Ultrafiltration Process :: ultrafiltration nanofibrous membranes

What exactly do we mean by Ultrafiltration, and for what processes can it be used? Ultrafiltration is a process by which one uses a pressure-driven process utilizing a specific-sized membrane to separate macromolecular weights of a solution, allowing the transfer of the low molecular weight (permeate). Ultrafiltration is exclusively defined by the pore size range (0.1 – 0.001 microns) (Dhawan). Ultrafiltration is used in a wide array of applications, such as food and beverage, chemical, pharmaceutical, medical, drinking water, wastewater and etc. This research review will focus on industrial applications, and transport processes that make ultrafiltration unique, as well as the industry standard for separation. The rapid development of ultrafiltration for industrial processes is possible by the advent of anisotropic, high-flux membranes capable of distinguishing among molecular sizes of 10 A to 10  µ size ranges (Porter, 1972). The high molecular solute which flows through, but does not pass through the membrane is released as retentate (concentrate). The solution that passes through the membrane is known as permeate, which is shown Figure 1. This figure demonstrates the basic structure of a hollow membrane where the feed of the material you want to separate enters, and where the permeate (ultrafiltrate), and retentate exits. In different industrial processes one may want to retain the permeate, retentate, or combination of both. Mass Balance, Momentum Balance and Flux Figure 1: Flows and fluxes in a hollow fiber for ultrafiltration (Yeh, 2009) Let us take a closer look at what drives ultrafiltration from a mathematical point of view. In Figure 1, the feed solution is being driven by a volumetric flow rate (qi/Ni), pressure (∆Pi), and concentration (Ci). This feed solution produces a mass balance which results in the flux (J) vs fiber (dz): (Yeh, 2009) The momentum balance must be accounted for also: (Yeh, 2009) It can be presumed that the volumetric flow rate will be reduced similarly to the Hagen–Poiseuille equation, due to the laminar flow within the tube in Yeh, H. experiment in 2009, he takes into account convection as well as mass, and momentum balance: (Yeh, 2009) Equation 3 assumes that the volumetric flow rate is relatively large compared to that of the permeation rate. This occurs mainly in an exponential model along the membrane tube. This model simply states that when working with a pressure-drive ultrafiltration process, as pressure is increased, a ceiling (limiting) flux will occur regardless of increasing the pressure. We know that the relationship between membrane pressure (∆Ï ) and the permeate flux leads us to the following conclusion (Yeh, 2009).

Commentary on Turning point in Othello

The passage in Act 3, Scene III of Shakespeare's Othello, where Othello cracks down on Iago and demands proof from him of Desdemona's unfaithfulness, is the turning point of the play. Iago has Othello in the palm of his hand, and has Othello's entire fate planned out. He has done this by making him think that Desdemona is cheating on him with Cassio. In this scene, Shakespeare employs the use of three literary devices to construct the scene as a turning point and push the play forward. Firstly, the use of metaphors are essentially to provide the atmosphere of the scene. Then, Shakespeare uses dramatic irony to foreshadow what Iago is going to do. Finally, the setting is used to position and set up the scene as the turning point where Othello's tragic flaw will be exposed. All of this helps to achieve the purpose of showing how this is the turning point in the play. The first literary device used is vile metaphors. Othello, who is the one who talks the most during this passage and uses very contemptible language, which is quite different to how people talk before this point. Othello's harsh language serves to heighten the tension in the atmosphere. In addition, it demonstrates the decay of Othello's character by the theme of jealousy and its power. The first place in the passage where Othello demonstrates this is near the beginning of the passage by saying, â€Å"Thou hast set me on the rack. † Othello's metaphor between his torture and medieval torture shows not only the seriousness of the situation, but that his character would refer to such heinous instruments. Furthermore, Othello blatantly threatens Iago when he says, â€Å"Thou hadst been better have been born a dog/ Than answer my waked wrath! This language would be unbecoming of a gentleman, during Shakespeare's time, thus it demonstrates that Othello's character has degraded completely because of the jealousy planted by Iago. The second literary device used by Shakespeare is that of dramatic irony. However, it is in its most extreme form. This is shown in the passage when Othello tells Iago, â€Å"Villain, be sure thou prove my love a whore! / Be sure of it. G ive me the ocular proof. † Here Othello is demanding Iago to prove that Desdemona unfaithful with visual evidence. The ocular proof is Othello's entire basis for killing Desdemona, and the proof is coming from Iago, thus putting him in control of Othello's fate. The handkerchief is the ocular proof that Iago produces in order prove Desdemona a cheater and a liar. This makes the passage a turning point in the play when Iago gains total control over Othello, while Othello doesn't realize he's being played, and will only after the plan is complete. Finally, the third literary device used is setting. The passage is in the middle of Act 3, which would place it close or right on top of the climax, for a standard 5-part play. At the beginning of the scene, Cassio was talking to Desdemona about getting reinstated, and with Iago's help Othello misinterprets it and thinks that Cassio is sneaking around behind his back. This shows that Iago has started to mold Othello into a jealous monster that will eventually lead to his downfall. This scene is the turning point because Iago has had the opportunity to have Othello see Cassio in Othello's bedroom, talking to Othello's wife, while whispering like a snake to him, that perhaps there's something more between Desdemona and Cassio than meets the eye. In conclusion, these three literary devices, metaphors, dramatic irony, and setting allow the scene to ascertain itself as being the turning point of the play. Othello has the seeds of jealousy planted within him now, and Iago is gulling both Othello and Roderigo. The effect on the audience is that they feel Othello's emotions and can see the complete degradation of Othello's character, allowing the audience to get in the mood for the downfall of Othello.

Product Analysis on Gillettes’s Razors

Gillette is leading worldwide home applicants, such as razor, battery, electronic and manual toothbrush, manufacturing company. On April 14, 1998, the company introduced the world†s first triple blades razor and begun to sell July 1, 1998 in the United States and September in the Western Europe. Since Gillette launched new razor in 1998, the company expected high returns in short-term; however, the result of the new product has been defined yet. The areas of the internal factors are Finance, Management, Manufacturing, Market position, Personnel, and Research & Development. All these factors can be defined as either strengths or weakness or both. First of all, the company as a whole gained net sales amount of 10. 1 billion dollars and net income of 1. 4 billion dollars for the 1997 due to acquire leading battery company â€Å"Duracel† in 1996 and grow of â€Å"Sensor Excel† razor. As a result, company could spend 1 billion dollars to invent â€Å"Mach 3† which is triple blades razor. Even though Gillette had sufficient fund to invent the new product, the company took high risk of financial side that if the new product†s sale does not reach to company†s expectation, the company will face shortage of capital resources and can be lead to bankruptcy. But if Mach3 turn out to be a New Coke or McDonald†s Arch Deluxe – much-hyped new products that were mostly duds and fizzle- the gloom will be heavy from Gillette†s corporate headquarters in Boston†s Back Bay to the South Boston factory that Gillette has overhauled to produce 600 million Mach3 blade cartridges per year, or about half of Gillette†s annual target of 1. billion Mach3 blades. (Boston Globe, 4/15/98) Since Gillette introduced â€Å"Mach3† in April, the company changed its manufacturing tools to produce Mach3 South Boston's factory. Gillette already spent 300 million dollars for advertising and promotion worldwide for the year that company introduced new product. The amount is twice as much as the company put for advertising â€Å"Sensor Excel† in 1989. Gillette released the new product to retail stores on July 1, 1998, and starts to advertise on TV and the other media six weeks later; however, many people went to the company's web site to look at the new product. Even though company spent tremendous amount of fund for the advertising, some people from Asia did not recognize the product according to our group's survey. For customers, there are satisfaction and complaints for Mach3. People, who satisfied with Mach3 according to our survey, said there are less irritation and faster shaving time. Customers who complaint about Mach3 argue that they do not want to spend more money on better outlook. According to our survey, one hundred percent of surveyees, who does not satisfy with Mach3, say the price is too high for the product. Price is relatively higher than other products including â€Å"Sensor Excel† which was the most expensive one before â€Å"Mach3†³ came out. Its price is 6. 99 dollars per razor with one blade included – currently, the company is selling for 7. 29 dollars per Mach3. It is 4 percents increased from original price, and 40 percents higher price than other products. This may lead to decrease in sales and the company†s total revenue. The company is trying to reach customers several different ways. Gillette offers Mach3 package product, which included Mach3 itself and couple of extra razors, Shaving cream and deodorant. This package product makes each items† unit price lower than sell separately. Also, the company offers sweepstakes on the company's web site, and there is no obligation. This is the one of the finest ways to reach and get involve the customers. The company give chance to people to win prize without any obligation; however, people will recognize the product automatically. Also, Gillette can acquire the Since Gillette is well-known global company, many retail stores are not offended to carry the company's product even though the product's price is high. Retail stores are assume that Mach3 will bring more customers. On the other hand, even more customers come to store, it is unpredictable for increasing store†s sales revenue because price is too high so that consumers would not buy. External factors are Competitive, Economic, and Social. Gillette†s major rival in the market is Shick. Since Gillette is the first company produce triple blades razor, the company will lead the market; however, rival company such as Shick will develop the same product with higher quality or lower price. Then the result will be unforeseen unless Gillette improve Mach3†³s weakness – â€Å"high price†. For long time in the United States, people†s income has been growing. As a result, customers purchasing power also increased. However, the company†s market is not only the United States but also overseas, in fact, over sixty percents of sales are made from overseas. Consequently, the company has to consider the facts that poor countries† consumers are willing to use cheaper product; especially the countries in economic crisis. There are 3 target groups in the market. The first group is disposal razor users that it's approximately more than half of the market. The advantages of this group are cleaner, cheaper and easy to use. On the other hand, it is less quality than other two razors. The second group is regular razor such as Mach3 about 40 percents. The last group is electronic shaver users which it takes remaining market share. The customers who use the electronic shaver satisfied with high technology, easy to use, saving time and safety compare to the other two products. The disadvantages of this product are high price and less cleanness when one shaves. The goal of Gillette is trying to acquire customers who use disposal and electronic shaver to Mach3. In order to persuade the customers to change to Mach3, the company should beat other product's weaknesses and add the improved the weakness of the other product to Mach3 and decreases of its weakness. Mach3 has several strengths; the first impression is fancy outlook that makes customers feel differentiated from other products. Second of all, men are challengers, always pursue new trend; especially on the tangible items with high technology. Although Mach3 has several strengths, it also has weaknesses. High price makes people think twice to purchase Mach3; the older generation of the Gillette razor is cheaper than Mach3, that makes people wonder if it is necessary to spend more money on the Mach3. The key purpose for Mach3 is to shave beard, but the older generation is also doing same job as Mach3; that makes no different between older and newer product. The next weakness is the advertisement. Gillette has spent 300 million dollars on the advertisement, but we did the survey with at least thirty people; 22 out of 30 surveyees know the brand from Television and magazine, but they have never uses it. This means the advertisement has preached the good news, but it has not reach people's life. The majority of men do not know why they should spend more money to buy same result. The marketing strategy did not fail the sale of the Mach3, it is price controller. The main point of the marketing is to opening a market for product. Since 73% of the men from the survey know the product, this mean the marketing strategy succeed its intention. The biggest mistake we found is the price. As I mentioned, â€Å"the majority of men do not know why they should spend more money to buy same result†. I would recommend to the company, to lower the price and match the same price as older generation. Let public buys Mach3 as the same price as older generation, allow public to try out differences between Mach3 and older generation. After when market demand of the Mach3 is higher than older generation, then increases its price.

The Things They Carried Book Report

The Things They Carried Book Report Free Online Research Papers I read a book called â€Å"The Things They Carried† by a man named Tim O’Brien. In this book O’Brien wanted to show his readers about his past war times and what him and his platoon had to endure day after day. He wanted the readers to understand that war is much different than just being out killing people. His main goal was to express the hardship he endured and the guilt he receives even after doing something right. In the book O’Brien would explain how everyday he would have to carry his weapon, Pictures of family, water, food, medical supplies, knives and many other things. Not only would he and his platoon have to carry all of their equipment, but also they would have to walk miles on end while they carry it. His platoon changed their schedule to avoid detection. They would move only at night and during the day rest. When someone goes to war its not all about ‘go over there and kill everyone so we can win’. Our troops kill only if their life is in danger. After each kill the soldier has to endure guilt. Not all soldiers are like that. Some change as O’Brien explains in this book. After a soldier kills a few he becomes immune to the guilt and treats the dead just as if they were alive. O’Brien explains that all the men in his platoon would go to the dead and shake their hand and talk to them. He was new to this whole war thing at the time and was disgusted in seeing them treat the men/women with such disrespect. A soldier’s job is to obey his commands, to protect himself and his country; if the only way he can accomplish that is to kill he will. Killing to survive and save others lives in our world’s eyes is right but to a soldier its way different. It’s different because the kill is on his back and not ours. He will never be able to forget his first kill. His whole life he will have to live with this false guilt. This is why we need to support our troops. Research Papers on "The Things They Carried" Book ReportCapital PunishmentHarry Potter and the Deathly Hallows EssayThe Hockey GameArguments for Physician-Assisted Suicide (PAS)Book Review on The Autobiography of Malcolm XTrailblazing by Eric AndersonEffects of Television Violence on Children19 Century Society: A Deeply Divided EraGenetic EngineeringQuebec and Canada

Feast Symbolism in the Odyssey Essays

Feast Symbolism in the Odyssey Essays Feast Symbolism in the Odyssey Paper Feast Symbolism in the Odyssey Paper Essay Topic: The Odyssey Symbolism in Book III and IV Odyssey One of the noticeable symbols in these two books is the presence of food gatherings and feasts. Organized celebrations are a part of social culture during ancient times. The motives of celebrations are usually various, weddings, triumph and returns from wars. Gertrude Jobes (Dictionary of Mythology, Folklore and Symbolism) describes feast as anything affording enjoyment to the body or spirit, special festivities were organized for the poor people, sometimes the guests were taken care of in a peculiar way, washed, perfumed, amused by story-telling. A general definition of a feast is a banquet of a more or less public nature, an elaborate and abundant repast, especially one commemorating some event or person (1961). Banquets often show the wealth of the family by the catering and the amount of food offered. Offering luxurious food, and entertainment by poets and musicians ensures good reputation among the province. Throwing a feast for a guest is a common role of hospitality, and a method to please the guests. However in the Odyssey hunger and the consumption of luxury food connotes a negative association. These represent lack of discipline or submission to temptation. Hungry men that travel with Odysseus are constantly tested their resistance of falling into the temptation, and the willing of escape. In Book III, the suitors, are continuously eating. These banquets help the reader emphasis on the human relationships, union of people, sharing of food passing the gold cup with wine and themes such as love, hate, religion, war, disloyalty, etc. :

Introduction to the Dirac Delta Function

Introduction to the Dirac Delta Function The Dirac delta function is the name given to a mathematical structure that is intended to represent an idealized point object, such as a point mass or point charge. It has broad applications within quantum mechanics and the rest of quantum physics, as it is usually used within the quantum wavefunction. The delta function is represented with the Greek lowercase symbol delta, written as a function: ÃŽ ´(x). How the Delta Function Works This representation is achieved by defining the Dirac delta function so that it has a value of 0 everywhere except at the input value of 0. At that point, it represents a spike that is infinitely high.  The integral taken over the entire line is equal to 1. If youve studied calculus, youve likely run into this phenomenon before. Keep in mind that this is a concept that is normally introduced to students after years of college-level study in theoretical physics. In other words, the results are the following for the most basic delta function ÃŽ ´(x), with a one-dimensional variable x, for some random input values: ÃŽ ´(5) 0ÃŽ ´(-20) 0ÃŽ ´(38.4) 0ÃŽ ´(-12.2) 0ÃŽ ´(0.11) 0ÃŽ ´(0) ∞ You can scale the function up by multiplying it by a constant. Under the rules of calculus, multiplying by a constant value will also increase the value of the integral by that constant factor. Since the integral of ÃŽ ´(x) across all real numbers is 1, then multiplying it by a constant of would have a new integral equal to that constant. So, for example, 27ÃŽ ´(x) has an integral across all real numbers of 27. Another useful thing to consider is that since the function has a non-zero value only for an input of 0, then if youre looking at a coordinate grid where your point isnt lined up right at 0, this can be represented with an expression inside the function input. So if you want to represent the idea that the particle is at a position x 5, then you would write the Dirac delta function as ÃŽ ´(x - 5) ∞ [since ÃŽ ´(5 - 5) ∞].   If you then want to use this function to represent a series of point particles within a quantum system, you can do it by adding together various dirac delta functions. For a concrete example, a function with points at x 5 and x 8 could be represented as ÃŽ ´(x - 5) ÃŽ ´(x - 8). If you then took an integral of this function over all numbers, you would get an integral that represents real numbers, even though the functions are 0 at all locations other than the two where there are points. This concept can then be expanded to represent a space with two or three dimensions (instead of the one-dimensional case I used in my examples). This is an admittedly-brief introduction to a very complex topic. The key thing to realize about it is that the Dirac delta function basically exists for the sole purpose of making the integration of the function make sense. When there is no integral taking place, the presence of the Dirac delta function isnt particularly helpful. But in physics, when you are dealing with going from a region with no particles that suddenly exist at only one point, its quite helpful. Source of the Delta Function In his 1930 book, Principles of Quantum Mechanics, English theoretical physicist Paul Dirac laid out the key elements of quantum mechanics, including the bra-ket notation and also his Dirac delta function. These became standard concepts in the field of quantum mechanics within the Schrodinger equation.

Team Work Essay Example | Topics and Well Written Essays - 750 words

Team Work - Essay Example The Belbin theory of team building states that in order to build a good team, a workplace should be assessed in great detail to look at the strength and weaknesses of individuals. The information learned at this stage can be used in selecting the right people for the right task. It will help in building good working relationship because people with the right skills will be doing the right tasks and hence will enjoy success and authority over what they do and this will in turn make them more confident and will help them achieve their targets with ease. It will also help the development of high performing teams because right people will be doing the right work. This will create positive synergies and generated output will greater than the sum of inputs by the team. It will also help build mutual trust and understanding because all the team members will know that right people are doing the right job and hence it will be easier for all team members to communicate, report any blunders and take the corrective action as a team if necessary. All of this will build a winning team which will work extremely efficiently in congregation to achieve their tasks, goals and target within the given span of time. Belbin also gave a clear definition of team members. He believed that personality hardly matters in team setting. An individual should be judged by the way he behave, contributes and interrelates with the other team members and sees them as his peer. Team working can help team members in working in the field in which they are strong in and eliminating their weak aspects by assigning some of the tasks to people who are good at one of the team member’s weakness. In other words, team work is a congregation of strengths and elimination of weaknesses. Everyone in a team can focus on the core competencies while letting other team members do the task in which one is weak in. This is an impressive utilization of the congregational strengths that a team has. It leads the t eam to be more efficient, productive and time efficient. As a result, many of the large organizations divide their work in projects to be completed by competent team of individuals having varied skills sets and way of think. This eliminates the problem of being stuck in tasks and all the work flows smoothly which benefits the entire organization. During research done on the topic, it was found that balance is the key in the success of a team and individual’s that are part of a team. Too much of one kind of skills may lead to a team that may not be able to operate as efficiently as a team that has varied skill sets. Hence, all kinds of skills should be given a weightage when composing a ideal team. This weightage should then be compared with the skills required in a job and team composition should not be complete until and unless the two are not in equilibrium or the sum of skills sets required in a job and sum of skill sets of a team are equal. Only then an ideal team will be formed, when both are in equality. Belbin allowed certain types of weaknesses in a team. These include people who are forgetful, people who delegate too much work leaving too little for them, people who are slow, perfectionists, bad-humored and specialist in their old fields. All of these weaknesses are accepted because there is no incompatibility in the team’s targets and all of these weaknesses are personality based and not work based. Hence, Belbin believes that these types of weaknesses in a team setting are allowable and does not make much difference as compared to work related weaknesses. The personal example that I would like to share through this essay is when I was completing a research work in a group. I encountered people of diverse personality