How personal and societal values Essay

(How personal and societal values can influence ethical decision-making) Nurses may be faced with ethical conflicts. As nurses we must examine our own beliefs and feelings regarding ethical issues and not impose our own values on any patient or caregiver. At the same time, it is our duty to also support appropriate behavior and to protect our patients from harm. Ethical issues involve the good and bad of moral duty and moral obligations. Nursing can be considered an ethical nterprise since it often involves an alternative action when providing care (Gilliland, 2010). It concerns doing well and avoiding harm. The nursing code of ethics is a great resource to follow when faced with ethical dilemmas. In the Marianne case study, it states that â€Å"she has no advance directives, but her husband wants to try everything† and the children believe that Marianne â€Å"would not want to undergo surgery only to be kept alive with poor quality of life. † An advice that nurse may give to Marianne’s family is to help them be aware of the result of the medical procedures. Marianne’s husband needs to know that once she undergoes surgery there is a good chance that they will need to have some lifestyle changes. As nurses, we should be able to provide the family with an objective view of the importance of each action as well as provide some emotional support that Marianne’s family need to deal with to their current situation. In the second case, with Nurse Jane having witnessed acts of negligence from her olleague, there may be things to consider that might make Nurse Jane’s decision.

DICOM VS Captiva Case Study Essay

1. What are the key business success factors and risks for DICOM and Captiva? DICOM is a Swiss company that has sales in Europe, Asia, and the United States. They provide services ranging from structured, semi-structured, and unstructured information capture products. DICOM also sells hardware, primarily scanners, through its group sales force. DICOM has differentiated their product offering for the different regions that it operates. And the products that are provided are developed through research and development and also acquisitions. This allows DICOM to provide a diverse set of products that can cover many markets and many different users. DICOM operates in the U.S. under Kofax capture software that was bought in 2004 and primarily offers the information capture software’s to their consumers. There are risks in this industry. DICOM operates in many different markets and is subject to inflation, interest, and foreign currency risks. DICOM operates in three different geographic segments that are managed independently of each other. Each market has their own inherent risks and DICOM needs to be aware of every possible circumstance in order to remain prosperous. Captiva Corporation is a U.S. based company that provides similar services as DICOM. Captiva sells structure, semi-structured, and unstructured information capture products, but also sells hardware. Captiva uses its own research and development, as well as strategic acquisitions to provide customers with the different types of information capture products. Captiva sells primarily in the United States, but is able to sell in the areas of insurance, financial services, technology, government, and manufacturing. Involvement in so many distinct markets allows Captiva to hedge their risks better against harsh economic times and different interest rate risks. Additionally, Captiva has a large chain of resellers, which accounts for nearly 39% of revenues. Future profits will best be achieved by leveraging to existing customer base, increase reseller sales, moving into new markets, and broadening the product offering. But like DICOM, Captiva has business risks that they need to be aware of in their industry. Captiva has 80% of their sales in the United and States and cannot hedge their risks if a crisis develops in that country. Captiva has a large amount of revenues coming from resellers and a drop in this segment could lose the company millions. 2. Do the financial statements for the two firms enable you to compare their performance? If not, what changes need to be made to ensure comparability? The financial statements are for two different governmental requirements from two different countries. DICOM operates under the European system of IFRS and Captiva operates under GAAP. With this said, just looking at the financial statements makes it extremely difficult to determine performance. To be able to make a comparison between the two companies easier, their needs to be a reconciliation of the two different accounting systems. IFRS and GAAP need to be put together to form one individual accounting entity. What exactly need to be changed are the standards. When looking at the balance sheet, you are able to see just how different the systems operate. In GAAP, cash is the first line, but in IFRS Fixed assets are the first line. Changing to a consolidated system would allow for the best way to make an accurate comparison between t wo firms in different geographical regions. 3. What financial ratios would you use to judge performance of DICOM and Captiva? How do they compare on these dimensions? The financial ratio used to give us a better assessment of performance is return on equity. Return on equity is the amount of income earned from shareholder investments. And this gives us a look at how much money a company is able to generate from their shareholders. Return on equity is profit margin X asset turnover X financial leverage. The table below shows the ROE for the two companies in the periods of 2003 and 2004. As we can tell from the chart, Captiva earns more money per dollar of shareholder investment than DICOM. To further get a better understanding of the companies, we can use financial, liquidity, and debt ratios to measure performance. DICOM has a better return on assets than Captiva, but not by much. So, we can determine that they both are similar in this area. Captiva has higher gross margins and lower debt than DICOM. So, it is predictable that Captiva has access to money faster and can leverage this pool of resources to invest in R&D and acquiring new companies. 4. Which company do you rate as the better investment? WHY? Both companies are in a fast paced, technology based industry. Before investing, you need to do the proper due diligence into all functions of the business before investing. In this case, it is decided that we would invest in Captiva. Captiva is a U.S. based company that is diversified into many different sectors. They sell to government, insurance, technology, and manufacturing. This would help them hedge against economic risks. Captiva is also not as affected by inflation, currency, and interest rate risk as DICOM. Captiva also is currently providing a higher return on equity on their investments. This shows that the money that is provided is being used efficiently. Captiva seems to be doing well in the U.S. domestic market and has a secondary reseller section that provides stability and consistent revenues. Captiva seems to be the company that can provide the growth and sufficient returns on investments that we are currently look for.

My Father's Suitcase by orhan pamuk Research Paper

My Father's Suitcase by orhan pamuk - Research Paper Example His father said, â€Å"Just take a look,† slightly embarrassed. â€Å"See if there’s anything in there that you can use. Maybe after I’m gone you can make a selection and publish it† (Pamuk). At that time, Pamuk did not understand the gravity of the situation because he never understood that his father meant death. His story however unfolds as he opens the suitcase to find excellent pieces of writing and literature, something that made him think about his father from a different perspective altogether, something that made him the great writer and man that he is today. Pamuk talks about the characteristics of a writer by incorporating the way his father was; by reading the letters and papers that his father had left behind for him, he forms a different worldview about him. He begins to understand that his father did not take up his writing in order to help the family live a substantial life because his grandfather had been a wealthy businessman and thus Pamuk’s father did not want to disappoint the family by becoming a writer and taking the risk of not being able to earn enough money. He thus kept this personality of his a secret from the rest of the world, and was too scared to display it before he was gone. He was perhaps embarrassed because of the fact that he would have turned out to be a wonderful writer and that he would later feel regret in his life for not having taken up that path when he had the chance. He thus opted for the path of least resistance, the path where he showed his son what kind of a man he actually was, what his inh erent personality revealed about him, and how he could make a difference in his son’s life by showing him all of that. Pamuk writes, â€Å"The lovely Turkish expression â€Å"to dig a well with a needle† seems to me to have been invented with writers in mind. In the old stories, I love the patience of Ferhat, who digs through mountains for his love – and I

Tea and L-Theanine Essay Example | Topics and Well Written Essays - 250 words

Tea and L-Theanine - Essay Example Theanine competitively restrains the transmission of glutamate into tumor cells. This leads to a fall in the levels of intracellular glutathione (GSH). It also hinders chemotherapeutic agents’ influx restricting them to tumor cells (Thorne Research Inc., 2005). Through its antioxidant capability, theanine also safeguards to normal cells from damage by chemotherapeutic agents. Studies have indicated that L-theanine has the ability to neutralize caffeine’s stimulatory effect. Further, L-theanine has been linked with LDL cholesterol oxidation (Thorne Research Inc., 2005). Green tea is an antioxidant and has a calming effect on users. Passionflower tea relieves tension in the muscles and has a relaxation effects on nerves. Hops alleviate nervousness and stress. Kava relieves people from anxiety and stress. Lemon balm reduces anxiety and boosts mood. Chamomile has a relaxation effect on users. Catnip is a mild stimulant that reduces tension in the muscles. Blue vervain pacifies the nervous system. Lastly, valerian is a sedative, reduces muscle tension and ensures good sleep (Miller, 2013). Therefore, tea is a good stress reliever because of its relaxation

Popular culture 6 Assignment Example | Topics and Well Written Essays - 500 words

Popular culture 6 - Assignment Example In comparison to other generations, it is more heterogeneous, embraces social diversity in terms of race, class religion ethnicity and sexual orientation. The evolution and film and video during this generation took a different dimension. It was the time when music video spread to all cultures. Generation x is made for the TV film which was first aired on Fox in 1996. It is farther based on the marvel comic which was produced by the new world entertainment. The x men are a television movie about the generation of x comic. It was one but longer considered. It was bunch of teenagers who were blessed or cursed with superhuman power. They would attend school where the teacher’s morality is questionable. In addition to video, this generation also started music video in which one could sing be displayed. This generation shares some things in common with film and video the area chosen. The element of dictatorship in the school in the video which characterized this generation was manifested in the video. The change was their main agenda from the parent view to leaders to a normal one. The play in the video is to advocate for human righ ts and dignity. The video music describe a sexual orientation generations with multiple sexual partner contributing the spread of HIV/AIDS. The disease affects people across all culture implying that there is intermarriage across the cultural boundaries. The actors in the cosmic play portray a picture in which there is lack justice for the poor. Due to high moral decay, corruption is considered as a vice that affect the society in many aspect. The need for change in all the sectors of economy is eminent right from the leaning, social and political institutions. To condemn the evil practice in this generation video and film are the best method in which to attack those that practice the evil practices indirectly in the

Valuation of TESCO PLC Essay Example | Topics and Well Written Essays - 5000 words

Valuation of TESCO PLC - Essay Example Tesco has also entered the US market in 2007 under the name Fresh and Easy and is planning to invest about $500 million for starting a network of 150 stores in the US West Coast. Its retail operations include groceries and food items which accounts for almost 80% of its sales and also has a very profitable online trading business. The company also sells non food items like clothing, electronics, pharmaceuticals, books, insurance, alternative medicines, certain legal services, petrol etc. In terms of turnover Tesco Plc is the fourth largest retailer in the world, the 1st three positions being held by Wal Mart, Carrefour of France and The Home Depot of the USA respectively and ranks 59 in the Fortune Global 500 according to CNNMoney.com. The group has around 3000 stores and employees around 400,000 people worldwide. It is at present the largest employee in Britain in the private sector. The turnover of the company for the twelve months ending December 2007 was  £46 billion and it has increased profit every year except in 1987. As in the case with most fast growing companies Tesco has had its share of accusations and criticism which includes undercutting the competition, exploiting suppliers and workers and of employing child labor in certain markets. Early Days and later expansion: In 1919 John Edward Cohen started a small grocery shop in East London with a thirty pound stipend he received from the Royal Flying Corps. One of the products he sold was a private brand of tea named Tesco, derived from the name of his supplier Mr. T E Stckwell (the first three letters of his name TES and CO from his surname) and he used this as the name of the his store which he opened in 1929 in North London. The company was incorporated as a private limited company in 1932 named Tesco Stores Ltd. His business flourished and a new headquarters was built on a

Global Trade and Distribution Strategy Coursework

Global Trade and Distribution Strategy - Coursework Example In some cases, imported goods are of low quality hence they have cheap prices which make people shun products that are locally manufactured. 2. The target market for the Achilles kids shoes mainly include the parents who have young kids. The kids themselves are dependent on their parents for all their clothing needs. The company ought to identify factors such as levels of income of the targeted group. In order to cut costs, distribution strategy that would work for this target market is that the company performs the distribution of the products itself. After the products have been manufactured, the company ought to identify the channels through which the products will be distributed. The products should be sold through company operated stores since this helps to attract many customers. More importantly, this helps to reduce costs since other suppliers may charge more money for performing the same task of distributing the finished

What is new media Essay Example | Topics and Well Written Essays - 500 words

What is new media - Essay Example nication content, such that either unique content would be passed on to one individual at a time, or general content would be passed to many audiences at a time, but both would not occur simultaneously (Crosbie, 1998). The old media comprised of one-to-one (interpersonal communication) or one-to-many (mass communication), where the interpersonal communication would allow for passing a unique content to one person only; at a time, while the mass media would allow for the distribution of the same message to a large audience, but without the ability to make the content individualized or made unique for any single individual (Crosbie, 1998). Thus, the New Media can be defined as the mode of communication that allows for unique and general content transmission at a time, meaning that using the new media, an individual can be able to communicate a unique message to a selected individual in form of a one-to-one communication, and at the same time be able to send a general communication content to a wider audience (Crosbie, 1998). Thus, New Media is characterized by the possibility of democratization of the communication content; the possibility to send and receive communication either in the form of unique or general content for an individual. The New Media can also be defined as a creation of the technological advancement, such that it is a communication media that could not have been possible if technology did not exist (Manovich, 2001). It is possible to communicate one-to-one without any technological aid, for example through face-to-face communication of two individuals. Additionally, it is possible to communicate to a wider audience without the use of technology, for example a leader addressing a gathering. However, it is not possible to communicate a unique content to one individual and pass general information to the rest of the gathering, if technology does not exist. In this respect, New Media is the communication media that is technology-dependent, and which

Personal Case Study Paper Example | Topics and Well Written Essays - 1250 words

Personal Paper - Case Study Example Role conflict can come in various forms. Role conflict usually comes in the form of status, role, and expectation. There are a number of academic researchers that have been carried out with regard to role conflict. This paper aims at discussing how academic research relates to role conflict. There is always a variance in opinions when it comes to how role conflicts should be handled. However, what is certain is that the manner in which you manage role conflict determines how it will affect your organization. Regardless of the roles played or the individuals involved in a conflict both sides are always negatively affected by the conflict. Berko, Aitken & Wolvin asserts that when interdependent individuals or groups happen to have views, opinions, values, and goals that are conflicting it will be hard for them to work for a common course (Berko, Aitken & Wolvin, 2010). People who ignore role conflicts have a higher possibility of failing as compared to those who acknowledge their existence and work towards solving them. To make sure that role conflicts are put under control roles of the various individuals and groups that are interdependent should be defined. This will help everyone understand the boundaries of their roles and the importance of their role to the common purpose. When choosing or allocating roles you should make sure that people or groups are given the roles that they are best in. This will be in the bid of making sure that everyone is comfortable with the roles that they are supposed to play (Settles, Sellers & Damas Jr, 2002). This will mean that by the end of the day everyone would have played their roles and since the common course is dependent on the individual roles the common course will be achieved. However, Beaucham and bray asserts that letting people and groups play the roles that they are best in will reduce the possibility of there being complaints from the other individuals or groups involved in the course (Beauchamp &

The Impact of Training and Development on the Employees of the Insurance Sector in Jordan Essay Example for Free

The Impact of Training and Development on the Employees of the Insurance Sector in Jordan Essay The focus of all aspects of Human Resource Development is on developing the most superior workforce so that the organization and individual employees can accomplish their work goals in service to customers , All employees want to be valuable and remain competitive in the labour market at all times. This can only be achieved through employee training and development. Employees will always want to develop career-enhancing skills, which will always lead to employee motivation and retention. There is no doubt that a well-trained and developed staff will be a valuable asset to the company and thereby increasing the chances of his efficiency in discharging his or her duties, so our main focus about the practises of training and development in the insurance sector as it is a very important service sector . And to study the relationship between training and development with job satisfaction and morale among employees , inter personal relationship and customer satisfaction , employee motivation, efficiencies in processes, financial gain , capacity to adopt new technologies and methods , innovation in strategies and products , employee turnover , company image and productivity. METHODOLOGY: We are going to examine two of the most well-known companies in Jordan (Arab insurance company and Jordanian insurance company) through a qualitative research , data will be collected through a couple of interviews with some of the employees of the two companies from many managerial levels and by gathering primary information through literature review from recent journal papers and books. GROUP MEMBERS: * Sara khano * Bashar Kafafi * Lama Daas * Eman Khalil * Shireen Shakaa

The Meaning Of Catholic Church Architecture Theology Religion Essay

The Meaning Of Catholic Church Architecture Theology Religion Essay Theology in Stone: The Meaning of Catholic Church Architecture. If a tour of the Catholic churches were to be formed, you would be in need of a guide. The reason for this is simple. Catholic churches have assigned symbolic meaning to the various parts of the church building. This symbolism is shown not only on the exterior of the building, but also through-out the interior and the Holy items within. There are several misconceptions surrounding Catholic churches and its architecture. One myth about the church states that the Vatican Council requires the rejection of traditional church architecture and the promotion of more modern architecture. This myth is supported by what Roman Catholics have built during the last three decades rather than what the Church has taught. Even by vocational reports, the church architecture of the past decade has been a complete calamity. Nevertheless, actions frequently speak louder than words, and the faithful have been led to accept that the Church necessitates its structures to be functional abstractions. There has also been controversy surrounding the Catholic church praising saints or items and symbols, it is easy to see why someone may say that it is not possible or welcomed to build a beautiful church. This happens to be completely wrong. We live in an age where men have been flown to the moon and insanely ample sums of money are exhausted on sporting arenas. Of course we should also be able to construct these structures of the same quality as the previous Christian basilicas or Gothic cathedrals. In recent layman architecture we are observing a great resurgence of traditional architecture and craftsmanship. Following the book Ugly as Sin, there are three natural laws of Catholic church architecture. The church must have verticality [1]. It is said that a good, successful, and vertical church will stick out above the other smaller buildings in the area. This is so the heavenly Jerusalem (which I interpret as Heaven) is passed through the church. Verticality, itself creates this condition of existence. Its this beingness that makes divine architecture at all possible. Windows, columns, supports, and sacred art should fortify this heavenward ambition. The ceilings pronunciation should create a sense of transcendence toward the Heaven through the mosaics and murals as well as the use of natural light used on the body of the church. (Ugly as Sin, 24) The second of the three natural laws of church architecture is permanence [2]. The building itself symbolizes Christs presence in the world. (Christs presence in the world is the same yesterday and today and forever.) The same thing goes for the church. It must be lasting and surpass space and time. Typically, stone or brick will be used as the material to form the exterior of the church in order to satisfy permanence. This permanence is yet another way of creating transcendence. An authentic Catholic church construction is a work of art that communicates the preceding importance of the Churchs architectural heritage. It refers to the past, serves the present, and informs the future. (Ugly as Sin, 26) The last natural law, Iconography [3]. The Catholic church must have Iconography, this will distinguish the building as a church. A creditable church will also use iconography to capture something bigger. meditation; painting, sculpture, and architecture are meant to work together to produce a unified effect. (St. Ignatius Loyola) This is said to emphasize the importance of beautiful creations in the world. A churchs architectural appearance should reverberate Gods creation. In specifically, man, who was made in the image of God. Art has been, is, and will be forever, the greatest agency for spiritual impression that the Church may claim. writes architect Ralph Adams Cram. He writes in addition; because of art, Christians have defined the creative symbolism that lift us to God. The iconography may also display the life of Jesus through-out the Church in a story of pictures, symbols, items, or furniture. (Ugly as Sin, 27) Our journey will lead us to the front, or facade of the church which may be the most artistic and memorable piece of the church. There could be elaborate stained glass, sculptures or memorials in the facade. The stained glass is most commonly above the large wooden doors that create a gate-way that guards the interior of the church. Often the facade shows a story formed around the detailed artwork. When discussing the shape of the church, other than height, you will find the building to be in the shape of a cross. Also, the church transepts will be pointing to the North and South. A transept is the transverse arm of a cruciform church. The left transept is the North transept and the right transept is the South transept. A dome is usually formed at the center of the transepts. The liturgy is supposed to be conducted facing East under this dome where Gods people have gathered. Upon entering the church, you come to the Narthax, which means entry. The transition from the outside world to the inside. This can also be a covered porch-like structure outside of the building. A certain attitude should be attributed to the scents and sounds when entering the Narthax. As you progress through the church, you will find the Nave, which means ship in Latin. This is where followers sit or stand when receiving the liturgy. Churches in the Gothic era typically had screens covering the sanctuary. This area was treated as the Holy of Holies. The sanctuary is where the Tabernacle is kept and where there should be a burning tabernacle light. When the Tabernacle is presented, followers genuflect. When the Sacrament is exposed, Catholics kneel on both knees. The alter is the next significant item found in the Church. The Altar should be set and made of stone and contain a relic of a Saint (usually a hair or other small body part). This is also where the Tabernacle is usually kept. (Jeremiah) The Church performs many functions. Of the most important, there is, worship, hymns or songs, and discipline. Worship facilitates our relationship with God and makes it possible for us to communicate with him in both private and public. Worship more commonly is a public function, done in the mass and amongst other believers. Hymns are another pertinent aspect or function of the church. These allow us to express feelings and emotions we have for God and and the relationship weve formed with him. We also see discipline in the church, this is spiritual discipline. This faithfulness regards our hearts, psyche, and spirit. Prayer should be something we Christians enjoy doing and desire being a part of. It may sound like discipline is referring to punishment, when the real meaning of discipline is something that disciples, or enables (learning). Discipleship refers to the continuous teaching and mentorship. Passing the word through the generations. It has been said, no man is good left alo ne. Nor is it good for a Christian to be left alone. We must encourage ministry by giving permission, training, tools, and removing any impedance. (Six Functions of the Church) Two are better than one, because they have a good return for their work: If one falls down, his friend can help him up. But pity the man who falls and has no one to help him up! Though one may be overpowered, two can defend themselves. A cord of three strands is not quickly broken (Ecclesiastes 4:9-12). Fellowship can serve as a mutual relationship among Christians. Fellowship means sharing life experiences, emotions and burdens. This encourages Christians to help not only one another but also those who do not believe in Christ. All of these functions are served by the Catholic Church and serve a distinct, pious, purpose for members of the church. (Six Functions of the Church) The architecture that forms the church is invariably important to the teachings of the bible and Jesus life. The shapes, scents, and designs assist the learning and provide certain sensations that parallel the traditional mass and liturgy. Architecture plays an important part as symbolism for the church. Much of the artistic features about the church represent something greater or tell a story. The church must also seek to perform a few major functions; worship, hymns, and spiritual disciplines. All of these functions are to bring us closer to God and his heavenly Jerusalem and every aspect of the church is to transcend the spirit through-out us, Gods people. Cites: Ugly As Sin ECN Article Jeremiah, David. Signs of Life. Thomas Nelson, Publishers, 10/02/2007. Print. Six Functions of the Church.  GCI. N.p.. Web. 11 Mar 2013. .

and then there were none :: essays research papers

Trust, Deceit, & Immorality in And Then There Were None, a mystery novel by Agatha Christie, discusses matters of trust, deceit, and immorality. These two words are present within each chapter, and they come to us in ways that do not meet the eye right away. They require a certain level of thought in order to be understood clearly. In which Agatha Christie hopes to bring out. Trust is a key element of life. We need to choose who we can confide and believe in. If the ten people on the island want to stay alive, they need to be aware of those who are truly loyal, but they need to choose wisely, for one out of the ten is a murderer. Everyone in the house has there suspicions. No matter what the circumstances are, they remain immutable about not trusting each other. Having no trust makes all of them a nervous wreck, making each of them more susceptible of being the next victim of murder. Having no trust only digs us a deeper hole to the inevitable, and when we trust the wrong person, the inevitable happens sooner than expected. Deceit, unfortunately, is also a part of life. Deceit inside And Then There Were None, however, is a part of death. Lombard and Vera face the facts when they appear to be the last ones alive on the island. Instead of being the nice man he seemed to be, he turned out to be a miscreant. Lombard fools a lot of people with his act of being paranoid of having the killer looking over his shoulder. It is his self that he needs to guard, and he is not doing a good job of that, because Vera kills him instead. Death comes about in many ways. Murder is one of them. This immorality is the basis of the whole entire book. One by one, each one of the ten people die by someone else’s immoral actions. Even at the end of the book when Vera shoots Lombard, she had committed a brutal crime. Yes, she was defending herself, but she still chooses to use her hands to take someone else’s life. Immorality plagues society today deeply. We have twisted morals so much that the may think the most wr ong action is OK. And Then There Were None is a book that applies lives ways in forms that come to us unconsciously.

Color as a Symbol and Symbolism in Toni Morrisons Beloved Essay

Use of Color as a Symbol in Beloved  Ã‚        Ã‚  Ã‚   In Beloved, Toni Morrison portrays the barbarity and cruelty of slavery. She emphasizes the African American’s desire for a new life as they try to escape their past while claiming their freedom and creating a sense of community.   In Beloved, "Much of the characters’ pain occurs as they reconstruct themselves, their families, and their communities after the devastation of slavery" (Kubitschek 115). Throughout the novel, Morrison uses color to symbolically represent a life complete with happiness, freedom, and safety, as well as involvement in community and family. In many scenes, Morrison uses color to convey a character's desire for such a life; while, in other instances, Morrison utilizes color to illustrate the satisfaction and fulfillment, which the characters experience once they achieve this life.   Ã‚  Ã‚  Ã‚   Morrison uses color to symbolize the life Paul D desires as he is heading North. When Paul D asks the Cherokee man â€Å"how he might get North.   Free North.   Magical North,†Ã‚   (Morrison 112) he conveys his desire for a free, safe, happy and even somewhat magical life.   Equating color with this life, the Cherokee man replies, â€Å"Follow the tree flowers.†Ã‚   When one thinks about or describes flowers, their colors are always important.   In his journey North, Paul D would â€Å"scan the horizon for a flash of pink or white...[or] blossoming plums† (Morrison 113).   By having Paul D search for colorful flowers, Morrison illustrates Paul D’s desire for a life full of safety, enjoyment, and freedom.   Ã‚  Ã‚  Ã‚   Just as Paul D desires a better life after slavery, so does Baby Suggs.   As a slave, Suggs was suppressed and did not experience the type of life she desired.   Morrison indirectly demonstrates... ...e beauty of this land that was not† theirs (Morrison 268).   â€Å"They cling to its banks to lap water and tried not to love it;† for, their life was not their own (Morrison 268).   Thus, when the slaves are able to experience color, like Denver when she is a part of the community, the symbolism of color is very powerful.   It symbolizes a character’s ability to own a feeling or emotion.   For example, when Sugars dies, she concentrates on color because that is one thing in her life which she owns.   The effects of slavery have destroyed her family, community and even freedom.   Therefore, she focuses on color because it is her own experience and the happiness she feels from pondering color is her own.    Works Cited Kubitschek, M.D. Toni Morrison: A Critical Companion. London: Greenwood Press,  1998. Morrison, Toni.   Beloved. New York: Plume Printing, 1987.   

The Reality Of Bertrandes Innocence Essay -- essays research papers

It seems as though in today’s society, suspicion lies in every corner. No one trusts anyone anymore, everyone lies, everyone steals, everyone pretends to be someone they are not. However true or false these statements might be, there is a need in today’s society to be able to explain everything, coming up with every possible lie or predicament within every story. Natalie Davis is from today’s society, and once again, she has found the need to investigate Bertrande Guerre’s role within The Return of Martin Guerre. The only pieces of evidence that are reliable come from Jean de Coras, the main judge in the trial. However, Davis seems to have ignored his findings, and founded her own. For most of her points, there is no written evidence to back her up. She simply read and interpreted the story, as many historians must do to come up with plausible reasons for things; however, she interpreted the evidence incorrectly. This impostor known as Arnaud du Tilh, who played a husband, father, friend, nephew and brother for three years, deceived an entire town. However, Davis has chosen Bertrande Guerre as a co-conspirator, with little grounds to base her conclusion upon. Therefore, I still have found that Bertrande Guerre truly believed that Arnaud du Tilh was her husband, making her an unknowing player in the entire charade.   Ã‚  Ã‚  Ã‚  Ã‚  Natalie Davis made the point that Bertrande must have known that the new Martin was an impostor due to their sexual relationship and the differences therein (110). However, this point is hard to believe due to the fact that Bertrande and Martin were married for nine years without having intercourse, and when they finally did, it was in order to conceive their future son, Sanxi (Finlay, 558). Only a few months after Sanxi was born, Martin disappeared for over eight years, which is a long time for a woman to remember the specific details of a sexual relationship that couldn’t have lasted for more than a few months (Finlay, 558). Even if Bertrande had noticed a difference in the sexual relationship, she would have doubted her recollections, not having any kind of proof or true memories of those sexual experiences (Finlay, 558). This â€Å"new Martin† could have also become more sexually experienced while soldiering, explaining his newfound confidence (Finlay, 558).   Ã‚  Ã‚  Ã‚  Ã‚  The two men seemed to have com... ...wn, Natalie Davis made up a tale of what happened, ignoring the actual story that had been recorded by one of the lead characters who was there at the time, Jean de Coras. While her points had good merit, there was little evidence besides her opinion and suspicion that backed her up. Bertrande de Rols was deceived by this man, just as everyone else was. Whether she enjoyed her time spent with Arnaud is not important, it is whether or not she was fooled. While there were many who were suspicious, and many who were uncertain of Bertrande’s innocence, there was not a majority that truly believed she was a co-conspirator. She was not proven guilty by Jean de Coras nor was no proven guilty by the townspeople. The townspeople had fallen for Arnaud’s acting, and it is certain that Bertrande had fallen for it as well. And as each of these people would say, Arnaud was a wonderful actor, who was educated in Martin’s life and the people within it. Stories such as these are reminders as to why history is not always objective, and that historians have the right to interpret it in any way that they choose. However, a good historian will always have his critic.   Ã‚  Ã‚  Ã‚  Ã‚  

Crime and Legal System Essay

In the broad field of criminal justice, one particular issue critically relevant in the concern of crime prevention and social control is juvenile delinquency due mainly to the fact that its target population are the minors in the society. The concept of juvenile delinquency generally encompassed numerous concerns namely the crimes involving minor offenders, the court system to address these cases, the punishment approach for the young individual, and others relevant in achieving an effective approach for achieving the ideal justice for these young offenders. In this pursuit, incorporating sociological concepts can indeed promote development in the effectiveness of the criminal justice system for cases of juvenile delinquency. In analyzing the criminal justice system for minor offenders, it is critically important to consider several factors directly related to the effective achievement of its function. Among these factors are the effect of the punishment to the minor offender, beneficial alternatives for the criminal punishment, motivational strategies of behavioral development, influence of personality background, and others. Incorporating the sociological perspective in this concern, the said field explains that the family structure, environment, and culture are influential factors to the individual’s personality and behavioral development as such, should be considered in determining the appropriate action for cases of juvenile delinquency. Indeed, incorporating this approach will reveal a more appropriate, effectively altercating, and motivational action towards addressing the personal problems of the young offenders resulting to their juvenile delinquency. Indeed, sociological, the youth period in the timeline of each individual is a critical condition wherein the person encounter personality confusion and identity struggle. During this period, the erratic behavioral changes in the person can result to aggressive actions and decisions and if influenced by negative factors can result to juvenile delinquency. As such, approaching the view through a sociological perspective, it is more advantageous to tackle the problem by helping the offender cope up with his or her personal changes and struggle and guide the person to the proper way. Indeed, developing the punishment system in this approach can result to an effective juvenile justice system that promote healthy development through guiding the misdemeanor of the minor offenders towards fruitful growth and development for their benefit. In this approach, the issue of juvenile delinquency will be addressed by minimizing the problem and taking this approach as a mean of helping the youth through the growth.

Necessary Convergence Communication Essay

A Theory of Dyadic Social Interaction and Meanings Michelle Miller-Day In this paper, the author proposed and describes a theory of the social construction of meaning in dyadic communicative interaction. The author argues that necessary convergence communication is a theoretical framework useful for explaining how power may influence the process of meaning construction in interpersonal communication. This essay describes the features of this theoretical framework and provides theoretical suppositions for future empirical testing. Child:Mom, look at the blue package! Mother: It’s not blue, it’s teal. Child:It looks like blue to me. Mother: It’s not though. It’s got green in it too, so it’s teal. Later that day Friend: Oh, that’s a pretty package. The blue matches your shirt. Child:It’s not blue, it’s teal. To many of us this scene is not unusual. Children often learn from elders what any given symbol â€Å"means† and once children learn these meanings they incorporate them into their cognitive schemata. According to Piaget’s (1972, 1954) theory of cognitive development, from approximately ages 4-7 children are in an intuitive phase where they can grasp logical concepts, but reality is not yet firm and is often dictated by authority figures. The role of authority figures to shape constructions of reality certainly does not end in childhood. Social constructionists such as Berger and Luckmann (1966) argue that individuals â€Å"together produce a human environment, with the totality of its socio-cultural and psychological formations and understandings; social meanings are a human product â€Å"(p. 52). It is not unusual, say, for an abusive romantic partner to convince his or her partner that the abuse is deserved or symbolic of care or even love. The dyadic construction of acts of abuse as signifying love or care may not e clearly understood by others outside the relational dyad, yet perceptions of abusive behavior as acts of love are common in abusive interpersonal relationships, along with sacrificing one’s own interpretation of events so as not to lose the affection of the partner (Woods, 1999). In fact, in a recent episode of the popular television show Law and Order: Special Victims Unit (Denoon & Platt, 2004) a teenager was placed in foster care due to a mother’s complete and utter dominance over t he child, with the episode focusing on the control the mother had over how her offspring interpreted the world around him. The psychologist in the episode did not have a name for this process of maternal domination, but compared the teenager to a â€Å"puppet,† merely appropriating his mother’s interpretations of the world out of fear; the fear of losing her love, protection and their relational structure. Although this essay does not focus on children or abusive relationships specifically, it outlines a theory addressing the social construction of meanings in dyadic communicative interaction wherein there is disequilibrium between members in that process. Berger (2005), in his review of the interpersonal communication up until the 21st century, pointed out that very few interpersonal communication scholars have developed theories addressing this central tenet of communication –meaning. His review argued that for the field to move forward interpersonal communication researchers should look more at interaction routines and the process of meaning-making between interactants. Around the same time as this review was being written, Koerner and Fitzpatrick (2002) published an article in Communication Theory arguing for a similar need for research examining intersubjectivity, meaning, and interactivity in the area of family communication. They argued the following: â€Å"†¦ a complete explication of family communication needs to consider both intersubjectivity and interactivity (Fitzpatrick & Ritchie, 1993). Intersubjectivity refers to the sharing of cognitions among participants in a communication event, whereas interactivity refers to the degree to which the symbol creation and interpretation are linked. ,Interactivity refers to the way that a family maintains its own structure through patterns of family members’ responses to each other’s communicative acts† (p. 73, Koerner & Fitzpatrick, 2002). Correspondingly, Miller-Day (2004) also presented a Necessary Convergence Communication (NCC) theory which focused on both intersubjectivi ty and interactivity in family member interactions, while addressing issues of power and dominance involved in the process of meaning-making between communicators. At this junction, in response to these calls for theoretical development in the area of meaning construction and dyadic social interaction in the fields of interpersonal and family communication, and building on the ideas introduced by Koerner and Fitzpatrick (2002), this essay will briefly review the original ideas of Miller-Day’s (2004) Necessary Convergence Communication (NCC) theory, elaborate on them, and then discuss how this framework might be a workable mid-range theory to assist communication scholars understand how the construct of power or dominance may influence the meaning construction process in interpersonal communication. A theory is a lens through which to examine human interaction and theories have four functions–description, explanation, prediction, and change (Griffin, 2000; Littlejohn & Foss, 2005). The foundation of a theory is description and as Wood (2004) points out, â€Å"before we can figure out how something works, we must describe it† (p. 32). Therefore, the first task of building new theory is to describe its features. This essay provides a description of necessary convergence communication and identifies specific features that may be empirically tested. An Introduction to Necessary Convergence Communication Miller-Day (2004) argued that necessary convergence is a form of intersubjectivity that occurs during a pattern of interactivity when one communicator is dominant and the other submissive. When convergence of meaning occurs, meaning coordination tends to be coercive rather than cooperative with the dominant partner’s interpretive frame privileged over the submissive partner’s, leading to unequal contributions to the process of meaning coordination. Author Ayn Rand (1993) referred to this type of process in her novel The Fountainhead. Rand argued that some individuals tend to be â€Å"second-handers†Ã¢â‚¬â€people who don’t judge for themselves, who just repeat what others close to them say, embrace it, and make it their own. Miller-Day’s (2004) argument suggests that when the relational schema for the submissive partner is based on conditional regard—that is, she or he believes that acceptance in the relationship (e. g. , receipt of emotional resources) is contingent on meaning convergence; the submissive partner will converge with the dominant partner’s meanings for relational maintenance purposes. As discovered in Miller-Day’s family communication research (2004) and Miller (1995) and illustrated in the Law and Order episode mentioned earlier in this essay, not to converge with a dominant partner’s interpretation of symbols or events in any transaction would risk already precarious acceptance and approval in the relationship. An interpretive frame is defined here as cognitive structure that contains mental representations of meanings; the process of constructing meaning activates interpretive frames. Necessary infers that convergence is perceived as essential to achieving a certain result, and convergence indicates a tendency toward one point (Miller-Day, 2004). Thus, to obtain relational approval and avoid rejection, the submissive partner will accommodate the dominant partner by assimilating his or her interpretive frame. Within this model, convergence is relationally adaptive. This introduction to NCC as a theoretical framework offers an overview. But, to fully understand how this theory may be applied more generally to interpersonal relationships, I will elaborate on this theoretical framework, present the assumptions linked to it, describe its characteristics, and provide some theoretical statements for empirical testing. A-Priori Theoretical Assumptions Communication Is an Emergent, Creative Activity through Which Meanings are Coordinated Via Interpretive Schemata People approach the world through processes of interpretation. As human social animals we are in a constant state of interpreting and managing meanings, and interpreting meanings is an interdependent process. The assumption is that meanings are not inherent in objects, but instead arises out of social interaction. During social interaction, meanings are coordinated through interpretive schemata—mental structures consisting of organized knowledge about relationships. Interpretive schemata represent accumulated knowledge—the sum of past experiences—which help an individual interpret, understand, and predict the outcomes of interactions with others (Burleson, Metts, ; Kirch, 2000; Cragan ; Shields, 1998; Koerner ; Fitzpatrick, 2002). Moreover, interpretive schemata include expectations about what should happen in a given situation and serve to guide behavior. Interpretive schemata specific to relationships—relationship schemata—influence the â€Å"encoding and decoding of information, the inferences and evaluations people make †¦ and ultimately their interpersonal behavior† in relationships (Koerner ; Fitzpatrick, 2002, p. 80). This assumption presumes that the process of â€Å"making meaning† activates interpretive frames. Communicators then coordinate their meaning systems as filtered through these frames and then negotiate agreement. Understanding between the members builds intersubjectivity and hopefully leads to consensus (Crotty, 1998; Solomon, Dillard, ; Anderson, 2002). Implicit in this assumption are claims of coordination and negotiation. Coordination implies a state of equal rank, equal power, and harmonious order, whereas negotiation suggests that communicators confer with one another in order to reach an agreement. Coordination involves collaboration of all communicating partners. Communication Enacts Relationships The state of being in a â€Å"relationship† is inherently a communication process and must be understood as a series of transactions in which messages are exchanged. Relationships are formed across repeated transactions, with each new transact adding new information to the one that came before, building a cumulative database of information about the relationship (Burleson et al. 2000; Duck, 1992; Guerrero, Anderson, ; Afifi, 2001). Transactions are units of interaction affecting both interactants and carrying commentary on the interactant’s relationship. As Watzlawick, Beavin, and Jackson (1967) pointed out, each message (both verbal and nonverbal) carries information at two levels—the content level and the relationship level. The relationship level enacts the current state of the relationship and provides information about how the communicators see each other, t hemselves, and their relationship. Communicative Transactions in Close Personal Relationships Have Implications for Personal and Relational Identities Relational members encode and decode information about themselves as well as for their partner, extrapolating this information to the relational unit (Aron ; Aron, 1986). Within this framework, the self is conceptualized as inseparable from dynamic interaction, with each transaction contributing to both self- and relational knowledge. Early work by Mead (1934) identified the centrality of essage exchange in personal identity management. More recent work in relational communication points out that both personal and relational identities are cocreated communicatively within the context of relationship (Wilmot, 1995). Personal identity development is really the unfolding of the self while retaining relational ties; identities are constituted and managed through relationships, not to their exclusion (Adams ; Marshall, 1996). Relational Culture Shapes Interpretive/Relational Schemata Relational cultures consist of shared meaning systems, routinized patterns of interaction, and norms that structure members’ roles and behaviors (Wood, 2000). These cultural norms shape relational schemata (Koerner ;Fitzpatrick, 2002), and these schemata are socialized across the developmental trajectory of the relationship. Socialization involves the â€Å"social and communicative processes through which cultural knowledge, resources and practices are made available and internalized† by cultural members (Burleson et al. , 2000, p. 35). As Entman (1993) demonstrated, culture is the stock of commonly evoked interpretive schemata and culture might be defined as the â€Å"empirically demonstrable set of common interpretive frames exhibited in the discourse and thinking of most people in a relationship† (p. 53). Relational schemata are the mental structures that are socialized within a relational culture, organize knowledge about relationships, and are used to process information relevant to these relationships. Therefore, relational cultures will share common schemata and should be reflected in the communication practices of relational members. Interpersonal Scripts Emerge From Relational Schemata Scripts are one form of communication practice enacted within relationships that emerge from relational schemata (Koerner ; Fitzpatrick, 2002). Relational scripts direct interaction, exemplify relational work, and dictate normative ways of issuing directives and responses. Scripted interactions are often routine, habituated, and overlearned through repetitive practice in the family culture (Sillars, 1995); however, these scripts are useful in directing the â€Å"typical† ways in which an interaction should be handled given the particular relational schema. When relational members become practiced in these roles and memorize their lines, these enactments become scripted. That is, partners may not think about their day-to-day ways of interacting with each other on a conscious level, but they may still tend to communicate in patterned ways with well-defined scripts that enact â€Å"appropriate† relational behavior. These a-priori assumptions are implicit in the theoretical framework of NCC. In summary, they presuppose that relational culture shapes partner’s knowledge of relationships; each partner’s accumulated knowledge of relationships helps her or him to coordinate meanings; patterned or scripted communication behavior emerges from relationship schemata; and this communication behavior is consequential for interpersonal relationships. Characteristics of Necessary Convergence Communication Necessary convergence communication can be captured by describing its three separate characteristics, equilibrium, weighted proportion of meaningfulness, and motivation, and two process dimensions, degree and chronicity (Miller-Day, 2004). These characteristics are illustrated in Fig. 1 and can be assessed in terms of their valence and intensity in any given interpersonal relationship. [Insert Figure 1 about here] Equilibrium When necessary convergence occurs, there tends to be disequilibrium in the relational coordination of meanings. Equilibrium refers to an equality of distribution; however when disequilibrium occurs, there is unequal power to determine meanings in interpersonal interaction. Power is a person’s ability to control valuable resources and is often tied to status. Any type of power such as expert power, legitimate power, or coercive power is relevant to equilibrium as long as the person is in control of resources considered valuable. Control of resources provide the potential for the exercise of power in most relationships, with resources being all knowledge, skills, emotions, words, actions, and materials that are at the disposal of the person. Given the distribution of resources within any specific interpersonal relationship, power might be evaluated by its outcome, which is dominance. Dominance refers to the degree to which a person can influence and impose their will on the other; its counterterm, submission, refers to the degree to which a person gives up influence or yields to the wishes of the other. I think it is important to keep in mind that dominance itself is determined by the submissive response of others. Moreover, as Burgoon, Johnson, and Koch (1998) pointed out, â€Å"While power enables the display of dominance, and dominant behavior may solidify power—though correlated—dominance and power are not interchangeable concepts† (p. 10). According to Miller-Day (2004), when NCC occurs the relational member who has higher status or more power in the relationship (e. g. , parent, teacher, boss, or romantic partner) would be dominant in imposing, rather than cooperatively negotiating, meaning in the relationship. Moreover, as one person’s power to determine meanings increases, the other person’s decreases, this then leads to an unstable situation in which the importance of one partner’s interpretive frame outweighs the partner’s. Weighted Proportion of Meaningfulness The second characteristic of necessary convergence occurs when one partner submits to the unequal distribution in the power to construct meanings in interaction. Dominance requires submission. Consequently, when a lower-status partner submits, she or he affords the dominant partner’s meanings more weight—more significance—in the transaction. Developmentally, as most individuals begin to acquire personal authority they naturally become differentiated from parents and others in their life, even as they remain emotionally connected (Nadien ; Denmark, 1999). However, as adults form unique relational cultures, they will develop new connections with others. Some times these relationships are purely social and require accommodation of meanings for social management purposes; for example, in the classroom where a professor does not encourage critical thinking but mandates rote memorization and resists any challenge of information. In this case, students are required to accommodate the professor’s meanings into his or her own understanding (and repeat that on the exam! ). Anyone who has ever been in a classroom with one of these instructors may empathize with students placed in a setting where there is a low tolerance for differentiation in thinking among members. But the case of relational partners where one partner is dominant in most realms of the relationships and the other submissive, there is both a social and emotional connection between partners. In this case, the dominant partner will typically closely monitor any behaviors that signify the submissive partner’s movement toward differentiation (uniqueness outside the relationship), regardless if emotional ties remain undisturbed. If the less powerful partner resists the imposition of meaning and challenges her partner’s construction of meaning in the dyadic interaction, then necessary convergence communication has not occurred. It is the absence of resistance –the convergence–that is a key feature of this kind of communication. According to NCC, the less powerful partner will be motivated to converge because he or she feels it is necessary. Motivation Motivation is a reason for action, an incentive. This theory argues that when there is a compelling reason for convergence, such as is to avoid undermining the relationship or to secure relational acceptance, there is increased motivation to converge with the higher-status partner. When acceptance in the relationship is perceived to be conditional on that convergence, then convergence is perceived as relationally adaptive and the lower-status partner is more likely to perceive convergence as necessary. Necessary convergence, then, might be viewed as a form of secondary control. According to Rosenberg (1990), â€Å"Secondary control is an attempt to accommodate to objective conditions in order to affect a more satisfying fit with those conditions† (p. 147). Although convergence tends not to be explicitly demanded, lower-status partners will perceive it as a condition for relational acceptance. Manipulation of resources in a relationship, such as support, regard, or inclusion, emerged as a significant contributor to asserting dominance in the family relationships observed by Miller-Day (2004). As a form of psychological control, higher-status family members offered and withheld these resources contingent on the convergence of the lower-status member. The manipulation of emotional resources, therefore, was used to assert psychological dominance with the provision or withdrawal of resources providing a compelling motivation for lower-status partner’s convergence. According to NCC, once convergence is perceived to be necessary, and one accommodates the dominant partner’s interpretive frame at the expense of one’s own, two additional characteristics become important when assessing necessary convergence: degree and chronicity. Process Dimensions Degree. The relative intensity or amount of convergence in any given dyadic interaction is important to the process of NCC. The following illustration captures different degrees of convergence. Example: An adult woman and a friend are talking. The friend comments that she likes the woman’s new hairstyle, pulled up on her head with a hair clip. The woman comments that she likes the style too. Soon the adult woman’s mother walks into the room, looks at her adult daughter, and with a tone of disapproval says, â€Å"What have you done to your hair? It looks awful† Under conditions of high convergence, the lower-status woman would change her hairstyle extensively as a result of her mother’s comment, converging with her mother’s interpretation that the style was indeed horrible and altering her original interpretation to â€Å"fit† more closely with her mother’s. If asked by another, she would explain that the hairstyle looked awful so she altered it. Under conditions of moderately high convergence, the lower-status woman would significantly change her hairstyle as a result of her mother’s comment, but just to please her mother or to reduce conflict. The lower-status woman would not alter her own interpretation to fit with her mother’s interpretation; she would merely accommodate the alternative interpretation. Under conditions of moderately low convergence, the lower-status woman might make minor alterations in the hairstyle to integrate both perceptions of what was attractive into one style. Finally, under conditions of low convergence, the lower-status woman might listen to her mother’s comment but keep the style anyway because she likes it. As Miller-Day (2004) comments, there are times when we all perceive that it is just easier, necessary, or politically astute to adjust our interpretations to others’ view of the world. However, when there is extensive accommodation and convergence, obliterating personal interpretative frames constitutive of self, this might negatively influence personal identity. Chronicity. Convergence may be chronic or the pattern of convergence may occur across time and contexts. When lower-status individuals experience repeated failures in negotiating meanings in transactions with a partner across time (e. . , across the life course) and contexts (e. g. , attitudes, values, behaviors), this may instill a generalized expectancy of learned helplessness and â€Å"giving in. † Miller-Day’s (2004) data revealed that women who chronically engaged in necessary convergence had an undefined sense of self and lower self-esteem than women who did not engage in convergence. When boundari es between individuals blur in personal relationships, identities may become undefined and convergence communication becomes the modus operandi. Piaget’s (1972) theory of cognitive development points out that in normal development, both assimilation and accommodation processes are used simultaneously and alternately throughout life. Assimilation being the process of using or transforming the environment so that it can be placed in preexisting cognitive structures and accommodation being the process of changing cognitive structures in order to accept something from the environment. Necessary convergence communication offers an explanation for those interactions where accommodation becomes the primary means of making sense of the world. Theoretical Suppositions of Necessary Convergence Whereas theoretical assumptions are claims already supported in the research literature, suppositions are considered true or existing but not yet proved. Miller-Day (2004) provided the groundwork for this theory development and I seek to build on that by offering the following suppositions about NCC. I believe these suppositions may provide the necessary building blocks for theory development and offer future directions for empirical testing. Supposition #1 Interactants with more power (e. g. expert, legitimate, reward) in a dyadic social interaction will exert more influence in the construction of meaning than interactants with less power. Coordination of meaning involves power and control and according to this theory meanings can be hijacked. When both partners share moderate levels of power in the relationship, it would be predicted that they would enjoy the equilibrium and co-construction of meaning–shared cognitions with a relatively high degree of match between symbol creation and interpretation. But most theories assume co-construction and equilibrium in sharing cognitions. According to NCC, we need to factor in power status of the interactants in the dyadic construction of meaning. Although studies exist that explore social stratification and power in terms of race, gender, and larger cultural hierarchies (see, e. g. , Altheide, 1995; Lyman, 1994), rarely do scholars explore interpersonal dominance and perceptions of status in their attempts to understand meaning construction. Supposition #2 Under conditions where there is disequilibrium—unequal power—in determining meanings in dyadic social interaction, both partners will afford the dominant partner’s meanings more significance. If one participant in the communication event is dominant in the dyad then it is predicted that connections between symbol and interpretations can be coerced, and the interpretations of the dominant partner are privileged in that communication event. Supposition #3 Converging with a higher-status partner’s assigned meanings will function to maintain the relational identity. The act of convergence is relationally adaptive. The act of convergence in any given interaction will serve to protect the entangled identity of the participants and function to maintain the relational status quo. Partners in dominant-submissive relationships will maintains their relational culture through this patterns of responding to each other’s communicative acts–by one requiring convergence and the other converging. Supposition #4 Among submissive partners, necessary convergence communication will be positively related to an undifferentiated self. Relationships demonstrate varying degrees of tolerance for intimacy and autonomy through interactions. In differentiated relationships partners are provided with autonomy, while maintaining respect and intimacy. In undifferentiated relationships boundaries are regulated, with high demands for connectedness, and ultimately impeding individual identity (Skowron ; Schmitt, 2003; Skowron, 2005). Supposition #5 The manipulation of emotional resources by the dominant partner in relationship with an undifferentiated partner will positively predict necessary convergence communication. It is posited that a communication partner who encourages emotional and psychological dependence through the manipulation of emotional resources (e. g. , love, acceptance) will also coerce a high degree of convergence in the communicative interaction. Respectively, a communication partner who is undifferentiated and submits to the dominant partner will perceive that convergence–or a shared interpretation–is necessary to maintain the relationship. Supposition #6 The more chronic and the greater the degree of convergence, the more likely the submissive partner will have a generalized expectancy of learned helplessness predicting increased risk for depression. The theory of learned helplessness (Seligman, 1975) offers a model to explain human depression in which apathy and submitting to more dominant others prevails, causing the person to fully rely on others. This can result when life experiences cause the individual to understand that their own cognitions are irrelevant. Summary This essay introduced necessary convergence communication as a theoretical framework to help explain how meanings can be hijacked by others in interpersonal relationships. Under certain conditions it is predicted that dominant members in interpersonal relationships may be able to control the coordination of meaning in the relationship, subverting the interpretations of the submissive communication partner. Outlining characteristics of NCC (equilibrium, weighted proportion of meaningfulness, and motivation), two process dimensions (degree and chronicity), and posing 6 testable suppositions about NCC, this essay argues that this mid-range theory may be useful in understanding intersubjectivity and interactivity in dyadic social interaction where one partner is dominant and the other submissive. Whether that partnership is interpersonal or relational, there are implications for this kind of communication in understanding interpersonal influence and possibly even mental health outcomes such as depression. Future Directions There are criteria by which theories are judged to be effective. According to Shaw and Costanzo (1970) and Wright (1998), the following criteria may be used for evaluating theories and future research should examine this theoretical framework to assess if it meets these criteria. First, there is explanatory power—do the suppositions of the NCC theoretical framework enable scholars to explain as much of the communication phenomenon as possible? Next, is the theoretical model parsimonious—does it contain as few suppositions as possible, is it as simple as it can be? Is NCC internally consistent, that is, do the suppositions contradict each other? Does NCC have heuristic potential; does it suggest hypotheses to be tested through additional research? Finally, does NCC promote new understanding and have societal value? This essay outlines the features of NCC and proposes suppositions for empirical testing. Future research should test these suppositions with the potential to falsify and/or delimit this theoretical framework.

Heat Exchanger

Heat exchanger An interchangeable plate heat exchanger Tubular heat exchanger. A heat exchanger is a piece of equipment built for efficient heat transfer from one medium to another. The media may be separated by a solid wall, so that they never mix, or they may be in direct contact. [1] They are widely used in space heating, refrigeration, air conditioning, power plants, chemical plants, petrochemical plants, petroleum refineries, natural gas processing, and sewage treatment.The classic example of a heat exchanger is found in an internal combustion engine in which a circulating fluid known as engine coolant flows through radiator coils and air flows past the coils, which cools the coolant and heats the incoming air. Contents| Flow arrangement Countercurrent (A) and parallel (B) flows * Fig. 1: Shell and tube heat exchanger, single pass (1–1 parallel flow) * Fig. 2: Shell and tube heat exchanger, 2-pass tube side (1–2 crossflow) * Fig. : Shell and tube heat exchanger, 2- pass shell side, 2-pass tube side (2-2 countercurrent) There are three primary classifications of heat exchangers according to their flow arrangement. In parallel-flow heat exchangers, the two fluids enter the exchanger at the same end, and travel in parallel to one another to the other side. In counter-flow heat exchangers the fluids enter the exchanger from opposite ends. The counter current design is the most efficient, in that it can transfer the most heat from the heat (transfer) medium due to the fact that the average temperature difference along any unit length is greater.See countercurrent exchange. In a cross-flow heat exchanger, the fluids travel roughly perpendicular to one another through the exchanger. For efficiency, heat exchangers are designed to maximize the surface area of the wall between the two fluids, while minimizing resistance to fluid flow through the exchanger. The exchanger's performance can also be affected by the addition of fins or corrugations in one o r both directions, which increase surface area and may channel fluid flow or induce turbulence. The driving temperature across the heat transfer surface varies with position, but an appropriate mean temperature can be defined.In most simple systems this is the â€Å"log mean temperature difference† (LMTD). Sometimes direct knowledge of the LMTD is not available and the NTU method is used. Types of heat exchangers Shell and tube heat exchanger A Shell and Tube heat exchanger Main article: Shell and tube heat exchanger Shell and tube heat exchangers consist of a series of tubes. One set of these tubes contains the fluid that must be either heated or cooled. The second fluid runs over the tubes that are being heated or cooled so that it can either provide the heat or absorb the heat required.A set of tubes is called the tube bundle and can be made up of several types of tubes: plain, longitudinally finned, etc. Shell and tube heat exchangers are typically used for high-pressure applications (with pressures greater than 30 bar and temperatures greater than 260  Ã‚ °C). [2] This is because the shell and tube heat exchangers are robust due to their shape. Several thermal design features must be considered when designing the tubes in the shell and tube heat exchangers: * Tube diameter: Using a small tube diameter makes the heat exchanger both economical and compact.However, it is more likely for the heat exchanger to foul up faster and the small size makes mechanical cleaning of the fouling difficult. To prevail over the fouling and cleaning problems, larger tube diameters can be used. Thus to determine the tube diameter, the available space, cost and the fouling nature of the fluids must be considered. * Tube thickness: The thickness of the wall of the tubes is usually determined to ensure: * There is enough room for corrosion * That flow-induced vibration has resistance * Axial strength * Availability of spare parts Hoop strength (to withstand internal tub e pressure) * Buckling strength (to withstand overpressure in the shell) * Tube length: heat exchangers are usually cheaper when they have a smaller shell diameter and a long tube length. Thus, typically there is an aim to make the heat exchanger as long as physically possible whilst not exceeding production capabilities. However, there are many limitations for this, including space available at the installation site and the need to ensure tubes are available in lengths that are twice the required length (so they can be withdrawn and replaced).Also, long, thin tubes are difficult to take out and replace. * Tube pitch: when designing the tubes, it is practical to ensure that the tube pitch (i. e. , the centre-centre distance of adjoining tubes) is not less than 1. 25 times the tubes' outside diameter. A larger tube pitch leads to a larger overall shell diameter, which leads to a more expensive heat exchanger. * Tube corrugation: this type of tubes, mainly used for the inner tubes, in creases the turbulence of the fluids and the effect is very important in the heat transfer giving a better performance. Tube Layout: refers to how tubes are positioned within the shell. There are four main types of tube layout, which are, triangular (30 °), rotated triangular (60 °), square (90 °) and rotated square (45 °). The triangular patterns are employed to give greater heat transfer as they force the fluid to flow in a more turbulent fashion around the piping. Square patterns are employed where high fouling is experienced and cleaning is more regular. * Baffle Design: baffles are used in shell and tube heat exchangers to direct fluid across the tube bundle.They run perpendicularly to the shell and hold the bundle, preventing the tubes from sagging over a long length. They can also prevent the tubes from vibrating. The most common type of baffle is the segmental baffle. The semicircular segmental baffles are oriented at 180 degrees to the adjacent baffles forcing the f luid to flow upward and downwards between the tube bundle. Baffle spacing is of large thermodynamic concern when designing shell and tube heat exchangers. Baffles must be spaced with consideration for the conversion of pressure drop and heat transfer.For thermo economic optimization it is suggested that the baffles be spaced no closer than 20% of the shell’s inner diameter. Having baffles spaced too closely causes a greater pressure drop because of flow redirection. Consequently having the baffles spaced too far apart means that there may be cooler spots in the corners between baffles. It is also important to ensure the baffles are spaced close enough that the tubes do not sag. The other main type of baffle is the disc and donut baffle, which consists of two concentric baffles. An outer, wider baffle looks like a donut, whilst the inner baffle is shaped like a disk.This type of baffle forces the fluid to pass around each side of the disk then through the donut baffle generati ng a different type of fluid flow. Fixed tube liquid-cooled heat exchangers especially suitable for marine and harsh applications can be assembled with brass shells, copper tubes, brass baffles, and forged brass integral end hubs. [3] (See: Copper in heat exchangers). Conceptual diagram of a plate and frame heat exchanger. A single plate heat exchanger An interchangeable plate heat exchanger applied to the system of a swimming pool Plate heat exchanger Main article: Plate heat exchangerAnother type of heat exchanger is the plate heat exchanger. One is composed of multiple, thin, slightly separated plates that have very large surface areas and fluid flow passages for heat transfer. This stacked-plate arrangement can be more effective, in a given space, than the shell and tube heat exchanger. Advances in gasket and brazing technology have made the plate-type heat exchanger increasingly practical. In HVAC applications, large heat exchangers of this type are called plate-and-frame; when used in open loops, these heat exchangers are normally of the gasket type to allow periodic disassembly, cleaning, and inspection.There are many types of permanently bonded plate heat exchangers, such as dip-brazed, vacuum-brazed, and welded plate varieties, and they are often specified for closed-loop applications such as refrigeration. Plate heat exchangers also differ in the types of plates that are used, and in the configurations of those plates. Some plates may be stamped with â€Å"chevron†, dimpled, or other patterns, where others may have machined fins and/or grooves. Plate and shell heat exchanger A third type of heat exchanger is a plate and shell heat exchanger, which combines plate heat exchanger with shell and tube heat exchanger technologies.The heart of the heat exchanger contains a fully welded circular plate pack made by pressing and cutting round plates and welding them together. Nozzles carry flow in and out of the platepack (the ‘Plate side' flowpat h). The fully welded platepack is assembled into an outer shell that creates a second flowpath ( the ‘Shell side'). Plate and shell technology offers high heat transfer, high pressure, high operating temperature, compact size, low fouling and close approach temperature. In particular, it does completely without gaskets, which provides security against leakage at high pressures and temperatures.Adiabatic wheel heat exchanger A fourth type of heat exchanger uses an intermediate fluid or solid store to hold heat, which is then moved to the other side of the heat exchanger to be released. Two examples of this are adiabatic wheels, which consist of a large wheel with fine threads rotating through the hot and cold fluids, and fluid heat exchangers. Plate fin heat exchanger Main article: Plate fin heat exchanger This type of heat exchanger uses â€Å"sandwiched† passages containing fins to increase the effectiveness of the unit.The designs include crossflow and counterflow cou pled with various fin configurations such as straight fins, offset fins and wavy fins. Plate and fin heat exchangers are usually made of aluminium alloys, which provide high heat transfer efficiency. The material enables the system to operate at a lower temperature and reduce the weight of the equipment. Plate and fin heat exchangers are mostly used for low temperature services such as natural gas, helium and oxygen liquefaction plants, air separation plants and transport industries such as motor and aircraft engines. Advantages of plate and fin heat exchangers: High heat transfer efficiency especially in gas treatment * Larger heat transfer area * Approximately 5 times lighter in weight than that of shell and tube heat exchanger. * Able to withstand high pressure Disadvantages of plate and fin heat exchangers: * Might cause clogging as the pathways are very narrow * Difficult to clean the pathways * Aluminum alloys are susceptible to Mercury Liquid Embrittlement Failure Pillow plat e heat exchanger A pillow plate exchanger is commonly used in the dairy industry for cooling milk in large direct-expansion stainless steel bulk tanks.The pillow plate allows for cooling across nearly the entire surface area of the tank, without gaps that would occur between pipes welded to the exterior of the tank. The pillow plate is constructed using a thin sheet of metal spot-welded to the surface of another thicker sheet of metal. The thin plate is welded in a regular pattern of dots or with a serpentine pattern of weld lines. After welding the enclosed space is pressurized with sufficient force to cause the thin metal to bulge out around the welds, providing a space for heat exchanger liquids to flow, and creating a characteristic appearance of a swelled pillow formed out of metal.Fluid heat exchangers This is a heat exchanger with a gas passing upwards through a shower of fluid (often water), and the fluid is then taken elsewhere before being cooled. This is commonly used for cooling gases whilst also removing certain impurities, thus solving two problems at once. It is widely used in espresso machines as an energy-saving method of cooling super-heated water to use in the extraction of espresso. Waste heat recovery units A Waste Heat Recovery Unit (WHRU) is a heat exchanger that recovers heat from a hot gas stream while transferring it to a working medium, typically water or oils.The hot gas stream can be the exhaust gas from a gas turbine or a diesel engine or a waste gas from industry or refinery. They can also be integrated into a heatcatcher system that allows an ORC[further explanation needed] generator to produce waste heat to power. Dynamic scraped surface heat exchanger Another type of heat exchanger is called â€Å"(dynamic) scraped surface heat exchanger†. This is mainly used for heating or cooling with high-viscosity products, crystallization processes, evaporation and high-fouling applications.Long running times are achieved due to th e continuous scraping of the surface, thus avoiding fouling and achieving a sustainable heat transfer rate during the process. Phase-change heat exchangers Typical kettle reboiler used for industrial distillation towers Typical water-cooled surface condenser In addition to heating up or cooling down fluids in just a single phase, heat exchangers can be used either to heat a liquid to evaporate (or boil) it or used as condensers to cool a vapor and condense it to a liquid. In chemical plants and refineries, reboilers used to heat incoming feed for distillation towers are often heat exchangers. 4][5] Distillation set-ups typically use condensers to condense distillate vapors back into liquid. Power plants that use steam-driven turbines commonly use heat exchangers to boil water into steam. Heat exchangers or similar units for producing steam from water are often called boilers or steam generators. In the nuclear power plants called pressurized water reactors, special large heat exchan gers pass heat from the primary (reactor plant) system to the secondary (steam plant) system, producing steam from water in the process. These are called steam generators.All fossil-fueled and nuclear power plants using steam-driven turbines have surface condensers to convert the exhaust steam from the turbines into condensate (water) for re-use. [6][7] To conserve energy and cooling capacity in chemical and other plants, regenerative heat exchangers can transfer heat from a stream that must be cooled to another stream that must be heated, such as distillate cooling and reboiler feed pre-heating. This term can also refer to heat exchangers that contain a material within their structure that has a change of phase.This is usually a solid to liquid phase due to the small volume difference between these states. This change of phase effectively acts as a buffer because it occurs at a constant temperature but still allows for the heat exchanger to accept additional heat. One example where this has been investigated is for use in high power aircraft electronics. Direct contact heat exchangers Direct contact heat exchangers involve heat transfer between hot and cold streams of two phases in the absence of a separating wall. [8] Thus such heat exchangers can be classified as: * Gas – liquid * Immiscible liquid – liquid Solid-liquid or solid – gas Most direct contact heat exchangers fall under the Gas- Liquid category, where heat is transferred between a gas and liquid in the form of drops, films or sprays. [2] Such types of heat exchangers are used predominantly in air conditioning, humidification, industrial hot water heating, water cooling and condensing plants. [9] Phases[10]| Continuous phase| Driving force| Change of phase| Examples| Gas – Liquid| Gas| Gravity| No| Spray columns, packed columns| | | | Yes| Cooling towers, falling droplet evaporators| | | Forced| No| Spray coolers/quenchers| | Liquid flow| Yes| Spray condensers/evaporati on, jet condensers| | Liquid| Gravity| No| Bubble columns, perforated tray columns| | | | Yes| Bubble column condensers| | | Forced| No| Gas spargers| | | Gas flow| Yes| Direct contact evaporators, submerged combustion| HVAC air coils One of the widest uses of heat exchangers is for air conditioning of buildings and vehicles. This class of heat exchangers is commonly called air coils, or just coils due to their often-serpentine internal tubing. Liquid-to-air, or air-to-liquid HVAC coils are typically of modified crossflow arrangement. In vehicles, heat coils are often called heater cores.On the liquid side of these heat exchangers, the common fluids are water, a water-glycol solution, steam, or a refrigerant. For heating coils, hot water and steam are the most common, and this heated fluid is supplied by boilers, for example. For cooling coils, chilled water and refrigerant are most common. Chilled water is supplied from a chiller that is potentially located very far away, but refri gerant must come from a nearby condensing unit. When a refrigerant is used, the cooling coil is the evaporator in the vapor-compression refrigeration cycle. HVAC coils that use this direct-expansion of refrigerants are commonly called DX coils.Some DX coils are â€Å"microchannel† type. [11] On the air side of HVAC coils a significant difference exists between those used for heating, and those for cooling. Due to psychrometrics, air that is cooled often has moisture condensing out of it, except with extremely dry air flows. Heating some air increases that airflow's capacity to hold water. So heating coils need not consider moisture condensation on their air-side, but cooling coils must be adequately designed and selected to handle their particular latent (moisture) as well as the sensible (cooling) loads.The water that is removed is called condensate. For many climates, water or steam HVAC coils can be exposed to freezing conditions. Because water expands upon freezing, these somewhat expensive and difficult to replace thin-walled heat exchangers can easily be damaged or destroyed by just one freeze. As such, freeze protection of coils is a major concern of HVAC designers, installers, and operators. The introduction of indentations placed within the heat exchange fins controlled condensation, allowing water molecules to remain in the cooled air.This invention allowed for refrigeration without icing of the cooling mechanism. [12] The heat exchangers in direct-combustion furnaces, typical in many residences, are not ‘coils'. They are, instead, gas-to-air heat exchangers that are typically made of stamped steel sheet metal. The combustion products pass on one side of these heat exchangers, and air to heat on the other. A cracked heat exchanger is therefore a dangerous situation that requires immediate attention because combustion products may enter living space. Spiral heat exchangers Schematic drawing of a spiral heat exchanger.A spiral heat exchang er (SHE), may refer to a helical (coiled) tube configuration, more generally, the term refers to a pair of flat surfaces that are coiled to form the two channels in a counter-flow arrangement. Each of the two channels has one long curved path. A pair of fluid ports are connected tangentially to the outer arms of the spiral, and axial ports are common, but optional. [13] The main advantage of the SHE is its highly efficient use of space. This attribute is often leveraged and partially reallocated to gain other improvements in performance, according to well known tradeoffs in heat exchanger design. A notable tradeoff is capital cost vs operating cost. ) A compact SHE may be used to have a smaller footprint and thus lower all-around capital costs, or an over-sized SHE may be used to have less pressure drop, less pumping energy, higher thermal efficiency, and lower energy costs. Construction The distance between the sheets in the spiral channels are maintained by using spacer studs that were welded prior to rolling. Once the main spiral pack has been rolled, alternate top and bottom edges are welded and each end closed by a gasketed flat or conical cover bolted to the body.This ensures no mixing of the two fluids occurs. Any leakage is from the periphery cover to the atmosphere, or to a passage that contains the same fluid. [14] Self cleaning SHEs are often used in the heating of fluids that contain solids and thus tend to foul the inside of the heat exchanger. The low pressure drop lets the SHE handle fouling more easily. The SHE uses a â€Å"self cleaning† mechanism, whereby fouled surfaces cause a localized increase in fluid velocity, thus increasing the drag (or fluid friction) on the fouled surface, thus helping to dislodge the blockage and keep the heat exchanger clean. The internal walls that make up the heat transfer surface are often rather thick, which makes the SHE very robust, and able to last a long time in demanding environments. † They are also easily cleaned, opening out like an oven where any build up of foulant can be removed by pressure washing. Self-Cleaning Water filters are used to keep the system clean and running without the need to shut down or replace cartridges and bags. Flow arrangements Concurrent and countercurrent flow. There are three main types of flows in a spiral heat exchanger: 1. Counter-current Flow: Fluids flow in opposite directions.These are used for liquid-liquid, condensing and gas cooling applications. Units are usually mounted vertically when condensing vapour and mounted horizontally when handling high concentrations of solids. 2. Spiral Flow/Cross Flow: One fluid is in spiral flow and the other in a cross flow. Spiral flow passages are welded at each side for this type of spiral heat exchanger. This type of flow is suitable for handling low density gas, which passes through the cross flow, avoiding pressure loss. It can be used for liquid-liquid applications if one liquid has a cons iderably greater flow rate than the other. . Distributed Vapour/Spiral flow: This design is that of a condenser, and is usually mounted vertically. It is designed to cater for the sub-cooling of both condensate and non-condensables. The coolant moves in a spiral and leaves via the top. Hot gases that enter leave as condensate via the bottom outlet. Applications The SHE is good for applications such as pasteurization, digester heating, heat recovery, pre-heating (see: recuperator), and effluent cooling. For sludge treatment, SHEs are generally smaller than other types of heat exchangers. [citation needed] SelectionDue to the many variables involved, selecting optimal heat exchangers is challenging. Hand calculations are possible, but many iterations are typically needed. As such, heat exchangers are most often selected via computer programs, either by system designers, who are typically engineers, or by equipment vendors. To select an appropriate heat exchanger, the system designers (or equipment vendors) would firstly consider the design limitations for each heat exchanger type. Though cost is often the primary criterion, several other selection criteria are important: * High/low pressure limits * Thermal performance Temperature ranges * Product mix (liquid/liquid, particulates or high-solids liquid) * Pressure drops across the exchanger * Fluid flow capacity * Cleanability, maintenance and repair * Materials required for construction * Ability and ease of future expansion * Material selection, such as copper, aluminum, carbon steel, stainless steel, nickel alloys, and titanium. Small-diameter coil technologies are becoming more popular in modern air conditioning and refrigeration systems because they have better rates of heat transfer than conventional sized condenser and evaporator coils with round copper tubes and aluminium or opper fin that have been the standard in the HVAC industry. Small diameter coils can withstand the higher pressures required by the new generation of environmentally friendlier refrigerants. Two small diameter coil technologies are currently available for air conditioning and refrigeration products: copper microgroove[15] and brazed aluminium microchannel. [16] Choosing the right heat exchanger (HX) requires some knowledge of the different heat exchanger types, as well as the environment where the unit must operate.Typically in the manufacturing industry, several differing types of heat exchangers are used for just the one process or system to derive the final product. For example, a kettle HX for pre-heating, a double pipe HX for the ‘carrier’ fluid and a plate and frame HX for final cooling. With sufficient knowledge of heat exchanger types and operating requirements, an appropriate selection can be made to optimise the process. [17] Monitoring and maintenance Online monitoring of commercial heat exchangers is done by tracking the overall heat transfer coefficient. The overall heat transfer coeffi cient tends to decline over time due to fouling.U=Q/A? Tlm By periodically calculating the overall heat transfer coefficient from exchanger flow rates and temperatures, the owner of the heat exchanger can estimate when cleaning the heat exchanger is economically attractive. Integrity inspection of plate and tubular heat exchanger can be tested in situ by the conductivity or helium gas methods. These methods confirm the integrity of the plates or tubes to prevent any cross contamination and the condition of the gaskets. Mechanical integrity monitoring of heat exchanger tubes may be conducted through Nondestructive methods such as eddy current testing.Fouling Main article: Fouling A heat exchanger in a steam power station contaminated with macrofouling. Fouling occurs when impurities deposit on the heat exchange surface. Deposition of these impurities can decrease heat transfer effectiveness significantly over time and are caused by: * Low wall shear stress * Low fluid velocities * Hi gh fluid velocities * Reaction product solid precipitation * Precipitation of dissolved impurities due to elevated wall temperatures The rate of heat exchanger fouling is determined by the rate of particle deposition less re-entrainment/suppression.This model was originally proposed in 1959 by Kern and Seaton. Crude Oil Exchanger Fouling. In commercial crude oil refining, crude oil is heated from 21  °C to 343  °C prior to entering the distillation column. A series of shell and tube heat exchangers typically exchange heat between crude oil and other oil streams to heat the crude to 260  °C prior to heating in a furnace. Fouling occurs on the crude side of these exchangers due to asphaltene insolubility. The nature of asphaltene solubility in crude oil was successfully modeled by Wiehe and Kennedy. 18] The precipitation of insoluble asphaltenes in crude preheat trains has been successfully modeled as a first order reaction by Ebert and Panchal[19] who expanded on the work of Ke rn and Seaton. Cooling Water Fouling. Cooling water systems are susceptible to fouling. Cooling water typically has a high total dissolved solids content and suspended colloidal solids. Localized precipitation of dissolved solids occurs at the heat exchange surface due to wall temperatures higher than bulk fluid temperature. Low fluid velocities (less than 3  ft/s) allow suspended solids to settle on the heat exchange surface.Cooling water is typically on the tube side of a shell and tube exchanger because it's easy to clean. To prevent fouling, designers typically ensure that cooling water velocity is greater than 0. 9 m/s and bulk fluid temperature is maintained less than 60  °C. Other approaches to control fouling control combine the â€Å"blind† application of biocides and anti-scale chemicals with periodic lab testing. Maintenance Plate heat exchangers must be disassembled and cleaned periodically. Tubular heat exchangers can be cleaned by such methods as acid cleani ng, sandblasting, high-pressure water jet, bullet cleaning, or drill rods.In large-scale cooling water systems for heat exchangers, water treatment such as purification, addition of chemicals, and testing, is used to minimize fouling of the heat exchange equipment. Other water treatment is also used in steam systems for power plants, etc. to minimize fouling and corrosion of the heat exchange and other equipment. A variety of companies have started using water borne oscillations technology to prevent biofouling. Without the use of chemicals, this type of technology has helped in providing a low-pressure drop in heat exchangers. In nature HumansThe human nasal passages serve as a heat exchanger, which warms air being inhaled and cools air being exhaled. You can demonstrate its effectiveness by putting your hand in front of your face and exhaling, first through your nose and then through your mouth. Air exhaled through your nose is substantially cooler. [20][21] In species that have e xternal testes (such as humans), the artery to the testis is surrounded by a mesh of veins called the pampiniform plexus. This cools the blood heading to the testis, while reheating the returning blood. Birds, fish, marine mammalsCountercurrent exchange conservation circuit Further information: Countercurrent exchange in biological systems â€Å"Countercurrent† heat exchangers occur naturally in the circulation system of fish, whales and other marine mammals. Arteries to the skin carrying warm blood are intertwined with veins from the skin carrying cold blood, causing the warm arterial blood to exchange heat with the cold venous blood. This reduces the overall heat loss in cold waters. Heat exchangers are also present in the tongue of baleen whales as large volumes of water flow through their mouths. 22][23] Wading birds use a similar system to limit heat losses from their body through their legs into the water. Carotid rete The carotid rete is a counter-current heat exchangi ng organ in some ungulates. The blood ascending the carotid arteries on its way to the brain, flows via a network of vessels where heat is discharged to the veins of cooler blood descending from the nasal passages. The carotid rete allows Thomson's gazelle to maintain its brain almost 3 °C cooler than the rest of the body, and therefore aids in tolerating bursts in metabolic heat roduction such as associated with outrunning cheetahs (during which the body temperature exceeds the maximum temperature at which the brain could function). [24] In industry Heat exchangers are widely used in industry both for cooling and heating large scale industrial processes. The type and size of heat exchanger used can be tailored to suit a process depending on the type of fluid, its phase, temperature, density, viscosity, pressures, chemical composition and various other thermodynamic properties.In many industrial processes there is waste of energy or a heat stream that is being exhausted, heat exch angers can be used to recover this heat and put it to use by heating a different stream in the process. This practice saves a lot of money in industry, as the heat supplied to other streams from the heat exchangers would otherwise come from an external source that is more expensive and more harmful to the environment. Heat exchangers are used in many industries, including: * Waste water treatment Refrigeration * Wine and beer making * Petroleum refining In waste water treatment, heat exchangers play a vital role in maintaining optimal temperatures within anaerobic digesters to promote the growth of microbes that remove pollutants. Common types of heat exchangers used in this application are the double pipe heat exchanger as well as the plate and frame heat exchanger. In aircraft In commercial aircraft heat exchangers are used to take heat from the engine's oil system to heat cold fuel. 25] This improves fuel efficiency, as well as reduces the possibility of water entrapped in the fu el freezing in components. [26] Early 2008, a Boeing 777 flying as British Airways Flight 38 crashed just short of the runway. In an early-2009 Boeing-update sent to aircraft operators, the problem was identified as specific to the Rolls-Royce engine oil-fuel flow heat exchangers. [26] Other heat exchangers, or Boeing 777 aircraft powered by GE or Pratt and Whitney engines, were not affected by the problem. [26]