Linear polyamides, commonly known as Nylons, are widely used for their high melting temperatures, heat stability, toughness and abrasion resistance, allowing diverse commercial applications such as carpets, nylon stockings and automotive parts. The work here has possible ramifications for membrane production and drug delivery systems and makes a scientific contribution to the area of binary polymer/diluent systems where the polymer is semicrystalline and the diluent crystallises at a quite different temperature to the polymer. Melt blended crystalline/crystalline systems have, so far, not received the attention that amorphous/amorphous or crystalline/amorphous systems have, perhaps due to the complexity of the morphology that often results within such systems.

<p>This work describes how a fatty acid methyl ester (FAME) derived from a vegetable oil can be introduced as reactive diluent in a solvent-borne thermally cured coil-coating system. The evaluated reactive diluent, rape seed methyl ester (RME), has been evaluated both in a fully formulated clear coat system and via model studies.</p><p>A reactive diluent is a compound that acts as a solvent in the liquid paint, lowering the viscosity, and chemically reacts into the final film during cure. Introduction of a reactive diluent derived from vegetable oil give a more environmental compliant coating since a renewable material is incorporated in the coating and the amount of traditional solvent can be decreased. These positive environmental factors have increased the industrial interest.</p><p>The fully formulated clear coat studies describes how addition of reactive diluent affects rheological properties of the wet paint, film formation, incorporation, and final film properties in a hydroxyl-functional polyester/melamine coil-coating system. The coating were cured under industrial coil-coating cure conditions and analyzed with Raman, carbon-14 dating, extraction, dynamic mechanical analysis, and visually observed. Viscosity measurement of the wet paint show that RME works as a diluent. RME increase the mobility in the system enhancing the film formation process and occurrence of defect-free films. The incorporation of RME could not be confirmed by Raman analysis. However, carbon-14 dating did indicate the presence of RME that could not be extracted from the films. The appearance and mechanical properties of the films were also significantly affected by addition of RME. Dynamic mechanical analysis of the free standing films showed that the final film properties were affected by oven temperature, choice of co-solvent, and flash-off period.</p><p>Model studies were performed to further clarify how RME chemically can react through transesterification with the hydroxyl-groups of the polyester. RME and its two main components methyl oleate and methyl linoleate were reacted with primary alcohols with and without tertiary hydrogen both under low temperature (110, 130, 150, 170°C) and industrial cure conditions. The transesterification reaction was monitored with 1H-NMR and real time IR. Evaporation and side reactions, e.g. oxidation, are competing factors with the transesterification reaction. The fatty acid structure affects the conversion as a higher amount of unsaturations triggers higher degree of oxidation. The study also showed that reaction time and temperature affects the transesterification conversion, degree of side reactions, and catalyst choice.</p>

FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / Esta tese de doutorado apresenta um estudo sobre a utilizaÃÃo de dois bioprodutos, o primeiro a base de extrato lÃquido da palma forrageira gigante (Opuntia ficus indica) liofilizado e o segundo a Ãgua de coco em pà ACP-104, como diluente de sÃmen de curimatà comum (Prochilodus brevis). Este estudo foi motivado pela escassez de informaÃÃes sobre o sÃmen da espÃcie, dos bioprodutos testados e pela necessidade de desenvolver um protocolo de resfriamento e criopreservaÃÃo utilizando sÃmen de curimatà comum associados aos bioprodutos à base de palma forrageira e ACP-104. A tese està apresentada em trÃs capÃtulos. O primeiro capÃtulo trata de um artigo de revisÃo contendo as biotÃcnicas empregadas na conservaÃÃo de gametas. Nele relatam-se as tÃcnicas de resfriamento, congelaÃÃo e descongelaÃÃo de sÃmen e avaliaÃÃo morfolÃgica e computadorizada de espermatozoides de curimatà comum (P. brevis). O segundo capÃtulo objetiva a criopreservaÃÃo e anÃlise morfolÃgica dos espermatozoides de curimatà comum (P. brevis) diluÃdos em soluÃÃes a base de extrato de palma forrageira gigante (O. ficus) liofilizado, ACP (Ãgua de coco em pÃ) e soluÃÃo de glicose a 5%. Neste experimento foi utilizado o programa computacional CASA (Computer-Assisted Sperm Analyser) para analisar as propriedades de trajetÃria e velocidade dos espermatozoides para cada soluÃÃo estudada. Esta pesquisa teve como objetivo principal avaliar os efeitos da criopreservaÃÃo do sÃmen de curimatà comum (P.brevis), utilizando como diluente o extrato de palma forrageira gigante (O. ficus) liofilizado (EPFL). A metodologia empregada na criopreservaÃÃo do sÃmen de curimatÃ, utilizando os diluentes ELPF 30%; ELPF 50%, ACP-104 e Glicose 5%, permitiu a obtenÃÃo de taxas de motilidade pÃs-descongelamento superiores a 60%. O melhor meio de congelaÃÃo seminal de P. brevis, nas condiÃÃes testadas à o que utiliza a associaÃÃo do ACP-104 com o DMSO 10%. A metodologia empregada na criopreservaÃÃo do sÃmen de curimatà (P. brevis), utilizando os diluentes ELPF 30%; ELPF 50%, ACP-104 e Glicose a 5%, foram adequadas, permitindo a obtenÃÃo de taxas de motilidade pÃs-descongelamento superiores a 60%. Os resultados expressivos foram aqueles obtidos quando se utilizou a associaÃÃo do ACP-104 e DMSO 10%. Os demais tratamentos podem ser considerados num programa de reproduÃÃo assistida, jà que apresentaram desempenho dentro dos padrÃes de utilizaÃÃo de sÃmen criopreservados na espÃcie Prochilodus brevis. / This thesis presents a study on the use of two bioproducts, the first base of liquid extract of giant cactus pear (Opuntia ficus indica) lyophilized and the second the coconut powder ACP-104 as diluent semen common curimatà (Prochilodus brevis). This study was motivated by the scarcity of information about the semen of species of tested bioproducts and the need to develop a protocol for cooling and cryopreservation of semen using common curimatà associated with bioproducts based on cactus pear and ACP-104. The thesis is presented in three chapters. The first chapter is a review article containing biotechnologies employed in the preservation of gametes. Report him to the techniques of cooling, freezing and thawing of semen and morphological and computerized assessment of sperm of common curimatà (P. brevis). The second chapter aims to morphological analysis and cryopreservation of sperm of common curimatà (P. brevis) diluted in solutions based on extracts of giant cactus pear (O. ficus) lyophilized, ACP (coconut milk powder) and glucose solution 5%. In this experiment the computer program CASA (Computer-Assisted Sperm Analyser) was used to analyze the properties of trajectory and speed of sperm for each solution studied. This research aimed to evaluate the effects of cryopreservation of semen from common curimatà (P.brevis), using as diluent extract giant cactus pear (O. ficus) lyophilized (EPFL). The methodology used in sperm cryopreservation of curimatà using the diluents ELPF 30%; ELPF 50%, ACP-104 and 5% dextrose, afforded the rate of post-thaw motility higher than 60%. The best way of semen freezing P. brevis, the tested conditions is what uses the association of ACP-104 with 10% DMSO. The methodology used in sperm cryopreservation of curimatà (P. brevis) using diluents ELPF 30%; ELPF 50%, ACP-104 and 5% glucose were suitable, capable of producing rates higher post-thaw motility 60%. The significant results were those obtained when using the combination of ACP-104 and 10% DMSO. The other treatments may be considered an assisted reproductive program, as presented within the performance standards for the use of cryopreserved semen in species Prochilodus brevis.

This work describes how a fatty acid methyl ester (FAME) derived from a vegetable oil can be introduced as reactive diluent in a solvent-borne thermally cured coil-coating system. The evaluated reactive diluent, rape seed methyl ester (RME), has been evaluated both in a fully formulated clear coat system and via model studies. A reactive diluent is a compound that acts as a solvent in the liquid paint, lowering the viscosity, and chemically reacts into the final film during cure. Introduction of a reactive diluent derived from vegetable oil give a more environmental compliant coating since a renewable material is incorporated in the coating and the amount of traditional solvent can be decreased. These positive environmental factors have increased the industrial interest. The fully formulated clear coat studies describes how addition of reactive diluent affects rheological properties of the wet paint, film formation, incorporation, and final film properties in a hydroxyl-functional polyester/melamine coil-coating system. The coating were cured under industrial coil-coating cure conditions and analyzed with Raman, carbon-14 dating, extraction, dynamic mechanical analysis, and visually observed. Viscosity measurement of the wet paint show that RME works as a diluent. RME increase the mobility in the system enhancing the film formation process and occurrence of defect-free films. The incorporation of RME could not be confirmed by Raman analysis. However, carbon-14 dating did indicate the presence of RME that could not be extracted from the films. The appearance and mechanical properties of the films were also significantly affected by addition of RME. Dynamic mechanical analysis of the free standing films showed that the final film properties were affected by oven temperature, choice of co-solvent, and flash-off period. Model studies were performed to further clarify how RME chemically can react through transesterification with the hydroxyl-groups of the polyester. RME and its two main components methyl oleate and methyl linoleate were reacted with primary alcohols with and without tertiary hydrogen both under low temperature (110, 130, 150, 170°C) and industrial cure conditions. The transesterification reaction was monitored with 1H-NMR and real time IR. Evaporation and side reactions, e.g. oxidation, are competing factors with the transesterification reaction. The fatty acid structure affects the conversion as a higher amount of unsaturations triggers higher degree of oxidation. The study also showed that reaction time and temperature affects the transesterification conversion, degree of side reactions, and catalyst choice. / QC 20101117

Solvent-borne thermally cured coil-coating resins contain large amounts of volatile organic solvents in order to obtain suitable flow for film application. This work describes how the expensive and environmental hazardous volatile organic solvent content of a solvent-borne thermally cured polyester/melamine coil-coating system can be reduced by introduction of fatty acid methyl esters (FAMEs) as reactive diluents and modification of the polyester binder resin. The evaluated reactive diluents, two rape seed methyl esters (RMEs), two linseed oil methyl esters (LMEs), and a tall oil methyl ester (TOME) have been evaluated both in a fully formulated clear-coat system and via model studies. Viscosity measurements of wet paint mixtures showed that formulations with hyperbranched polyester binder hold lower viscosity than conventional polyester binder resins and that FAME works as a diluent. Fully formulated clear-coats were cured under simulated industrial coil-coating cure conditions and in a convection oven at lower temperatures respectively. FAME increases the mobility of the system enhancing the film formation process. Free-standing clear-coat films were analyzed with Raman, carbon-14 dating, extraction, dynamic mechanical analysis, and visual observation. Incorporation of FAME could not be confirmed by Raman analysis. However, carbon-14 dating indicated the presence of FAME that could not be extracted from the films. The mechanical properties of the films were also affected by the addition of FAMEs, oven temperature, choice of co-solvent, and flash-off period. Conventional film characterization tests on substrate supported coatings indicated that binder resin structure and cure conditions affect the final film properties. Model studies were performed to clarify how FAME can chemically react through transesterification with the hydroxyl-groups of the polyester. The transesterification reaction between different FAMEs and primary alcohols with and without tertiary hydrogen was monitored with 1H-NMR and real time IR. Evaporation and side reactions, e.g. alkene reactions, are competing factors to the transesterification reaction. The study showed that fatty acid structure, reaction time, and temperature affect the transesterification conversion, degree of side reactions, and choice of catalyst. A pigmented fully formulated polyester/melamine formulation with a reactive diluent was cured at full scale in an industrial coil-coating production facility. Evaluation of the final film properties showed that the coating fulfills the specification of conventional polyester/melamine coil-coating systems. / QC 20100817

A pulsed Nd:YAG laser is used to study laser spark ignition of methane counter-flow diffusion flames with the use of helium and argon as diluents to achieve a wide range of variations in transport properties. The global strain rate and Damkohler number on successful ignition were investigated for the effects of Lewis number and transport properties, which are dependent on the diluent type and dilution level. A high-speed camera is used to record the ignition events and a software is used for pre-ignition flow field and mixing calculations. It is found that the role of effective Lewis number on the critical global strain rate, beyond which ignition is not possible, is qualitatively similar that on the extinction strain rate. With the same level of dilution, the inert diluent with smaller Lewis number yields larger critical global strain rate. The critical Damkohler number below which no ignition is possible is found to be within approximately 20% for all the fuel-inert gas mixtures studied. When successful ignition takes place, the ignition time increases as the level of dilution of argon is increased. The ignition time decreases with increasing level of helium dilution due to decreases in thermal diffusion time, which causes rapid cooling of the flammable layer during the ignition process. However, the critical strain for ignition with helium dilution rapidly decreases as the dilution level is increased. The experimental results show that with the increase of strain rate the time to steady flame decreases, and that with the increase of dilution level time for the flame to become steady increases. For the same level of dilution, the time for steady flame is observed to be longer for He-diluted flames than for Ar-diluted flames due to its thermal diffusivity being larger than that of Ar.

Made available in DSpace on 2014-08-20T13:32:51Z (GMT). No. of bitstreams: 1 dissertacao_guilherme_van_der_laan.pdf: 723829 bytes, checksum: 399e8e1ec5f5ec9b7f77f1ffa1d0af80 (MD5) Previous issue date: 2007-11-30 / Adding extenders to poultry semen is currently used in artificial insemination programs to optimize the management of genetically superior males. Fresh semen fertility usually declines after 1 hour of collection, raising the need to use diluents and low temperatures to store semen for longer periods. Low density lipoprotein (LDL), extracted from the egg yolk, is used as a component of various mammalian semen diluents, however its application on poultry semen has not been evaluated. Regarding cryopreservation, different methodologies have been developed during the past years. One alternative is to use dimethylacetamide (DMA) as a cryoprotectant. The best results with DMA are obtained when semen is subjected to ultra-fast freezing, in pellets, and to a fast thawing at 60ºC. The objective of this work was to establish protocols to preserve rooster sperm, focusing on the use of LDL as a component of the refrigeration diluent, and on DMA as a internal cryoprotectant for freezing. To reach these objectives, the effect of adding different levels of LDL liposomes to the cooling diluent, upon the quality characteristics of semen refrigerated at 5 °C, was evaluated. The quality of semen frozen with DMA, packed in straws or pellets, and thawed in three different temperatures was also evaluated. The results obtained allow to conclude that: adding 6% of LDL liposomes to the cooling diluent preserves the general sperm quality, suggesting that improvements on fertility could be obtained if a limit in lipoprotein supplementation is imposed; body temperature (40°C) is most suitable for thawing sperm frozem with DMA; and packing sperm in straws is more efficient than packing in pellets. This last observation is of great value, since storing semen in straws is more appropriate due to sanitary reasons, and more convenient for ejaculates identification, especially for field application of genetic banks. / A adição de diluentes ao sêmen de aves é uma prática rotineiramente empregada em programas de inseminação artificial para melhorar o manejo de machos geneticamente superiores. A fertilidade do sêmen fresco normalmente decai 1 hora após a coleta, por isso a necessidade do uso de diluentes e temperaturas hipotérmicas para o armazenamento do sêmen por períodos mais prolongados. A Lipoproteína de Baixa Densidade (LDL), extraída da gema de ovo, tem sido utilizada na composição de diversos diluentes de sêmen para mamíferos, porém, ainda não tinha sido avaliada a sua aplicação em diluentes de resfriamento para sêmen de aves. Em relação ao congelamento, diversos métodos foram desenvolvidos ao longo dos anos. Uma das alternativas é o uso da Dimetilacetamida (DMA) como crioprotetor. Os melhores resultados obtidos com DMA ocorrem quando o sêmen é submetido ao congelamento ultra-rápido na forma de pellets e a um rápido descongelamento à 60ºC. O objetivo deste trabalho foi o estabelecimento de protocolos de preservação de sêmen de galos, enfocando o uso de Lipoproteínas de Baixa Densidade (LDL) como um componente do diluente para resfriamento, e a Dimetilacetamida (DMA) como crioprotetor interno para o congelamento. Para isto, foi verificado o efeito da adição de diferentes níveis de lipossomas de LDL na composição do diluente de resfriamento, sobre as características de qualidade do sêmen resfriado à 5 °C. Também foi avaliada a qualidade do sêmen congelado utilizando DMA como crioprotetor, envasado em palhetas ou pellets, e descongelados em três diferentes temperaturas. Os resultados obtidos nestes estudos nos permitiram concluir que: a adição de lipossomas de LDL ao diluente de resfriamento mantém a qualidade geral dos espermatozóides quando adicionado na proporção de 6%; sugerindo que melhorias na fertilidade podem ser obtidas desde que seja respeitado um limite de adição desta lipoproteína ao diluente; a temperatura corporal (40°C) foi a mais apropriada para descongelamento de sêmen criopreservado com DMA; e ainda, o envase em palhetas é mais eficiente em relação ao pellet. Esta última observação é de grande valor, visto que o armazenamento do sêmen em palhetas é mais adequado por razões sanitárias, e mais conveniente para a identificação dos ejaculados, especialmente para a aplicação a campo de bancos genéticos.