• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 11
  • 5
  • 5
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • Tagged with
  • 25
  • 25
  • 5
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 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.
11

Proteomics study of the effects of fish oil and corn oil enriched dieton membranous nephritis

Ye, Yisha., 葉伊莎. January 2008 (has links)
published_or_final_version / Biological Sciences / Master / Master of Philosophy
12

Summarizing FLARE assay images in colon carcinogenesis

Leyk Williams, Malgorzata 12 April 2006 (has links)
Intestinal tract cancer is one of the more common cancers in the United States. While in some individuals a genetic component causes the cancer, the rate of cancer in the remainder of the population is believed to be affected by diet. Since cancer usually develops slowly, the amount of oxidative damage to DNA can be used as a cancer biomarker. This dissertation examines effective ways of analyzing FLARE assay data, which quantifies oxidative damage. The statistical methods will be implemented on data from a FLARE assay experiment, which examines cells from the duodenum and the colon to see if there is a difference in the risk of cancer due to corn or fish oil diets. Treatments of the oxidizing agent dextran sodium sulfate (DSS), DSS with a recovery period, as well as a control will also be used. Previous methods presented in the literature examined the FLARE data by summarizing the DNA damage of each cell with a single number, such as the relative tail moment (RTM). Variable skewness is proposed as an alternative measure, and shown to be as effective as the RTM in detecting diet and treatment differences in the standard analysis. The RTM and skewness data is then analyzed using a hierarchical model, with both the skewness and RTM showing diet/treatment differences. Simulated data for this model is also considered, and shows that a Bayes Factor (BF) for higher dimensional models does not follow guidelines presented by Kass and Raftery (1995). It is hypothesized that more information is obtained by describing the DNA damage functions, instead of summarizing them with a single number. From each function, seven points are picked. First, they are modeled independently, and only diet effects are found. However, when the correlation between points at the cell and rat level is modeled, much stronger diet and treatment differences are shown both in the colon and the duodenum than for any of the previous methods. These results are also easier to interpret and represent graphically, showing that the latter is an effective method of analyzing the FLARE data.
13

Effect of corn fibre oil and its constituents on cholesterol metabolism and intestinal sterol transporter gene expression in hamsters

Jain, Deepak M. January 2006 (has links)
The cholesterol-lowering effect of corn fiber oil, obtained from the seed coats of corn kernels, has been reported previously. Corn fiber oil contains phytosteryl fatty acyl esters, ferulate phytostanyl esters, and free phytosterols. To date, however, no studies have examined the cholesterol-lowering efficacy of ferulate phytostanyl esters. Moreover, although plant stanols and sterols have been established as cholesterol-lowering agents over the past five decades, their exact mechanisms of action are not clearly understood. One of the possible mechanism is that plant sterols/stanols disrupts the normal sub-cellular cholesterol absorption by down-regulation of the influx sterol transporters such as the Niemann pick C1 like 1(NPC1L1) protein and/or up-regulation of efflux sterol transporters such as the ATP binding cassette (ABC) G5 and ABCG8 protein. Hence, the objectives of this thesis were to assess the efficacy of corn fiber oil, ferulate phytostanyl esters and their parent compounds including sitostanol and ferulic acid, on plasma cholesterol levels. Further, objectives were to investigate their impact on parameters of cholesterol kinetics and gene expression of sterol transporters to obtain insight into their role in genetic control of regulation of cholesterol flux. Results of this experiment demonstrate that the hypocholesterolemic effect of corn fiber oil is mostly due to sitostanol, while esterification of ferulic acid and sitostanol yields no apparent synergistic cholesterol lowering effect. Present data exhibited a cholesterol absorption lowering effect of corn fiber oil and sitostanol and suggest that this effect may be due to up-regulation of intestinal enterocyte efflux sterol transporters such as ABCG5 and ABCG8.
14

A study of nutritional deficiencies of corn-soybean oil meal rations for swine and rats

Cunha, Tony J., January 1944 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1944. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographies: leaves 22-24, 70-73.
15

Otimização das variáveis de processo da transesterificação do óleo de soja e milho = produção de biodiesel em uma coluna de pratos perfurados / Optimization of the process variables of the transesterification of soybean oil and corn oil : biodiesel production in a sieve tray column

Dantas, Tarcisio Soares Siqueira, 1980- 19 August 2018 (has links)
Orientador: Maria Regina Wolf Maciel / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-19T03:53:54Z (GMT). No. of bitstreams: 1 Dantas_TarcisioSoaresSiqueira_M.pdf: 911186 bytes, checksum: 5dd1da3ddee6346c9e4cbb05214e5f7d (MD5) Previous issue date: 2011 / Resumo: A transesterificação com etanol é um tópico de pesquisa bastante atual devido à possibilidade de produzir um combustível utilizando apenas fontes renováveis. Este trabalho apresenta a produção de biodiesel em uma coluna de destilação reativa de pratos perfurados e a otimização de suas variáveis de processo foi realizada utilizando ferramentas estatísticas. A destilação reativa é a implementação simultânea de reação e separação em uma mesma unidade de processo e, através dela, é possível atingir conversões altas rapidamente e com menores gastos energéticos. O óleo de soja e o óleo de milho refinados foram utilizados como matérias-primas na reação de transesterificação com o etanol e o catalisador (hidróxido de sódio). Os resultados finais de conversão em éster foram comparados com resultados obtidos por outros pesquisadores em uma coluna de destilação reativa empacotada. A conversão ótima de éster foi de 99,84% em peso com 6 minutos de reação e um modelo, com significância estatística, da conversão em éster em função da razão molar álcool:óleo e da concentração de catalisador foi obtido / Abstract: Transesterification with ethanol is very up-to-date due to the possibility of producing a fuel solely from renewable sources. This work presents the biodiesel production with a reactive distillation sieve tray column and the optimization of the process variables using statistical tools was carried out. Reactive distillation is the simultaneous implementation of reaction and separation within a single process unit and it is able to achieve very fast conversions and high yields with relatively low energy requirements. Refined soybean oil and corn oil where used as feedstocks in the transesterification with the ethanol and the sodium hydroxide catalyst. The results on the final ester conversion where compared to results obtained with a packed reactive distillation column by other researchers. The optimum ester (biodiesel) conversion was 99.84 wt. % after 6 minutes of reaction and a model, with statistical significance, of the ester conversion as a function of molar ratio and catalyst concentration was obtained / Mestrado / Desenvolvimento de Processos Químicos / Mestre em Engenharia Química
16

Effect of corn fibre oil and its constituents on cholesterol metabolism and intestinal sterol transporter gene expression in hamsters

Jain, Deepak M. January 2006 (has links)
No description available.
17

Production of biodiesel from vegetable oils

Ramos, Boris January 2012 (has links)
The production of biodiesel using vegetables oils is studied. Palm oil and its use for production of biodiesel have been focused. Palm tree is very productive and one of the most profitable for biodiesel production. Among the oilseed crops palm tree produce more oil per hectare. Palm oil has a good availability and a competitive price. The production of palm oil at the industrial plantation level has caused environmental damage. The Roundtable on Sustainable Palm Oil has established principles and criteria in order to certify a sustainable cultivation of the palm oil. The experimental work involves the production of biodiesel using corn oil. Ethanol and methanol are used as alcohols. Sodium and potassium hydroxides are selected as catalyst. The ratio alcohol to oil is the most important parameter in the production of biodiesel.  An excess of alcohol is required to drive the reaction to the right.  In the experiments with ethanol the yield of biodiesel increased with the ratio ethanol/oil achieving the highest yield at a molar ratio ethanol/oil: 7.78. In the experiments with methanol, using 0.9 g NaOH and 1 hour reaction time the highest yield was obtained with  a molar ratio methanol:oil = 9. Using KOH as catalyst and 2 hour reaction time a very good yield is already obtained with a molar ratio methanol:oil = 4.5 The amount of catalyst is another studied parameter. In the experiments with ethanol, the amount of 0.8 mg NaOH and 1.2 mg KOH for 200 ml corn oil (0.22 mol) is enough in order to obtain a good yield. An increase of the amount of catalyst does not produce an increase of the yield of biodiesel. In experiments with methanol, using the lowest tested amount catalyst (0.85 g KOH and 0.23 g NaOH) a good yield of biodiesel is obtained. The effects of the reaction time, rate of mixing and the reaction temperature were studied in the experiments with methanol. The yield of biodiesel increased when the reaction time is increased from 1 to 2 hours. The yield of produced biodiesel increased from 90% to 94% when the rate of mixing was increased from 500 to 1500 rpm. Often the transesterification is carried out at a temperature near the boiling point of alcohol. The highest yield was obtained at 60 oC with KOH and at 55 oC using NaOH but already at 40 oC a good yield was obtained (89%).
18

Reestruturação da gordura do leite por mistura e interesterificação com óleo de milho. / Restructuring milkfat through blending and interesterification with corn oil.

Rodrigues, Juliana Neves 27 June 2002 (has links)
O consumidor está se tornando mais consciente da relação entre alimentação e doenças, o que tem impulsionado as pesquisas na área de alimentos funcionais e seus efeitos no organismo. As gorduras são um importante componente da dieta humana, porém a dieta ocidental apresenta um desequilíbrio quanto ao tipo de gordura consumida. As gorduras saturadas são consumidas em grande quantidade, o que pode provocar doenças cardiovasculares, que atualmente constituem a principal causa de morte no Brasil. O consumo de manteiga, cujo componente mais abundante é a gordura do leite, vem caindo muito pois a gordura do leite é altamente saturada, mas tem sabor muito agradável e é muito apreciada pelo consumidor. Além disso, a margarina surgiu como um substituto que apresenta melhor espalhabilidade à temperatura de refrigeração. Assim, os objetivos do trabalho são: desenvolver uma base gordurosa que utilize a gordura do leite, mantenha as qualidades inerentes da manteiga, mas que apresente maior espalhabilidade e contenha maiores teores de ácidos graxos w-6. Para isso, foi adicionado à gordura do leite o óleo de milho, que apresenta alto teor de ácidos graxos poliinsaturados, e as misturas foram submetidas à interesterificação química. Foram avaliadas as interações que ocorreram nestas misturas binárias antes e depois da reação. As misturas foram analisadas quanto a acidez, composição em ácidos graxos e triacilgliceróis, índices de iodo e saponificação, ponto de amolecimento, consistência, conteúdo de gordura sólida, curvas de solidificação, cinética de cristalização, estrutura cristalina e dimensão fractal. Foi utilizado como catalisador da reação química o metóxido de sódio, em proporção de 0,5%. A reação foi realizada à temperatura de 65 a 70ºC por uma hora. Foram obtidos lipídeos estruturados contendo teores de até 22% de ácidos graxos poliinsaturados w-6 pela adição de até 40% óleo de milho à gordura do leite, que originalmente possuía apenas cerca de 2%. Os coeficientes obtidos para as propriedades de consistência e conteúdo de gordura sólida relativos às interações entre as gorduras foram sempre negativos, demonstrando efeito antagônico, característico de interações monotéticas entre as gorduras. A mistura contendo 70% de gordura do leite e 30% de óleo de milho apresentou plasticidade própria de um spread, propriedade que foi melhorada com a reação de interesterificação. A adição de óleo de milho não provocou mudanças substanciais na estrutura da rede cristalina da gordura do leite, apenas diminuiu a quantidade de gordura cristalizada. / Consumer is becoming increasingly aware of the dependence of human health on proper nutrition, what has impelled researches in the field of functional foods and its effects on human metabolism. Fats are an important component of the diet, but ocidental diet can not be considered balanced as for the type of fat consumed. Saturated fats are consumed in great amounts, what can lead to cardiovascular diseases, the main death cause in Brazil. The consumption of butter, which principal component is milkfat, has been declining due to milkfat’s high degree of saturation, although it has a very pleasant flavor and is very appreciated by consumer. Besides, margarine appeared as a substitute that presents more spreadability at refrigeration temperature. The objective of this study was to develop a blend based on milkfat, that keeps the inherent qualities of butter but presents better spreadability and higher contents of w-6 fatty acids. Milkfat was blended with corn oil, a vegetable oil that contains high levels of polyunsaturated fatty acids, and the blends were submitted to chemical interesterification. The interactions between the two fats before and after interesterification were evaluated. The blends were analyzed as for free fatty acids, fatty acid and triacylglycerol composition, iodine and saponification values, softening point, consistency, solid fat content, crystallization kinetics, crystalline structure, and fractal dimension. Sodium methoxide (0,5% w/w) was used as catalyst for chemical interesterification. The reaction was undertaken at 65-70ºC for one hour. Structured lipids containing up to 22% of polyunsaturated fatty acids were obtained with the addition of up to 40% of corn oil to milkfat, which originally had only about 2%. The coefficients related to the interactions between the two fats were always negative for consistency and solid fat content, revealing an antagonistic effect, characteristic of monotectic interactions between fats. The blend containing 70% of milkfat and 30% of corn oil presented good plasticity for a spread. This property was improved by interesterification. The addition of corn oil did not cause substantial changes on the crystalline structure of milkfat, but only decreased the content of crystallized fat.
19

Reestruturação da gordura do leite por mistura e interesterificação com óleo de milho. / Restructuring milkfat through blending and interesterification with corn oil.

Juliana Neves Rodrigues 27 June 2002 (has links)
O consumidor está se tornando mais consciente da relação entre alimentação e doenças, o que tem impulsionado as pesquisas na área de alimentos funcionais e seus efeitos no organismo. As gorduras são um importante componente da dieta humana, porém a dieta ocidental apresenta um desequilíbrio quanto ao tipo de gordura consumida. As gorduras saturadas são consumidas em grande quantidade, o que pode provocar doenças cardiovasculares, que atualmente constituem a principal causa de morte no Brasil. O consumo de manteiga, cujo componente mais abundante é a gordura do leite, vem caindo muito pois a gordura do leite é altamente saturada, mas tem sabor muito agradável e é muito apreciada pelo consumidor. Além disso, a margarina surgiu como um substituto que apresenta melhor espalhabilidade à temperatura de refrigeração. Assim, os objetivos do trabalho são: desenvolver uma base gordurosa que utilize a gordura do leite, mantenha as qualidades inerentes da manteiga, mas que apresente maior espalhabilidade e contenha maiores teores de ácidos graxos w-6. Para isso, foi adicionado à gordura do leite o óleo de milho, que apresenta alto teor de ácidos graxos poliinsaturados, e as misturas foram submetidas à interesterificação química. Foram avaliadas as interações que ocorreram nestas misturas binárias antes e depois da reação. As misturas foram analisadas quanto a acidez, composição em ácidos graxos e triacilgliceróis, índices de iodo e saponificação, ponto de amolecimento, consistência, conteúdo de gordura sólida, curvas de solidificação, cinética de cristalização, estrutura cristalina e dimensão fractal. Foi utilizado como catalisador da reação química o metóxido de sódio, em proporção de 0,5%. A reação foi realizada à temperatura de 65 a 70ºC por uma hora. Foram obtidos lipídeos estruturados contendo teores de até 22% de ácidos graxos poliinsaturados w-6 pela adição de até 40% óleo de milho à gordura do leite, que originalmente possuía apenas cerca de 2%. Os coeficientes obtidos para as propriedades de consistência e conteúdo de gordura sólida relativos às interações entre as gorduras foram sempre negativos, demonstrando efeito antagônico, característico de interações monotéticas entre as gorduras. A mistura contendo 70% de gordura do leite e 30% de óleo de milho apresentou plasticidade própria de um spread, propriedade que foi melhorada com a reação de interesterificação. A adição de óleo de milho não provocou mudanças substanciais na estrutura da rede cristalina da gordura do leite, apenas diminuiu a quantidade de gordura cristalizada. / Consumer is becoming increasingly aware of the dependence of human health on proper nutrition, what has impelled researches in the field of functional foods and its effects on human metabolism. Fats are an important component of the diet, but ocidental diet can not be considered balanced as for the type of fat consumed. Saturated fats are consumed in great amounts, what can lead to cardiovascular diseases, the main death cause in Brazil. The consumption of butter, which principal component is milkfat, has been declining due to milkfat’s high degree of saturation, although it has a very pleasant flavor and is very appreciated by consumer. Besides, margarine appeared as a substitute that presents more spreadability at refrigeration temperature. The objective of this study was to develop a blend based on milkfat, that keeps the inherent qualities of butter but presents better spreadability and higher contents of w-6 fatty acids. Milkfat was blended with corn oil, a vegetable oil that contains high levels of polyunsaturated fatty acids, and the blends were submitted to chemical interesterification. The interactions between the two fats before and after interesterification were evaluated. The blends were analyzed as for free fatty acids, fatty acid and triacylglycerol composition, iodine and saponification values, softening point, consistency, solid fat content, crystallization kinetics, crystalline structure, and fractal dimension. Sodium methoxide (0,5% w/w) was used as catalyst for chemical interesterification. The reaction was undertaken at 65-70ºC for one hour. Structured lipids containing up to 22% of polyunsaturated fatty acids were obtained with the addition of up to 40% of corn oil to milkfat, which originally had only about 2%. The coefficients related to the interactions between the two fats were always negative for consistency and solid fat content, revealing an antagonistic effect, characteristic of monotectic interactions between fats. The blend containing 70% of milkfat and 30% of corn oil presented good plasticity for a spread. This property was improved by interesterification. The addition of corn oil did not cause substantial changes on the crystalline structure of milkfat, but only decreased the content of crystallized fat.
20

Development of PVT methodology and mounting experimental apparatus / Desenvolvimento de metodologia PVT e montagem de aparato experimental

Filipe Xavier Feitosa 25 February 2013 (has links)
CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior / The aim of this work was to assemble an experimental apparatus PVT skilled labor in obtaining phase equilibria at high pressures and determining efficient methodology. Tests were performed mounting apparatus in order to develop methodology. During these tests, the data bubble point of pure carbon dioxide were determined at temperatures of 25, 26, 27 and 28  C and compared with data obtained for similar equipment, providing average deviation of 0.4 Bar, 0.6% on the extent being of the same order of magnitude compared to similar equipment. For testing systems in which one liquid component is introduced at ambient pressure in the analysis phase equilibrium torque was analyzed ethanol-CO2 at 40  C, and also compared with the literature data. The results obtained in steps preliminary analyzes showed that the system was capable of developing new data phase equilibrium. The study continued with the application development methodology for systems of viscera from fish oil + carbon dioxide oil, fish viscera + carbon dioxide + ethanol, corn oil + carbon dioxide and corn oil + ethanol + carbon dioxide at temperatures of 40, 50, 60, 70, 80, 90 and 110  C for systems without ethanol at temperatures of 40, 60, 80 and 110  C, for others. The phase diagrams obtained for all systems studied were of type IV according to the classification of Von Konynen and Scott, which is similar to that found in literature phase diagrams for systems consisting of triglycerides and carbon dioxide, showing the ability development of new data for the set-apparatus developed methodology. / O objetivo desta dissertaÃÃo foi montar um aparato experimental PVT hÃbil ao trabalho na obtenÃÃo de equilÃbrio de fases em altas pressÃes e a determinaÃÃo de metodologia eficiente. Testes de montagem no aparato foram realizados com o intuito de desenvolver a metodologia. Durantes estes testes, dados do ponto de bolha do diÃxido de carbono puro foram determinados em temperaturas de 25, 26, 27 e 28 ÂC e comparados com dados obtidos para equipamentos similares, fornecendo desvio mÃdio de 0,4 Bar, 0,6 % relativo à medida, sendo da mesma ordem de grandeza em relaÃÃo a equipamentos similares. Para testes de sistemas em que um componente lÃquido à pressÃo ambiente fosse introduzido nas anÃlises de equilÃbrio de fases o binÃrio etanol-CO2 foi analisado a 40 ÂC, e tambÃm comparado com dados da literatura. Os resultados obtidos nas etapas de anÃlises preliminares mostraram que o sistema estava apto a desenvolver novos dados de equilÃbrio de fases. Os estudos prosseguiram com o desenvolvimento da aplicaÃÃo da metodologia para os sistemas de Ãleo de vÃscera de peixe + diÃxido de carbono, Ãleo de vÃscera de peixe + etanol + diÃxido de carbono, Ãleo de milho + diÃxido de carbono e Ãleo de milho + etanol + diÃxido de carbono nas temperaturas de 40, 50, 60, 70, 80, 90 e 110 ÂC para os sistemas sem etanol e nas temperaturas de 40, 60, 80 e 110 ÂC, para os demais. Os diagramas de fases obtidos para todos os sistemas estudados foram do tipo IV de acordo com a classificaÃÃo de Von Konynen e Scott, o que se assemelha ao encontrado na literatura de diagramas de fase para sistemas constituÃdos de triglicerÃdeos e diÃxido de carbono, mostrando a capacidade de desenvolvimento de novos dados para o conjunto metodologia-aparato desenvolvido.

Page generated in 0.0579 seconds