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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Efeito do óleo de linhaça no desempenho, características de carcaça e qualidade de carne de frangos de corte

Almeida, Ana Paula da Silva [UNESP] 20 August 2007 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:27:19Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-08-20Bitstream added on 2014-06-13T18:55:55Z : No. of bitstreams: 1 almeida_aps_me_araca.pdf: 933088 bytes, checksum: 66f57629124cdebcfa4b653eca08077f (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O objetivo deste trabalho foi avaliar a incorporação de ácidos graxos poliinsaturados (PUFA) na carne de frango com a utilização de ração enriquecida com óleo de soja e óleo de linhaça, associados a diferentes níveis de vitamina E. A inclusão de óleo de linhaça, substituindo o óleo de soja em diferentes proporções, e de vitamina E até o nível de 400 mg/kg de ração, não interferiu, de forma geral, nas características de desempenho e de composição de carcaça de frangos de corte da linhagem Cobb. O sexo das aves, por outro lado, influenciou significativamente essas características. Os machos apresentaram, em termos gerais, melhor desempenho produtivo que as fêmeas, com maior consumo de ração e ganho de peso e melhor conversão alimentar. As fêmeas apresentaram maior porcentagem de peito e menor porcentagem de coxa e sobrecoxa que os machos. Com relação às características da carne, o sexo e a fonte de ácidos graxos poliinsaturados e os níveis de vitamina E da ração não apresentaram influência no teor de lipídeos totais, na textura e na perda de peso no cozimento. A adição de linhaça na dieta também não modificou o padrão de ácidos graxos, nem o teor de colesterol da carne. Os machos apresentaram maior proporção de PUFA que as fêmeas nos dois cortes analisados. Com relação ao teor de colesterol total, as amostras de peito provenientes dos machos apresentaram médias mais elevadas em relação às das fêmeas. A inclusão de 200mg/kg de vitamina E na ração foram suficientes para impedir a rancidez oxidativa nas amostras de coxa e sobrecoxa com pele, estocadas a -25ºC por 45 dias. / The aim of this work was to evaluate the incorporation of polyunsaturated fatty acids (PUFA) in broilers meat using soy and linseed oil enriched rations and different levels of vitamin E. The inclusion of different percentages of linseed oil instead of soy oil and vitamin E until 400 mg/kg in the diets did not interfere in overall performance or composition characteristics of Cobb broilers carcasses. On the other hand, broilers` sexes influenced these characteristics. Male broilers consumed more ration, had higher weight gains and better feed conversions than female broilers. Female broilers had higher breast percentages and lower leg percentages than male broilers. Sex, source of polyunsaturated fatty acids and vitamin E level did not influence total fat content of meat, texture and loose of weight after cooking. The inclusion of linseed oil in the diet did not cause any modification on meat fatty acids composition or total cholesterol content. Male broilers breast and leg samples had higher PUFA content than female broilers. Male broilers had higher cholesterol contents than female broilers in breast cuts. Vitamin E at 200 mg/kg was enough to prevent oxidative rancidity in leg samples frozen at -25ºC for 45 days.
32

Efeito do óleo de linhaça no desempenho, características de carcaça e qualidade de carne de frangos de corte /

Almeida, Ana Paula da Silva. January 2007 (has links)
Orientador: Marcos Franke Pinto / Banca: Manoel Garcia Neto / Banca: Massami Shimokomaki / Resumo: O objetivo deste trabalho foi avaliar a incorporação de ácidos graxos poliinsaturados (PUFA) na carne de frango com a utilização de ração enriquecida com óleo de soja e óleo de linhaça, associados a diferentes níveis de vitamina E. A inclusão de óleo de linhaça, substituindo o óleo de soja em diferentes proporções, e de vitamina E até o nível de 400 mg/kg de ração, não interferiu, de forma geral, nas características de desempenho e de composição de carcaça de frangos de corte da linhagem Cobb. O sexo das aves, por outro lado, influenciou significativamente essas características. Os machos apresentaram, em termos gerais, melhor desempenho produtivo que as fêmeas, com maior consumo de ração e ganho de peso e melhor conversão alimentar. As fêmeas apresentaram maior porcentagem de peito e menor porcentagem de coxa e sobrecoxa que os machos. Com relação às características da carne, o sexo e a fonte de ácidos graxos poliinsaturados e os níveis de vitamina E da ração não apresentaram influência no teor de lipídeos totais, na textura e na perda de peso no cozimento. A adição de linhaça na dieta também não modificou o padrão de ácidos graxos, nem o teor de colesterol da carne. Os machos apresentaram maior proporção de PUFA que as fêmeas nos dois cortes analisados. Com relação ao teor de colesterol total, as amostras de peito provenientes dos machos apresentaram médias mais elevadas em relação às das fêmeas. A inclusão de 200mg/kg de vitamina E na ração foram suficientes para impedir a rancidez oxidativa nas amostras de coxa e sobrecoxa com pele, estocadas a -25ºC por 45 dias. / Abstract: The aim of this work was to evaluate the incorporation of polyunsaturated fatty acids (PUFA) in broilers meat using soy and linseed oil enriched rations and different levels of vitamin E. The inclusion of different percentages of linseed oil instead of soy oil and vitamin E until 400 mg/kg in the diets did not interfere in overall performance or composition characteristics of Cobb broilers carcasses. On the other hand, broilers' sexes influenced these characteristics. Male broilers consumed more ration, had higher weight gains and better feed conversions than female broilers. Female broilers had higher breast percentages and lower leg percentages than male broilers. Sex, source of polyunsaturated fatty acids and vitamin E level did not influence total fat content of meat, texture and loose of weight after cooking. The inclusion of linseed oil in the diet did not cause any modification on meat fatty acids composition or total cholesterol content. Male broilers breast and leg samples had higher PUFA content than female broilers. Male broilers had higher cholesterol contents than female broilers in breast cuts. Vitamin E at 200 mg/kg was enough to prevent oxidative rancidity in leg samples frozen at -25ºC for 45 days. / Mestre
33

Síntese e caracterização de biolubrificante derivado do óleo de linhaça / Synthesis and characterization of biolubrificant derived from linseed oil

Alves, Roger Pereira 03 February 2015 (has links)
Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2015-04-16T14:44:01Z No. of bitstreams: 2 Dissertação - Roger Pereira Alves - 2015.pdf: 1984653 bytes, checksum: acab08cd2cf2271fa365158234c85c93 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2015-04-16T14:52:13Z (GMT) No. of bitstreams: 2 Dissertação - Roger Pereira Alves - 2015.pdf: 1984653 bytes, checksum: acab08cd2cf2271fa365158234c85c93 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-04-16T14:52:13Z (GMT). No. of bitstreams: 2 Dissertação - Roger Pereira Alves - 2015.pdf: 1984653 bytes, checksum: acab08cd2cf2271fa365158234c85c93 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2015-02-03 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / It has grown in recent year’s concerns about the environment preservation and extension use of renewable products and its low toxicity. Thus, it is necessary to replace the use of petroleum and its derivatives by bioproduct. The petroleum derivatives can pollute soil and water further the air. As an example, only a quarter of fossil lubricants manufactured in the world are recycled, causing a huge range of toxic waste to the environment. So the aim of this work is to synthesize a biolubricant less aggressive to the environment, certainly do not contain synthetic additives, viscosity modifiers, corrosion inhibitors and high concentration of heavy metals, as well as increasing the rate of manufacture process then they cause irreparable damage for the diverse ecosystems. The biolubricant was synthetized via alkylation, etherification and esterification reactions of linseed oil. The biolubricant obtained showed excellent physicochemical properties such as high flash point, viscosity, lubricity and thermal stability, it also showed low acid value, volatility, pour point and cloud point, not being corrosive to copper, with good oxidative stability, and compete in the global lubricants market. / Nos últimos anos tem crescido as preocupações sobre a preservação do meio ambiente e a ampliação do uso de produtos renováveis e de baixa toxicidade. Portanto, tem-se procurado substituir o uso de petróleo e seus derivados por bioprodutos. Além da poluição atmosférica, os derivados de petróleo podem contaminar o solo e a água. Como exemplo cita-se que apenas um quarto dos lubrificantes fósseis produzidos no mundo é reciclado, gerando uma quantidade gigantesca de resíduos tóxicos à natureza. Assim, este trabalho foi desenvolvido com o objetivo de sintetizar um biolubrificante renovável, menos agressivo ao meio ambiente, que não contenha aditivos sintéticos, modificadores de viscosidade, inibidores de corrosão e elevada quantidade de metais pesados, visando diminuir custos de produção e minimizar impactos para os diferentes ecossistemas. O biolubrificante foi sintetizado via reação de alquilação, eterificação e esterificação do óleo de linhaça. O biolubrificante obtido apresentou excelentes propriedades físico-químicas como elevado ponto de fulgor, índice de viscosidade, lubricidade e estabilidade térmica, além de apresentar baixo índice de acidez, volatilidade, ponto de fluidez e névoa, não ser corrosivo ao cobre e apresentar adequada estabilidade oxidativa, demonstrando elevada capacidade de empregabilidade no mercado de lubrificantes mundiais.
34

Fonctionnalisation et photopolymérisation de l'huile de lin en vue de l'élaboration de nouveaux matériaux sans émissions de composés organiques volatiles (COV) / Functionnalisation and photopolymérization of linseed oil for elaboration of new materials without emission of volatils organics compounds (COV)

Zovi, Ornella 27 November 2009 (has links)
De nos jours, il est nécessaire de trouver des substituts aux produits dérivés du pétrole car ces derniers ne sont pas renouvelables. C’est donc dans ce but que nous avons envisagé d’élaborer des matériaux constitués principalement d’huile de lin. Ces matériaux ont été élaborés en trois étapes au moyen d’un procédé propre et simple. La première étape est une polymérisation thermique (standolisation), suivie ou précédée d’une étape de modification chimique, tout d’abord par l’anhydride maléique puis par le 2-hydroxyéthyl-méthacrylate (HEMA) qui permet d’introduire des groupements photoréticulables au sein des chaînes de triglycérides. La dernière étape consiste à photopolymériser les huiles modifiées. Nous avons fait varier les taux de standolisation et de modification, puis nous avons déterminé les propriétés physico-chimiques des différents matériaux. La température de transition mécanique de ces matériaux est toujours inférieure à -5 °C et leur flexibilité est d’autant plus importante que le taux de modification est faible. La stabilité thermique ainsi que la biodégradabilité des matériaux ont aussi été étudiées. / The use of renewable sources such as vegetable oils in the elaboration of various industrial materials has been recently revitalized because of the environmental concerns. This is in this context that the elaboration of new materials mainly based on linseed oil was envisaged. These new materials were elaborated in three stages, by means of an easy and clear process. The first stage consisted in a thermal or stand reaction, followed or preceded by a chemical modification stage by maleic anhydride. Then, the 2-hydroxyethylmethacrylate (HEMA) was grafted on the anhydride functions to introduce photopolymerizable groups. In the last stage, the photopolymerization of the modified oil was carried out. The influence of stand and modification rates on the ultimate UV-cured materials properties was characterized. All these materials exhibited a mechanic transition temperature lower than –5 °C and their flexibility was all the higher than the modification rate is low. Thermal stability as well as biodegradation of these materials were also determined.
35

Synthèse et caractérisation de systèmes micellaires stimuli-sensibles à partir d’huile de lin / Synthesis and characterisation of stimuli-responsives micellar systems from linseed oil

El Asmar, Arlette 03 November 2017 (has links)
L'intérêt des copolymères amphiphiles se retrouve dans de multiples applications telles que le: supports catalytique, la bio-séparation ou encore la vectorisation de principe actif. L'étude de leu auto-association sous forme micellaire est très étendue notamment via l'utilisation de polymère: intelligents. Cette classe de polymères présente un changement de comportement lors d'un modification de son environnement. Ainsi des polymères pH et thermo-sensibles ont été sélectionnés dans le but d'étudier des systèmes micellaires composés d'un cœur hydrophobe issus de l'huile de lin et d'une couronne hydrophile stimuli-sensible. Cependant, pour chaque application visée, la synthèse de macromolécules de composition et/ou d'architecture complexe possédant de nouvelles propriétés est nécessaire. Afin de contourner les limitations de cette approche, uni alternative reposant sur le mélange physique de copolymères a été étudiée dans le but de moduler les propriétés et combiner deux sensibilités. / Amphiphilic copolymers have attracted a large interest as they find numerous applications in catalyst support, bio-separation devices and drug delivery systems. Their auto-association in aqueous media forming micelles are well-studied, particularly by the use of smart polymers which display a significant physicochemical change in response to modification of their environment. In this work, pH and temperature responsive polymers have been studied for the elaboration of micellar systems composed of a hydrophobic core from linseed oil and hydrophilic stimuli-sensitive coronna. However the common approach is to design one specific macromolecule for one given application, with sometimes complex composition and/or architecture. We aim to investigate a straight-forward pathway towards micellar systems with finely tuned sensitivities by the cooperative self-assembly of two different copolymers to manipulate the physico-chemical behavior of the final mixed system.
36

Modified Alkyds for High Solids Coatings and Adhesives

Salata, Ryan Robert January 2017 (has links)
No description available.
37

Study of Grain Formation in Linseed Oil-Based Paints / Studier av kornbildning i linoljebaserade färger

Almas, Ria Afifah January 2020 (has links)
Studien har klart och tydligt resulterat i att ett antalspecifika resultat rörande betydelsen av olika materialsammansättningars påverkan kornbildningen. Resultaten visar på vilka orsaker som finns för denna kornbildning samt hur färgsammansättningen kan varieras för att minska detta problem. / A study of grain formation in linseed oil-based paint have been conducted. The grains were formed in linseed oil paints with either Yellow1, Yellow 2, Black, or Red as the pigments. There are two types of grain formation which has been observed from the paint samples. (a) The grains which immediately appear in the newly made paint with Yellow 1, Yellow 2, and Red paints (b) while the other type is the grain that developed as the function of storage time in Black linseed oil paint. The results clearly show the cause of the defects.
38

Towards commercialization of self-healing technology in epoxy coating

Ye, Lujie January 2014 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / This work is focused on developing viable self-healing coatings, especially considering the viability of the coating in a commercial context. With this in mind, finding low cost healing agents, with satisfactory healing and mechanical properties as well as adapting the healing system for use in coatings was required. Seven potential healing agents were evaluated and an air-drying triglyceride (linseed oil) was identified as the candidate healing agent. Different encapsulation techniques were evaluated and ureaformaldehyde microcapsules were chosen as the candidate encapsulation technique. Self-healing coatings were fabricated using urea-formaldehyde encapsulated linseed oil. EIS, SEM and TGA technologies were used to evaluate mechanical performance, corrosion resistance, and self-healing performance.
39

Estudo do efeito de autorreparação nos revestimentos aditivados com microcápsulas contendo óleo de linhaça. / Study of the self-healing effect of coatings additivated with microcapsules containing linseed oil.

Baptiste Restrepo, Mónica 24 October 2012 (has links)
O objetivo deste trabalho foi a preparação de um revestimento inteligente com resina epóxi, capaz de autorreparar-se quando o sofre um defeito mecânico. A autorreparação é possibilitada pela presença de microcápsulas, dispersas na resina (revestimento de epóxi sem pigmentos) e que contêm no seu núcleo o agente de autorreparação, o óleo de linhaça. Estas cápsulas foram preparadas por uma emulsão de óleo de linhaça em água para formar micelas e sobre estas uma parede ou casca exterior de poliuréia-formaldeído. Para a avaliação da resistência à corrosão e do efeito de autorreparação do revestimento, chapas de aço carbono foram revestidas e avaliadas pela técnica de espectroscopia de impedância eletroquímica (EIE) em 0.1molL-1 1 NaCl e também foram avaliadas pelo teste acelerado de corrosão em câmara de névoa salina (SSC). Após a cura do revestimento aditivado com as microcápsulas, aplicado sobre placas de aço carbono, as medidas eletroquímicas de impedância foram realizadas em corpos de prova com um defeito mecânico provocado de forma controlada e reprodutível. Uma célula de três eletrodos foi utilizada. Estas medidas foram efetuadas após 0h, 24h e 48h da execução da incisão ou defeito mecânico. Para comparação, as mesmas medidas foram realizadas com as placas pintadas com o revestimento não-aditivado, com a mesma espessura total de 120 m. Os resultados mostraram que as cápsulas foram quebradas e se liberou o óleo de linhaça, reparando a área da incisão o defeito após pelo menos 24 horas de exposição natural ao ar ambiente. Verificou-se que para as placas revestidas sem defeito, os valores de | Z | mantiveram-se elevados. No entanto, o revestimento sem as microcápsulas, após 24 horas, mostrou uma diminuição considerável no valor de módulo de impedância, |Z|. Assim, usando a técnica de EIE foi possível avaliar quantitativamente o mecanismo de autorreparação do revestimento aditivado com microcápsulas que contêm óleo de linhaça. Os ensaios acelerados de corrosão (SSC) mostraram resultados em estreita concordância com os obtidos por EIE. / The aim of this work was the preparation of a smart coating with epoxy resin which is able to repair itself (self-healing effect) after suffering a mechanical defect. Self-healing is possible due to the presence of microcapsules, dispersed in the resin (clear type epoxy coating) and contain in their core the self-healing agent, the linseed oil. These capsules were prepared in an emulsion of linseed oil in water to form micelles and an outer skin or wall of poly(urea-formaldehyde) was formed. For the corrosion resistance and the self-healing effect evaluation of the coating, carbon steel plates were coated and tested by electrochemical impedance spectroscopy technique (EIS) in 0.1molL-1 NaCl solution and by accelerated corrosion test in salt spray chamber (SSC). After curing of the capsules additivated epoxy based clear coating applied on carbon steel plates, electrochemical impedance measurements were performed on plates with a controlled and reproducible mechanical defect. A three-electrode electrochemical cell was used. These measurements were performed after 0h, 24h and 48h of making the incision or mechanical defect. For comparison, the same measurements were performed with the plates painted with a non- capsules additivated clear coating of the same total thickness of 120 m. The results showed that the capsules were broken and released the linseed oil, which indeed have repaired the incision area after at least 24 hours of natural air aging. It was found that for the plates coated without a defect, the values of impedance modulus, |Z|, remained high. However, the coating without the capsules after 24 hours, showed a considerable decrease in |Z|. So, using EIS it was possible to quantitatively assess the mechanism of self-healing of the additivated coating using microcapsules containing linseed oil. The SSC accelerated corrosion tests showed results in close agreement with those obtained by EIS.
40

Leite obtido de vacas alimentadas com fontes de ω-3 e ω-6 e utilizado na dieta de fêmeas Sus scrofa domesticus como modelo para aplicabilidade em humanos / Milk obtained from cows fed ω-3 and ω-6 sources and used in the diet of Sus scrofa domesticus as a model for applicability in humans

Reis, Leriana Garcia 22 February 2019 (has links)
O objetivo deste estudo foi avaliar os efeitos do ômega-3 (ω-3) e do ômega-6 (ω-6) do leite e sua importância na nutrição e saúde humana, sobre as características reprodutivas e produtivas, sobre o hemograma, leucograma e perfil de ácidos graxos (AG) do sangue das matrizes e dos leitões, visando a relação ideal de 1:1 a 5:1 (ω-6/ ω-3). O trabalho foi realizado com 30 matrizes, Large White x Landrace, divididas nos tratamentos controle (TC), leite enriquecido naturalmente com ω-3 (TW3) e leite enriquecido naturalmente com ω-6 (TW6), que receberam esta suplementação desde 34 dias de idade até o desmame dos seus leitões. Foi avaliado o desempenho das matrizes e dos leitões, e colhidas amostras de sangue, colostro e leite, para análises laboratoriais. Os resultados mostraram uma melhora no desempenho das matrizes, associado à fase de desenvolvimento em que se encontravam. Dos 34 aos 190 dias, a concentração absoluta de leucócitos foi maior (P=0,049) para TW3 e TW6, mostrando uma alteração no sistema imune das matrizes. No 1º dia de lactação (D1L) houve uma redução (P<0,05) de ureia e VLDL e aumento (P<0,05) de proteína total e LDL para TC. Para as matrizes de 34 a 190 dias de idade e no D1L, o perfil de AG foi alterado (P<0,05) e para os leitões aos 0 e 14 dias de idade, houve maior (P=0,01) concentração de EPA e menor (P=0,045) proporção de AA/EPA para TW3. Os leitões do TW3 e TW6 apresentaram maior peso médio (P=0,004) em relação a TC, pela possível alteração da razão ω-6/ω-3 no organismo, que ocorreu por meio da suplementação das mães. A conclusão do presente estudo é que o fornecimento do leite enriquecido com uma melhor razão ω-6/ω-3, pode induzir alterações metabólicas, com base nos parâmetros sanguíneos analisados, assim como na produtividade dos leitões, afetando seu peso médio. / The objective of this study was to evaluate the effects of omega-3 (ω-3) and omega-6 (ω-6) on milk and its importance in nutrition and human health. the reproductive and productive characteristics, on the hemogram, leukogram and fatty acid profile of the blood of the dams and piglets, aiming at the ideal ratio of 1: 1 to 5: 1 (ω-6 / ω-3). The work was performed with 30 matrices, Large White x Landrace, divided in control treatments (TC), milk enriched naturally with ω-3 (TW3) and milk enriched naturally with ω-6 (TW6), which received this supplementation from 34 days to the weaning of their piglets. The performance of the dams and piglets was evaluated, and samples of blood, colostrum and milk were collected for laboratory analysis. The results showed an improvement in the performance of the matrices, associated to the development phase in which they were. From 34 to 190 days, the absolute leukocyte concentration was higher (P = 0.049) for TW3 and TW6, showing a change in the immune system of the matrices. On the 1st day of lactation (D1L) there was a reduction (P <0.05) of urea and VLDL and increase (P <0.05) of total protein and LDL for CT. For the matings of 34 to 190 days of age and in D1L, the fatty acid profile was altered (P <0.05) and for the piglets at 0 and 14 days of age, there was a higher (P = 0.01) concentration of EPA and lower (P = 0.045) ratio of AA / EPA to TW3. The TW3 and TW6 piglets had a higher mean weight (P = 0.004) compared to CT, due to the possible alteration of the ω-6 / ω-3 ratio in the organism, which occurred through the mothers\' supplementation. The conclusion of the present study is that the supply of enriched milk with a better ω-6 / ω-3 ratio may induce metabolic alterations, based on the blood parameters analyzed, as well as the piglet productivity, affecting its average weight.

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