Tuesday, August 20, 2019
Pros and Cons of Tidal Energy
Pros and Cons of Tidal Energy As the worlds energy crisis progresses, renewable energy sources like tidal power are being explored. Tides, the rise and fall of sea levels, are created by changes in the gravitational forces of the sun and moon as well as the earths rotation. Tidal Energy is generated by converting gravitational potential energy of high tides into hydroelectricity. Most ocean environments experience two high tides and two low tides everyday. There are three main ways to harness tidal energy, each with their own pros and cons. The first method of tidal energy generation is the tidal stream generator, the second is the tidal barrage and lastly there is dynamic tidal power. Tidal energy is not yet widely used but many people believe that it has great potential for future energy generation. This paper will examine the environmental effects of the different methods. The concept behind the tidal stream generator method is very similar to that of an underwater windmill; as the tide flows in and out of a bay it spins an underwater turbine which generates power. Tides move slowly, but because water is much denser than air, it can move much slower while providing the same power. The environmental benefits of this technology are numerous. Tides are always either flowing in or out allowing tidal stream generators to supply constant, consistent and emission free power. This is a benefit over other the other methods of tidal generation that can only generate power when the tide moves in a specific direction. Also, tidal stream generators are much, much cheaper than other methods of tidal generation allowing them to be easily implemented and tested. Although very few studies have been done, it would seem fish avoid the turbines used in tidal stream generators resulting in almost no aquatic fatalities. This means tidal stream generators have no known impacts on the surrounding ecosystem. There are not many environmental disadvantages to tidal stream generators. The turbines may cause some minor disruption to aquatic animals, but this is yet to be proven. The only environmental damaging aspect of this technology would be the work involved with maintaining and installing the underwater turbines. However, as a relatively unknown source of power, there is much of time for improvements. The tidal barrage is a large dam-like structure built at the mouth of a bay, stream, or estuary which experiences a large tidal range. It allows water to flow into the basin through the sluice gates during high-tide and during low tide releases the water through turbines. Turbines trap the energy from the movement of water in and out of the basin. This method of collecting energy has many environmental benefits. Firstly, because tides come twice a day, a tidal barrage will supply predictable, consistent and emission free power. This method is able to collect more energy than tidal stream generators because it essentially converts the potential gravitational energy of the tidal range in an entire region into electricity. Although barrages are expensive to build, they can be conveniently built under existing bridges. This reduces cost and some impact on the natural surroundings. There are, however, many environmental concerns with this kind of operation. Barrages have a great effect on the surrounding ecosystem. One of the main problems with the construction of a tidal barrage is it can halt the flow of saltwater into and out of estuaries. This can negatively affect the resident marine life. Also, migrating fish are only able to pass through the sluice gates as the basin fills with water. When the gates close, the fish will swim through the turbines. Currently even the safest designed turbines kill fifteen percent of the fish that pass through. This can have a signification effect on the fish population. Finally, tidal barrages block sediment movement. This can causes an accumulation of sediment around and in the barrage which could impair its functionality. Also, by blocking sediment movement it decreases the turbidity in the basin allowing for an increase in phytoplankton which effects the food chain of the ecosystem. Lastly there is dynamic tidal power, a promising new idea with great potential. A large barrier, perpendicular to the coast, is built out from the shore and an adjoining barrier is built along the far end of the first barrier making a â€Å"T†shape. This barrier blocks the acceleration of the tides parallel to the coast creating a difference in the water levels on each side of the barrier. A series of turbines installed in the dam can convert the potential energy of the higher water into electricity. The main difference between this source of tidal generation and the others is that to be economically viable it must be over 30 km in length. This is because the power output is proportional to the square of the dam length. The idea was proposed by Dutch coastal engineers Kees Hulsbergen and Rob Steijn. It has only been tested in computer simulations. Dynamic tidal power like the other types of tidal generation is emission free and resource independent. The environmental benefits of this method over the others boil down to the huge amount of energy that can potentially be generated in coastal regions. Even though it must be built on such a large scale, simulations project that it could potentially generate and 8GW of installed capacity which is thirty percent more power than the Bruce Nuclear Generating Station. If two are built around 200km apart an almost constant stream of power can be generated. Also beneficial is that the dams dont require a naturally high tidal range like both tidal barrages and stream generators. So countries like China, Korea, and the United Kingdom could potentially generate huge amounts of power. It is estimated China alone could generate over 100 GW of power. The environmental risks of dynamic tidal power is mostly in the construction of such a large structure. The building of something so massive wastes a lot of fossil fuels. Also, a barrier of that size could disrupt migration patterns of aquatic animals. Although as the barrier does not seal anything off sea creatures can always swim around. Each method has its own benefits and detriments. Tidal Stream power although not harming to the environment returns the least power, tidal barrages have the capability for large scale power generation they can hurt the ecosystem they are uses in, and dynamic tidal power which can be used to generate large amounts of power in many coastal locations is very very costly to implement and has never been tested. One method does not replace the other as they all are operate in different conditions. Development of this new technology is important and must be continued.
Monday, August 19, 2019
Gandhi Was One of the Greatest Men to Ever Live Essay -- Indian, Revol
I am going to try to answer an interesting question as to who is the greatest man in the world today. In seeking an answer to this inquiry, I predict that people would first instinctively go back to the days of the great wars in history, and go over the names of the men who held positions of vast responsibility and power in that astonishing conflicts, people who succeed in front of their task and, thus, were considered heroes. However, I turn away from the storm of wars, and from the men who rode that storm to power and place; and I look further for that man who impresses me as the greatest man who lived in the world. A man, who people can surely call the greatest, should be a universal man  a man who combines in perfect balance the supreme qualities of an idealist and a realist, a dreamer and a doer. The man who satisfies those qualities, I believe is Mohandas Karamchand Gandhi, the Indian leader, of the great revolutionary movement against British rule in India. He is better known as Mahatma, called by his own countrymen first, meaning â€Å"the Saint†. Gandhi was born on second October, 1869 in India, of a rich, clever and cultivated family. He was reared as the sons of such families are always reared, possessed of everything that money could buy (Gandhi: A Biography). On September 29, 1888 he went to England to study law at University College London. He took his degree in regular course, returned to India, but failed to become a successful lawyer in Bombay and Rajkot. At the same time, he already found that religion was coming to have a dominant place within his life. Even before his journey to England, he had taken the vow to abstain from wine, flesh, and sexual intercourse, and on his return to India, his asceticism in... ...crowds of people were gathering in order to hear his words. He seems to be was a person whom the Indians saw in him, perfect and universal man. He had a simple, altruistically and uncorrupted personality. In his political duties he was a firm realist, consistently working towards a goal of liberation; while on the other hand, he was an idealist, living ever in the pure happiness of the spirit. Works Cited "Gandhi: A Biography." Kamat's Potpourri. 4 Jan. 2011. Navajivan Trust. 13 Feb. 2011. . Holmes, John Haynes. "Mahatma Gandhi: an American Portrait." Harvard Square Library. 2006. Harvard University. 12 Feb. 2011. . Moncur, Michael. "Mahatma Ghandi Quotations." The Quotations Page. 1994. 12 Feb. 2011. .
Identify and Discuss Examples of Good/Bad Practice in the Management of
According to the UK Association of Project Management (APM) quoted in Atkinson (1999), it has produced a UK Body of Knowledge (BoK) which provides a broad definition for project management as: â€Å"The planning, organisation, monitoring and control of all aspects of a project and the motivation of all involved to achieve the project objectives safely and within agreed time, cost and performance criteria.†The planning of the project firstly consists of identifying and clarifying the tasks and necessary resources required for completing the project; the organisation phase or scheduling then allocates how much time is needed to complete each task, and finally the monitoring tracks progress and analyses performance and quality (Spinner, 1997). Time and cost management are both the most commonly used and important project management functions and are strongly linked with the level of success of the project. These are predicted during the planning phase of the latter; time, cost and quality are so closely linked that they form what is called the â€Å"Iron Triangle†(Atkinson, 1999). This assignment will thus first shed light on the Fourth Bridge and Bath Thermae Spa case studies respectively, and will then be structured around three primary skill and managerial elements contained within the Project Management Body of Knowledge. According to Cramb (2008), renovating the bridge located near Edinburgh is a â€Å"never-ending job†due to its length, given that as soon as maintenance crews have finished renovating it, it is time to start again. In 2002, civil engineering company Balfour Beatty signed a maintenance contract of  £10 million per annum for Network Rail till the estimated end of contract in 2009 (Forth Bridges Visitor Centre Trus... ...rison, F. and Lock, D. (2004) Advanced Project Management: A Structured Approach. 4th edition. Aldershot: Gower Publishing Hendrickson, C. and Au, T. (1989) Project Management for Construction: Fundamental Concept for Owners, Engineers, Architects and Builders. 1st edition. New Jersey: Prentice Hall McManus, J. (2010) ‘Keeping projects under cost control’, The Chartered Institute for IT [Online]. Available at: http://www.bcs.org/server.php?show=conWebDoc.5912 (Accessed 01 December 2010) Spinner, M. P. (1997) Project Management: Principles and Practices. London: Prentice Hall International Thermae Bath Spa (2010) Project History. Available at: http://www.thermaebathspa.com/newsandinfo/projecthistory/ (Accessed: 30 November 2010) Wikipedia (2010) Forth Bridge [Online] Available at: http://en.wikipedia.org/wiki/Forth_Bridge#Maintenance (Accessed: 24 November 2010)
Sunday, August 18, 2019
Christian Reformation :: Religion, History, Informative
The Protestant Reformation           Many ideas of the Renaissance like humanism, individualism and secularism stimulated a strong critique of the church ´s policy and the clergy ´s behaviour. Many people regarded it as a scandal that the catholic church sold indulgences. Indulgences were documents, stamped by the church which could reduce your sins. People who bought indulgences believed that this document could pave their way to heaven. In northern Germany they went so far that they even sold indulgences which could reduce the sins which you are going to commit in the future. They also sold indulgences for the salvation of somebody ´s dead relatives.      Martin Luther a German priest, who lived in the small city of Wittenberg was the the most famous critic of the corrupt practices of the Catholic church. He wrote his critiques down in 95 theses on a door of a church in Wittenberg. These 95 theses spread quickly all over Germany and parts of northern Europe. The first reaction of the catholic church was a reduction of the sales of indulgences. But this sale was not the only point Luther criticized in the Catholic church. The Catholic church taught that salvation comes from faith, good deeds and the assistance of the church. Martin Luther ´s concept was that salvation comes by faith alone. Martin Luther also translated the bible into German. So far the bible was only written in Latin and the most people could not read it. For Protestant people the bible was the only source of truth.      After a long argument between Luther and the church Luther was excomunicated from the church in the year 1521.
Saturday, August 17, 2019
Anorexia, bulimia and related eating disorders treatment Essay
Anorexia and Bulimia Introduction            In the United States, millions of people are affected by severe eating disorders which are sometimes life-threatening. Bulimia nervosa and Anorexia nervosa are the most common destructive eating disorders. Over 90% of those individuals who are affected with these eating disorders are youthful women. About 1% of the young girls develop anorexia nervosa, which is a risky condition where those girls can starve themselves literary to death while another 2% or 3% of youthful women get bulimia nervosa, which is also a vicious pattern of extreme overheating which is usually followed by vomiting among other â€Å"purging†behaviors. Anorexia and Bulimia have gotten to epidemic proportions. For instance, a new study conducted by NEDA (National Eating Disorders Association) revealed that 50% of girls have noteworthy eating disorders during their teens. Anorexia and bulimia obviously are severe disorders that require and necessitate serious at tention. Nevertheless, many individuals are not knowledgeable regarding the disorders; therefore do not distinguish warning signs most of the times until when it is too late. Anorexia and bulimia are destructive eating disorders which can have adverse effects on human beings if not well treated (Buckroyd & Rother, 2008).            Anorexia nervosa refers to a disorder in which individuals starve themselves intentionally. The disorder, which usually begins in young individuals around the puberty stage, involves excessive weight loss. Different from normal dieting, which ends after the desired weight is attained, in anorexia weight loss and dieting persists until the sufferer is below normal limit for height and age. Numerous anorectics appear to be emaciated however are certain that they are suffering from overweight. The most frightening aspects of this disorder is that individuals suffering from anorexia continue perceiving that they are suffering from overweight even when they become bone-thin. In this regard these individuals get scared of gaining extra weight due to the unknown reasons. Bulimics also have this fear (Retrieved March 17, 2004, from http://www.nice.org.uk/nicemedia/pdf/CG9FullGuideline.pdf).            As eating disorders usually develop in adolescence stage, they can blight social and physical development and numerous sufferers are unable to achieve their academic potential. A mood which is depressed is a frequent feature, partially because of these unfavorable effects and also due to the distressing nature of key warning signs of these disorders. Adverse physical effects of dieting, purging behaviors and weight loss are critical and usually prove to be fatal. In fact, anorexia has the highest rate of mortality of any adolescence psychiatrist disorder (Espejo, 2012).            Approximately 40% of anorexics start developing the bulimia disorder later. Bulimia nervosa differs a bit from the anorexia since individuals suffering from bulimia don’t shun eating. Instead, people with bulimia usually consume huge food amounts over short period of time after which they get rid of the eaten food quickly through taking diuretics or laxatives or vomiting. Bulimia is 2 or 3 times more prevalent compared to anorexia and is also more common in females compared to males. Nevertheless bulimia has an effect slightly on older age group, frequently women who are in their early to mid-twenties who were overweight during their childhood. Since many bulimics â€Å"binge and purge†in top secret and maintain body weight which normal or above normal, they can habitually hide their disorder successfully from other individuals for many years. The bulimics challenging eating pattern is an uncontrollable and compulsive one th at results to chemical imbalances in their bodies. These imbalances lead to depression, clouded thinking and lethargy (Retrieved March 17, 2004, from http://www.nice.org.uk/nicemedia/pdf/CG9FullGuideline.pdf ).            Both bulimia and anorexia when severe can lead to colon damage, constipation, muscle spasms, irregular or loss of menstruation, seizures, urinary tract infections, kidney dysfunction, chronic indigestion and strain on most of the organs of the body. The bulimia vomiting practices can result to a ruptured stomach, swollen salivary glands, erosion of dental enamel and also chronic sore gullet and throat. The anorexia malnutrition also has its own effects which include; growth of hair all over the body which is down-like, severe cold sensitivity and inability to concentrate and think rationally. Both bulimia and anorexia have severe physical effects which are reversible if dealt with during the early stages. Nevertheless the diseases are deadly and it is imprudent to disregard the warning signs and delay the treatment. In a case where the disorders are unattended, they can take away quality of life of an individual or even life altogether (Re trieved March 17, 2004, from http://www.nice.org.uk/nicemedia/pdf/CG9FullGuideline.pdf ).            Eating disorders consist of a variety of syndromes including social, psychological and physical features. Even as the acute physical impediments of these disorders might arouse immense concern in health care staff and family members, bulimia nervosa and anorexia nervosa are often chronic conditions having considerable long –term social and physical sequelae, from which recovery turn out to be complex. Long-term disabilities comprise negative effects on fertility, parenting, relationships and employment. The impact of an individual’s eating disorder on family life and home is usually significant and family members might carry a great burden over a long time. Frequently family members are at a loss to be acquainted with how to assist and offer support to a relative who is affected (Retrieved March 17, 2004, from http://www.nice.org.uk/nicemedia/pdf/CG9FullGuideline.pdf).            Various different ideas exist concerning the causes of anorexia and bulimia disorders and it is essential to recognize that not all these ideas apply to all the sufferers. Royal college of psychiatrists records on its website the potential causes of bulimia and anorexia; they include control, depression, puberty, social pressures, upsetting events and family. Social pressures for individuals to be thin are usually brought on by newspapers, magazines and television that are filled with pictures of men and women who are slim and attractive. Many individuals have a notion that they must look in accordance with the way the media enlightens them they look. Some individuals develop eating disorders since they perceive to be out of control in various aspects of their weight and life and what they consume is something which they can be able to control (Garner & Garfinkel, 1997).            The latest increases in prevalence and incidents of eating disorders can be accredited to both improved method of diagnosis and increase in number of cases. On the other hand, even with better eating disorder identification, numerous bulimics and anorectics do not look for assistance. Bulimia and anorexia are diseases that are often very quiet since they are not concerns that individuals like discussing openly. Receiving quality care during the early stages of the disorders is the predicator of an excellent outcome in bulimia and anorexia (Retrieved March 17, 2004, from http://www.nice.org.uk/nicemedia/pdf/CG9FullGuideline.pdf ).            Bulimia nervosa and anorexia nervosa are multidimensional and multifaceted; thus many experts have a perception that referral for professional assessment and assistance is necessary for people showing signs of eating disorders. According to college of Royal psychiatrists illustrates that recognizing that an individual is suffering from an eating disorder and also getting the treatment is challenging. Individuals suffering from anorexia have extreme and alarming weight loss but such sufferers will never admit that they have a problem. On the other hand, individuals suffering from bulimia usually feel ashamed and guilty of their behavior and may go on to greater extents with an aim of hiding it. Due to these reasons, all individuals should be knowledgeable regarding the warning signs of these disorders so as to distinguish them and reduce their existence (Friedman & Skancke, 2009).            In a case where it is recognized that a certain individual is a sufferer of either bulimia or anorexia or both, treatment is crucial. There are various different options when it comes to treatment which includes education, family therapy, possibly hospitalization, Cognitive Behavioral Therapy, psychotherapy, drug therapy and reality imaging. During therapy treatments, therapists assist the sufferers work to alter the unclear and inflexible thinking patterns relating to eating disorders. Mental health professionals’ efforts necessitate to be combined together with those of the other health professionals to get the most excellent treatment. Nutritionists give an advice on eating and diet regimes while physicians treat the medical complications (Lawton, 2005).            In conclusion, scientists have discovered that combination of medication and psychotherapy is also very effectual. There are no specific drugs approved for anorexia and bulimia, however numerous, including a number of antidepressants, are being examined for this use. Bulimics and anorectics can be perceived as dieting junkies and an effective treatment might be a drug which is regularly prescribed to the addicts (Espejo, 2012). A Detroit scientist examined Naltrexone, the drug which is given to do away with the heroin habit, in those women having bulimia and anorexia and established the drug to be productive. With the drug, the weight of the anorectics stabilized and bulimics essentially decreased their purges and binges. Effective treatment can save life of an individual with an eating disorder. Teachers, friends, relatives, physicians and relatives all play a great role in assisting the ill individual start and continue with a treatment program. References Buckroyd, J., & Rother, S. (2008). Psychological responses to eating disorders and obesity recent and innovative work. Chichester, England: John Wiley & Sons. Eating Disorders. (n.d.). Core interventions in the treatment and management of anorexia nervosa, bulimia nervosa, and related eating disorders. Retrieved March 17, 2004, from http://www.nice.org.uk/nicemedia/pdf/CG9FullGuideline.pdf Espejo, R. (2012). Eating disorders. Detroit: Greenhaven Press. Friedman, L. S., & Skancke, J. (2009). Eating disorders. Farmington Hills, MI: Greenhaven Press/Gale Cengage Learning. Garner, D. M., & Garfinkel, P. E. (1997). Handbook of treatment for eating disorders (2nd ed.). New York: Guilford Press. Lawton, S. A. (2005). Eating disorders information for teens: health tips about anorexia, bulimia, binge eating, and other eating disorders including information on the causes, prevention, and treatment of eating disorders, and such other issues as maintaining healthy eating a. Detroit, MI: Omnigraphics. Source document
Friday, August 16, 2019
Analysis of “Not Waving but Drowning” by Stevie Smith
Josh Robinson Dr. Joyce Huff ENG 206 Feb 5, 2013 Not Waving but Drowning People may not always be exactly what they seem on the outside just as a poem may have a deeper meaning than the story that is just on the surface. The poem Not Waving but Drowning by Stevie Smith is a great example of this. The author does a very good job at relating the death of a man by drowning and the reaction it causes in others to the deeper story of how the man is symbolically calling out to others who never come to help him get his life together.In the beginning of the poem, the first two lines are somewhat confusing. It refers to the main character as â€Å"the dead man†but then in the next line it mentions how he is moaning. This is confusing of course because as we all know, a dead man can’t make sounds. The next sentence though, seems more straightforward at first glance but as you move farther in the poem it’s meaning might not be so obvious. In the second stanza there is a ch ange from what seems to be the dead man speaking to others talking about what he was like when he was alive.It shows how, to other people, the man seemed happy, but it also seems as though the author means to give the impression that other people think that it was this one event that caused the man to finally break down. He says in the next stanza however that â€Å"†¦it was too cold always†which I think shows that he is saying that it was not merely one event that caused him to â€Å"drown†. His entire life consisted of reaching out to others for help but he never received it. In the beginning of the second stanza I would also like to point out how the author added â€Å"Poor chap†separated with a comma.I think the commas are likely used to emphasize that label that the author puts on the man from the viewpoint of others. It, in a way, shows how others may pity this man because of how great he had it until this single event. This is ironic because if you read the poem more than once, you’ll see that in the last stanza he is essentially saying in the third line, â€Å"I was much too far out all my life†, that he was suffering not only in the his last moments but throughout his entire life.If you look at the ways that the poem is written out, it kind of helps to separate the different clues that the author gives to you. In the very first line, it uses commas to separate â€Å"the dead man†. Even though it didn’t separate any of the other instances of the author referring to the man as â€Å"dead†, I think that it is written in this way so that you will realize that it might not mean dead in the literal sense of the word but in a more symbolic sense. As though to help that idea be emphasized each time that you come across that phrase.Also, if you noticed, â€Å"And not waving but drowning†was used both at the end of the first stanza as well as the end of the last stanza. In the first stanza i t is used merely as a way to get you to recognize the importance of it when it comes around again. It is placed here with the understanding that its true meaning may not be as clear until the next time that you see it. When you see it again though, you have enough information to where you can start coming to conclusions about what the author really meant to symbolize when he said that the man was drowning.In the second stanza, â€Å"They said†is placed in a line on its own which is unusual compared to the rest of the poem. It seems as if it was put there separately to draw attention to the contrast between what others thought of this man and how he knew his life to be as well as showing the importance of both it and the line before it, which is also abnormal in the fact that it is quite a bit longer than the rest of the lines in the poem. There are many poems that say one thing but completely mean another.Not everything is black and white in poetry just as in other art forms . Some may be more difficult than others to see a different meaning behind the text but through clever uses of words, imagery, and symbols just about any poem can be examined more closely for different meanings, thoughts, or ideas that the author is trying to convey. Poems should be broken down and examined in sections. Each section may have different clues as to what the author’s underlying meaning could be. This makes understanding the poem as a whole a lot easier.I found it very helpful in this poem (and other poems), as we learned in class, to read into things more and question everything. There could be a simple object that creates a completely different meaning to the poem once you find out it’s significance. Also, finding multiple definitions or even definitions you might not know such as the word larking was very helpful. I didn’t quite know the meaning of that word, but in looking it up, I basically came up with my entire argument for what I thought the meaning of the poem was.Figuring out a poem is almost like figuring out a puzzle. The only real difference is, the pieces aren’t cut out for you. You have to look at the bigger picture and find the logical pieces to cut out and then examine them individually. When you are done looking at them and figure out how to put them back together they could very well become a completely different picture from the one that you had originally broken down into pieces.
Thursday, August 15, 2019
Effects of Tire Pressure on Tire Inflation Essay
Despite concerns that global warming is a result of green house gasses emitted through burning fossil fuels, it is still prominently used for energy (Bent, Orr, & Baker, 2002). The energy harnessed from burning fossil fuels is used to do such things as produce electricity, power vehicles, heat homes and cook food. Oil is the most widely used fossil fuel and also the most widely consumed fuel (over nuclear and renewable) globally with a usage of 38% (Enzler, 2010). As oil resources depletes the prices rise and become more of a financial strain on every economy. The price of gasoline/ petrol, a product of crude oil used to power many vehicles is gradually rising. Gasoline prices in the Bahamas have risen to an average of $5.20 per gallon from $4.2 in 2005 (Turnquest, 2005). While the price of fuel (gasoline/diesel) is not in the average man’s jurisdiction to change, the use and wastage of it is. Although fuel plays a mojor rolle in powering vehicles to move a vehicle’s tires play an even more integral role in the overall performance of the vehicle, as it dictates its handling, traction, ride, comfort and fuel consumption; as it is the main component that interacts with the surface being driven on (Rezna, 2008). Thus if the condition of the tires is improper the performance of the vehicle will be affected. One negative tire condition that can occur is low tire pressure/ under inflation. According to the Webster’s dictionary, under inflation is the insufficient presence of air pressure in a tire for the amount of load carried and vice versa for over inflation. This paper will examine the causes of reduced tire pressure, the tire pressure in places abroad, effects of under and over inflated tires, and tire pressure as it relates to furl consumption. To begin with, tire pressure is a measure of the amount of air in a vehicle’s tires, in pounds per square inc h (psi) (Car Talk Service Advice: Tire Pressure, 2005). There is no standard psi for all tires however tires are marked with a recommended psi that should be adhered to for optimum performance in vehicles. Under inflation of tires can be cause by various factors such as natural causes and the negligence of drivers. Due to temperature and natural cause variation about 1 pound per square inch of pressure to 1Â ° degree Fahrenheit is lost every month (NHTSA, Tire Pressure Monitoring Final Part 3). This loss of pressure is known as natural leakage. Therefore, as the temperature of the climate or air changes, the pressure in the tire will change. Hence, under inflation of the tire will be increased. According to data from the tire industry, 85 percent of all tire air pressure losses are the result of slow leaks that occur over a period of hours, days, or months. Only 15 percent are rapid air losses caused by contact with a road hazard (Source). An example of the natural hazards that can be present that contribute to under inflation may be a nail present in the road that may puncture the tire (source if any). Additionally, due to the negligence of passengers to frequently check their tires under inflation can be an effect. As passengers frequently check their tire’s pressure they can decrease the rate at which the natural leakage of their tire’s air occurs. Moreover, A survey done by NASS-CDS crash investigators, in February 2001 identified that 39% of passenger cars and 46% of passenger trucks had at least one tire pressure that was 6psi or more below placard (recommended/labeled) pressure. In other words a considerable amount of passenger cars and almost half the passenger trucks tested were underinflated. The amount of cars surveyed and tested at this time was 5,967 passenger cars and 3,950 light trucks for a total of 9,917 vehicles across a total of 336 gas stations in the United States of America (National Automotive Sampling System Crashworthiness Data System, 2001). The below chart is a data collected from the NASS-CDS survey in 2001 and represents the percentages of passenger cars and light trucks and their amount of tires 20% or more below placard pressure. (National Automotive Sampling System Crashworthiness Data System, 2001) Number of Tires 20% or more Below PlacardPassenger CarsPercentLight TrucksPercent 199446.5%57436.7% 254825.744028.1 327512.922314.3 431914.932720.9 Total2,136100%1,564100% It is seen that a smaller percentage of vehicles (passenger cars and light trucks) had all four tires underinflated large amounts had at least one tire underinflated which can still affect the car’s performance. Additionally, according to an informal study done by students at Carnegie Mellon University, it was discovered that of the 81 cars they tested, the four tires of each car tested were underinflated by an average of 20% (Gearson 2005). Furthermore, with under and over inflated tires there are some effects that can impact the driver’s safety, the tire’s life expectancy, its rolling resistance and the use of fuel. Due to the loss of pressure in the tires, underinflated tires’ footprints or tread are enlarged. When the tire’s foot print is enlarged the rolling resistance of the tire is greater (Source). Rolling resistance can be defined as the friction between the road and the tire and the tire’s ability to effectively grip the road and ri de smoothly (source). Unfortunately, with an under inflated tire in the instance of wet roads, the tires are more likely to slide and cause accidents and crashes. Therefore, this result in a larger friction to overcome and more rubber of the tire burnt. Due to the lack of control over the vehicle the tread life of a tire can be decreased. According to Good year, a renowned tire manufacturing company, under inflated tires wears more rapidly than they should as compared to properly inflated tires (source). The company Good Year makes their tires out of rubber. This rubber is easy to burn and wear due to the pressure applied on an under inflated tire to carry a heavy load. As for over inflated tires, the tires cannot isolate road irregularities well, causing them to ride harsher (uncomfortably) (Proper Tire Inflation). This can also result in the traction and the tireprint/footprint of the vehicle to be reduced ( Rezna 2008). If the tireprint is reduced, this means that the surface contact area is reduced al so thus more pressure is being applied to the area in contact with the road. Inturn the tires are more likely to be damaged when running over potholes or debris in the road because the pressure applied from the weight of the car is greater. However, higher inflation pressures usually provide an improvement in steering response and cornering stability up to a point (Proper Tire Inflation). Moreover, over inflation can result in the transmission of shock loads by the tires to the suspension which can then diminish its ability to support the necessary load for cornerability, braking and acceleration (Rezna 2008). Finally, the fuel usage or consumption of vehicles is varied dependant on the pressure in the tires. This can account for at least one tire being under or over inflated. According to the National Research Council, the main factor associated with fuel consumption and tire pressure is rolling resistance. The make-up of a car also plays an important role in how fuel is consumed. The engine is directly connected to the axles that hold all four or more tires into place. The engine has to use this fuel to increase the transfer of power to the axles. As the fuel is inserted into the car, the engine then converts that fuel into mechanical energy and that energy is transmitted to the axles to turn the wheels (National Research Council, 2006). Therefore, if the tire is under inflated or over inflated the aero dynamic drag that is present between the tires and the road will place for strain on the engine to exert more pressure to move the vehicle and the fuel consumption will increase. Conclusively, there are many benefits that can be derived by monitoring and maintaining the correct tire pressure. They include improved fuel efficiency, better handling, better overall performance, overall safety, as well and an increased tire life span. In addition to these direct benefits, there is also the intangible benefit to the environment of decreasing green-house gases by improved fuel management. The overall benefit of this factor remains priceless. References Bent, R., Orr, L., & Baker, R. (Eds.). (2002). Energy: Science, Policy and the Pursuit of Sustainability. Washington, DC: Island Press. Car Talk Service Advice: Tire Pressure. (2005, April 29). Retrieved February 22, 2012, from Cars Talk: http://cars.cartalk.com/content/advice/tirepressure.html Enzler, S. (2010, March). Fossil fuels: Characteristics, origin, applications and effects of fossil fuels. Retrieved February 18, 2012, from Lenntech: http://www.lenntech.com/greenhouse-effect/fossil-fuels.htm Gearson, B. (2005). Carnegie Mellon Today: Save Gas, Money and the Environment with Properly Inflated Tires. Retrieved on 23rd February 2012 from http://www.cmu.edu/cmnews/extra/050921_tire.html National Automotive Sampling System Crashworthiness Data System. (2001). Tire Pressure Survey and Test Results. Retrieved February 22, 2012, from National Highway Traffic Safety Administration: http://www.nhtsa.gov/cars/rules/rulings/tirepressure/LTPW3.html National Research Council. (2006). Tires and Passenger Vehicle Fuel Economy: Informing Consumers, Improving Performance. Retrieved February 19, 2012 from http://onlinepubs.trb.org/onlinepubs/sr/sr286.pdf Proper Tire Inflation. (n.d.). Retrieved February 23, 2012, from Nitrogen Tire Inflation Systems: http://www.nitrogentiremachine.com/proper_tire_inflation.htm Rezna, J. (2008). Vehicle Dynamics: Theory and Application. Retrieved on 22nd February from http://books.google.bs/books?hl=en&lr=&id=Pvsv78xj7UIC&oi=fnd&pg=PR10&dq=under+and+over+inflatedness+in+car+tires&ots=1nBohNoAmt&sig=f0lQjo7DOYj_rim44o1xjewch8#v=onepage&q=under%20and%20over%20inflatedness%20in%20car%20tires&f=true pgs. Turnquest, P. G. (2005, August 17). Tribune. Gas price breaks $4 mark , p. 1. Car Talk Service Advice: Tire Pressure. (2005, April 29). Retrieved February 22, 2012, from Cars Talk: http://cars.cartalk.com/content/advice/tirepressure.html Enzler, S. (2010, March). Fossil fuels: Characteristics, origin, applications and effects of fossil fuels. Retrieved February 18, 2012, from Lenntech: http://www.lenntech.com/greenhouse-effect/fossil-fuels.htm Factors Affecting Truck Fuel Economy. (n.d.). Retrieved February 22, 2012, from Good Year: http://www.goodyeartrucktires.com/resources/factors-fuel-economy.aspx Proper Tire Inflation. (n.d.). Retrieved February 23, 2012, from Nitrogen Tire Inflation Systems: http://www.nitrogentiremachine.com/proper_tire_inflation.htm West,L. (n.d.). Keeping you tires Inflated could help save the planet, and your life. Retrieved on 23rd February 2012 from http://environment.about.com/od/greenlivingdesign/a/tire_pressure.htm Bent, R., Orr, L., & Baker, R. (Eds.). (2002). Energy: Science, Policy and the Pursuit of Sustainability. Washington, DC: Island Press. Car Talk Service Advice: Tire Pressure. (2005, April 29). Retrieved February 22, 2012, from Cars Talk: http://cars.cartalk.com/content/advice/tirepressure.html National Automotive Sampling System Crashworthiness Data System. (2001). Tire Pressure Survey and Test Results. Retrieved February 22, 2012, from National Highway Traffic Safety Administration: http://www.nhtsa.gov/cars/rules/rulings/tirepressure/LTPW3.html Population Change and Distribution. (2001, April). Retrieved February 2012, from US Census Bureau: http://www.census.gov/prod/2001pubs/c2kbr01-2.pdf Proper Tire Inflation. (n.d.). Retrieved February 23, 2012, from Nitrogen Tire Inflation Systems: http://www.nitrogentiremachine.com/proper_tire_inflation.htm
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