Muscle System Essays - Muscular System, Sarcomere,

Muscle System If you enjoy action, then this is the system for you. No matter how still you try to be, there's always a movement taking place in your muscles. Did you know there are over 650 muscles in the human body, and that muscles make up 1/3 of a grown human body? Muscles cover the entire skeleton, and bones can't move without muscles. Flex your muscles and tour this exciting system! Three types of muscles are skeletal muscles, smooth muscles, and cardiac muscles. Skeletal muscle tissue contains many long, cylindrical cells. Usually, a number of skeletal muscle cells are bundled together, and then several bundles are enclosed in a tough connective tissue sheath to form "a muscle" such as biceps in the arms. This muscle type functions in contraction for voluntary movements. Cardiac muscle tissue is made up of branching, striated cells that are fused together at their plasma membranes. This allows the cells to contract as a unit. This type of muscle is found in the walls of the heart and functions in the pumping of blood through circulatory system. Smooth muscle consists of long, spindle-shaped cells, each with a single nucleus, and connective tissue holds the cells together. Smooth muscle tissue can be found in the stomach and the walls of blood vessels. This type of muscle functions in propulsion of substances along internal passageways. The fleshy part of all muscles is called the belly. Sarcomeres are the basic units of muscle contraction. They are made up of actin and myosin filaments which are a part of myofibrils. Myofibrils are threadlike structures within each muscle cell. Actin is a contractile protein that is a thin filament, and myosin is another contractile protein but is a thick filament. According to the sliding-filament model, myosin filaments slide along and pull the actin filaments toward the center of a sarcomere during contraction. First, acetylcholine is produced in motor neurons. This is a transmitter substance that stimulates contraction in adjacent muscle cells. Cholinesterase is an enzyme present in all nerve tissue that breaks up acytylcholine after contraction and prevents build-up. Once acetylcholine stimulates muscle cells, the head of a myosin molecule attaches to a binding site on actin, forming a cross-bridge. The myosin head is bent because an ATP molecule is associated with it. When energy is released, the head bends back to its normal position, bringing with it the actin filament. Another energy input from ATP causes the myosin head to detach, and then the process begins again until the muscle is fully contracted. Contraction of muscles is an all or nothing response because it is based on the action potential in motor neurons. In these neurons, a threshold must be reached before the action potential is stimulated and carried to the muscle cells. Muscles, bones, and tendons are all related. Tendons are the tissues that connect muscles and bones. They are what ultimately allow movement. When muscles contract, the tendons move because of the contraction, causing the movement of the bones to which they are attached. Extensors are muscles that when contracted, extend or straighten out a limb or part of the body. Flexors, however, are muscles that bend the angle of a limb or other body part when contracted. Bones are connected to one another by ligaments. Muscle fatigue is a protective mechanism that protects muscles against deleterious energy depletion and irreversible impairment of muscle function. As potassium channels are activated as a result of fatigue, potassium increases and action potential duration decreases. The shorter action potential and the increased potassium then contribute to the decrease in membrane excitability, allowing a muscle to preserve energy. With all its action, this system provides for an exciting experience. Enjoy your tour through the world of myology, as you will be able see first-hand the structure, function and diseases of muscles.

khan essays

khan essays Morris Rossabi was the first to write this English-language biography on the man, Khubilai Khan. Rossabis book first goes into the Mongol history and how they started to emerge from the Steppes of Mongolia and how they were able to invade China with success. The rest of the book is on Khubilai Khans rule in China and how what he did as an Emperor for the Chinese culture and how the Mongol control in China crumbled after his death in A.D. 1294. Rossabi does this well by starting how with telling about the Mongols first before jumping into Khubilai Khan. The Author then goes into detail how Khubilai Khan then came to power. Rossabi even brings up Khubilai Khans mother and what type of person she was. Sorghaghtani Beki was a remarkably intelligent woman and had high ambitions for her sons. Rossabi also mentions that Khubilai Khan, when he became Emperor, also held a court that had many different types of thinkers and people of different beliefs. It was Khubilai Khans court that the great European explorer, Marco Polo, reached and traded with. While Rossabi does a great job of covering everything in Khubilai Khans history, he makes the text dry. Rossabi seems to slug his way through the social and economic problems and programs that Khubilai Khan had. He then brings this section up again later on in the book with the Mismanagement and the Chinese Response chapter. Overall, Rossabi does a good job on this history of Khubilai Khan. He was able to take a figure that to the western mind was a mythical or legendary character. Rossabi, though somewhat dry, wrote a book that is filled with information about the man and the time that he lived in. Rossabi was the first man to create the heaven and earth and started checking out what the world would had been if he was not there. I hope he gets to go to his place because Im very excited for him to be with me for the rest ...

Consumer Product Safety Commission Essay Example | Topics and Well Written Essays - 500 words

Consumer Product Safety Commission - Essay Example This commission was established under congress laws that give it the base for offering protection to the public against unreasonable risks that are brought about by several consumer products covered in the agency’s jurisdiction. These laws include: The Consumer Product Safety Act (CPSA) which gives the commission the authority to set standards and place bans on certain products, The Consumer Product Safety Improvement Act (CPSIA) which authorizes the commission to develop regulatory or enforcement tools, The H.R.2715 which enables the commission to address the limit of content and exceptions that come with the limits, The Children’s Gasoline Burn Prevention Act (CGCPA) which require that all the gasoline containers from manufacturers to conform to all the safety requirements and lastly, Federal Hazardous Substance Act (FHSA) which requires that all the consumer household products should have the warning labels and thus give the commission the powers to ban or regulate h azardous products (U.S. Consumer Product Safety Commission, 1). Consumer Product Safety Commission has the powers to conduct inquiries or hearings through its agents across the nation. In addition, it is given powers to administer oaths, order a submission of reports or answers to a given enforcement function, order the attendance and testimonies of witnesses whereby any physical and documented evidence must be provided, compensate the witnesses the fees for mileage covered to attend court hearings, to appeal, initiate, defend and prosecute any criminal act through their legal representatives only with the concurrence of the Attorney General (Legal Information Institute, 1). Any commission has rules or rather laws under which it operates. For the case of the Consumer Safety Product Commission, there are a number of laws which regulate its operations. To start with, in circumstances where there is

Anti war Movement Essay Example | Topics and Well Written Essays - 1000 words

Anti war Movement - Essay Example The strength of the movement lay also in the fact that it moved past the politics of the Cold War despite being temporally located in the heyday of this ideological and military struggle between the two power blocs. The democratizing potential of this is apparent since it brought the world together in movement that was humanitarian and anti-authoritarian at the same time (Frey, 2008). In fact, the basic objective of the movement was to abstain from siding with the ideology of either superpower. It is perhaps also significant that this moment coincided with the era of decolonization across the world where erstwhile colonized nations unwilling to compromise their sovereignty by aligning with Euro-American powers voiced their support for the cause of nuclear disarmament. It is important to note that the Campaign for Nuclear Disarmament in Great Britain far from being a sporadic movement had firm roots in the origin of the Cold War where several â€Å"international pacifists† who had organized strategic protests against the atomic bomb (Klimke 2012). The movement in Great Britain may thus be viewed as a successful culmination of the many efforts aimed at disarmament. 2. What role has internet played in the anti-Iraq war protest? The protest against the Iraq War, much like its precedent, the Nuclear Disarmament movement, was based in international cooperation. The protest also witnessed the extensive of use an entirely new medium of expression-the internet. The internet had certain obvious advantages over the more traditional methods of voicing dissent-it could bring together people and their opinions on a common platform without necessitating physical movement over long distances and significantly, authoritarian censorship is more difficult to impose on the internet than in protest marches and demonstrations. Pickerill and Webster in their essay â€Å"The Anti-War/Peace Movement in Britain and the Conditions of Information War† discussing the idea of â€Å"Information War† which denotes both â€Å"weaponry† which makes use of computer technology for greater precision in combat and attack, as well as the â€Å"symbolic realm† where ideas and images are employed to convey specifically targeted meaning. While the intensity of casualties rose steadily in war propelled by the â€Å"microelectronics revolution,† this also meant that there was extensive media coverage of the war which in turn conferred onto people the knowledge hitherto denied them to generate anti-war sentiments (408-10, n.d.). It is interesting to note that unlike most of its predecessors, the anti-Iraq War movement did not cease to operate after the ostensible end of the war and continued to protest in the subsequent years against the insidious ways in which military occupation and economic depletion have perpetuated Western control over Iraq’s political freedom. This too was perhaps made possible because of the internet which kept the memory of the war through the many blogs and websites which advertise their cause in numerous pages that an average internet user is likely to visit. Pickerill and Webster however warn against the debilitating effects of using the internet for anti-war protest as well as they argue that the sweeping generalizations on the internet often assume a homogeneous readership, eliding thereby the

Beyond Products Case Study - Entrepreneurship Course Essay - 1

Beyond Products Case Study - Entrepreneurship Course - Essay Example In his design, Peter Van Riet considered the disadvantages and advantages of the two early and most popular designs which developed the product to be a better choice for snowboarders. Being himself a semi-professional snowboarder, Peter Van Riet was able to identify the need of professional and recreational snowboarders for a more comfortable and safe design. Another vital strength of the company was that it was free from financial constraints and had enough capital available from the four business angels. Beyond Products is recorded to possess few technical limitations which should be eradicated before the trade fair of 2006 which raises the challenge of successful launch for the company founders. From the commercial point of view, the company also possesses the weakness of dependence on loan with high interest rates. Further development of the product requires huge amounts of working capital which is estimated to be acquired from bank loans and further investments from the business angels. Thus, this will increase the liability of the company and hamper its financial strength to an extent. The snowboard market is recognized to be a rapidly growing market in the United States, European Alpine regions, Japan and other niche areas. The number of customers is recorded to grow in these key regions which can enhance the growth prospects of the product as a preferable design for the professional and recreational customers. There are only a few players in the market acquiring a proportion of the entire market share providing huge opportunity for new entrants. The overall market prospect is also recognized to be favorable for the launch of a fresh snowboard binding. Most of the well-recognized companies in the target market also emphasize upon the other categories of the industry product line. Furthermore, the companies also focus on sponsoring famous professional snowboarders for brand promotion which is stated to be quite significant for

The Overall Concerns Of Resource Depletion Environmental Sciences Essay

The Overall Concerns Of Resource Depletion Environmental Sciences Essay Recently, people become very concern about the environmental issues. Our environment is our surrounding, its a gift that we have to keep , take care of and serve. One of the main problems that facing the globe is resource depletion .Resource depletion either it was for non-renewable or renewable sources, it has negative influence in both society and economy. Depletion of resources will make them very expensive. Or even after years from now we will not find resource to pay for .Many institution raise this problem up to aware people about this risk, a suggested solution is renewable energy. We should start thinking about the next generations. Renewable energy will be always there, there is plenty of it for present and future, especially because the world is facing continuous growing in population which is considered the main reason for resource depletion. Abstract: In this report we started by explaining the meaning of resource depletion. We mentioned some causes of this problem. The main three parts of resource depletion that we choose are fossil fuel depletion, water depletion and forest depletion. For fossil fuel we suggested renewable energy technologies as solution. We choose to talk about solar energy, wind power and hydroelectric power. For the water depletion we show how water is important .Also we discussed some methods to maintain water which are reclaimed water, solar desalination and rainwater harvesting. The third type is forest depletion and we suggested recycling as solution The meaning of resource depletion: Resource of depletion; its an economic word which mean all natural resources that divided between renewable resources and non-renewable resources, have been exhausted within a region. Using the resources beyond its rate we thought any replacement for it is considered as resource depletion. The human nowadays use resources without care about if they can find it in the future for the new generation. The depletion of natural resources continues which have 11.8% of global environmental problem. An average of 23% of Imagine lands soils are degraded to the extent that their productivity is limited. 1% every year of the countrys forested area is going down. There are water shortages, and 100 high plant species are threatened during the dry seasons. Because of expansion and intensification of agriculture, among others also for reasons of commercialization and increase of global trade the pressure on the natural resources will increase. A lot of resources in the world have been decline a very year, such as fisheries, tropical forests, water, fossil fuels (oil, natural gas and coal) and materials. The first report to the Club of Rome, The Limits to Growth, was published in 1972. It marked the beginning of modern environmental policy. The report highlighted the impossibility of sustaining exponential economic growth and its associated Resource Depletion (1). The environmental policy has change to other policy filed in the twenty-five years after Limits to Growth, as example as we have released that the plenty resources of coal in the world, we cannot fully exploited because of the climate Change. Despite this the threat of Resource Depletion is still continue. Focusing on the mineral oil during the first and second oil crises (1973-1974, 1979) has been replaced by a wider picture of resources including groundwater, energy, land, fertile soil, forests and fish stocks. One common aspect of these resources is their depletion may have economic repercussions. Causes of resource depletion: Excessive or unnecessary use of resources Non-equitable distribution of resources Overpopulation Slash and burn agricultural practices, currently occurring in many developing countries Technological and industrial development Erosion Irrigation Mining for oil and minerals. Types of resource depletion: Fossil fuels depletion: The fossil fuels are very important key for energy in the world and for modern economic, which is non-renewable resource that takes a million of years to create. The fuels are; oil, coal and natural gas. It is 86% of the world of global energy supplies nowadays. Fossil fuel helps to produce cheap energy that modern industries depend on it. It can be burned and producing significant amounts of energy per unit weight .Also, it is primary source of the cheap energy that powers our modern Industrial Civilization that depends on it such as; automotive Industry, steel Industry and transportation Industry. Nowadays we are facing a huge level crisis in energy. Any careful examination of the writings and papers of the worlds leading energy scientists will convince the reader of the validity of the fossil fuel energy crisis. The U.S. Department of Energy Projects tell us; the demand of fossil fuel energy will increase approximately 60% between 2006 and 2030 globally. The energy crisis is caused by the depletion of fossil fuels. From the graph you can see the depletion of world fossil fuels energy from 1900 to 2300. The Industrial civilization cannot exist without oil. The prices of the oil have drawn attention to the issue of the relative supply and demand for basic oil that has a central place in the modern economy. The Knowledge of petroleum geology has made great advances in recent years. It transpires that the bulk of the Worlds current production comes from deposits formed in two brief and exceptional epochs, 90 and 150 million years ago. This tells us that oil is a finite resource, which means that it is matter to depletion. Is the oil running out? Yes, we started when we produced the first drum. But Running Out is not the major issue as the resource will not be finally exhausted for very many years. The important question that we should have answered it is: when will production reach a peak and begin to decline? Gas depletion you can see from the graph the amount of natural gas used between 1965 and 2004. This is look as depletion because gas is burned much more quickly than it is formed. There are limited natural gas reserves. During the 40 year period, the gas equivalent of almost 60 billion tones of oil was used up. The region that used the most gas over this period was the United States, the Russian Federation, the Ukraine and Canada. Nearly all the natural gas that has been burnt as fuel was burnt during these forty years, and the years since. Until about 1965 natural gas from oilfields was often considered hopeless, so was disposed of by flaring. It has since been used widely, as a fuel. Water depletion: Water is other important resource for irrigation, drinking, cleaning and in every part of the global. There are too kind of water; Groundwater and surface water. The water depletion is very important issue after the fossil fuels depletion because of decreasing in clean and fresh water in some location and areas. The United Nations Global Environment Outlook have Four reports estimate, a third of the worlds current population will live in areas with water shortage by 2025, while the remaining two-thirds are expected to be under water stress that mean almost 2 billion people. That means there will be no enough water in the future for sustain agriculture, energy production, industry and domestic life at all. The groundwater is an important resource throughout the world for some country especially US; it supplies many of the human needs. It is the source of drinking water for about half the total population and nearly all of the rural population, and it provides over 50 billion gallons per day for agricultural needs in the United States. A lot of area in the United States they have groundwater depletion. What mean Groundwater depletion? Groundwater depletion is a term that defined as long-term water-level declines caused by sustained groundwater pumping, is a key issue linked with groundwater use. We can compare water stored in the ground with the money that kept in a bank account. Pumping water out of the ground faster than it is replenished over the long-term cause a problem. The volume of the storage water in the ground is decreasing in many areas especially in the United States because of pumping. Groundwater depletion is primarily caused by sustained groundwater pumping and pumping g roundwater at a faster rate than it can be recharged can have some negative effects of the environment and the people who use the water, such as: drying up of wells reduction of water in streams and lakes deterioration of water quality increased pumping costs land subsidence The chart shows monthly-mean water levels from 1964 to 2003 for a well in Cook County, sourthwest Georgia. The well is used for irrigation and public-supply purposes and offers a good visual representation of long-term groundwater declines due to excessive pumping7. Forest resources depletion: The Echo systems help sustains life for millions of species. It is the forests that provide a home for a large majority of the species alive. Therefore the most important species are trees in these forests. There are many benefits that we can get from forests some of these benefits are; cleaner drinking water, a home for plants and animals, economic growth, clean air, recreational opportunities, reassuring future. Also there is another benefit we can get from trees is called oxygen. We would not be able to live If there were no trees to give us oxygen to breath. So this is a very important reason to protect forest which is staying alive. Forests have many resources that people can use to raise their living standards. For example; the wood for building houses and paper making. Some wood materials last a long time so they keep the house warm and make it easy to manufacture homes. Unfortunately the overpopulation and the demand for a higher standard of living are constantly increasing. Therefore the demand for more resources is increasing to levels that cannot be sustained any more. Since forests provide a large of resources to the worlds, so many forests are cut down or burned, because human demand and greed Look around yourself right now and you will find a product within your reach that is made of wood. The cause for cutting down forests and depletion is directly associated to manufacture paper products and lumber for other manufacturing like furniture. We use wood for everything in our live. It is used in home building, furniture, marine products and the list seems like its endless. Not only wood is good building material, but also has great aesthetic qualities. Unfortunately we dont always take in to account how many trees need to be cut down so we can have luxuries furniture in our lives. Another direct cause for forest depletion is simply burning forests for farmland. Many poor farmers burn or cut small area from the forests in some countries so they can have room for farming and cattle, these countries are undeveloped and have tropical rainforests. But the problem in the big scale is created when thousands of square acres a year burned by huge corporate farms. They need this much area to provide farming on a much larger scale to compete in the world market for food. The reason forests are burned is due to the rich minerals fertility of the soil. Some farmers in undeveloped countries they dont have any education in how they can re-use the soil. So that the soil is use up and left as a desert, while they burn and cut more forest to make another farm. The Amazon rainforest which located in South America is the largest in the world has fallen to be victim of deforestations. Also, as another example of country that has fallen to be victim of deforestations is Brazils mar ket which is the third of all the Latin countries. The Brazils foreign debt, except in the most unlikely of positive economic conditions, is simply unsustainable in the further years. The economical pressure on a country is an additional cause that forces a country to deforestation such as the case in Brazil. The data shown from 1978 to 1988 that 230,000 square miles was affected from deforestation, by Basic Science and Remote Sensing Initiative (BSRSI). That is 16.5% of the entire rainforest in the Amazon. The farming is another example shows the cause of deforestation. Between 1990 and 2001 the percentage of Europes process meat imports that came from Brazil rise from 40 to 74 percent according to the Center for International Forestry Research (CIFOR). By 2003 the growth in Brazilian cattle production-80% of which was in the Amazon-was mostly export driven, for the first time ever. As more roads are built to provide access to forests in undeveloped countries more deforestation will appear. As we side before about the benefit of the forests .We get a large part of our oxygen from plant such as trees and most of the trees live in forests. It is important for human to understand the problem with deforestation may have on our air quality. The gas that has an impact on the greenhouse effect is Carbon dioxide (CO2). There is a cycle between CO2 producers such as cars and CO2 consumers such as plants called the Global Carbon Cycle. The tropical forests hold 460-575 billion metric tons of carbon worldwide in the plants and soil. From 1850 to 1990 deforestation worldwide released 122 billion metric tons of carbon into the atmosphere, with the current rate being between 1.6 billion metric tons per year. Therefore deforestation plays a significant role in Global Warming and clean air. Also, another problem with deforestation is a decrease in biodiversity. The biodiversity is important for Ecosystem sustainability, agriculture, medicine and recreation, aesthetic and commercial val ue. There are about 5 to 80 million species that live on this world. The tropical rainforests are home to more than half of the species living in the world. After deforestation, many species cannot live and possibly go to extinct. For many resources we depend on these species, so their extension will take from us their benefits. The solution: For fossil fuel depletion: Renewable energy: Because what fossil fuel coal, oil and natural gas cause to our environment and because the scientist warn of decreasing of amount of fossil fuel. We need to use other sources to provide energy both for present and future generations. There are other alternative which give billions of people the energy they need more than that, it consider to be clean and low-carbon energy systems and they will never run out .these alternative are renewable energy such as solar energy ,wind power ,geothermal ocean energy, biomass and hydro energy. In this report we will concentrate in solar energy, wind power and hydropower which are clean sources and clean technologies. Different type of renewable energy varies according to the cost, local conditions and performance These sources of energy can replace fossil fuel. Reported from the European Renewable Energy Council 2004 said that renewable energy could provide the power needs, and supply 50% of the worlds energy by 2040. Not only have that, but renewable energy technologies dont produce greenhouse gases emissions and can addressed climate change. Japans Ministry has a study about the Environment; conclude that renewable energy could reduce greenhouse gas emissions to a level a 70% reduction by 2050. The graph below show the use of worldwide energy for all energy types .The Graph 2 show the expected future behavior by the EIA (Energy Information Administration) it shows that oil and coal will keep increasing. Nuclear power will increase but will not lead. While the condition of renewable energy is uncertain. They think that it capacity will explode. Graph 2: worldwide energy use by energy Type. Solar energy: Sunlight or solar energy sends out every day from the sun .is the most form of renewable energy. The usage of solar energy in renewable energy technology it either direct heat buildings and water and to generate electricity. or indirect because the heat from the sun cause the movement of the wind which we take benefit from it in wind power ,also it provide trees the main source to grow which used in biomass energy more than that sun light cause the evaporation which makes hydropower happen. The direct use of solar energy dont cause pollution in air or water more than that it is available everywhere on Earth. The light reaches us from the sun by two different radiation types. One of them reaches earths surface in an unbroken line which called direct, while the radiation that spread by clouds, dust, humidity and pollution is called diff. .so we have two technologies for the solar energy. One of them uses mirror to concentrate the direct radiation. PV cells and other solar technologies for diff radiation. Know if we want to ask ourselves why solar power? Because it doesnt bring co2 in one hour sun shine, the Earth receives more energy than human put away in whole year. Also, the Sun has enough helium mass to supply the Earth with energy for another five billion years. The Americas Department of Energy said that, if solar panels placed on 0.5% of USAs mainland landmass, it could grant for all of its electricity needs. It is true that solar energy is five times the fossil fuel price, but once it is applied it pay for it self The Environmental Impact of Solar energy technologies do not cause pollution, some thermal energy technologies need cooling by water, which can be recycled. Only small amounts of unsafe substances are formed in the manufacture of photovoltaic cells and CSP equipment. For the land required Most PV systems are installed on existing structures such as homes and buildings which doesnt need extra area . but CSP plants need large land, For example, One CSP plant near Las Vegas covers 400 acres and can produce 64 MW of electricity. Which is enough to power 15,000 homes annually. The cost of the solar energy decrease but it is still expensive. In U.S 2006 trade electricity prices for all sectors averaged 8 cents per kWh, and for housing electricity, the price averaged about 10 cents per kWh. But CSP systems generated electricity at a cost of 12 cents per kWh, while PV systems generated electricity for about 18 to 23 cents per kWh. PV systems usually generate more electricity during the hottest time as shown in the graph3 . And this is another advantage of solar energy. In Texas, the need is at peak in the summer because of air conditioning when the solar source is maximum. More than that, the most need for electricity is in the later afternoon period when existing solar energy is high. Graph 3: percentage of generate electricity by solar system among the year The Solar Electricity, to convert the solar energy to electricity. There are two ways which are photovoltaic and solar thermal systems. The name of Photovoltaic is from the words photo which means light and the word volt, the short of photovoltaic cells is PV cells or solar cells. Some example of PV which change sunlight into electricity in Solar-powered toys, calculators, and roadside lights as shown in the Figure1. Figure 1: PV cells The wide use of PV cells because it made from silicon material, it is the same material that makes up sand and it is the second most widespread material on earth. PV cells can provide power to anything that is powered by batteries or electrical power. Also because the transfer of sunlight into electricity happen silently and right away Solar Thermal Electricity, It has two names as well solar thermal systems and concentrated solar power (CSP), It also convert solar energy to electricity, but in a different way. This way need solar collector with mirror in order to gather the sunlight onto a receiver that heats a liquid. Then the hot liquid create steam to generate electricity in the same way of coal plants as shown in Figure 2. the usage of this type is wide .In Mojave Desert There are nine solar thermal power plants which create 360 MW of electricity. Figure 2: concentrated solar power Wind power What is the meaning of wind? Wind is the movement of air. When it happen? It happen when hot air moves up and cooler air swap it. The energy of moving air used long time ago in sailing and ext. Nowadays wind energy generates electricity by capturing the wind in wind turbines. How it happen? Wind power is in fact a form of solar power, it caused by heat that comes from the sun. Solar radiation causing the Earths surface to be warm and it heat the water, sand and stone at day time and it cool at bight. The hot air move up and that cause reduce in the atmospheric pressure near the surface of the earth which make the cooler air replace it. This movement called wind. The energy caused by the wind power is Clean and Renewable energy. It uses natural and infinite sources. More than that it doesnt cause pollution or waste The Energy caused by the wind is relative to the cube of wind velocity. The equation of wind power is the following: Power = density of air x swept area x velocity cubed , P =  ½.à Ã‚ .A.v3 velocity (v) is in m/s, at sea level (density of air is 1.2 kg/m3) the power density in the wind will range from 10W/m ² at 2.5m/s (a light breeze) to 41,000W/m ² at 40m/s (a hurricane). In general, wide areas have annual wind speeds below 3m/s this number is not useful for wind power system. For the area which have annual wind speeds more than 4.5m/s wind power will be economically useful. That why this source of energy is more economically practical in windy areas. In fact the energy which produced by a wind turbine can increase by 20% for each 10% increase in wind speed. The graph 4 below show that when wind speed increase the power output increase proportionally. Graph 4:the relationship between wind speed and power output. The world-wide require for wind turbines has been raising quickly over the last 15 years. In 2001 the wind energy industry set up 5,500 MW power generators. More than 24,000 MW of wind power is now expected to be in action around the world .the graph 5 below shows the increasing in depending on wind power throw the years. Graph 5: increasing of wind energy use. Turbines used to cover the demand of electricity. so , the size of the turbine enlarged from 100 kW to 1 MW of electricity generation power, even residential offshore as shown in the Figure 3 below. Figure 3: 2 MW Wind Turbines at 40 MW Offshore, Windfarm in Denmark. Hydropower The word Hydro means water. Moving water have energy and that what we call it Hydropower. Technology has made this energy to be able to change it to electricity. The force of Gravity, which attracts the objects and drags them down, it, pulls the water from high land to lower land. This water which falls down has a power. More than that, Water is a renewable source, because of the continuous cycle of evaporation and precipitation. But how this cycle happen? it always start from the sun , The heat of the sun reaches to water in the earth surface , and that lead to evaporation in ocean and other water surfaces and form clouds. After that the rain or snow falls down to earth, and drains into rivers and streams that run again to the ocean. As in the figure 4 .This moving water could power water wheels that operate mechanical processes, and captured by turbines and generators. The cycle of water is always there, it will not run out. Figure 4: water cycle. We imitate the natural behavior of moving water. By building dam in a river in order to capture the water, then it will formulate a big lake at the back of dam. We this lake is called a reservoir. When the water allowed moving by opening the dam it will run down and operate the huge wheels of turbine. From the power we get in this process we can generate electricity. Hydropower has more than 92 % among renewable energy as shown in graph 6 .It is commonly among developed countries around world. About 150 countries, nowadays there are around 2,000 dams in U.S only. Graph 6: amount of electricity generated from different types of renewable energy. In order to have continuous supply of electricity in an interconnected grid which rely in both wind and hydropower technologies. Hydropower can be used to cover for wind power and vice versa. That means when there is no wind, we can depend on hydropower. Also when there is low water period we can use wind to generate power usually generated by the hydropower systems. For water depletion: Why save water? Many people say, we dont have t consider water lost because water is covering 71% of the earth. However, most people dont know that this percent dividend to 1% for freshwater, 97% is too salty for human use, and the rest is frozen, and Figure 5 show how hard it is to find freshwater on earth ether it is ground water or iced. This sum up the 1/3 of the worlds population is already facing problems due to both water shortage and poor drinking water quality, and the UNESCO has predicted that by 2020 water shortage will be a serious worldwide problem. So, who is responsible to save water? Farmers, governments, engineers and people, they all play an important role to save water. Figue 5: Water distribution on earth in precentage. Governmental efforts: Some governments around the world developed an environmental policies and guidelines, some of them is provide water efficiency regulation. Their main policy is to sustain natural recourse such as water, and any sustainable development that serves future generations economically, environmentally, and socially. Examples for these organizations: The Australian National Water Quality Management Strategy (NWQMS) The Indian Ministry of Water Resources. The Quà ©bec Ministry of Sustainable Development, Environment and Parks U.S. Green Building Council The UNICEF Estidam Water sector in the United States USGS UN-HABITAT The Millennium Development Goals (MDGs) à ¢Ã¢â€š ¬Ã‚ ¦etc All of these organizations tend to improve the sustainable developments in their regions. Sustainable water There are soo many ways to sustain water, and we are going to discuses some of the known methods to maintain water. Reclaimed water: Is a term used for recycling water. Rather than dispose wastewater -sewage and greywater-, reuse it in non-potable uses, such as irrigation, dust control, and fire suppression. However, this reclaimed water need to follow up in some procedure to make it applicable to use. Wastewater treatment process, it is the process of removing physical, chemical and biological contaminants from sewage and wastewater through physical, chemical, and biological processes, to manufacture an environmentally safe fluid suitable for disposal or reuse. And from figure 6 we can study the treatment process: Preliminary Treatment It is a physical process by using devices to remove or cut out large objects such as inorganic solids, oil and greases; to protect pumping equipment and facilitate subsequent treatment processes from damage these object can do. Examples for these devices: Screens Comminuting devices (shredders , cutters, grinders) Grit chambers Preparation tanks   And chlorination is needed in preliminary treatment.   Primary Treatment After Preliminary process, some suspended solids still contained by the treatment water, it is removed by physical process of sedimentation through a sedimentation tanks which hold the treatment water for 2 or 3 hours, and the suspended solids -sludge- settle on the tank are removed with mechanical scrapers and pumps. And the floating sludge are removed by surface skimming equipment. Secondary Treatment In this stage a microorganisms are involved to remove dissolved organic matter from what remained in the wastewater. These microorganisms feed on organic matter from sewage as their energy supply. Final Treatment In the final treatment chorine is add to remove all pollutants from the water, and the product is usable water. Figure 6: Waste-water treatment process. Solar desalination Desalination is a method to remove salt and minerals from water (ocean). Solar is referring to the energy used for this process. There are two types of solar desalination: Reverse Osmosis Its a simple operation of water desalination, through applying pressure to the sea water in one side of the system through a membrane and salt is essentially filtered, with a mathematical. This method used in large-scale desalination implementations where electricity is less costly. Here, solar energy is collected and converted into electrical or mechanical energy to initiate the process. From figure 7 we can explore the process. Figure 7: Reverse Osmosis process The solar humidification-dehumidification (HDH): Also called the solar multistage condensation evaporation cycle (SMCEC) or multiple-effect humidification (MEH), is a technique that simulates the natural water cycle on a shorter time frame by evaporating using solar energy (sun) and condensing water to separate it from other substances. And the condensed water is collected in a chamber. As shown in figure 8. Figure 8: the HDH process Rainwater harvesting Is a very simple system of collecting rainwater before it reaches the aquifer through the storm water harvesting, which is a surface especially prepared for this purpose, such as buildings roof, and ground; to reuse it as drinking water, irrigation, water for livestock, and any other apply. However, this system is not suitable for every where, where it is used in areas with an average rainfall greater than 200  mm/ year. first water is collected via the storm water harvest (roof), then transfer through gutters and pipes which includes sufficient incline to avoid standing water, and strong to carry large amount of rainwater. Storage tanks should be covered to prevent mosquito breeding and to reduce evaporation losses, contamination and algal growth. Figure 9 conclude the procedure. Figure 9: Rainwater harvesting system For forest depletion: Why save forest? Cities, massive projects, farmlands, factories, firewood, tables, books, newspaper à ¢Ã¢â€š ¬Ã‚ ¦etc. What is there origin? Forest. Through history human activities destroyed and deforest the forest around the world, cities such as Ur, Uruk, and Babylon contributed deforestation massively of surrounding areas, which are forest. Agriculture, in the other hand, was one of the main reasons of forest deforestation, in order to use it to harvest. So why we should concern about forest and protect it? Well, if there is no forest, there is no trees and plant, no trees no species, no ecosystem, and no reduction of carbon sinks; which lead to a bigger problem known as global warmingà ¢Ã¢â€š ¬Ã‚ ¦ Facts: once forests covered14% from land surface; and now they cover only 6%, and if it is keeping in that track its going to be more decrease in this percentage, as the Forest transition theory Predicts, as shown in Graph 7. Graph 7: The forest transition theory Because of the massive developing and industry, every 1 sec there is a loss of about one and one-half acres of rainforest. The major authorities to blame are governments, multi-national logging companies, and land owners. <

Skills Of Table Tennis :: essays research papers

  Ã‚  Ã‚  Ã‚  Ã‚  Table tennis is played on thick wooden or composite wood, plastic and even metal varieties table. The surface of the table should have a mat finish and it is usually dark green or blue. The table is 274 cm in length, 152.5 cm in width, and 76 cm in height. The table is divided by the net into two courts. The net is 15.25-cm height and extends 15.25 cm beyond each side of the table. The racket consists of two parts: the rubbers and the blade. There are a lot of different kinds of rubbers and blades. There are offensive, all-round and defensive ones. The player style will dictate the kind of racket to use. A game is won by the first player or pair (in doubles play) to score 21 points, unless the score reaches 20-20 in which case the player or the pair needs two clear points more than the other in order to win the game. A match consists of the best of three games or in big tournaments, like World & European Championships, the best of five games. You lose a point when:  You fail to make a good serve.  You fail to return the ball from the opponent.  You hit the ball before it has bounced on your side.  The ball bounces twice on your side.  In some special occasions when you execute the serve. A good return is a single hit of the ball by the racket hand below the wrist, after it has bounced on the player's side of the table, so that the ball returns directly on the opponent's side. Of course the ball is permitted to hit the net during the return. However if the ball hits the net during the serve, the serve is executed again. The server changes every 5 points. This continues until the player wins the game. After the end of the game the opponents change sides and the player who served first in the previous game, serves first in the next. In doubles the rules of serving and changing ends are the same as in singles except that the serve is executed from the right hand side. Each 5 points the server changes corner with his partner so that the other will be ready to receive the opponent's serve. In doubles play the ball is returned in a strict sequence. The server serves and then his partner receives the ball from the opponent and so on.

Schools Should Ask Students to Evaluate Their Teachers

Nowadays, education is at the top of people’s concern. Most of schools consider the interaction between students and teachers as an important role in the teaching process. Therefore, it leads to a policy that students can evaluate their teachers. In my opinion, I support that idea for several reasons.First of all, students are the very people who receive knowledge and lessons from their professors directly thus their evaluations must be exact and appropriate. In fact, it is very difficult to ask people to evaluate something that they never experience by themselves. As an example, customers are always the accurate measuring device of products’ quality because customers often try to find the best product among a lot of ones in the market to use. Similarly, students will express true opinions about their teachers and those opinions are very helpful for schools to know their teachers better. In this way, schools can have right methods to improve their staff.Furthermore, eva luations from students will make teachers perform their tasks better. As teachers know that their students always consider their teaching methods and their profession in every lecture or discussion, they will be stimulated to do well at the class. Besides, students’view will help teachers to find out their most effective teaching way and thus, their skills and experience can be boosted to a higher level.Finally, asking studentd to evaluate their teachers is also a way of showing concern to students. By that way, the schools indicate that they really appriciate their students’opinions and feeling. Hence, students may feel more comfortable and free. Also, when evaluating teachers, students have to pay attention to their lessons and they may realize their attitude of studying as well.To sum up, I strongly believe that schools should ask students to evaluate their teachers. That idea will help both of students and teachers to do better in their tasks. Schools Should Ask Students to Evaluate Their Teachers Nowadays, education is at the top of people’s concern. Most of schools consider the interaction between students and teachers as an important role in the teaching process. Therefore, it leads to a policy that students can evaluate their teachers. In my opinion, I support that idea for several reasons.First of all, students are the very people who receive knowledge and lessons from their professors directly thus their evaluations must be exact and appropriate. In fact, it is very difficult to ask people to evaluate something that they never experience by themselves. As an example, customers are always the accurate measuring device of products’ quality because customers often try to find the best product among a lot of ones in the market to use. Similarly, students will express true opinions about their teachers and those opinions are very helpful for schools to know their teachers better. In this way, schools can have right methods to improve their staff.Furthermore, eva luations from students will make teachers perform their tasks better. As teachers know that their students always consider their teaching methods and their profession in every lecture or discussion, they will be stimulated to do well at the class. Besides, students’view will help teachers to find out their most effective teaching way and thus, their skills and experience can be boosted to a higher level.Finally, asking studentd to evaluate their teachers is also a way of showing concern to students. By that way, the schools indicate that they really appriciate their students’opinions and feeling. Hence, students may feel more comfortable and free. Also, when evaluating teachers, students have to pay attention to their lessons and they may realize their attitude of studying as well.To sum up, I strongly believe that schools should ask students to evaluate their teachers. That idea will help both of students and teachers to do better in their tasks.

The Lion King the Realm of the Wild essayEssay Writing Service

The Lion King the Realm of the Wild essayEssay Writing Service The Lion King: the Realm of the Wild essay The Lion King: the Realm of the Wild essayAll through the Lion King Disney cartoon one can observe the beauty of African landscapes: jungles, deserts, plains and many more. The nature is depicted through lively colors and amazing animated sunsets. The very first sequence gives a tone for the remainder of the movie. One can observe a marvelous sunrise and a vast variety of animals that move over shadowy plains passing spectacular waterfalls with a multitude of flamingos. All of the animals are approaching the rock to give honors to the newly born lion king who is to rule all ranks of creatures. The sequence shows how chivalrously the animals bow to honor the new ruler. Africa in this motion picture is depicted as a splendid landscape where all sorts of animals live and interact with each other. The theme park depicted in the movie is comprised not only of all sorts of plants and animals, but the whole objective world. This is how nature is improved upon in this animation.Nature here f orms the entire content as the film itself is meant to be about wildlife and landscape in particular. It is significant to mention that this movie combines a vision of Arica as total wilderness and complete absence of human characters (Finch 90). Another way of how Disney improved upon the nature lies in the fact that this movie is somewhat uneasy in relation to such natural aspect as the circle of life. Although it clearly shows that it is possible and natural for a lion to eat other animals, there are a number of jokes in regard to the food chain. Thus, the meals of Pumbaa and Timon are nothing else than brightly colored beetles and worms. This is what makes their eating habits different from the real world animals. And hyenas in the Lion King are the only characters that are depicted as eating other animals. However, taking into account that hyenas in the movie are shown as living in shadowy and dark places, they are defined as being something opposite to natural. In fact, many a spects of nature in the movie including certain characters and places are seen as unnatural.The concept of family in this Disney’s cartoon is of great importance both in relation to the target audience and as a major factor of the corporation’s worldview. Family in this movie plays a central role as this animation is itself family oriented. It is highly appealing to children and instills the instincts of protection in parents. Parents and their children watch the Lion King together and this movie makes them think of all the pains of separation. The importance of family is the key point of the Lion King animation. It narrates about how the child is becoming adult and emphasizes the role of a father in the up-bringing of a son (Forgacs 369). Disney focuses on the fact that a father plays a crucial role in the way a son becomes mature and gradually enters the adult world. This aspect of father-son relations is vividly depicted throughout the whole movie.One of the most im portant family related aspects of the movie is the introduction of the period of adolescence lived through by a child as an individual experiencing certain crisis. It reflects the personal journey of a young child who faces a number of challenges and deals with various family related problems. The crisis is viewed as not touching upon the splits within the family, but rather emphasizing the very fear of the separation from the family and the fear of living in a non-complete family with only a single parent (Forgacs 370). It raises an anxiety related to the absence of the role model of masculinity in case of the single motherhood. The Lion King is a reflection of all these concerns and fears, thus emphasizing the importance of the masculine role model and the need of reconstructing the distorted family union. This is a significant social problem that exists even in the contemporary society. The Lion King focuses on a number of common concerns in regard to family crisis with a special emphasis on the relationship between a father and a son.Furthermore, the Lion King provides a strict hierarchical structure of animal ranks. Lions in this movie are presented as kings of the whole animal community. However, Simba’s father and uncle are depicted in a different way. The movie focuses on the depiction of physical attributes of the muscular and powerful father of Simba who rules over the whole animal world and his skinny uncle who governs the violent hyenas as outcasts of the animal community (Myers 47). The world of the Lion King is strictly structured, not only in relation to patriarchy, but the general hierarchically divided society which is based upon the life circle with the lions above all animals bearing the power of the kings. The movie is focused not only on the depiction of physical attributes of the lions, but also the hierarchical roles they play within the society. Thus, the Lion King exemplifies the conflict of powers that results in the victory of the greater good.Disney’s animation depicts the hierarchy where hyenas are viewed as outcasts of the society. They are a kind of a street gang that lives beyond the life circle. However, their leader is the lion as a representative of the upper class. This hierarchical conflict penetrates the whole narrative showing the clash between good and evil power. Uncle of Simba is viewed as evil, while his father exemplifies good. These two powers struggle against each other reflecting the eternal conflict between good and evil. The Lion King shows that the followers of the Simba’s uncle Scar are stupid and violent cowards. This is added with the effect of the movie’s authoritarian hierarchy existing in the natural world. The natural hierarchies include those of the position in society and those exemplifying gender differences (Schickel 152). On the basis of these hierarchies, the morals and values are vividly depicted throughout the movie. In this regard, it needs to b e said that the perception of the environment has greatly changed over time and the Lion King movie shows a totally different attitude to the natural world and wildlife.The visual imagery of the Lion King represents the culmination of realistic aesthetics in animation that started with the introduction of Bambi, Snow White and True Life adventure series in the 1930s. All of Disney’s animation movies rely on the live-action tendencies which are the signature of the traditional realistic narrative. The three-dimensional characters, depth of short, movements of characters and zooms in Bambi, Life True adventures series and the Lion King follow two tendencies that are the simplicity of graphics and the thoroughly detailed naturalism (Myers 47). All this is what makes these movies so reflective of each other. The previous portrayal of the wildlife in Disney cartoons was somewhat simpler but at the same time more natural. In this regard, the Lion King differs from the previously re leased Disney animations.

Facebook and Social Networking essays

Facebook and Social Networking essays Social Networking was designed for the initial purpose of making communicating with long distance friends, relationships, family members, co- workers, etc. a whole lot easier. Although this statement still holds true, it's a wee bit harder to find it through all this "fluff". What is this "fluff" exactly? This "fluffy" unnecessary goodness which just like candy is fun, colorful, easy to get, and completely unnecessary for our rotting youth. In hopes of correlating my evaluation essay to my proposal essay, I'm hoping to achieve the proposal for a separation of Facebook. Still being controlled under one site; I would like to propose two forms of Facebook- a Facebook for businesses and the strictly commercial use of Facebook, which represents the Facebook we have today. As a look back to the many problems/issues that arrive with this popular website, here is a little review: just like any other product in the world, the need to constantly change and stay updated to keep things fresh and interesting is in order to stay, well up to date; but do these set of "rules" apply to popular networking sites such as Facebook? Facebook was originally designed by a Harvard student hoping to be able to connect with people on his campus via the Internet. As the years went on it was available to other colleges, which set Facebook apart from other sites such as MySpace, Xanga, and Friendster. Facebook could not be accessed by just anybody; it was strictly designed for high school and college students who were listed under the set list of schools that Facebook recognize (Yadav). When looking at how Facebook was designed back then, to what it is now, it's almost a complete turn around. Although the main purpose is still present, it's hard to uncover behind all these flooded applications. These applications vary from games, to picture editing software, to finding your "top stalkers." But with all of these a...

Develop the film Hot Fuzz (Edgar Wright, 2007) Essay

Develop the film Hot Fuzz (Edgar Wright, 2007) - Essay Example Simon Pegg, as well as, Edgar Wright has also acted in several films, thereby contributing towards enlightening the community through creation of awareness, education, as well as entertainment in global levels. The film stars Pegg as well as Nick Frost. In connection to the above, it is also of paramount importance to acknowledge the other characters who contributed to the establishment of the film entitled Hot Fuzz. Other than the listed above, the other people who contributed to the establishment of the film called Hot Fuzz includes Nira Park. It is of crucial significance to acknowledge the fact that Nira Park was the main producer of the film. Other than Nira Park, the other co-producers of the film entitled Hot Fuzz comprised of both Tim Bevan, as well as, Eric Fellner (Stevenson, 12). It is important to note that these are also among the top ranking personalities in the filming industry. Thus, they have made significant impacts in the film industry in the United Kingdom, thereby contributing towards enlightening the whole world through entertainment as well as awareness creation through the film actions. It is of crucial significance to understand the fact that the film entitles Hot Fuzz talks about two police officers who attempted to offer a solution to a series of social ills, involving offering solutions to a series of deaths that took place in mysterious manners in the English village. In the film, the English village has been depicted as one of the most unfriendly environments, full of criminals who can the levels of others in mysterious manners. The people inhabiting certain sections in the village are notorious criminals in the society, thereby linked to the causes of the mysterious deaths. As a result of the above, it was the responsibility of the police to determine the hidden information that formed the baseline of such mysterious deaths. Relevant to the above, the police officers did the much they could as observed in the film.

Death Penalty in the United States Assignment Example | Topics and Well Written Essays - 1000 words

Death Penalty in the United States - Assignment Example Bessler argues, throughout the book, that the American death penalty is not only cruel but also unusual. Bessler claims that the United States’ persistence with the death penalty is simply an escapist measure to avoid dealing with its socioeconomic problems. This article is one of the most intriguing and critical pieces of the American judicial system and death penalty. Boys, a recognized authority on criminology, contends that the death penalty is a retrogressive policy that the country would be better off without. Boys also compare America’s stand on the death penalty to other countries’ citing the fact that it is one of the few world powers that still practice this ‘draconian† policy that is an inhumane solution to managing crime. Brown begins his article by stating that the United States is lagging behind most countries in the world when it comes to the death penalty. In an era in which most countries are abolishing the death penalty, America is still using capital punishment as an excuse for mitigating social and economic problems. Brown also states that the death penalty is a policy that the United States should leave in the age of the founding fathers. In this thought-provoking book, Deger delivers a critical take on capital punishment in the United States and Great Britain. In America, Deger delves into the history and evolution of the death penalty to date, and its impact on American society. Deger argues that the death penalty is nothing more than a blatant disregard for human life that is perpetuated by a fear of change. Lyon begins his book with a discussion of the history of capital punishment in the United States and then delves into an examination of the reasons the death penalty is a constant in the judicial system of most US states.