Thermoplastic Copolyester nancomposites for biomedical applications Research Proposal

Thermoplastic Copolyester nancomposites for biomedical applications - Research Proposal Example Nanocomposites comprise a broad class of new materials that can combine the properties of bulk phase materials with nano-dimensional phase materials. The application of these materials to biomedical devices is a subject of intense research, providing an opportunity for researchers to develop and exploit the properties of new materials to achieve markedly different catalytic, mechanical, thermal, electrochemical, optical, and electrical properties from the component materials that may be useful in the development of contemporary medical devices and drug delivery systems. Copolyester thermoplastic elastomers combine the chemical and material properties of chemically crosslinked elastomers with engineered plastics, which are often much easier and affordable to manufacture. These materials consist of multiple domains, instead of the single domain found in polyesters, and are commonly referred to as â€Å"hard† and â€Å"soft† blocks (Cella, 1973, p.727). ... These materials combine the strength and processing characteristics available to engineered plastics with the performance abilities of thermoset elastomers, with the additional benefit of attaining optimal properties without vulcanization, a factor that can significantly reduce part cost (DSM 2011, p.2). Copolyesters, like polyesters, are polymers assembled from diacids and diols whose type may be varied in order to achieve certain material properties. Copolyesters, however, contain multiple distinct monomers (Jaarsma 2004, p.1). These materials have both excellent mechanical properties that duplicate rubber and leather at a fraction of the cost, making the materials commercially interesting for a broad variety of applications (Dupont 2011, p.2-3). Relative to other available elastomers, copolymer elastomer materials offer the most consistent performance over a range of temperatures, with little variation in properties at either extremely high or low temperatures (DSM 2011, p.2). Thi s is a property particularly useful in the sterilization of medical devices, which often involves extreme temperature ranges. In order to be useful for biomedical applications, the most important material property is to withstand repeat sterilization processes that may involve gamma irradiation, high temperatures, electron beams, and ethylene oxide (EtO) treatments. In addition, a material must show excellent chemical resistance, toughness, clarity, and color stability in order to be effectively applied to biomedical applications (Jaarsma 2004, p.1). Achieving an effective biomedical nanocomposite material that fits these stringent criteria

Breakup of the Soviet Union Essay Example | Topics and Well Written Essays - 750 words

Breakup of the Soviet Union - Essay Example There were many reasons for the disintegration of USSR. Economic collapse: The cold war between the America and USSR had created a virtual battleground for the two countries in which both tried to get an advantage over the other. It initiated the race for arms and both countries tried to acquire and produce better weapons to keep the other country in line. For the USSR, the arms race created a lot of problems. A high amount of the budget was spent on the military while the industry and other sectors received only a very small share. Such a large yearly output being devoted only for the cause of military resulted in the decline of the country’s economy which finally went into stagnation. The two countries also engaged in a ‘space race’ releasing shuttles and satellites into the space to improve their technological standings. This also caused the USSR a lot of money and caused resentment among the general public as the amount was not being used to satisfy their basi c needs. A major blow to the USSR economy was also made by the change in Saudi Arabia’s oil policies.... Also the regions within the USSR like Tajikistan that had ethnic links with the Afghans did not favor the war and hence an internal unrest was born inside the USSR (The Collapse of the Soviet Union). Gorbachev's reforms: The stagnation of the country and the obsolete political system of the country forced Gorbachev to introduce new reforms that could revitalize the economy and stabilize the existing political conditions. He introduced two famous reforms namely 'glasnost' and 'perestroika' which called for freedom of speech and political reconstruction respectively. The reforms however backfired and lead to the collapse of USSR. The transparency and the freedom of speech allowed the media to talk about corruption, alcoholism, political scandals and other issues that defamed the government. As the events like Chernobyl disaster and the Afghan war began to be showed in a negative light by the media the distrust of the general public on the Soviet government gradually increased. The stor ies of political killings and massacres in individual states like Armenia instilled the spirit of freedom and peaceful protests like The Baltic way began to be held in the entire country (Spielvogel). The democratization brought in as a result of perestroika provided more authority to the public and they openly spoke against the government. Gorbachev's reforms might have been for the good of the country but it produced radical unforeseen effects and the timing was certainly not right as his reforms ultimately resulted in the disintegration of USSR. US policies: While the above three factors played the most important role in the disintegration, the role of US cannot be denied. Ronald Regan, the president of US of that time made use of the deteriorating conditions of the USSR