Biochemical Processes of Oil Degradation

Biochemical Processes of Oil Degradation 1. INTRODUCTION Surfactants are surface active compound that reduce the interfacial tension between two liquids, or that between a liquid and a solid. Surfactants are organic compound that contain both hydrophobic (head part of the surfactant) and hydrophilic (tail part of the surfactant) moieties. Thus surfactant contains both water insoluble i.e. water repellent group as well as water soluble i.e. water loving group. Biosurfactants are also surface active compound like chemical surfactants but unlike the chemical surfactant, biosurfactant are synthesized by microbes like bacteria, fungi and yeast. Biosurfactants comprise the properties of dropping surface tension, stabilizing emulsions, promoting foaming and are usually non-toxic and biodegradable. Recently interest in biosurfactant has increased because of its diversity, flexibility in operation, and more eco-friendly then chemical surfactant (BS Saharan et al ., 2011; Eduardo J. gudiËÅ"na et al ., 2011). Biochemical process es of oil degradation carried out by microbes involves several type of enzymatic reactions driven by oxygenase, dehydrogenase and hydroxylase (Hamamura N et al., 2008). These enzymes cause aliphatic and aromatic hydroxidation, oxidative deamination, hydrolysis and other biochemical transformation of original oil substance leading to formation of large number of intermediate degradation products. However, a major limitation of microbial degradation of crude oil is its hyydrophobicity. Biosurfactant produced by oil degrading bacteria facilitate the uptake of crude oil hydrocarbons by bacterial cells and also have low toxicity and high biodegradability (Batista SB et al. , 2006). So, crude oil degrading bacteria with the ability to produce biosurfactant is widely recommended for fast degradation of crude oil. (Kumar M et al., 2006). Furthermore possibility of their production on large scale, selectivity, performance under intense conditions and their future applications in environ mental fortification also these have been increasingly attracting the attention of the scientific and industrial community. These molecules have a potential to be used in a variety of industries like cosmetics, pharmaceuticals, humectants, food preservative and detergents (BS Saharan et al. , 2011). But the production of biosurfactant on industry level is still challenge because of using high costly synthetic media for microbial growth. Biosurfactants are classified on the basis of diversity in their structure and their microbial origin. They contain a hydrophilic group, that contain an acid, peptide cations, or anions, mono-, di- or polysaccharides and a hydrophobic group of unsaturated or saturated hydrocarbon chains or fatty acids. Biosurfactants produced by a variety of microorganisms mainly bacteria, fungi and yeasts are diverse in chemical composition and their nature and the amount depend on the type of microbes producing a particular biosurfactant. 1.1 Classification of Bio surfactant: Biosurfactants are classified in to two major group one is low molecular weight surface active agent call biosurfactant and high molecular weight substance called bio-emulsifier that is especially used as enhancement of emulsification of hydrocarbon. Further these two major group is divided in to six major group known as glycolipids, lipopolysaccharides, lipoproteins-lipopeptides, phospholipids, hydroxylated and cross linked fatty acids. (a) Glycolipids: Mostly biosurfactants are glycolipds. They are lipids with a carbohydrate attached. The connection is by means of either an ether or ester group. Among the glycolipids, the best known are rhamnolipids sophorolipids and trehalolipids.

Plea Bargaining Essay Example | Topics and Well Written Essays - 500 words

Plea Bargaining - Essay Example Sometimes evidence, prior history, wealth and family can lure someone in power to change the way they may feel about prosecution others. The prosecuting attorney is the one who would decide whether a plea bargain is suitable. This should not be the case. A prosecuting attorney can decide to let someone whom is convicted to accept a plea bargain. Sometimes the plea bargain is given to the wrong person. Plea bargaining should be abolished under certain circumstances. Crimes that are a felony offense should not be able to accept a plea bargain. If the charge is damaging enough to qualify as a felony, the charge should not be able to be lessened. Those who are guilty of a certain crime should be held responsible for the crime committed. To give an example of why plea bargaining should be abolished in some cases is important. If a man in convicted of a felony rape charge, the charge can put the man in jail. In jail he will be forced to serve time for a crime that he committed. While in ja il, he can no longer hurt anyone else. If the man is offered a plea bargain and this plea bargain will keep him out of jail, he will be free to be out on the streets again. In this case, he may commit another crime. This can allow taking another victim. It is easy to see how this could have been avoided. On the other hand, there is a good side to offering a plea bargain.

1-Pilot & Non-pilot Protection of Transmission Lines Essay

1-Pilot & Non-pilot Protection of Transmission Lines - Essay Example This is of course in addition to today’s independent systems. It is important to note that the emphasis in this paper is not on the pilot scheme to be used but rather on whether a pilot system would be necessary. This follows the realization that a typical pilot terminal would cost $150K more compared with a non-pilot terminal. The question in this case is why would someone spend so much on a pilot scheme rather than just take up a non-pilot system which is less costly? The answers to this question serve as the justifications for the pilot scheme. Taylor (1927) says that the pilot scheme come in with additional benefits such as improved resistive coverage, high speed reclosing, and improved sustainability compared with the non-pilot system. In addition, the pilot scheme comes with alternatives to protection including fall back strategies, extensions to Zone 1, and inverse time over current. The pilot system also provides extended considerations mainly used in the determination of the system’s redundancy usually dependent on a number of factors including security, reliability, and dependability. The pilot system is also preferred because of its free interactions with the regulatory issues (Taylor, 1927). The protection of a transmission line has been a unique concept in the sense that, the system’s zone limit will have to separate geographical locations. This is contrary to the concepts in other systems such as buses, capacitors, and transformers. The idea behind the transmission line protection system is the alignment of the system elements and the input devices in one location and provides room for the instantaneous configuration of tripping. With the pilot scheme, this is usually done with very little coordination problems (Kim, 1996). Following the alignment of the system elements and input sources, all terminals will be