Subject is American Government. Topic is Socialization Essay

Subject is American Government. Topic is Socialization - Essay Example The strength of the political culture of a country depends on the extent at which these agents of socialization can help to teach the people about certain societal rules, values and expectations (Anderson & Taylor, 2007). Generally, the masses tend to follow the agent of socialization that inspires them politically (Brinkerhoff, White & Ortega, 2007). The mass media for example helps to disseminate information about the things that go on in the political mainstream of the country and it is what they give to the people that the people take. Thus, agents of socialization play a great role in shaping an individual’s political culture. The agent of socialization that has had the greatest influence in shaping my views about the government is the family. The reason is not far-fetched. They say charity begins at home and my perception about the government actually begins with the opinion of my immediate family. This is due to the fact that, my family is the closest agent of socialization to me and I hear their views and opinion about the government through our dinner talks and general discussions at home. Thus, any opinion that I have formed about the government could easily be traced to the discussions and debates I have had with my family. My parents have had a major influence in my perception of the government and this shows the extent at which, the family as an agent of socialization has had the greatest influence in shaping my perception about

International relatins - violence, resistance and identity Essay

International relatins - violence, resistance and identity - Essay Example The list of these countries underscores the fact that not only was Occupy Movement an international occurrence, but a movement that took place in democracies and capitalist states, also. The context in which Occupy Movement took place has both anteceding and triggering factors. The anteceding factors to Occupy Movement had been the longstanding culture of unfair power relations in the society and economic structures, the (mis)management of large corporations, multinationals and the entire international system to the point of inordinately benefiting only a minority, undermining democracy and precipitating an absence of financial and social security. Unknown to the casual observer, the triggering factor to Occupy Movement must have been the 2010 Arab Spring and the 2011-2012 Spanish Protests. No sooner had the two protests began in earnest than social online networks started going viral with calls to the effect that America and Britain needed their own Tahrir Squares. It is not in doub t that advancements in IT and liberalisation of information played instrumental roles in sparking Occupy Movement. The stated goals and aims of the Occupy Movement have slight discrepancies since there are country-specific demands that were put across. Nevertheless, it is clear that certain demands cut across all Occupy Movement protests throughout the globe. The goals included the addressing of the corrupting effects that money had on politics, the streamlining of regulations in the banking industry, the implementation of banking reforms, attainment of equality in income distribution, the proscription of high-frequency trading, the abatement of the influences that corporations have on politics, creation of better and more jobs, and the opening and successful completion of investigations and prosecution of those who propagate corruption in politics. (b) The Issue(s) at Stake There are several issues that emanated from the rise of Occupy Movement. One of the issues was the feasibilit y of capitalism and the neoliberal approaches to economics which capitalist persuasions brought about. The crux of the matter herein is that all the countries in which Occupy Movement took place are capitalist and thus adopted socioeconomic and political neo-liberalism. While the UK, America and the West branded capitalism as the pathway to success, 2 decades after the Fall of Communism (or communist USSR), Occupy Movement emerges to decry the ravages that are apparently associated with capitalism. The radical nature of the problem at hand is that, in the event that capitalism and neo-liberalism are found to be inchoate, the most tenable alternative system of production must be considered. Another matter that is at stake in this discussion is the extent to which the UK, America and the rest of the Occupy Movement countries can be said to be democratic. From December 2010, Occupy Movement countries had been cheering on the Arab Spring as a manifestation of a democratic reawakening. T he same countries had piled pressure on the regimes in the Arab world to concede to the demands of the hoi polloi. Thus, the manner in which Occupy Movement regimes responded to the protests and the success of the movements may serve as the litmus tests for

Recommendation for reducing substance dependence disorder from Essay

Recommendation for reducing substance dependence disorder from alcoholism - Essay Example Last year, there were 500 new cases of substance abuse mental disorder related to excess regular alcohol consumption. In this report, I give an explanation on better solutions identified by the state welfare committee and present our findings after comparison of substance abuse mental disorder cases in the state. Together with the social welfare committee, we have considered the following solutions: - law enforcement on bar attendants and the owners who sell alcohol to drunken patrons and extending drinking time limits. - increase the punishment of drunkenness and violation of regulations, which controls the selling and alcohol drinking - Social workers to create forums to educate the public on dangers of excessive alcohol drinking. There has been a big increase of substance mental disorder cases over the past couple of years. Excessive drinking of alcohol has been one of the major causes. This increase is attributed to ignorance, violation of rules controlling sale and drinking of alcohol not having effective public sensitization programs on dangers of abusing alcohol and lineament punishment to the offenders. Substance abuse disorder statistics compared The following statistics represents the total cases of diagnosed substance abuse mental disorder in 2010 and 2012 the percentage of the diagnosed cases related to alcoholism (Newton 183). The enforcement of laws that govern alcohol sale and consumption is a major step. This can be enhanced by employing more officers and giving them relevant patrol facilities. This will deter the law breakers from going against the regulations that control alcohol sale and consumption.

Hemorrhoids Research Paper Example | Topics and Well Written Essays - 500 words

Hemorrhoids - Research Paper Example Hemorrhoids are actually very simple to develop, which is due in part to the fact that hemorrhoids already exist in the body. All it takes to disrupt them is an increase of pressure in the lower rectum. Aspects that can cause increased pressure are straining during bowel movements, sitting on the toilet for long periods of time and chronic diarrhea. Other factors include obesity, pregnancy and anal intercourse. It is also possible to inherit the ability to develop hemorrhoids, as well as the possibility of developing them simply due to age. Signs and symptoms connected to hemorrhoids are painless bleeding during bowel movements, itching in or around the anal region, and swelling or painful lumps around the anus (Salinitri, pg. 16). Other symptoms include hemorrhoids jutting out from the anus that are very painful. The types of symptoms that an individual experiences is based entirely on where the hemorrhoids are, whether internal or external. When hemorrhoids are on the inside of the body, they are harder to feel, do not cause pain and often go unnoticed unless they start to bleed. Numerous options are available for treatment of hemorrhoids. Unfortunately, there is no cure for hemorrhoids, though there are plenty of methods to help alleviate the pain. Once a person develops hemorrhoids, and even after they have disappeared, it still remains in their body, capable of reappearing in the future. For more mild symptoms, over-the-counter creams and suppositories can be used. Their main purpose is to help relieve the pain caused by the hemorrhoids. For more painful symptoms, a doctor can prescribe other medications. There are other options to help with the treatment of hemorrhoids, such as rubber band ligation, which is when the doctor places rubber bands are an internal hemorrhoid to cut off its circulation (Kelsey, pg. 43). Injections are also available to help shrink the hemorrhoids, though this is not as effective as rubber band ligations. With

Motivation Project Essay Example for Free

Motivation Project Essay The drive to achieve goals is being motivated. Motivational theories are the processes to reach those goals. Being a new student in Caitlin’s situation is difficult. Catlin seems like she could be doing better. She isn’t pushing herself to her fullest. She lacks the desire to. Caitlin lacks a few of the things required for self-actualization; per her situation she is in she lacks a lot of motivation. She needs to find something worth achieving the grade for. She hasn’t achieved all the spots on Maslow’s hierarchy of needs; achievement motivation and neither intrinsic nor extrinsic motivation apply. Caitlin seems to have only hit a few points on Maslow’s hierarchy of needs chart. She lacks self-actualization, esteem and love/belonging. She doesn’t seem to know herself. She seems to be distracted given her situation. Physiological and safety she appears to have. She has to have physiological and safety she seems to have achieved. She lacks three out of five levels on the hierarchy of needs given her current situation. She lacks achievement motivation. There is nothing motivating her to achieve her goals in her world history class. Her life situation has her down regarding everything It is causing her to be distracted and she doesn’t have a way to be motivated to achieve her goals. She isn’t intrinsic motivated because she doesn’t seem to realize that there is a reason to achieve better than a c. She also doesn’t have extrinsic motivation because she is living a rough life. She doesn’t feel like she can achieve anything better. There is nothing either outside or inside of her that could push her to do better at his moment. I would say try and help her. Caitlin needs a friend. She is living in the next to impossible situation no that no one going to school wants to live. She is a new student and her parents are divorced. Her world has exploded for the average school age girl. She needs to know that she can trust you as her teacher. She needs to feel that you’re there and willing to help her with her both outside and inside academic issues. If she knows you’re willing to help with both then maybe she’ll better motivated to achieve higher grades. She needs a friend. Everybody needs to know they can trust their teacher. A healthy learning environment is the best thing that could be created for children.

Industrial Analysis For The Candy Store Marketing Essay

Industrial Analysis For The Candy Store Marketing Essay Our business plan is to design an on campus candy store which provides a wide range of candies to students and the staff at a cheaper rate. We hope to provide a new sweet experience to our customers to sweeten their most memorable days with our candies. To the students who like sweets our store will be a paradise of candies. And we will ensure the 100% customer satisfaction. Our mission statement. Our mission is to introduce a new era in the sweet industry by innovating new products, to give a totally different experience to our customers who step on to our store and to inject freshness in the sweet industry such as candies with different flavours, wide range of party packages, seasonal offers and many more. Market forecast Sales value of sweets were slightly in pace between 2005 and 2006 but sales has being increased because of gum and jellies. Sources suggests that the sugar confectionery market will increase by 9% at current prices over the 2007-12 period, rising to an estimated  £1.3 billion by 2012. C:UsersSubnet1Desktopid=273283name=figure6-1-1185370514.jpgmaxWidth=851maxHeight=450.jpg Sales of sugar confectionery in the UK have followed a modest upward trend over the review period. Some industry commentators estimate even flatter trends and a minor growth of 3-3.5% between 2005-2007. Health concerns as well affected for the sales growth because more concern about balance diets. The sugar confectionery market will increase by 9% at current prices over the 2007-12 periods, rising to an estimated  £1.3 billion by 2012. However, removing the effects of inflation reveals a much more growth equating to just 1% in real-terms. The market increasing at a similar rate to that seen over the 2002-07 period, growing 6% over the next five years. With volume growth behind value in current terms, this is indicative of a rise in spend per unit on sugar confectionery over the forecast period. SWOT analysis Following are the strengths and opportunities of our business which we possess to bring a better range of candies to satisfy the customers we will minimize our weaknesses and threats while finding solutions to overcome them. Strengths are, The logo which speaks to the customer and attract them. Especially youngsters will be keener on the logo. Main concern will be on more natural colours and flavours will help to attract more customers. Since consumers are focus on health, gum and jellies have taken more priority as they made up of natural fruit juices. Novelty products such as party bags, seasonal products and surprise gifts help to drag more customers as well customized range of party packages. Attractive price range so that everyone willing to buy. Strong management team to organize plans for future and for past. As well developing good skills, sales strategies to attract more customers and also to maintain good faith with the retailers. Weaknesses are, Higher innovation cost has to occur to invent new candies to attract the customers. Efficiency is less as incapable of paying higher salary to staff. Less exposure to the wider market to attract more customers. Opportunities can be, Young generation looking for more diverse product range. On campus is a good location as there are no specific candy shops which provide variety of candies. Event coverage with discounted packages. Even in higher economic crisiss people will are willing to buy candies. Threats can be, Competition with other supermarkets which are based on campus. Economic slowdown. Price wars. Trend for discounts. Higher labour cost. PEST control analysis Political: The government would have to collect taxes from the shop therefore the candy store would have to pay the normal tax rates. The business doesnt need to be privatised because the property that they are going to use is in Brunel University. They have to follow the health and safety regulation due to being in the packed food industry. The business would not have control on the spending of the public funds however since they would pay tax they would want to know where the government is using the tax that they pay. Economical: The store will be less likely to be affected with the interest and inflation rate because the products are not very expensive therefore there would be minimal effect on the sales of the shop. If the store keeps the service friendly, helpful and has policies to deal with situations like sales return these factors would help create consumer confidence. The rate of unemployment would affect the business due to the reason that the people would be less likely to spend their disposable income on things like candy therefore they should develop a strategy that would help them keep going at the time of recession. The labour cost would be how much money they would spend on recruitment and the recruitment process. Socio- culture: the trend, consumers taste and preferences, change in lifestyle would affect the store the occupation wouldnt matter because all age groups would have it. Mainly it is targeted to the students and staff of the university. Also including things like organic candy that would also be ethnic and healthy to would attract many consumers. Technological: there would be a balanced effect of this factor on the business. They need software that would help them to innovate thing for the business so that they can maintain their consumers however they may also use it to increase the number of consumers for the business. The business can discover something new or improve the way they serve the consumers. If they have any way of doing the accounts and also to keep track on the financial side of the business. Legal: the business would need to follow all the employment laws and company laws. The business would need to find out what are the regulations of the business their type they may do this by going to the food department of the location where they are going to start and find out what sort of licence is needed to start up the store the business would also need to get employees identification number, resale permit and a food handler permit. Environmental: the store will not be affected a lot with the climatic changes because you can have candy anytime. The business may make more profits around Halloween and Christmas however it may remain popular throughout the season. Water resources wouldnt affect the business because the business wouldnt need water to serve the consumers however they would need it to remain hygienic however they may also use anti-bacterial gels. Energy supply would affect the business because they would not be able to use the computers, they may use the fridge that keeps the stock of the candy at a certain temperature if the electricity is not there that might differ the taste of the candy. Porters five forces The threats of new entrants Usually there will be more threats to a candy store as it can be initiate with lesser amount capital, can start up as a home industry, no investors needed etc. But since our candy store located on campus there will be less threats of new entrants so the competition will be low. The buyer power The consumers will compare the prices of other candy stores with us, and choose which one they can get more benefit and which one is cheaper, which one is delicious, in this case, we maybe reduce the price then get less profit or enhance the quality of candy then more and more consumers like our candy. So it can be stated that buyer power is high since the students and willing to buy a candy as a snack after a lecture. The supplier power In production of candies the primary raw materials we need are the coco beans, milk, sugar etc. When finding manufacturers, there are many but it is more important to find one which has quality products at a reasonable price. Sometimes the manufacturers may use financial techniques such as hedging in order to reduce the price impact of price rises on their own margins. However since the fine grade of coco production shows small part of world supply, the bargaining power of suppliers will increase. Overall it can say that suppliers power is high as we are buying raw materials from suppliers and preparing our sweets. The threat of substitution Some substitutes for a candy shop could be traditional chocolates, snacks and other confectionary products which customers used to satisfy their sweet tooth. So its clear that the candy industry should face numerous types of other substitutes such as peanut butter, yoghurts, ice creams, cookies etc. Therefore there is a good variety of substitutes available for the consumers which make the threat of substitution high. The competitive rivalry The intensity among rivalry among competitors in a business can lead to price wars, advertising battles, new product lines and high quality customer service. On campus our main rivalry party will be the supermarkets and shops which sell candies but as we selling variety of candies such as jaw breakers. Gummies, candy cane etc the competition will be less. So as we based on campus the competitors threat will be less to our candy store. SWOT analysis for our competitors Strengths Firms brand name and resources. Experience of being in the industry for longer time. Highly skilled labour. Weaknesses Low product awareness. Lack of variety of candies. Poor facility location. Lack of innovations. Opportunities Easy access to market. Even in inflationary situations people will tend to buy the candies. Special seasoning offers. Threats Since it is easy to start up more competitors will be there. As customers are more health conscious it will affect the sales volume. Imposing new regulations by government towards the sweet industry. Market segmentation Geography Segmentation strategy will allow the company to determine whether the segment is large enough to sustain the product or if there is no viable market for the product. If the company decides that the strategy is a viable one, than the company can implement and design a marketing mix strategy to implement for each of their individual segments. The candy shop we are going to open will be on campus in which our target customers will be mainly the students and the staff. The first task important to our candy shop is to understand the relationship between consumers and products in order to understand the environment and those involved in the consumer process. Once we evaluates the environment then must investigate the segmentation bases. Our segment will be students and the staff to whom we will be bound to serve according to their preferences like what candies they like most, what flavours they need etc. Determining the segmentation of the marketing process identifies useful categories in specific segments in which to target. Soft confectionery: the sweet of choice NPD and advertising support have helped drive sales of soft confectionery, which exceeded  £700 million in 2011. This segment represents just under half of the total market, with steady growth expected to continue in the coming years. Consumer tastes appear to be shifting from traditional hard to soft confectionery as static sales of hard sweets have seen the segment lose market share despite a recent rise in NPD. Gum represents just under 20% of the total market, and although the segment posted growth in 2011, its share fell slightly due to the growth rate falling behind that of the overall market. Figure 30: UK retail value sales of sugar confectionery and gum, by type, 2009-11 2009 % 2010 % 2011 (est) % % change 2010-11 % change 2009-11  £m  £m  £m Soft confectionery 681 44 690 44 704 45 +2.0 +3.4 Mint confectionery 215 14 219 14 220 14 +0.5 +2.3 Hard confectionery 181 12 182 12 183 11 +0.5 +1.1 Functional confectionery* 130 8 128 8 129 8 +0.8 -0.8 Other confectionery 40 2 42 3 42 3 +0.0 +5.0 pricing strategy for the candy store: Our business would be using a combination of pricing strategy. We believe that Psychological pricing would help the consumers set a boundary and realise that the one pence makes a difference in the way they think about the price. for example when the price is  £10 pounds the consumer may not buy it but if it is written as  £9.99 then they may be attracted to it. We would also concentrate on the consumer based pricing because this may boost the sales of our shop and if the consumers find that we have a reasonable prices for our product of better promotional strategy. We think that the more offers we keep on the candies the more consumers we will get. This sort of pricing strategy can also sometimes keep us in line with our consumer because we will always know what sort of pricing most attracts them and do they think that our price for the candy is reasonable. We will also be using popular pricing: is when the shop would know how much are the consumers willing to pay for the product and then we will put an offer for example two bags of candy normally would cost  £10 but we would sell two bags less than  £9.50. Organisational structure: Organizational structure refers to the way that an organization arranges people and jobs so that its work can be performed and its goals can be met. When a work group is very small and face-to-face communication is frequent, formal structure may be unnecessary, but in a larger organization decisions have to be made about the delegation of various tasks. Thus, procedures are established that assign responsibilities for various functions. It is these decisions that determine the organizational structure. Candy store organisational structure: Director of marketing in candy store A marketing director is a person responsible for the overall marketing operations of an organization or business. The job requires not only having skill in the creative aspect of advertising, but also having the budgetary knowledge needed to plan appropriately. Thus, the marketing director must be an effective manager in terms of both budget, and the creative process. Time at the job will often be split between these two primary functions. In our candy store, there are two people manage advertising and budget. Our advertising should always be aesthetically pleasing so student will think happy thoughts when they think of candy. And use the Internet and traditional advertising to market your candy store, including writing your own press releases to disseminate to your local newspapers. Another idea is to visit local condominiums and leave samples and literature in the clubhouse, or take samples along with business cards to office buildings and give them to receptionists to hand out And budget our money so we have the resources to do what we want , for example: more advertising to attract student; more kinds of candy; more activity. Director of sales in candy store An individual employed by a business to manage the activities of subordinate salespeople, and to develop and implement an effective selling strategy for the business in general. The sales director typically has full control over the sales function and staff within the budget allocated by a business and is often part of its higher management. The director of our candy shop should presents a summary of his visits to the director of sales and marketing on a weekly basis prior and after the week is completed and conduct monthly competitor market survey on their new candy, promotion and pricing tactics and to report to director of sales for proactive strategic planning. Director of operations in candy store The manager of our candy store, who is responsible for the overall day-to-day operations. We divide our candy store to two parts, one of them is shop A, including zone A-D, and another one is shop B, including zone E-G, in this case, the student in campus can buy candy easily. Opportunities and treats There are many opportunities for new businesses to enter the sweet confectionary market. It is predicted that the sale figures of this market has increased by 9.6 percent in the UK. This is the only business that is not threatened by the inflation, because consumers still buy confectionary sweet even when they are on a tight budget. The graph below supports the statement. sugar sales 2006 to 2016.JPG Marketing strategy The market strategy for the company is to sell products that are organic, with no artificial flavours and colours. The business will also have an ethical approach towards their consumers and employees. The market offers the business to be potentially successful due to the consistent increase in the sales on sugar confectionary. It has grown so much that all of the supermarket must have an aisle where they dont sell sweets. As long as we keep our prices reasonable consumers are likely to be loyal and they would defiantly repurchase again and again. Figure 13:  Consumer Confidence Index,  monthly, January 2007-October 2011 C:UsersThe HarsMusicid=599844seq=11maxWidth=851maxHeight=450.jpeg

The Reactor Design Project Engineering Essay

The Reactor Design Project Engineering Essay The project objective was to optimize three different adiabatic ammonia reactor configurations with respect to reactor performance in order to produce 800 tonnes of ammonia per day, or the molar equivalent of 0.5447 kmol s-1 of ammonia. The optimizations in reactor performance involved primarily, minimizing the catalyst volume and secondarily, maximizing the catalyst lifespan, as well as ensuring the final operating conditions were stable. Due to the absence of a cost function, the reactor could NOT be optimized with respect to cost minimization. Three different reactor types were considered, namely a single plug-flow reactor, a dual interstage cooling reactor and a dual cold-shot cooling reactor. Temperature, pressure and fraction of ammonia in the feed stream were found to have the greatest effect on the resultant catalyst volume. Using MATLAB, it was found that the minimum volumes were 9.61 m3, 3.94 m3 and 4.78 m3 for a single stage plug-flow, an interstage cooling configuration and a cold shot cooling reactor configuration respectively. The interstage cooling reactor allowed for a 59% decrease in total catalyst volume when modified from the single stage design, but required an increase in inlet feed temperature of 115K and 2 additional heat exchangers. The cold shot cooling method allowed for a 50.2% decrease in reactor volume from the single stage design, requiring a 75K increase in feed temperature. 1. Introduction 1.1. Background Ammonia synthesis (also known as the Haber process) is one of the most widely applied chemical processes in the world; in 2009, the total worldwide production of ammonia exceeded 133,000 metric tonnes 1, this is second only to the worldwide production of sulphuric acid. Most of the ammonia produced is used in the manufacture of fertilisers (such as ammonium nitrate), ammonia is also used in the manufacture of nitrogen-based polymers such as nylon. Another noteworthy use of ammonia is as the starting reagent for the manufacture of nitrogen-based explosives such as nitroglycerin. The reaction which generates ammonia is exothermic and equilibrium limited: N2 + H2 is in equilibrium with NH3 ΆHR (298K, 1atm) = -46.11 kJmol-1 [Eqn. 1] In the early 20th century, Fritz Haber discovered that in order to obtain a significant yield of ammonia, the reaction required both high pressures and low temperatures (in accordance with the van t Hoff-Le Chatelier principle). It was known that the rate at which N2 decomposed in the reaction was very slow (N2 is thermodynamically more stable than NH3); therefore a very efficient catalyst was required in order to facilitate ammonia formation. Nowadays, the catalyst used in most industrial ammonia reactors is usually a porous form of enriched iron. Catalysts are expensive, but they present a good trade off; reactors are able to produce sufficient amounts of product at lower, more manageable temperatures and pressures. 1.2. Design objective The overall objective was to design a continuous fixed bed plug-flow process to meet the companys daily ammonia production demand of 800 tonnes per day (exclusive of any ammonia in the feed). The primary design objective was to try to minimize the catalyst volume the process required in order to meet the production requirement. The design also had to be considered safe to operate and had to operate at conditions that were considered to maximize the lifespan of the catalyst; these two were considered as secondary objectives. The preliminary design of the reactor considered a single-stage adiabatic bed with a bed cross-sectional area of 2.0 m2. The final designs involved two different two-stage systems; one implementing interstage cooling and the other implementing cold-shot cooling. Reactor performance and sensitivity were analysed by observing the effects of altering specific operating and design variables. The cost function for the process was not known, therefore it is important to note that the reactor could not be optimized with respect to cost, however the design could be implemented such that the reactor performance was greatly improved. For example, minimizing the required catalyst volume (and hence minimizing the reactor volume) will reduce the construction cost of the reactor. However this may come at the expense of greater operating and maintenance costs and, in the case of two-stage systems, may result in additional construction costs (interstage cooling requires heat exchanger(s) to be built). The investigation will only allow qualitative suggestions to be made as to which specific design aspects contribute to the generation and/or reduction of costs. 1.3 Safety The reactor operating conditions should be stable; such that small disturbances will not lead to thermal runaway (which has important implications for safety). Other than that, there are no large risks involved with operating the ammonia reactor, provided that good process control is implemented by the operator. 2. Kinetic theory and types of reactor configurations 2.1. The kinetics of ammonia synthesis and its implications on reactor design Ammonia synthesis involves a single exothermic, reversible reaction between nitrogen and hydrogen. For reversible reactions, the conversion corresponding to thermodynamic equilibrium at the chosen operating conditions cannot be surpassed. Since the reaction is exothermic, the activation energy (which is only temperature dependent) of the backwards reaction is greater than that of the forward reaction. Therefore an increase in temperature causes a rise in the rate of the reverse reaction which is greater than the rise in the rate of the forward reaction thus decreasing the maximum attainable conversion but decreasing the required catalyst volume. On the other hand, operating at a lower temperature increases the maximum attainable conversion, whilst reducing the total reaction rate and increasing the required catalyst volume. With regard to pressure, the effect is the opposite; increasing the pressure causes a greater rise in the rate of the forward reaction compared the backward react ion and vice versa. Designing a reactor producing ammonia therefore requires a compromise between keeping temperatures sufficiently high such that reaction rate remains significant whilst obtaining a respectable conversion of ammonia. Similarly, the pressure should be great enough so as to maintain a significant reaction rate, but not so high as to cause the reactor to deviate from safe operation. In order to minimize catalyst volume (and meet the primary objective), it is desirable to operate at the maximum forward rate of reaction at each cross-section across the reactor; thus maximizing the average forward rate across the reactor, this allows the desired extent to be met with the minimum catalyst surface area and hence with the minimum catalyst volume. In order for this to occur, each cross-section in the reactor must be operated at the unique pressure and temperature required to achieve maximum rate for a particular extent, i.e. the reactor moves along the locus of maximum reaction rates. This is unfeasible in this investigation since there is no temperature or pressure control implemented across the reactor (the reactor is adiabatic and WSHAFT=0); and even so, maintaining specific pressures and temperatures at each point along the reactor is practically unfeasible in itself; as each point in the reactor would require its own heat exchanger and pressure control system. Therefore for exothermic reversible reactions (without heat removal), the temperature increases along the length of the reactor and the rate vs extent profile will always have a characteristic maximum because the temperature along the reactor increases due to the heat released by the reaction, causing the net production rate to increase up to a certain extent before the reverse reaction starts to become significant. As the rate of the backwards reaction tends to increase further and temperature rises, the overall reaction rate will eventually reach zero at equilibrium. 2.2. Brief description of the Plug-Flow Reactor (PFR) A plug-flow reactor is characterized by fluid flowing through one end of the reactor and out the other, whilst satisfying the assumptions of plug-flow. The assumptions state: Fluid properties and flow rate remain constant across any cross-section of the reactor. The flow is orderly, with no element overtaking or mixing with fluid ahead or behind, (i.e. the residence time is the same for all fluid elements). The above assumptions tend to hold true where there is turbulent flow (Re >105), ensuring good radial mixing, and if the ratio of reactor length to diameter of the reactor is large (ratio à ¢Ã¢â‚¬ °Ã‚ ¥ 50), where lateral mixing may be neglected 2. Figure 1: An illustration of a plug-flow reactor 3 2.3. Brief description of Interstage Cooling Interstage cooling, also known as intercooling, is a multiple reactor design suitable for exothermic reversible reactions. Heat exchangers are used to cool the output of each reactor before being passed on to the next reactor, allowing for a greater possible conversion to be achieved in each successive reactor. This process can be replicated for an indefinite number of reactors until the reactor temperature is too low for reactions to occur or until the decrease in catalyst volume is not worth the additional cost of construction and complexity of operation. This project considers only the case where two reactors are used. Figure 2: An illustration of a dual reactor interstage cooling system4 2.4. Brief description of Cold-shot Cooling Cold-shot cooling reactor designs are similar to that of interstage cooling, but allow for elimination of the intermediate heat exchangers by injecting cold feed directly into the outlets of each reactor. This addition cools down the outlet stream of the reactor and also has the effect of decreasing the composition and conversion of the flow into the subsequent reactor (corresponding to the path from point b to c in Figure 3 below). Figure 3: An illustration of a dual reactor cold-shot cooling system 5 The flow diagram of two cold-shot reactors illustrates the lack of heat exchangers as compared to interstage cooling, as well as the splitting of the initial feed stream by the splitting fraction alpha, ÃŽÂ ±, which is the fraction of the fresh feed used as the coolant. The extent of reaction remains constant after mixing (which can be proven by a mass balance). 3. Mathematical model Derivations of differential equations All the assumptions of plug-flow mentioned above were applied in the construction of the equations below; the reactor was also assumed to operate at steady state (there is no mass hold up due to the catalyst). All other assumptions are mentioned in the derivations. It should be noted that rNH3 is defined as (rNH3 generated rNH3 consumed) and is measured per unit of catalyst volume; hence the equations specify the volume of catalyst VC and not the reactor volume VR. 3.1. Change in catalyst volume with respect to the extent of reaction: Mass balance on ammonia: [Eqn. 2] The extent of reaction can be defined as: [Eqn. 3] Equations 2 and 3 were combined to obtain the following equation: Since , the equation above was rearranged to give the initial catalyst volume gradient: [Eqn. 4] 3.3. Change in temperature with respect to the extent of reaction: Figure 4: An illustration of the cross section of a plug-flow reactor An energy balance across an infinitesimally small cross section of the catalyst bed gave: Shaft work (W), changes in kinetic energy and changes in potential energy were neglected: The equation above was divided by the cross-sectional area of the tube, A: where Q denotes the heat transfer by conduction. In the equation below, the enthalpy change upon mixing was neglected (a perfect solution was assumed). It was also assumed that the gases in question were ideal and hence their enthalpy was independent of pressure, the energy balance then took the form: [Eqn. 5] is the standard heat of formation of compound. i denotes each species present. Recalling that for a tubular reactor, and : does not have a negative sign as rproduct is calculated as the main subject) [Eqn. 6] The heat of reaction was simplified as shown below: [Eqn. 7] Equation 7 was substituted into Equation 6 which was then substituted into Equation 5: [Eqn. 8] The chain rule was used to combine and : Since the reactor was assumed to be adiabatic, Q = 0: [Eqn. 9] 3.4. Change in pressure with respect to the extent of reaction: The chain rule was used to find using the formula for , bed cross-sectional area A and since A dl = dVC. Substituting the components of the three terms above, we get the initial pressure against extent gradient formula: [Eqn. 10] 4. Simulation theory and strategy 4.1. Main simulation objectives Regardless of the design used, these objectives are overarching and apply to all three reactor types: The first two bullet-points define what is meant by optimizing the reactor: Minimizing catalyst volume; Operating temperatures and pressures are limited by safety considerations (preventing thermal runaway), material construction and catalyst degradation conditions. These degradation conditions are specified by actual limits set by ammonia process operators in industry: these are above 823 K and above 300 bar 6; Interstage and cold-shot cooling designs are only dual reactor designs. The derivation of the required total extent for all simulations is as follows: The MATLAB coding incorporating the required data and was used to solve the differential equations described earlier in the mathematical model for the outlet temperature, pressure and catalyst volume; all the assumptions applied in the mathematical model were thus applied in the coding, unit consistency was also maintained in the programming. 4.2. Single stage simulation strategy It is clear that a plug-flow reactor can take advantage of concentration profiles present in the reactor in order to minimize the total catalyst volume. Near the desired extent, adiabatic plug-flow reactors (running exothermic reversible reactions) operate ideally somewhere between the equilibrium line, where the rate of the forward and backwards reaction are equal, and the optimum line, which is a curve connecting the maximas of all the different rate curves, also known as the locus of maximum rates. Figure 5: A graph displaying the variation of forward rate with extent It is opted to run the reactor under conditions such that the inlet rate is exactly equal to the outlet rate where the reactor exits at the desired extent of 0.5447. The rin = rout condition limits the maximum average rate by a small amount but provides a greater amount of kinetic stability in the event of a disturbance; a small increase in the inlet temperature may push the reaction closer to equilibrium whilst a small decrease in the inlet temperature will decrease the outlet rate slightly but still allow the reactor to operate in a region of higher rates. The locus of rin = rout is found between the optimum line and the equilibrium line. As shown in Figure 5, this condition also means that the region of maximum reaction rate is taken advantage of; i.e. the rate in the reactor is always greater than or equal to the inlet rate. Therefore, although the temperature increases along the reactor, the forward rate is kept as high as possible. As the extent of reaction increases across the reactor for a fixed set of inlet conditions, it is expected for the surface area of catalyst to increase; if more product is generated, more catalyst is required to facilitate this generation. There is a limit in the MATLAB coding such that the catalyst volume decreases whilst the reaction extent continues to increase; the code is such that results after this point are treated as erroneous and are not used, thus the code finds the inlet conditions needed to achieve the maximum possible extent for an adiabatic reactor. To apply the simulation strategy, a MATLAB program was created to find the inlet conditions which satisfy the rin = rout condition for a desired final extent (0.5447 in this case). A separate program was also created to vary operating and design conditions individually and examine their effect on the catalyst volume. Graphs of the locus of maximum reaction rate, locus of rin = rout rates and the equilibrium curve were constructed using the desired inlet conditions determined from the single stage simulation. 4.3. Interstage cooling simulation strategy The overall reaction follows the adiabatic operating curve (it may not necessarily be a straight line due to the pressure drop across the reactor). It was desirable for the reaction to end at the same point as in the single stage simulation (with the same final extent); where the rate at the outlet of the second reactor lies on the rin = rout line for the desired extent. It was also desirable for the rate at the exit of the first reactor to be equal to the rate at the entrance of the second reactor; so that the reactor can continue onwards from the same rate in the second reactor (and maintain the average forward reaction rate). For this code, there was no condition that the rate at the inlet of the first reactor must equal the rate at the outlet of the first reactor (and likewise for the second reactor); since it was unfeasible to make the rates equivalent at all the inlets and outlets. Instead it was specified that rate1 OUT= rate2 IN and that rate2 OUT = rate OPTIMIZED SINGLE STAGE OUT. The extent in the first reactor (and therefore in the second reactor) had to be specified for each set of results. If the extent was too high, the outlet of the first reactor would be very near equilibrium whilst if it was set too low the outlet of the first reactor would be reached before the maximum rate had been obtained; therefore a degree of overshoot past the maximum reaction rate was desirable; the program ensured that there was a degree of overshoot past the maximum reaction rate in both reactors before validating a result. The locus of maximum reaction rates (from the single stage optimization) was used to determine the feed temperature for which the rate is a maximum at the start; this temperature was roughly 790K (located graphically). Above this temperature, the region of maximum reaction rates was not utilised at all; and the maximum extent achievable (using the gradient of the operating line) at equilibrium was roughly 0.28. This specified the minimum extent of reaction in reactor 1. If the feed temperature were too low, the first reactor would perform similar to a single PFR, defeating the purpose of having two reactors. Thus a moderate extent range of 0.3 0.4 was chosen for the first reactor as it was unworkable to put an excessive production load on either reactor. In order to apply this strategy, a program was used to specify the inlet conditions to the second reactor; the program moved along the operating curve using the initial conditions obtained in the single stage reactor up to the desired extent in the first reactor. This gave the inlet rate to the second reactor as well as the flow rate, temperature and composition of this stream. Following this, the rate1 OUT = rate2 IN condition was used to acquire the inlet and outlet temperatures and pressures of the first reactor and its volume. Lastly, the inlet conditions to the second reactor and the remaining extent were used to calculate the volume of the second reactor. The combined volumes and degrees of cooling between the reactors were compared for the chosen range of extents. 4.4. Cold-shot cooling simulation strategy Figure 6: A graph displaying the variation of extent with temperature for a cold-shot system The rate identity rin=rout used to optimize the single PFR was used in the cold-shot cooling reactor design. With reference to Figure 6, optimization was achieved by ensuring that the reaction moved from points aÆ’Â  bÆ’Â  cÆ’Â  d , with the following rate identities; ra = rb and re = rd. The second reactor would operate along the path that the optimum single PFR would operate on (e Æ’Â   d). By adhering to the above conditions, there were three variables left to define, namely alpha (ÃŽÂ ±), initial feed temperature Tini and the interstage extent ÃŽÂ ¾1. Fixing alpha and Tini would automatically define ÃŽÂ ¾1 and outlet temperature of the first reactor as the rates at points a and b must be the same. This optimized the first reactor for the given inlet conditions. By constructing enthalpy and mass balances on the mixing point of the outlet from the first reactor with the cold stream, the inlet temperature into the second reactor was determined, thereby finding outlet conditions of the second reactor, should it achieve the required extent of 0.5447 kmol s-1. Finally, in order to ensure that total optimization had occurred for the specified alpha and temperature, the difference in rates at points e and d was confirmed to be as close to zero as possible. Several iterations would be required to home in on the best inlet temperature for a given extent. The temperature of the feed used for cooling, Tf, was 298K; significantly lower than the temperature of the fluid exiting the reactor. This imposed an upper limit on the split fraction ÃŽÂ ±, beyond which the feed temperature into the second reactor would be too low for reactions to operate at an acceptable rate; catalyst volume would need to be larger to counter this effect, meaning optimization would not achieved. Therefore, by varying ÃŽÂ ± for 50 equal intervals from 0.01 to 0.5, and finding the 50 corresponding Tini values that satisfied the above stated rate identities gave the optimum reactor for each value of ÃŽÂ ±. The best cold-shot reactor specification was easily deduced from the setup which had the smallest overall catalyst volume. Results and Discussion 5.1. Single Plug-flow Reactor 5.1.1. Varying the ammonia composition in the feed Figure 7: A graph displaying the effect of ammonia feed mol % change on catalyst volume The composition of ammonia in the feed was changed while keeping the molar feed rate constant. (Change ratio: 4% decrease in NH3 = 1% increase in N2 + 3% increase in H2, etc). Figure 7 shows that decreasing the ammonia fraction from the original 8 mol % (while increasing the reactant mol %) lead to a significant drop in catalyst volume required. The greater concentration of reactants favoured the forward reaction, increasing the rate of formation of ammonia, leading to a smaller catalyst volume. When the ammonia fraction was too high (à ¢Ã¢â‚¬ °Ã‚ ¥0.16), the initial concentration of reactants was insufficient to achieve the required extent. Also, as the partial pressure of ammonia increased in the reactor, a greater proportion of the catalysts active sites became blocked and the forward rate decreased, increasing the required catalyst volume 7. It was decided to keep the mol % of ammonia in the feed at 8% in subsequent simulations; although the lowest mol % of ammonia in the feed produces the minimum catalyst volume, it is impractical for this to occur since ammonia is normally recycled in industrial reactors 8. 5.1.2. Varying the reactor cross-sectional area Figure 8: A graph displaying the effect of cross-sectional area on catalyst volume Figure 8 shows that increasing the cross-sectional area reduced the catalyst volume, but this reduction was more significant only at the smaller area values. Increasing the area increased the number of catalyst pellets available at the reactor cross-section; therefore a greater reaction rate was initially facilitated as the volume increased. However, the inlet flow was fixed, and beyond a certain area, the flow into the reactor did not utilise the additional pellet area at the cross section; and thus the catalyst volume was less affected. The cross sectional area for the remainder of the investigation was kept at 2m2 because the increase in cross-sectional area above 2m2 does not justify the relatively minimal reduction in catalyst volume. 5.1.3. Variation of catalyst voidage Table 1: Displays catalyst volumes for different values of catalyst voidage Voidage 0.7 0.6 0.5 0.4 0.3 Vc at ÃŽÂ ¾ = 0.54466 (m3) 23.4642 23.4877 23.5399 23.6728 24.1043 Voidage is the ratio of the catalyst volume to the reactor volume. A larger voidage means a higher catalyst pellet density, thereby allowing a smaller catalyst volume. However, increases in voidage past 0.4 did not contribute to any further significant decrease in catalyst volume. For the purpose of subsequent simulations, the voidage was kept to the original 0.4. 5.1.4. Variation of catalyst diameter Table 2: Displays catalyst volumes for different values of catalyst diameter Catalyst Diameter 0.011 0.009 0.007 0.005 0.003 Vc at ÃŽÂ ¾ = 0.54466 (m3) 23.5881 23.6209 23.6728 23.7675 23.9954 It is seen from the data that varying catalyst diameter had a negligible effect on the catalyst volume, suggesting that although the surface area of each catalyst pellet increased, the number of catalyst pellets decreased, and thus the overall catalyst area did not change significantly. It was decided to stick to the original catalyst diameter provided. 5.1.5. Varying temperature and pressure Figure 8: A graph displaying the effect of inlet temperature on catalyst volume for different isobars As the temperature was increased, a decrease in the catalyst volume was observed. At lower pressures, the gradient of the graph (the change in VC with inlet T) was much higher and therefore inlet temperature was more effective at reducing the catalyst volume at lower pressures. This has some implications with respect to cost; if the inlet temperature is increased, there is an electricity cost associated with operating the reactor at this higher inlet temperature, but there is also a saving due to the reduction in catalyst volume. Figure 9: A graph displaying the effect of inlet pressure on catalyst volume for different isotherms As inlet pressure was increased, the catalyst volume decreased. As discussed in the theory, the increase in pressure favoured the forward reaction, thereby increasing the reaction rate per unit volume of catalyst. However, the capital costs spent on reactor materials able to withstand the high pressures have to be taken into consideration in addition to the greater maintenance cost of the catalyst bed (since a higher pressure reduces the longevity of a catalyst). 5.1.6. Results of single stage simulation Table 3: Displays the specifications and feed conditions the optimized single PFR Feed Composition Cross sectional area (m2) Catalyst Diameter (m) Voidage Extent Temperature (K) Pressure (Bar) N2 H2 NH3 In Out In Out 0.23 0.69 0.08 2 0.0007 0.4 0.5447 624.2 796.0 300 298.6 It can be observed that the pressure drop throughout the reaction was rather insignificant compared to the total pressure in the reactor. The optimization values from the single stage plug-flow reactor were essential for designing dual reactors that utilized interstage or cold-shot cooling as the second reactors were designed to follow the reaction path taken by the single stage PFR. The optimum single stage pressure of 300 bar was also the optimum pressure used for the subsequent simulations; the maximum operating pressure tolerable is 300 bar according to the catalyst degradation conditions specified in the simulation objectives. 5.2. Interstage Cooling Figure 10: A graph displaying the extents of reaction for different temperatures. The interstage path for ÃŽÂ ¾1 values of 0.3, 0.34 (optimum), and 0.4 are displayed along with the locus of maximum reaction rates, the equilibrium curve and the locus of rin = rout. Results were obtained for 10 extents between 0.3 and 0.4; these are displayed in the appendix. From the graph above, it can be seen that for all three extents; 0.3, 0.34, 0.4, the reaction in the first reactor moved past the locus of maximum rates and the locus of rIN = rOUT and then approached the equilibrium curve, thereby maximizing conversion. The outlet stream was then cooled to a point along the path taken by the volume minimizing single PFR. The graph thus shows that performance optimization occurred in the interstage cooling design as catalyst volumes in both reactors were minimized. The range of chosen extents for the first reactor, 0.3 0.4 kmol s-1, also proved to be robust, providing well performing reactors with small catalyst volumes (where all reactors had a combined catalyst volume less than half of that of the single stage reactor). Volume reached a minimum of 3.94 m3 when the extent was fixed at 0.34 kmol s-1 with an inlet feed temperature of 737.1K. 5.3. Cold-shot Cooling Table 4 Conditions and results for the optimum cold-shot system Extent Achieved Temperature (K) Catalyst volume (m3) 1st 2nd 1st 2nd In Out In Out Vr1 Vr2 0.2958 0.2489 699 795.769 717.172 796.407 1.523 3.254 (Vc 1 Vc 2 = 1st 2nd Catalyst volume respectively) Figure 11: Catalyst volume minimizing temperatures at specific alpha values During simulation of the cold-shot cooling reactor design, it was deduced that the range of ÃŽÂ ± was restricted from 0.01 to 0.38, beyond which the bulk of the reaction would occur in one of the two reactors, making the other redundant. Optimally, ÃŽÂ ± should be somewhere between the limits of the range; for ÃŽÂ ± = 0.19 and feed temperature at 699K, a minimum overall volume of 4.78 m3 was achieved. It is seen from the graph above that as ÃŽÂ ± deviates from 0.19 and tends towards 0, the first reactor behaves more like a single PFR. The same happens to the second reactor as ÃŽÂ ± tends towards the ÃŽÂ ± upper limit. Increasing the initial feed temperature causes ÃŽÂ ± to increase in order for optimization to occur, while a decrease would bring about the opposite effect. This is because a larger fraction would be required to cool the output from the first reactor to achieve optimization should the reactor operate at a higher temperature. The contrary is true; with a larger ÃŽÂ ±, the initial feed temperature cannot be too low as excessive cooling of the second fraction would occur. 6. Conclusion It can be concluded that the investigation w