Addiction Wikipedia. Addiction is a brain disorder characterized by compulsive engagement in rewarding stimuli, despite adverse consequences. Despite the involvement of a number of psychosocial factors, a biological process  one which is induced by repeated exposure to an addictive stimulus  is the core pathology that drives the development and maintenance of an addiction. The two properties that characterize all addictive stimuli are that they are reinforcing i. Addiction is a disorder of the brains reward system which arises through transcriptional and epigenetic mechanisms and occurs over time from chronically high levels of exposure to an addictive stimulus e. Fos. B, a gene transcription factor, is a critical component and common factor in the development of virtually all forms of behavioral and drug addictions. Two decades of research into Fos. Bs role in addiction have demonstrated that addiction arises, and the associated compulsive behavior intensifies or attenuates, along with the overexpression of Fos. B in the D1 typemedium spiny neurons of the nucleus accumbens. Due to the causal relationship between Fos. B expression and addictions, it is used preclinically as an addiction biomarker. Fos. B expression in these neurons directly and positively regulates drug self administration and reward sensitization through positive reinforcement, while decreasing sensitivity to aversion. As described by two groups of researchers, addiction exacts an astoundingly high financial and human toll on individuals and society as a whole through the direct adverse effects of drugs, associated healthcare costs, long term complications e. Classic hallmarks of addiction include impaired control over substances or behavior, preoccupation with substance or behavior, and continued use despite consequences. Habits and patterns associated with addiction are typically characterized by immediate gratification short term reward, coupled with delayed deleterious effects long term costs. Examples of drug and behavioral addictions include alcoholism, amphetamine addiction, cocaine addiction, nicotine addiction, opiate addiction, food addiction, gambling addiction, and sexual addiction. The only behavioral addiction recognized by the DSM 5 is gambling addiction. The term addiction is misused frequently to refer to other compulsive behaviors or disorders, particularly dependence, in news media. An important distinction between drug addiction and dependence is that drug dependence is a disorder in which cessation of drug use results in an unpleasant state of withdrawal, which can lead to further drug use. Addiction is the compulsive use of a substance or performance of a behavior that is independent of withdrawal. NeuropsychologyeditThis section needs expansion. You can help by adding to it. February 2. Cognitive control and stimulus control, which is associated with operant and classical conditioning, represent opposite processes i. Cognitive control, and particularly inhibitory control over behavior, is impaired in both addiction and attention deficit hyperactivity disorder. Stimulus driven behavioral responses i. Stimulus control of behavioreditCognitive control of behavioreditBehavioral addictioneditThe term behavioral addiction correctly refers to a compulsion to engage in a natural reward which is a behavior that is inherently rewarding i. Preclinical evidence has demonstrated that marked increases in the expression of Fos. B through repetitive and excessive exposure to a natural reward induces the same behavioral effects and neuroplasticity as occurs in a drug addiction. Program Effects Etc Ion OfflineReviews of both clinical research in humans and preclinical studies involving Fos. B have identified compulsive sexual activity specifically, any form of sexual intercourse as an addiction i. Moreover, reward cross sensitization between amphetamine and sexual activity, a property in which exposure to one increases in the desire for both, has been shown to occur preclinically and clinically as a dopamine dysregulation syndrome 1. Fos. B expression is required for this cross sensitization effect, which intensifies with the level of Fos. B expression. 1. 12. Reviews of preclinical studies indicate that long term frequent and excessive consumption of high fat or sugar foods can produce an addiction food addiction. Gambling is a natural reward which is associated with compulsive behavior and for which clinical diagnostic manuals, namely the DSM 5, have identified diagnostic criteria for an addiction. There is evidence from functional neuroimaging that gambling activates the reward system and the mesolimbic pathway in particular. Similarly, shopping and playing videogames are associated with compulsive behaviors in humans and have also been shown to activate the mesolimbic pathway and other parts of the reward system. Based upon this evidence, gambling addiction, video game addiction and shopping addiction are classified accordingly. Risk factorseditThere are a range of genetic and environmental risk factors for developing an addiction that vary across the population. Roughly half of an individuals risk for developing an addiction is derived from genetics, while the other half is derived from the environment. However, even in individuals with a relatively low genetic loading, exposure to sufficiently high doses of an addictive drug for a long period of time e. In other words, anyone can become an addict under the right circumstances. Adolescence represents a period of unique vulnerability for developing addiction. Not only are adolescents more likely to initiate and maintain drug use, but once addicted they are more resistant to treatment and more liable to relapse. Statistics have shown that those who start to drink alcohol at a younger age are more likely to become dependent later on. About 3. 3 of the population tasted their first alcohol between the ages of 1. As for alcohol abuse or dependence, the numbers start off high with those who first drank before they were 1. For example, 1. 6 of alcoholics began drinking prior to turning 1. This percentage is even lower, at 2. Genetic factorseditIt has long been established that genetic factors along with social and psychological factors are contributors to addiction. A common theory along these lines is the self medication hypothesis. Epidemiological studies estimate that genetic factors account for 4. Lithumoontomi bmaehrensw dmlLhhtbeto 2 Safety Issues for LithiumIon Batteries Lithiumion batteries are widely used as a power source in portable electrical and. Ocean acidification is sometimes called climate changes equally evil twin, and for good reason its a significant and harmful consequence of. Boeing Radiation Effects Lab 1499 1 Single Event Effects in Avionics Presented to C17 Program December 16, 1998 Dr. Eugene Normand Chief Scientist, Boeing. Similar rates of heritability for other types of drug addiction have been indicated by other studies. Knestler hypothesized in 1. For example, altered levels of a normal protein due to environmental factors could then change the structure or functioning of specific brain neurons during development. These altered brain neurons could change the susceptibility of an individual to an initial drug use experience. In support of this hypothesis, animal studies have shown that environmental factors such as stress can affect an animals genotype. Overall, the data implicating specific genes in the development of drug addiction is mixed for most genes. ETC-Eos-Gerontius-MAIN.jpg' alt='Program Effects Etc Ion' title='Program Effects Etc Ion' />One reason for this may be that the case is due to a focus of current research on common variants. Many addiction studies focus on common variants with an allele frequency of greater than 5 in the general population, however when associated with disease, these only confer a small amount of additional risk with an odds ratio of 1. Program Effects Etc Ion 2000Boiler Feedwater Treatment Part II Water Treatment Fundamentals Technical Library. Home Technical Library. Contents. Removing impurities from boiler feedwater. Filtration. Coagulation and flocculation. Brush Painting Software here. Reaction of lime soda in softening process. Ion exchange. Deaeration of water. Combination of ion exchange and lime process. Reverse osmosis. Internal treatment of boiler feedwater. Blowdown. Corrosion in steam condensate system. Care of out of service boilers. Removing impurities from boiler feedwater. Feedwater is filtered to remove suspended matter and if the suspended solids are very fine, a flocculation step may be needed to enable effective filtration. The water is then subjected to other treatments to make it suitable for the boiler. Depending on the quality of water, it may be subjected to one or more treatments like chemical precipitation, lime soda softening, ion exchange, deaeration, and reverse osmosis. Filtration. Filtration is the essential first step before the chemical treatment and conditioning of the boiler feedwater. Filtration removes or minimizes all types of suspended solid impurities. If rust, sand silica etc. Even the condensate feedwater must be filtered before returning to the boiler. The boiler itself and the steam piping produce rust particles etc. Filtration is also necessary for any water treatment process to work properly. For example, softening resins get coated with suspended matter, loosing their effectiveness and capacity to regenerate. Reverse osmosis membranes get fouled up leading to reduced efficiency and shorter life. If the water is very dirty, sand filtration is first done followed by cartridge filtration. Coagulation and flocculation. Some times the suspended particles in water are so fine that even cartridge filters are unable to remove them. In such a situation, before cartridge filtration, the water is first treated with coagulants. Coagulation is charge neutralization of finely divided and colloidal impurities in water into masses that can be filtered. In addition, particles have negative electrical charges, which cause them to repel each other and resist adhering together. Coagulation, therefore, involves neutralizing the negative charges and providing a nucleus for the suspended particles to adhere to. Flocculation is the bridging together of coagulated particles. Types of coagulants. Iron and aluminum salts such as ferric sulfate, ferric chloride, aluminum sulfate alum, and sodium aluminate are the most common coagulants. Ferric and alumina ions each have three positive charges and therefore their effectiveness is related to their ability to react with the negatively charged colloidal particles. These coagulants form a floc in the water that serves like a net for collecting suspended matter. Polyelectrolytes, which are synthetic materials, have been developed for coagulation purposes. Daemon Tools Lite Windows 7 64 Bit on this page. These consist of long chain like molecules with positive charges. In some cases organic polymers and special types of clay are used in the coagulation process to serve as coagulant aids. These assist in coagulation by making the floc heavier. Chemical precipitation. Chemical precipitation is a process in which chemical added reacts with dissolved minerals in the water to produce a relatively insoluble reaction product. Precipitation methods are used in reducing dissolved hardness, alkalinity, and silica. The most common example is lime soda treatment. Reaction of lime and soda in softening process. Calcium hydroxide hydrated lime reacts with soluble calcium and magnesium carbonates to form insoluble precipitates. They form a sludge that can be removed by settling and filtration. Lime, therefore, can be used to reduce hardness present in the bicarbonate form temporary hardness as well as decrease the amount of bicarbonate alkalinity in water. Lime reacts with magnesium sulfate and chloride and precipitates magnesium hydroxide, but in this process soluble calcium sulfate and chlorides are formed. Lime is not effective in removing calcium sulfates and chlorides permanent hardness. Soda ash is used primarily to reduce non bicarbonate hardness permanent hardness. The calcium carbonate formed by the reaction precipitates as sludge and can be filtered out. The resulting sodium sulfate and chloride are highly soluble and non scale forming. Methods of lime soda softening. The older method of intermittent softening consists of mixing the chemicals with the water in a tank, allowing time for reaction and forming of sludge, and filtering and drawing off the clear water. The modern method of continuous lime soda softening involves use of compartmented tanks with provision for a proportioning chemicals continuously to the incoming water, b retention time for chemical reactions and sludge formation, and continuous draw off of softened water. Lime soda softening is classified as hot or cold, depending on the temperature of the water. Hot process softeners increase the rate of chemical reactions, increase silica reduction, and produce over all better quality water. Coagulants used in lime soda process. In the initial clarification process, coagulants are used to agglomerate fine suspended particles, which can then be filtered out. Likewise, in the softening process, coagulants speed up settling of sludge by 2. Sodium aluminate used as a coagulant in lime soda softening being alkaline, also contributes to the softening reactions, particularly in reducing magnesium. Proper uses of coagulants help remove silica in the softening process. Silica tends to be adsorbed on the floc produced by coagulation of sludge. Disadvantages of lime soda softening. The main disadvantage is that while hardness is reduced it is not completely removed. Variations in raw water composition and flow rate also make control of this method difficult since it involves adjusting the amounts of lime and soda ash being fed. Advantages of lime soda softening. The main advantage is that in reducing hardness, alkalinity, total dissolved solids, and silica are also reduced. Prior clarification of the water is not usually necessary with the lime soda process. Another advantage is that with continuous hot process softening some removal of oxygen and carbon dioxide can be achieved. Fuel savings can be realized with hot process softening because of solids reduction. This reduction decreases the conductivity of the feedwater, thereby decreasing blowdown and conserving heat. Ion Exchange. Minerals dissolved in water form electrically charged particles called ions. Calcium carbonate, for example, forms a calcium ion with positive charges a cation and a bicarbonate ion with negative charges an anion. Some synthetic and natural materials have the ability to remove mineral ions from water in exchange for others. For example, in passing water through a simple cation exchange softener all the calcium and magnesium ions are removed and replaced with sodium ions. Ion exchange resins usually are small porous beads that compose a bed several feet deep through which the water is passed. Types of ion exchange resins. Ion exchange resins are two types cation and anion. Cation exchange resins react only with positively charged ions like Ca2 and Mg2. Anion exchange resins react only with the negatively charged ions like bicarbonate HCO3 and sulfate SO4 2. Although there are many types of cation exchange resins, they usually operate on either a sodium or hydrogen cycle.