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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.
1

Estudo dos limites de inflamabilidade em mistura etanol-ar-diluente / Study of flammability limits in ethanol-air-diluent mixture

Escalante, Edwin Rios [UNESP] 12 July 2016 (has links)
Submitted by EDWIN SANTIAGO RIOS ESCALANTE null (esre_2808@hotmail.com) on 2016-09-12T20:28:02Z No. of bitstreams: 1 template-feg-2016-VERSÃO FINAL.pdf: 3419531 bytes, checksum: 2e6eca3a01fecef269a3334812ba75d2 (MD5) / Approved for entry into archive by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br) on 2016-09-14T19:40:34Z (GMT) No. of bitstreams: 1 escalante_esr_me_guara.pdf: 3419531 bytes, checksum: 2e6eca3a01fecef269a3334812ba75d2 (MD5) / Made available in DSpace on 2016-09-14T19:40:34Z (GMT). No. of bitstreams: 1 escalante_esr_me_guara.pdf: 3419531 bytes, checksum: 2e6eca3a01fecef269a3334812ba75d2 (MD5) Previous issue date: 2016-07-12 / Agência Nacional de Petróleo, Gás Natural e Biocombustíveis (ANP) / Os limites superior e inferior de inflamabilidade são as concentrações máximas e mínimas de um combustível no ar, respectivamente, na qual uma chama pode se propagar, eles são considerados ferramentas chaves na predição do fogo, avaliando a possibilidade de explosão e projeto de sistemas de proteção. Existe interesse em encontrar os limites de inflamabilidade do etanol misturado com um diluente para pressões reduzidas para o futuro uso desse biocombustível em aplicações aeronáuticas tendo em conta a altitude típica de um avião comercial (<40 000 ft.). Neste trabalho foi desenvolvido experimentalmente a inflamabilidade do combustível líquido: Etanol hidratado e utilizou-se como gás diluente o nitrogênio. A bancada experimental usada, consiste de um recipiente esférico de 20 litros como câmara de aquecimento, uma fonte de ignição por faísca localizada na parte central da câmara. O líquido foi injetado com uma seringa de precisão de 1ml de volume para logo se evaporar no interior da câmara, o nitrogênio e ar foram injetados usando pressões parciais. O método para medir a inflamabilidade foi baseado na ignição elétrica e observação visual da propagação da chama conforme norma ASTM E-681. Primeiro os limites superior e inferior de inflamabilidade foram determinados para elevada temperatura (60℃) e pressão ambiente (101,325 kPa) para comparar os resultados com os dados publicados na literatura científica. Depois procedeu-se trabalhar com pressões reduzidas (80, 60, 40 e 20 kPa) para essa mesma temperatura, finalmente foram realizados testes para uma temperatura maior (110℃) para avaliar a influência da temperatura sobre os limites de inflamabilidade de misturas etanol-ar-diluente, os resultados foram plotados como função da relação e adição de nitrogênio e esses gráficos seguem a mesma tendência de trabalhos publicados na literatura científica. / The upper and lower limits of flammability are the maximum and minimum concentrations of a fuel in the air, respectively, in which the flame can spread; they are considered key tools for predicting fire, evaluating the possibility of explosion and protection system design. There is interest in finding the flammability limits of ethanol mixed with a diluent to reduced pressure for future use this biofuel in aeronautical applications having regard the typical height of a commercial aircraft (<40, 000 ft.). In this experimental work was carried flammability of the liquid fuel: Ethanol hydrate and used as a diluent gas nitrogen. The experimental apparatus consists of a 20 liters spherical vessel as heating chamber, a spark ignition source located in the central part of the chamber. The liquid was injected with a 1 ml syringe precision volume immediately evaporates in the chamber; nitrogen and air were injected using partial pressures. The method for flammability measuring was based in both visual observation electric ignition and flame propagation as defined by ASTM E-681. First, the upper and lower flammability limits were determined to a high temperature (60 ℃) and ambient pressure (101.325 kPa) to compare the results with data published in the scientific literature. After, we proceeded to work at reduced pressures (80, 60, 40 and 20 kPa) to same temperature. Finally, tests were carried out for a higher temperature (110 ℃) to evaluate the influence of temperature on the flammability limits ethanol-air-diluent mixtures, the results were plotted as a function of the relationship and adding nitrogen and these graphs follow the same trend of papers published in scientific literature.
2

Wish to be thinner : Development and Prediction of Disturbed Eating: A Longitudinal Study of Swedish Girls and Young Women

Westerberg Jacobson, Josefin January 2010 (has links)
The overall aim of this thesis was to examine the development and prediction of disturbed eating attitudes in girls aged 7–20 years. The four studies are part of a seven-year longitudinal project including 1279 girls in several age groups (7, 9, 11, 13, 15 years at inclusion) and their parents. Study I showed that among girls aged 11 and 13 years, in addition to a positive relation between disturbed eating attitudes and age, eating attitudes, higher BMI than peers, a less healthy relation to family, and fathers’ eating attitudes, predicted disturbed eating attitudes two years later. Study II demonstrated that girls aged 9–15 years, who wished to be thinner dieted more often, thought that they would be more popular if they were thinner, were skipping meals more often and had a higher BMI, over five years, compared with the girls without such a wish. Study III demonstrated an increasing trend in the wish to be thinner and dieting attempts between the ages of 9 and 18 years. Motives for wishing to be thinner were, e.g., “to feel better about yourself” and “to correspond to the societal ideal”. A majority of the girls adopted healthy weight control practices, but unhealthy and extreme methods were also used. In Study IV, among girls aged 9 and 13 years, a wish to be thinner, fathers’ eating attitudes and mothers’ perfectionism contributed most to the prediction of disturbed eating attitudes seven years later. Protective factors were low BMI and more healthy eating attitudes moderated by high self-esteem, and low-to-medium degree of perfectionism. In conclusion a wish to be thinner, higher BMI than peers, girls’ and fathers’ disturbed eating attitudes, mothers’ perfectionism and a less healthy relation to family predict the development of disturbed eating attitudes in girls. Low BMI and more healthy eating attitudes especially influenced by high self-esteem, and a low-to-medium degree of perfectionism protect against it. The “thin-ideal” is internalized early in girls and it is important to take a critical stand against the thinness ideal in our society, especially in families, and schools. / The IDA-Project
3

Potencial antioxidante do extrato aquoso do fruto do noni em diluente para congelação de sêmen ovino / Antioxidant activity of aqueous extract of noni fruit in thinner to ram semen freezing

Nascimento, Anna Lauren Costa 24 February 2015 (has links)
It is known that antioxidants when added to extenders can contribute to preserving the integrity of sperm cells. How noni is considered a fruit with antioxidant potential, aimed to evaluate the feasibility of ram semen subjected to dilution in medium containing different amounts of aqueous extract of noni (Morinda citrifolia L). Initially noni cropped and then elaborated the aqueous extract to be added to the medium thinner. The fruit was evaluated for its physical and chemical characteristics as presenting results ph = 4.12; Titratable acidity = 8.78%; Soluble solids = 8.18 ° Brix and Vitamin C = 309.43 mg.100-1 content. The aqueous extract produced was evaluated for quantification of total phenolic compounds, antioxidant activity and ability to inhibit lipid peroxidation, with amounts of total phenols of 47.96 ± 1.95 mg Eq. Gálico.100g acid-1 extract. Concentration of 3.0 μg.mL-1 time 30 minutes had antioxidant activity 89.35 ± 2.32% It was observed that only 1.2 ± 0.15 ug / ml of sample is sufficient to reduce the DPPH by 50%. It also exhibited excellent redox ability to inhibit lipid peroxidation in a concentration of 10 μg.mL-1, similar to the synthetic Trolox positive control (p <0.05) at 72 The Extract concentrations and 120μg.mL-1 was able to inhibit lipid peroxidation in the thinner half in 21.75% and 51.32%. Treatments for ram semen freezing differ in the use of thinner medium containing different concentrations of the extract: T1- control without addition; T2 24 mg / mL; T3-72 / mL; T4 - 120 mg / mL. A total of 16 ejaculates were collected, diluted according to the treatments and frozen. After thawing the semen was subjected to heat resistance test (TTR) and evaluated for the subjective motility, sperm vigor, health test hypoosmotic swelling test plasma membrane, supravital test, and the combination of SYBR Green and fluorochrome propidium iodide (PI ), and the status of sperm capacitation and acrosome reaction by clortetracliclina (CTC). The results found for TTR showed T2 with better motility 22.6 ± 9.7; than the other treatments with the addition of extract, while the T1 and T2 treatments showed better effect than T4; in hiposmotic test T3 was superior to T2 after two hours of incubation; T4 showed better preservation of the plasma membrane and the sperm capacitation treatments differ P <0.05 only for trained with sperm acrosome reacted. Also the kinetic analysis was performed using a computerized system at the time of thawing and the percentages for progressive motility in T1, T2, T3 and T4 were 26.9 ± 9.7; 20.1 ± 12.6; 20.7 ± 10.8 and 15.5 ± 9.2 respectively, for the curvilinear velocity parameters (VCL) and the average speed path (VAP) T1 and T2 shown to be superior to T3 and T4, and amplitude lateral displacement of the head (ALH) T4 showed inferiority to the other tested treatments. No difference was observed for straight-line speed (VSL), straightness (STR) and linearity (LIN). The treatments with the addition of aqueous extract of noni showed higher viability than control. / Sabe-se que as substâncias antioxidantes quando adicionadas aos meios diluidores podem contribuir para a preservação da integridade de células espermáticas. Como o noni é considerado um fruto com potencial antioxidante, objetivou-se avaliar a viabilidade de sêmen ovino submetido a diluição em meio contendo diferentes quantidades de extrato aquoso de noni (Morinda citrifolia L). Inicialmente o noni foi colhido e em seguida elaborou-se o extrato aquoso a ser adicionado ao meio diluidor. O fruto foi avaliado quanto as suas características físico-químicas apresentando como resultados ph=4,12; Acidez titulável = 8,78%; Sólidos solúveis = 8,18°Brix e teor de Vitamina C = 309,43 mg.100-1. O extrato aquoso produzido foi avaliado quanto a quantificação de compostos fenólicos totais, atividade antioxidante e capacidade de inibição da peroxidação lipídica, apresentando quantidades de fenóis totais de 47,96 ± 1,95 mg Eq. Ácido Gálico.100g-1 do extrato. Na concentração de 3,0 μg.mL-1 no tempo de 30 minutos apresentou uma atividade antioxidante de 89,35 ± 2,32 %, sendo observado que apenas 1,2± 0,15 μg/mL da amostra é suficiente para reduzir o radical 2,2-difenil-1- picril-hidrazila (DPPH) em 50%. Também apresentou uma excelente capacidade redox em inibir a lipoperoxidação na concentração de 10 μg.mL-1, sendo semelhante ao controle positivo sintético Trolox (p<0,05) O extrato nas concentrações de 72 e 120μg.mL-1 foi capaz de inibir a lipoperoxidação no meio diluídor em 21,75% e 51,32%. Os tratamentos para congelação de sêmen ovino diferiram quanto a utilização de meio diluidor contendo diferentes concentrações do extrato: T1- controle, sem adição; T2- 24 μg/mL; T3-72 μg/mL; T4 - 120 μg/mL. Um total de 16 ejaculados foram coletados, diluídos de acordo com os tratamentos e congelados. Após a descongelação o sêmen foi submetido ao teste de termorresistência (TTR) e avaliado quanto a motilidade subjetiva, vigor espermático, teste de integridade de membrana plasmática pelo teste hiposmótico, teste supravital, e pela combinação de fluorocromos SYBR Green e iodeto de propídio (IP), e o status de capacitação espermática e reação acrossomal pela clortetracliclina (CTC). O resultado encontrado para o TTR mostrou o T2 com melhor motilidade 22,6 ± 9,7; que os demais tratamentos com adição de extrato, enquanto que os tratamentos T1e T2 apresentaram melhor vigor que o T4; no teste hiposmótico o T3 mostrou-se superior ao T2 após duas horas de incubação; o T4 mostrou melhor preservação da membrana plasmática e quanto a capacitação espermática os tratamentos diferiram P<0,05 apenas para espermatozoides capacitados com acrossomo reagido. Também foi realizada a análise de cinética através de sistema computadorizado no momento da descongelação e os percentuais para motilidade progressiva nos tratamentos T1, T2, T3 e T4 foram 26,9±9,7; 20,1±12,6; 20,7±10,8 e 15,5±9,2 respectivamente, para os parâmetros velocidade curvilinear (VCL) e velocidade do percurso médio (VAP) os tratamentos T1 e T2 mostraram-se superior ao T3 e T4, e para amplitude de deslocamento lateral da cabeça (ALH) o T4 apresentou inferioridade aos outros tratamentos testados. Não se observou diferença para velocidade em linha reta (VSL), retilinearidade (STR) e linearidade (LIN). Os tratamentos com adição de extrato aquoso de noni apresentaram maior viabilidade que o tratamento controle.

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