Diabetes Mellitus Essay -- Health, Diseases, Abnormal Insulin Secretio

Diabetes mellitus is a syndrome characterized by abnormal insulin secretion, derangement in carbohydrate and lipid metabolism, and is diagnosed by the presence of hyperglycemia. Also, this syndrome is common risk factors for chronic renal disease. Once it occurs, chronic renal failure and end stage renal disease often increase mortality in those with type 2 diabetes. A decrease in glomerular filtration rate indicates the development of renal disease, and early identification of this event is important in subjects with type 2 diabetes (1, 2). A new experimental diabetic syndrome in adult rats administered streptozotocin (STZ) and partially protected with a suitable dose of nicotinamide. This syndrome shares a number of features with human type 2 diabetes, and is characterized by moderate stable hyperglycemia, glucose intolerance, altered but significant glucose-stimulated insulin secretion (3, 4). Streptozotocin (STZ), a N-nitroso-N-methylurea derivative of 2-deoxy-D-glucose, is a diabetogenic agent acting through the selective destruction of pancreatic islet beta cells. It is known that insulin increases the transport of amino acid into the cell and increases the degradation of proteins. It causes changes in the levels of some amino acids. Thus, STZ has some effects on blood and urine amino acid levels. In addition, STZ displays nephrotoxic and hepatotoxic activity. It has been reported that STZ caused cataracts, necrosis of kidney tubules, mesengial proliferation and hyalines of vessels in rats (5). Extracts of Stevia rebaudiana Bertoni (SrB) have been used for the treatment of diabetes in, for example, Brazil, although a positive effect on glucose metabolism has not been unequivocally demonstrated. In addition to, oral intake... ...ation of intracellular area and aggregation of lipid in STZ diabetic rats (5, 16). Although in our study, the kidney cells of control groups showed normal cells structure, SrB treated diabetic groups had some mitochondrial swelling and vacuolization in thin section of kidney less than diabetic control and L-NNA treated diabetic groups. However, SrB+L-NNA treated diabetic groups had a normal mitochondria and organelle structure. We found that SrB and L-NNA treatment protect the kidney cells with decreasing blood glucose levels. As a result, the extracts of Stevia rebaudiana Bertoni leaves have beneficial effects on diabetes induced histological, ultrastructural and biochemical changes. It was determined that L-NNA is less efficient in the treatment of type II diabetes compared to SrB. Further studies of SrB concerning the treatment of diabetes appear warranted.

Gas Injection

In the production of oil from subsurface reservoirs, 65% of the oil initially in place (OIIP), on average, is left in the reservoir after more oil as possible has been recovered by natural depletion and with the aid of water flooding. Residual oil and gas are enhanced oil recovery (EOR) methods. EOR techniques are classified into thermal (such as steam or hot water injection) techniques and non-thermal techniques (including designer water flooding, gas injection and chemical flooding). The former is primarily intended for heavy oils, while the latter are normally applied in light oil reservoirs. There are some of the non-thermal enhanced oil recovery methods, such as polymer flooding, alkaline-surfactant-polymer (ASP) and alkaline flooding are much expensive and are also subjected to some operational restrictions, such as temperature (reservoir) and formation permeability. Gas injection techniques in various forms consisting of hydrocarbon gas injection (including natural gas, enriched natural gas and a liquefied petroleum slug driven by natural gas) and non-hydrocarbon gas injection (such as carbon dioxide, nitrogen and flue gas) are widely used to reduces the residual oil saturation. In gas injection, a compressed gas such as carbon dioxide (CO2), natural gas (consisting primarily of methane, CH4), nitrogen (N2), or flue gases are injected into the reservoir to displace oil toward the production wells. The injected gas either partially dissolves in the oil (immiscible gas flooding) or mixes completely with it (miscible flooding), leading mainly to swelling of the oil, viscosity reduction in the oil phase and also for miscible flooding, lowering of the interfacial tension (IFT) between the displacing phase and oil . CO2 injection is preferred because it applies for two different purposes; improving oil recovery and CO2 sequestration for diminish the greenhouse gases emissions. Several problems such as corrosion in the production wells or injection and surface facilities as well   , CO2 separation from the saleable hydrocarbons, large requirement of CO2 per increase in barrel and asphaltene precipitation which causes formation damage and wettability alteration have been reported for CO2 injection process. Injection of N2 or nitrogen-contaminated lean hydrocarbon gases are appropriate EOR processes for deep reservoirs, high pressure reservoirs, with light or volatile oil that are rich in light and also intermediate hydrocarbon components (C2–C5) due to their miscible displacement potential. Low cost, abundance and availability of nitrogen are the most reported advantages for nitrogen injection. Nitrogen is produced by cryogenic processes from air for a long period of time.CO2 (carbon dioxide) flooding enhances oil recovery by the following main mechanisms: (1) oil swelling, (2) reduction of crude oil viscosity, and (3) reduction of interfacial tension (IFT), the latter pertains to miscible flooding . The mechanism of swelling of oil by carbon dioxide injection which makes the volume of oil increase would help discontinuous oil droplets trapped in a porous medium to merge with the flowing oil phase. Reduction in the viscosity is another major mechanism which is significant at even moderate pressures. The amount of solution gas or oil ratio in case of nitrogen injection is lower than that of CO2. The swelling factors of N2 were also lower than those of CO2 due to nitrogen lower solubility in the oil. If the pressure is low (lower than 3 MPa), solubility of nitrogen and flue gas is negligible. The viscosity reduction due to N2 injection is much lower than that of carbon dioxide injection. Addition of N2 to the injection gas implies that some mechanisms other than swelling and viscosity reduction are important. One possibility is the buildup of free gas saturation with the N2 containing injectants that may decreases the relative permeability to water, thereby improving the mobility ratio. Moreover, nitrogen has a higher molar volume than CO2 which tells that one mole of nitrogen displaces a higher volume of gas than that of CO2. Therefore, N2 is more favorable in terms of displacement volume. So that our focus in this study is on N2.Literature review on N2 miscibility Immiscible gas injection can potentially recover a large amount fraction of the remaining oil after primary depletion or water flooding (WF). However, such potential has hardly ever been realized because of the low vertical efficiency and areal sweep efficiency. Nitrogen injection process is also performed either by miscible or immiscible, depending on the injection pressure of N2, reservoir temperature and reservoir oil composition. Miscibility is theoretically defined as the conditions at which there is no interface between the reservoir oil and displacing phase . In other words, it can be say that two phases are miscible when a single phase fluid is produced after intermingling of two fluids with each other at any ratio. The lowest operating pressure, at reservoir temperature, at which miscibility is achieved between reservoir fluid and injection gas is termed as the minimum miscibility pressure (MMP) . There has been a few correlations in the literature for N2 MMP estimation producing different average absolute error values. A study done by Fathinasab, Ayatollahi and Hemmati-Sarapardeh   had resulted in a correlation for MMP which will be used for pure N2, nitrogen mixtures and lean gases. The developed correlation yields the least error and is a function of average critical temperature of the injection gas, reservoir temperature, C7 + fraction molecular weight of crude oil, volatile components (mole fraction) and intermediate components (mole fraction) of crude oil. Since N2 is not as good a solvent for oils as carbon dioxide (CO2), or even methane (CH4), the pressure required for nitrogen to become miscible with any oil should be greater than that for methane which, in turn, is higher than CO2 . This especially makes nitrogen attractive for highly undersaturated reservoirs at immiscible conditions. Literature review on challenges in gas flooding and a solution The major technical challenge of immiscible gas injection is to maintain proper sweep efficiency of the injected gas, improve gas utilization and delay its breakthrough. These result from a combination of gravity override and gas channeling through high permeability streaks in the formation. Gas segregation, channeling and fingering through high permeability streaks are inherent in any gas injection; they are due to the excessively higher mobility and far lower density of gas (displacing phase) compared to oil or water (displaced phase). Unfavorable mobility ratios lead to even more severe channeling in heterogeneous reservoirs and heavier oil reservoirs. Consequently, the drive fluid does not contact a large part of the reservoir and the volumetric sweep efficiency of the reservoir remains poor . Furthermore, a displacement is adversely affected by capillary end effects, arising from the discontinuity of capillarity in the wetting phase at the outlet end of the core, that, for the gas/oil system, cannot be overcome by high gas throughput rates. WAG injection is implemented to improve mobility ratio and sweep efficiency.

Narrative of the Life of Frederick Douglass - 1034 Words

When reading through the book Narrative of the Life of Frederick Douglass, written by Frederick Douglass, the reoccurring theme is about a slave and his slave-owner. When going into research, I came to the conclusion that the book accurately describes the relationships between a slave owner and his slaves. It also accurately describes how families between slaves are treated and formed. Slaves were perceived as property by slave owners. Those people were merely an item that slave owners saw as trash that they could do whatever they wanted to them and it was â€Å"justified†. If a slave owner dies, the remaining slaves get divided among strangers or people in the family based on the slave owner’s will. Douglass explains a time when his previous master passed away. He described the other slaves being treated as livestock and nervous due to not knowing how they will be divided up despite who is a part of whose family. If the slave owner happened to have a wife that was pure from the slave owning life style, the slave might be lucky to get taught how to read or write if they were too young to work in the fields and forced to work in the house. When slaves were young, winters were very harsh to most children due to only being allowed one shirt for the whole year. Being a young slave, you were usually taken from your mother around twelve months when you no longer needed her. If the children were too young, they were usually given to a caregiver. Douglass was separated from hisShow MoreRelatedNarrative Of The Life Of Frederick Douglass987 Words   |  4 PagesLife of Frederick In the â€Å"narrative of the life of Frederick Douglass an American slave written by himself† Frederick reveled to audience the time he was living as a slave and the moments of brutal treats for example psychological, emotional and physical abuses. He was suffering terrible moments during his 20 years as a slave in the twentieth century. In addition, he describes in his own words the strategies he used to escape from the slave holders and to be free. This story the â€Å"Narrative of theRead MoreNarrative Of The Life Of Frederick Douglass Essay1102 Words   |  5 PagesDate Narrative Of The Life Of Frederick Douglass Writing in the favor of black people has always remained controversial from the very beginning. Critics regard such writing as â€Å"a highly conventionalized genre† indicating that â€Å"its status as literature was long disputed but the literary merits of its most famous example such as Frederick Douglass s Narrative of the Life of Frederick Douglass†¦are widely recognized today.† (Ryan:537) Despite of such severe resistance, writers like Douglass have pennedRead MoreThe Narrative Of The Life Of Frederick Douglass1566 Words   |  7 PagesThe â€Å"Narratives of the Life of Frederick Douglass† is the story of Frederick Douglass’ life from the time he was born into slavery, to the time he escaped to freedom in the north. When Douglass wrote this book, slavery was still legal in a large portion of the United States. After Douglass’ escape to freedom and his continuation of his education, he became an abolitionist through his works of literatu re and speeches. In â€Å"The Blessings of Slavery†, by George Fitzhugh he states that southern slavesRead MoreNarrative Of The Life Of Frederick Douglass1257 Words   |  6 PagesBook Review By Mary Elizabeth Ralls Narrative of the life of Frederick Douglass: An autobiography written by Frederick Douglass Millennium publication, 1945edition 75 pages Frederick Douglass whose real name was Frederick Augustus Washington Bailey approximately birthdate is in1818, the month or day is not known, he died in 1895. He is one of the most famous advocates and the greatest leaders of anti-slavery in the past 200 or so years.Read MoreNarrative Of The Life Of Frederick Douglass Essay1498 Words   |  6 Pagessoutherners believed that one of the most essential means of life was slavery. In the novel, Narrative of The Life of Frederick Douglass, Douglass challenges and debunks the idea of slavery being a necessary part of the white lifestyle; many pro-slavery arguments consisted of religion justifying slavery, slaves being â€Å"easily manipulated†/ignorant, and slavery keeping the southern economy from disappearing (The Proslavery Argument). Frederick uses personal experiences and other tactics to expose theRead MoreNarrative Of The Life Of Frederick Douglass1730 Words   |  7 PagesOne of the most well-known slavery narratives wa s lived and written by Frederick Douglass, Narrative of the Life of Frederick Douglass. Frederick Douglass was a civil rights activist who was born into slavery on a plantation in eastern Maryland in February 1818. His exact birth date is unknown, he states in his narrative, â€Å"I have no accurate knowledge of my age, never having seen any authentic record containing it.†2 His birth name was Frederick Augustus Washington Bailey, which was given by hisRead MoreThe Narrative Of The Life Of Frederick Douglass1363 Words   |  6 Pages In The Narrative of the Life of Frederick Douglass, Frederick Douglass portrays the importance of education because of its influence in leveling the playing field between the races in the 1800s. Education and knowledge are themes that are heavily dwelled upon throughout the novel, inspiring the reader to see the full power of such important ideals and to take the full advantage of both at all times. Douglass gives the reader a new appreciat ion for education as he delivers his message regardingRead MoreNarrative Of The Life Of Frederick Douglass1255 Words   |  6 PagesFrederick Douglass, throughout Narrative of the Life of Frederick Douglass, uses religion to get many of his points across. In one way, religion plays a huge role in Douglass’ ability to become literate throughout the text. With the Bible and other Christian texts, Douglass is able to further his ability and the ability of others to read. This becomes important because as Douglass points out the slaveholders believe a literate slave is not a good slave. This union of literacy and religion show theRead MoreThe Narrative Life Of Frederick Douglass1583 Words   |  7 Pages‘The Narrative Life of Frederick Douglass’ is an autobiography of Frederick Douglass, the slave who escaped and became one of renowned social reformers of his time. The book is a collection of actual experiences of the author during his time in slavery and experienc es of fellow slaves. He describes brilliantly the oppressive conditions into which he was born, lived, as well as his struggles and triumphs. The author meant to make the reader comprehend life of the African Americans in slavery beforeRead MoreThe Narrative Of The Life Of Frederick Douglass939 Words   |  4 PagesRevolutionary Freedom In 1845, an African-American man named Frederick Douglass released a thought-provoking autobiography that would become a turning point in revolutionary change. The Narrative of the Life of Frederick Douglass was the first autobiography Douglass had written focusing on the real life struggles he has faced during his time spent in bondage. During his time, it was not common for an African-American to have the skills to read and write, and it was especially uncommon to publish