High Stakes Testing Essay

Tests are a very important tool for measuring achievement; therefore, they should be part of a system which provides equitable learning access to all students. The No Child Left Behind Act of 2002 (NCLB) which requires states to develop accountability systems and provide assessment of the students’ performance in order to receive federal funding accordingly has led to the necessity of implementing large-scale testing. The goal of using these types of tests can be considered praiseworthy if – the tests are designed in such a way that all students are tested on a curriculum they have had a fair opportunity to learn (especially racial and ethnic minority students or students with a disability or limited English proficiency) – the tests are scored properly, taking into account that the test scores of those students with limited English skills should be interpreted in accordance with those limitations – the tests are used appropriately. For example, a test that has been validated only for diagnosing strengths and weaknesses of individual students should not be used to evaluate the educational quality of a school. The public schools of North Carolina, for example, carry a very high-stakes accountability program known as â€Å"The New ABCs of Public Education. † which has had a major impact on curriculum, instruction, assessment, and school personnel throughout the state. The program requires: End-of-Grade Tests (3-8 and 10), End-of-Course Tests (on Algebra I, Algebra II, Biology, Chemistry, Civics & Economics, English I, Geometry, Physical Science, Physics, U. S. History, NCCLAS ), Tests of Computer Skills, Competency Tests, Writing Assessments Grades 4, 7, and 10, IDEA ® English Language Proficiency Tests. Each North Carolina school, as well as any school in any other state has to give itself an annual report card, with assessment results broken down by poverty, race, ethnicity, High Stakes Testing 2 disability, and English-language proficiency. In this way, the race for more and better information about school performance sets off. More attention should be paid to the quality of data educational authorities receive as it is a fact that there are schools which are painting a picture prettier than reality, thus misleading authorities, taxpayers and what is even worse, keeping students trapped in low quality institutions. Under NCLB, if schools fail to make adequate yearly progress on state tests for three consecutive years, students can use federal funds to transfer to higher-performing public or private schools, or to obtain supplemental education services from providers of their choice but this could not be possible if the low-quality institutions they attend remain invisible under misleading reports of pretended excellence. In many districts, raising test scores are the most important indicators of school improvement so teachers feel the pressure to ensure that test scores go up. Knowing that schools that fail for four to five consecutive years may face state takeovers, have their staffs replaced, or be bid out to private management some teachers narrow the curriculum and teach only what is covered on the test. There are many issues that should be taken into account when it comes to evaluating high stake assessment. One of them is the reliability of high stake tests which is definitely at risk when large subject domains (mathematics, language arts) are measured with relatively few questions and a narrow focus on skills and knowledge. Major decisions like getting a diploma or being promoted to the next grade require a balance of information including in-class performance, interviews, observation, projects, and class work. Perhaps the most important critical claim is that standardized tests do not measure critical thinking, problem solving, creativity, and other similar important aspects of intelligence. Students who are perfectly intelligent can perform poorly in high-stakes testing, and this can have serious consequences for the student as well as his or her school. High Stakes Testing 3 In my opinion, the first of the three most important issues in high stakes testing is the type of test used. Large-scale high-stakes testing programs are primarily focused on serving the goals of norming and selection rather than student mastery of content and problem-solving (Pellegrino, Chudowsky, & Glaser, 2001). These two types of testing are almost impossible to reconcile. A second issue of great importance is assessment of learning versus assessment for learning (Stiggins, 2002) There is a distinction between high-stakes testing (assessment of learning) and the formative assessment techniques that teachers may use throughout the year to foster learning (assessment for learning). In the case of the former, the goal of the test is to measure what students know or can do. In the case of the latter, the goal of the test is to provide information that will improve student learning. The third most important issue is, in my opinion, the test / curriculum adjustment. Appropriate assessments measure the objectives set out at the classroom level and at the same time reflect curriculum (or content) that has been selected to reach the specified objectives. To sum up, any decision about a student’s continued education, such as retention, tracking, or graduation, should not be based only on the results of a single test, but should include other relevant and valid information. The classroom is the realm of the teacher. State tests do not tell teachers how to teach, they suggest what should be taught, so there is no reason why students cannot learn how to think critically, solve problems or develop their creativity. State tests are taken at the end of the year or course, so teachers have the opportunity to diagnose their students’ needs and work on their improvement so that by the time they sit for the tests they can feel confident and succeed as expected. It is only fair to use test results in high-stakes decisions when students have had a real opportunity to master the materials upon which the test is based and this cannot be achieved without an active and professional teacher.

Chivalry among men in the novel The Three Musketeers by Alexandre Dumas

The element of chivalry overshadows everything else in Alexandre Dumas's historical romance, The Three Musketeers. The work was set against the background of King Louis VIII's France. It was a time of intrigue, treachery and machinations in high places, an atmosphere in which you could hardly distinguish friend from foe. It was at this juncture that D'Artagnan, the principal character arrives in Paris.When he sets out to seek his fortune in the famed city, as any young man did in those times and still does to some extent, he was armed with only the three things that were given to him by his aging father:They were, a horse as aging as his progenitor, fifteen crowns and a letter of introduction to Monsieur de Treville, captain of the musketeers, the personal guards of the French king. And there follows a story so packed with events that it leaves the readers spellbound.To many, the idea of chivalry seem frivolous, naà ¯ve and very much in vain. It is like taking romanticism to an illo gical conclusion. You have only got to read Don Quixote to remind yourself of this fact. But one comes to the conclusion that there is a flip side to it after all, after reading the swashbuckling heroics of the protagonist and his bosom pals.Although some of their exploits seem somewhat comic and incredulous, the way they were committed endears them to our hearts with the sheer buoyancy, exuberance and spontaneity of those acts. It takes one right back to childhood, when one indulged in the fantasies peculiar to the period, thereby filling us with nostalgia and even dà ©jà   vu.Here, the protagonist also â€Å"Seeks great stature of character by holding to the virtues and duties of a knight, realizing that though the ideals cannot be reached, the quality of striving towards them ennobles the spirit, growing the character from dust towards the heavens.Nobility also has the tendency to influence others, offering a compelling example of what can be done in the service of rightness.à ¢â‚¬  (Price, Brian R. 1997).So the aforementioned negative qualities of chivalry do not in any way detract from the story in the least as we find the protagonist move forward in his onward momentum, in the most chivalrous manner, â€Å"packed with events and exciting dramatic encounters.† (Dumas, Alexandre).For this, indeed, is a story packed with events with the spirit of chivalry leading it ever forward. And watching D’Artagnan move from adventure to mayhem, one is filled with an overwhelming sense of admiration for the perpetrator of all those hair-raising episodes.And before long one is convinced of the fact that the idea of chivalry is not so frivolous and foolish after all, as seemed at first. Although at times it sounds childishly romantic, it has its high points of idealism, even if it is romantic in nature and so not everybody’s cup of tea.For D’Artagnan does follow the kind of chivalry in its original connotations. At every step, he is ‘ guided by the ideals of chivalry, a moral code that has its origins in medieval knighthood.’ (Dumas, Alexandre).And we sit glued to our seats as if are watching an action packed movie. He exhibits almost all the qualities considered necessary by a typical chivalrous person. First and foremost he is guided by the quality of prowess.In every action ‘he seeks excellence in all endeavors he goes through, martial or otherwise. Like a true knight he does not use his strength for personal glory but uses to serve the cause of justice.' (Price, Brian R. 1997).He is also fiercely loyal to the cause and the people whom he seeks to serve. In the novel, he is loyal to his friends, his country and his amour Madame Bonacieux. And like a true knight he fights the forces of evil with all his strength. Thus he battles the villain Cardinal Richelieu and his guards. Yet he has the time to answer the calls of love from the beautiful and enigmatic Madame Bonacieux.His cronies were Athos, Por thos and Aramis. They were with him in all his adventures and escapades throughout the narrative. Strangely enough, they became friends by fighting duels with D’Artagnan on the one hand and the others one after another, on the other.These encounters came to an end when they were confronted by the arch villain Cardinal Richelieu’s guards who, at that juncture and then onwards, became their common enemy. And their common exploits under the leadership of D’Artagnan also became tinted with the codes of chivalry then prevalent throughout the length and breadth of Europe.Another chivalric code of conduct is to fight for justice ‘unencumbered by bias or personal interest.’ ((Price, Brian R. 1997). Accordingly, the four friends wielded the sword in cause of justice while at the same time practicing the fine qualities of mercy and humanity. They fought against the evil Cardinal whose machinations had filled the French court with intrigue, treachery and viole nce.The chivalric code of defense, demands that D’Artagnan and company also should defend their liege lord, in this case the king of France. But here there is a deviation and object the D’Artagnan’s fealty falls on the queen instead of the king by a quirk of circumstance. ‘The Musketeers join forces to protect the honor of the Queen, to help her conceal her affair with Buckingham, and to help her to arrange meetings with him.This may seem like a relatively trivial matter to most modern readers when compared to the urgencies of the political situation of the time, but according to the code of chivalry and honor that the Musketeers believe in, fostering true love is of the highest importance.’In this work the hero achieves his goals through pride honor and determination. A true gallant always defends his honor whatever be the cost of doing so. For this he is ready to die if necessary.

Computerized Management Systems Research Paper Example | Topics and Well Written Essays - 1250 words

Computerized Management Systems - Research Paper Example sharing of information such as lab results and patient information has been well facilitated between medical practitioners, clinics, healthcare providers and pharmacists. This tends to harmonize consultation process that improves the delivery of healthcare. The cumbersome nature of doctors in Emergency room(ER) that operate without computerized systems always delivers (Goldsmith, 2010) dismal performance as they have to work with manual student records. It is through the availability of interoperable tools that clinicians are well able to make sound decisions that improve their chances of saving lives and minimizing suffering. Through computerized management healthcare systems, its interoperability nature is able to provide clinicians with access to updated medical decision support. Furthermore they are capable to provide (Goldsmith, 2010) standard protocols to multiple medical situations. Clinicians and especially doctors will be better placed to select the protocol they find suitable and which can be revised from time to time to improve the standards health care practices. There are many types of computerized health care that can be adopted in any clinical settings. Common to these are electronic medical record systems (EMR). These are systems that provide for a paperless interoperable medical recording system. The present reality of these systems have been greatly favored on grounds of offering quality and cost effective means of handling medical information and data. Secondly we have the electronic healthcare record systems (EHS). This unlike the electronic medical recording systems (EMS), provides a means for which patient records are distributed across several institutions (Frans Turisco, 2008). This furthermore allows for knowledge and decision-support systems that improves quality and safety of patients care across different healthcare sectors. These are just but a few among several computerized healthcare systems that are used in the medical scene

Five network management categories that make up the FCAPS model Essay

Five network management categories that make up the FCAPS model - Essay Example These five functionalities are summed up into a five lettered work FCAPS and this is how they are usually referred to. FCAPS NETWORK MODEL Management Network has coined FCAPS. According to The Computer Desktop Encyclopedia (2011), FCAPS is described as, â€Å"(Fault, Configuration, Accounting, Performance, Security) The ISO framework for network management. If an organization does not bill customers, accounting is replaced with "administration."† Thus, it is the ISO Telecommunications /management Network model for network management. The five heads, each recognized by their starting letter, are The tasks performed by a network model, as interpreted by the ISO and are given the name FCAPS. Their brief description is stated as follows: Fault management The problems being faced by a network and the means and methods by which they are being resolved are referred to as fault management. Fault management detects and highlights any discrepancies hat may occur in the normal functionin g of a network. The resolution of the discrepancies prevents them from reoccurring. This functionality is also a part of fault management. Fault detection is essential for the successful running of a network. The fault detection mechanism of a network usually incorporates the trend analysis strategy. In accordance with it a comparison is made with earlier fault occurrences and their successful resolutions.

Landscape Painting Assignment Example | Topics and Well Written Essays - 250 words

Landscape Painting - Assignment Example Thus romanticism style of art involved exotic, more authentic, familiar and distant modes in harnessing imagination power as portrayed in landscape paintings that were prepared during this period. Romanticism went beyond the confines of population, industrialization unlike it preceding periods, the classical period and medievalism. In fact, romanticism exalted subjectivism, imagination, irrationalism and individualism. The art was highly characterized and influenced by artists’ fascination by their passions, nature, their moods, their mental potentials and the heroes. On the other hand, the Impressionism movement thrived in France between late 1860s and 1890s. This movement was inclined to optical realism since it sought to relate art to visual experience and the effect of light on appearance of various objects. The form of art in impressionism involved transcription of the artists’ visual sensation towards nature, which was unconcerned with the actual depiction of the objects. The main ideas of impressionism were, a quick painting of a landscape could depict it actual physical appearance and that art is promoted by a naà ¯ve vision, free from influence by intellectual preconceptions which were realist traditions and naturalist traditions. In comparison, the romanticism form and style of art applied to landscape paintings is distinguishable from the impression form art employed in landscape painting. This is evident from a keen observation of the following paintings, soleil levant by Claude Monet.

The Fifth Amendment Coursework Example | Topics and Well Written Essays - 750 words

The Fifth Amendment - Coursework Example If the government is not limited in this aspect, it will be easy for them to â€Å"force (coerce) people to answer questions that would cause them to look guilty of a crime† (Harr, Hess, and Orthmann 324). The government's limitations on this matter is even emphasized when â€Å"By the middle of the 18th century, English courts began to limit the admissibility of confessions† (Harr, Hess, and Orthmann 326). This is to prevent the occurrences of â€Å"confessions...obtained by any manner, including force or the threat of force† (Harr, Hess, and Orthmann 326). Not limiting the government's ability to how and when it asks questions opens an avenue for abuse and arbitrary actions. How do you feel about police â€Å"encouraging† suspects to talk by threatening or using physical force or otherwise intimidating them? Despite arguments that the ends can justify the means, one has to keep in mind that regardless of the motivation, individual rights should be, first and foremost, protected, because, personally speaking, it cannot be said that a government can protect the rights of a nation if that government is unable to first protect the rights of the individual. I truly cannot see how justice can be served if the foundation of such â€Å"justice† is already unjust. ... s could mean that if done properly, interrogation techniques can do the job already, so there is really no need to apply force or the threat of force. In the rest of the cases, a more diligent police work --- like searching for physical evidences --- could work in areas where interrogation did not provide much help. Does the Miranda decision impede police work? It is said that â€Å"because of [the] Miranda, substantial numbers of criminal convictions are lost each year† and that it â€Å"may be the single most damaging blow to the nation's crime fighting ability in the past half century† (Harr, Hess, and Orthmann 330). However, it is also said that: Miranda...changed the analysis of the Fifth Amendment protection against self- incrimination from a totality of the circumstances test for voluntariness to whether those subjected to a custodial interrogation by police were advised of their rights...[but] Miranda has not completely displaced the due process/voluntariness st andard. (Harr, Hess, and Orthmann 331) Therefore, the Miranda may have made police work tougher, but it does not absolutely impede police work. This is because â€Å"When a Miranda violation cannot be used to support an attack, voluntariness still can† (Harr, Hess, and Orthmann 331). Would a different result occur, given exactly the same circumstances of an interrogation, for what a private security officer could do as opposed to what a city police officer must do? Private security officers such as security guards or even rent-a-cops â€Å"are not required to advise suspects of their Miranda rights† (Harr, Hess, and Orthmann 360). City police officers are required to issue the Miranda warning to â€Å"individuals they had in custody, before questioning them† (Harr, Hess, and Orthmann 331). This could

Prepare a comparative analysis research paper on people whom you feel Essay

Prepare a comparative analysis research paper on people whom you feel are great business communicators, (e.g. Warren Buffet, Opr - Essay Example As a function of understanding this, the following research will focus upon the means whereby each of these leaders ascribe to the following communications strategies: captivation of listeners by tone and body language and the integration of a tailored/lasered message meant to engage the listener. Due to the fact that it would be foolish and shortsighted to minimize the extent to which key differences play into the process of leadership and communication development, this analysis will include a brief analysis within each of the following sections with regards to how the affected business leaders in question further help to differentiate themselves within such determinants. With respect to the Oprah Winfrey utilizes the first aspect of communication listed above, the observer can quickly note that Oprah herself provides a unique level of interest with regards to the subjects she discusses; acting as a prime motivator for how the shareholder views the product or the situation in quest ion. Rather than merely filling in every space with words, such as many individuals who have received their professional start in talk show hosting are prone to do, Oprah’s ultimate strength is her knowledge of when to allow a sense of effect to develop and when to continue on; when to utilize body language and when not to (Sellers 2002). Similarly, with respect to the second determinant listed above, Oprah exhibits that she understands full well the importance of tailoring and â€Å"lasering† her message to meet the given need within the allotted time frame. This is a skill that many might otherwise overlook; however, it is one of the utmost importance due to the fact that without the ability to target the given shareholder with identifiable and gripping information, no matter how important the subject or how great the need to increase sales might be, the message will doubtless appear flat and otherwise stale (Sweeny 2011). Comparatively, Steve Jobs, during his brief lifetime, utilized the body language as well as verbal imagery to engage shareholders with the excitement and uniqueness of Apple’s product designs. As a means of presenting himself as the sole individual on an otherwise empty stage and methodically yet engagingly discussing these products with both a physical and multimedia audience, Jobs was able to convey a sense of awe and excitement that would likely not have been engaged by a lesser CEO (Gallo 2011). With regards to the second determinant, Steve Jobs seemingly had a type of built-in understanding for the type of language that would grip the consumer and provide them with a sense of awe with regards to the given product. As a function of this, his communication style was not one that wandered from topic to topic during the few brief minutes which he engaged with the public. Rather, there was a direct point, key functionalities, and technical specifications that were related to the would-be user within terms that would no t frighten those that otherwise would not have a great deal of technical expertise or understanding (Cusumano 2011). This primary knowledge of the market with which he was ultimately engaging was the primal reason why Apple has become such a fixture of US technology and engineering that it is today. By realizing what the consumer needed relayed to

Bipolar Disorder Article Example | Topics and Well Written Essays - 250 words

Bipolar Disorder - Article Example The basis of this study is an association between the deregulation of HPA axis and BD diagnosis, present in all clinical cases of BD. A dysfunction of the HPA axis may be caused by an alteration the rate limiting step of cortisol metabolism. A mitochondrial membrane translocator protein (TSPO) is a key regulator in this pathway as it limits the translocation of cholesterol into the power house (Colasanti, Owen, & Grozeva, et al., 2013). An amino acid substitution polymorphism (rs 6971) in the gene encoding for this transporter protein greatly affects the affinity of TSPO to cholesterol. This altered affinity in the defective protein in turn impairs the metabolism of steroids including those of HPA axis. This study provides evidence of association between a single nucleotide polymorphism in the TSPO gene and the diagnosis of bipolar disorder in a large scale case control study (Colasanti, Owen, & Grozeva, et al., 2013). However, the results of this study are suggestive as the findings did not reach genome wise significance; though they were reproducible. This nominal association suggests the possible existence of o ther confounding factors in the etiopathogenesis of bipolar disorder. A limitation of this study is in the use of imputation in the analysis for the rs6971 SNP in the TSPO gene. In conclusion, a bipolar disorder is a mental illness characterized by mood swings. There are several environmental and genetic etiologies to this condition, which can progress to severe forms such as psychosis. A study by Colasanti, Owen, and Grozeva, et al., suggests a possible genetically altered HPA axis function as a causative factor in BD. The genetic mutation in the mitochondrial translocator protein (TSPO) impairs the metabolism of neurosteroids, which in turn alters the HPA axis function (Colasanti, Owen, & Grozeva, et al., 2013). The deregulation in HPA axis has been reported in all BD cases suggesting a

How have public sector spending cuts affected Government outsourcing Essay

How have public sector spending cuts affected Government outsourcing - Essay Example The private sector is currently creating new jobs while the public sector is slashing the workforce. The UK budget deficit is still high despite councils implementing budget cuts in highways maintenance, property service and refuse collection. Most of the government departments are considering outsourcing as a viable method of attaining value-added benefits to the services enjoyed by the citizens (Flynn, 2012). Currently, the UK government outsources more than 80 billion pounds of public sector services and the figure is estimated to reach 140 billion pounds by the year 2015 if the current trend continues. The information technology department is one of the public sector departments that have experienced massive spending cuts. The UK government has axed 95 million UK pounds on IT spending thus leading to high job losses (Flynn, 2012). The UK government has reduced spending on advertising and new contracts with management consultants. The spending cuts are spread in construction, professional services, facilities management department and information and communication technology. The Efficiency and Reform Group is keen on cutting spending cutting the spending on advertising to only the essential advertisements (Flynn, 2012). The media companies such as Trinity Mirror have reported a decline in the value of the shares after the government froze new civil service recruitments. The department of Work and Pensions has made more than 70 million pounds in savings after reducing the spending on IT consultancy and marketing services. The government is also negotiating for cost reductions in the approved IT projects in order to reduce the overall costs of the projects (Flynn, 2012). However, critics of public spending cuts have warned that the current slash on spending will slow down the economic recovery. For instance, Morgan Sindall construction Group warns that reducing the budget on school construction will negatively affect the

How is wells fargo make money Essay Example for Free

How is wells fargo make money Essay Wells Fargo Company is a diversified financial services company providing banking, insurance, investments, mortgage and consumer finance for more than 23 million customers through 6,100 stores, the internet and other distribution channels across North America and elsewhere internationally. Headquartered in San Francisco, but were decentralized so every local Wells Fargo store is a headquarters for satisfying all customers financial needs and helping them succeeds financially. Wells Fargo has $483 billion in assets and 167,000 total team members across 80+ businesses. They are one of the United States top-40 largest private employers; ranked fifth in assets and fourth in market value of stock among their peers as of September 30, 2006 (Wells Fargo’s home page). Wells Fargo’s goal, however, is not to be the biggest, but to be the best. Wells Fargo’s website set forth its vision, which is â€Å"to satisfy all our customers financial needs and help them succeed financially. We want to be recognized as one of Americas great companies and the premier provider of financial services in every one of our markets, number one, second to none. † Loomis (17) states that Wells Fargo’s strategic initiatives include; increase the contribution to banking earnings from investments, trust, brokerage and insurance from 15 percent to 25 percent. Going for â€Å"gr-eight† Increase the number of products their consumer and business customers have with them to eight products per customer. Doing it right for the customer 100% bank-mortgage/home equity cross-sell all mortgage and home equity customers in banking states to bank with Wells Fargo and want all their banking customers who need a mortgage or a home equity loan to get it through Wells Fargo. Wells Fargo cards in every wallet; When, where and how Integrate all delivery channels stores, ATMs, Wells Fargo Phone Banksm, their online banking site, direct mail, interactive video—to match them with when, where and how their customers want to be served. â€Å"Information-based† marketing Use technology to take full advantage; offer the right product to the right customer at the right time at every point of customer contact. Be the customers’ payments processor. Premier customers Attract more and keep all existing premier customers and increase their numbers; and People as a Competitive Advantage- Continue to develop reward and recognize all team members. In 1852 Henry Wells and William Fargo founded Wells, Fargo Co. to serve the West. The new company offered banking (buying gold, and selling paper bank drafts as good as gold) and express (rapid delivery of the gold and anything else valuable). Wells Fargo opened for business in the gold rush port of San Francisco, and soon Wells Fargo’s agents opened offices in the other new cities and mining camps of the West. In the boom and bust economy of the 1850s, According to Hungerford, Wells Fargo earned a reputation of trust by dealing rapidly and responsibly with people’s money. In the 1860s, it earned everlasting fame and its corporate symbol with the grand adventure of the overland stagecoach line (99). Wells Fargo sent its business by the fastest means possible: stagecoach, steamship, railroad, pony rider or telegraph. In 1858, Wells Fargo helped start the Overland Mail Company the famed â€Å"Butterfield Line† to meet the demand for speedy communications across the west. In 1861, Wells Fargo also took over operations of the western leg of the famed, but short-lived, Pony Express (Scheele 250). In 1866, Wells Fargo combined all the major western stage lines. Stagecoaches bearing the name Wells, Fargo Co. rolled over 3,000 miles of territory, from California to Nebraska, and from Colorado into the mining regions of Montana and Idaho. After the completion of the transcontinental railroad in 1869, Wells Fargo increasingly rode the rails. In 1888, after expanding along the new steel network across the Northeast into New York, Wells Fargo became the country’s first nationwide express company. It adopted the motto â€Å"Ocean-to-Ocean† to describe its service that connected over 2,500 communities in 25 states, and â€Å"Over-the-Seas† to highlight its lines linking America’s increasingly global economy. Wells Fargo rushed customers’ business from the urban centers of New York and New Jersey, through the rail hub of Chicago and farming regions of the Midwest, to ranching and mining centers in Texas and Arizona, and to lumber mill towns in the Pacific Northwest. Wells Fargo agents in towns large and small offered basic financial services like money orders, travelers’ checks, and transfer of funds by telegraph. Always, though, wherever there was mining, from Alaska to Arizona, Wells Fargo guarded the gold. By 1910 the Company’s network linked 6,000 locations, including new offices in the Upper Midwest and Great Lakes regions. It was in these towns that the famed â€Å"Wells Fargo Wagon† delivered goods of all sorts, from a grey mackinaw to some grapefruit from Tampa, as the song from the Music Man goes (Hungerford 97). By 1918 Wells Fargo was part of 10,000 communities across the country. That year, however, the federal government took over the nation’s express network as part of its effort in the First World War. Wells Fargo was left with just one bank in San Francisco. Wells Fargo Co’s Bank, San Francisco (as it was called since 1852), formally separated in 1905 from Wells Fargo Co Express. The bank then survived the disaster of the 1906 San Francisco Earthquake and Fire. Bank president I. W. Hellman telegraphed, â€Å"Building Destroyed, Vault Intact, and Credit Unaffected. † From that confident note, Wells Fargo began rebuilding its banking business across the West. In the 1910s and ’20s Wells Fargo served as a commercial bank in San Francisco, supporting the West’s growing business and agriculture, including fledgling auto, aerospace and film industries. The Wells Fargo Stagecoach became a regular actor in Hollywood westerns. Loomis (18) agreed that sound management helped the bank weather the Great Depression, serve the nation during World War II, and positioned the bank to meet new consumer banking needs in the prosperous post-war era. Through the 20th Century Wells Fargo rebuilt from just one office in San Francisco. From 1905 to 1923 it was a premier downtown San Francisco institution. Expanding in 1923 to two marbled banking halls, Wells Fargo was a â€Å"banker’s bank† that served the entire west. In 1960s prosperity, Wells Fargo became a northern California regional bank with branch offices everywhere people lived and played, from the coast to the mountains. In the 1980s Wells Fargo expanded into a state-wide bank and became the seventh largest bank in the nation and launched its online service (Wells Fargo home page). In the 1990s Wells Fargo returned to its historic territory throughout the Western, Midwestern and Eastern states. Today in the 21st Century, with extensive and diversified financial services, the Wells Fargo name once again extends â€Å"Ocean-to-Ocean,† â€Å"Over-the-Seas,† and, of course, On-Line. The famous image of the stagecoach and the reputation of the name saw Wells Fargo well through the mighty events and fantastic growth of the 20th Century. In prosperity, depression and war, even greater post-war prosperity, social changes and ever faster communications technologies, Wells Fargo’s attention to customers’ business has seen it through these great events and brought success. WORK CITED Hungerford, Edward. Wells Fargo: Advancing the American Frontier. New York: Random House, 1949. Loomis, Noel M. Wells Fargo. New York: Clarkson N. Potter, 1968. 17-18. Scheele, Carl H. A Short History of the Mail Service. Washington, DC: Smithsonian Institute Press, 1970. 250. Wells Fargo. Home page. 2006. 23 Nov. 2006 https://www. wellsfargo. com/about/history/adventure/modern_times.

Carbon Membranes from Polyamideimide and Polyetherimide

Carbon Membranes from Polyamideimide and Polyetherimide CARBON MEMBRANES FROM POLYAMIDEIMIDE AND POLYETHERIMIDE FOR NITROGEN AND METHANE SEPARATION AND ITS PARAMETER STUDY ABSTRACT Carbon membranes prepared from polyamideimide and polyetherimide were studied to find out the effects of different parameters on membrane characteristics. Their properties were analyzed to understand its scope in methane purification. Different compositions were tried to find out the optimum polymer composition as well as the optimum blend composition. They were pyrolyzed at various temperatures to study the effect of pyrolysis temperature on the morphology of the membrane. Efforts have been made for obtaining a narrow pore distribution as nitrogen and methane have comparable sizes. Analysis of the microstructure of membranes using XRD confirms the variations in chain packing density and d-spacing of polymer chains as a result of a change in pyrolysis temperature. CHN analysis revealed the percentage composition of different elements in the membrane as it was important to control amount of oxygen in the membrane. Glass transition temperature is found using DSC to confirm perfect blen ding of polymers. TGA has been done to find out how the polymer composition affects degradation temperature and to study the chemical changes occurring during pyrolysis. SEM images, both cross section, and surface have been taken to analyze pore structure of the membrane. Keywords: Polyetherimide, Polyamideimide, Pyrolysis, XRD, SEM, CHN. INTRODUCTION Membranes have been widely received as a promising technology in gas separation processes. This is due to its high reliability, low capital investment and low energy usage which overshadow conventional gas separation techniques such as cryogenic distillation, liquid absorption, pressure swing adsorption etc. These established conventional techniques are known for their complexity in processes and high energy intensity. For this reason, researchers are making efforts for an alternative way that promises to give high-cost effectiveness and easy handling (1). Polymer membranes have been widely studied for their application in gas separating units, but they always faced drawbacks like low thermal and chemical stability. Henceforth studies have been focused on carbon membranes, which are the novel and advanced type of membranes. They have been giving promising results ever since and marked a new benchmark for the selectivity of gasses. Excellent ability to withstand high temperature and chemicals made carbon membranes a new branch of study for the researchers to follow. (2) Carbon membranes are prepared by pyrolysing polymer membranes. Pyrolysis is the most significant step in the preparation of carbon membrane. There are different pyrolysis factors that affect membrane properties. During pyrolysis the parameters like pyrolysis temperature, heating rate, atmospheric condition, soaking time etc. can influence the transport properties of the membrane. These factors are chosen wisely based on the application of the membrane. (3) Material selection is the prime factor concerning in preparation of carbon membrane. There are wide varieties of precursor polymers available for preparation of carbon membrane (4). Selection of polymer is the important factor as pyrolysis of different polymer gives carbon membrane with entirely different properties. The precursor polymer should satisfy minimum criteria such as it should not soften nor liquefies during pyrolysis. It should be able to withstand high temperature (5). Polyamidimides and polyetherimides are being recently studied and are found to be giving satisfactory results due to its high melting point and thermal stability (6). Fuertes and Centeno used polyetherimide to prepare supported carbon membrane for gas separation (7). They conducted gas permeability studies for individual gasses as well as for many mixtures of gasses. They also used phenolic resins for their studies (8). Different polymers are always blended to effectively combine the desirable properties of the blending polymers. Gas separation properties of carbon membranes are enhanced while combining different materials. New studies are going on investigating the blending techniques for an optimized result (9). Pore size control is one of the most challenging factors in carbon membrane preparation. Nitrogen and methane is having a kinetic diameter of 3.6 °A and 3.8 °A respectively (10). So in order to separate them by molecular sieving very narrow pore distribution has to be obtained. To get very specific pore size, pyrolysis temperature was changed accordingly. Two types of polymers were chosen so as to understand the effect of individual polymer on membrane properties. Membrane parameters such as polymer concentration, pyrolysis temperature were varied to understand the morphological as well as chemical changes taking place in the membrane. Comparison of carbon membrane with polymer membrane was carried out, which showed interesting results that can be further used to study gas permeation properties of the membranes. Results revealed that these membranes can be used for the separation process of nitrogen from methane. EXPERIMENTAL Material Polyamideimide (PAI) polymer and Polyetherimide (PEI) polymer which are required for the preparation of polymer membrane were purchased from UTM, Malaysia. N-methyl 2-pyrrolidone (NMP) was the solvent used and it was purchased from Merck Life Science Private Limited, Mumbai, India. Methanol used for washing was bought from Titan Biotech Limited, Rajasthan, India.   Acetone was purchased from Merck Specialities Private Limited, Mumbai, India. All reagents were used without any further purification. Polymer Membrane Preparation Polymers that were chosen for preparation were polyamideimide and polyetherimide. The solvent used was N-Methyl-2- pyrolidone. The polymer concentration in NMP was varied from 2- 20 wt.% as shown in the Table 1. Different batches of polymer solution were prepared by dissolving the corresponding amount of polymer in 25ml NMP. Polyamideimide-polyetherimide ratio in the solution was varied as 25/75%, 50/50%, 75/25%, 0/100% and prepared different batches accordingly. For complete dissolution, the solution was kept for magnetic stirring for 3 hrs. The temperature was increased up to 80oC occasionally for 10 minutes, to avoid undissolved particles in the solution. Later the solution was sonicated in a sonication bath. The solution was then casted on a glass plate using a casting rod. The casting rode that was used has a dimension of 450ÃŽ ¼m. The glass plate was kept in the atmosphere for two days for evaporation of the solvent. Later it was kept inside a vacuum oven at 60oC for complete r emoval of NMP. Table 1: Polymer Batches Sample Code Total Polymer (%) PAI/PEI wt percentage (%) PM-01 2 25/75 PM-02 9 25/75 PM-03 12 25/75 PM-04 15 25/75 PM-05 18 25/75 PM-06 20 25/75 Carbon Membrane Preparation Polymer membrane was cut into a rectangular piece and transferred into an alumina crucible. It was then kept inside a tubular furnace by VBCC   for pyrolysis. It was a horizontal furnace with alumina tube. Nitrogen environment was chosen for pyrolysis. The flow rate of nitrogen was kept at 25ml/min. Polymer membranes with PAI/PEI composition of 25/75% was only further used for making carbon membrane as they showed good structural stability compared to other batches. For pyrolysis different protocols were followed. The protocols are as shown below, 1) 50 to 250 oC at a ramp rate of 13.3 Co/min.(2) 250 oC to (Tmax-15) oC at a ramp rate of 3.85 Co/min.(3) (Tmax-15) oC to Tmax oC at a ramp rate of 0.25 Co/min.(4) Soak at Tmax for 2 h. (11)   After pyrolysis, it was kept for natural cooling before taking out. The different batches of carbon membranes based on different pyrolysis protocol were prepared as given in the Table 2. Polymer membrane with 9% polymer concentration was the membrane used for studying different pyrolysis protocols. Table 2: Carbon Membrane Batches Sample Code Total Polymer (%) Pyrolysis Temperature(oC) CM-01 2 600 CM-600 9 600 CM-450 9 450 CM-800 9 800 CM-03 12 600 CM-04 15 600 CM-05 18 600 CM-06 20 600 Characterization of Synthesized Membranes Various techniques were employed for the characterization of polymer as well as their derivative carbon membranes. Differential Scanning Calorimetry (DSC) was used to find out glass transition temperature of polymer membranes and to study the blending of polymers. Under nitrogen atmosphere, scans from 50 to 450oC at the heating rate of 10oC/min were performed on a DSC Perkin Elmer model 6000. Thermogravimetric analysis (TGA) was used to study the thermal degradation of the polymer membranes. Degradation temperature of the membrane, as well as the weight loss during the process, is analyzed. It was carried out on a TGA Perkin Elmer 4000 model, in nitrogen atmosphere at a flow rate of 30 mL min-1. The temperature range was from 50 up to 750 oC. X-ray Diffractometer (XRD) was used to study the structural changes in membrane due to variation in pyrolysis temperature. Perkin Elmer 1621 wide-angle X-ray diffractometer was the instrument used to study the microstructural changes in membrane. Using Braggs law the average d-spacing of the membrane was evaluated. It is as shown below, nÃŽ » = 2d sin ÃŽ ¸, where n is an integral number, ÃŽ » is the X-ray wavelength, d is for the inter-layer spacing between the polymer chains and ÃŽ ¸ is   the diffraction angle. CHN analysis was conducted to study the variation in the elemental composition with pyrolysis temperature. Elementar Vario EL was the equipment used here for analysis. Compostion of oxygen was found using separate apparatus. Scanning Electron Microscopy (SEM) was used to get pore size of the membrane as well as get a closer image of the membrane. JEOL Model JSM 6390LV is the model used for the analysis. RESULTS AND DISCUSSION Physical properties Both PAI and PEI met the requirements for preparing carbon membrane with promising results. While contents of PAI in membrane made the membrane more brittle, which is due to its aromatic rings, (10) PEI gave structural support to the membrane. So PAI/PEI content was fixed at 25/75% for all the batches later on. As two polymers are used, the miscibility of the precursors has to be tested and glass transition temperature of the membrane was taken as the criteria for the evaluation. For the polymer blends, Tg was found to be in between of that of individual polymers. Tg of PEI and PAI are 217 °C and 280 °C respectively. And from the Table 3 it is clear that both the polymers are completely miscible and was perfectly blended together. Table 3: Glass Transition Temperature Sample Code PAI/PEI wt Percentage (%) Glass Transition Temperature (oC) PM-25 25/75 233 PM-50 50/50 249 PM-75 75/25 265 PM-100 0/100 219 Effect of polymer concentration on thermal characteristics   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Unlike polymer membrane, carbon membrane was thermally and chemically stable. Thermal stability is analyzed by TGA. TGA analysis of all polymer membranes is shown in Figure 1. It shows that concentration does not have much effect on degradation temperature of membranes. But it gives an insight into chose the pyrolysis protocol that has to be followed. There are different pyrolysis protocols for preparation of carbon membranes, based on type of precursors used, one protocol is fixed. Figure 1: Thermal analysis of Polymer Membranes Figure 1 illustrates the weight variation of polymer membranes during the heating process up to 800 °C. According to the TGA thermo-diagram, the degradation temperature (Td) is 550 °C and was defined as the temperature corresponding to 15% weight loss. This indicates the high thermal resistance of the membrane. The total weight loss at 800 °C, with 10 °/min heating rate, was approximately 60%. The enhanced thermal stability of the membrane highlights its quality as a precursor for the preparation of carbon molecular sieve membranes. Effect of polymer concentration on structure of membrane Figure 2: XRD of Carbon Membrane of different concentrations Effect of polymer concentration on structure of carbon membrane is shown in Figure 2. As the concentration of polymer was increased from 2% to 20%, peak intensification took place, resulting in a more compact structure. Pore size was reduced and membrane with higher packing density is formed. Effect of pyrolysis temperature on microstructure of membrane Structural analysis on carbon membranes was done by obtaining XRD spectra as a function of pyrolysis temperature. As shown in Figure 3, the XRD spectrum for membrane prepared at 450oC is a merger of two peaks at 22.7o and 18.8o. With increase in pyrolysis temperature, the peaks joined into a single but intensified peak with a shift toward the smaller pore sizes; indicating a decrement in average d-spacing. Figure 3: XRD of Carbon Membrane prepared at different temperatures d-spacing in carbon membrane refers to interlayer distances, with increase in temperature more compact structures are formed. 800  °C was found to be the optimum pyrolysis temperature as membrane having high density and packing efficiency are formed at this temperature. (1) Effect of pyrolysis temperature on membrane composition In order to study how pyrolysis temperature changed the chemical composition of the membrane, elemental analysis has been conducted for both polymers as well as carbon membrane. In Figure 4, the point zero in x-axis corresponds to precursor membrane and it has the lowest carbon content and they started to increase with increase in pyrolysis temperature. However other elemental contents like oxygen, nitrogen and hydrogen was reduced with increase in temperature. Presence of oxygen compounds in the carbon membrane surface can make the membrane more hydrophilic and can cause swelling of membranes (11). For the better performance of carbon membrane oxygen content has to be less than 4% (12).When pyrolysis temperature in increased, oxygen content is reduced. Membrane prepared at 800oC has oxygen content less than 4%. So the effect of pyrolysis temperature on hydrophilictiy of the carbon membrane was tested to study the influence of oxygen in the membrane. From the Table 4 it is clear that as pyrolysis temperature is increased, amount of water absorbed is decreased, thus increasing the hydrophobic nature of carbon membranes. This can be explained by the reduction in oxygen containing group in membrane with pyrolysis temperature. Figure 4: Elemental analysis of membranes Table 4: Hydrophilicity of carbon membranes Sample-Code Pyrolysis Temperature ( °C) Wet weight of the membrane (g) Dry weight of the membrane (g) Amount of water absorbed (g) CM-450 450 0.0588 0.0553 0.0035 CM-600 600 0.0523 0.0503 0.0020 CM-800 800 0.0687 0.0607 0.0008 Morphology of Membranes The surface and cross-section morphologies of carbon membranes as well as polymer membranes were investigated by SEM (Scanning Electron Microscopy) techniques. Surface image of polymer membrane is shown in Figure 6. It shows a smooth and defect free surface without any deformation. Cross section of the polymer membrane is also shown below. Compared to carbon membrane it does not have uniform pore distribution. All the pores are elongated pores and the membrane formed is very dense. Thickness of polymer membrane was found to be 250ÃŽ ¼m. The honey-comb structure of carbon membrane shows the pore structure in the membrane (Figure 5). It is clear from the image that the membrane is rich in pores and has quite a uniform pore distribution. The membrane was having a sponge-like matrix unlike polymer membrane. This uniform pore distribution allows carbon membrane to have high selectivity over polymer membrane.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   (b) Figure 5: SEM images: (a) Top surface and (b) Cross section of Carbon Membrane   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   (b) Figure 6: SEM images: (a) Top surface and (b) Cross section of PolymerMembrane CONCLUSION Different polymer blends were tried for the preparation of polymer membrane and membranes derived from Polyamideimde/Polyetherimide (25/75wt.%) exhibited more attractive performance than the other blends. Polymer concentration was varied from 2-20% and at 9%   it was found to be exhibiting best results. Polymer membranes prepared from PAI/PEI were transparent hydrophilic membranes. Polymer membranes were thermally unstable compared to carbon membrane and were found to have degradation temperature around 450oC. Complete miscibility of both the polymers was confirmed and the glass transition temperature of the polymer membrane was also found. For the preparation of carbon membrane different protocols were followed for pyrolysis, and 800oC was found to be the optimum temperature for pyrolysis. Thermal analysis of membrane had conducted, which proved the higher thermal stability of the carbon membrane. Morphological studies shows that carbon membrane prepared at 800oC have desirable pore size compared to other membranes prepared at lower temperatures. XRD studies of the carbon membrane showed that as temperature increases, more compact membranes are obtained, which decreases the permeability of the membrane. All the membranes have shown promising results that can be further investigated for gas separation studies. References 1. Carbon membranes from blends of PBI and polyimides for N2/CH4 and CO2/CH4. Seyed Saeid Hosseini, Tai Shung Chung. s.l. : Journal of Membrane Science, 2009, Vol. 328. 174-185. 2. A review on the latest development of carbon membranes for gas separation. A.F. Ismail, L.I.B. David. s.l. : J. Membr. Sci., 2001, Vol. 193. 1. 3. Fabrication of carbon membranes for gas separationa review. S.M. Saufi, A.F. Ismail. s.l. : Carbon, 2004, Vol. 42. 241-259. 4. Gas permeation through micropores of carbon molecular sieve membranes derived from kapton polyimide. Suda H, Haraya K. s.l. : Chem B, 1997, Vol. 101. 3988-94. 5. DH, Morthon-Jones. Polymer processing. London : Chapman and Hal, 1984. Chapter 2. 6. Relationship between chemical structure of aromatic polyimides and gas permeation properties of their carbon molecular sieve membranes. H.B. Park, Y.K. Kim, J.M. Lee, S.Y. Lee, Y.M. Lee. s.l. : J. Membr. Sci., 2004, Vol. 229. 117. 7. Carbon molecular sieve membranes from polyetherimide. Fuertes AB, Centeno TA. s.l. : Microporous Mesoporous Mater, 1998, Vol. 26. 23-6. 8. Supported carbon molecular sieve membranes based on phenolic resin. Centeno TA, Fuertes AB. s.l. : J Membr Sci, 1999, Vol. 160. 201-211. 9. Gas separation properties of carbon molecular sieve membranes derived from polyimide/polyvinylpyrrolidone blends: effect of the molecular weight of polyvinylpyrrolidone. Y.K. Kim, H.B. Park, Y.M. Lee. s.l. : of the molecular weight of polyvinylpyrrolidone, 2005, Vol. 251. 159. 10. Ahmad Fauzi Ismail, Dipak Rana, Takeshi Matsuura ,Henry C. Foley. Carbon-based Membranes for Separation Processes. London : Springer, 2011. 11. Carbon molecular sieve membranes derived from Matrimid polyimide for nitrogen/methane separation. Xue Ning, William J. Koros. s.l. : Carbon, 2014, Vol. 66. 5 1 1 5 2 2. 12. Interaction, miscibility and phase. E. Fà ¶ldes, E. Fekete, F.E. Karasz, B. Pukà ¡nszky. s.l. : Polymer, 2000, Vol. 41. 975. 13. Gas permeation and micropore structure of carbon molecular sieving membranes modified by oxidation. Kusakabe K, Yamamoto M, Morooka S. s.l. : J Membr Sci , 1998, Vol. 149. 59-67. 14. Characterization of ultramicroporous carbon membranes with. Jones CW, Koros WJ. s.l. : Ind Eng Chem Res, 1995, Vol. 34. 158-163.