Relationship between entrepreneruship

Discuss the relationship between entrepreneurship, innovation and economic development. What role do creativity and problem solving play in this relationship? Refer to both theories and examples from the business world to support your discussion. Since last century, entrepreneurship and innovation have been heavily discussed. Entrepreneurs create new business and provide the Job opportunities to society as well as promote the economic development.However, with the increasing global economic competition, normal entrepreneurship becomes less competitiveness, government committed to develop innovative entrepreneurship in recent years Cukier, 2006). Therefore, the relationship between innovation and entrepreneurship becomes one of the most significant topics in the business field. Economists do a large number of researches to explore the connection between entrepreneurship and innovation as well as the position they related in economic development.During the process of exploring, a consi derable amount of definitions are put forward by experts based on their research knowledge and the analysis of entrepreneurs developed in recent decades. This essay will list the definitions put forward by ifferent economists, then support the ideas that innovation, entrepreneurship and economic development are deeply connected and interacted. Finally, combine with the experience of university group entrepreneurship project, attempt to explain importance role that the creativity and problem solving played in this process.Definition of the innovation and entrepreneurship is colored by different economists according to their observation, research and knowledge. From the innovation perspective, one of the most important definitions is related to the Joseph Schumpeter, a pioneer of the innovation management, who put forward a theory ccording to his early studying. Schumpeter (1934) defines innovation as the combination of new goods, new methods of production, the opening of new markets, the conquest of new sources of supply and the carrying out of a new organization of any industry.Jocabs (2007) list several definitions in her article based on her study: Peter Drucker believed that innovation is a process that change and creates a new dimension of performance; Jose Campos, director of the Center for Rapid Innovation considered that innovation is kind of the ability to which can deliver value to a ustomer; David Schmittlen has a deeper opinion, he believed that product is not the only factor innovation related, the processes and approaches to the marketplace is where innovation occur.All these definitions have their limitations and emphasizes, but with the change of the social and economic environment, innovation may have a wider meaning such as Regins Cabral mentioned in his opinion which connect the innovation with the network. From the entrepreneurship perspective, the word â€Å"entrepreneurship† related to many meanings. In the second volume of The Isol ated State (1850) provided by Johann von Thunen, he defined the entrepreneurship as a way which earns profits after cutting over all the expenses such as payments to capital, labor and insurance, and needs to take unpredictable risk.Risk part in this theory was supported by Frank Knight, and he believed the only risk that leads to profit is a unique uncertainty resulting from an exercise of ultimate responsibility which in its very nature cannot be insured nor capitalized nor salaried† (Knight, 1921). Joseph Schumpeter is one of the most influential economists in the history. His theory of entrepreneurship heavily ased on his innovation theory and roughly experienced three stages. In the early stage of his studying, his notion of entrepreneurship emphasized newness and innovation, and aimed at encouraging economic development (1928).Later, with more research had been done; Schumpeter gave up the risk-taking, one of the characteristics of entrepreneurship which is agreed by von Thunen and Knight. In the 1940s, Schumpeter's work on entrepreneurship became broader. In this period, he was no longer limited by original theory, but discussed several types of the entrepreneurs and extended the meaning of entrepreneurship. Another very important definition in history was made by Ludwing von Mises and Friedrich von Hayek.Ludwing von Mises (1963) has different ideas with Schumpeter by stated entrepreneurship involves anticipations of uncertain events rather than innovations. The reason why he said that is because there is a belief that entrepreneur gain profits by correctly anticipating the market and providing the products to customer before the competition driven by a desire for money. The definitions of the innovation and entrepreneurship are of variety, but viewpoint about the relationship between them is quite similar.Peter Drucker mentioned that entrepreneurship and innovation is companion terms, innovation is a tool that entrepreneurship can take advantage of. From the perspective of entrepreneurship, Schumpeter (1928, 1939) mentions that entrepreneurship as the source of the innovation and innovation as the engine of economic development, which emphasize the many attributes and motivation of the entrepreneur. This is an idea which was a leading though, many economist after Schumpeter agree with this idea.From the innovation perspective, economists such as Pretorius and Millard strongly supported he theory which considered a significant innovation is usually the basis of the successful entrepreneurial venture. Consider the opinions above all; innovation and entrepreneurship are deeply interacting with each other. For example, McDonalds' analyzed the marketplace and consumers' need; design the new production lines and new methods trained staff. According to the definitions listed before, due to McDonald's creative new marketplace and consumer, and combine with the improving of the management, it is entrepreneurship.In addition, cause t he increasing global economic competition, government as well as individual oncentrate more on the innovative entrepreneurship. Evidences shows that government of The European Union, United States and countries in Asia all published policies to support, lead and value the innovative entrepreneurship due to the large contributions it comes in the future (Cukier 2006). The relationship between innovation and economic growth is closely connected and the relationship between them is mutual. On the one hand, innovation is a source of economic development.According to the Schumpeter (1942), who considered the innovation activity of entrepreneur of a process which provide a creative ‘destruction rocess' by causing sustain disturbances to an economic system in equilibrium, and create new opportunities to economic. It means that innovation encourages the changes of economy system and creates opportunities which are beneficial to economic development. Peter Drucker is one of the influen tial economists, stated that the innovation is the central issue in economic prosperity.He listed five principles of innovation and the first one is the innovation beginning with analysis of the opportunities, starting from the small entrepreneurs and aiming at market leadership. In addition, a large amount of the empirical work showed evidence to ndicate that the level of the technological innovation do large contribute to economic performance, both at the companies and industry aspects. Economic development also creates a suitable environment for innovation. A high level economic development is conducive to innovation.The Global Innovative Index, which is established by INSEAD Business School and World Business, it measures the world's best and worst performing economies with measurement of innovation. It also evaluate the nation's strengths and weaknesses in their economic development environment especially policies and practices related to innovation. United States, Israel and S witzerland are top three countries. All of these countries have a common strength which is the positive environment for innovation, especially in United States. Government policies are firmly support the development of innovation.For example, Silicon Valley in California, which is the typical example to indicate government policies are essential fact to stimulate innovation. Similar to innovation and economic development, it is widely believed that entrepreneurship and economic development influence each other deeply. Entrepreneurship is beneficial for economic development. Entrepreneurship in the early twentieth century, according to the statement of Cipolla (1981) and Lazonick (1991), plays an essential role in the long-term economic. The contribution to the growth of economy was attributed to entrepreneurs.They seek for new opportunities, diversified the productions and develop a new market. With the change of the economic environment, in middle of the twentieth century, entrepre neurship lost its superiority, however, in the recent decades, with the revolution of the knowledge and technologies; it encouraged the development of entrepreneurship thinking Oovanovic, 1982; Audretsch, 1995). In the perspective of the economic development, entrepreneurs not only create new market but also provide the new ideas to marketplace, and promote the economic growth through a process of fierce competition.However, not all kinds of entrepreneurship are effective for economic development. According to the research by Global Entrepreneurship Monitor (GEM), there are two kinds of entrepreneurship. One is â€Å"necessity entrepreneurship† and the other is â€Å"opportunity entrepreneurship†. Necessity entrepreneurship nas a negative ettect on economic development. A typical example of it is that after the fall of Berlin Wall, any workers in socialist countries found them had no options but work for themselves, this necessity entrepreneurship caused several years of negative GDP growth.On the contrary, opportunity entrepreneurship could lead to an economic development. Based on the statistics collected from the eleven countries, entrepreneurship which has multiple opportunities could lead to economic development (Asc, 2006). For one country, due to the fact that different countries have different economic development level, government should fgure out what kind the entrepreneurship is and develop opportunity entrepreneurship. For individuals, it is essential to analyze the opportunities and potential market before starting an enterprise.Creativity and problem solving cannot be ignored in the relationship among the entrepreneurship, innovation and economic development. Creativity is an essential characteristic in the problem solving process and it is usually defined as a process though which invention occurs something new comes into existence (Herbert et al. , 1999), and they also regard creativity as the starting point of the innovation. Ana lyzing creativity from the entrepreneurship direction, in past several decades, esearchers did a great deal studies to explore the position of creativity in the process of the development of entrepreneurship.Shaw (1996) mentions that opportunity is the first step that entrepreneurship pursued and creativity is the key point to identify business opportunity (Hills and Shrader 1998). Venture capitalist Vinod Khosla also said that no problem means no opportunity, no solution and no company. Therefore, due to the significant position in the entrepreneurial process, creativity is the soul of entrepreneurship (Morris and Kuratko, 2002). Since nnovation, entrepreneurship and economic development is closely connected, creativity is the fundamental of the whole relationship.In university, Entrepreneurship and Business is one of the most important modules which students need to major in. group project is the significant concept to help students to understand entrepreneurship and essential pos ition that creativity in problem solving process. Kirkham, Mosey and Binks (2009) state that the process of problem can be three steps: define, discover and determine. The project started from defines a problem, and then use the creativity thinking to discovery a large amount of olutions. Finally, determine the most effective solution.This process is what the entrepreneurship usually does in their commercial field. Identifying a problem in business, then analyze the business opportunities and use creativity thinking to find potential solutions in the marketplace, eventually decide the most effective way to establish an enterprise. To sum up, entrepreneurship, innovation and economic development are deeply connected. Definition of innovation and entrepreneurship various from people to people, but all these leads to a conclusion that innovation and entrepreneurship are ompanies terms.Innovation is the basis of the entrepreneurship and entrepreneurship as the source of innovation. In a ddition, in the process of economic development, all evidences show innovation promotes the economic development and an environment which support by government policies encourages the innovation as well. Entrepreneurship benefit to economic development, although only opportunity entrepreneurship has a positive effect to economy. Though the analysis of creativity and problem solving, recognize the importance role it play in the economic development. words: 1896

Controversy Behind Qatar 2022 Bid

Qatar 2022 On 2 December 2010 it was announced that Qatar would host the 2022 FIFA World Cup, after the FIFA Executive Committee voted in a secret ballot in Zurich. The government of Qatar’s successful proposal bid defeated four other candidates to stage the 2022 edition of the world’s greatest sporting event: Australia, Korea Republic, Japan and the United States of America. Qatar, with a population of 1. 69 million people will be the first Arab state to host the World Cup. Consequently, Qatar is the smallest nation, both by relative population and by area, ever to have been awarded the tournament hosting privilege. The Qatar bid was emphasized as the only one representing the Arab World (which has never hosted a World Cup prior) and positioned their bid as an opportunity to bridge the gap between the Arab World and the West. Their hosting of the 2006 Asian Games as well as the 2011 Asian Cup proved to legitimize their capabilities of hosting the tournament. Further, its superior financial capabilities were evident in their proposals for new stadia and infrastructure. While the decision on 2 December 2010 brought delight to Qatar, it inversely brought concern and controversy in the West. A number of rival candidates, western groups and media outlets have expressed concern over the suitability of Qatar to host the event, with regard to climatic conditions, interpretations of human rights, press freedom and allegations of corruption. Climate: Winter World Cup? The World Cup is traditionally held in the northern hemisphere’s summer. During this season in Qatar, the temperature can get to 50  °C  (122  Ã‚ °F). The Qatar bid’s chief executive, Hassan al-Thawadi has attempted to quell fears of an unbearable environment by stating â€Å"heat is not and will not be an issue† and that the 2022 World Cup would benefit from â€Å"state-of-the-art air cooling technologies. † The Qatar 2022 Bid’s official site explains this: â€Å"Each of the five stadiums will harness the power of the sun’s rays to provide a cool environment for players and fans by converting solar energy into electricity that will then be used to cool both fans and players at the stadiums. When games are not taking place, the solar installations at the stadia will export energy onto the power grid. During matches, the stadia will draw energy from the grid. This is the basis for the stadiums’ carbon-neutrality. Along with the stadiums, we plan to make the cooling technologies we’ve developed available to other countries in hot climates, so that they too can host major sporting events. † This method of cooling techniques is theoretically able to reduce temperatures from 50 to 27 degrees Celsius. The bidding committee also proposes to use such cooling technologies in fan-zones, training pitches and walkways between metro stations and stadiums. However, the architect in charge of one of the venues has abandoned their project claiming that a more old-fashioned solution would be cheaper and better. Leading firm Populous, which is designing the Sports City stadium in Doha, is trying to persuade Qatari organizers to scrap plans to have air conditioning at the venue. Populous director John Barrow said the system is too expensive and â€Å"notoriously unsustainable† for the environment when used on a large scale. Given the debate on the subject, a proposal of hosting a â€Å"Winter World Cup† has arisen. Backed by the likes of Blatter and Platini, the proposal suggests for the tournament to be held in January of 2022, rather than the summer. Blatter has told reporters â€Å"Personally, now that the decision has been taken [to have the tournament in Qatar], we must play at the most adequate period to have a successful World Cup and to have a successful World Cup we have to do it when it is best for the actors which means winter. † However, Mr. Blatter has failed to provide a solution on the effect it would have on European domestic leagues which operate in this period. There is nothing in FIFA’s rules to prevent a host changing the time of year when a World Cup is played. It is only tradition that dictates this. And the FIFA executive committee has the authority to change any aspect of the World Cup after the decision is made. Worker’s Conditions Given its lack of sporting infrastructure, the Gulf state must build nine football stadiums in the next ten years- and they’ll be using primarily migrant labor (over 90% of Qatar’s workforce is made up of foreign migrant workers). Trade union activists are now lobbying FIFA to highlight what they say are poor working conditions in Qatar. International trade unionists say FIFA has the power to impose decent working standards on Qatar and will campaign for the tournament to be moved unless FIFA presses for better conditions. If Qatar is unable to support the tournament on its own, Secretary-General Jerome Valcke has suggested the tournament be shared with neighboring states, such as Bahrain and the United Arab Emirates. Alcohol and Homosexuality Qatar is not a dry country. Alcohol can currently be consumed legally in a few clubs, bars, certain hotel restaurants, and the Pearl Island by showing your passport for reporting. Hassan Abdulla al Thawadi, chief executive of the Qatar 2022 World Cup bid, said the Muslim state would also permit alcohol consumption during the event. Specific fan-zones will be established where alcohol can be bought. Though legal with a permit, drinking in public is not permitted as Qatar's legal system is based on  Sharia  law. The selection of Qatar as hosts attracted controversy, as  homosexuality  is illegal in Qatar. FIFA President  Sepp Blatter  stated that â€Å"we (FIFA) don't want any discrimination. What we want to do is open this game to everybody, and to open it to all cultures, and this is what we are doing in 2022. Corruption: Bribery Scandal Six members of Fifa’s executive committee — a quarter of the membership – were accused by Lord Treisman (Chairman of England’s bid) of â€Å"improper and unethical behaviour† with two members, Issa Hayatou, of Cameroon, and Jacques Anouma, of Ivory Coast, alleged to received $1. 5 million each in bribes from the Qatar 2022 bid in exchange for their votes. The bribery allegations against Qatar were made in evidence from  The Sunday Times  and published by the committee. As a result, in November 2010, two ExCo members,  Reynald Temarii  and  Amos Adamu, were banned for one and three years respectively. Temarii was also fined 5,000 Swiss Francs, while Adamu was fined 10,000 Swiss Francs. More corruption allegations emerged in the summer of 2011. In May, ExCo member Chuck Blazer claimed fellow members Mohammed Bin Hammam and Jack Warner offered bribes for votes in the upcoming presidential election. As a result of this scandal, Bin Hammam stood down from the June 2011 presidential election and FIFA later suspended both he and Jack Warner. Sepp Blatter stood unopposed and won the election with 186 out of 203 votes. Bin Hammam’s suspension had been met with widespread anger in the Middle East- He was subsequently banned for life in July. Warner responded to his suspension by exposing an email by Valcke in which the Secretary-General suggested Qatar had â€Å"bought† the right to host 2022 tournament. Valcke defended his statement, insisting he was referring to Qatar using financial muscle to lobby legitimately for votes. â€Å"They were a candidate with a very important budget and used it to heavily promote their bid all around the world in a very efficient manner,† he said. â€Å"I have made no reference to any purchase of votes or similar unethical behaviour. Qatar 2022's bid team said they â€Å"categorically deny† any wrongdoing, and asked for clarification from FIFA on the meaning of the Valcke e-mail. Nevertheless, the scandal has raised concerns over $10 billion of investment and development contracts related to stadiums and hotels for the World Cup in Qatar. Possibility of a Re-Vote Given the developments in corruption and bribery scandals, as well as questions concerning the Qatar’s capabilities of hosting the tournament effectively, there is a ground swell of popular support to re-hold the 2022 vote won by Qatar. Blatter has said that a FIFA inquiry into persistent and increasingly detailed claims of corruption could lead to the Executive Committee (ExCo) making the unprecedented move of rerunning the vote. Blatter also conceded that support for re-running the vote was â€Å"circulating around the world†. Such a move would be a monumental embarrassment to FIFA but that has to now be balanced with the equivalent embarrassment of more allegations leaking out.

Firearms For Security

Among small arms, the RIFLE and shotgun are both long-barreled weapons used for long-range shooting; the PISTOL has a shorter barrel and is accurate only at relatively short ranges. The REVOLVER, usually a pistol, has a revolving cylinder that allows repeat firing. The precise origin of firearms is unknown, although they were certainly in use by the early 14th century and were fairly common in Europe by mid-century. These early guns were little more than large-caliber tubes of wrought iron or cast bronze, closed at one end and loaded by placing GUNPOWDER and projectile in the muzzle, or open end. They were fired by touching a burning wick, or match, to the powder at a â€Å"touch-hole† bored in the top of the barrel. To make certain that the powder would ignite, a recess was incised around the hole into which additional powder–the primer–was pouredSmoothbore muskets were notorious for their short range and poor accuracy. Seeking to improve performance, gun makers etched spiral grooves, or rifling, inside the musket barrel. The grooving imparted a spin to the projectile, thus stabilizing its trajectory. Rifles became popular with hunters in both Europe and America, but they were impractical for most military uses because they were difficult to load. In 1849 the French army captain Claude Minie invented the conical minie ball, which was easily dropped down the barrel of a rifled musket but expanded to engage the rifling when the weapon was fired. Rifles using expandable bullets had four times the range and accuracy of the smoothbore musket. Hunting is the stalking, pursuit, and killing of game animals or birds. Humans hunting for sport enjoy the excitement of these activities. Modern sport hunters may use the modern technology of a high-powered, telescopically aimed rifle or may approximate the conditions of their primitive ancestors and use a bow and arrow. They may also be assisted by animals such as dogs and horses. Humans have hunted for food for thousands of years. Hunting exclusively for sport, however, is a comparatively recent development. For both the North American Indian and the early colonists hunting provided a cheap and seemingly limitless food supply. As the eastern coast of the continent was settled, predators were eliminated because they posed a threat to domestic livestock. Forests were cleared for fuel and farming, and many species were depleted or disappeared. Eventually a series of reforms was enacted to save game throughout the United States. The time of year when game could be taken was limited. Licensing was required, with the funds raised from the sale of licenses going to support state game departments. The numbers of animals that one person could take in a season were also restricted. In addition, large parcels of land were set aside in the national park system in which hunting was prohibited. These measures have been effective in preserving wildlife resourcesHunting in the United States can be classified into one of five types: big game–bears, cougars, wolves, and the large ungulates such as deer, elk, antelope, moose, and wild sheep and goats; waterfowl–ducks and geese; upland game birds–turkeys, grouse, and pheasants; small game–squirrels and rabbit; and varmints–pest species unprotected by game laws. Hunters use shotguns when pursuing small game or birds in flight and use rifles for larger quarry. A hunter may either still hunt–sit and wait for game–or stalk the prey–approaching within shooting range undetected. In a drive, beaters alarm concealed animals, which, as they leave their hiding places, pass waiting hunters. Other less frequently used ways of taking game include bow and arrow, traps, spears, blowguns and boomerangs. In the United States about 16 million hunting licenses are purchased each year. The number of individuals who hunt is estimated to be slightly larger. Hunting in all it forms is a subject of controversy in the United States. Critics of hunting range from ANIMAL RIGHT activists–who oppose all hunting on principle–to those whose objections concern the competence and conduct of hunters. The latter claim that hunters violate game laws, trespass, kill livestock, damage property, and endanger human life with the careless use of firearms. Proponents of the sport maintain that hunters play a significant role in conservation and game control, as well as being a source of revenue for wildlife management services. They further contend that hunting is a safe activity because of safety classes, the wearing of â€Å"safety† orange (required in 41 states in the early 1990s), and the increasingly stringent licensing requirements mandated by state game departments.

Geography of Minnesota Essay Example | Topics and Well Written Essays - 250 words - 2

Geography of Minnesota - Essay Example This is supported by a survey that stated that over 70% of the population in the state is made up of immigrants. Some of the ethnic groups include African Americans brought as slaves to work in fields and construct the railways. After they attained their freedom they settled in Minnesota. Pacific Islanders came from the islands of Melanesia, Polynesia and Micronesia. They immigrated to Minnesota to seek employment in the fields and mines. American Indians are also referred to as Native Americans. This is because; they lived in America before its discovery by Christopher Columbus in 1492. Asian Americans are individuals of Asian descent. They immigrated to Minnesota in search of work, business and an education. Hispanics/Latinos are people of Latin descent and can trace their heritage back to Latin and South America. They immigrated to America and chose to stay in Minnesota due to its employment and business opportunities. All of these ethnic groups living and working together best illustrate spatial distribution. These ethnic groups are distributed across the state although some of them be liv e in specific areas (Hart, 2008). The first major wave of immigration was between 1860 and 1870. The first immigrants were from Germany. They were soon followed by the Norwegians who were referred to as Scandinavians. German immigrants composed the largest immigration group in Minnesota while the Norwegians only represented a small portion of the immigrants. Most of the German immigrants moved to farming areas within the state while the Scandinavians tended to settle in distinctive communities most of whom had relocated due to the potato famine they experienced between 1845 and 1852. The famine killed approximately a million people and in the process caused the immigration to the United

General psychology Essay Example | Topics and Well Written Essays - 500 words

General psychology - Essay Example However, if this stage is not successfully resolved the adolescent will continue to feel lost and unguided during adulthood. In contrast Marcia expanding on Erikson's theory of psychosocial development adding new stages that he believed adolescents chronologically progress through. Erikson believed that adolescents are heavily influenced by their peers and role models. These influences may hinder the development of the self. Marcia expanded Erikson's theory on psychosocial development. Marcia believed that adolescents experienced four identity statuses. Moreover Marcia believed that adolescents can be divided into categories of the egos identity statuses based upon their experiences. In contrast to Erikson Marcia believed that adolescents face another stage of identity development based upon their chronological development. This stage can be determined if the adolescent has experienced a crisis and formed a commitment. Adolescents that have achieved a crisis and formed a commitment are considered to have achieved an identity. Adolescents that do not perceive social norms and rules established by parents, teachers or other authority figures are deemed in the foreclosure stage.

An human rights be universal Essay Example | Topics and Well Written Essays - 2000 words

An human rights be universal - Essay Example And on the other, we have poor countries like India and Bangladesh where people do not even have enough to consume. How can these two different types of societies develop similar definitions of human rights or implement similar human right laws Human rights for someone in India may be having enough to eat and a place to keep oneself warm, while it has an entirely different meaning for someone in the United States. But human rights can and should be universal in nature as we shall discover from our discussion in this paper. All human rights are universal, indivisible and interdependent and interrelated. The international community must treat human rights globally in a fair and equal manner, on the same footing, and with the same emphasis. While the significance of national and regional particularities and various historical, cultural and religious backgrounds must be borne in mind, it is the duty of States, regardless of their political, economic and cultural systems, to promote and protect all human rights and fundamental freedoms. (United Nations 1993) But West may not be trying to integrate cultures into human rights definition for the sake of stamping its superiority but the main aim was to counter human rights violation in traditionalist Asian societies. The reality of an interdependent world has only recently dawned upon us and this has brought cultures and societies closer accentuating their differences. But these differences and the resulting furor over the concept of human rights being universal should not undermine the idea that world is interdependent and more closely linked than we previously assumed. The Declaration's provision of basic civil, political, economic, social, and cultural rights for "all members of the human family" has helped the world understand that we need "a common standard of achievement for all peoples and nations."(UN, 1948) The fact that United Nations chose to develop a new definition of human rights which it believes can be universally applies show its faith in human beings' "substantial capacity for moral understanding and progress." (Nickel: p. 41) The concept of human rights is not something new and can be traced back to philosophies of antiquity but it was in the last few centuries that they began taking their present form. However the inclusion of universalism in human rights is one concept which is not even a few decades old. Many events, declarations and globalization later we can summarize fundamental tenets of human rights law as follows: Every human being has certain rights that are inherent. Such rights can be enumerated or deduced; they are not earned or acquired but inhere in all people by virtue of their humanity alone. Every human being's basic rights are indefeasible or inalienable--that is, such rights can never be annulled or denied by outside parties or even by the affected individuals themselves. Conflicts between different rights must be resolved in accordance with just and impartial laws and procedures. (Sieghart, p.8) Human rights proponents offer some fair definitions of human rights w

Chronic Obstructive Pulmonary disease (COPD) as set out below Essay

Chronic Obstructive Pulmonary disease (COPD) as set out below - Essay Example Cor pulmonale, defined as hypertrophy, dilation, or dysfunction of the right ventricle due to pulmonary hypertension resulting form disorders of the respiratory system, also commonly occurs in patients with COPD (Missov ED, De Marco T 2000). There are evidences to support LTOT could significantly reduce mortality in patients with COPD and Cor pulmonale (Weitzenblum, E et al 1995, Croxton, TL 2006, Missov ED, De Marco T 2000, Zielinski, J 1998 ). Two randomized, controlled clinical trials have demonstrated the beneficial effects of LTOT in case of COPD and sever resting hypoxemia. They include the Nocturnal Oxygen therapy trial and the trials carried out by the Medical Research Council (Weitzenblum, E et al 1995, Barnett, M 2007, Croxton, TL 2006, Ruse, C 2008, Missov ED, De Marco T 2000). Both the trials indicated that oxygen therapy administered for at least 15 hours daily for patients with severe hypoxic COPD increased survival and in addition reduced polycythaemia and the progression of pulmonary hypertension (Barnett, M 2007). The main focus of LTOT is to improve the quality of life of the patients and thereby to increase their survival (Barnett, M 2007, Marti, S et al, 2006, Croxton, TL 2006). The criteria for the initiation of LTOT in the UK have been established based on the results of the 2 trials mentioned above (Barnett, M 2007, Zielinski, J 1998). The criteria as per the National clinical guidelines include patients with an arterial oxygen tension (PaO2) consistently at or below 7.3 kPa (55 mm Hg or less) when clinically stable. This threshold value of 55 mmHg indicates presence of severe hypoxemia which may have deleterious effects on pulmonary circulation, brain function etc (Atis, S et al 2001). Patients, who have a PaO2 consistently between 7.3 and 8.0 or 7.5 and 7.8 when clinically stable and if pulmonary hypertension (PAP >

M&M chocolate candy Essay Example | Topics and Well Written Essays - 3250 words

M&M chocolate candy - Essay Example The organization is well known for its confectionary brands like Mars bars, M&M’s, Milky Way bars, Snickers, Skittles, and Twix. Currently, the M&M’s chocolate candy is sold in over 100 countries worldwide. The most catching feature of this product is that its unique taste is appealable to people belonging to all age groups. The corporate principle of manufacturing chocolate products in domestic markets reduces the operational efficiency of the organization. In addition, the company is exposed to FDA regulations as it operates in the consumer foods industry. The strong global presence and high brand recognition are the major strengths of the company whereas expensive marketing campaigns seem to be a weakness of the business. Currently, M&M’s adopts a competitive pricing strategy because the product has been on the market for decades and there are numerous close substitutes for this product. Global market expansion, increased focus on social media promotion, and effective brand establishment are some of the marketing objectives identified for the M&M’s over the coming years. The organization is advised to rely mainly on direct and retail marketing channels to accomplish the marketing objectives proposed. The direct marketing channel strategy can benefit the organization to generate more sales through its website and to offer cheaper rates to end consumers. However, the business concern may also depend on other marketing channel strategies like advertising, sales promotion, and e-mail marketing that can increase its sales vol ume and meet marketing objectives.

Climate change and its effect on animals in the chesapeake bay Essay

Climate change and its effect on animals in the chesapeake bay - Essay Example Drastic weather patterns have led to rising of sea level causing submergence of wetlands in the estuary. This affects the wetland organisms that are not used to submerged ecosystems. The unpredictable weather patterns are likely to destabilize wetland habitat leading to extinction of some animal species. High variations in salinity as a result of increased rainfall, long periods of draught and unpredictable storm is also a factor that is likely to contribute to degradation of the ecosystem and extinction of animal species (Abel, 26). Increased precipitation as a result of climate change has led to high sediment deposits in the bay, which bring in high quantities of nitrogen and phosphorous that are the limiting nutrients for the growth of algae and other aquatic organisms. Further more, overland flow from neighboring farms and towns leads to deposition of chemical contaminants in the water that leads to the death of aquatic organisms. High sedimentation has raised the water bed leading increased submergence of the land surrounding the bay (Cerco et al. 632). Climate change has also led to temperature fluctuations and increased carbon dioxide in the atmosphere creating conditions that are necessary for the growth of dinoflagellates, which are algae that are harmful to zooplankton and fish. Some of the fish feed directly on the algae while others ingest the harmful algae through feeding on the zooplankton that are higher on the food chain. Moreover, temperature fluctuations increase the possibility of hypoxia. This is a situation whereby dissolved oxygen levels fall below the minimum that is necessary to support animal life. Increased temperatures in the bay have favored warm water species thereby making it hard for the cold water species to survive (Boesch et al. 112). Increased temperatures in the bay water have led to the decline of eelgrass which is a significant hideout of blue crabs in their post larval and molting

Great Expectations Essay Example for Free

Great Expectations Essay QS. Look carefully at the opening chapters of great expectations and explore some of the ways in which Dickens captures and keeps the interest and attention of the reader. Explore also how social conditions of the time inform his writing. When Dickens writes he uses three methods to interest his readers, the presentation of character, creation of atmosphere and his use of narrative, description and speech. To begin with we will look at dickens presentation of character. When my English class first began reading great expectations I noticed that Dickens did not describe a character physically or through their thoughts, instead he describes them with two details, their surroundings and their past. For example we are never told that Pip is blonde or his age etc, instead we are only told that he has a married older sister who cares for him and that they live quite simply for example we learn that for dinner they would have something like buttered bread which suggests that they have poor nutrition. We are also told about the fact that when Pip was younger his parents died along with five of his siblings, which suggests that he comes from a family that were and still are struggling and this suggests that they are living in the popular social conditions of the time which were harsh cold, poor hygiene, no hot water or heat, high infant mortality rate etc and this is also suggested at the bottom of page two when Pip says I was undersized for my age and not strong, the house they live in is also described as being in the marsh country this method of Dickens I found to be quite striking as I have not before read a book that does the same, however I think it is very effective because it allows the reader to paint their own picture of the characters and give them a greater insight into the characters and helps them to understand the characters actions, thoughts and words. This also allows the reader to become more involved in the novel and therefore the readers interest is already being drawn in. These social conditions, so far mentioned inform the novel a great deal as it is the story-line of this young boy from a poor background, and because he has been raised by hand that this child is so meek and innocent, and because of this innocence, and by chance, he is given the opportunity to become someone, quite literally, a man of great expectations In the first two chapters it is also noticeable that Dickens starts to give particular traits to each character to make them individual, such as Mrs Joe Gargery Was the evil step-mother while her husband Mr Joe Gargery was the quiet and almost wimpy yet kind man. Dickens narrative technique is also very powerful. Unlike most novels the action starts almost straight away. By page two we are shocked by the very sudden arrival of Magwitch with the shocking and almost frightening line Hold your noise! We are suddenly completely sucked in to the story when we find very quickly that Pip, the young boy we have become fond of is in danger and that Magwitch has only just escaped from a prison ship and is in desperate need of food, drink and possibly a file, if he will be able to make a full escape. This makes the first chapter become very exciting. Also it seems quite realistic because Magwitchs language is very powerful because it is so graphic, blunt and colloquial. Also Magwitch not only speaks in the way you would expect a convict to speak but he dresses how you would expect as well. Dickens uses many subordinate clauses and he also uses the word and a lot yet he uses it with style and it makes his writing seem much more rhythmic, for example in the third paragraph in the first chapter when Pip is telling us of his first memory, he says My first most vivid and broad impression of the identity of things and that the small bundle of shivers growing afraid of it all and beginning to cry, was Pip Dickens mainly keeps our attention by using drama such as when Magwitch enters on page two. Another way in which Dickens sustains the readers attention is his use of language in the way he writes. For example the type of words he uses to describe the new characters intrigues the readers so that they want to know more such as when Mr Joe Gargery is being introduced, In the middle of page six, Pip describes him as being a sort of Hercules in strength, and also in weakness. This seems to be very confusing and makes the reader want to continue in the story in order to figure out its meaning. Finally the most effective way which Dickens uses to with-hold the readers attention is through the creation of atmosphere. By using words such as raw, bleak, marsh and phrases like overgrown with nettles, dark flat wilderness etc. the writer makes the scene seem gloomy, drag and sad, and with the opening setting not only being in a churchyard, but a graveyard, we are subconsciously being prepared for Magwitchs arrival. Pip describes the river as a low leaden line This is a perfect example of Dickens art of alliteration. The word low is also representing the low spirit of Pip, The word Leaden makes us think of something that is heavy, grey and dull, and the word line sounds very bland and boring. Also the way in which Dickens uses personification for example in calling the wind a savage beast, these words make us think of Pip a small helpless child who is out alone in what seems like an extremely solitude and scary place. We then fear for this young child and want to learn what happens to him so once again the reader finds that they wish to continue in the book, and for the rest of the novel the drama and language that Charles Dickens uses makes us keep wanting to read on continues Therefore it is through using the techniques previously mentioned, of character presentation, creation of atmosphere and narrative, description and speech that Dickens gains and sustains his readers attention. Show preview only The above preview is unformatted text This student written piece of work is one of many that can be found in our GCSE Great Expectations section.

Research Paper Into Acne

Research Paper Into Acne Acne is a common skin condition, inflammatory skin or disease characterized by pimples on the face, chest, and back. It occurs when the pores of the skin become clogged with oil, dead skin cells, and bacteria. That will show the type of acne, how the different creams and meds that people use plus the side effects (That will make a difference to others). Lindsay and Kayee both used acne cleanser and moisturizers to cure their acne (Which worked on both of them). They both said that after many years or so, their skin cleared up. The difference was though was Lindsay also used jojoba oil that she mixed with the moisturized, which is on her drier days (Especially in the evenings).Kayee just cleanser and moisturizer. Even though she couldnt believe it and said Its not a fluke. It toke the amazing difference of it. Both girls also said they stop using makeup because it kills the skin and gives it a lot of acne and so on. I think that almost every girl stop using makeup ever since they found a way to clean their skin. Also, as you can tell too that a lot of woman dont seem to think right away when using acne cream (Im not saying that they are stupid) because whatever they seem to pick, it doesnt have Benzoyl Peroxide. BP is a type of a chemical incorporated into the polymer of resins to aid in the initiation of polymerization. Its also an antibacterial, keratolytic drying agent prescribed in the treatment of acne. It doesnt hurt your skin as much but more tickles but it also depends on the person because it might either irritate the skin or etc. I been through acne also and I still have. How I know this because I been to the doctors and I had from creams to pills and it dont work much (Even the pill who made me sick). So I went to proactive and its been helping slowly. Let just be thankful that some of us dont have skin diseases and so on because the skin disease is the more prevalent that affects nearly 17 million people in the United States. Its called acne vulgarism or just common acne. Still, that wouldnt be fun with that and trying to figure out from how you got it to etc. Anyways, did you know that nearly 85% of young people develop acne at sometime between ages 12-25 years? Which usually beings at puberty then worsen during the most occurring of ages 14-18. However, acne can come at any age from newborns to older adults. Its more common and severe in males than females. And also true that people continue to have acne outbreaks well into adulthood. Not that Im surprised about the acne continuing still, even trying to get rid of it, you still get more no matter. But also, males have more effected of this problem more than females. Yet, I see more females with acne problems more than males. Well, it does seem my guessing was wrong but also, its sometimes (not all) right about it. But also, people are different and get it when they get it. But how do we know how it develops? Well acne originates in the oil or sebaceous glands that lie beneath the surface of the skin. These glands that produce oil and are called sebum are the skins natural moisturizer. That helps preserve the flexibility of the hair. This shows the most common of acne places (except for the face) is really the chest, shoulders and back. That has the most sebaceous follicles which are opened into the skin that goes through pores, allowing sebum to reach the hair and skin surface. The worse type of acne only occurs when the follicles that are infected continue to enlarge (Without any rupturing, nodules, and cysts). Other acne or microorganisms can be involved also like acne vulgarism that can affect a womans face. Also no inflammatory like white and black heads. White and black heads are quite similar but mostly different because white heads have this plugged follicle that begins to bulge as a small whitish bump, which is underneath the skin mostly. For black heads, if the comedo opens up, the top surface of the plug darkens as its exposed to the air. Acne isnt a serious health threat. It just causes negatively that causes appearance from teens mostly because of social or etc. Its also permanent in scarring wise but still, we all go through it. Even though there are creams and meds that can cure some of this stuff or maybe all. They are like millions of creams, moisturizers, etc to make all your acne go away. You just need to find the right one and see how it goes. The ones I see a lot or mostly in commercials is proactive and Clearasil that been advertised. There are probably more than those two that are shown around. But still, they are like the only ones (Well except for the one the dermatologist gave me plus the pills) that I used so far that helped my skin. Proactive is definably better because it has helped me plus it gives you the mask plus lotion to relax your skin. Other people like this girl used Natures Cure along with Clearasil because she had an awful time with proactive but still, the other stuff helped her. Another girl said that proactive worked for her sister and it looked amazing. Another girl said proactive didnt work for her so she used Neutrogena cleanser and etc. So whatever you use really, it would work one way or another. And you may or may not have clear skin. What causes acne is oil, makeup, stress, hormones, age, gender, hygiene, diet, drugs, etc. From oil like grease, not watching your hands, your hair, or washing your face it can give your face a lot of oil. Its really between your hands and hair that can cause it because if you dont wash them and you put your hands on your face, you would get acne. Or be your hair that is in your face, without pulling it back or taken care of it can cause acne. But also, it doesnt always cause this. Its mostly stress and hormones really. Plus puberty because it can take a lot out of you or youre starting to grow up day by day. Still, its most hormones that take the most damage because your changing and as your grow older, (for female) your period stops slowly and it can cause stress along but also, it gets irritating because you got to work a lot or so or just life in general. Either way, we all go through this (Im really not sure for male because they are different from us). In conclusion, No matter how much acne you have or whenever you got to live it forever, we all need to see that whatever happens. And it doesnt matter what product we use, it doesnt always work for everyone. No matter if its stress or etc, its life. Source Citation: Acne. Mercedes McLaughlin., Patience Paradox., and Margaret Alic, PHD.. Ed. Jacqueline L. Longe. 3rd ed. Detroit: Gale, Online update, 2007. 5 vols, updated October 2009. Works Cited: McLaughlin, Mercedes, Patience Paradox, and Margaret Alic. The Gale Encyclopedia of Medicine. Gale, 2009. Acne. Web. Source Citation: ACNE. SICK! Diseases, Disorders, Injuries and Infections. Online Edition! Detroit: U*X*L, 2008. Works Cited: Diseases, Disorders, Injuries and Infections. Gale, 2008. Print. Source Citation: Acne. Patience Paradox. and David Edward Newton, Ed.D. The Gale Encyclopedia of Alternative Medicine. Ed. Laurie Fundukian. 3rd ed. Detroit: Gale, 2009. 4 vols. Works Cited: Paradox, Patience, and David E. Newton. The Gale Encyclopedia of Alternative Medicine. Gale, 2009. Print. Regimen success stories 1997 2010 Daniel W. Kern http://www.acne.org/success.php Benzoyl peroxide http://www.answers.com/topic/benzoyl-peroxide I need your PROACTIV STORIES whether good or bad!? http://answers.yahoo.com/question/index?qid=20070316190446AA5sE54

Incentives in Human Subject Research

Incentives in Human Subject Research Reka Zsilinszka The use of incentives permeates throughout all aspects of medicine; from bonuses for holiday or overnight shifts, to loan forgiveness programs for physicians practicing in underserved areas, incentives serve an important role in promoting patient care. In the vast majority of situations, the use of incentives in medicine is an unproblematic and elegant solution to issues with staffing or access to care. However, when employed in human subjects research (HSR), the use of incentives is often uncharted territory[REM1]. There are limited formal guidelines that delineate the correct application of incentives and compensation in research, and the issue remains largely unresolved. Thus, the ethics [REM2]of compensation often boils down to the specific type of patient population under study. In this paper, I will discuss the differences between vulnerable and non-vulnerable patient populations, and expound on the use of incentives in each of these populations in the context of modern medical ethical codes. Definitions As stated previously, the use of incentives in most aspects of medicine is rarely considered unethical. It is only when incentives – monetary or otherwise – are used as undue [REM3]influence in order to promote participation in a study that the use of incentives can cross an ethical boundary. Oxford English Dictionary defines undue influence as â€Å"influence by which a person is induced to act otherwise than by their own free will or without adequate attention to the consequences.†[1] Therefore, one of the most important concepts in a discussion about the ethics of incentives in human subjects research is that of a vulnerable subject, because it is this population of patients that is most sensitive to the â€Å"undue influence† of incentives. We learned in Dr. Looney’s lecture â€Å"Research with Vulnerable Subjects† that there are several categories that define this population. In general, a vulnerable subject would be anyone that has limi tations on either their mental capacity or their voluntariness to participate in research; it is this latter definition that is most sensitive to undue influence. Thus, some examples of vulnerable subjects include people in emergency situations, children/infants/embryo, the mentally ill, people of a low socioeconomic or educational status, people with terminal illness, and people in hierarchical organizations where there are power differentials. While this list is by no means exhaustive, it gives an important sampling of patients that are often recruited by researchers, and who might be especially susceptible to undue influence by means of compensation in order to participate in a study[REM4]. Ethical Codes In order to properly discuss the ethics of incentives in HSR, it is imperative to also determine a set of ethical codes by which the issue of incentives can be judged. One of the most well known frameworks for medical ethics was the Belmont Report, drafted in 1979.[2] While there exist many other criteria for ethical research, such as the 7 Requirements posed by Emanuel et al[3], the Belmont Report is still considered to be one of the most widely known and widely cited works of ethical research involving human subjects. In the Report, there are three key ethical principles pertaining to human research: those of beneficence, respect for persons, and justice. Briefly, beneficence is the ethical duty to provide some sort of benefit to research subjects; in other words, this concept implies that the research in question minimizes risks and maximizes potential benefits to participants. Next, respect for persons is closely related to the principle of autonomy, and implies the right of the subject to be left alone[REM5]. Thus, the principle of ‘respect for persons’ is crucial when considering the voluntariness of an individual to consent to or refrain from participating in a study. Lastly, the principle of justice refers to the right of the individual and populations to be selected fairly for research, allowing all populations equal access to the benefits of research as well as ensuring that vulnerable populations are not being unfairly targeted. In presenting arguments about the ethics of human subjects research, we will therefore use the 3 main ethical principles of the Belmont Report to examine incentives for both vulnerable and non-vulnerable populations. Incentives in Non-Vulnerable Populations With respect to incentives in a hypothetical non-vulnerable population, we will examine whether there are any conflicts with the aforementioned ethical codes. Of course, the definition of a non-vulnerable population is a subjective one, as most human interactions have some level of a power differential between the participants; thus there are very few situations in research where a subject is completely non-vulnerable and not subject to some form of a power dichotomy[REM6] When considering the principle of beneficience, there is little violation of this code with regards to incentives in human subjects research, if the research has been deemed to have a reasonable risk: benefit ratio. With a non-vulnerable and competent consenting subject participating in research that has been IRB-approved and appropriate, there is no real ethical quandary between incentives and beneficience[REM7]. Next, we consider respect for persons, or autonomy. In a population where power-differentials have been minimized, the patients should have no effect on their free will to choose whether or not to participate in a study[REM8]. Thus, a fair and appropriate incentive would not make them go against their own best judgment to participate in the study, since this latter point would be considered a form of coercion or undue influence. For example, I propose this hypothetical situation: if there were a study that required a number of blood draws and the incentives in this case were monetary, then targeting a population that is financially stable would likely not significantly affect their autonomy; they should be able to weigh the risk and benefits and decide to participate based purely on their own best judgment. However, this situation might be very different when primarily targeting a low income population, where the subjects might have major qualms about needles or getting their blood d rawn, but would feel forced[REM9] to agree to participate due to their need for financial resources. Finally, we consider the juxtaposition of the ethical principle of justice and incentives in non-vulnerable populations. Once again, as with the beneficience, there are really no ethical quandaries in this situation, as there should be fair and equal subject selection with no large variations in access too research. It is only when dealing with vulnerable or â€Å"difficult to reach† populations (i.e., underserved minorities, prisoners, children, people of low socioeconomic status) that there might be issues with the concepts of justice and compensation. Thus, it is clear that when considering non-vulnerable populations, there are no real issues with using incentives to promote participation in approved human subjects research[REM10]. The real ethical quandaries arise when there are major differences in power, status, or ability to make autonomous decisions. Incentives in Vulnerable Populations We will now revisit our familiar ethical codes and discuss them in a different light, focusing on vulnerable populations and using specific historical examples when applicable. In the case of beneficience, it is mostly the job of the research team and governing boards to minimize risk and maximize benefit; thus the use of incentives does not really enter into play here. The only situation in which incentives might alter the researcher’s concept of beneficience, is if, for example, there was a study with a high risk and variable benefit, but the compensation was also comparably large; in this situation, the research team could therefore argue that it is up to the participants to decide the level of risk they are willing to take in exchange for a gain[REM11]. Respect for persons goes hand in hand with autonomy and voluntariness, and it is possibly the most difficult ethical principle to reconcile with incentives in vulnerable populations. In class, there are a few scenarios where incentives to vulnerable populations have resulted in abuse of certain research participants. For example, there was the instance of the US Public Health Service Guatemala STD study, where prisoners (a vulnerable population) were incentivized with prostitutes to participate in a study assessing syphilis and gonorrhea transmission; while this study also had major problems with the informed consent process, it also brings to light the issue that in certain populations such as prisoners, almost all incentives (sexual favors, better rooms, etc) can be considered undue influence because of the significant power between[REM12] the incarcerated participants and researchers. There is another famous example of the Willowbrook School, where parents were encouraged to enrol l their mentally retarded children into a hepatitis research project in exchange for admission into a highly competitive residential facility for the children. In this case, the vulnerable populations were both the children who were often too young and mentally incompetent to make autonomous decisions, and the desperate parents who were subject to the undue influence of admission to the facility to make a decision that might have gone against their better judgment. On the other hand, it is important to remember that, for some research participants, the various incentives gained from research are an invaluable source of income and other benefits. A fellow third year medical student is currently conducting HIV- research in the Dominican Republic, and her population of interest is sex workers; for these workers, the only way to incentivize them to participate in this research is to reimburse them for their time, and it is also an opportunity to provide valuable antiretroviral medication and education[REM13]. Additionally, there is a lot of important medical and epidemiological knowledge to be gained from HSR, which often justifies the use of incentives to boost enrollment in studies, even in vulnerable populations. Thus, in these various situations, it is crucial for the researcher to respect and understand the values and beliefs of the populations they are enrolling and studying. The research team must be sensitive and aware that some incentives may be simply too good to refuse for certain vulnerable populations, and that these people might be acting against their better judgment to participate in research. This sensitivity may require the team to abstain from offering lucrative and tempting offers to vulnerable participants in high-risk and low-reward research settings, even though the enrollment potential of the study may be therefore limited[REM14]. The last principle left to discuss in the context of vulnerable populations is that of justice, especially in the context of fairness in the subject selection. In this case, the populations that are most likely to be affected are either the poor sector, or ethnic minorities. This is due to the fact that people of a low socioeconomic status are sometimes more likely to be targeted and exploited for research participations, due to a potentially lower cost of incentives for certain studies. The converse can also be true when testing out advanced medical innovations where people who are of a lower socioeconomic status or have less access to medical care might not initially be recruited to the benefits of such a study. Another interesting issue that has arisen due to the US history of mistreatment of certain minorities (most notably African-Americans in the Tuskegee syphilis experiments) is that there is a certain level of mistrust among minority populations towards human subjects researc h.[4] However, in order to adhere to the principle of justice, there must be fairness in subject selections as well as equal access to the benefits of research. Due to misdeeds of the past, these seeds of mistrust can prevent certain groups from participating in research, and one of the easier solutions is to offer greater compensation in order to elicit participation. This practice is not fair, since some subjects are receiving greater compensation in order to convince them to participate in studies, and this can blur the ethical lines of both respect for persons as well as justice. This is a yet unresolved issue; on the one hand, we need subjects of different races and ethnicities to participate, but it is not fair to compensate certain subjects differently as compared to others. The greater issue here is to heal the rift and historical mistrust that has developed over years of mistreatment of certain populations, and to treat all participants with maximal respect when enrolling f or studies[REM15]. In conclusion, there are no easy answers when it comes to determining the ethics of incentives. The most important point to consider is that each individual has different sets of values, beliefs, and backgrounds, and it is up to the research team to be diligent about informed consent, autonomy, and education. If researchers are sensitive to the financial, socioeconomic, and various hierarchical power differentials that they may encounter in the process of enrolling patients in studies, then there can be a more open and honest discussion with the participants about the risks and benefits of participating in research, even when there are incentives offered. In this way, we can make sure that our patients are not being coerced into participating in HSR, but are able to contribute to society in a meaningful way that does not conflict with their inner ideals[REM16]. [1] Concise Oxford English Dictionary.Concise Oxford English Dictionary. Ed. Angus Stevenson and Maurice Vaite. N.p.: Oxford UP, 2011. 1575.Google Books. Web. 16 Apr. 2015. [2] The National Commission for the Protection of Human Subjects of Biomedical and Behavioral Research.The Belmont Report: Ethical Principles and Guidelines for the Protection of Human Subjects of Research. Rep. N.p.: n.p., 1979.US Department of Health and Human Services. Web. 17 Apr. 2015 [3] Emanuel, E. J., D. Wendler, and C. Grady. What Makes Clinical Research Ethical?JAMA283.20 (2000): 2701-711.JAMA Network. Web. 17 Apr. 2015. [4] Grant, R. W., and J. Sugarman. Ethics in Human Subjects Research: Do Incentives Matter?Journal of Medicine and Philosophy26.9 (2004): 717-38. Web. [REM1]I’m not sure it’s uncharted. There’s been lots of discussion, but there isn’t a clear consensus. So perhaps â€Å"uncertain territory† fits better. [REM2]It’s fussy, but it’s not the ethics (those are more constant), but rather the issues related to compensation that often boil down to the patient population. [REM3]Critical – what makes it â€Å"undue† – let’s see†¦ [REM4]I hope you pick up that in many cases the influencing factors in cases of vulnerable subjects are meant to induce the signatory agent, who may not be the research subject. Separate influencing the subject and influencing the decision maker. [REM5]Much more than that – it’s the right of the individual to control their own life, to make the decisions that matter to how their life will proceed. [REM6]Maybe â€Å"hierarchy† would be better. â€Å"Dichotomy† implies a binary split – it’s correct, but less flexible. [REM7]This notion seems abstractly reasonable, but might there be some dispute as what represents the best interest of the patient/subject? Does trying to sway someone from one beneficial study to another constitute influencing, perhaps undue? [REM8]I think you could state this more clearly. [REM9]Forced? Or desirous of participating in order to achieve the financial gains? [REM10]Hmm – how would you feel if I offered you $15,000 to participate in research? I don’t consider you vulnerable, but would this make you willing to accept risks that you otherwise might not? [REM11]A classic is bribing parents to â€Å"buy† child research subjects. Diapers work well†¦. The worry is that even with beneficent research, there may be choices, and the vulnerable subject may not be able to navigate the choices well. Beneficence in-and-of-itself is not sufficient to decrease the worry related to undue influence. [REM12]Power differential between [REM13]That’s a great case! You can see the potential of the incentives for good but for those who think the decision to participate in research should be independent of anything other than the intrinsic value of the research, it’s undue inducement (a point with which I do not agree) [REM14]You’ve made a decision that’s different than the purists I described in the last comment would favor. [REM15]Demonstrating that truly achieving justice can be a complicated matter. [REM16]Conceptually, you were on the right track, but your discussion isn’t very nuanced.

Things Fall Apart Essay -- essays research papers

Things Fall Apart: An Evaluation In â€Å"Things Fall Apart,† Chinua Achebe tells two different stories at the same time. One is of Okonkwo, the villager whose rise to power is halted because of all of his misfortunes. The other is of Okonkwo’s village, Umuofia, and its struggle to hold on to its cultural tradition while facing colonialism from the West. The title, â€Å"Things Fall Apart,† describes perfectly what happens to both Okonkwo and his village. Okonkwo’s life falls apart and as a result, he commits suicide by hanging himself. The cultural tradition of Umuofia falls apart, and becomes influenced by the West. In â€Å"Things Fall Apart,† Achebe uses Okonkwo and the village’s falling out to show how African culture, as well as other cultures around the world, suffered as a result of Westernization. In the book, Achebe focuses mainly on the character of Okonkwo. Okonkwo’s story follows the general pattern of a Greek tragedy. He experiences many successes in the beginning, but everything eventually comes crashing down on him. His early life is the typical success story. He starts poor, but works hard to earn everyone’s respect. From the beginning he is disgusted with his father. He is a lazy old man who borrows money and never pays it back. Okonkwo realizes that he does not want to be like his father, and it is this hatred that drives him to work hard. After his father’s death, Okonkwo pays off his debts, and starts his long journey to the top of the clan. In a short time, Okonkwo...

Nontraditional Traditions :: essays research papers

Nontraditional Tradtions We live in an age in which it is hard to spend time together as a family. Many families today wonder if having quality time together is a thing of the past. We are inordinately busy, for one thing, whether household bread-winners or college students. Also, the definition of family has changed. We are dealing with new definitions and characterizations of the idea of family. Some of us have traditional families. Some families have divorced, single, and/or remarried parents, creating a rather confusing family tree. Some people choose to live their lives alone, but may still be close enough to some friends to consider them family. Whatever the circumstances, many of us honestly don't know how to celebrate together. We may even see the word "tradition" as something stultifying and old, having no meaning for or application to us personally; something usually being forced upon us by someone who smells funny and is only seen on holidays. What all of this means is that we can no longer simply follow the examples of old. It is up to us to create new family traditions. Celebrating is not hard. We all know about celebrating and have some ways of doing it. The only challenge is to find new ways. Why do we need to celebrate tradition? It gives us something to look forward to and makes a formal statement that there are some things in life to be grateful for. The notion of honoring tradition is unsettling for some people; let alone creating new ones. We understand that we need something to add a sense of order and stability to our lives. But we are not sure about how to create our own traditions. We seem to think that traditions must be heavy and complex ideas that had been around for hundreds of years and will be around for a hundred more. In my opinion, this is not true. It need not be big or religious at all. I believe a tradition is something that you do once that feels good, so you do it again and again. The tale in Frost's "Mending Wall" can be viewed as an impromptu tradition. The two neighbors needing to repair the wall after the winter chill, find time to converse with each other about what's on their minds. For example, every Sunday my dad makes tea and puts out two cups, his and mine. I am used to this. If I had to reach in the cupboard to get my own cup, something would be wrong. As it is, I get up out of my bed, I go into

Cellular Manufacturing System

What is Lean? Running an operation lean means: Removal of waste of all kinds (e. g. time, motion, inventory, poor cost of quality, etc. ) An organization that stimulates productivity and quality An organization using value-added processes Low Quality = High Waste High Quality = Low Waste and Higher Value There are several ways to be Lean— TQM Six Sigma SMED (Single Minute Exchange of Die) PM/TPM (Preventive Maintenance/Total Preventive Maintenance) JIT (Just In Time) Continuous Improvement/Kaizen And Many More†¦CELLULAR MANUFACTURING: MANUFACTURING A Lean Manufacturing Concept Cellular Manufacturing One of these lean practices, cellular manufacturing, is based on a group of different processes located in close proximity to manufacture a group of similar products. The primary purpose of cellular manufacturing is to reduce cycle time and inventories to meet market response times. Some of the other benefits include: Space Reduction Quality Improvement Labor Cost Reduction Im proved Machine Utilization Where would you begin? First, you would define the cell you plan to create.Criteria required for defining the cell would be based on: Processes Required Part Numbers & Attributes (size, shape, raw materials required) Market segments/customers Degree of Automation By Jay P. Patel, Principle Consultant, Quality & Productivity Solutions, Inc. Copyright ©2000 by Jay Patel Cellular manufacturing is an application of the group technology concepts for factory reconfiguration and shop floor layout design. A part family can be parts similar in size or parts created using similar manufacturing steps.Typically, a cell is dedicated to a single part family. Cellular manufacturing does have some important human resource issues to consider: Operators must be trained properly to perform tasks including inspection and simple maintenance Cross functional training is critical since operators perform a variety of tasks and move between workstations and cells as the need ari ses Operators should be trained on Team Building Supervisors become Coaches. Cell teams require only guidance. Supervisors facilitate, assist nd guide the overall effort. Compensation issues: Cell employees usually receive the higher pay because they are better qualified to do multiple tasks. We recommend implementation of an incentive program that provides incentives on the basis of results and incremental improvements. Management may be concerned that there will be resistance from employees when the result is actually opposite. Typically, any initial resistance disappears once employees understand the win-win situation at hand.Cells need support from several functions including product engineering, material management, manufacturing engineering, QC/QA, maintenance and management. It is vital to implementation success that this support is committed, visible and consistent. Team Selection Most crucial to the implementation of cellular manufacturing is team selection. To help determi ne who is best to include in your team, identify the skills required for each step by creating a Process Map. Clarify the roles and responsibilities of the roles you need filled.Once the skills are identified, determine the potential team members. Explain to potential members what the nature of the task is and get a feel for their interest. What will you look for in your team members? Understanding the importance of selecting the right team cannot be overemphasized. Both objective and technical criteria should be established, including skills in: teamwork interpersonal skills leadership skills change adaptation positive thinking Develop a checklist for selecting these members based on the needs of the cell.This can also be used in setting goals for those who wish to grow in their own skill sets. 2 From here you will need to do some negotiating. You will need to meet with affected Supervisors to discuss: Overall priority Current structure and plans Current authorities and relative po wer of team leaders Potential team members and the support they will need Negotiate to acquire members best suited for the team. Renegotiate as necessary with the help of management and a detailed implementation plan. Skill Matrices Match skills to tasks.Create a matrix to define who is best qualified to perform specific tasks. This will be the document used for contracting your team to the project: aiding in obtaining commitment as well as communicating responsibilities and expectations. Determine what training is needed and implement a training plan. Make sure communication lines are established, open and well used. The success of the program is contingent on the team dynamic and the goals set. Communication is key—learn to listen and help others to do the same. What are the communication channels and links? Who provides and who expects what?Can the team members accomplish the tasks assigned? Team Management Develop trust and provide the team a reason to be motivated. Learn to manage team morale and create a system to encourage teamwork. Make your team an example of how successful teams cause great things to happen. Start with a pilot cell—be sure the product family chosen has the most potential for success. Stockpile if possible to provide an alternate source during implementation. When changes are necessary, communicate the reason for these changes in order to gain acceptance and understanding from your team.Be confident in implementation. Designing the Cell Cell design should be based on your project needs. Keep in mind the following when designing the cell: product life cycle continuous, flowing work through the cell proper allocation of resources for gauging and tooling aggressive update of equipment and processes cell development is evolutionary and always in a state of flux challenges in facility changes due to structure and age Involve your team and their knowledge in the construction of the cell.Understanding throughput is essential to cell development—do not underestimate the contribution and acceptance of the team once the concept is understood. Ultimately, the logistics and cell construction is only a small part of the battle. Creating a culture where a team can flourish is the hard part. This task requires a true leader. Can you meet the challenge? -JPP 3

Can Machines Think?

Can Machines Think ? This paper regards several points of view on the subject of, what is commonly referred to as Artificial Intelligence, or AI. AI is the attempt to make machines, specifically computers, perform intelligently through programming. Already, this definition has a problem in that the word intelligence can have many interpretations. This essay will attempt to put forward some ideas for how to approach this problem.It could be said that the human brain is nothing more than a machine, and as we know it to be capable of thought it would be fair to surmise that therefore machines can think and it is probably this, or a similar premise that inspired AI. However, within AI there are many schools of thought. Some believe that if a computer can be programmed correctly to emulate certain human processes, then it is to all intense and purposes thinking as we do.One of the early pioneers in the world of computers, Alan Turing, outlined a test in which participants are asked to int errogate a computer terminal in order to determine whether they are communicating with a human, or a computer program. Examples of programs which were put through the Turing test are ELIZA and SHRDLU both of which attempted to emulate one side of human conversation. But even if these programs did appear to be totally human, could they be said to actually be thinking ? John Searle(1984) puts forward a scenario in an attempt to devalue this idea.He refers to a program by Roger Schank at Yale university which, after being given a story will be able to answer questions regarding it. It would seem at the outset that this program would therefore be understanding the story. Searle then argues that despite not being able to understand Chinese, he would, under the correct circumstances, be able to answers Chinese questions in Chinese, relating to a story also written in Chinese. The scenario is summarised as follows; Sitting isolated in a room, Searle is given a wad of Chinese script, follow ed by another. In addition he is given a list of English rules, for correctly correlating the two.By simply following the English rules, he writes a third set of chinese words which he then returns to someone outside the room. If the first set of script was a story, the second a set of questions, he could be said to be answering the questions. In fact, from the point of view of someone standing outside the room, he would be correctly answering the questions, and thus would appear to be conversant in Chinese. This of course is not the case, as Searle would have no knowledge of what the story was about, and what the questions were asking – he would not be understanding the story.This argument is an attempt to demonstrate that although a computer program appears to be understanding a story, it is merely obeying simple instructions, and has no understanding at all. â€Å"In the linguistic jargon, they have only a syntax but no semantics† (Searle 1984) However, depending on hown one observes this problem, it can appear very differently. Regarding the entire room, the person in the room (to whom I shall refer for the sake of continuity of terms as a demon), the scripts and the person outside as a whole, we do have a system that is capable of reading and interpreting Chinese.Hofstadter extends this idea by modifying the scenario so as to shrink it to brain size, the scripts becoming neurons and so on. This effectively creates a system equivalent to the human brain. So what would be the difference between the two. Why would one be acceptable as a thinking system and one not ? Searle frequently refers to ‘causal properties' and ‘intentionality' stating that the artificial system proposed by Hofstadter would lack both of them, and that somehow the human brian has both.It is here where the subject of duality comes into the fore. Are the mind and the brain one and the same, or are they separate entities ? Many religions favour this dualist approa ch and refer to the mind, as it is in this instance, as a persons soul and regard it as being separate to the physical self. Whether the mind is separate or not, Searle's argument implies that the human brain has a mind, because of its natural causal properties, yet an artificial machine does not. But what are these natural causal properties, and from what do they derive ?Are they a result of the biological material from which the brain is made, are they a result of the brain's structure or are they a result of a breath of life from the lips of a god ? â€Å"Machines as simple as thermostats can be said to have beliefs, and having beliefs seems to be a characteristic of most machines capable of problem solving performance† (McCarthy 1979) At what point does a functioning machine gain intentionality ? Here Zenon Pylyshyn is cited from a reply made to Searle, to illustrate the complex connotations involved in the idea of the natural causal property of the brain. If more and mor e of the cells in your brain were to be replaced by integrated circuit chips, programmed in such a way as to keep the input-output function of each unit identical to that of the unit being replaced, you would in all likelihood just keep right on speaking exactly as you are doing now except that you would eventually stop meaning anything by it. What we outside observers might take to be words would become for you just certain noises that circuits caused you to make. Surely, the person in the above example would have conscious, intentional thought, despite being constructed from artificial parts. Or would this person simply be acting in the same role as the chinese room demon ? Another area rapidly developing in AI is Parallel Distributed Processing, or neural networks. These are complex structures that emulate the brains neural structure, and are usually modelled within a computer, although in theory there is nothing to stop them being constructed electronically, or even mechanically !The effect of a neural network is similar to that in Pylyshyn's example – an electronic replacement for a part of the brain. Functionally it operates almost identically to a brain and can be made to do tasks similar to those performed by Schank's story program. Could a neural network equivalent be said to have any more ‘causal properties' than just a computer program ? Searle acknowledges that since we are merely machines, it is possible that machines can think.However he finds the idea of a computer program thinking implausible. However, if we could model a brain, with atomic accuracy in a computers memory, for example in the form of a neural network, surely it would work in exactly the same way and would therefore be just as valid a thinker as a human. It seems that this whole debate rests its most basic principles on a belief; either one believes that our ‘intentionality' derives purely from our brain and its structure or one doesn't.Even if we ever do manage to construct an exact replica of a brain that appears to work identically to the real thing, how could we tell if it really is a conscious entity with true intentionality, or merely acting like the chinese room demon ? Indeed, how can we define conscious, and intentionality in that context. There must be a level of functioning or reasoning that we can use as a cut-off point for deciding whether or not something is alive and thinking. Descartes stated â€Å"I think. Therefore, I am†. But was he thinking, or merely following a mechanical pattern, with no real understanding of the words ? References Can Machines Think? Can Machines Think ? This paper regards several points of view on the subject of, what is commonly referred to as Artificial Intelligence, or AI. AI is the attempt to make machines, specifically computers, perform intelligently through programming. Already, this definition has a problem in that the word intelligence can have many interpretations. This essay will attempt to put forward some ideas for how to approach this problem.It could be said that the human brain is nothing more than a machine, and as we know it to be capable of thought it would be fair to surmise that therefore machines can think and it is probably this, or a similar premise that inspired AI. However, within AI there are many schools of thought. Some believe that if a computer can be programmed correctly to emulate certain human processes, then it is to all intense and purposes thinking as we do.One of the early pioneers in the world of computers, Alan Turing, outlined a test in which participants are asked to int errogate a computer terminal in order to determine whether they are communicating with a human, or a computer program. Examples of programs which were put through the Turing test are ELIZA and SHRDLU both of which attempted to emulate one side of human conversation. But even if these programs did appear to be totally human, could they be said to actually be thinking ? John Searle(1984) puts forward a scenario in an attempt to devalue this idea.He refers to a program by Roger Schank at Yale university which, after being given a story will be able to answer questions regarding it. It would seem at the outset that this program would therefore be understanding the story. Searle then argues that despite not being able to understand Chinese, he would, under the correct circumstances, be able to answers Chinese questions in Chinese, relating to a story also written in Chinese. The scenario is summarised as follows; Sitting isolated in a room, Searle is given a wad of Chinese script, follow ed by another. In addition he is given a list of English rules, for correctly correlating the two.By simply following the English rules, he writes a third set of chinese words which he then returns to someone outside the room. If the first set of script was a story, the second a set of questions, he could be said to be answering the questions. In fact, from the point of view of someone standing outside the room, he would be correctly answering the questions, and thus would appear to be conversant in Chinese. This of course is not the case, as Searle would have no knowledge of what the story was about, and what the questions were asking – he would not be understanding the story.This argument is an attempt to demonstrate that although a computer program appears to be understanding a story, it is merely obeying simple instructions, and has no understanding at all. â€Å"In the linguistic jargon, they have only a syntax but no semantics† (Searle 1984) However, depending on hown one observes this problem, it can appear very differently. Regarding the entire room, the person in the room (to whom I shall refer for the sake of continuity of terms as a demon), the scripts and the person outside as a whole, we do have a system that is capable of reading and interpreting Chinese.Hofstadter extends this idea by modifying the scenario so as to shrink it to brain size, the scripts becoming neurons and so on. This effectively creates a system equivalent to the human brain. So what would be the difference between the two. Why would one be acceptable as a thinking system and one not ? Searle frequently refers to ‘causal properties' and ‘intentionality' stating that the artificial system proposed by Hofstadter would lack both of them, and that somehow the human brian has both.It is here where the subject of duality comes into the fore. Are the mind and the brain one and the same, or are they separate entities ? Many religions favour this dualist approa ch and refer to the mind, as it is in this instance, as a persons soul and regard it as being separate to the physical self. Whether the mind is separate or not, Searle's argument implies that the human brain has a mind, because of its natural causal properties, yet an artificial machine does not. But what are these natural causal properties, and from what do they derive ?Are they a result of the biological material from which the brain is made, are they a result of the brain's structure or are they a result of a breath of life from the lips of a god ? â€Å"Machines as simple as thermostats can be said to have beliefs, and having beliefs seems to be a characteristic of most machines capable of problem solving performance† (McCarthy 1979) At what point does a functioning machine gain intentionality ? Here Zenon Pylyshyn is cited from a reply made to Searle, to illustrate the complex connotations involved in the idea of the natural causal property of the brain. If more and mor e of the cells in your brain were to be replaced by integrated circuit chips, programmed in such a way as to keep the input-output function of each unit identical to that of the unit being replaced, you would in all likelihood just keep right on speaking exactly as you are doing now except that you would eventually stop meaning anything by it. What we outside observers might take to be words would become for you just certain noises that circuits caused you to make. Surely, the person in the above example would have conscious, intentional thought, despite being constructed from artificial parts. Or would this person simply be acting in the same role as the chinese room demon ? Another area rapidly developing in AI is Parallel Distributed Processing, or neural networks. These are complex structures that emulate the brains neural structure, and are usually modelled within a computer, although in theory there is nothing to stop them being constructed electronically, or even mechanically !The effect of a neural network is similar to that in Pylyshyn's example – an electronic replacement for a part of the brain. Functionally it operates almost identically to a brain and can be made to do tasks similar to those performed by Schank's story program. Could a neural network equivalent be said to have any more ‘causal properties' than just a computer program ? Searle acknowledges that since we are merely machines, it is possible that machines can think.However he finds the idea of a computer program thinking implausible. However, if we could model a brain, with atomic accuracy in a computers memory, for example in the form of a neural network, surely it would work in exactly the same way and would therefore be just as valid a thinker as a human. It seems that this whole debate rests its most basic principles on a belief; either one believes that our ‘intentionality' derives purely from our brain and its structure or one doesn't.Even if we ever do manage to construct an exact replica of a brain that appears to work identically to the real thing, how could we tell if it really is a conscious entity with true intentionality, or merely acting like the chinese room demon ? Indeed, how can we define conscious, and intentionality in that context. There must be a level of functioning or reasoning that we can use as a cut-off point for deciding whether or not something is alive and thinking. Descartes stated â€Å"I think. Therefore, I am†. But was he thinking, or merely following a mechanical pattern, with no real understanding of the words ? References

Evaluation of Waste Tire Devulcanization Technologies

(INTERNAL REPORT) CENTERPLASTICS COMPOUND & ADDITIVES Feb. 2011 – M. S. Laura Fontana – Centerplastics Enterprise, Ltd Eastern Industrial Road, zip. 516127, Shiwan Town, Boluo Area, Huizhou, DongGuan, GuangDong, P. R. China PPH Chapter 1 – Introduction Approximately 25 potential devulcanization technology researchers and developers were identified throughout the world, however, only a very small number of devulcanization systems are now operating. These are primarily small-capacity systems, which are devulcanizing natural or synthetic rubbers (as opposed to devulcanizing the mixture of rubbers recovered from waste tires). The general types of devulcanization technologies identified and analyzed in the study are shown below. Technology Basis of Processing Zone of Reaction Chemical Chemicals/chemical reactions Surface of particles Ultrasonic Ultrasonic waves Throughout particles Microwave Microwaves Throughout particles Biological Microorganisms Surface of particles Other Mechanical Steam Surface of particles Key findings Reliable information and data on devulcanization of waste tire rubber are difficult to obtain due to proprietary claims, efforts to hide poor or infeasible process performance and product quality, and the limited number of technology researchers and developers and of peer-reviewed data. Reliable data relating waste tire characteristics, devulcanized rubber quality, end product performance, and production costs is scarce.  · Only a very small number of low-capacity devulcanization systems are operating in the United States (at approximately 50 Kg /hr, all R&D scale, mechanical, or ultrasonic). No proven commercial capacity units could be found that are currently devulcanizing waste tires, for example, at 500 Kg/hr or greater. The likely reasons include insufficient product quality and high costs of production.  · In terms of the potential of producing high-quality devulcanized rubbers (for example, high strength), the best technology appears to be ultrasonic, based on the current state of the art.  · Devulcanization of single rubbers has much more history than that of multi-rubber mixtures such as waste tires. Only a few companies devulcanize single formulation rubber as a result of captive conversion or merchant scrap recovery from manufacturing. The production of devulcanized rubber from home manufacturing scrap in the U. S represents about 1 to 2 percent of total U. S. rubber consumption.  · The quality of devulcanized single rubbers is higher than that of devulcanized multiple rubbers.  · Devulcanization that depends on surface devulcanization technologies (for example, chemical and mechanical) appears destined in the near term to produce low- or medium-quality devulcanized rubber material. The estimated cost for producing devulcanized materials from waste tires is $0. 3 to $0. 6/Kg  ± 30 percent, if including the cost of crumb rubber feedstock. This range of production costs is significantly greater than that of virgin rubbers. A typical tire compound contains the following constituents: Table 1. Composition of Tires Passenger Tire Constituents Common Materials Natural rubber 14 % Natural rubber Synthetic rubber 27% SBR, butadiene rubber Carbon black 28% Carbon black Steel 14%–15% Steel Fabric, fillers, accelerators, antiozonants, etc. 16%–17% Polyester, nylon, aromatic oil, coumarine resin, silica, bonding agent, stearic acid, ntioxidant, processing chemicals, sulfur, zinc oxide Truck Tire Natural rubber 27% Natural rubber Synthetic rubber 14% Synthetic rubber Carbon black 28% Carbon black Steel 14%–15% Steel Fabric, fillers, accelerators, antiozonants, etc. 16%–17% Polyester, nylon, aromatic oil, stearic acid, antioxidant, wax, processing chemicals, sulfur, zinc oxide Source: Rubber Manufacturers Association, 2004. †¢ Reclaiming is a procedure in which scrap tire rubber or vulcanized rubber waste is converted—using mechanical and thermal energy and chemicals—into a state in which it can be mixed, processed, and vulcanized again. The principle of the process is devulcanization (Franta, 1989). Historically and practically, in the concept of rubber reclaiming, devulcanization consists of the cleavage of intermolecular bonds of the chemical network, such as carbon-sulfur (C-S) and/or sulfur-sulfur (S-S) bonds, with further shortening of the chains also occurring (Rader, 1995). This description of devulcanization is different than that given below, which is limited to chemical interactions involving sulfur atoms. †¢ Reclaim is an interesting raw material as it reduces the production costs of new rubber articles, due to shorter mixing times and lower power consumption. The processing temperature is lower, and the material has a higher dimensional stability during calandering and extrusion due to the remaining three-dimensional network. The most important advantage of cured articles containing reclaim in terms of properties is an improvement of aging resistance. †¢ Devulcanization is the process of cleaving the monosulfidic, disulfidic, and polysulfidic crosslinks (carbon-sulfur or sulfur-sulfur bonds) of vulcanized rubber. Ideally, devulcanized rubber can be revulcanized with or without the use of other compounds. The different types of devulcanization processes also modify other properties of the rubbers. These processes cause diminution of some properties over those of the parent rubber. Ideally, devulcanization would yield a product that could serve as a substitute for virgin rubber, both in terms of properties and in terms of cost of manufacture. Polymers can be divided into two groups: thermoplastics and thermosetting materials. Thermoplastics soften when heated, making it possible to (re-)shape them at higher temperatures. Thermosetting materials, like rubbers, are crosslinked on heating and therefore cannot be softened or remodeled by raising the temperature. Therefore, thermosets are more difficult to recycle compared to thermoplastics. The three-dimensional network has to be broken in order to make the material (re-)processable: the so-called reclaiming process. In this process, either sulfur crosslinks connecting the polymer chains or carbon-carbon bonds in the polymer backbone are broken. The first mechanism is preferred, as the backbone of the polymer remains intact. Scission can be obtained by heat, shear or chemical reactions. Basically, processes of rupturing the rubber network by crosslink or main-chain scission can be classified into five main groups. †¢ Thermal reclaiming; †¢ Thermo-mechanical reclaiming; †¢ Mechano-chemical reclaiming; †¢ Reclaiming by radiation, and †¢ Microbial reclaiming. In actual practice, combinations of thermal and mechanical reclaiming are mostly used, with in some cases the addition of a devulcanization aid for chemical reclaiming. 1. 1-Thermal Reclaiming For this kind of processes, heat (often combined with addition of chemicals) is used to break the sulfur bonds and thus to plasticize the rubber. Hall patented in 1858 one of the oldest and most simple processes in the rubber reclaiming industry, the Heater or Pan process (Oil law). In this process, finely ground natural rubber powder is mixed with oils and reclaiming agents and treated with high or medium pressure steam at temperatures varying from 170 °C to 200 °C. The reclaiming time is long and the homogeneity of the reclaim is low, but this process is able to reclaim a large number of polymers: natural rubber (NR), styrene-butadiene rubber (SBR), chloroprene rubber (CR), acrylonitrile-butadiene rubber (NBR) and butyl rubber (IIR) and the equipment is rather inexpensive. The use of the heater or pan process became less popular after Marks patented the Digester or Alkali process in 1899. The fibers of the rubber scrap, remnants of the tire carcass, were first removed by mixing it with alkali, water, plasticizing oils and, if needed, chemical peptizers. The mixture was heated in a jacketed, agitator equipped autoclave to 180-210 °C. The most important disadvantage of this process is the pollution generated by the chemicals. Modifications of this process minimized the pollution, but increased the reaction times. Processes with short reaction times are for example the High Pressure Steam processes or the Engelke process. In the first process, a fiber-free, coarse ground rubber is mixed with reclaiming agents, and reclaiming is done in a high-pressure autoclave at approximately 280 °C. In the latter process, coarse ground rubber scrap is mixed with plasticizing oils and peptizers and is put into small autoclaves. The material is heated to very high temperatures for a short period of 15 minutes, after which it is lead through refiners (mills with very narrow gaps) and strainers. . 1. 1 – Steam With or Without Chemicals (Digester, DD-CR, HTDD-CR) Steam devulcanization of crumb rubber uses a steam vessel equipped with an agitator for continuous stirring of the crumb rubber while steam is being applied. There are two variants of the basis steam process, namely, â€Å"wet† and â€Å"dry. † The wet process uses caustic and water mixed with the rubber crumb, while the dry proce ss uses only steam. If necessary, various reclaiming oils may be added to the mixture in the reaction vessel. In one case, a wet process using diaryl disulfide and reclaiming oils with saturated steam at 190 °C (374 °F) was fed finely ground NR and synthetic rubber scraps. A charge of about 440 lbs. was partially devulcanized after 15 to 17 hours of processing. This process required 12 hours at ambient temperature for pre-treatment and 3 to 5 hours for steam or high temperature treatment (Adhikari, et al. , 2000). The dry process digester has the advantage of generating less pollution than the wet process. Scrap rubber containing natural and synthetic rubbers can be reclaimed by the steam digestion process. Reclaiming oil used for this process has molecular weights between 200 and 1000, consisting of benzene, alkyl benzene, and alkylate indanes. A generic processing diagram for steam devulcanization is shown in Figure A. Figure A. Schematic Diagram of a Steam Devulcanization System Devulcanized Rubber Dehydrating System Steam Reactor Rubber Crumb Chemical(s) Liquid By-Product 1. 2 – Thermo-Mechanical Reclaiming The thermo-mechanical reclaiming processes make use of shearing forces to plasticize the rubber. Energy is introduced into the materials, resulting in a significant temperature increase, high enough to cause thermal degradation. The Lancaster-Banbury process is one of the oldest processes. Fiber-free coarse ground rubber scrap is mixed with reclaiming agents and sheared in a high speed, high-pressure internal mixer. When a continuously working, multiscrew devulcanizer is used instead of the internal mixer, the process is called the Ficker reclaiming process. One of the first continuous reclaiming processes is the so-called reclaimator process. This is basically a single screw extruder that has been adapted to reclaim fibre-free rubber scrap in very short extrusion times. The short extrusion times make this method suitable for SBR, that tends to harden when longer recycling times are applied. Another mechanical reclaiming process is the De-Link process. In this process finely ground rubber powder is mixed with the De-Link masterbatch (DeVulc) : a zinc salt of dimethyldithiocarbamate and mercaptobenzothiazole in a molar ratio of 1:1 to 1:12, dispersed in thiols and activated by stearic acid, zinc oxide and sulfur. Advantages of the process are its simplicity and the fact that standard rubber equipment is used. No evidence is available to demonstrate that the De-Link process is used beyond laboratory or pilot scale. The Toyota process is another development of mechanical reclaiming. In this process a mixture of ground rubber, virgin rubber, oils and a devulcanization aid is masticated on a two-roll mill or in an extruder. Mechanical devulcanization is achieved through the repeated deformation of rubber particles under specific conditions of temperature and pressure. The result is a devulcanized rubber, ready for further processing. Toyota developed another continuous process, Toyota Gosei (TG) combining pulverization, reclaiming and deodorization. The rubber waste has to be ground to a particle size of 5-10 mm before it can be fed into a â€Å"modular screw-type reactor† with a pulverization zone and a reaction zone. The operating temperature is in the range of 100-300 °C and 100-900 rpm screw speeds are applied, the process requires about 100 Kw (kilowatts) to process 200 to 300 kg (kilograms)/hr of rubber, or approximately 0. 4 kW/kg. By manipulating screw configuration and rotational speed, and processing temperature, researchers are able to control the duration of the treatment. In this way they can, to some extent, control the properties of the devulcanizate. The TG process has been primarily, if not exclusively, used to devulcanize specific types of rubber compounds, such as NR and SBR. 1. 3 – Mechano-Chemical Reclaiming Mixing of the rubber powder with a peptizer (chemicals used to reduce the viscosity of NR) and a reclaiming agent prior to the mechanical breakdown of the material improves the reclaiming process. The devulcanization aid is supposed to selectively break the sulfur crosslinks in the rubber network. This chemical breakdown is combined with input of thermal and/or mechanical energy, as the rate of this process is sufficiently high only at higher temperatures. The most common devulcanization aids are disulfides, e. g. aryl disulfides or diphenyl sulfides, thiophenols and their zinc salts and mercaptanes. These chemical compounds are radical scavengers: they react with the radicals generated by chain- or crosslink scission and prevent recombination of the molecules. Typical concentrations for the reclaiming agents are 0. 5 to 4 wt%. Suitable peptizers are aromatic and naphthenic oils with a high boiling point. Figure B. Schematic Diagram of a Chemical Devulcanization System Devulcanization Agent Rubber Crumb Mixer Heated Extruder Devulcanized Filter Dryer Rubber Liquid By-Product Unfortunately, a detailed accounting of test materials, performance parameters, and conditions is lacking, thus inhibiting the extent of interpretation of the data. Comparisons of data are primarily limited to comparing the properties of virgin rubbers with compounds containing the virgin and devulcanized material at concentrations of about 30 percent devulcanized material. As shown by the data in the table, the properties of the mixtures containing devulcanized material are in general moderately lower than those of their virgin counterparts. The reported data reflect two different types of chemical devulcanization technologies. Table 2. Properties of Waste Tire Rubber Devulcanized Using Chemical or Chemical/Mechanical Technology Generic Technology Technology Surrogate Test Rubber Compound s % Devulc (or Ground) Mat'l Mooney Viscosity (ML-4 @ 212 °F) Tensile Strengt h (lbs/in2) 300% Modulus (lbs/ in2) Elongation to Break (%) Chemical STI-K Polymers DeLinka NR 0 61. 9 4,270 1,987 534 NR w/devulc NR 30 72. 3 4,020 2,151 489 Virgin SBR (1520) 0 96. 6 3,880 3,059 358 SBR (1520) w/devulc SBR 30 109. 2 3,580 2,923 345 Chemical/ Mechanical LandStar/ Guangzhou Research Instituteb NR 100 28. 4 680 SR 100 17. 2 514 AMRc Powder (devulc. additive) 100 23. 9 640 Tread Tire Compoundd 0 20. 3 772 28. 6 19. 7 628 Light Duty Truck Tire Compounde 0 23. 8 536 28. 6 20. 5 500 1. 4 – Reclaiming by Irradiation Bond type Dissociation energy (KJ/mol) C-C 349 C-S 302 S-S 273 Polysulfidic 253 Table 3. Typical bond energies 1. 4. 1 – Ultrasonic Rubber devulcanization by using ultrasonic energy was first discussed in Okuda and Hatano (1987). It was a batch process in which a small piece of vulcanized rubber was devulcanized using 50 kHz ultrasonic waves after treatment for 20 minutes. The process apparently could break down C-S and S-S bonds, but not carbon-carbon (C-C) bonds. The properties of the revulcanized rubber were found to be very similar to those of the original vulcanizates. One continuous process for devulcanization of rubbers is based on the use of high-power ultrasound electromagnetic radiation. This is a suitable way to recycle waste tires and waste rubbers. The ultrasonic waves, at certain levels, in the presence of pressure and heat, can quickly break up the three-dimensional network in crosslinked, vulcanized rubber. The process of ultrasonic devulcanization is very fast, simple, efficient, and it is free of solvents and chemicals. The rate of devulcanization is approximately one second. This may lead to the preferential breakage of sulfidic crosslinks in vulcanized rubbers. (Isayev, 1993; Yu. Levin, et al. , 1996; Isayev, et al. , 1997; Yun, et al. , 2001; Yun & Isayev, April 2003). Under a license from the University of Akron for the ultrasonic devulcanization technology, NFM Company of Massillon, Ohio, has built a prototype of the machine for ultrasonic devulcanization of tire and rubber products (Boron, et al. 1996; Boron, et al. , 1999). It was reported that retreaded truck tires containing 15 and 30 weight percent (percent by weight) of ultrasonicallydevulcanized carbon black-filled SBR had passed the preliminary dynamic endurance test (Boron, et al. , 1999). Extensive studies on the ultrasonic devulcanization of rubbers, and some preliminary studies on ultrasonic decrosslinking of crosslin ked plastics, showed that this continuous process allows recycling of various types of rubbers and thermosets (Isayev, 1993; Hong & Isayev, 2002 (pp. 160–168); Shim, et al. 2002; Shim & Isayev, 2003; Gonzalez-de Los Santas, et al. , 1999). As a consequence of the process, ultrasonically-devulcanized rubber becomes soft, therefore enabling this material to be reprocessed, shaped, and revulcanized in very much the same way as virgin rubber. This new technology has been used successfully in the laboratory to devulcanize ground tire rubber (commonly referred to in the industry as GRT) (Isayev, et al. , 1995; Yun, et al. , 2001; Boron, et al. , 1996), unfilled and filled rubbers N (Hong & Isayev, 2001; Yu. Levin, et al. , 1996; Isayev, et al. , 1997; Diao, et al. 1998; Shim, et al. , September 2002; Ghose & Isayev, 2003), guayule rubber (Gonzalez-de Los Santas, et al. , 1999), fluoroelastomer, ethylene vinyl acetate foam, and crosslinked polyethylene (Isayev, 1993; Isayev & Chen, 1994). After revulcanization, rubber samples exhibit good mechanical properties, which in some cases are comparable to or exceeding those of virgin vulcanizates. Structural studies of ultrasonically-treated rubber show that the breakup of chemical crosslinks is accompanied by the partial degradation of the rubber chain; that is, the C-C bonds (Isayev, et al. , 1995; Tukachinsky, et al. 1996; Yu. Levin, et al. , 1997 (pp. 641–649); Yushanov, et al. , 1998). The degree of degradation of C-C bonds can be substantial, depending on conditions. The mechanism of rubber devulcanization under ultrasonic treatment is presently not well understood, unlike the mechanism of the degradation of long-chain polymer in solutions irradiated with ultrasound (Suslick, 1988). Ultrasonic devulcanization also alters the revulcanization kinetics of rubbers. The revulcanization of devulcanized SBR appeared to be essentially different from those of virgin SBR (Yu. Levin, et al. , 1997, pp. 120–1 28). The induction period is shorter or absent for revulcanization of devulcanized SBR. This is also true for other unfilled and carbon black-filled rubbers such as ground rubber tire (GRT), SBR, natural rubber (NR), ethylene propylene diene monomer (EPDM), and butadiene rubber (BR) cured by sulfur-containing curative systems, but not for silicone rubber cured by peroxide. Ultrasonically-devulcanized rubbers consist of sol and gel. The gel portion is typically soft and has significantly lower crosslink density than that of the original vulcanizate. Due to the presence of sol and soft gel, the devulcanized rubber can flow and is subject to shaping. Crosslink density and gel fraction of ultrasonically-devulcanized rubbers were found to correlate by a universal master curve (Yushanov, et al. , 1996; Diao, et al. , 1999; Yushanov, et al. , 1998). This curve is unique for every elastomer due to its unique chemical structure. In a comparative analysis of ultrasonically reclaimed unfilled SBR, NR and EPDM rubbers, it was found that it was more difficult to reclaim EPDM than NR and SBR. Reclaiming of EPDM roofsheeting resulted in a good quality reclaim, which after revulcanization showed more or less equal mechanical properties compared to the virgin compound. The surface smoothness of the revulcanized compounds could be controlled by the process conditions. Most companies marketing ultrasonic devulcanization technologies are utilizing very similar technologies involving cold feed extruders and varying physical arrangements of ultrasonic equipment. Ultrasonic devulcanization technology is actually composed of a â€Å"devulcanization system†Ã¢â‚¬â€ namely, extrusion and ultrasonic processing. Two key differences in some cases are the equipment and materials used to generate the ultrasonic energy required for the process, and the positioning of the transducer(s) relative to the extruder. Two different arrangements of ultrasonic devulcanization systems are shown in Figures C and D. In this type of devulcanization system, size-reduced rubber particles are loaded into a hopper and are subsequently fed into an extruder. The extruder mechanically pushes and pulls the rubber. This mechanical action serves to heat the rubber particles and softens the rubber. As the softened rubber is transported through the extruder cavity, the rubber is exposed to ultrasonic energy. The resulting combination of heat, pressure, and mechanical mastication is sufficient to achieve varying degrees of devulcanization. The time constant of the devulcanization process takes place in seconds. Essentially all of the rubber entering the process is discharged from the extruder in semi-solid product stream. Process losses would be primarily those due to emissions of fine particulates or of gases, if any, generated due to the mechanical and thermal processes occurring during the devulcanization process. After exiting through the extruder die, the rubber is passed through a cooling bath and then dried. Figure C. Schematic Diagram of an Ultrasonic Devulcanization System Showing a Mid- Extruder Location for the Ultrasonic Subsystem Ultrasonic Processing Zone Cooling Bath Devulcanized Rubber Extruder Rubber Crumb Feed Hopper Figure D. Schematic Diagram of an Ultrasonic Devulcanization System Showing the Ultrasonic Subsystem Located at the Discharge End of the Extruder Ultrasonic Processing Zone Cooling Bath Devulcanized Rubber Feed Hopper Extruder Rubber Crumb Table 4. Properties of Waste Tire Rubber Devulcanized Using Ultrasonic Technology Technology Surrogate Test Rubber Compound s % Devulc or (Ground) Mat'l Mooney Viscosity (ML-4 @ 212 °F) Tensile Strength (lbs/in2) 100% Modulus (lbs/ in2) 300% Modulus (lbs/ in2) Elongation to Break (%) U of Akron SBR 1848a 0 2,415 740 780 SBR (1848) w/devulc SBRa 10 1,075 790 540 SBR (1848) w/whole train reclaima (10) 1,940 760 660 SBR (1848) w/30 mesh buffingsa (10) 1,440 780 480 100% NR (SMR CV60) & 0% SBR (23. 5% bound styrene, and Duraden 706)b 0 3,263 116 670 NR (SMR CV60) & 25% SBR (23. 5% bound styrene, and Duraden 706)b 0 1,885 123 600 NR (SMR CV60) w/devulc SBR (23. 5% bound styrene, and Duraden 706)b 25 580 123 380 NR (SMR CV60) & 50% SBR (23. 5% bound styrene, and Duraden 706)b 0 406 131 390 Technology Surrogate Test Rubber Compound s % Devulc or (Ground) Mat'l Mooney Viscosity (ML-4 @ 12 °F) Tensile Strength (lbs/in2) 100% Modulus (lbs/ in2) 300% Modulus (lbs/ in2) Elongation to Break (%) NR (SMR CV60) w/devulc SBR (23. 5% bound styrene, and Duraden 706)b 50 363 123 320 NR (SMR CV60) & 75% SBR (23. 5% bound styrene, and Duraden 706)b 0 363 145 295 NR (SMR CV60) w/devulc SBR (23. 5% bound styrene, and Duraden 706)b 75 276 131 250 100% SBR (23. 5% bound styren e, and Duraden 706)b 0 290 152 200 100% SBR (23. 5% bound styrene, and Duraden 706)b 100 290 138 180 Table 5. Percent Change from Virgin with Selected Devulcanization Rubber Formulations Test Rubber Compounds (grade) Parts or % % Devulc. or (Groun d) Mat'l. Hardnes s Shore Tear Strengt h Tensile Strengt h 100% Modulu s 300% Modulu s Elongatio n to Break Chemical STI-K Polymers DeLinka NR w/devulc NR 30 -5. 9% 8. 3% -8. 4% SBR (1520) w/devulc SBR 30 -7. 7% -4. 4% -3. 6% Kyoto Universityb Truck tire (93 NR+ 7 BR) 84 NR+ 6 BR + 20 devulc 18 8. 1% -2. 3% 2. 6% 0. 0% 74 NR+ 6 BR + 40 devulc 33 12. 9% -11. 9% 28. 2% -17. 4% 65 NR + 5 BR + 60 devulc 46 11. 3% -19. 1% 23. 1% -13. 0% LandStar/Guangzhou R Ic 100 SIR 10 + 50 devulc SIR vs. Case 1 33 4. 3% -23. 7% 6. 7% -6. 7% SIR vs. Case 2 33 6. 5% -23. 0% 11. 5% -8. 6% Tread Tire Compound 0 NR + 30 SR + 20 CIS-BR +40 AMR 28. 6 6. 7% -17. 3% -3. 0% -18. 7% Light Duty Truck Tire Compound 30 NR + 70 SR + 0 CIS-BR + 40 AMR 28. 6 1. 6% -10. 9% -13. 9% -6. 7% Retread Tire Compound c65 NR + 35 SR +40 AMR 28. 6 6. 3% -8. 6% -10. 3% -16. 8% Ultrasonic University of Akrond Versus Akrochem SBR (1848) SBR w/devulc SBR 10 -55. 5% 6. 8% -30. 8% Test Rubber Compounds (grade) Parts o r % % Devulc. or (Groun d) Mat'l. Hardnes s Shore Tear Strengt h Tensile Strengt h 100% Modulu s 300% Modulu s Elongatio n to Break SBR w/whole Tire Reclaim 10 -19. 7% 2. 7% -15. 4% SBR w/30 Mesh Buffings 10 -40. 4% 5. 4% -38. % Natural Rubber and SBR versus devulc Base 100% NR (SMR CV60) & 0% SBR (23. 5% bound styrene, and Firestone Duraden 706) 0 Add 25% SBR, 75% NR 0 -42. 2% 6. 3% -10. 4% Devulc SBR replaces SBR 25% devulc SBR, 75% NR 25 -69. 2% 0. 0% -36. 7% 50% devulc SBR, 50% NR 50 -10. 7% -5. 6% -17. 9% 75% devulc SBR, 25% NR 75 -24. 0% -10. 0% -15. 3% SBR versus devulc SBR 100% devulc SBR 100 0. 0% -9. 5% -10. 0% Heavy carbon-blacked rubber is the hardest to devulcanize, and silica, or other mineral-filled EDPM, is the easiest. Reincorporation of the devulcanized rubber is typically in the 20 to 40 percent range. Devulcanized single-product rubber applications are wide ranging. The reclaimed product may be reintroduced into the same end product or one with more tolerant performance characteristics for the devulcanized rubber. Devulcanized rubber seems to have advantages in bonding, strength, and tread integrity above the properties of crumb rubber, which acts only as a â€Å"rubber†-like filler. According to one developer of a devulcanization process, about 3 to 10 percent of the final product can be blended into virgin material before performance properties are affected. Variations of a few percent are reported by developers of devulcanization when they vary process run conditions. Run-to-run variations are normally acceptable. Devulcanized single rubber products have a much lower degree of degradation than multiple rubber mixtures with devulcanized rubber. Virgin single-grade SBR—or natural rubber replacement with devulcanized material shown by the STI-K and the University of Akron datasets —has, at worst, a reduction of 10 percent in tensile strength, modulus, or elongation. In some cases, the addition of devulcanized rubber causes a major reduction in performance of some properties, along with improvements in one or two properties (hardness and modulus). Because the modulus is the measure of deformation—that is, tension (stretching), compression (crushing), flexing (bending), or torsion (twisting). Similarly, the increase in hardness could be an improvement or detraction, depending on the application. The devulcanized rubber properties displayed are not necessarily optimized for a specific end use. Formulators will likely be able to incorporate devulcanized rubber along with other formulation components to achieve a higher level of final product performance. Key product performance variables are level of contamination, number of rubber types in the rubber mixtures, and additives used by the formulations. The effect of additives was discussed previously under â€Å"Product Characteristics. † The number of types of rubber in waste tires is one of the most important factors affecting quality of devulcanized waste tire rubber. Optimizing a devulcanization process is very difficult when more than one type of rubber is involved. Depending on the process used, process conditions, the material, and the blending level of the devulcanized rubber, most properties will be reduced by a few percent to more than two-thirds of those of the virgin material. In situations where the devulcanized rubber properties are within 10 percent of the original rubber material, blending would seem to be an attractive opportunity that offers the potential of adding a low-cost recycled substitute. The best operating model for devulcanizers of single rubber formulation is a dedicated devulcanization line (or long run) of specific rubber. Smaller volumes of single formulations require incurring extra costs for downtime and lost product caused by the cleanout between runs. The devulcanized rubber itself and some of its additives and fillers—such as carbon black— presumably add value. These fillers take the place of new additives and fillers that would otherwise be necessary. 1. 4. 2 – Microwave Microwave technology has also been proposed to devulcanize waste rubber (Fix, 1980; Novotny, et al. 1978). This process applies the heat very quickly and uniformly on the waste rubber. The method employs the application of a controlled amount of microwave energy to devulcanize a sulfur-vulcanized elastomer— containing polar groups or components—to a state in which it could be compounded and revulcanized into useful products such as hoses. The process requ ires extraordinary or substantial physical properties. On the basis of the relative bond energies of C-C, C-S, and S-S bonds, the scission of the S-S and carbon-sulfur crosslinks appeared to take place. However, the material to be used in the microwave process must be polar enough to accept energy at a rate sufficient to generate the heat necessary for devulcanization. This method is a batch process and requires expensive equipment. Figure E. Schematic Diagram of a Microwave Devulcanization System Rubber Crumb Microwave Unit Devulcanized Rubber Cooling System 1. 5 – Microbial Reclaiming Thiobacillus-bacteria are able to oxidise the sulfur in polysulfonic bonds to sulphate. This reaction is limited to a surface layer of the rubber with a thickness of less than 1 ? and the oxidation takes several weeks. The thiophilic bacteria Sulfolobus Acidocaldarius is able to split carbonsulfur bonds in a stepwise oxidation reaction of the carbon-bound sulfur into a sulfoxide, a sulfone and finally to a sulphate8, 9. The disadvantage of these processes is the low devulcanization rate. Apparently, these types of biological devulcanization processes are exclusively or primarily limited to the surface layers of the elastomers (Christiansson, et al. , 1998). This circumstance may explain the overall low rates of desulfurization based on total mass processed. Figure F. Schematic Diagram of Biological Devulcanization System Microorganisms and Host Media Mixer/ Reactor Rubber Crumb Devulcanized Rubber Dryer Filter By-Product Gases Liquid By-Product Chapter2 – Cost Analysis Given the lack of information in the literature, the cost estimates are based on a synthesis of information and data from multiple sources for a given generic type of technology; The analysis was generally performed by determining the costs (capital and operating and maintenance) of the processes and equipment described in the available literature. The cost analyses were conducted for three technologies that use different processing approaches: chemical, ultrasonic, and mechanical. * The key processing elements of each of these technologies have been previously described in this report, and they serve as the primary basis of estimating capital and operating and maintenance costs. The data in Table 6 summarize the capital costs and operating and maintenance costs for the technologies analyzed. The data for the capital cost analysis include an allowance for engineering services for the construction of the facility. The information shows that the capital costs for the processes vary from about $92,000 to about $166,000. ** Insufficient technical information and data were found during the study to enable reliable cost analyses for other devulcanization technologies. Table 6. Estimated Unit Costs for the Production of Devulcanized Rubber Item Mechanical Chemical Ultrasonic Capacity (lb/hr) 100 75 75 Capital Cost ($) 92,000 166,000 163,000 O Cost ($) 135,000 172,000 136,000 Amortized Capital and O ($) 143,000 186,000 150,000 Amortized Unit Cost ($/lb) 0. 7 1. 2 1. 0 Interest rate: 6% per year; Amortization period: 20 years Similarly, the data in the table indicate that the operating and maintenance costs for facilities of this type range from about $135,000 to $172,000. The operating cost estimates include the cost of crumb rubber feedstock for each of the processes. Based on the relative small size of the facilities, the costs of the rental of a building for processing in operating and maintenance are included. This eliminated the cost of building a structure. As shown in the Table, the estimated amortized costs for producing devulcanized rubber are: $1. 0/lb for the ultrasonic process, $1. 2/lb for the chemical process, and $0. 7/lb for the mechanical process. The analysis used an interest rate of 6 percent per year and an amortization period of 20 years. Due to uncertainties represented by the lack of detailed technical data and operating history for the technologies, the accuracy of the cost estimates is +/- 30 percent. As mentioned earlier, these costs reflect production at low capacities. Some reduction in unit cost would likely occur due to economies of larger scale production. However, estimating reduction in unit cost is difficult because of the lack of data relating to production costs to different levels of throughput capacity for particular devulcanization technologies. For the size of operations considered in this analysis, labor costs are a substantial portion of the production costs. It is very difficult, however, to estimate the magnitude of any potential reductions in unit labor costs that might occur if processing capacities were increased substantially. All circumstances considered, any estimates of commercial production costs for devulcanization of waste tire rubber are highly speculative at best. The best estimate of the study team is that perhaps production costs could be reduced by 25 to 30 percent if processing capacities were increased by a factor of approximately 5 to 10. The estimates of processing costs developed in this study do not include the costs of pollution control. The chapter lists the types of emissions that could be expected. The difficulty of permitting such a process and the cost of compliance with environmental regulations may comprise a significant barrier to the implementation of this technology. Conceivably, pollution control costs could add 10 to 30 percent to the cost of devulcanization. The difficulty of permitting—and the cost—would be a function of the type of devulcanization technology, the processing rates, and other factors. In general, the expectation is that the cost of environmental control systems for chemical devulcanization systems would be greater than that for ultrasonic or mechanical processes. The composition of rubber and additives that are used in rubber compounds in the manufacture of vulcanized rubber can and do have a dramatic effect on the properties of materials manufactured from devulcanized rubber. Apparently, the inferior properties of some poorly (inadequately) devulcanized rubber can be compensated for by the addition of chemicals and the adjustment of operating conditions, among other remedies. In many cases in the literature, this situation is not addressed or discussed. Consequently, comparing devulcanization technologies is difficult. From most of the literature descriptions of the processes, what happens to the sulfur and other vulcanization chemicals during the various processes is unclear. Chapter 3 – Environmental Analysis Little information is available in the literature on the environmental effects associated with waste tire devulcanization technologies. The lack of information apparently exists because business developers and researchers have concentrated their efforts primarily on technology improvements and achieving satisfactory properties for devulcanized rubber, an estimation of emission rates and a detailed environmental analysis are therefore not possible. However, using data and information from some other types of tire manufacturing processes (for example, extrusion of rubber) and the characteristics of vehicle tires, a qualitative analysis was performed. The environmental analysis described subsequently is limited to chemical and ultrasonic devulcanization and assumes that control of emissions would be required. 3. 1 – Chemical technology Chemical devulcanization processes are usually batch processes that involve mixing crumb rubber with chemical reactants at a specific temperature and pressure. Once the design reaction time has elapsed, the contents are then rinsed, filtered, and dried to remove any remaining unwanted chemical components. The product can then be bagged or otherwise processed for resale. A block flow diagram of a generic chemical devulcanization process is illustrated in Figure G, showing the raw material feed is crumb rubber. The crumb rubber is mixed with one or more devulcanization agents. Chemical agents identified as devulcanization agents are listed in Table 8. During processing in the batch reactor, vapors are released that must be collected and treated before release to the ambient atmosphere. Typical types of vapors that might be emitted from a batch reactor are listed in Table 9. The chemicals that would be vented from the batch reactor are dependent on the characteristics of the waste tire feedstock and on the chemical agent(s) used in devulcanizing the crumb rubber. For example, if disulfides are used in the process, they could result in formation of hydrogen sulfide (H2S) or methyl or other mercaptans (RSH). If the chemical agent orthodichlorobenzene is used, chlorinated hydrocarbons could potentially be released in the form of air emissions. Methyl iodide is volatile, and if used as a devulcanization agent, it could be vaporized. Since tire manufacturing utilizes zinc oxide and zinc carbonate, chemical devulcanization might also produce airborne metal particulates. Once the batch is fully processed, the reactor is vented. The vent gases are treated prior to release to the atmosphere. The vapors cannot be treated by vapor phase carbon because these chemicals will plate out and blind the carbon, making it ineffective. Instead, the vapor from the batch reactor needs to be thermally oxidized. At the high exit temperatures, typically as high as 2000 °F (1100 °C), the thermal oxidizer vent gases need to be cooled in a quench tower to approximately 300 °F (150 °C). Then, to remove any metals or other particulate, the vent gases are piped to a baghouse. Because of the high thermal oxidizer temperatures, methyl mercaptans (RSH) or hydrogen sulfide (H2S) from the crumb rubber is oxidized to sulfur dioxide (SO2). Therefore, downstream of the baghouse, a scrubber is required to remove sulfur dioxide (SO2), as shown in Figure G. Scrubbed vent gases are then released to the atmosphere. In addition to the scrubber vent gases described above, liquid waste is generated from the scrubber. This liquid stream contains sodium sulfate (Na2SO4). This liquid waste can be disposed in receiving waters such as a river, stream, or bay. However, discharging to receiving waters will require a significant amount of treatment equipment and eventually a permit. As seen in Figure G, the devulcanized rubber is moved from the batch reactor to a separator by a heated extruder. Liquid that drips off the devulcanized rubber is removed in the separator and eliminated by feeding it to the same thermal oxidizer as the vent gases from the batch reactor. After the liquid has dripped off the devulcanized rubber in the separator, any remaining moisture is removed in the dryer. Fired dryers are typically fueled by natural gas burners. Dryer vent gases are piped to the common thermal oxidizer. Based on the concentration of solids in the scrubber effluent, processing the scrubber effluent through a filter press to dewater the solids may be necessary and cost-effective. Filter-pressed dewatered solids are called â€Å"filter cake. Filter cake might require disposal in a hazardous waste site. Even though the waste disposal site may accept the scrubber effluent water, the economics may favor installation and use of a filter press. This is necessary to dewater the solids due to the high cost of disposal of liquid waste. Figure G. Block Flow Diagram of a Chemical Devulcan ization System Solids H2O Batch Reactor Heated Extruder Separator Crumb Rubber Devulcanization Agent 300 ° F Liquids Devulcanized Rubber Dryer Natural Gas Vapors Thermal Oxidizer Quench Tower Baghouse Natural Gas Scrubber 2000 ° F 300 ° F H2O Air Emissions Air Emissions to Atmosphere Effluent Water Table 7. Tire Raw Materials Polymers Antiozonants Natural Rubber (polyisoprene) 2,2,4-trimethyl-1,2-dihydroquinoline (polymer) Styrene-Butadiene Rubber (SBR) n,n-(1,3-dimethylbutyl)-pphenylenediamine cis-Polybutadiene copolymer paraffinic wax Vulcanizing Agents Antioxidants Sulfur Alkylphenols Tetra-methyl thiurame sulfide Resorcinol Accelerators 2,6-Diterbutylhydroquinone Diphenylguanidine Retarders 2-Mercaptobenzothiazole n-Cyclohexylthiophthalimide n-Cyclohexyl-2-benzothiazolylsulfenamide Plasticizers 2-(n-Morpholinyl)-mercaptobenzothiazole Aliphatic oil Hexamethylenetetramine Aromatic oil Activators Naphthenic oil Zinc oxide Di-(2-ethylhexyl)-phthalate Zinc carbonate Extenders Stearic acid Silica gel Carbon black Table 8. Chemical Agents Used in Chemical Tire Devulcanization Processes Triphenyl phosphine Sodium di-n-butyl phosphite Thiol-amine reagents (specifically propane-thiol/piperidine, dithiothreitol, and hexane-lthiol) Lithium aluminum hydride Phenyl lithium Methyl iodide Hydroxide with quaternary ammonium chloride as a catalyst Orthodichlorobenzene Diphenyldisulphide Diallyl disulfide Toluene, naphtha, benzene, and/or cyclohexane, etc. in the presence of sodium Diamly disulfide Dibenzyl disulfide Diphenyl disulfide Bis(alkoxy aryl) disulfides Butyl mercaptan and thiopenols Xylene thiols Phenol sulfides and disulfides Alkyl phenol sulfides (for SBR) N,N-dialkyl aryl amine sulfides (for SBR in neutral or alkaline solutions) 3. 2 – Ultrasonic technology Devulcanization by ultrasonic methods may be a continuous process (see Figure H). As the figure illustrates, crumb rubber is loaded into a hopper and is subsequently fed into an extruder. The extruder mechanically pushes and pulls the rubber. This mechanical action serves to heat the rubber particles and soften the rubber. As the softened rubber is transported through the extruder cavity, the rubber is exposed to ultrasonic energy. The resulting combination of ultrasonic energy, along with the heat, pressure, and mechanical mastication, is sufficient to achieve varying degrees of devulcanization. The exposure time to the ultrasonic energy is only seconds. Essentially all of the rubber entering the process is discharged from the extruder in a semi-solid product stream. Process losses would be primarily emissions of fine particulate or of gases, if any, resulting from the mechanical and thermal applications occurring during devulcanization. Since the typical operating temperature of an ultrasonic devulcanization reactor is about 230 °F (110 °C), less vapor emission would be expected than from chemical devulcanization. Furthermore, since no chemicals are added to break the sulfur bonds that caused vulcanization to occur, there would likely be lower air emissions. After exiting through the extruder die, the rubber is passed through a cooling bath and then dried. Vented vapors would need to be treated by one of two methods. One method would be to use a small thermal oxidizer. The design of the thermal oxidizer, baghouse, and scrubber would be similar to that described previously for chemical devulcanization. However, the physical size of the oxidizer would be smaller, and the baghouse and scrubber would be larger. A second method to treat the vent gases exiting the ultrasonic devulcanization reactor would be use of vapor phase carbon. In this method, due to the lower operating temperatures of the ultrasonic process, vent gas exiting the ultrasonic zone would have to be heated above the dew point temperature. If this elevation in temperature is not accomplished, the vent gases could condense on the surface of the carbon and thus blind the bed. In other words, adsorption sites on the surface of the carbon would be ineffective, and vent gases would exit the carbon bed untreated. If vapor phase carbon were to be used, the capital cost would be less than that of a thermal oxidizer. However, carbon is not very efficient. Weight loading can be approximately 10 weight percent—in other words, adsorbing ten pounds of vent gas contaminants for every 100 pounds of carbon used. Use of carbon will have a relatively high operating cost. Also, the disposal of spent carbon can be very expensive. This is especially true if the spent carbon requires disposal at a hazardous waste disposal site. Even if the carbon is regenerated on-site, adsorption efficiency decreases after each regeneration. Typically, carbon can only be regenerated ten times. For illustration purposes, Figure H indicates the use of vapor phase carbon. Devulcanized rubber exiting the ultrasonic processing zone has to be cooled. A common method of reducing the rubber temperature is a cooling bath. The volume of cooling water used would be significant. Cooling water may become ontaminated from the process; this effluent water leaving the cooling bath has to be treated. If an air cooler such as fin fans is used in lieu of water in the cooling bath, the volume of effluent liquid would be reduced. Another alternative would be to use a closed-loop cooling system, where the cooling water is cooled and returned to the process for reuse. If there is a buildup of contaminants, a small slipstream could be taken off and treated in a POTW, greatly reducing the amount of effluent that would otherwise require treatment. Figure H. Block Flow Diagram of an Ultrasonic Devulcanization System Ultrasonic Processing Zone Cooling Bath Devulcanized Rubber Feed Hopper Extruder Crumb Rubber Cooling Water Supply Effluent Water Heater Air Emissions Baghouse Carbon Air Emissions to Atmosphere Table 9. Potential Types of Chemical Compounds Emitted by Chemical and Ultrasonic Devulcanization Technologies Compound Probable Source Benzene Plasticizers: Aromatic oil Methylcyclohexane Plasticizers: Na phthemic oil Toluene Plasticizers: Aromatic oil Heptane Plasticizers: Aliphatic oil 4-Vinylcyclohexene Polymers: Natural Rubber (polyisoprene), styrene-butadiene rubber (SBR), cis- Polybutadiene Ethylbenzene Plasticizers: Aromatic oil Octane Plasticizers: Aliphatic oil p-Xylene Plasticizers: Aromatic oil Styrene Polymers: styrene-butadiene rubber (SBR) Nonane Plasticizers: Aliphatic oil 1,4-Cyclohexadiene-1-isopropyl-4- methyl Polymers: Natural Rubber (polyisoprene) Isopropylbenzene Plasticizers: Aromatic oil Cyclohexene-1-methyl-3-(1- methylvinyl) Polymers: Natural Rubber (polyisoprene) Propylbenzene Plasticizers: Aromatic oil Benzaldehyde Polymers: styrene-butadiene rubber (SBR) 1-isopropyl-4-methylcyclohexane (trans) Plasticizers: Naphthemic oil 1-isopropyl-4-methylcyclohexane cis) Plasticizers: Naphthemic oil 1-isopropyl-3-methylcyclohexane Plasticizers: Naphthemic oil Decane Plasticizers: Aliphatic oil Tri-isobutylene Polymers: styrene-butadiene rubber (SBR) & cis-Polybutadiene; Plasticizers: Naphthemic oil Cyclohexene-5-methyl-3-(1- methylvinyl) Polymers: Natural Rubber (polyisoprene) Indane Plasticizers: Naphthemic oil 1-Isopropyl-4-methylbenzene Plasticizers: Aromati c oil Cyclohexene-1-methyl-4-(1- methylvinyl) Polymers: Natural Rubber (polyisoprene) 1-Isopropyl-2-methylbenzene Plasticizers: Aromatic oil Dimethylstyrene Polymers: styrene-butadiene rubber (SBR) Undecane Plasticizers: Aliphatic oil Tetramethylbenzene Plasticizers: Aromatic oil 1,2,3,4-Tetrahydronaphthalene Plasticizers: Naphthemic oil 1,3-Di-isopropyl benzene Plasticizers: Aromatic oil 1,4-Di-isopropyl benzene Plasticizers: Aromatic oil Compound Probable Source 2-Isopropyl-6-methylphenol Antioxidents: Alkylphenols Cyclohexylisothiocyanate Retarders: n-Cyclohexyl-thiophthalimide Cyclododecatriene Polymers: cis-Polybutadiene Dodecane Plasticizers: Aliphatic oil Tridecane Plasticizers: Aliphatic oil Tetraisobutylene Polymers: styrene-butadiene rubber (SBR) & cis-Polybutadiene; Plasticizers: Naphthemic oil -ter-Butylstyrene Polymers: styrene-butadiene rubber (SBR) Dimethylpropylhexahydronaphthale ne Plasticizers: Naphthemic oil Tetradecane Plasticizers: Aliphatic oil Nonylbenzene Plasticizers: Aromatic oil 2,6-Di-ter-butyl-p-quinone Antioxidents: 2,6-Diterbutyl-hydroquinone Pentadecane Plasticizers: Aliphatic oil 1,6-dimethyl-4-isopropyl-1,2,3,4- tetra-hydronaphthalene Plasticiz ers: Naphthemic oil Decylbenzene Plasticizers: Aromatic oil Di-ter-butylthiophene Plasticizers: Aromatic oil Diethyl phthalate Plasticizers: Di-(2-ethylhexyl)-phthalate Hexadecane Plasticizers: Aliphatic oil ,2-Di-tolylethane Polymers: styrene-butadiene rubber (SBR) Heptadecane Plasticizers: Aliphatic oil 2,6-Di-ter-butyl-4-ethylphenol Antioxidents: Alkylphenols Octadecane Plasticizers: Aliphatic oil 1-Phenylnaphthalene Plasticizers: Aromatic oil Di-iso-butyl phthalate Plasticizers: Di-(2-ethylhexyl)-phthalate Tridecylbenzene Plasticizers: Aromatic oil Dibutyl phthalate Plasticizers: Di-(2-ethylhexyl)-phthalate Eicosane Plasticizers: Aliphatic oil Heneicosane Plasticizers: Aliphatic oil Docosane Plasticizers: Aliphatic oil Di-(2-ethylhexyl) phthalate Plasticizers: Di-(2-ethylhexyl)-phthalate Chapter 4 – Conclusions Devulcanization of specific types of rubber and/or waste tire rubber has a long history. However, only recently have limited technical data been reported in the available literature. Usually when reported, the tested properties of devulcanized rubber compose an incomplete list. This is especially true in the interpretation of how the devulcanized product would perform during compounding, in the manufactured end product, or both. Circumstantial and anecdotal evidence indicates significant technical and economic barriers to devulcanization of waste rubber. Based on the information collected in the study, is believed that the only method of achieving bulk devulcanization, as opposed to surface devulcanization, rests with ultrasonic or microwave devulcanization methods. Of these two methods of energy application, ultrasound appears to have substantially more research and development history. An important observation is that microwave technology is not an effective or efficient way to devulcanize non-polar rubber types, which collectively compose the vast majority of the mass of rubber in waste rubbers. Because of the ability to internally devulcanize cured rubber, ultrasonically devulcanized waste tire rubber may have more desirable marketing characteristics than those of surface-devulcanizing processes under similar conditions of cost and yield. The latter processes (surface devulcanizing) include mechanical, chemical, and biological processes. However, test data and applications for ultrasonically devulcanized waste rubber are lacking in the industry, along with process cost documentation. The devulcanized rubber market is most fully developed for single product materials made from manufacturing scrap that are reclaimed for reuse in the same process or in a broader specification application. The reprocessing of single rubbers depends upon being located near a large-volume rubber products company with enough scrap and enough rubber applications to justify the devulcanization step. Devulcanization of waste rubber, despite considerable research and developmental effort, is still in an early growth stage. Devulcanization lacks adequate test data and data interpretation, and it has poorly defined end product specifications without adequately justified and defined applications and uses. Research funds appear to be most available for studying devulcanization of single rubber types, as opposed to studying rubber types with complex mixtur. In applications already using crumb rubber, devulcanized rubber can have advantages if the process combines a vulcanized rubber or other compatible material to create an integrated structure. The structure must have much better properties than those imparted by the filler role that crumb rubber frequently serves.