Tuesday, November 26, 2019
thebes essays
thebes essays n THE CITIZENS OF THEBES HAVE GATHERED IN PRAYER. n ODEIPUS HAS COME PERSONALLY TO HEAR THE CITIZENS ALTHOUGH HES FAMOUS. n OEDIPUS ASKS THE ELDEST PERSON TO SPEAK ON BEHALF OF THE PEOPLE.THE ELDER IS A PRIEST. n EVERYONE IS CONSERNED BECAUSE OF THE PLAGUE EFFECTING THEBES. n OEDIPUS HAS SAVED THE CITY FROM THE SPHINX AND THE ELDER ASKS FOR HIS HELP AGAIN. n OEDIPUS SHARES THEIR PAIN AND IS ALREADY AWARE OF THE SITUATION. n OEDIPUS HAS SENT CREON TO THE ORACLE TO FIND OUT HOW TO PROCEEDE. n CREON HAS IMPORTANT INFORMATION BUT SAYS THAT THEY SHOULD SPEAK IN PRIVATE. n OEDIPUS SAYS THAT SINCE THE INFORMATION EFFECTS EVERYONE THAT IT CAN BE SAID IN FRONT OF EVERYONE. n CREON SAYS THAT GOD WANTS THEM TO GET RID OF AN EVIL PRESCENCE IN THEBES. n OEDIPUSWNATS TO KNOW WHAT THE EVIL IS. n CREON SAYS THAT ITS A MURDER AND THEY SHOULD KILL OR EXILE HIM. n CREON SAYS THE FORMER KING LAIOS WAS MURDERD BY HIGHWAYMEN. Oedipus needs to exile or kill the murderer of Laios. It is believed that this in turn will rid Thebes of the plague. Oedipus states that if anyone in Thebes has any information regarding the murder to come forward, even if they fear the consquiences of not comming forward sooner , because nothing bad will happen to them. Oedipus goes on to say that if it is found out that this person did know and said nothing then nobody is to ever again speak to this person or allow them in to their home. He also puts a curse on them for ever. ...
Friday, November 22, 2019
The Components of an Intriguing Biography
The Components of an Intriguing Biography A biography is a story of a persons life, written by another author. The writer of a biography is called a biographer while the person written about is known as the subject or biographee. Biographies usually take the form of a narrative, proceeding chronologically through the stages of a persons life. American author Cynthia Ozick notes in her essay Justice (Again) to Edith Wharton that a good biography is like a novel, wherein it believes in the idea of a life as a triumphal or tragic story with a shape, a story that begins at birth, moves on to a middle part, and ends with the death of the protagonist. A biographical essay is a comparatively short work of nonfiction about certain aspects of a persons life. By necessity, this sort of essay is much more selective than a full-length biography, usually focusing only on key experiences and events in the subjects life. Between History and Fiction Perhaps because of this novel-like form, biographies fit squarely between written history and fiction, wherein the author often uses personal flairs and must invent details filling in the gaps of the story of a persons life that cant be gleaned from first-hand or available documentation like home movies, photographs, and written accounts. Some critics of the form argue it does a disservice to both history and fiction, going so far as to call them unwanted offspring, which has brought a great embarrassment to them both, as Michael Holroyd puts it in his book Works on Paper: The Craft of Biography and Autobiography. Nabokov even called biographers psycho-plagiarists, meaning that they steal the psychology of a person and transcribe it to the written form. Biographies are distinct from creative non-fiction such as memoir in that biographies are specifically about one persons full life story from birth to death while creative non-fiction is allowed to focus on a variety of subjects, or in the case of memoirs certain aspects of an individuals life. Writing a Biography For writers who want to pen another persons life story, there are a few ways to spot potential weaknesses, starting with making sure proper and ample research has been conducted  pulling resources such as newspaper clippings, other academic publications, and recovered documents and found footage.  First and foremost, it is the duty of biographers to avoid misrepresenting the subject as well as acknowledging the research sources they used. Writers should, therefore, avoid presenting a personal bias for or against the subject as being objective is key to conveying the persons life story in full detail. Perhaps because of this, John F. Parker observes in his essay Writing: Process to Product that some people find writing a biographical essay easier than writing an autobiographical essay. Often it takes less effort to write about others than to reveal ourselves. In other words, in order to tell the full story, even the bad decisions and scandals have to make the page in order to truly be authentic.
Thursday, November 21, 2019
Whole Body Scanner Term Paper Example | Topics and Well Written Essays - 1750 words
Whole Body Scanner - Term Paper Example This paper looks to discuss these new machines and their impact and repercussions. Whole Body Scanner Airplane passenger screening had not changed for a long time but the events that occurred on 11th of September 2001 caused a drastic change in the airplane security planning. In the past screening were more focused on passengers entering the lounges and so on with detectors specified to detect metallic objects and x-ray machines used to scan the items for carry-on purposes (Elias, 2010). After the terrorist attacks taking place from time to time and after the recent attack in the Russian airport there has been a growing need to improve security. The Transportation Security Administration (TSA) under the U.S Department of Homeland Security has had to face a number of barriers in order to make their screening process more effective. Airport traffic has been on the increase for a long time and screening processes make it cumbersome for the passengers. There also needs to be a balance be tween the needs of the passengers and the security. Scares continue to take place even now as with the happening on 25th December 2009 when a Nigerian man attempted to ignite an explosive device while on board a plane heading to Detroit (O’Connor & Schmitt, 2009). Airports across the world are looking towards new technology to help security staff catch suspicious people and detect object deemed illegal on flights now. The problems that arise out of these technological advancements in airports are many such as privacy concerns, health concerns and subjection of minors to the scanning. On the other hand such technology can prove helpful in foiling terrorist plans, so there needs to be a weighing of the harms and benefits. Imaging technology has been bought and installed in the various airports all across the United States. According to the TSA there are two types of imaging technology that is being used, the millimeter wave and the backscatter x-ray. As of now, according to the TSA, there are 486 of these imaging devices that are being used across 78 airports in the United States (Transportation Security Administration). The millimeter wave scanner is used to scan the whole body and is used in the detection of objects that may be concealed in or under a person’s clothing. The millimeter scanner is cylindrical in shape with panels which contain scanners in them that rotate around the individual and produces an image of the individual. The scanner emits radio waves that pass through an individuals clothing’s and then returns an image of what is beneath the clothes. The scanner comes back with a picture of the human body which is generally what the security personnel hope to see, however, if other items are seem on the scanner then this may well be a reason for unease. The scanner does not take up too much time to do its job. The millimeter scanner produces a 3D image of the person being scanned that can be rotated and zoomed if the need be. Th e other scanner in use is the backscatter scanner which is what passengers in the United States will see more often. This scanner consists of two boxes opposite to each other with enough space for a person to stand in between them. These boxes take x-rays of the person in a time of about twenty seconds. The electromagnetic waves that are being emitted by the boxes are absorbed by the body but if there are any foreign bodies present on the person then these will show on the scans. There are some concerns that the waves being emitted are a form of radiation and may be dangerous for a person. This scanner takes a 2D image of the scanned person (Cynthia, 2010). The use of
Tuesday, November 19, 2019
STRATEGIC MANAGEMENT Assignment Example | Topics and Well Written Essays - 4000 words
STRATEGIC MANAGEMENT - Assignment Example Tesco initially had a localized approach as they could perceive benefits in expanding in and around London. However, their policy since the beginning had been â€Å"Pile it high and sell it cheap†(ICMR, 2005) which adversely impacted their brand image. When Britain imposed the Retail Price Maintenance Act which prevented the retailers from selling goods below a minimum price, Tesco introduced trading stamps which were given to the customers which could be traded for cash or gifts. This was abolished in 1964 and then Tesco could offer competitive prices. Cost-leadership strategy In the early 1990s, the market condition being bad, Tesco faced difficulties such as low population growth, low food price inflation, matured and saturated supermarket sector in the UK, and strong competition from retailers such as Sainsbury, ASDA, and Safeway (Coriolis, 2004). The company’s profit margins were under pressure and it remained in 2nd position with Sainsbury leading in market share (ICMR, 2005). In saturated markets competitive rivalry increases and the profits diminish as the costs are high. This was when the British economy was hit by recession and Tesco was in trouble although competitors such as Sainsbury and Marks & Spencer’s announced record earnings. This was the period when Tesco changed its strategy and focused on increasing its market share by selling goods at prices much lower than its competitors. Their strategy was to grow bigger by increasing sales volume through lower prices: Source: Coriolis (2004). Tesco went in for a major image overhaul and closed down many of its stores and replaced many with bright and attractive stores (ICMR, 2005). They were focusing on the cost-leadership strategy. In fact, Tesco was the first to introduce the cut-price strategy which led to price war (Yoruk & Radosevic, 2000). According to Porter (1996) strategy rests on unique activities and to be sustainable the strategic position requires trade-off. They did acquire cost-leadership and became the leading retailer in the UK but cost-leadership comes with disadvantages (Porter, 1979). Very low cost can take loyal customers away and lead to a decrease in revenue which is exactly what Tesco suffered with. They also earned a bad reputation in the process, which is when they decided to diversify. Strategy can be formulated at three different levels – corporate level, business unit level and the
Saturday, November 16, 2019
Phstat Essay Example for Free
Phstat Essay For Excel 2000 through Excel 2003, Microsoft Office macro security level set to Medium (see Topic 3a â€Å"Configuring Excel 2000-2003 Security for PHStat2†). For Excel 2007, Trust Center Macro Settings set to Disable all macros with notification (recommended) or Enable all macros. See section 3a or 3b for more details. (There are no security settings in Excel 97 or the original, unpatched version of Excel 2000. ) Internet access (for downloading updates to Microsoft Excel, from www. microsoft. com, and PHStat2, from www. prenhall. com/phstat, as they become available), optional but recommended. Requirements for running the PHStat2 setup program: CD or DVD drive. Approximately 10 MB hard disk free space while running the setup program and 3 MB hard disk space after program setup. On some older systems, the Windows system files that may get replaced or added during the setup process will require up to 6 MB additional hard disk space. Windows user account with administrator or software-installing privileges (does not apply to Windows 98Se or ME). Student or faculty accounts used to login onto networked computers in academic settings typically do not have this privilege. F Test for Differences in Two Variances: Two-tailed test formula to determine whether to reject null hypothesis corrected. Z Test for Differences in Two Means: Upper-tail test formula to determine whether to reject null hypothesis corrected. Minor reformatting in selected worksheet and dialog box labels. Enhanced statistical procedures in version 2. 5: Chi-Square Test includes Marascuilo Procedure output option. Histogram Polygons Frequency distributions include percentage and cumulative percentage columns. Kruskal-Wallis Rank Test Worksheet redesigned to accommodate larger number of groups.
Thursday, November 14, 2019
The Character of Brutus in Julius Caesar Essay -- Julius Caesar Essays
The Character of Brutus in Julius Caesar       Brutus was a very important character in the play Julius Caesar written by William Shakespeare. He helped plan a plot against one of the most powerful people in Rome and killed the king to be. Brutus was well renowned for his deep thinking, his honor, and most importantly, his belief in stoicism.       Brutus's stoic qualities played a major role in his character. He trusted his wife Portia very much. In fact, he trusted her so much that he was even going to tell her about the plot against Caesar.           "You are my true and honorable wife,          As dear to me as are the ruddy drops          That visit my sad heart"          ( II, i, 289-290)  She cared very much for him. She was willing to slice her thigh open just to prove her loyalty and trustworthiness to her noble husband. He also cared very deeply about his wife and he loved her very dearly.           "O ye gods,          render me worthy of this noble wife!"          ( II, i, 303-304)  Because of his profound stoicism, Brutus did not seem to show his graditude much when Portia killed her self. He simply drank wine to get ride of the pain and told Cassius to never speak of his wife again.           "Lucius a bowl of wine!          I did not think you could have been so angry,          O Cassius, I am sick of many griefs.          Of your philosophy you make no use          If you give place to accidental evils.          No man bears sorrow better. Portia is dead.          Ha! Portia!          She is dead.          How 'scaped I killing whe... ...          ( I, ii, 79-90)  Brutus had thought very deeply about joining the conspiracy. He had stayed up all night brooding about it. He feared that Caesar was gaining too much power and that soon Caesar would become king. If Caesar became king Brutus's dreams of Rome's Democracy would be shattered.       In conclusion Brutus was a very well respected man in Rome. He helped restore Rome to its original Democratic system. He ended up killing himself at the end of the play because of all the pressure. He had said at the end when he killed himself that           "....Caesar, now be still.          I killed not thee with half so good a will."          ( V, v, 50-51)  Work Cited: Shakespeare, William. Julius Caesar. Ed. Alan Durband. London: Hutchinson & Co. Publishers Ltd., 1984. Â
Tuesday, November 12, 2019
Ballot or the Bullet
People would come from all over the country to Harlem, New York in the year 1964 to listen to Malcolm Little, better known as Malcolm X, give his speeches about having more civil rights for the black community. He claimed that they should try to spend money inside of their community to help it prosper and prevent it from becoming a slum or a ghetto. He compared their situation many times to when America was first starting and how they had to fight for their freedom from Britain.Malcolm X talked about Patrick Henry and how he said, â€Å"Give me liberty or give me death†and was saying that they need to stand up for what they want. He said that there can not be a revolution with blood shed but America is in a position right now where they can be involved in a â€Å"Bloodless revolution. †One thing that he repeated throughout his speech was that it would be the â€Å"ballot or the bullet†(Malcolm X). This meant that they would either get what they asked for or th ey would have to fight for it.In Malcolm X’s speech he addressed different rhetorical strategies to convey his message to the people of Harlem. One way the speaker attempted to sway his audience to feel the way that he did was by telling the people that he was educated about how the white people felt when they were suppressed by Britain. The white people of the time were being taxed without representation. He learned who Patrick Henry was and how he would rise up and say â€Å"Liberty or death†which is the equivalent to what Malcolm X’s slogan was, ballot or the bullet.He said that, the statement â€Å"Liberty or death†brought freedom to the white people in this country and that if they could do it, so could he and his supporters. He also talked about how he knew the new generations of black people in this country didn’t care how far the odds were against them; they wanted to fight for their rights to be equals to the white people of America. The y would ignore the odds altogether until they had succeeded in what they have come to do.Later, Malcolm uses emotion to get his message across to his audience when he talks about how America right now could be the only place to have ever had a bloodless revolution by simply succumbing to what the black population wanted and give them their civil rights. He said that usually you aren’t in a position where you love your enemy but here is a time where they love America but just would like to be treated as equals along with the rest of the population.Malcolm also said that Uncle Sam was the one that created this problem in the first place and going to his court expecting him to fix the problem would do absolutely nothing because he is the criminal and he is the one that needs to be fixed. A little bit later he talks about how Afro-American churches are being bombed, little girls getting murdered, and leaders of the black population getting shot in broad daylight. He asks why this isn’t being brought to the UN when these sorts of things that happen in other countries go directly to the UN. Then Malcolm says that it is their turn to take their case to the UN.He says that there he will have the support of all different ethnicities, including the 800 million Chinese people out there. Malcolm also talks about how Uncle Sam is able to stand up and represent himself as the leader of the free world when he is violating the human rights of over 22 million Afro-Americans. Malcolm used different methods to try to get his feelings across to his audience but they all were directed towards the same purpose; to try to get the civil rights of the black population in America at the time. This worked to a degree, it got people all riled up to fight for their civil rights.He first talked about how when America was first starting they didn’t like it when their civil rights were suppressed and that the Afro-Americans feel the same way they want their rights. Then Malcolm talks about how this revolution doesn’t have to include any death as long as America listens to the black communities requests. He purposes that it is time to go to the UN and have them help sort this out with the help of other countries. He sums up his whole speech in four words and those words are â€Å"ballot or the bullet†they will get what they want or they will fight for it.
Saturday, November 9, 2019
Using Waste Cooking Oil as Feedstock and Candida Antarctica
Production of Biodiesel by Enzymatic Transesterification: using Waste Cooking Oil as feedstock and Candida Antarctica Lipase B as Biocatalyst. CHAPTER 1 INTRODUCTON The high cost of bio-diesel, compared to petroleum-based diesel, is a major barrier to its commercialization. It has been reported that 60-90% of bio-diesel cost arises from the cost of the feedstock oil (C. C. Lai et al. , 2005). Studies showed the potential of waste-cooking oil (WCO) as a material for biodiesel production (Sulaiman Al-Zuhair, 2008).Therefore, the use of WCO should greatly reduce the cost of bio-diesel. In addition to the choice of lipase employed, factors which make the transesterification process feasible and ready for commercialization are: enzyme modification, the selection of feedstock and alcohol, use of common solvents, pretreatment of the lipase , alcohol to oil molar ratio, water activity/content and reaction temperature. Optimization of these parameters is necessary in order to reduce the cost of biodiesel production.Use of no/low cost waste materials such as the WCO will have double environmental benefits by reducing the environmental pollution potential of the wastes and producing an environmentally friendly fuel. In addition, production of bio-diesel from WCO is considered an important step in reducing and recycling waste. A fresh vegetable oil and its waste differ significantly in water and free fatty acids (FFAs) contents, which are around 2000 ppm and 10-15%, respectively (C. C. Lai et al. , 2005; Y. Zhang et al. , 2003). Because of this the traditional alkaline-catalyzed biodiesel production is unsuitable (Zhang et al. 2003). The use of the enzyme lipase as a biocatalyst for the transesterification reaction step in biodiesel production has been extensively investigated. Lipase is produced by all living organisms and can be used intracellularly or extracellularly. In order to design an economically and environmentally sustainable biodiesel production process, a prop er understanding of the factors affecting the process and their relative importance of enzyme-catalyzed biodiesel production is necessary. A general equation for transesterification (where group R is a fatty acid, R’ is the ength of the acyl acceptor and R†is the rest of the triglyercide molecule) is as follows: Methanol is the most popular alcohol used in the transesterification process because of its relatively cheaper price compared to other alcohols. When methanol is used in the process, the reaction is known as methanolysis as shown in the following equation: Lipases from microorganisms (bacterial and fungal) are the most used as biocatalysts in biotechnological applications and organic chemistry. Fungal – source lipases have been found to produce high yields of lipases compare to the animal and plants.Because their bulk production is easier, commercialization of microbial lipases and their involvement in enzymatic biodiesel production are more common than animal and plant ones (Hasan et al. , 2006;Akoh et al. , 2007; Antczak et al. , 2009). The lipase to be employed as the biocatalyst is Candida Antarctica lipase B (Novozyme CABL L), one of the most common fungal lipase used for the production of biodiesel (Vasudevan and Briggs, 2008). Lipases are capable of converting all the triglycerides derive from the feed stocks into their respective fatty acids methyl esters (FAMEs).They act on the ester bonds of carboxylic acids allowing them to carry out their primary reaction of hydrolyzing fats (Joseph et al. , 2008). Enzyme immobilization is an important approach that could be used as a tool to improve and optimize operation stability, activity and selectivity which allows the enzyme to study under harsher environmental condition and also provides their separation from the reaction mixture without filtration in case of packed bed reactor (Fernandez-Lafuente et al. , 1998; Bhushan et al. , 2009; Gao et al. 2006) and, hence, could lead to m ore favorable economical benefits. The cost of lipase makes up 90% of the total cost of enzymatic biodiesel production. A significant portion of that is associated with the use of expensive carrier or support materials (Dizge et al. , 2009a). Search for cheaper support materials has been ongoing in order to reduce the overall cost of enzymatic biodiesel production (Robles et al. , 2009). Thus it is important to immobilize lipase, to be able to recover and reuse it repeatedly ( D. S. Clark,1994;D.Cowan, 1996). Immobilization of lipase is the attachment of the enzyme onto a solid support or the confinement of the enzyme in a region of space (Jegannathan et al. , 2008). When proper strategy for the lipase immobilization technology is employed , it provides a number of important benefits including: (a)enzyme reuse, (b) easy of separation of product from enzyme and (c) the potential to run continuous processes via packed-bed reactors (Peilow and Misbah, 2001). Methods of immobilization i nclude chemical and physical means.Among these, the physical immobilization by way of entrapment is the most widely-used method, in which enzymes are entrapped within the sol-gel matrix prepared by hydrolysis and polycondensation of precursors (Ko Woon Lee, et al. 2010). Tetramethylorthosilicate (TMOS) is a widely used precursor for sol-gel immobilization of the enzyme. However, CALB is unstable and shows low catalytic efficiency in the reaction media contains high concentration of methanol and the lipase is also inhibited by the by-product of glycerol.To overcome this, an amphiphilic matrix is developed to immobilize the lipase ((Ko Woon Lee, et al. 2010). The use of solvent in the transesterification process is also considered. Solvents are used to protect the enzyme from denaturation by alcohol by increasing alcohol solubility (Kumari et al. , 2009). The solvent can also increase the solubility of glycerol which is beneficial since the byproduct can coat the enzyme and inhibit it s performance (Royon etal. , 2007 ).The use of a common solvent for the reactants and products not only reduces enzyme inhibition but also ensures a homogeneous reaction mixture, reduces the reaction mixture viscosity and stabilizes the immobilized enzyme (Ranganathan et al. , 2008;Fjerbaek et al. , 2009). This is beneficial because homogeneous reaction mixture decreases problems associated with a multiple phase reaction mixture and a reduced viscosity reduces mass transfer problems around the enzyme (Fjerbaek et al. , 2009). The use of solvents significantly increases the reaction rate in comparison to solvent free systems (Vasudevan and Briggs, 2008).Some study also showed that methanolysis conversion using Candida antarctica was increased when tert-butanol was added to the system (Royon et al. , 2007). This serve as the basis for the choice of tert-butyl to be the solvent use in the system, in order to reduce the inhibition cause of the use of a lower chain alcohol, in this case, the methanol. OBJECTIVES This study aims to produce economical source of feedstocks such as waste-cooking oil for the production of biodiesel and the use of enzyme Candida Antarctica Lipase B, to catalyze to transterification reaction.To be able to determine the yield biodiesel through Gas Chromatographic Analysis (Chrompack CP 9001, Holland). SIGNIFICANCE OF THE STUDY Oil is one of the most commonly reported types of water pollution, causing nearly a quarter of all pollution incidents. Careless disposal of oil into drainage systems, onto land or to watercourses is an offense. It can harm river birds, fish and other wildlife. Because of the way oil spreads, even a small quantity can cause a lot of harm.It is estimated that UK caterers produce between 50 – 90 million litres of waste cooking oil each year. If this is not disposed of correctly the effects of oil pollution on the environment could be quite devastating. According to the Environmental Protection Agency (EPA), esti mates that over 200 million gallons of used oil ends up in the trash, and poured into the water each year. This study aims to promote conventional and economic source for the production of biodiesel by using home waste material such as waste cooking oil.Thus, resolving high cost of biodiesel production making it commercially producible and reduce devastation of environment due to high consumption of crude oils from fossil sources. This study will be a significant endeavour in promoting the social needs and to resolve the high prices of the gasoline which is the major economical crisis face in the present society. The advantages of using lipases in biodiesel production are: (a) ability to work in very different media which include biphasic systems, monophasic system (in the presence of hydrophilic or hydrophobic (Am.J. Biochem. & Biotech. , 6 (2): 54-76, 2010), (b) they are robust and versatile enzymes that can be produce in bulk because of their extracellular nature in most producin g system, (c) many lipases show considerable activity to catalyze transesterification with long or branched chain alcohols, which can hardly be converted to fatty acid esters in the presence of conventional alkaline catalysts, (d) products and byproduct separation in downstream process are xtremely easier, (e) the immobilization of lipases on a carrier has facilitated the repeated use of enzymes after removal from the reaction mixture and when the lipase is in a packed bed reactor, no separation is necessary after transesterification and (f) higher thermostability and short-chain alcohol-tolerant capabilities of lipase make it very convenient for use in biodiesel production (Bacovsky et al. , 2007; Kato et al. , 2007; Robles et al. ,2009). SCOPE AND LIMITATION Like any method for enzymatic biodiesel production, the cost of the lipase to be used is one of great consideration .The limitations of using lipases in biodiesel production include (a) initial activity may be lost because of volume of the oil molecule (Marchetti et al. , 2008; Robles et al. , 2009), (b) the use of solvent does not guarantee the complete protection of enzyme from the inhibitory effect of low chain alcohol, methanol (c) Although lipase is not affected by the high content of FFAs in WCO, the high water content remains a problem (d) the lipase in the biodiesel production is limited on a specific feedstock to be used because of the regioselectivity of the enzyme lipase.CHAPTER 2 REVIEW OF RELATED LITERATURE Biodiesel has shown its ability tomeet the energy demand of the world in the transportation, agriculture, commercial and industrial sectors of the economy (Akoh et al. , 2007; Basha et al. , 2009; Shafiee and Topal, 2009; Robles et al. , 2009). The annual world consumption of diesel is approximately 934 million tons, of which Canada and the United States consume 2. 14 and 19. 06%, respectively (Marchetti et al. , 2008).As a green renewable and potentially unlimited, biodiesel has recently come out as the superlative alternative fuel which can be used in compression ignition engines with minor or no modifications (Xu and Wu, 2003; Vasudevan and Briggs, 2008; Robles et al. , 2009; Leung et al. , 2010). The concept of biofuel is not new. Rudolph Diesel was the first to use a vegetable oil (peanut oil) in a diesel engine in 1911 (Akoh et al. , 2007; Antczak et al. ,2009). The use of biofuels in place of conventional fuels would slow the rogression of global warming by reducing sulfur and carbon oxides and hydrocarbon emissions (Fjerbaek et al. , 2009). Because of economic benefits and more power output, biodiesel is often blended with diesel fuel in ratios of 2, 5 and 20% (Vasudevan and Briggs, 2008). The higher the ratio of biodiesel to diesel the lower the carbon dioxide emission (Fukuda et al. , 2001; Harding et al. , 2007). Using a mixture containing 20% biodiesel reduces carbon dioxide net emissions by 15. 66% (Fukuda et al. 2001) while using pure biodiesel makes t he net emission of carbon dioxide zero (Vasudevan and Briggs, 2008). The simplest and most efficient route for biodiesel production in large quantities, against less ecofriendly, costly and eventual low yield methods is transesterification. One of the classic organic reactions (transesterification) is the step wise reversible reactions of a triglyceride (fat/oil) with an alcohol to form esters and glycerol. Little excess of alcohol is used to shift the equilibrium towards the formation of esters.Transesterification using an alcohol is a sequence of three reversible consecutive steps. In the first step, triglycerides are converted to diglycerides. In thesecond step, diglycerides are converted to monoglycerides. In the third step, monoglycerides are converted to glycerin molecules (Freedman et al. , 1984; Noureddini and Zhu, 1997; Marchetti et al. , 2008). Each conversion step yields one FAAE molecule, giving a total of three FAAEs per triglyceride molecule as described by the followi ng equations (Murugesan et al. , 2009). 1. Conversion of triglycerides to diglycerides . Conversion of diglycerides to monoglycerides 3. Conversion of monoglycerides tto glycerin molecules In order for the transesterification reaction to be applicable for biodiesel production, the process must be accelerated by the use of catalyst which may be alkaline, acids or enzymes (Bacovsky et al. , 2007; Murugesan et al. ,2009; et al. , 2010). The catalyst employed directly effects the purity of the feedstock required, the reaction rate and the extent of post reaction processing needed (McNeff et al. , 2008). To speed up the reaction, heat is also applied.However, this process is very energy intensive and inefficient since FAAE yield below 350 °C is very low and temperatures above 400 °C degrade the ester bonds (Ranganathan et al. , 2008). Generally, the reaction mix is kept just above the boiling point of the alcohol (71-72 °C) to speed up the reaction. The variables known to affect th e reaction are: temperature, alcohol to oil molar ratio, catalyst concentration and mixing intensity (Marchetti et al. ,2007). Transesterification catalysts: The transesterification process is catalyzed by alkalis, acids or enzymes.However, the use of alkali catalysts is 100% in commercial sector. The most common alkaline catalysts are sodium hydroxide (NaOH) METHODOLOGY * LIPASE CABL ( Novozyme CABL L) can be purchased from Novozyme (Denmark). All other chemicals can be purchased from Sigma- Aldrich (St. Louis, MO, USA). Grown in the laboratory, Candida appears as large, round, white or cream (albicans is from Latin meaning ‘whitish') colonies with a yeasty odor on agar plates at room temperature. IMMOBILIZATION OF LIPASE Sol – gel immobilization in an amphiphilic matrix was shown in figure below; mL of CABL (8. 2 mg/ml) is to be placed in a 50-ml Falcon tube with 1-mL of 0. 2 M phosphate buffer (pH 7). As a catalyst, 50 microliter of 1M sodium fluoride is to be added and the mixture is to be shaken with a vortex mixer. Then, TMOS (2 mM) and the following hydrophobic alkylsilanes (8 mM) is added; methyltrimethoxysilanes (MTMS), ethyltrimethoxysilane (ETMS), propyltrimethoxysilanes (PTMS), and iso-butyltrimethoxysilane (iso-BTMS). Gelation is usually observed within a few minutes while a reaction vessel is gently shaken.Following complete polymerization for 12 hours in a closed Falcon tube, the gel was dried for 24 hours in an open Falcon tube. The gel is to washed with 10 mL of distilled water, 10 mL of 99. 8% iso-propanol, and 10 mL of 95% n-hexane respectively. The immobilized CALB is to be filtered using filter paper, dried at 30 for oC for 36 hours and then ground with mortar and pestle. The particles were sorted using 500 and 300 micrometer sieves and stored at 4 oC until use. ENZYME SOLUTION Immobilized P. cepacia lipase solution is prepare by adding 0. g of lipase to 1 ml of distilled water and soak in water for 30 minutes, prior to being used. This step is found experimentally essential to activate the enzymes. WASTE-COOKING OIL PREPARATION In order to ensure consistency, waste cooking oil is simulated from the commercially available palm oil by heating 1 L of palm oil on a hot plate (Stuart, U. K. ), set at its maximum heating power for two hours. The oil is then allowed to cool to room temperature and then 5 ml of water (around 5000 ppm) is to be added. The sample is shelved for two weeks before being used.Fresh WCO samples were prepared every two weeks. Bio-Diesel Production in tert-butyl Solvent System Using C. Antarctica Lipase The experiment will be conducted in a specially designed 150 ml capacity jacketed reactor cell. The cell will be kept on a magnetic stirrer (Velp Scientifica, Italy) to facilitate the agitation of the mixture. Water from a temperature controlled water bath (Grant Instruments, UK) circulated through the jacket and will be set to maintain the temperature of the reac tion media constant at 45 oC.The temperature used was that presented in the literature to be the optimum(M. M. Soumanou,et al, 2003; H. Fukuda,et al, 2001 ) and an agitation speed was chosen to provide suitable mixing without affecting the activity of the enzyme. In this part, the working volume at the beginning of each experiment was 50 ml, consisting of 5 g of WCO, different volumes of methanol, in the range of 0. 4 to 0. 8 ml (correspond to 0. 57 to 1. 14 molar equivalents of ester bonds in the triglyceride chain), and tert-butyl solution to make up the total volume.The cell is to be covered tightly throughout the progress of the experiments to prevent evaporation. After thermal equilibrium is ensured, 1 ml of enzyme solution containing 0. 4% g of C. Antarctica lipase per g oil is added to initiate the reaction. At suitable intervals, 1. 5 ml samples are withdrawn into a capped vial, immediately immersed in boiling water for at least 5 minutes to denature the enzyme and stop the reaction, and then send for analysis. The amounts of FAMEs in the samples are to be determine by using Gas Chromatograph (Chrompack CP 9001, Holland).
Thursday, November 7, 2019
The End of The Indie Gold Rush -- A guest post for Bookmachine
The End of The Indie Gold Rush A guest post for Bookmachine The End of The Indie Gold Rush? A guest post for Bookmachine I was invited to guest post for Bookmachine and decided to dig deeper in the point made by Kristine Kathryn Rush that we might be at the end of the indie gold rush, if there ever was one. Here’s to starting the year on a positive note!An ALCS survey in the UK last summer crystallised industry concerns about whether career authorship is a viable profession these days. The report painted a somewhat grim picture for professional and part-time authors alike–regardless of whether those authors publish traditionally or independently. (For a crash-course on the industry landscape, I recommend Kristine Kathryn Rush’s exhaustive report on â€Å"things indies learned in 2014†.)The question now is, has the indie â€Å"Gold Rush†passed? Is success finite, and has it been mined to depletion?I don’t believe so.In fact, I’m convinced we’ll see many more indie success stories over the next few years–maybe even more than the ones weâ €™ve witnessed so far. The â€Å"Gold Rush†ends when there is no more gold left, or no way to get to it. That’s not the case here. The problem today is that there are too many people who want to find it, and perhaps not enough of them willing to do the hard work it takes to strike it rich.Read the whole post over at Bookmachine!
Tuesday, November 5, 2019
Nickel Element Facts and Properties
Nickel Element Facts and Properties Atomic Number: 28 Symbol: Ni Atomic Weight: 58.6934 Discovery: Axel Cronstedt 1751 (Sweden) Electron Configuration: [Ar] 4s2 3d8 Word Origin: German Nickel: Satan or Old Nick, also, from kupfernickel: Old Nicks copper or Devils copper Isotopes: There are 31 known isotopes of nickel ranging from Ni-48 to Ni-78. There are five stable isotopes of nickel: Ni-58, Ni-60, Ni-61, Ni-62, and Ni-64. Properties: The melting point of nickel is 1453Â °C, the boiling point is 2732Â °C, specific gravity is 8.902 (25Â °C), with a valence of 0, 1, 2, or 3. Nickel is a silvery white metal that takes a high polish. Nickel is hard, ductile, malleable, and ferromagnetic. It is a fair conductor of heat and electricity. Nickel is a member of the iron-cobalt group of metals (transition elements). Exposure to nickel metal and soluble compounds should not exceed 1 mg/M3 (8 hour time-weighted average for a 40 hour week). Some nickel compounds (nickel carbonyl, nickel sulfide) are considered to be highly toxic or carcinogenic. Uses: Nickel is used primarily for the alloys it forms. It is used for making stainless steel and many other corrosion resistant alloys. Copper-nickel alloy tubing is used in desalination plants. Nickel is used in coinage and for armor plating. When added to glass, nickel gives a green color. Nickel plating is applied to other metals to provide a protective coating. Finely divided nickel is used as a catalyst for hydrogenating vegetable oils. Nickel is also used in ceramics, magnets, and batteries. Sources: Nickel is present in most meteorites. Its presence is often used to distinguish meteorites from other minerals. Iron meteorites (siderites) may contain iron alloyed with 5-20% nickel. Nickel is commercially obtained from pentlandite and pyrrhotite. Deposits of nickel ore are located in Ontario, Australian, Cuba, and Indonesia. Element Classification: Transition Metal Physical Data Density (g/cc): 8.902 Melting Point (K): 1726 Boiling Point (K): 3005 Appearance: Hard, malleable, silvery-white metal Atomic Radius (pm): 124 Atomic Volume (cc/mol): 6.6 Covalent Radius (pm): 115 Ionic Radius: 69 (2e) Specific Heat (20Â °C J/g mol): 0.443 Fusion Heat (kJ/mol): 17.61 Evaporation Heat (kJ/mol): 378.6 Debye Temperature (K): 375.00 Pauling Negativity Number: 1.91 First Ionizing Energy (kJ/mol): 736.2 Oxidation States: 3, 2, 0. The most common oxidation state is 2. Lattice Structure: Face-Centered Cubic Lattice Constant (Ã…): 3.520 CAS Registry Number: 7440-02-0 Nickel Trivia German miners seeking copper would occasionally come across a red ore with flecks of green. Believing they had found copper ore, they would mine it and take it in for smelting. They would then find the ore produced no copper. They named the ore kupfernickel, or Devils copper since the Devil switched out the useful metal to confound the miners.In the 1750s, Swedish chemist Axel Cronstedt found kupfernickel to contain arsenic and a previously unknown element. We know now that kupfernickel is nickel arsenide (NiAs).Nickel is ferromagnetic at room temperature.Nickel is believed to be the second most abundant element in the Earths core after iron.Nickel is a component of stainless steel.Nickel has an abundance of 85 parts per million in the Earths crust.Nickel has an abundance of 5.6 x 10-4 mg per liter of seawater.Most nickel produced today finds its way into alloys with other metals.Many people are allergic to nickel metal. Nickel was named the 2008 Contact Allergen of the Year by the A merican Contact Dermatitis Society. References Los Alamos National Laboratory (2001), Crescent Chemical Company (2001), Langes Handbook of Chemistry (1952), CRC Handbook of Chemistry Physics (18th Ed.) International Atomic Energy Agency ENSDF database (Oct 2010)
Sunday, November 3, 2019
Nuclear Energy and the Environment Article Example | Topics and Well Written Essays - 1000 words
Nuclear Energy and the Environment - Article Example It is worth mentioning that the government of the US, both at Federal and State levels, has formulated and implemented few regulations in order to protect the environment from the lethal consequences of nuclear energy production. The US had 104 commercial nuclear reactors located in different regions of the country, which supplies nearly 20% of its total electricity requirements. However, it cannot be denied that the radioactive emissions released during the process of nuclear energy production are indeed life-threatening, accompanied with water pollution and air pollution, often accounted for causing early aging and cancer like diseases. It other words, radioactive emissions seriously disrupt the overall balance of the ecosystem. The threat associated with the nuclear fission reaction, in terms of radioactive emissions has not been limited to the US only but has emerged as a serious problem across the globe. The recent incidents in Japan’s Fukushima Daiichi nuclear power plan t that occurred in March 2011, owing to the catastrophic earthquake and tsunami, have extensively raised questions regarding the environmental safety of nuclear plants. This particular occurrence in the Fukushima Daiichi nuclear power plant has underscored many of the safety arguments advocated against establishing a nuclear plant. It can be number of incidents where environment and lives of human beings were under severe threat due to the nuclear disaster before the accident of Fukushima Daiichi nuclear power plant occurred... However, it cannot be denied that the radioactive emissions released during the process of nuclear energy production are indeed life-threatening, accompanied with water pollution and air pollution, often accounted for causing early aging and cancer like diseases. It other words, radioactive emissions seriously disrupt the overall balance of eco-system2. The threat associated with the nuclear fission reaction, in terms of radioactive emissions has not been limited to the US only, but has emerged as a serious problem across the globe. The recent incidents in Japan’s Fukushima Daiichi nuclear power plant that occurred in March 2011, owing to the catastrophic earthquake and tsunami, have extensively raised questions regarding the environment safety of nuclear plants. This particular occurrence in the Fukushima Daiichi nuclear power plant has underscored many of the safety arguments advocated against establishing a nuclear plant3. It can be number of incidents where environment and lives of human beings were under severe threat due to the nuclear disaster, before the accident of Fukushima Daiichi nuclear power plant occurred. The US has also witnessed nuclear disaster over the last decades. Accordingly, it has been ascertained that the nuclear power plant have laid significant impacts on the nearby areas in the form of water pollution, air pollution and radioactive waste generation4. DIABLO CANYON POWER PLANT IN CALIFORNIA AND ENVIRONMENT Diablo Canyon Power Plant (DCPP) is a nuclear power plant located at Avila Beach in San Luis Obispo region of California in USA. This plant generates nuclear energy to meet the electricity demand for millions of customers. DCPP supplies nearly 9.3% of California’s
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