fuel cell technology :: essays research papers

Fuel cell technology 1 Running head: FUEL CELL TECHNOLOGY: TRANSPORTATION AND RESIDENTAL/ COMMERICAL APPLICATIONS Fuel Cell Technology: Transportation and residential/commercial applications   Ã‚  Ã‚  Ã‚  Ã‚   Monique University 2 A fuel cell is an electrochemical energy conversion device. A fuel cell converts the chemicals hydrogen and oxygen into water, and in the process it produces electricity. With a fuel cell, chemicals constantly flow into the cell so it never goes dead as long as there is a flow of chemicals into the cell, the electricity flows out of the cell. Most fuel cells in use today use hydrogen and oxygen as the chemicals. Fuel cell provides a DC (direct current voltage that can be used to power motors, lights or any number of electrical appliances. The fuel cell will compete with many other types of energy conversion devices, including the gas turbine in your city's power plant, the gasoline engine in your car and the battery in your laptop. Combustion engines like the turbine and the gasoline engine burn fuels and use the pressure created by the expansion of the gases to do mechanical work. Batteries converted chemical energy back into electrical energy when needed. Fuel cells should do both tasks more efficiently. Fuel cells improve battered powered cars and gasoline powered cars more efficiently. Fuel-cell-powered electric cars are powered with pure hydrogen. It has the potential to be up to 80% 3 efficient, and with today’s gas prices that would be wonderful. The efficiency of a gasoline-powered car is surprisingly low. All of the heat that comes out as exhaust or goes into the radiator is wasted energy. The engine also uses a lot of energy turning the various pumps, fans and generators that keep it going. So the overall efficiency of an automotive gas engine is about 20%. That is, only about 20% of the thermal-energy content of the gasoline is converted into mechanical work. The efficiency of an electric car is 72% for the car, 40% for the power plant and 90% for charging the car. That gives an overall efficiency of 26%. The overall efficiency varies considerably depending on what sort of power plant is used. If the electricity for the car is generated by a hydroelectric plant for instance, then it is basically free (we didn't burn any fuel to generate it), and the efficiency of the electric car is about 65%.   Ã‚  Ã‚  Ã‚  Ã‚   4 Efficiency is not the only consideration, however. People will not drive a car just because it is the most efficient if it makes them change their behavior.

Antitrypsin Deficiency: The Genetic Disorder

Alpha-1 Antitrypsin Deficiency (AAD) was first described in 1963, and of the five patients identified, three were found to have severe emphysema at an early age. Subsequent studies that the deficiency was inherited, and in most of the early studies, emphysema and chronic bronchitis were common features.The deficiency was shown to be associated with a marked reduction in the ability of the plasma to inhibit the serine proteinase trypsin, and later studies showed that this also reflected an inability of the serum to inhibit the enzyme neutrophil elastase (Pauwels, Postma, and Weiss, 2004 p.446). Human neutrophil elastase was shown to produce both emphysema and chronic bronchial disease in animal models. Emphysema can be directly inherited via a single gene defect. The genetic disorder, known as alpha-1-antitrypsin deficiency, results from a defective gene transmitted by each parent equally to the affected offspring. This gene codes for the enzyme antitrypsin, which, when deficient, res ults in the loss of normal lung elasticity and in progressive overinflation and destruction of lung tissue.Antitrypsin deficiency is also the most common genetic cause of childhood liver disease (cirrhosis) and the most common reason for liver transplantation in children. A family history of early onset emphysema or childhood liver disease points toward this diagnosis, which can be confirmed by DNA analysis. DNA testing can be used to detect carriers of alpha-1-antitrypsin deficiency as well as to facilitate prenatal diagnosis for a couple found to be carriers, who face a 25 percent risk of having an affected child (Millunsky, 2001 p. 128-129). Scope and LimitationsAAD is one of the rarest diagnosed conditions in our current time; hence, focused study of such condition is essential. The case study involves the subject of pathological conditions linked with the condition of progression of defective genetic manifestations. Utilizing physiological and genetical approach, we shall cente r into the discussion of the disease causation, processes and manifestations involved. It is indeed essential to employ the principles of wellness and its components. The following shall be utilized in the overall study. A.To be able to determine and elaborate the actual disease processes involved, as well as the disease conditions manifested B. To be able to relate genetic causalities and factors in the aspects of disease progression utilizing the domains, components, and principles of wellness C. To be able to provide necessary health interventions, suggest enhancing lifestyle modifications and preventive behaviors related to the condition imposed Purpose of the Study The value significance of this study provides awareness to the public especially in terms of what can these contributing factors impregnate to the condition occurrence.Most likely, the degenerative character of AAD is very much rehabilitated if this awareness is enhanced through education. The study mainly expands he alth awareness on both AAD patients and non-patients who are greatly may or otherwise exposed in factors that contribute to its genetic occurrence. Moreover, the knowledge on this topic may further aid the patients and those involved in the reduction of anxiety and ignorance of the condition imposed. Discussion The Functions of ? 1-Antitrypsin and Involved MediatorsBlood and other body fluids contain a serum protein classified as an alpha-a globulin that is capable of neutralizing trypsin and many other proteolytic (protein digesting) enzymes such as fibrinolysis and thrombin (Bross and Gregersen, 2003 p. 39; Crowley, 2004 p. 399). This specialized protein is called alpha-1 antitrypsin, and its concentration in the blood is generally determined. Most individuals produce normal amounts of antitrypsin, others are severely deficient, and a third group have subnormal levels of this protein (Crowley, 2004 p. 399).?1-Antitrypsin (AA) is an inhibitor of serine protease in general but its m ost important targets are neutrophil elastase, cathepsin G, and proteinase 3, proteases released by activated neutrophils. Several line of evidence suggest that inhibition of these neutrophil proteases is the major physiologic function of AA (Bross and Gregersen, 2003 p. 39). †¢ First, individuals with AAD are susceptible to premature development of emphysema, a lesion that can be induced in experimental animals by instillation of excessive amounts of neutrophil elastase.These observations have led to the concept that destructive lung disease may result from the perturbation of the net balance of elastase and AA within the local environment of the lung. †¢ Second, the kinetics of association for AA and neutrophil elastase are more favorable, by several orders of magnitude, than those for AA and any other serine protease. †¢ Third, AA constitutes more than 90% of the neutrophil elastase inhibitory activity in one body fluid that has been examined, pulmonary alveolar la vage fluid (Suchy, Sokol, and Balistreri, p. 549).AA is the archetype of serine protease inhibitor (SERPIN) supergene family. Its primary function is inhibition during the host response to inflammation/tissue injury, for which it has been termed a hepatic acute-phase reactant (Suchy, Sokol, and Balistreri, p. 549; Bross and Gregersen, 2003 p. 39). AA acts competitively by allowing its target enzymes to bind directly to a subrate-like region within its reactive center loop. The reaction between enzyme and inhibitor is essentially second order, and the resulting complex contains one molecule of each of the reactants (Bross and Gregersen, 2003 p.39; Fessler, reiley and Sugarbaker, 2004 p. 155). A reactive-site peptide bond within the inhibitor is hydrolyzed during the formation of the enzyme-inhibitor complex. Hydrolysis of this bond; however, does not proceed to completion (Suchy, Sokol, and Balistreri, p. 549). The predominant site of synthesis of plasma AA is in located biologically in the liver wherein in most clearly shown by conversion of plasma AA to the donor phenotype after orthoptopic liver transplantation (Bross and Gregersen, 2003 p.39; Suchy, Sokol, and Balistreri, 2007 p. 551). It is synthesized in human hepatoma cells as a 52-kDa precursor; undergoes post translational, dolichol phosphate-linked glycosylation at three asparagines residues, and undergoes tyrosine sulfation. It is secreted as a 55-kDa native single-chain glycoprotein with a half time for secretion of 35 to 40 minutes (Suchy, Sokol, and Balistreri, 2007 p. 551). The absence or insufficiency of AA initiates genetic anomaly in terms of failure to suppress immunity response (Porth, 2007 p. 501).

Teen Pregnancy Essay - 915 Words

Teen Pregnancy Over the past two decades, the rates of teen pregnancy have grown dramatically. According to the Prevention of Teen Pregnancy, approximately every thirty-one seconds ateenager becomes pregnant in the United States. This is unbelievable, however that is the truth that no one can deny. Many people think that teen pregnancy dont effect them unless they get pregnant or one of the family members in teenage get pregnant. However teen pregnancy really affects our communities and country. Approximately, over eighty-five percent of teenage girls who become pregnant every year do not plan their pregnancies and only fifteen percent of pregnancies are prepared. The causes of teen pregnancy is unsafe sex or poor sex education in†¦show more content†¦Sometimes they will get support from their parents and some of them do not. Therefore, they have to go out and find the jobs, which will only pay minimum wages. Most of teen mothers will drop out from high schools because they have to find a job so that they can survive. The chances of getting a good pay job will be very low because they dont have high school degrees. Sometimes they cant even support themselves and even more they have to take care and take responsibilities for another life is totally a mess. Furthermore, some teen fathers will ignore their babies and refuse to support teen moms and babies. Only ten percent of teen mothers will get married and most of them become single parents. Usually teen marriage work and end up with a divorce. For instance, one of my best friends Mary got pregnant in her seventeen and got married. By the time when she got pregnant, both of them did not have a job and they havent graduated from high school yet. They have to drop out from high schools because Mary has to give birth and her husband had to go out and work in order to support the family. However, he couldnt have a good pay job because lack of education. She had to worry about family and suffered through all of pains and troubles while I was only worried about what I have to wear to school tomorrow, where to go and have fun and sometimes worried about school works. By looking at them, I thought it was very unfair to her new born child becauseShow MoreRelatedTeen Pregnancy1426 Words   |  6 PagesIntroduction Teen pregnancy is often unplanned and challenging for the future life of mother and child. The increase risk of health problems for both mother and baby occur during teen pregnancy. Teen pregnancy impacts adolescent development in all aspects: physical, emotional, cognitive, and social development. 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Or why is the teen birth rate in Massachusetts 19Read MoreTeen Pregnancy : Teenage Pregnancy1404 Words   |  6 PagesLauryn Jones Block 5 4/27/16 What is Teen Pregnancy? Teenage pregnancy is pregnancy in human females under the age of 20. A girl can become pregnant from sexual intercourse after she has begun to ovulate which can be before her first menstrual period, but usually occurs after the onset of her periods. In well-nourished girls, menarche usually takes place around the age of 12 or 13. Most teenage girls don t plan to get pregnant, but many do. Teen pregnancies carry extra health risks to both the motherRead MoreTeenage Pregnancy And Teen Pregnancy1057 Words   |  5 PagesTeenage pregnancy is a common thing here in America. It seems teens are getting pregnant more than the average married couple. There are some risk factors teen moms face and there is also another great turn outs. There is a major difference between the two. It’s important to tell teens the turnouts of teen pregnancy for the good and bad parts. There are risks of having sex, teen moms can make a difference for her and the baby, the risk of having HIV and/or any other STD’s, and the effects on theRead MoreTeenage Pregnancy And Teen Pregnancy1341 Words   |  6 PagesTeenage pregnancy is a prominent dilemma in our nation because it continues to place adolescents into delinquency. According to the United States Health and Human Services, three out of ten American teen girls will become pregnant at least once before they reach the age of twenty. That is nearly 750,000 teen pregnancies in a year (1) (HHS Pg.2 2014). Also according to U.S. Department of State, teen pregnancy budgets the United States and tax payers approximately seven billion dollars annually (2)Read MoreTeenage Pregnancy And Teen Pregnancy1664 Words   |  7 PagesTerrazas English 4 Miss Stahlecker 4 November 2015 Teenage Pregnancy According to cda.org, in 2013, a total of 273,105 babies were born to women that were in between the ages of 15-19 years old. Teenage pregnancy is a major concern in today’s society. This paper will talk about teenage pregnancy, statistics, ways to prevent teenage pregnancy, and after birth options. So why is teenage pregnancy so important? Some people are concerned about teens getting pregnant at such an early age. There are otherRead MoreEffects Of Teen Pregnancy On Teens1643 Words   |  7 PagesEvery teen has dream about how they want to graduate from high school and then go to college, but some teens are not willing to take the challenge. Some of these teens want to drop out of high school and other teens want to keep furthering their education. For some there are obstacle that life throw at them to be able to accomplish their goals. Earning an education is challenging enough, but when there is a teen parent trying to finish their education it becomes more difficult than it would beRead MoreThe Effects Of Teen Pregnancy On Teens978 Words   |  4 Pagesare getting younger in age, and the birth rate is rising higher. Mississippi has the highest birth rates in teen pregnancy, and has held this title for the past few years. This problem has had such a rise to fame becau se this is a problem that can be prevented. Parents and communities should take action to help lower the teen pregnancy birth rate in Mississippi. Since the birth rate in teens is so high that means there is more need of government assistance. This becomes such a problem in states because