm Ma g F Units m m? kg kg kg m/s2 kg Type Given Calculated Given Recorded Calculated Given Recorded Definition The diameter of the dead weight calibrator piston. Cross-sectional area of dead weight calibrator cylinder. Mass of the dead-weight calibrator piston. Mass applied to piston. Ma = Mp + Mm g = 9. 1 m/s2 Force applied to fluid in system by piston and masses. F = g x Ma Pressure applied to fluid by dead weight calibrator P = F/A Ambient (atmospheric) pressure of the surroundings. Applied pressure relative to the pressure of total vacuum Needle angle taken from Bourdon gauge scale Semiconductor output taken from console display Gauge pressure taken from Bourdon gauge scale Calibrated semiconductor output taken from console display Applied pressure Barometric pressure Absolute pressure Needle angle Semi-conductor output Indicated Bourdon gauge pressure Indicated semi-conductor pressure Pa Patm Pabs ? e Pb Ps N/m2 N/m2 N/m2 Calculated Recorded Calculated degree Recorded V N/m2 N/m2 Recorded Recorded Recorded 61 NOMENCLATURE FOR ERROR ANALYSIS The following nomenclature has been used for the error analysis presented in this manual: Name Indicated value Actual value Range Definition Gauge reading, i. e. the pressure indicated by sensor used True pressure, pressure applied by dead-weight calibrator Total range of values covered in the results, or total range of values measurable on instrument scale. Calculation Pi = Pb or Ps, depending on the sensor used Actual value = Applied pressure, Pa Range = Largest result – Smallest result = Pi max – Pi min or Range = Maximum possible reading – Minimum possible reading (200 kN/m? for apparatus used) No calculation. Precise data have a small scatter, indicating minimal random error ea = |Pi – Pa | ea max = ? (Pi – Pa)max? e%a = ea max X 100 Pa e%f = ea max X 100 Range Pmin = P1 + P2 + †¦.. + Pn n da = |Pi – Pmin| dm = da1 + da2 + †¦ + dan n ? = da12 + da32 + †¦ + dan2 n-1 ? Precision How closely the results agree with each other. Actual difference Modulus of the difference between indicated value and actual value Accuracy Maximum difference between indicated pressure and actual pressure Percentage accuracy Greatest difference between of actual scale reading indicated pressure and actual pressure, as a percentage of the actual pressure. Percentage accuracy Greatest difference between of full-scale reading indicated pressure and actual pressure, as a percentage of the range. Mean Sum of results divided by number of results. Absolute deviation Difference between a single result and the mean of several results Mean deviation Sum of the absolute deviations divided by the number of absolute deviations Standard deviation Commonly used value in analysis of statistical data 62 DATA SHEET 7 RELATIVE AND ABSOLUTE PRESSURE The measurement of any physical property relies upon comparison with some fixed reference point. Pressure is one such property, and pressure measurement must begin by defining a suitable fixed point. An obvious reference point is that of the ambient pressure of the surroundings. Pressure scales have been based around a zero point of the pressure of the atmosphere at sea level. Pressures lower than atmospheric are assigned negative values; pressures higher than atmospheric have positive values. Gauges for measuring pressure give readings relative to this zero point, by comparing the pressure of interest to the pressure of the surrounding air. Pressure measured with such a gauge is given relative to a fixed value, and is sometimes termed gauge pressure. Gauge measure pressure difference between the pressure to be measured and the barometric (ambient) pressure. This may then need adjusting, to take into account any difference between barometric pressure and the pressure at sea level. Many calculations using equations derived from fundamental physical laws require absolute pressure values. Absolute pressure is the pressure relative to a total absence of pressure (i. e. a total vacuum). On an absolute pressure scale, all pressures have a positive value. The following chart illustrates the difference between gauge pressure, barometric pressure, and absolute pressure. 63 DATA SHEET 8 TECHNICAL DATA The following information may be of use when using this apparatus: Operating range of dead-weight pressure calibrator Diameter of dead-weight calibrator piston Cross-sectional calibrator area of dead-weight 20 kN/m2 – 200 kN/m2 0. 017655 m 0. 000245 m2 20 kN/m2 150 mL Pressure produced in cylinder by mass of piston with no applied masses Approximate capacity of priming vessel 64 EXPERIMENT P1 CONCEPTS OF PRESSURE AND PRESSURE SENSOR BEHAVIOUR OBJECTIVE To gain a basic understanding of the concept of pressure and its measurement. To investigate the behavior of two kinds of pressure sensor, and the effect of damping on pressure measurement. †¢ To gain a basic understanding of the concept of pressure and its measurement. †¢ To investigate the behaviour of two kinds of pressure sensor †¢ To observe the effect of damping on pressure measurement METHOD To investigate the response of two kinds of pressure sensor to a pressure applied by a dead-weight calibrator device. To investigate the response of these sensors to the application of a sudden pressure spike, with varying levels of restriction of the liquid between the pressure application and the sensor. THEORY Pressure is the force exerted by a medium, such as a fluid, on an area. In the TH2 apparatus, pressure is exerted by a piston on a column of water. The pressure applied is then equal to the force exerted by the piston over the cross-sectional area of the fluid. The use of the piston and masses with the cylinder generates a measurable reference pressure, Pa: Pa = Fa A 65 where Fa = gMa, and Fa = force applied to the liquid, Ma = total mass (incl. piston), and A = area of piston. The area of the piston can be expressed in terms of its diameter, d, as: A = ? d2 4 The units of each variable must agree for the equations to be valid. Using SI units, Pa will be in Newtons per square metre (N/m? , also known as Pascals) if Fa is in Newtons, A is in square metres, and d is in metres. The use of specific units of pressure will be covered in exercise B. For this exercise the area of the cylinder is a constant. The pressure can therefore be considered directly proportional to the mass applied to the mass on the piston Pressure measurement is normally concerned with measuring the effects of a pressure differential between two points in a fluid. The simplest form of pressure sensor is a manometer tube, in which a tube of fluid is exposed at one end to the first point in the fluid, and at the other to the second point. Any pressure differential causes a displacement of fluid within the tube, which is proportional to the difference. Manometers (not included with the TH2 apparatus) are cheap, simple, and can be designed to cover a wide range of pressures. However, they are best used for measuring static pressures below about 600 kN/m? , as the required height of the fluid becomes unworkable at greater pressures. Their dynamic response is poor, so they are best suited to measuring static or slowly changing pressures. Some fluids used are toxic (such as mercury), and may be susceptible to temperature change. The Bourdon-type pressure gauge consists of a curved tube of oval cross-section. One end is closed, and is left free to move. The other end is left open to allow fluid to enter, and is fixed. The outside of the tube remains at ambient pressure. When fluid pressure inside the tube exceeds the pressure outside the tube, the section of the tube tends to 66 ecome circular, causing the tube to straighten (internal pressure lower than the ambient pressure conversely causes increased flattening, and the curve of the tube increases). A simple mechanical linkage transmits the movement of the free end of the tube to a pointer moving around dial. This type of gauge is one of the two kinds included in the TH2 apparatus. The second type of pressure gauge included as part of the TH2 is an electromechani cal device. In a basic semiconductor pressure sensor, silicon strain gauges are fixed to one side of a diaphragm. The two sides of the diaphragm are exposed to the two different pressures. Any pressure differential causes the diaphragm to expand towards the lower-pressure side, producing a change in the strain gauge voltage reading. The electronic semiconductor pressure sensor included with the TH2 is a more refined device with improved reliability and sensitivity for pressure measurement. It includes temperature compensation to reduce the effects of temperature variation on the results. The strain gauges used are formed by laying down a protective film of glass onto stainless steel, followed by a thin film of silicon. The silicon is doped to produce semiconductor properties, and a mask is photoprinted onto it. The unmasked silicon is then removed, leaving a pattern of silicon semiconductor strain gauges molecularly bonded onto the surface of the steel. The gauges are connected to an Ohmmeter through a Wheatstone bridge, to amplify the signal produced. 67 In this type of sensor, a diaphragm is still used, but instead of fixing the strain gauges to the surface, the deflection of the diaphragm moves a steel force rod. This transfers the force to one end of the steel strip that the semiconductor resistors are bonded to. The resulting deflection of the strip causes compression in some strain gauges, and tension in others, changing their resistance and producing a measurable output. Both the TH2 pressure sensors are set up to indicate the pressure differential between atmospheric pressure, and fluid pressurized with the use of the dead-weight calibrator. The fluid passes through a damping valve, positioned between the calibrator and the sensors. By partially closing the valve, fluid flow can be restricted. This affects the speed at which pressure is transferred from the point of application to the sensors. EQUIPMENT SET UP Level the apparatus using the adjustable feet. A circular spirit level has been provided for this purpose, mounted on the base of the dead-weight calibrator. Check that the drain valve (at the back of the Bourdon gauge base) is closed. Fill the priming vessel with water (purified or de-ionized water is preferable). Fully open the damping valve and the priming valve With no masses on the piston, slowly draw the piston upwards a distance of approximately 6cm (i. e. a full stroke of the piston). This draws water from the priming vessel into the system. Firmly drive the piston downwards, to expel air from the cylinder back towards the priming vessel. Repeat these two steps until no more bubbles are visible in the system. It may be helpful to raise the central section of the return tube between the manifold block and 68 the priming vessel. This will help to prevent air being drawn back into the system as the piston is raised. Raise the piston close to the top of the cylinder, taking care not to lift it high enough to allow air to enter, and then close the priming valve. PROCEDURE This equipment has been designed to operate over a range of pressure from 0 kN/m2 to 200 kN/m2. Exceeding a pressure of 200 kN/m2 may damage the pressure sensors. In order to avoid such damage, DO NOT APPLY CONTINUOUS PRESSURE TO THE TOP OF THE PISTON ROD WHEN THE PRIMING VALVE IS CLOSED except by application of the mass supplied. An impulse may be applied to the piston when operating at a fluid pressure of less than 200 kN/m2, as is described later in this procedure. Behavior of pressure sensors Spin the piston in the cylinder, to minimize friction effects between the piston and the cylinder wall. While the piston is spinning, record the angle through which the Bourdon gauge needle has moved, and the voltage output of the electronic sensor. Apply a ? kg mass to the piston. Spin the piston and take a second set of readings for the Bourdon gauge needle angle and the electronic sensor. Repeat the procedure in ? kg increments. When using several masses, it will be necessary to place the 2 ? kg mass on top of the other masses. Repeat the procedure while removing the masses again, in ? kg increments. This gives two results for each applied mass, which may be averaged in order to reduce the effects of any error in an individual reading. Effect of damping Apply a single mass to the piston, and spin it. While the piston is spinning, apply an impulse to the top of the piston by striking the top of the rod once, with the flat of the hand. Watch the behavior of the Bourdon gauge needle. Note the final sensor reading after the response settles. Slightly close the damping valve. Change the mass, spin the piston again, and apply an impulse to the rod. Observe any changes in the sensor responses. Repeat the procedure, closing the damping valve a little at a time and noting the response and the final sensor reading each time. RESULTS Tabulate your results under the following headings:- 69 Mass applied to calibrator Mm (kg) Deflection of Bourdon gauge needle (degrees) Output from electrochemical pressure sensor (mV) Notes on sensor behavior (damping) Plot a graph of sensor response against applied mass for each sensor. 70 EXPERIMENT P2 CONCEPTS OF PRESSURE MEASUREMENT AND CALIBRATION OBJECTIVE To convert an arbitrary scale of pressure sensor output into engineering units. To calibrate a semiconductor pressure sensor. METHOD To make use of a dead-weight calibrator in order to produce known forces in a fluid. THEORY It is recommended that students read Data Sheet 1: Relative and Absolute Pressures before proceeding with this exercise. Pressure sensor calibration Variation in a pressure sensor reading may be calibrated, using known pressures, to give a gauge reading in engineering units. From exercise A, the dead-weight calibrator used in the TH2 produces a known reference pressure by applying a mass to a column of fluid. The pressure produced is Pa = F Aa where Fa = gMa, and Fa is the force applied to the liquid in the calibrator cylinder. Ma is the total mass (including that of the piston) 71 g is the acceleration due to gravity, and A is the area of piston. The area of the piston can be expressed in terms of its diameter, d, as: A = ? d2 4 The pressure in the fluid may then be calculated in the relevant engineering units. These known pressures may then be compared to the pressure sensor outputs over a range of pressures. The relationship between sensor output and pressure may be turned into a direct scale, as on the Bourdon gauge scale. Alternatively, a reference graph may be produced. Where the relationship is linear and the sensor output is electrical, the sensor may be calibrated using simple amplifier (a conditioning circuit). When using SI units, the units of pressure are Newtons per square meter (N/m? , also known as Pascals). To calculate the pressure in N/m? , M must be in kg, d in m, and g in m / s?. For the pressure range covered in this exercise, it will be more convenient to use units of kN/m? , where 1 kN/m? = 1000 N/m? (1 N/m? = 0. 001 kN/m? ). Barometric pressure: pressure units and scale conversion Barometric pressures is usually measured in bar. One bar is equal to a force of 105 N applied over an area of 1m?. While bar and N/m? have the same scale interval, pressure in bar often has a more convenient value when measuring barometric pressure. Pressure may also be measured in millimetres of mercury (mmHg). The pressure is given in terms of the height of a column of mercury that would be required to exert an equivalent pressure to that being measured. Another possible unit of measurement is atmospheres (atm). One standard atmosphere was originally defined as being equal to the pressure at sea level at a temperature of 15 °C. A pressure unit still in everyday use is pounds per square inch (psi or lbf / in.? ). One psi is equal to a weight of one pound applied over an area of 1 in.? If a barometer is available to measure the ambient pressure in the room where the equipment is located, the barometer reading should be converted SI units. Pressures may be converted from one scale to another using a conversion factor. A list of conversion factors is provided below. 72 1 atm = = = = = = = = = = = = = = = = = = = = 101. 3 x 103 101. 3 1. 013 760 14. 696 100 x 103 100 0. 987 750. 006 14. 504 133. 3 x 103 133. 3 1. 33 1. 316 19. 337 6. 895 x 106 6. 895 x 103 68. 948 68. 046 51. 715 N/m2 kN/m2 bar mmHg psi N/m2 kN/m2 atm mmHg psi N/m2 kN/m2 bar atm psi N/m2 kN/m2 bar atm mmHg 1 bar 1 mmHg x 103 1 psi x 103 ADDITIONAL EQUIPMENT REQUIRED Values for the piston diameter and weight are provided. These may be replaced by your own measurements if desired. The following equipment will be required to do so: a) Vernier calli pers or a ruler, to measure the piston diameter b) A weigh-balance or similar, to measure the piston weight EQUIPMENT SET UP Carefully remove the piston from the cylinder, weigh it. Take care not to damage the piston, as it is part of a high precision instrument and any damage will affect the accuracy of the experimental results. Level the apparatus using the adjustable feet. A circular spirit level has been mounted on the base of the dead weight calibrator for this purpose. Check that the drain valve (at the back of the Bourdon gauge base) is closed. Fill the priming vessel with water (purified or de-ionized water is preferable). Open the damping valve and the priming valve. 73 With no masses on the piston, slowly draw the piston upwards a distance of approximately 6cm (i. e. full stroke of the piston). This draws water from the priming vessel into the system. Firmly drive the piston downwards, to expel air from the cylinder back towards the priming vessel. Repeat these two steps until no more bubbles are visible in the system. It may be helpful to raise the central section of the return tube between the manifold block and the priming vessel. This will help to prevent air being drawn back into the system as the piston is raised. Raise the piston close to the top of the cylinder, taking care not to lift it high enough to allow air to enter, and then close the priming valve. Set the selector switch on the console to ‘Output’. PROCEDURE This equipment has been designed to operate over a range of pressure from 0 kN/m2 to 200 kN/m2. Exceeding a pressure of 200 kN/m2 may damage the pressure sensors. In order to avoid such damage, DO NOT APPLY CONTINUOUS PRESSURE TO THE TOP OF THE PISTON ROD WHEN THE PRIMING VALVE IS CLOSED except by application of the mass supplied. Conversion of an arbitrary scale into engineering units Spin the piston to reduce the effects of friction in the cylinder. With the needle still spinning, record the angle indicated by the Bourdon gauge needle. Place a ? kg mass on the piston, and spin the piston. Record the value of the applied mass, and the angle indicated by the Bourdon gauge needle. Increase the applied mass in increment of ? kg. Spin the piston and record the needle angle each increment. Repeat the measurements while decreasing the applied mass in steps of ? kg. This gives two readings for each applied mass, which may be averaged to reduce the effect of any error in an individual reading. Calculate the applied pressure at each mass increment. Calculate the average needle angle at each pressure increment. Repeat the experiment, this time recording the applied mass and the indicated pressure on the Bourdon gauge scale. Compare this to the average needle angle recorded previously. 74 Calibration of a semiconductor pressure sensor NOTE: This procedure differs if the TH2-303 software is being used. Please refer to the online product Help Text if using this software. Spin the piston. Record the voltage indicated on the semiconductor output display on the console. Place a ? kg mass on the piston, and spin the piston. Record the applied mass, and the voltage indicated on the semiconductor output display on the console. Increase the applied mass in steps of ? kg, spinning the piston and recording the semiconductor output each time. Repeat the measurement while decreasing the applied mass in steps of ? kg. Calculate the applied pressure at each mass increment. Calculate the average sensor output at each pressure increment. Slowly open the priming valve. Open the valve to its maximum, and check that the damping valve is also fully open. The fluid in the system will now be at approximately atmospheric pressure (it will be slightly higher than atmospheric due to the height of fluid in the reservoir, but this is negligible compared to the range of the sensors). Switch the selector knob on the console to PRESSURE Turn the ZERO control on the console until the display read zero, to set the first reference point for the sensor calibration. Raise the piston close to the top of the cylinder, taking care not to lift it high enough to allow air to enter, and then close the priming valve. Place a large mass on the piston, and calculate the corresponding applied pressure. Spin the piston and adjust the SPAN control until the sensor output matches the applied pressure, to set the second reference point for the calibration. Remove the masses from the piston. Take a set of readings from the calibrated semiconductor sensor, by adding masses to the piston in ? kg increments. Repeat the reading while decreasing the applied mass. This gives two reading for each applied mass, which may be averaged in order to reduce the effect of any error in an individual reading. 75 RESULTS Tabulate your results under the following headings: Barometric pressure Mass of piston Mp Diameter of cylinder, d Cross-sectional area of cylinder, A Mass on piston Mm (kg) Applied mass Ma (kg) Applied force Fa (N) Applied pressure †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. Needle angle N/m2 kg m m2 Indicated Indicated SemiBourdon conductor semiconductor pressure pressure output Pb Ps Pa E ? (mV) (N/m2) (degrees) (N/m2) (N/m2) Plot graphs of average needle angle against applied pressure for the Bourdon gauge, and voltage output against applied pressure for the semiconductor sensor. Plot a graph of indicated pressure against actual pressure for the Bourdon gauge and the calibrated semiconductor pressure sensor. If there is facility for measuring barometric pressure, it is possible to calculate the absolute pressure corresponding to each applied pressure increment. The ambient pressure of the surroundings, Patm should be measured, then converted into N/m2 (if required). An additional column should be added to the results table: Absolute Pressure, Pabs (N/m2). Absolute pressure may then be calculated as Pabs = Pa + Patm 76 EXPERIMENT P3 ERRORS IN PRESSURE MEASUREMENT OBJECTIVE To investigate the sources of error when measuring pressure. METHOD Errors in measuring a quantity, such as pressure, can come from a number of sources. Some can be eliminated by careful choice of equipment and experimental method. Other errors are unavoidable, but can be minimized. In any experiment, it is good practice to note any possible sources of error in the results, and to give an indication of the magnitude of such errors. Errors fall into three general categories: Avoidable errors These are errors that must be eliminated, as any results including such errors will often be meaningless. Such errors include: †¢ †¢ †¢ †¢ Incorrect use of equipment Incorrect recording of results Errors in calculations Chaotic errors, i. e. random disturbances, such as extreme vibration or electrical noise that are sufficient to mask the experimental results. 7 Random errors Random errors should be eliminated if possible, by changing the design of the experiment or waiting until conditions are more favorable. Even if they cannot be eliminated, many random errors may be minimized by making multiple sets of readings, and averaging the results. Random errors include: †¢ †¢ †¢ †¢ Variation of experimental conditions (e. g. changes in ambie nt temperature) Variation in instrumentation performance Variation due to material properties and design (e. g. effect of friction) Errors of judgement (e. g. nconstancy in estimating a sensor reading) Systematic errors Systematic errors produce a constant bias or skew in the results, and should be minimized where possible. They include: †¢ †¢ †¢ †¢ Built-in errors (e. g. zero error, incorrect scale graduation) Experimental errors (due to poor design of the experiment or the apparatus) Systematic human errors (e. g. reading from the wrong side of a liquid meniscus) Loading error (errors introduced as a result of the act of measurement- for example, the temperature of a probe altering the temperature of the body being measured) Errors may also be described in a number of ways: Actual difference – the difference between the indicated value (the value indicated by the gauge or sensor) and the actual scale reading (the true value of the property being measured). The actual value must be known to calculate the actual difference. Accuracy – the maximum amount by which the results vary from the actual value. The actual value must be known. Percentage accuracy of the actual scale reading – the greatest difference between the actual value and the indicated value, expressed as a percentage of the actual value. The actual value must be known. Percentage accuracy of the full-scale reading (total range of the measurement device) – the greatest difference between the actual value and the indicated value, expressed as a percentage of the maximum value of the range being used. The actual value must be known. Mean deviation (or probable error) – The absolute deviation of a single result is the difference between a single result, and the average (mean) of several results. The mean deviation is the sum of the absolute deviations divided by their number. The actual value is not required. The mean deviation is an indication of how closely the results agree with each other. 78 Standard deviation (or mean square error) – the standard deviation is the square root of the mean of the squares of the deviations (‘better’ results are obtained by dividing the sum of the values by the one less than the number of values). This is a common measure of the preciseness of a sample of data- how closely the results agree with each other. The actual value is not required. ADDITIONAL EQUIUPMENT REQUIRED Values for the piston diameter and weight are provided. These may be replaced by your own measurements if desired. The following equipment will be required to do so: †¢ †¢ Vernier callipers or a ruler, to measure the piston diameter A weigh-balance or similar, to measure the piston weight EQUIPMENT SET UP To prime the cylinder, the following procedure should be followed (where this is required in the experiment): Level the apparatus using the adjustable feet. A circular spirit level has been mounted on the base of the dead weight calibrator for this purpose. Check that the drain valve (at the back of the Bourdon gauge base) is closed. Fill the priming vessel with water (purified or de-ionized water is preferable). Fully open the damping valve and the priming valve. With no masses on the piston, slowly draw the piston upwards a distance of approximately 6cm (i. e. a full stroke of the piston). This draws water from the priming vessel into the system. Firmly drive the piston downwards, to expel air from the cylinder back towards the priming vessel. Repeat these two steps until no more bubbles are visible in the system. It may be helpful to raise the central section of the return tube between the manifold block and the priming vessel. This will help to prevent air being drawn back into the system as the piston is raised. Raise the piston close to the top of the cylinder, taking care not to lift it high enough to allow air to enter, then close the priming valve. PROCEDURE This equipment has been designed to operate over a range of pressure from 0 kN/m2 to 200 kN/m2. Exceeding a pressure of 200 kN/m2 may damage the pressure sensors. In order to avoid such damage, DO NOT APPLY CONTINUOUS PRESSURE TO THE 79 TOP OF THE PISTON ROD WHEN THE PRIMING VALVE IS CLOSED except by application of the mass supplied. The following experiments give suggested ways in which particular sources of error may be investigated. It is recommended that only one or two be attempted in a single laboratory session, with each being repeated several times, giving multiple samples for the error analysis. Basic Error Analysis: The accuracy of the semiconductor calibration may be investigated by performing standard error calculations on the calibrated sensor output, using the results obtained in Experiment P2. If results are not available for analysis, the following procedure should be followed: Slowly open the priming valve. Open the valve to its maximum, and check that the damping valve is also fully open. The fluid in the system will now be at approximately atmospheric pressure (it will be slightly higher than atmospheric due to the height of fluid in the reservoir, but this is negligible compared to the range of the sensors). Switch the selector knob on the console to PRESSURE. Turn the ZERO control on the console until the display read zero, to set the first reference point for the sensor calibration. Raise the piston close to the top of the cylinder, taking care not to lift it high enough to allow air to enter, then close the priming valve. Place a large mass on the piston, and calculate the corresponding applied pressure. Spin the piston, and adjust the SPAN control until the sensor output matches the applied pressure, to set the second reference point for the calibration. Remove the masses from the piston. Take a set of readings from the calibrated semiconductor sensor, adding masses to the pan in ? kg increments, and again while decreasing the applied mass. This provides two set of readings for data analysis. The experiment should be repeated to provide further sets of data. Avoidable errors: Incorrect use of equipment Level the apparatus using the adjustable feet. A circular spirit level has been mounted on the base of the dead-weight calibrator for this purpose Check that the drain valve (at the back of the Bourdon gauge base) is closed, and the damping valve is fully open. 80 Remove the piston from the cylinder, then fill the priming vessel with water (purified or de-ionized water is preferable). Close the priming valve, then replace the piston in the cylinder. Take a set of readings without priming the system first. Random errors: Friction effects Prime the system as described in the equipment set up instructions. Tilt the board at an angle of about 5 to 10 degrees. THE EQUIPMENT BASE MUST STILL BE FIRM AND SECURE. Titling the apparatus in this way will exaggerate any friction effects, as the force applied by the piston will no longer be acting straight downwards on the column of fluids, but will have components acting at right-angles to cylinder wall. Spin the piston. Take one reading while the piston is spinning, then observe the behavior of the needle. Continue to watch the needle as the piston stops spinning, then make a note of the new gauge reading. Apply masses to the piston in ? kg increments. At each step, spin the piston, note the sensor output, and then take a second reading after the piston stops spinning. Systematic errors: Zero error Calibrate the semiconductor pressure sensor, but do not include mass of piston in the applied mass when calculating the applied pressure. Take a set of readings from the calibrated semiconductor sensor over a range of applied masses, now including the piston mass in the applied mass calculation. Human error Take a set or readings from the Bourdon gauge pressure scale, but stand at an angle to the dial face when taking each reading. Keep the same viewing angle for each reading. This illustrates the effect of parallax on the readings taken. RESULTS Tabulate your results under the headings on the following page: For each result, calculate the absolute difference, ea between indicated value Pi and the applied pressure Pa. 81 Find the maximum absolute difference, the accuracy ea max and use this value and the corresponding indicated pressure to calculate the % accuracy of actual scale reading and the % accuracy of full-scale reading (use a range of 200 kN/m2). Correlate the data for several test runs, to give a set of indicated pressure readings corresponding to a single applied pressure. Use this correlated data table to calculate the mean of the results, Pmean, the mean deviation, dm, the absolute deviation, da, and the standard deviation, ?. Errors can also be illustrated graphically: 85 Piston diameter, d = †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. m Piston mass, MP = †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. kg Experimental conditions : †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦ Mass Applied Applied Applied Indicated Mean Absolute Standard Actual Accuracy % % Mean on deviation deviation deviation Accuracy Accuracy of mass force pressure pressure difference piston Actual Full result scale scale reading reading Mm dm da PI ea Emax e%a e%f Pmin Ma Fa Pa ? kg) (kg) (kN) (kN/m2) (kN/m2) (kN/m2) (kN/m2) (kN/m2) (kN/m2) 86 Plot a graph of actual pressure against indicated pressure. On the same graph, plot a straight line showing the actual pressure. This will illustrate three characteristics of the results: †¢ †¢ Deviati on of sensor readings from the actual value. Whether any deviation from the true reading is systematic (the graph will be a straight line or a smooth curve) or random (the graph will have no obvious relationship). Precision of the results. Precise results will be close together, not widely scattered. Precise results may still deviate strongly from the actual value. †¢

Gay marriage

Creating discrimination against same-sex couples. People of faith are the biggest advocates against same-sex marriages. With the belief that marriage is the foundation for procreation, same-sex couples, without the ability to have their own child, should not be allowed the right of marriage. Seeing that there are many rights and responsibilities associated with marriage, same-sex couples are denied these and are being discriminated against.Same-sex couples are denied the right to make decisions regarding their partner's health and medical treatment. This emotional trauma, as well as the inability to adopt one another's children, is experienced by same-sex couples every day. Although many states have adopted civil unions, they are separate and unequal. Same-sex marriage should be legalized to create equality and eliminate the injustice involving same-sex couples. The legalization of same-sex arriage has been a battle that has been raging since the late twentieth century.By not allowin g same-sex marriage, the United Sates is creating discrimination against same-sex couples. People of faith are the biggest advocates against same-sex marriages. With the belief that marriage is the foundation for procreation, same-sex couples, without the ability to have their own child, should not be allowed the right of marriage. Seeing that there are many rights and responsibilities associated with arriage, same-sex couples are denied these and are being discriminated against.Same-sex couples are denied the right to make decisions regarding their partner's health and medical treatment. This emotional trauma, as well as the inability to adopt one another's children, is experienced by same-sex couples every day. Although many states have adopted civil unions, they are separate and unequal. Same-sex marriage should be legalized to create equality and eliminate the injustice involving same-sex couples. Gay Marriage Gay Marriage BY gapping Gay Marriage: The Struggle for Equal Rights Gerald Priest Gene. 195 July 2, 2014 Lily David Since the age of dawn people have fought for equal rights, Blacks, Mexicans and women Just to name a few. In this day of age by now everyone should have equal rights but they do not. The gay and lesbian community is still struggling for equal rights. Gays and lesbian want rights Just like everyone else like marriage. Gay marriage is important to the gay and lesbian community to make them feel equal, have the benefits like others and be socially accepted. Equal Rights In February 2014, Arizona government introduced SHABBY.SHABBY is a bill that would allow business owners in Arizona to legally deny service to same sex couples by citing their religious beliefs. Governor Jan Brewer vetoed SHABBY, Brewer citied â€Å"unintended and negative consequences† (Broody, 2014 peg. 56). Equal rights is a given right, well not exactly. If someone falls into a certain group or c ommunity, like the gay and lesbian community, their rights are very limited. Marriage is one of those rights that the gay and lesbian community does not have. Marriage is a human right which should be allowed for everyone and not discriminate others. BenefitsBenefits plays a major role in gay marriage, not only for finances but medical wise. For example there is a gay couple, not married because the state does not allow it, and one of them becomes very ill and passes away. Well the other partner does not have any rights to claim his partner's body, his partner's family does. The partner can not even plan the funeral or even keep anything that was his partner's. Sometimes this is the case because their family never liked their child being with the same sex, so they punish their child's partner by doing so. So having that title as being married is very important.Most Jobs you have to be married to receive your partner's benefits but how if the state will not allow them to marry. In an article it states, â€Å"The Defense of Marriage Act by the Congress of the U. S. Prevents the same-sex partners from receiving benefits† (Passe, 2012 peg. 459-472). This is Congress denying benefits, their rights to gays and lesbians. Social Acceptance When society see two guys holding hands or even kissing, they call them names, throw things at them, give them dirty looks or even worst cases kill them. Now it is kind of different when people see two girls hold hands or even kiss.Society views says and lesbians as a disgrace, they look down on them like they are not even humans. Gays and lesbians Just want to walk and hold hands without the fear of society showing negative behavior. â€Å"Although sharply divided, public attitudes toward gays and lesbians are rapidly changing to reflect greater acceptance, with younger generations leading the way (Harms, 2011). † Gays and lesbians have seen a change in society, society is a bit more accepting than how it used to be s lowly but surely. Conclusion The gay and lesbian community has overcame struggles to get to where they are at today, but still going through more struggles.The importance of gay marriage is equal rights, benefits and being socially accepted. Gay marriage Creating discrimination against same-sex couples. People of faith are the biggest advocates against same-sex marriages. With the belief that marriage is the foundation for procreation, same-sex couples, without the ability to have their own child, should not be allowed the right of marriage. Seeing that there are many rights and responsibilities associated with marriage, same-sex couples are denied these and are being discriminated against.Same-sex couples are denied the right to make decisions regarding their partner's health and medical treatment. This emotional trauma, as well as the inability to adopt one another's children, is experienced by same-sex couples every day. Although many states have adopted civil unions, they are separate and unequal. Same-sex marriage should be legalized to create equality and eliminate the injustice involving same-sex couples. The legalization of same-sex arriage has been a battle that has been raging since the late twentieth century.By not allowin g same-sex marriage, the United Sates is creating discrimination against same-sex couples. People of faith are the biggest advocates against same-sex marriages. With the belief that marriage is the foundation for procreation, same-sex couples, without the ability to have their own child, should not be allowed the right of marriage. Seeing that there are many rights and responsibilities associated with arriage, same-sex couples are denied these and are being discriminated against.Same-sex couples are denied the right to make decisions regarding their partner's health and medical treatment. This emotional trauma, as well as the inability to adopt one another's children, is experienced by same-sex couples every day. Although many states have adopted civil unions, they are separate and unequal. Same-sex marriage should be legalized to create equality and eliminate the injustice involving same-sex couples. Gay Marriage Gay Marriage BY gapping Gay Marriage: The Struggle for Equal Rights Gerald Priest Gene. 195 July 2, 2014 Lily David Since the age of dawn people have fought for equal rights, Blacks, Mexicans and women Just to name a few. In this day of age by now everyone should have equal rights but they do not. The gay and lesbian community is still struggling for equal rights. Gays and lesbian want rights Just like everyone else like marriage. Gay marriage is important to the gay and lesbian community to make them feel equal, have the benefits like others and be socially accepted. Equal Rights In February 2014, Arizona government introduced SHABBY.SHABBY is a bill that would allow business owners in Arizona to legally deny service to same sex couples by citing their religious beliefs. Governor Jan Brewer vetoed SHABBY, Brewer citied â€Å"unintended and negative consequences† (Broody, 2014 peg. 56). Equal rights is a given right, well not exactly. If someone falls into a certain group or c ommunity, like the gay and lesbian community, their rights are very limited. Marriage is one of those rights that the gay and lesbian community does not have. Marriage is a human right which should be allowed for everyone and not discriminate others. BenefitsBenefits plays a major role in gay marriage, not only for finances but medical wise. For example there is a gay couple, not married because the state does not allow it, and one of them becomes very ill and passes away. Well the other partner does not have any rights to claim his partner's body, his partner's family does. The partner can not even plan the funeral or even keep anything that was his partner's. Sometimes this is the case because their family never liked their child being with the same sex, so they punish their child's partner by doing so. So having that title as being married is very important.Most Jobs you have to be married to receive your partner's benefits but how if the state will not allow them to marry. In an article it states, â€Å"The Defense of Marriage Act by the Congress of the U. S. Prevents the same-sex partners from receiving benefits† (Passe, 2012 peg. 459-472). This is Congress denying benefits, their rights to gays and lesbians. Social Acceptance When society see two guys holding hands or even kissing, they call them names, throw things at them, give them dirty looks or even worst cases kill them. Now it is kind of different when people see two girls hold hands or even kiss.Society views says and lesbians as a disgrace, they look down on them like they are not even humans. Gays and lesbians Just want to walk and hold hands without the fear of society showing negative behavior. â€Å"Although sharply divided, public attitudes toward gays and lesbians are rapidly changing to reflect greater acceptance, with younger generations leading the way (Harms, 2011). † Gays and lesbians have seen a change in society, society is a bit more accepting than how it used to be s lowly but surely. Conclusion The gay and lesbian community has overcame struggles to get to where they are at today, but still going through more struggles.The importance of gay marriage is equal rights, benefits and being socially accepted. Gay Marriage Gay Marriage BY gapping Gay Marriage: The Struggle for Equal Rights Gerald Priest Gene. 195 July 2, 2014 Lily David Since the age of dawn people have fought for equal rights, Blacks, Mexicans and women Just to name a few. In this day of age by now everyone should have equal rights but they do not. The gay and lesbian community is still struggling for equal rights. Gays and lesbian want rights Just like everyone else like marriage. Gay marriage is important to the gay and lesbian community to make them feel equal, have the benefits like others and be socially accepted. Equal Rights In February 2014, Arizona government introduced SHABBY.SHABBY is a bill that would allow business owners in Arizona to legally deny service to same sex couples by citing their religious beliefs. Governor Jan Brewer vetoed SHABBY, Brewer citied â€Å"unintended and negative consequences† (Broody, 2014 peg. 56). Equal rights is a given right, well not exactly. If someone falls into a certain group or c ommunity, like the gay and lesbian community, their rights are very limited. Marriage is one of those rights that the gay and lesbian community does not have. Marriage is a human right which should be allowed for everyone and not discriminate others. BenefitsBenefits plays a major role in gay marriage, not only for finances but medical wise. For example there is a gay couple, not married because the state does not allow it, and one of them becomes very ill and passes away. Well the other partner does not have any rights to claim his partner's body, his partner's family does. The partner can not even plan the funeral or even keep anything that was his partner's. Sometimes this is the case because their family never liked their child being with the same sex, so they punish their child's partner by doing so. So having that title as being married is very important.Most Jobs you have to be married to receive your partner's benefits but how if the state will not allow them to marry. In an article it states, â€Å"The Defense of Marriage Act by the Congress of the U. S. Prevents the same-sex partners from receiving benefits† (Passe, 2012 peg. 459-472). This is Congress denying benefits, their rights to gays and lesbians. Social Acceptance When society see two guys holding hands or even kissing, they call them names, throw things at them, give them dirty looks or even worst cases kill them. Now it is kind of different when people see two girls hold hands or even kiss.Society views says and lesbians as a disgrace, they look down on them like they are not even humans. Gays and lesbians Just want to walk and hold hands without the fear of society showing negative behavior. â€Å"Although sharply divided, public attitudes toward gays and lesbians are rapidly changing to reflect greater acceptance, with younger generations leading the way (Harms, 2011). † Gays and lesbians have seen a change in society, society is a bit more accepting than how it used to be s lowly but surely. Conclusion The gay and lesbian community has overcame struggles to get to where they are at today, but still going through more struggles.The importance of gay marriage is equal rights, benefits and being socially accepted.