Talent Acquisition within Aviation Industry Essay

Talent Acquisition within Aviation Industry - Essay Example The present research has identified that an effective talent acquisition model should focus on identification of recruitment gaps, suggest means of overcoming recruitment gaps, analyse talent acquisition strategy adopted by a company, determine the cost of talent acquisition, and analyse the impact of talent acquisition in a company. Talent acquisition model should also determine the flexibility of talent acquisition in a company. This should occur along with change management and execution of various strategies adopted in the company. This provides room for human resource management of the company to make the necessary adjustments in their talent acquisition strategies. The analysis of Talent Acquisition Model will aid in answering research questions. The model will be applied in the selected aviation industry companies. Talent Acquisition Model aids in identification of challenges and needs of talent acquisition in a company. The model identifies recruitment gaps, as well as identi fying means of addressing the recruitment gaps. According to Sluis, talent management in an organization is crucial in order to ensure that the organization has the potential to accomplish its anticipated goals and objectives. Organization talent management focuses on utilization of skills effectively. Most of multinational organizations focus on talent recruitment at a global scene. However, this recruitment strategy has been impacted by liberalizations policies.

United States History Essay Example for Free

United States History Essay The years from 1929 to 1945 played a big role in the history of the economy, political and social development in the United States. The paper discusses the controversial Great Depression in the United States as well as the country’s involvement in World War II. The important details are written and studied here. INTRODUCTION In 1929, the United States of America has been involved in its own controversies as well as affected the many other countries of the world because of the downfall of its economy. The Presidents of the United States in the controversial periods were involved in trying to uphold the economic situation in the country as well as being a powerful country around the world at that time. The United States of America had to face the Great Depression and WWII at the same time. Only then did the economy and political stability of the country was regained. Isolationism is a foreign economic policy stance applied by the 29th and 30th presidents of the United States, Warren Harding and Calvin Coolidge respectively. This is one policy that many historians blame for the stock market crash in 1929 since it applies the laissez-faire approach. It was also said that the isolationist attitude of the Americans at that time were displayed by both presidents. In the latter years, leaders under the administration of President Roosevelt grew sentiments for the same idea of isolationism. Herbert Hoover took office as the 31st president of the United States of America from March 4, 1929 – March 4, 1933. During his presidency of the United States, the stock market crash of 1929 happened. He believed that interfering with the economy is not a part of the government responsibility and was accused by some critics of taking laissez-faire stance. Due to his disregard of the economic crisis on the nation, many Americans lost their jobs and homes and he was rated very poorly among all the presidents of the United States (Krugman, 2008). Many people believed that President Hoover had huge responsibility in salvaging the country from Great Depression after taking over the presidential office. On the other hand, there are many who believe that he also did well as the president of the US especially in the midst of the economic crisis. His being the Secretary of Commerce before being the president is the standard basis on this argument (Reich, 2008). The Crash of 1929 is undoubtedly one of the most celebrated events that transpired in the economic stability of the United States of all time. The first time the stocks went low continuously is also known as the Black Tuesday. It was on October 29, 1929, just a few months after President Hoover took office. American investors lost billions of dollars worth of investments in a matter of one month. One reason that caused the stock market crash seen by the historians was the rampant buying on margin practice of the people in 1929 as well as confluence factors. Hooverville is what the shanty towns around the United States are called. The Americans who suffered greatly from the Great Depression ended up building shanty towns in America. These towns were named after the President Herbert Hoover by Charles Michelson, chief publicity of the Democratic National Committee. (Kaltenborn, 1956) There were also other notable events that happened within the period of 1929 and 1945. One of these is the Bonus Army also known as the Battle of Anacostia Flats which occurred in June, 1932 where the World War I veterans camped in demonstration outside Washington D. C. during the Hoover’s presidency. One of the important names to note of during this period was Franklin Roosevelt, the 32nd President of the United States of America. He served the United States of America as president from March 4, 1933 to April 12, 1945. He was a figure of the century for being the president to battle the economic crisis as well as the World War II. Under his presidency, he made the New Deal for the recovery of the economy, unemployment and for the reforms the system of the American banking. The New Deal (1933-1936) was a promise from President Roosevelt to the American citizens during his nomination address. After taking office, President Roosevelt immediately worked to provide the Americans what he promised them in his nomination speech. The new deal he had for the country was for the immediate relief. The banks were in panic and so he immediately proposed bill that will put the bank into financial stability. In the New Deal of President Roosevelt, the continuation of major relief program was included. However, it was named as Federal Emergency Relief Administration. The New Deal agencies were the Civilian Conservation Corps, Agricultural Adjustment Administration and the Federal Trade Commission. He also expanded the former President Hoover’s agency, Reconstruction Finance Corporation. Recovery on the economic situation was through federal spending. The reformation of the economy was passed on the 1933 National Industrial Recovery Act (NIRA), whereas the unanimous decision of the U. S. Supreme Court found it to be unconstitutional. However, the president opposed the decision of the Supreme Court. The Banking Holiday was declared by then new President Roosevelt after him taking the seat into office. As the president, he called special Congress session to institute the mandatory bank holiday that would last for four days. The holiday was to give way for the federal inspections of banks on their financial security. The Emergency Banking Relief Act (March 9, 1933) and the amendment of the Trading with Enemy Act are part of the reform under the Roosevelt administration. There was a Second New Deal after the congress election in 1935 bringing more legislation. The â€Å"Alphabet Soup† or the Alphabet Agencies refers to the many acronyms and abbreviations the legislation, programs and agencies linked with President Roosevelt’s New Deal. It was named coined after the alphabet soup noodles. The acronyms and abbreviations the Alphabet Soup refers to the following: Agricultural Adjustment Administration or AAA which is to provide federal subsidies to farmers creating numerous new jobs through the Civil Conservation Corps or CCC, Civil Works Administration or CWA, the Public Works Administration or PWA, and the Tennessee Valley Authority or TVA. The Federal Emergency Relief Administration or FERA was also established to provide relief on the state level, while the National Industrial Recovery Act or NIRA was passed to salvage nations failing factories. Huey P. Long of Louisiana was a senator from January 25, 1932 – September 10, 1935. He is the major critic of the president’s New Deal. According to him, the New Deal that the president was offering at that time is not doing any help for the betterment of the Americans’ situation. He has a totally different principle from Roosevelt. He believed that the Great Depression was because of the income inequality therefore proposing that the tax levy on the rich American must be bigger so that the normal families will survive. He was popular during the first term of President Roosevelt but was assassinated in 1935. From the beginning of World War II in 1939 during the administration of President Roosevelt, rationing system was applied in the United States. This system was applied to gasoline because of the shortage in the Eastern states of America. The reason for this is because in those years, petroleum products were carried by tankers. The dangers on tankers carrying petroleum were faced with operating U-Boats just off the US coast. Moreover, the speed limit of 35 mph to save fuel was imposed. In 1942, tires were also rationed because of the interruption on the supplies of natural rubber. By November in 1943, almost all the basic commodities were supplied to the people through rationing. The bombing of Pearl Harbor on Sunday, December 7, 1941 by the Japanese Empire opened the involvement of the United States Military to World War II. After the military involvement of the United States in World War II, the need for arms and cooperation of the Allied countries’ civilian forces had developed the informal term of home front. This means that the country at war and so are the populace of the country if need be. Hiroshima is the first city in the empire of Japan that was attacked by the United States of America with the nuclear weapon named â€Å"Little Boy†. The attack was made on August 6, 1945 under the executive order of the U. S. President Truman. Over 140,000 people were killed in Hiroshima. The nuclear bombing followed in Nagasaki on August 6, 1945. After six days, the Japanese Empire surrendered to the Allied Powers. On September 2, 1945, the Instrument of Surrender was signed ending the Pacific War and the World War II. Germany signed the Instrument of Surrender also ending World War II in the Europe. REFERENCES: Foner, Eric. Give Me Liberty!. (2004). W. W. Norton Company. New York City. ISBN 0-39-397873-5 Krugman, Paul. (December 28, 2008). Fifty Herbert Hoovers. New York Times. Retrieved May 9, 2009. http://www. nytimes. com/2008/12/29/opinion/29krugman. html? _r=1. Reich, Robert B. (May 2008). Interview with Robert B. Reich. The Duncan Group, Inc. Retrieved May 9, 2009. http://www. duncanentertainment. com/interview_reich. php Kaltenborn, Hans. (1956). It Seems Like Yesterday. G. P. Putnam’s Sons. New York City. Page 88. Emergency Banking Relief Act of 1933. (1933). U. S. Statutes at Large (73rd Congress, 1933). Documents of American History. Retrieved on May 10, 2009. http://tucnak. fsv. cuni. cz/~calda/Documents/1930s/EmergBank_1933. html. Roosevelt, Franklin D. (July 2, 1932). Roosevelts Nomination Address. Franklin and Eleanor Roosevelt Institute. Retreived May 10, 2009. http://www. feri. org/archives/speeches/jul0232. cfm. Hawley, Ellis. The New Deal and the Problem of Monopoly (1966) Fordham University Press. p. 124 World War II Rationing. AmeHistoricalSociety. Retrieved May 10, 2009. http://www. ameshistoricalsociety. org/exhibits/events/rationing. htm#items. Adams, S. Crawford, A. (2000). World War II. First edition. Printed in association with the Imperial War Museum. Eyewitness Books Series. New York, Doring Kindersley Limited. Hakim, Joy (1995). A History of Us: War, Peace and all that Jazz. New York: Oxford University Press. ISBN 0-19-509514-6.

Simulated Moving Bed Technology

Simulated Moving Bed Technology 1. Introduction 1.1. Continuous counter current chromatography Continuous industrial-scale adsorption processes are well known for their efficiency. Very often, the Height Equivalent of a Theoretical Plate (HETP) in a batch operation is roughly three times higher than one find for the continuous mode (Gembicki et al., 2002). The operation of continuous chromatographic counter current apparatus (here-by referred as True Moving Bed, TMB) in particular, maximizes the mass transfer driving force providing a better utilization of the adsorbent, and thus, allowing the use of lower selectivity materials (Ruthven and Ching, 1989) as to operate with an increased productivity (i.e., higher processed throughput using less packing material). A scheme of a TMB unit is shown in Figure 1. Figure 1 A four section True Moving Bed (TMB) unit for the separation of A and B with D as eluent or desorbent (Fructose/Glucose separation). If we define section as the part of the TMB unit where the fluid flow rate is approximately constant (section limited by inlet/outlet streams), then, it is possible to find four different sections with different roles: Section I: Regeneration of the adsorbent (desorption of A from the solid); Section II: Desorption of B (so that, the extract is not contaminated by the less retained component); Section III: Adsorption of A (raffinate clean from the more adsorbed species); Section IV: Regeneration of the eluent/desorbent (adsorption of B from the fluid phase). From Figure 1, one can observed that the counter-current movement of the solid, with respect to the fluid phase, allows continuous regeneration of both the adsorbent in section I as the eluent/desorbent in section IV. Also, the moving bed arrangement allows the achievement of high purity even if the resolution of the two peaks is not excellent, since only the purity at the two tails of the concentration profiles, where the withdrawal ports are located, is of interest. This is contrary to batch chromatography where high resolution is vital in order to achieve high purity. Nevertheless, with this counter current mode of operation is necessary to circulate not only the fluid phase but also the solid. The solid motion inside of the column and the consequent recycle presents some technical problems, namely: equipment abrasion, mechanical erosion of adsorbent and difficulties in maintaining plug flow for the solid (especially in beds with large diameter). From a technical point of view, this clearly limits the implementation of such technology. 1.2. The Simulated Moving Bed (SMB) concept In order to avoid this issue, a sequence of fixed bed columns was conceived (Broughton and Gerhold, 1961) in which the solid phase is at rest in relation to a fixed referential, but where a relative movement between both phases is experienced by switching the inlet and outlet fluid streams to and from the columns from time to time (in the direction of the fluid flow). In the simplest operating mode, the period that a certain operating configuration prevails is called the switching time, . Since the solid flow is avoided, although a kind of counter-current movement is created relatively to the fluid, this technology is called Simulated Moving Bed (SMB). Consider that at certain moment in the operation of an SMB, the positions for the inlet of feed and desorbent and outlet of products is represented by Figure 2a. Assume also the simplest operating mode (synchronous advance of all streams) and one column per section. After a period of time equal to the switching time, the injection and withdrawn points all move one column in the direction of the fluid flow (Figure 2b). When the initial location of injection/collection of all the streams is reencountered, we have completed one cycle (in a four equally zoned SMB, it takes to complete one cycle, where is the number of columns in each one of the four sections). As it is possible to see in Figure 2, during one cycle the same column is in different sections, assuming therefore different roles in the separation process. Figure 2 Schematic representation of a 4 columns SMB unit operating over a complete cycle, from 0to (with representing the ports switching time); (a) period of the first switch; (b) period of the second switch and (c) a TMB unit. As mentioned before, the continuous movement of inlet and outlet lines into and from the column is almost impractical, therefore discreet jumps (with the length of one bed, during ) have to be applied. The analogy between SMB and the TMB is then possible by the introduction of the relative velocity concept, where , with the fluid interstitial velocity in each section in the TMB, the interstitial velocity in the SMB unit and the solid interstitial velocity in the TMB. The solid velocity is evaluated from the switching time interval value in the SMB as , being the column length. As consequence, The internal flow rates in both apparatus are not the same, but related by where and represent the internal liquid flow-rates in the SMB and TMB, respectively, is the bulk porosity and the column volume. 1.3. SMB Applications Industrially, SMB applications can be regarded as â€Å"Old† and â€Å"New†, associated with petrochemical and pharmaceutical/fine chemistry fields, respectively (Sà ¡ Gomes et al., 2006d). Among the first applications of SMB technology (back to 1960s) are the ones implemented by the UOP Inc. (Des Plaines, IL-USA) with the Sorbex ® processes, such as: the Parex ® unit for separation of p-xylene from mixtures with its C8-isomers (Broughton et al., 1970), separation also performed by the Aromax ® process from Toray Industries (Tokyo, Japan) (Otani et al., 1973) and the Eluxyl ® process by Axens/IFP (Institut Franà §ais du Pà ©trole, France) (Ash et al., 1994); the Ebex ® for the separation of EthylBenzene (EB) from a mixed of C8-aromatic isomers (Broughton, 1981); the Molex ® for the separation of n-paraffins from branched and cyclic hydrocarbons; and the Olex ® process to separate olefins from parafins; the Cresex ® and Cymex ® for the separation of p-cresol and p-cymene from its isomers, respectively. The application of SMBs in the sugar industry is also substantial, with the Sarex ® process, for the separation of fructose from the corn syrup with dextrose and polysaccharides on polystyrene-divinylbenzene resins in calcium form (Broughton, 1983); or as patented by Japan Organo Co. (Japan), (Heikkilà ¤ et al., 1989); by Amalgamated Sugar Company LLC, also known as the Snake River Sugar Company (Boise, ID-USA), (Kearney and Mumm, 1990, , 1991). In the last decade, particularly in the area of drug development, the advent of SMB has provided a high throughput, high yield, solvent efficient, safe and cost effective process option. Although it had long been established as a viable, practical, and cost-effective liquid-phase adsorptive separation technique, the pharmaceutical and biomolecule separations community did not show considerable interest in SMB technology until the mid-1990s. The application of the SMB concept to the fine chemical separations in the earlier 90s, led to the second â€Å"boom† on the number of applications of SMB technology (Negawa and Shoji, 1992; Nicoud et al., 1993; Kusters et al., 1995; Rodrigues et al., 1995; Cavoy et al., 1997; Francotte and Richert, 1997; Guest, 1997; Pais et al., 1997a; Pais et al., 1997b; Francotte et al., 1998; Grill and Miller, 1998; Lehoucq et al., 1998; Pais et al., 1998; Dapremont et al., 1999; Miller et al., 1999; Nagamatsu et al., 1999; Nicoud, 1999a, 1999b; Pedefe rri et al., 1999; Strube et al., 1999; Juza et al., 2000; Kniep et al., 2000; Wang et al., 2001), among other â€Å"pioneers†. Daicel Chemical Industries, Ltd (Japan) first published the resolution of optical isomers through SMB (Negawa and Shoji, 1992). Since then, several are the SMB based processes already approved by the Food and Drug Administration (FDA) and others regulatory agencies. Examples includes renowned products such as: Biltricide (Praziquantel) Cipralex/Lexapro (Escitalopram), Keppra (Levetiracetam), Modafinil/Provigil, Taxol (Paclitaxel), Xyzal (Levocetirizine), Zoloft (Sertraline), Zyrtec (Cetirizine), Celexa/Citrol/Cipram (Citalopram), Prozac (Fluoxetine hydrochloride), (Abel and Juza, 2007) o paper de real SMB e rajendran, among others biological separation, with a particular emphasis in protein separations meteer referencias a biologias e proteinas. Given the importance of such technique, this work reviews different operating SMB modes; design, modeling and optimization techniques; and addresses an example of the design, construction and operation of an SMB unit. 2. SMB modes of operation So far, only the so-called conventional SMB mode of operation has been considered, which indeed means that each section has a fixed number of columns and there is no variation on the pre-established inlet/outlet flow rates or the switching time value. However, over the last decades some non-conventional SMB operating modes were proposed, developing the range of the applications of SMB technology and extending further its potential. Some of these operating modes, worthy of note, are listened in the following Sections. 2.1. Asynchronous shifting SMB (the Varicol ® process) The asynchronous shifting SMB or Varicol ® process (Adam et al., 2000; Bailly et al., 2000; Ludemann-Hombourger et al., 2000; Ludemann-Hombourger et al., 2002) commercialized by Novasep (Pompey, France), became one of the more studied and used processes of the so-called non-conventional SMB modes of operation. Instead of a fixed unit configuration with constant section length, the Varicol ® operating mode is performed by the implementation of an asynchronous inlet/outlet ports shift, providing a flexible use of each section length, Figure 3. Figure 3 [11.51.51] Asynchronous SMB for a complete cycle; section II has 1 column during the first half of the switching time and 2 columns in the remaining time (within a switching time period), thus 1.5 columns; the opposite happens to section III. By means of Varicol ® mode of operation it is possible to increase the productivity value up to 30% more than the classical SMB apparatus, principally when operating under a reduced number of columns (Toumi et al., 2002; Zhang et al., 2002b; Pais and Rodrigues, 2003; Subramani et al., 2003b, 2003a; Toumi et al., 2003; Yu et al., 2003b; Sà ¡ Gomes et al., 2006d; Mota et al., 2007b; Rodrigues et al., 2007a; Sà ¡ Gomes et al., 2007b; Zhang et al., 2007). 2.2. Partial-Feed, Partial-Discard With the Partial-Feed mode of operation two additional degrees of freedom are introduced: the feed length and the feed time (Zang and Wankat, 2002a; Zang and Wankat, 2002b). Feed during a given feed length period will consequently influence the raffinate and extract flow rates are along the time. Also referred in the literature is the Partial-Discard (or partial withdraw) operating mode, where just a part of the outlet products is used in order to improve the overall purity (Zang and Wankat, 2002b; Bae and Lee, 2006), or with the partial recirculation of the outlet products back to the feed (Kessler and Seidel-Morgenstern, 2008a; Kessler and Seidel-Morgenstern, 2008b; Seidel-Morgenstern et al., 2008). The ISMB (Improved SMB) mode of operating, commercialized by the Nippon Rensui Co. (Tokyo, Japan) and FAST â€Å"Finnsugar Applexion Separation Technology†, now Novasep-France, is also well known (Tanimura et al., 1989). In this process, during a first step the unit is operated as a conventional SMB but without any flow in section IV; in the second step the inlet and outlet ports are closed and the internal flow through the four sections allowing the concentration profiles to move to adjust their relative position with respect to the outlet ports (Rajendran et al., 2009). Meter referencias do mazzotti e nova de sa gomes Another novel non-conventional mode of operation, the Outlet Swing Stream-SMB (OSS) (Sà ¡ Gomes and Rodrigues, 2007), was developed under the framework of this thesis and is latter detailed in Chapter 3. 2.3. PowerFeed and ModiCon The modulation of the section flow rates (PowerFeed) was originally proposed by Kearney and Hieb (1992) and later studied in detail by other authors (Kloppenburg and Gilles, 1999b; Zhang et al., 2003b; Zhang et al., 2004b; Kawajiri and Biegler, 2006b). Another SMB operating concept, based on the feed concentration variation within one switching interval, was suggested by Schramm et al., (2002; 2003b) known as the ModiCon. The use of auxiliary feed tanks, where section flow rate flows into a tank to dissolve solid raw materials and fed into section III, has also been studied (Wei and Zhao, 2008). The cross combination of PowerFeed, Modicon and Varicol modes of operation is also a recurrent research matter, principally of optimization studies (Zhang et al., 2004a; Arau?jo et al., 2006a; Rodrigues et al., 2007b), providing more degrees of freedom and allowing better performance values. 2.4. Two Feed or MultiFeed SMB and Side Stream SMB Recently, the introduction of multi feed streams in the SMB area, by analogy with distillation columns, led to the formulation of the Two Feed SMB, or MultiFeed, operating mode presented by Kim (2005) and later studied by Sà ¡ Gomes and Rodrigues (Sà ¡ Gomes et al., 2007b; Sà ¡ Gomes and Rodrigues, 2007). Also multi extract/raffinate are referred in the literature (Mun, 2006), known as side stream SMB (Beste and Arlt, 2002). These techniques, combined with the distillation know-how for the optimum location of multiple feeds, can allow the development of more efficient SMB processes. 2.5. Semi Continuous, Two and Three zones SMB There are several semi continuous SMB apparatus that operate with two-zone, two or one-column chromatograph, with/or recycle, analogous to a four-zone SMB(Abunasser et al., 2003; Abunasser and Wankat, 2004; Arau?jo et al., 2005a; Arau?jo et al., 2005b; Jin and Wankat, 2005b; Mota and Arau?jo, 2005; Arau?jo et al., 2006b; Arau?jo et al., 2007; Rodrigues et al., 2008b), that allow a reasonable separation, some allowing centre cut for ternary or quaternary separations (Hur and Wankat, 2005b, 2005a, , 2006a, 2006b; Hur et al., 2007), under reduced equipment usage. The discontinuous injection in a system with 2 or more columns, based on the concept of simulated adsorbent movement, as been applied by Novasep under the denomination of Cyclojet ®, Hipersep ®, Supersepâ„ ¢ (Supersep MAXâ„ ¢ with Super Critical CO2) and Hipersep ®, (Grill, 1998; Valery and Ludemann-Hombourger, 2007). 2.6. Gradient SMB As a further possibility for increasing the productivity, the introduction of gradients in the different separation sections of the SMB process is also described in literature. The gradient mode was suggested firstly for the SMB-SFC (SMB-supercritical fluid chromatography) process, where the elution strength can be influenced by a pressure gradient (Clavier and Nicoud, 1995; Clavier et al., 1996). Nowadays, there are more gradient-variants that allows the variation solvent elution strength by changing the temperature, the pH-value, the content of salt or the modifier concentration (Jensen et al., 2000; Antos and Seidel-Morgenstern, 2001; Migliorini et al., 2001; Abel et al., 2002; Antos and Seidel-Morgenstern, 2002; Abel et al., 2004; Ziomek and Antos, 2005; Mun and Wang, 2008a), or as in Rodriguess group with the purification of proteins by Ion Exchange-SMB (IE-SMB) (Li et al., 2007; Li et al., 2008). Also worth of note is the MCSGP (Multicolumn Counter-current Solvent Gradient Puri fication) process (Aumann and Morbidelli, 2006; Strohlein et al., 2006; Aumann and Morbidelli, 2007; Aumann et al., 2007; Aumann and Morbidelli, 2008; Mà ¼ller-Spà ¤th et al., 2008), commercialized by ChromaCon AG (Zà ¼rich, Switzerland), which combines two chromatographic separation techniques, the solvent gradient batch and continuous counter-current SMB for the separation of multicomponent mixtures of biomolecules. 2.7. Hybrid-SMB: SMB combined with other processes It is possible to improve the performance of SMB units by integrating it with other different separation techniques. The more simple application of this approach is to combine in series the two different processes and then recycle back the outlets between (or within) the different units (Lorenz et al., 2001; Amanullah et al., 2005; Kaspereit et al., 2005; Amanullah and Mazzotti, 2006; Gedicke et al., 2007). Among these, an interesting hybrid SMB was presented by M. Bailly et al., (2005; Abdelmoumen et al., 2006), the M3C process; or the similar process: Enriched Extract operation (EE-SMB) (Paredes et al., 2006), in which a portion of the extract product is concentrated and then re-injected into the SMB at the same, or near to, the collection point. The use of SMB-PSA apparatus is also referred in the literature for gas phase separations, (Rao et al., 2005; Sivakumar, 2007; Kostroski and Wankat, 2008). The use of two SMB units with concentration steps between, for the separation of bi nary mixtures, was also developed under the denomination of hybrid SMB-SMB process (Jin and Wankat, 2007a). 2.8. The SMBR multifunctional reactor The integration of reaction and separation steps in one single unit has the obvious economical advantage of reducing the cost of unit operations for downstream purification steps. Besides reactive distillation, reactive extraction or membrane reactors, the combination of (bio)chemical reaction with SMB chromatographic separator has been subject of considerable attention in the last 15 years. This integrated reaction-separation technology adopts the name Simulated Moving Bed Reactor (SMBR). Several applications have been published considering the SMBR: the enzymatic reaction for higher-fructose syrup production (Hashimoto et al., 1983; Azevedo and Rodrigues, 2001; Borges da Silva et al., 2006; Sà ¡ Gomes et al., 2007a); meter a dos FOS the esterification from acetic acid and -phenethyl alcohol and subsequent separation of the product -phenetyl acetate (Kawase et al., 1996), or methyl acetate ester (Lode et al., 2001; Yu et al., 2003a); the synthesis and separation of the methanol fro m syngas (Kruglov, 1994); the esterification of acetic acid with ethanol (Mazzotti et al., 1996b); the lactosucrose production (Kawase et al., 2001); the MTBE synthesis (Zhang et al., 2001); the diethylacetal (or dimethylacetal) synthesis (Silva, 2003; Rodrigues and Silva, 2005; Silva and Rodrigues, 2005a; Pereira et al., 2008); the ethyl lactate synthesis from lactic acid and ethanol (Pereira et al., 2009a; Pereira et al., 2009b); the biodiesel synthesis (Geier and Soper, 2007) falta uma; or the isomerization and separation of p-xylene (Minceva et al., 2008) faltam os franceses, are examples that prove the promising potential of this technique. Depending on the reactive system some interesting arrangements of the general SMBR setup can be found in the literature, a more detailed review of several SMBR applications can be found elsewhere (Minceva et al., 2008). 2.9. Multicomponent separations The application of SMB technology to multicomponent separations has also been an important research topic in the last years. The common wisdom for such multicomponent process is the simple application of SMB cascades (Nicolaos et al., 2001a, 2001b; Wankatt, 2001; Kim et al., 2003; Kim and Wankat, 2004); nevertheless, there are some non-conventional operation modes that proved to have interesting performance, as the one introduced by the Japan Organo Co. (www.organo.co.jp), called JO process (or Pseudo-SMB); this process was discussed in detail (Mata and Rodrigues, 2001; Borges da Silva and Rodrigues, 2006, , 2008) and (Kurup et al., 2006a). The process is characterized by a 2-steps operation: (a) in the first step the feed is introduced while the intermediary product is recovered with the whole unit working as a fixed bed; (b) during the second step the feed stopped, the unit works as a standard SMB and the less and more retained products are collected, see Annex I for details. The u se of two different adsorbents (Hashimoto et al., 1993), two different solvents (Ballanec and Hotier, 1992), or a variation of the working flow rates during the switching period (Kearney and Hieb, 1992), were also proposed. 2.10. SMB Gas and Super Critical phases Most of the industrial applications of SMB technology operate in the liquid phase; nevertheless, SMBs can also be operated under supercritical conditions; where a supercritical fluid, typically CO2, is used as eluent offering a number of advantages namely reduction of eluent consumption, favourable physicochemical properties and lower pressure drop and higher column efficiency (Clavier and Nicoud, 1995; Clavier et al., 1996; Denet and Nicoud, 1999; Depta et al., 1999; Denet et al., 2001; Johannsen et al., 2002; Peper et al., 2002; Peper et al., 2007). Also in the gas phase the recent developments have been remarkable (Storti et al., 1992; Mazzotti et al., 1996a; Juza et al., 1998; Biressi et al., 2000; Cheng and Wilson, 2001; Biressi et al., 2002; Rao et al., 2005; Lamia et al., 2007; Mota et al., 2007b; Sivakumar, 2007; Kostroski and Wankat, 2008). Meter a do propano propylene 3. SMB design, modeling, simulation and optimization Over the last 50 years, design, modeling, and optimization of chromatographic separation processes have been frequent research subjects. As consequence, several modeling methods, strategies and approaches have been developed, the more relevant are reviewed in this section. 3.1. Design strategies The design of an SMB based separation involves taking decisions at many levels, from the configuration of the unit (number of columns per section, column and particle size) to operating conditions (feed concentration, switching time, internal flow rates). Although simulation can be exhaustively done until the right combination of parameters is found for the expected performance, it is useful to have a design method that will provide a preliminary estimation of the optimum operating point, followed by simulation and/or optimization, (Sà ¡ Gomes et al., 2009a). The equivalence between TMB and SMB can be quite useful in the SMB design procedure. Recalling the role of each SMB section (Figure 2c), one can state a set of constraints that will limit the feasible region and allow a complete separation (recover of the more retained species (A) in the extract stream, the less retained one (B) in the raffinate port, and regeneration of the solid in section I as fluid in section IV). Where represents the solid flow rate, the average solid concentration of species in section and the bulk fluid concentration of species in section . The flow rates constraints in Eq. 1b and 1.c will identify the separation region (section II and III), while Eq. (1 a) and Eq. (1 d) the regeneration one (section I and IV). Usually, the fluid and solid velocities in each section are combined into one only operating parameter, such as the from Morbidellis group or the , as used by Ruthven (1989). The identification of constrains, Eq. (1 a) to Eq. (1 d), led to the appearance of several design methodologies, which are usually approximated and/or graphical, providing a better insight to the possible operating regions. From the plates theory and McCabe-Thiele diagrams (Ruthven and Ching, 1989); passing by the analytical solutions for a linear adsorption isotherms system in presence of mass transfer resistances (Silva et al., 2004); to the determination of waves velocities as in the Standing Wave Design (SWD) methodology (Ma and Wang, 1997; Mallmann et al., 1998; Xie et al., 2000; Xie et al., 2002; Lee et al., 2005). A particular emphasis should be given to the strategy developed for binary and multicomponent separations modeled by linear and non-linear isotherms as in (Storti et al., 1989b; Storti et al., 1 993; Mazzotti et al., 1994; Storti et al., 1995; Mazzotti et al., 1996c; Mazzotti et al., 1997b; Chiang, 1998; Migliorini et al., 2000; Mazzotti, 2006b), the so-called â€Å"Triangle Theory†, where the term is treated by assuming that the adsorption equilibrium is established everywhere at every time (Equilibrium Theory, (Helfferich, 1967; Klein et al., 1967; Tondeur and Klein, 1967; Helfferich and Klein, 1970), resulting in a feasible separation region formed by the above constraints Eq. (1 b) and Eq. (1 c), which in the case of linear isotherms takes the shape of a right triangle in the plane, Figure 4, (or a triangle shaped form with rounded lines in non-linear isotherms case), and a rectangular shape in the plane. Recently, this methodology was also extended for the design of SMB units under reduced purity requirements, in which the separation triangle boundaries are â€Å"stretched† to account for different extract and/or raffinate purities (Kaspereit et al., 2007; Rajendran, 2008). Figure 4 â€Å"Triangle Theory†, separation and regeneration regions for linear isotherms, where represents the Henry constant for linear adsorptions isotherms (A: the more retained and B: the less retained species), is the intraparticle porosity; case of (S,R)Tetralol enantiomers, see Section 4.3.2. Nevertheless, the inclusion of mass transfer resistances can deeply affect the result of the design. By taking into account all mass transfer resistances, and running successive simulations, it is possible obtain more detailed separation/regeneration regions, as well as the separation study carried out for three different sections (II, III and I) or (II, III and IV) allowing the analysis of solvent consumption or solid recycling, as proposed in the â€Å"Separation Volume† methodology, (Azevedo and Rodrigues, 1999; Rodrigues and Pais, 2004a), or the influence of the solid flow rate in the separation region (Zabka et al., 2008a). 3.2. Modeling and simulation Generally, one can model a chromatographic separation process, and consequently an SMB unit, by means of two major approaches: by a cascade of mixing cells; or a continuous flow model (plug flow or axial dispersed plug flow, making use of partial differential equations derived from mass, energy and momentum balances to a differential volume element ), (Rodrigues and Beira, 1979; Ruthven and Ching, 1989; Tondeur, 1995; Pais et al., 1998). Each of these approaches can include mass transfer resistances, thermal, and/or pressure drop effects. Nevertheless, most of the recent literature concerning SMB processes just makes use of the continuous approach, detailing the particle diffusion and/or film mass transfer (the Detailed Particle Model), or using approximations to the intraparticle mass transfer rate in a similar way as the Linear Driving Force (LDF) approach presented by Glueckauf (1955a), (Guiochon, 2002). One can argue that an SMB unit is no more than the practical implementation of the continuous counter current TMB process, Figure 2. Consequently, the equivalence between the TMB and a hypothetical SMB with an infinite number of columns can be used in the modeling and design of SMB units. However TMB model approach will just give reasonable results if a considerable number of columns per section is present. The SMB model approach represents an SMB unit as a sequence of columns described by the usual system equations for an adsorptive fixed bed (each column ), thus represented by a PDE system. Nevertheless, the nodes equations can be stated to each section, making use of the equivalence between the interstitial velocity in the TMB and SMB, and thus: The issue here is that, due to the switch of inlet and outlet lines, the boundary conditions to a certain column are not constant during a whole cycle but change after a period equal to the switching time. Since the model equations are set to each column , one will obtain the concentration of species in the begin of each section , , from the following node mass balances: Considering now . This set of equations continues to progress in a similar way (shifting one column per ), until , repeating then from the first switch. As for the TMB model approach, both the Detailed Particle Model and LDF approach can be used with the SMB model approach; nevertheless, and for the sake of simplicity, just the last is detailed in this work. The LDF approximation can now be obtained from , and thus obtaining for the bulk fluid mass balance: and for the mass balance in the particle, with the respective initial: and boundary conditions: where the adsorption equilibrium isotherm is: As a consequence one obtains discontinuous solutions, reaching not a continuous Steady State but a Cyclic Steady State (CSS). By applying the SMB model approach, both the Detailed Particle as LDF strategies, to the case study mentioned before, one obtains the CSS concentration profiles over a complete switching time, Figure 6. 3.3. Performance parameters The performance of the SMB unit for a given separation is usually characterized by the following parameters: purity, recovery, productivity per the amount adsorbent volume and eluent/desorbent consumption per mass of treated product. The definitions of all these performance parameters, for the case of a binary mixture, are given bellow: Purity (%) of the more retained (A) species in extract and the less retained one (B) in the raffinate stream, over a complete cycle (from to ): Recovery (%) of more retained (A) species in extract and the less retained one (B) in raffinate stream, again over a complete cycle: the productivity per total volume of adsorbent : the eluent/desorbent consumption : These parameters hold for both SMB and TMB model approaches; nevertheless, one can simplify: in the SMB model strategy the same equations can be stated for a switching time period (from to ) if the unit is symmetrical, i.e., there are no differences between each switching time period (either due to the implementation of non-conventional modes of operation, or to the use of more detailed models accounting for dead volumes or switching time asymmetries); in the TMB model approach there is no need of the integral calculation, since the solutions from this model strategy are continuous and thus, the performance parameters constant over the time (at the steady state). 3.4. Optimization Usually one can classify the optimization of SMB units according to the type of objective functions: (i) optimization of performance parameters (productivity, adsorbent requirements or desorbent/eluent consumption for given purities and/or recovery requirements); (ii) optimization based on the separation cost. In case (i) each objective function, based on a different set of performance parameters, can lead to a different optimum solution; therefore multi-objective functions procedure should be considered; in the second case (ii) all those different performance parameters can be homogenized/normalized by the separation cost, where separation dependent costs (adsorbent, plant, desorbent/eluent recovery cost, desorbent/eluent recycling, feed losses) and separation independent costs (wages, labour, maintenance, among others) are taken into account and weighted by cost factors, which sometimes are difficult to characterize (Jupke et al., 2002; Chan et al., 2008). To solve these problems, the use of powerful optimization algorithms, such as: IPOPT (Interior Point OPTimizer, (Wa?chter and Biegler, 2006), employed for liquid as gas phase SMB separations (Kawajiri and Biegler, 2006b, 2006a; Mota et al., 2007a; Mota and Esteves, 2007; Rodrigues et al., 2007b; Kawajiri and Biegler, 2008a, 2008b); the commercial package gOPT from gPROMS with a Single (or Multiple) Shooting-Control Vector Parameterization, used in the two level optimization of an existing Parex ® unit (Minceva and Rodrigues, 2005), for ageing analysi

Improving Student Perception of Grammar Essay -- English Writing Teach

Its time to come clean, face the facts and admit the truth - students are scared of grammar. From the days of crayons and nap time straight through high school they always hope and pray that a random fire drill, a.k.a. a gift from God, will disrupt the dreaded grammar lessons and exercises. As the semesters continue to pass by students become elated as grammar turns into nothing more than a minute beep on the radar screen that is the weekly lesson plan. However, nearly every student walks into English class dealing with the fear that he will be called on to explain even the simplest rules of possession or number. So why do most students fear and loathe the perplexities of grammar? Perhaps this trepidation has something to do with the fact that most teachers treat grammar like the ‘redheaded step son’ of the English curriculum; hiding its study somewhere between spelling exercises and vocabulary worksheets. While most teachers avoid discussing grammar, or discuss it incor rectly, they still threaten students with low marks if such mistakes rear their ugly little heads in class assignments. The way we, as scholars, view the discussion, acquisition and knowledge of grammar must be modified to suit the realities of the modern classroom and world. Grammar should be seen through the lens of the entire writing process to make the students use of grammar seem completely natural and easy. Although every coin has two sides, the research arguing against the formal teaching of grammar in the classroom appears stronger than that which supports the old regime’s strict approach to grammar. However, logic dictates that this argument will not be settled merely by choosing sides. Perhaps some middle ground can be found between the militantly form... ...rt with some creative planning. Perhaps a weekly prize contest can be held to see what student can pick out a grammar mistake in a newspaper or magazine. Then this mistake can be turned into a mini lesson without becoming boring or overbearing. Teachers simply need to remember that it’s ok to throw away the worksheets from 1975 and put down the trusty textbook for a fresh approach to grammar. Bibliography Hartwell, Patrick. "Grammar, Grammars, and the Teaching of Grammar." In Cross Talk in Comp Theory. Edited by Victor Villanueva. National Council of Teachers of English. Urbana: 1997. Weaver, Constance. Teaching Grammar in Context. Boyton/Cook Publishers. Portsmouth: 1996. Whorf, Benjamin Lee. "The Relation of Habitual Thought and Behavior to Language." In Critical Theory Since 1965. Edited by Hazard Adams. Florida State University Press. Tallahassee: 1986.

Unit 2 Cache Level 2 Coursework

Shalini Karsan 10/680 846 Unit 2- The developing child. D1- Describe the expected stage of social development of the children aged 4 years. The child at 4 years will start to develop a knowledge about different genders e. g. females and males. They can make friends, and they are also interested in having them. This age group, should know how negotiate, and to give and take objects.D2- Describe the expected stage of social development of the children aged 5 years. They can help and take responsibility of other children, for example helping them out in the setting. Most 5 year old children like working in groups, with others as this will let them interact amongst each other. At this age friends are important, they are independent. When playing games in the setting they can understand the rules of the game. D3- Describe one suitable method of observing and recording the social development of children aged 5 years.The suitable method of observing children at the age of 5 years, at the s ocial development stage, is to record it by a narrative observation. It can be used to record social development. A narrative ‘observation is a detailed account of everything that you see the child doing’ (Thornes. N, 2009) When doing observations in the setting, the child’s name should not be included because of confidentiality. The children should be named as ‘A’ and ‘B’ instead of the name. ‘You should record the date you made your observation. ’(Thornes.N, 2009) D4- Explain one advantage and one disadvantage of this method of observing children. The advantages of this observation are so that practitioners understand the child as individuals, and their likes and dislikes. They can collect relevant information about the children or child. They can also know what development stage the child at. The disadvantage of this observation is that it could interfere with confidentiality. The teachers may not want this information to be observed, as it can be passed around to other people.D5- Identify the main influences that may affect the social development of children. Children’s social development can be affected by negative influences such as, speech and language, money problems, English as a second language, violence abuse, disability, family break ups, and moving house. It can also be affected by positive influences such as children making new friends in their new setting, they have started. D6- Describe how snack and mealtimes can support the social development of children.Snack and mealtimes can support social development by the children washing their hands before eating their snack in the setting, or meal in their home; they can talk amongst each other, and the teacher’s this will allow the children to socialise freely. They can be taught how to share and wait for their turns to take their meal or snack, they can serve themselves at the table, this will give them a choice to pick what th ey would like to eat. Table manners can be involved because it teaches the child to do things independently. D7- Show an understanding of diversity and inclusive practice.As a practitioner we should encourage a child to explore. Practitioners can show an understanding of diversity and inclusive practice, by mixing all the genders together when the children are doing their activity. All children should be treated equally, despite of their ethnicity, ability, religion and needs. ‘A stereotype is a fixed image of a group of people’ (Tassoni. P 2007). Stereotyping, should not be shown, as children may get the wrong idea of the opposite sex. Children with (SEN) Special Education Needs will need extra support in the activities, played in the setting.

Comunication for Distance Learning

Hi Mom, This morning after I left your house, in my way to work I had a little car accident. I am okay mom, not to worry, nothing happened to me or the babies. This lady was taking on the phone, and of course she never saw my car. Now I understand why you are always telling me not to use my cell phone when driving. Thank god, RJ, Madison and Melanie are ok, just a little bit scare (yes mom they had seatbelt). I’m taking the day off to deal whit my insurance. Love you Write a formal letter of 100 to 200 words to the insurance company .Use salutations and sign-offs where appropriate. October 2, 2012 To: UNITED AUTOMOBILE INSURANCE P. O. BOX 60125 NORTH MIAMI BEACH, FLORIDA, 33160 From: Meghan Serra 4928 lane 8 ct Cape coral, Florida, 33891 Policy number: UHD 565635695326 Dear Sir or Madam: I am writing to inform you that I was involve in a car accident with another vehicle on September 28, 2012. I was driving on Skyline from east to west toward Pelican road. On this day I was dr iving my black 2005 Toyota, a red 2003 ford explorer rear ended my car in the back left.There was not damage to the other car and no one was injured at the moment of the accident, but I have some minor dents on my car . The other person involved in the accident claims, that she did not saw my car. I quickly call the police to proceed with the report. The report number is 251233, please let me know if more information is needed. Sincerely Meghan. Communicating for Distance Learning ( Part 2) Anthony It is really important to use inclusive language when communicating in class forum because this is the only way to connect with classmates and instructor.This is how we can get our point across and engage whit each other s. I also recommend avoiding language that is exclusive to one group, trying to use language that is inclusive, nonsexist, or gender neutral. I suggest you in the future when communicating either in a forum, email o text to follow two simple rules. First, you should never address an audience like you mention in your email â€Å"Hi guys â€Å", people can get really offended. Secondly when you said â€Å"I was surprised because she had a lot of good things to say â€Å"you sound really racist towards woman, that comment did not have anything to do with the topic .Three pointers for how to prevent these mistakes in the future you should always read what you write twice, check for spelling capitalization and proper use of grammar. Second keep in mind your audience; do not personalize your message. And last be professional and respectful of others opinions and beliefs. Communicating for Distance Learning (Part 3) Written tone is very important; this is the only representing that my classmates have of myself.Tone is present in all type of communication activities, the tone of the message is a reflection of me and it does affect how the reader will perceived my message. In my opinion I think is beneficial to Taylor each and every communication I write , and question the audience before you start the process of writing. Ask yourself, who will read my document? Or what is the purpose of my document? And who is my audience? Tailor your message to your audience to improve their comprehension and realize the different tone to use whit families and people in the work environment.