Thesis (M.S.)--West Virginia University, 1999. / Title from document title page. Document formatted into pages; contains xii, 101 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 87-92).

Thesis (M.S.)--Ohio University, March, 2004. / Title from PDF t.p. Includes bibliographical references (leaves 129-131).

Universiẗat, Diss., 2003--Würzburg. / Erscheinungsjahr an der Haupttitelstelle: 2003.

Universiẗat, Diss., 2003--Bayreuth.

While paraffin has the potential to be a high performance fuel for hybrid rockets, sloughing-off of portions of the fuel during the burn, fuel-liner delamination during fabrication, difficult ignition, and the escape of significant amounts of unburned paraffin droplets from the combustion chamber have hindered efforts to demonstrate superior performance in paraffinueled hybrid motors. This work investigates several methods for enhancing the performance of paraffin-based hybrid motors including the use of anti-sloughing baffles in the grain liner, ignition media to ensure repeatable and prompt engine start, improved methods for fuel grain production, and aluminum and potassium nitrate additives. The results of the tests demonstrate modest improvements in anti-sloughing and total impulse, compared to the baseline paraffin fuel grain. Difficulty achieving sufficiently repeatable results with the available commercial motor prevented some of the research goals from being completed but lead to a better understanding of the factors affecting the performance space.

Zugl.: Bochum, Univ., Diss., 2009

Made available in DSpace on 2015-07-22T20:50:13Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-11-24 / Tecidos fixados em formalina e incluídos em parafina permitem investigações retrospectivas valiosas para estudos moleculares, especialmente em estudos genéticos, nos casos em que o DNA não se encontra disponível em amostras congeladas e/ou frescas. Entretanto, de acordo com alguns autores, é difícil obter um DNA de boa qualidade, uma vez que o processo de fixação resulta na fragmentação dos ácidos nucleicos. O objetivo deste trabalho foi avaliar o DNA extraído de tecidos parafinados, após 1 e 5 anos de armazenamento, através de 3 métodos de extração. Para isso, foram utilizados o gene da β-actina (136pb), a fim de detectar a viabilidade e fragmentação do DNA extraído, e da amelogenina (X: 212pb e Y: 218pb) para diferenciação do sexo do indivíduo e viabilidade na utilização de primers com comprimento maior. O estudo envolveu 12 casos de autópsia recentes, onde amostras normais de fígado (n=10), baço (n=10) e cérebro (n=10) foram coletadas em duplicata, de modo que um grupo seguiu para o processo de fixação e inclusão em parafina, e outro grupo seguiu para o congelamento. Além disso, foram utilizados os mesmos tipos de tecidos, normais (n=10 cada), oriundos de 13 casos de autópsia armazenados por 1 ano e 15 casos armazenados por 5 anos. Após a remoção da parafina, as amostras foram submetidas às extrações com kit comercial (QIAGEN QIAamp Mini), Salting-Out e fenol-clorofórmio. O DNA extraído foi quantificado no aparelho Nanodrop® e ajustado para PCR (10ng/μl). Os produtos de PCR foram visualizados em gel de agarose a 1%. As amostras de baço e fígado apresentaram maior rendimento em relação à extração de DNA quando comparado ao cérebro, em todos os tempos. Todas as amostras arquivadas apresentaram boas condições de extração de DNA, porém deve-se levar em consideração o processo de fixação e inclusão dos tecidos, que podem comprometer a qualidade do DNA. A extração pelo fenol rendeu maior quantidade de DNA e grau de pureza em relação aos outros métodos estudados, porém o kit comercial mostrou melhores resultados quanto à amplificação do DNA obtido. Houve amplificação do gene da amelogenina em todas as amostras utilizadas, porém recomenda-se a utilização de primers menores para uma completa análise do fragmento a ser estudado. / Formalin fixed and paraffin embedded tissues provide valuable retrospective investigations for molecular studies, especially for genetic studies, when the DNA is not available in fresh and/or frozen samples. However, according to some authors, is difficult to obtain a DNA of good quality, since the fixation process results in nucleic acids fragmentation. The aim of this study was to evaluate the DNA extracted from paraffin embedded tissues, after 1 and 5 years of storage, by 3 methods of extraction. For this, the gene of β-actin (136pb) were used, to detect the viability and DNA fragmentation, and the gene of amelogenin (X: 212pb e Y: 218pb) for sexual differentiation and viability in primers with greater length. The study involved 12 recent autopsy cases, where samples of liver (n=10), spleen (n=10) and brain (n=10) were collected in duplicate, which one group followed to the process of fixation and inclusion and the other group followed to freezing. Moreover, the same kind of tissues, normal (n=10 each), from 13 autopsy cases archived for 1 year and 15 cases archived for 5 years were used. After paraffin remove, the samples were submitted to DNA extraction with commercial kit (QIAGEN QIAamp Mini), Salting-Out and phenol-chlorophorm. The DNA extracted was quantified in Nanodrop® and adjusted for PCR (10ng/μl). The PCR products were visualized in agarose gel 1%. The samples of spleen and liver showed more yield in DNA extraction than the brain samples, in all the times. All the samples archived showed good extraction conditions, however should take in consideration the fixation and embedded process, which could compromise the DNA quality. The extraction by phenol-chloroform yielded more DNA quantity and purity than the other methods. However, the commercial kit extraction showed better results in DNA amplification. The primer of the gene of amelogenin was amplified in all utilized samples, however recommends the utilization of smaller primers for a complete analyze of the fragment studied. / TEDE / BV UNIFESP: Teses e dissertações

Submitted in fulfillment of the requirements for the Master's of Technology: Chemistry, M L Sultan Technikon, 1999. / Saturated long chain hydrocarbons, such as paraffin waxes, have a large variety of applications. These applications may, however, be restricted by certain properties of the wax such as brittleness and in compounding. Cross-linking of the long chains in waxes may provide improved physical properties and hence a wider application of these waxes / M

HASEL-actuators use dielectric liquids and compliant shells as their media. This type of actuatorwould suit the actuators used as fins for soft milli robots (SOMIRO). These robots are going tobe used in aquaponic crops for studying its impact on the environment to help the farmersimprove their crops. The robots have to be soft and compliant, so the materials used for theHASEL-actuator should have the same properties. First, an automatic manufacturing method isinvestigated to find a proper way to produce these actuators. It was concluded that a processcalled the “two-layered actuator” had the most potential, where a PU film, PET film andDUALBOND glue was used to produce a well-defined HASEL-actuator by creating a cavitywithin the PU film by using a suction flask and fill the cavity with coconut oil. The cavity'sshape was two domes (3 mm in diameter) connected with a middle channel (1 mm in diameterand a length of 3 mm). The actuator had electrodes made of a curable silver paste or Galinstanwhere their potential difference is used for powering the actuation. The aim for the neededvoltage when actuating the actuators was to be below 1kV. This means that the actuators have tobe as thin and have a low Young’s modulus as possible. The silver electrodes made the actuatortoo stiff to actuate at that low voltage, so the other potential materials would be Galinstan as theelectrode and PDMS and PU film which could replace the PU and PET respectively. Dependingon the pressure used on the suction flask for fabrication of the two-layered actuator, differentheights of the cavity could be achieved. By changing the pressure to 1 kPa, it was found out thatthe lowest height of 260 µm could be achieved. Different compositions of paraffin oils wereevaluated to find a suitable dielectric liquid with the right melting temperature since the actuatoronly works when the media is in its liquid state. The sample showing highest potential had amixture of 4.4 g of a liquid paraffin oil and 1.17 g of a soft paraffin wax. The starting meltingpoint was concluded to be at 5 °C. During the voltage test of the actuators, no sign of movementcould be seen for any of the produced actuators when reaching the highest voltage of 1 kV. Thisindicates that the actuators are still too thick and stiff and needs to be improved in the future

No description available.