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Preharvest ethylene and postharvest curing effects on baked sweet potato (Ipomoea batatas L. Lam) quality and prevention of sprouting on cured sweet potatoesSheibani, Ershad 06 August 2011 (has links)
The effect of preharvest foliar applications of ethephon and postharvest curing on baked sweet potatoes (Ipomoea batata) were analyzed. Ethylene had negative effects on appearance of baked roots while curing increased the total phenolics in sweet potatoes. Panelists preferred the non-ethylene treated and green or cured over ethylene treated sweet potatoes with respect to texture, color and flavor. No differences in chemical or color properties were found between treatments. The effect of curing time (0, 7, 14 days) on baked sweet potatoes was studied. Curing caused more browning on flesh of sweet potatoes. Moreover, panelists preferred the texture of the green over the cured roots but did not find any differences in flavor sensory quality. The effect of hot water treatment on sprouting and spoilage of cured sweet potatoes was investigated. The most effective treatment was at 53-56 °C for less than 10 min, resulting in less than 60% (control=80%).
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Methods to Streamline Laminate Composite Design, Analysis, and OptimizationHepworth, Ammon Ikaika No Kapono 10 March 2010 (has links) (PDF)
Advanced composite materials have seen major market growth in recent years due to their high strength and low weight properties. These materials are often made using a process that creates a composite laminate by stacking several composite layers together. However, the design, analysis and optimization of laminate composite materials are often a labor intensive process when done manually. This thesis discusses CAD independent algorithms that are integrated into commercial CAD tools to streamline these processes. Methods have been developed to automatically create 3D ply geometry for a laminate composite lay-up, streamline the creation of a laminate composite finite element model and optimize the composite lay-up for a multi-layered laminate composite part. Integrating a CAD independent geometry kernel into the NX laminate composite design automation application significantly improves the run time of that application. In addition, the automated composite finite element tool creates laminate composite finite element models that are more detailed than those made with zone based methods. This tool will save engineers, who are making laminate composite finite element models manually, dozens of hours of work per model. The automated composite finite element tool can also be integrated into an optimization framework, used in conjunction with a method to automatically apply boundary conditions, to create an effective optimization of a laminate composite part.
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Minimum-weight design of compressively loaded stiffened panels for postbuckling responsePerry, Christine Ann 13 February 2009 (has links)
A computationally efficient procedure, NLPANOPT, is developed for the preliminary design of minimum-weight thin-walled stiffened composite panels loaded in uniaxial compression based on a geometrically nonlinear analysis. An approximate, semi-analytical nonlinear analysis code, NLPAN, which requires buckling eigenfunction information from the buckling analysis code, VIPASA, is linked with the optimization code ADS. A blade-stiffened and T-stiffened panel are designed for specified loads using NLPANOPT for postbuckling response and PASCO for buckling-critical response. Comparisons of panel weight and imperfection sensitivity between the NLPANOPT designs and PASCO designs are presented. In general, the designs obtained with NLPANOPT are lighter and less imperfection sensitive than the designs obtained with PASCO. The nonlinear analysis allows for a more accurate prediction of the true strength of the stiffened structure, by accounting for postbuckling strength and modal interaction. The effect of laminate stacking sequence is also investigated. The current design procedure requires the stacking sequence to be prescribed, proving to be a limitation in the design procedure. / Master of Science
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Active encapsulation of diclofenac sodium into liposomes for ophthalmic preparationsAlonjang, Evelyne Nguelweh January 2018 (has links)
>Magister Scientiae - MSc / Liposomes as a drug carrier in the pharmaceutical industry has gained currency since its
discovery in 1965 by Bangham A. D. Liposomes have been shown to improve bioavailability
as they can be delivered to target sites and possess sustained release properties which could
be used to mitigate certain weaknesses associated with current diclofenac sodium eye drops.
Diclofenac sodium (DNa) eye drop is a sterile Nonsteroidal Anti-inflammatory Drug
(NSAID) with diclofenac sodium as its active ingredient. It is indicated for the lessening of
ocular pain, prevention of miosis in eye operations, easing of postoperative inflammation and
cystoids macular edema. The residence time of eye drops after application has been found to
be 1-2 minutes as a result of continuous production of tears diluting the active ingredient,
draining the eye drops into the nasolacrimal path, and eliminating it during blinking. As a
result of the active ingredient not residing at the target site for the required duration, more
frequent administration and medication is required and the risk of non-compliance is
increased.
Given the aforementioned potential of liposomes to redress the above weaknesses of current
eye drops (dosage form) available for diclofenac sodium ophthalmic application, this study
sought to encapsulate diclofenac sodium into liposomes for ophthalmic application.
The main components of liposomes (cholesterol and phosphotidylcholine) and incubation
time were set as the independent variables while percentage encapsulation, polydispersity
index (PDI) and drug release profile constituted the dependent variable. Using analysis of
variance (ANOVA) and t-test statistics, the interaction between the independent variables and
their effect on the dependent variables were tested.
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Degradação fotocatalítica de nicotina em solução aquosa empregando ZnO, TiO2 e catalisadores não convencionais em suspensãoFranco, Marcela Andrea Espina de January 2014 (has links)
O presente trabalho estuda a degradação fotocatalítica da nicotina em solução aquosa, um alcaloide altamente tóxico que tem sido detectado em efluentes, águas subterrâneas e água mineral. Os experimentos foram realizados em um reator batelada sob irradiação ultravioleta, tendo sido avaliadas três principais variáveis: concentração inicial do contaminante, concentração de catalisador e pH inicial da solução. Foram realizados dois planejamentos de experimentos para os catalisadores comerciais ZnO e TiO2, com o objetivo de encontrar a melhor condição para promover a degradação da nicotina em água. Outros catalisadores, preparados a partir de resíduos industriais e laboratoriais, foram testados nas condições otimizadas. O método analítico empregado para quantificar a nicotina nas amostras foi a cromatografia líquida de alta eficiência, o que permitiu registrar a formação de intermediários e subprodutos de reação. Os resultados experimentais demostraram que a degradação da nicotina por fotocatálise heterogênea é um processo bastante eficiente. Em ambos os planejamentos, o pH foi a variável que exerceu o maior efeito sobre a degradação, sendo este fortemente positivo. Já a concentração inicial de nicotina exerceu efeito negativo sobre a resposta e a concentração de catalisador em suspensão exibiu um ponto ótimo, que correspondeu a 0,91 g.L-1 para o ZnO, e 1,20 g.L-1 para o TiO2. Ensaios foram realizados nas condições otimizadas encontradas, onde cerca de 98% da molécula foi degradada utilizando ZnO em suspensão e 88% empregando TiO2, em uma hora de reação. A degradação fotocatalítica da nicotina demonstrou seguir uma cinética de pseudoprimeira ordem dentro do tempo de reação de 60 minutos, para os dois catalisadores comerciais. Entre os catalisadores não convencionais que foram testados, aquele que demonstrou o maior percentual de degradação foi obtido a partir de resíduo de uma indústria petroquímica, cerca de 43%. / The present work studies the photocatalytic degradation of nicotine in aqueous solution. This alkaloid is highly toxic and it has been detected in wastewater, groundwater and mineral water. The experiments were performed in a batch reactor under ultraviolet radiation. Three main variables of process were evaluated: initial concentration of pollutant, catalyst concentration and initial pH of the solution. Two experimental designs were performed for commercial catalysts ZnO and TiO2. The purpose was to find the best condition to promote the nicotine degradation in water. Other catalysts prepared from industrial and laboratory waste were tested under the optimized conditions. Analytical method used to quantify nicotine and its degradation products in all samples was high performance liquid chromatography. Experimental results showed that nicotine degradation by heterogeneous photocatalysis is a very efficient process. In both designs, initial pH was the most significant variable which has a strong positive effect. Initial nicotine concentration showed a negative effect, and catalyst concentration exhibited an optimal value for both commercial catalysts: 0,91 g.L-1 using ZnO, and 1,20 g.L-1 with TiO2. At the best conditions, about 98% of the molecule was degraded using ZnO and 88% with TiO2. Photocatalytic nicotine degradation followed a pseudo first order kinetic until 60 minutes of reaction for both commercial catalysts. Among the non-conventional catalysts tested, the one prepared from a petrochemical industry residue exhibited the highest photocatalytic degradation, about 43%.
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Investigation of an IsoTruss Structure as a Compliant Member Used in Bending and TorsionJacobson, Jens Garret 01 December 2018 (has links)
An investigation of IsoTruss structures in bending and torsion was conducted. A model was developed in ANSYS APDL where bay length and longitudinal member to helical member cross-sectional area ratio could be varied while holding the diameter constant. The model was validated using previously reported values from analytical models and empirical data. The model was used to make predictions of a specific geometry that was manufactured, tested and compared against the model. 12 specimens were built and tested. In flexure, empirical data had a percent error with respect to the model ranging from 10.9 to 65.4% with one outlier at 94.1%. In torsion, the empirical data had a percent error with respect to the model ranging from 0.4 to 34%. The test data exhibited similar trends compared to the model. An IsoTruss structure built to maximize torsional rigidity should have a diameter and bay length such that its helical angle is between 55 and 60 degrees. The inclusion of longitudinal members has a negligible impact on rigidity. Flexural rigidity is maximized with longitudinal members and with a minimal helical angle, placing helical members more in the direction of the longitudinal members. In order to minimize flexural rigidity, the longitudinal members should be removed from the design and the helical member angle should be maximized up to 80 degrees.
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Modelling The Fresh Properties Of Self Compacting Concrete Utilizing Statistical Design Of Experiment TechniquesEroglu, Levent 01 February 2007 (has links) (PDF)
Self compacting concrete (SCC) is first developed in Japan in the late 1980s in order to overcome the consolidation problems associated with the presence of congested reinforcement. It is also termed as a high performance concrete, as it can flow under its own weight and completely fill the formworks. As the fresh properties of SCC are quite important, mix design of a SCC is performed by considering various workability related fresh properties. Therefore, a well designed SCC should satisfy all requirements of a hardened concrete, besides its superior workability properties.
The aim of this research is to assess the effects of some basic ingredients of SCC on the fresh properties of SCC. This will be performed by applying design of experiment techniques and obtaining significant statistical models, which will give valuable information about the effects of the model parameters on the rheology and fresh state characteristics of SCC.
In this research program, four different variables / use of fly ash replacement, use of high range water reducing admixture (HRWRA), use of viscosity modifying admixtures (VMA) and water-cementitious material ratio, are considered as the variables of the experimental design. Central Composite Design (CCD), a design of experiment technique, is employed throughout the experimental program and a total of 21 mixtures of concrete are cast. Slump flow, V-funnel, L-box, sieve segregation, initial and final setting time tests are performed, furthermore / to investigate the effects of these variables to the rheology of SCC, relative plastic viscosity and relative yield stress, which are the parameters of Bingham Model are measured with the help of a concrete rheometer.
As a result of the experimental program, the fresh state properties of SCC are expressed by mathematical equations. Those equations are then used in order to explain the effects of fly ash replacement, HRWRA and VMA concentration, and the w/cm ratio on the fresh state properties of SCC. According to the derived models, it is stated that the water-cementitious material ratio of the concrete mixture is the most effective parameter on the flowability and passing ability of SCC beside the other parameters utilized in this research as its coefficient was the highest in the related models.
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Degradação fotocatalítica de nicotina em solução aquosa empregando ZnO, TiO2 e catalisadores não convencionais em suspensãoFranco, Marcela Andrea Espina de January 2014 (has links)
O presente trabalho estuda a degradação fotocatalítica da nicotina em solução aquosa, um alcaloide altamente tóxico que tem sido detectado em efluentes, águas subterrâneas e água mineral. Os experimentos foram realizados em um reator batelada sob irradiação ultravioleta, tendo sido avaliadas três principais variáveis: concentração inicial do contaminante, concentração de catalisador e pH inicial da solução. Foram realizados dois planejamentos de experimentos para os catalisadores comerciais ZnO e TiO2, com o objetivo de encontrar a melhor condição para promover a degradação da nicotina em água. Outros catalisadores, preparados a partir de resíduos industriais e laboratoriais, foram testados nas condições otimizadas. O método analítico empregado para quantificar a nicotina nas amostras foi a cromatografia líquida de alta eficiência, o que permitiu registrar a formação de intermediários e subprodutos de reação. Os resultados experimentais demostraram que a degradação da nicotina por fotocatálise heterogênea é um processo bastante eficiente. Em ambos os planejamentos, o pH foi a variável que exerceu o maior efeito sobre a degradação, sendo este fortemente positivo. Já a concentração inicial de nicotina exerceu efeito negativo sobre a resposta e a concentração de catalisador em suspensão exibiu um ponto ótimo, que correspondeu a 0,91 g.L-1 para o ZnO, e 1,20 g.L-1 para o TiO2. Ensaios foram realizados nas condições otimizadas encontradas, onde cerca de 98% da molécula foi degradada utilizando ZnO em suspensão e 88% empregando TiO2, em uma hora de reação. A degradação fotocatalítica da nicotina demonstrou seguir uma cinética de pseudoprimeira ordem dentro do tempo de reação de 60 minutos, para os dois catalisadores comerciais. Entre os catalisadores não convencionais que foram testados, aquele que demonstrou o maior percentual de degradação foi obtido a partir de resíduo de uma indústria petroquímica, cerca de 43%. / The present work studies the photocatalytic degradation of nicotine in aqueous solution. This alkaloid is highly toxic and it has been detected in wastewater, groundwater and mineral water. The experiments were performed in a batch reactor under ultraviolet radiation. Three main variables of process were evaluated: initial concentration of pollutant, catalyst concentration and initial pH of the solution. Two experimental designs were performed for commercial catalysts ZnO and TiO2. The purpose was to find the best condition to promote the nicotine degradation in water. Other catalysts prepared from industrial and laboratory waste were tested under the optimized conditions. Analytical method used to quantify nicotine and its degradation products in all samples was high performance liquid chromatography. Experimental results showed that nicotine degradation by heterogeneous photocatalysis is a very efficient process. In both designs, initial pH was the most significant variable which has a strong positive effect. Initial nicotine concentration showed a negative effect, and catalyst concentration exhibited an optimal value for both commercial catalysts: 0,91 g.L-1 using ZnO, and 1,20 g.L-1 with TiO2. At the best conditions, about 98% of the molecule was degraded using ZnO and 88% with TiO2. Photocatalytic nicotine degradation followed a pseudo first order kinetic until 60 minutes of reaction for both commercial catalysts. Among the non-conventional catalysts tested, the one prepared from a petrochemical industry residue exhibited the highest photocatalytic degradation, about 43%.
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Estudo da obtenção de açúcares redutores totais a partir do bagaço de laranja (Citrus sinenses) por hidrólises ácida diluída e enzimáticaNogueira, Danielle Pires 18 April 2016 (has links)
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Previous issue date: 2016-04-18 / Due to the recent research for new fuels from renewable sources ethanol has been gaining momentum, because it can be produced from diverse raw materials, such as agro-industrial residues. The objective with this work was to study the production of reducing sugar by dilute acid, and enzymatic hydrolysis of the orange bagasse from juice industry. The orange bagasse was collected, cut into pieces, and crushed. Granulometry, and the contents of moisture, ashes, holocellulose, cellulose, hemicelulose, soluble and insoluble lignin were determined. The pre-treatment was done with calcium hydroxide following what was previously tested by Silva et al. (2013). A pre-test of the enzymes combination was done using 2 g of pre-treated biomass, in dry base, using 3 FPU/mL of cellulase, and 0 U/g and 3 U/g of xylanase. For the hydrolysis two central composite factorial 2³ designs were done, with the answer in total reducing sugars (ART). For the dilute acid hydrolysis the factors were HCl concentration, temperature, and time, and for the enzymatic the concentrations of cellulase and xylanase and time. The granulometry showed that 47.75% of the biomass with diameter over 0.833 mm, 32.84% of the biomass with an average diameter of 0.564 mm, and 19.41% of the biomass with diameter under 0.295 mm. The moisture content prior to drying was 84.69% and 7.38%, the ashes content was 3.79%. The cellulose content was 22.90% and the hemicellulose was 3.39%. The lignin content was 9.90%. The reducing sugar results for the acid hydrolysis varied from 9.32±0.68 mg ART per g of biomass to 30.15±0.31 mg ART per g biomass, the most significant factor was temperature, and the least was time. It was not possible to find the optimum region with the studied factors. The reducing sugar results for the enzymatic hydrolysis varied from 75.33±3.82 mg ART per g biomass to 99.66±0.62 mg ART per g biomass, the most significant factor was the cellulase concentration, and the least significant the xylanase concentration. The studied factors did not show the optimum region to maximize the reducing sugars content. The enzymatic hydrolysis produced larger concentrations of reducing sugars than the acid hydrolysis. / Frente as recentes buscas por novos combustíveis de fontes renováveis o etanol de segunda geração tem ganhado força, por poder ser produzido a partir de diversas matérias primas lignocelulósicas, como os resíduos agroindustriais. Objetivou-se com este trabalho estudar a geração de açúcares redutores por hidrólises ácida diluída e enzimática do bagaço de laranja proveniente da indústria de suco. O bagaço de laranja foi coletado, cortado, seco e moído. Granulometria, umidade, cinzas, concentrações de holocelulose, celulose, hemicelulose e lignina solúvel e insolúvel foram determinadas. O pré-tratamento foi realizado com hidróxido de cálcio de acordo com o previamente testado por Silva et al. (2013). Foi realizado um pré-teste da combinação das enzimas. Para as hidrólises foram feitos dois planejamentos fatoriais do tipo composto central 2³, com resposta em açúcares redutores totais (ART). Para a hidrólise ácida diluída os fatores estudados foram concentração de HCl, temperatura e tempo de hidrólise, na enzimática as concentrações de celulase e hemicelulase e o tempo. Na análise granulométrica encontrou-se 47,75% da biomassa com diâmetro superior a 0,833 mm, 32,84% de biomassa com diâmetro médio de 0,564 mm e 19,41% com diâmetro inferior a 0,295 mm. A umidade da biomassa antes da secagem foi de 84,69%, depois da secagem de 7,38% e as cinzas 3,79%. O conteúdo de celulose foi de 22,90% e o de hemicelulose 3,39%. O conteúdo de lignina foi de 9,90%. Houve uma perda de massa média de 30,03% no pré-tratamento. O pré-teste indicou um efeito positivo na combinação das enzimas para geração de açúcares redutores. Os resultados de açúcares redutores da hidrólise ácida variaram de 9,32±0,68 mg ART por g de biomassa a 30,15±0,31 mg ART por g biomassa, o fator mais significativo foi a temperatura e o menos o tempo, não foi possível encontrar a região ótima com os fatores estudados. Os resultados de açúcares redutores da hidrólise enzimática variaram de 75,33±3,82 mg ART por g biomassa a 99,66±0,62 mg ART por g biomassa, o fator mais significativo foi a concentração de celulase e o menos a concentração de xilanase. Com os fatores estudados não foi possível encontrar a região ótima de geração de açúcares redutores. A hidrólise enzimática gerou maiores concentrações de açúcares redutores que a hidrólise ácida.
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Ozonização de sementes de milho durante a secagem / Decontamination of corn seeds using ozone gas during dryingZanardi, Bruna 26 June 2017 (has links)
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Previous issue date: 2017-06-26 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Corn (Zea mays) for being a culture rich in starch has more propensity to develop fungi during storage than other cultures. In this context, the aim of this work was to evaluate the use of ozone gas during drying as a sanitizing agent in corn, determining the best combination of temperature and time of application of O3 during drying, on the count of fungal colonies, the effect on the physical qualities of the grain, and to determine and shape the drying curves of corn seeds using ozone gas. The corn seeds used were the cultivar Agroeste AS1661 PRO with water content of 19.21 (b. u). The drying process was carried out in experimental dryer under controlled temperatures of 30, 40 and 50 °C and ozonation times of 5, 10, and 15 minutes, until they reached 11 ± (b. u). The Mathematical Modeling of Diffusion was the approach that best adjusted to experimental data of this cultivar. After the drying process, the seeds continued to present high germination rate, electric conductivity and tetrazolium without changes. Regarding fungal decontamination, it was observed that in comparison to the field control there was a high percentage of decontamination. After 45 days of storage, seeds maintained their physiological quality obtained after drying with ozone. About fungal decontamination, there was an increase in the amount of fungal colonies in treatments in which there was a combination of 50 °C and 5 or 15 minutes of ozone, due to the fact that this gas is less stable at high temperatures. / O milho (Zea mays) por ser uma cultura rica em amido tem mais propensão a desenvolver fungos durante o armazenamento do que outras culturas. Neste contexto, o objetivo deste trabalho foi avaliar a utilização do gás ozônio durante a secagem como agente sanitizante em grãos de milho, determinando a melhor combinação entre temperatura e tempo de aplicação de O3 durante a realização da secagem, na contagem de colônias fúngicas, o efeito sobre as qualidades físicas dos grãos e determinar e modelar as curvas de secagem para sementes de milho utilizando gás ozônio. Foram utilizadas sementes de milho da cultivar Agroeste AS1661 PRO com teor de água em 19,21 (b.u). O processo de secagem foi realizado em secador experimental sob temperaturas controladas de 30, 40 e 50 °C e tempo de ozonização de 5, 10 e 15 minutos, até que atingissem 11± (b.u). O modelo matemático de aproximação da difusão foi o que melhor se ajustou aos dados experimentais da cultivar. Após o processo de secagem, as sementes continuaram a apresentar elevada germinação, condutividade elétrica e tetrazólio sem alterações. Em relação à descontaminação fúngica, observa-se que em comparação ao controle de campo houve elevado percentual de descontaminação. Após 45 dias de armazenagem, as sementes mantiveram a qualidade fisiológica obtida após a secagem com ozônio. Sobre a descontaminação fúngica, nota-se aumento da quantidade de colônias fúngicas nos tratamentos em que houve combinação de 50 °C e 5 ou 15 minutos de ozônio, o que deve-se ao fato do gás ser menos estável a altas temperaturas.
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