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Obtenção e caracterização de organogéis de óleo de soja preparados com cera de cana-de-açúcar e suas franções / Obtainment and characterization of organogels of soybean oil prepared with sugarcena wax and its fractionsRocha, Julio Cesar Barbosa, 1982- 20 August 2018 (has links)
Orientador: Daniel Barrera Arellano / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-20T11:35:24Z (GMT). No. of bitstreams: 1
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Previous issue date: 2012 / Resumo: Os óleos e gorduras representam um papel nutricional chave na alimentação humana e apresentam importância como estrutura de muitos produtos alimentícios que consumimos, como margarinas, por exemplo. Gorduras sólidas, ricas em ácidos graxos saturados foram, durante muito tempo, utilizadas para obter produtos com as características tecnológicas desejáveis de textura e dureza, sendo substituídas por gorduras ricas em ácidos graxos trans. Com a descoberta dos efeitos negativos dos ácidos graxos trans para a saúde esses materiais foram substituídos por gorduras de alta tecnologia obtidas por processos químicos de interesterificação que novamente se utilizam da presença de ácidos graxos saturados. Alternativas tecnológicas visando à redução dos teores de ácidos graxos saturados se fazem necessárias. Sendo o óleo de soja de baixo custo, elevada disponibilidade e baixo teor de ácidos graxos saturados, ele se mostra adequado ao desenvolvimento de novas gorduras tecnológicas utilizando ceras vegetais como agentes estruturantes, para a obtenção de organogéis. Organogéis são misturas com capacidade de se auto-sustentarem, formadas por uma fase contínua líquida e um agente estruturante, neste caso a cera. A cera de cana- de-açúcar tem seu interesse elevado devido ao alto potencial produtivo brasileiro, aliado à suas características físicas. O objetivo deste trabalho foi avaliar o potencial de formação de organogéis com a cera de cana-de-açúcar e suas frações solúvel e insolúvel em etanol a quente e avaliar o comportamento físico desses organogéis. Os três estruturantes estudados apresentaram capacidade de formar organogéis na condição de cristalização estática a 5°C nas concentrações estudadas (1, 2, 3 e 4% m/m), e apenas a fração insolúvel em etanol a quente incapaz de formar organogéis estáveis sob a condição de cristalização estática a 25°C. As propriedades térmicas dos géis foram as esperadas para o material, sendo diferentes para cada um dos estruturantes as temperaturas de início de cristalização variaram entre 42 e 47°C e de fusão entre 49 e 59°C. Os géis apresentaram resistência mecânica, sendo que os géis mais resistentes foram os de 4% (m/m) da cera clarificada e purificada e da fração solúvel em etanol. O comportamento reológico foi típico para géis termorreversíveis com aumento de viscosidade nas temperaturas entre 40 e 44°C, coincidindo com a temperatura encontrada por DSC. A microestrutura observada para os organogéis foi característica de uma rede tridimensional organizada para as amostras contendo cera cristalizada e purificada e a fração solúvel em etanol e desorganizada para o organogel obtido pela fração insolúvel em etanol. Os organogéis apresentaram estabilidade por 7 dias em diferentes condições de temperatura (5, 25 e 35°C) com exceção do organogel obtido com a fração insolúvel em etanol cristalizada em 25°C. Os organogéis formados apresentaram baixa resistência mecânica e térmica, sendo de fácil fusão, porém podem ser adequados para aplicações industriais como substitutos de gorduras moles / Abstract: Fats and oils present a key role in our diet, as nutrients and as structure for many food products that we consume such as margarines. Solid fats rich in saturated fatty acids were used during a long time to obtain food products with desirable technological characteristics of hardness and texture, being replaced by rich in trans fatty acids fats. With the discovery of the negative health effects of trans fatty acids, these materials were replaced by high technology fats such as chemically modified interesterified fats that again used saturated fatty acids to get the desirable texture. Technological alternatives to reduce the intake of saturated fatty acids are needed. Soybean oil is a low cost, highly available and low in saturated fatty acids source of lipid, being adequate for the development of new technological fats using vegetable waxes as structuring agents, forming organogels. Organogels are mixtures that are capable of self-support, formed by a liquid continuous phase and a structuring agent, in this case wax. Sugarcane wax is interesting because of its high productive potential presented in Brazil and because of its physical characteristics. The goal of this study was to evaluate the potential of sugarcane wax and its hot ethanol soluble and insoluble fractions to form organogels and evaluate the physical behavior of these organogels. The three structurants presented the ability to form organogels at static crystallization at 5°C at the studied concentration (1, 2, 3 and 4%, w/w), but the hot ethanol insoluble fraction wasn¿t capable of forming stable organogels at static crystallization at 25°C. The thermal properties of the studied organogels were as expected for the kind of material, being different for each structurant in a range of 42 to 47°C for crystallization and 49 to 59°C for melting. The organogels presented mechanical hardness, being the most resistant the 4% (w/w) of clarified and purified wax and hot ethanol soluble fraction. The organogels also presented a typical rheological behavior presenting thermoreversibility and an increase of viscosity at the temperature range of 40 to 44°C, similar to measure on DSC. The observed microstructure was a tridimensional organized network for the samples clarified and purified sugarcane wax and hot ethanol soluble fraction and more disorga nized for the hot ethanol insoluble fraction. The organogels presented stability for 7 days at different temperature conditions (5, 25 and 35°C) with the exception being the hot ethanol insoluble fraction crystallized at 25°C. The developed organogels presented low mechanical and thermal resistance, being easily melted, however they can be adequate for technological application as replacement for soft fats / Mestrado / Tecnologia de Alimentos / Mestre em Tecnologia de Alimentos
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Associations Between Variants in the NF- κB1 Gene, Alone or in Combination with Saturated Fats, and Anthropometric Traits in Young AdultsBauman-Fortin, Jeremy January 2017 (has links)
Animal studies have shown that chronic high consumption of saturated fat (SF) leads to hypothalamic inflammation and ultimately, alters appetite control. This has been shown to be partly due to an increase in the activity of the transcription factor Nuclear Factor-κB (NF-κB), a major regulator of the inflammatory response. The goal of the study was to first confirm the association between SF measurements and anthropometric traits, then to determine the association between single nucleotide polymorphisms (SNPs) in the NF-κB1 gene and body mass index (BMI) and waist circumference (WC), and finally, to test the interaction between variants in this gene and dietary SF and circulating saturated fatty acids (CSFA) on these anthropometric traits in young adults. A significant positive association was identified between quartiles of CSFA and anthropometric measurements in the total sample (BMI: p = 0.0003, WC: p = 0.0001) and in South Asians (BMI: p = 0.004, WC: p = 0.01), but only marginally among Caucasians (BMI: p = 0.08, WC: p = 0.051) and East Asians (BMI: p = 0.13, WC: p = 0.053). After correcting for false discovery rate, carriers of the T allele in SNP rs4648022 had higher BMI and WC compared to those with the dominant CC genotype (p = 0.0003 and p = 0.0001, respectively). Among Caucasians, there was a significant interaction between SNPs in the NF-κB1 gene and quartiles of CSFA on WC for rs4648095 (p = 0.002). Thus, certain SNPs in the NF-κB1 gene appear to influence BMI and WC and also to modify the association between CSFA and anthropometric traits.
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Inheritance and legacy: a phenomenological explorationLeoni, Giacomo 08 April 2016 (has links)
The aim of this dissertation is to analyze and discuss the individual experience of cultural legacy and inheritance, intended as the transmission of an immaterial product, from the perspective of continental philosophy, and especially through the lens of phenomenology. In particular, I discuss why the conventional way of approaching the matter in terms of tradition is unsatisfying when faced with the deeply personal nature of the Inheritance/Legacy phenomenon.
I analyze the concept of `content' as the intellectual object to be transmitted and received in the process, and define it in terms of fragmentability and inclusiveness: what is the minimal notion that we can still inherit? What is the largest conglomerate of ideas that we can approach as one content?
I introduce the fundamental notion of cultural density, as an alternative to culture in the discussion of the individual approach to contents. In particular, I define cultural density as the sum of all possible contents potentially available to an individual at any given time.
Then, I move to the analysis of the moment of attention, as the locus of actualization of the contents, which are available in one's cultural density and, through attention, move into the interpretative space of inheritance. I also distinguish between attention and attentiveness.
The core of my dissertation focuses in turn on Inheritance (the process of receiving a content from a previous author and making it ours) and Legacy (the creation of cultural contents in the perspective of a future receiver). I analyze their temporal relation and their complex interaction with our perception of time. I show how they are interconnected and how they both rely on narration (and specifically on self narration as a form of re-presentation) to be brought into actuality.
Finally, I deal with their co-dependence and show how the reliance of Inheritance and Legacy on each other (with each needing the other to come first) gives rise to an apparent paradox. I suggest the notion of a saturated phenomenon (elaborated by Marion) to solve it, with an invitation to conceive the inconceivable (following Derrida and Levinas).
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Isogeometric Analysis of Thermo-Hydro-Mechanical Processes in Variably Saturated SoilsShahrokhabadi, Shahriar 10 August 2018 (has links)
The main objective of this research is to present a robust numerical framework based upon Isogeometric analysis (IGA) for simulation of thermo-hydro-mechanical (THM) processes in variably saturated soils. The proposed platform employs the Bézier extraction operator to connect IGA to the conventional finite element analysis (FEA), allowing to take advantage of features offered by the two methods. In the first part, the formulation and numerical implementation for fully coupled numerical simulation of THM problems in saturated porous media are presented. The results are compared against analytical solutions and experimental tests available in the literature. In the second part, the proposed method is used to study the temperature effect on the hydro-mechanical response of sd supporting hydrocarbon pipelines, an aspect that has been overlooked in the majority of previous studies. The results highlight the need for considering nonisothermal behavior in different analysis and design stages of sd-buried pipelines. In the third part, the proposed IGA-FEA framework is extended to evaluate the nonisothermal elasto-plastic behavior of unsaturated soils. Drucker-Prager yield surface is used as criterion to limit the modified effective stress where the model follows small strain, quasi-static loading conditions. The framework is used to simulate strain localization of unsaturated dense sand subjected to undrained compression loading. In comparison with FEA, the present method smoothly distributes plastic strain over the adjacent elements. The parametric study highlights the importance of considering temperature effects in elasto-plastic analysis of unsaturated soils.
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The Influence of Myofilament Protein Modification and Myocardial Insulin Resistance on Pathologic Left Ventricular FunctionChristopher, Bridgette A. January 2011 (has links)
No description available.
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SPATIAL PATTERNS OF SATURATED HYDRAULIC CONDUCTIVITY AND ITS CONTROLLING FACTORS FOR FORESTED SOILSCAPESSOBIERAJ, JOSEF ALLEN 04 September 2003 (has links)
No description available.
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The Role of High Saturated Fatty Acid Diets on Skeletal Muscle Metabolism and InflammationHaynie, Kimberly Rebekah 22 December 2011 (has links)
The purpose of this study was to examine the relationship between metabolic adaptive response to 5 days of high SFA feeding, independent of positive energy balance, and diet-induced agonism of pro-inflammatory pathways. A secondary aim was to determine if the metabolic adaptive response in skeletal muscle to a single, high fat meal was altered by 5 days of high saturated fat feeding. Twelve college-age, non-obese males were studied and skeletal muscle samples were obtained prior to and concluding the consumption of a high SFA diet. In a subset of volunteers (N=6), we fed participants a high fat meal after the initial skeletal muscle biopsy and measured changes in postprandial endotoxin concentrations for four hours following the meal challenge. A second biopsy was obtained four hours after the meal challenge. Skeletal muscle samples were used to measure fatty acid oxidation, glucose oxidation, oxidative enzyme activities, mRNA expression of metabolic targets, and phosphorylation and total content of inflammatory proteins. In response to five days of high SFA feeding, skeletal muscle glucose and complete palmitate oxidation were significantly reduced as was the ratio of complete to incomplete fatty acid oxidation. Five days of high SFA feeding also attenuated the meal challenge-induced up-regulation of oxidative genes while augmenting postprandial increases in plasma endotoxin concentrations. To assess the relationship between metabolic adaptability and diet-induced inflammatory response we categorized volunteers by the diet induced percent change in fatty acid oxidation. Volunteers who were the least capable to adapt to high SFA feeding displayed the most robust increases in phosphorylation of inflammatory proteins. Lastly, we measured the correlation between the meal challenge associated percent change in oxidative and inflammatory markers in samples obtained prior to and following five days of high SFA feeding. We observed positive associations between the percent change in oxidative and inflammatory markers in samples obtained prior to the high SFA diet that were not observed following five days of high SFA feeding. These findings suggest that diet induced inflammatory response is involved in the regulation of adaptive response to high SFA feeding and that this relationship becomes dysregulated with chronic high SFA intake. / Ph. D.
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Synthesis, structure and pyrolysis of stabilised phosphonium ylides containing saturated oxygen heterocyclesAitken, R.A., Karodia, Nazira, McCarron, H.B., Rouxel, C., Sahabo, Nina Carole, Slawin, A.M.Z. 05 January 2016 (has links)
Yes / A range of twelve stabilised phosphonium ylides containing tetrahydrofuran, tetrahydropyran or 2,2-
dimethyl-1,3-dioxolane rings have been prepared and fully characterised, including one X-ray structure
determination of each type. The X-ray structures confirm the PvC and CvO functions to be syn and all
the compounds undergo thermal extrusion of Ph3PO to give the corresponding alkynes. In some cases
there is also competing loss of Ph3P to give different carbene-derived products and evidence has been
obtained for the generation of 2-phenyloxete in this way. Raising the pyrolysis temperature leads in
several cases to new secondary reactions of the alkyne products involving a sequence of alkyne to vinylidene
isomerisation, intramolecular CH insertion, and retro Diels Alder reaction.
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Healthy Skepticism: The Relationship between Funding Source and Conclusion in Nutrition-Related Scientific Articles on Saturated FatMuskal, Lili 01 January 2019 (has links)
Recently published scientific articles have led to mixed nutritional advice on dietary saturated fatty acids. Lesser et. al (2007) identified that mixed conclusions in scientific articles on sweetened beverages might be attributed industry funding, as articles funded by the beverage industry are four to eight times more likely to report conclusions in favor of the sponsor’s products. This thesis applies Lesser’s methods to determine whether industry funding influences the inconsistent conclusions on saturated fatty acids. This thesis analyzes 100 articles on foods high in dietary saturated fatty acids. While studies with food industry funding are more likely to produce favorable conclusions, this trend is not significant (p= 0.205). On the other hand, the odds ratio of a favorable versus an unfavorable conclusion in articles where investigators disclosed a food industry related conflict of interest is 2.67 (95% CI, 1.03 to 6.88). The prevalence of both industry funding and conflict of interest have increased over time, yet the percent of articles reporting favorable conclusions has not changed over time. This suggests that while industry funding and conflict of interest might skew nutrition research, the mixed conclusions in articles on saturated fatty acids are largely influenced by other factors. Therefore, all nutrition-related scientific articles on saturated fatty acids should be critically evaluated before informing dietary recommendations.
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FLEXIBLE FLOATING THIN FILM PHOTOVOLTAIC (PV) ARRAY CONCEPT FOR MARINE AND LACUSTRINE ENVIRONMENTSTrapani, Kim 16 May 2014 (has links)
The focus of the research is on the development of the concept of floating flexible thin film arrays for renewable electricity generation, in marine and lacustrine application areas. This research was motivated by reliability issues from wave energy converters which are prone to large loads due to the environment which they are exposed in; a flexible system would not need to withstand these loads but simply yield to them. The solid state power take off is an advantage of photovoltaic (PV) technology which removes failure risks associated with mechanical machinery, and also potential environmental hazards such as hydraulic oil spillage. The novelty of this technology requires some development before it could even be considered feasible for large scale installation. Techno-economics are a big issue in electricity developments and need to be scoped in order to ensure that they would be cost-competitive in the market and with other technologies.
Other more technical issues relate to the change in expected electrical yield due to the modulation of the PV array according to the waves and the electrical performance of the PVs when in wet conditions. Results from numerical modelling of the modulating arrays show that there is not expected variation in electrical yield at central latitudes (slightly positive), although at higher latitudes there could be considerable depreciation. With regards to the electrical performance a notable improvement was measured due to the cooling effect, slight decrease in performance was also estimated due to water absorption (of ~ 1.4%) within the panels. Overall results from both economic and technical analysis show the feasibility of the concept and that it is a possibility for future commercialisation.
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