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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.
11

AnÃlise da composiÃÃo das cinzas do bagaÃo do pedÃnculo do cajà (Anacardium occidentale L.) e sua atividade antifÃngica in vitro contra espÃcies de Fusarium / Compositional analysis of cashew (Anacardium occidentale L.)peduncle bagasse ash and its in vitro antifungal against fusarium species

MÃrcia Machado Marinho 18 March 2011 (has links)
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / O Cajueiro (Anacardium occidentale L.) à uma planta com uma grande importÃncia social e econÃmica no Nordeste do Brasil. O bagaÃo do pedÃnculo do caju à uma das maiores fontes de resÃduos (90-94%) produzidos pela indÃstria cajueira. Neste estudo, foram preparadas cinzas do bagaÃo e submetidas à anÃlise da composiÃÃo e a testes de atividade antifÃngica in vitro contra espÃcies de Fusarium. Esta anÃlise indicou uma cristalinidade em torno de 73%, correspondendo Ãs seguintes fases solÃveis: carbonato Ãcido de potÃssio - KHCO3 (39,54%), sulfato de potÃssio - K2SO4 (24,87%), e estruvita-K - MgKPO4 â 6H2O (8,59%). As fases amorfas (cerca de 27%) foram identificadas como a fraÃÃo insolÃvel de cinzas. A soluÃÃo apresentou alta atividade antifÃngica contra F. oxysporum, F. moniliforme e F. lateritium. Sua aÃÃo foi maior do que o Cercobin (tiofanato metÃlico), indicando uma possÃvel utilizaÃÃo como um agente antifÃngico nÃo tÃxico. / Cashew (Anacardium occidentale L.) is a plant with a highly social and economic importance in Northeast Brazil. Cashew peduncle bagasse is one of the greatest sources of residues (90â94%) produced by the cashew agronomic industry. In this study, we prepared cashew peduncle bagasse ashes and submitted them to compositional analysis and tests for antifungal activity in vitro against Fusarium species. This analysis indicated a crystallinity around 73%, corresponding to the following soluble phases: acid potassium carbonate- KHCO3 (39.54%), potassium sulfate - K2SO4 (24.87%), and struvite-K - MgKPO4Â6H2O (8.59%). The amorphous phases (around 27%) were identified as the insoluble fraction of ashes. The solution showed high antifungal activity against F. oxysporum, F. moniliforme and F. lateritium. This activity of this product was greater than that of Cercobin (thiophanate-methyl), indicating a possible use of this material as a non-toxic antifungal agent.
12

Desenvolvimento, maturação e armazenamento de pedúnculos de cajueiro anão precoce CCP-76 sob influência do cálcio / Developing, maturation and storage cashew apples of the clone CCP-76 under the influence of calcium

Raimundo Wilane de Figueiredo 17 March 2000 (has links)
Três experimentos foram desenvolvidos em duas etapas, utilizando-se as dependências e instalações da Embrapa - Agroindústria Tropical, em Fortaleza, CE, com os seguintes objetivos: avaliar quanto aos aspectos físicos, físico-químicos, químicos e bioquímicos de pedúnculos de cajueiro anão precoce CCP-76 durante o desenvolvimento e maturação; caracterizar quantitativa e qualitativamente as alterações nos constituintes da parede celular do pedúnculo associadas aos processos de desenvolvimento e maturação, e verificar o efeito da aplicação pós-colheita de cálcio, em diferentes concentrações, sobre as características físicas, físico-químicas, químicas e bioquímicas dos pedúnculos submetidos a armazenamento refrigerado sob atmosfera modificada. Os cajus utilizados neste trabalho, foram obtidos na área comercial de clones de cajueiro anão precoce instalada na Empresa Mossoró Agro-industrial S.A. O clone selecionado para este estudo foi o CCP-76 por ser o mais cultivado para produção de pedúnculos para comercialização in natura. As colheitas foram feitas em junho e agosto de 1997 para os experimentos 1 e 2 respectivamente, e em novembro de 1998 para o experimento 3. Os cajus, depois de colhidos, foram imediatamente transportados para o laboratório, onde se deu início aos estudos conforme o experimento em questão. Para os experimentos 1 e 2, os cajus foram selecionados em sete estádios de desenvolvimento e maturação de acordo com a coloração externa do pedúnculo e da castanha: 1. verde com castanha verde; 2. verde com castanha madura e seca; 3. verde claro; 4. Início de coloração amarela; 5. Amarelo com início de cor laranja; 6. laranja claro e 7. laranja escuro. No primeiro experimento, foram realizadas análises físicas, físico-químicas, químicas e bioquímicas dos pedúnculos: peso total (castanha + pedúnculo) peso do pedúnculo e o da castanha, diâmetros e comprimento, firmeza, clorofilas, carotenóides, antocianinas, pH, sólidos solúveis, acidez, vitamina C, cálcio, amido, açúcares, compostos fenólicos, pectinas, atividade das enzimas poligalacturonase, pectinametilesterase, polifenoloxidase e peroxidase. No segundo experimento, a partir de material de parede celular extraído, foram realizadas as seguintes análises: celulose, hemicelulose, uronídeos totais, grau de esterificação de pectinas e cálcio ligado. No terceiro experimento, os cajus foram colhidos no estádio de maturação comercial (estádio 7) e submetidos a seleção, préresfriamento, desinfecção em água clorada, secagem ao ar, nova seleção e tratamento com CaCI2 a 0,5%, 1% e 2% com espalhante adesivo, sendo que a testemunha foi apenas em água contendo o espalhante. Após secagem ao ar, os cajus foram acondicionados em bandejas, as quais foram envolvidas em PVC armazenadas em câmara com temperatura de 5°C ± 1°C e umidade relativa de 88% ± 3%. A cada 5 dias, por um período de 25 dias, foram tomadas amostras para execução das seguintes análises: perda de peso, firmeza, senescência, antocianinas, pectinas, compostos fenólicos, vitamina C, pH, sólidos solúveis, acidez, açúcares solúveis, cálcio, atividades de pectinamestilesterase e poligalacturonase. A maior relação sólidos solúveis/acidez foi atingida no estádio 7, indicando que este é o ideal para a colheita de pedúnculos ocasião em que alcança sua máxima qualidade para o consumo. Os pedúnculos de caju apresentaram amaciamento acentuado durante o desenvolvimento e maturação, observando-se paralelamente redução no teor de pectina total e aumento na percentagem de solubilização. A firmeza dos pedúnculos apresentou correlação significativa e inversa com a solubilidade das pectinas e com a atividade das enzimas PME e PG. A solubilidade da pectina, por sua vez, mostrou correlação significativa e positiva com a atividade de ambas as enzimas, que se correlacionaram entre si positivamente. O ambiente refrigerado aliado a atmosfera modificada, pode ser usado com sucesso no retardamento do processo de senescência do pedúnculo de caju, uma vez que aumenta substancialmente sua vida pós-colheita sem causar injúrias fisiológicas por até 20 dias. Pedúnculos tratados com cálcio foram mais firmes do que os não tratados, sendo que a partir de 0,5% não se observou um aumento do efeito. Doses crescentes de cálcio proporcionaram teores médios de cálcio total, solúvel e insolúvel superiores aos da tetemunha. O tratamento com cálcio não inibiu a atividade da pectinametilesterase. Porém foi decisivo na atividade de poligalacturonase, uma vez que os pedúnculos não tratados obtiveram valores médios de atividade dessa enzima superiores aos tratados. / Three experiments were carried out in two stages, using the EMBRAPA (Tropical and Agricultural Industry) - plants and annexes in Fortaleza, CE aiming the following: to evaluate the physícal, physicochemical, chemical and biochemical characteristícs of cashew apples of the clone CCP-76 during maturation and developing stages; to characterize qualitative and quantitative changes in the cell wall contents of the cashew apples due to developing and maturation processes; and to verify the post harvest application effect of calcium under different concentrations on cashew apples. The physical, physicochemical, chemical and biochemical characteristics of cashew apples stored under refrigeration and modified atmosphere were studied. The cashew apples used for this work were obtained from the clone experimental areas of early dwarf cashew trees of Mossoró Agricultural Company S.A. The selected clone for this study was the CPP-76 due to be recommended for commercial planting in function of its production aspects and cashew apple quality for consumption in natura. The harvests were done in June and August 1997 for the 1st and 2nd experiments, respectively and in November 1998 for the 3rd experíment. The cashew apples, after being harvested were transported immediately to the laboratories, for the starting of the due experiment. For the experiments 1 and 2, the cashew apples were selected in seven developing and maturation stages according to the cashew apple size and skin externai color as the following: 1- green cashew apple and nut; 2- green cashew apple with ripen dry nut; 3- light green cashew apple, 4- yellowish, 5- onset of the orange color, 6- light orange color, 7- dark orange color. For the first experiment the following physical, physicochemical, chemical and biochemical analyses were realized: total weight (cashew apple + nut), nut weights, cashew apple weights, diameters and lengths, firmness, chlorophylls, carotenoids, anthocyanins, pH, total soluble solids, titratable acidity, vitamin C, calcium, starch, sugars, phenolic compounds, pectins, polygalacturonase, pectinmethylesterase, polyphenoloxidade e peroxidase activities. In the second experiment, the following analyses on the cell wall material extracted, were realized: cellulose, hemicellulose, total uronides, pectin esterification degree and bound calcium. For the third experiment, the cashew apples were harvested on the commercial maturation stage and submitted to a selection, pre-cooling, chlorinated water washing, air drying, new selection and treatment with CaCI2 0.5%, 1% and 2% with thickener being the testimony, water and thickener only. After air drying, the cashew apples were placed on trays, involved with PVC film and stored at 5°C ± 1°C and relative humidity 88% ± 3%. Samples were taken for analyses at each 5 days during a 25 day period and the following analyses carried out: weight loss, firmness, senescence, anthocyanins, pectins, tannins, vitamin C, pH, total soluble solids, titratable acidity, calcium, soluble sugars, polygalacturonase, pectinmethylesterase activities. The major ratio soluble solids/acidity was reached in the stage 7, indicating that stage as the ideal for cashew apple harvesting, occasion that the edible quality peak is reached. The cashew apples showed a sharp softness during the development and maturation in parallel to a decrease in total pectin levei and increase in soluble pectin/total pectin ratio. There was an inverse and significative correlation between cashew apples firmness and pectin solubility, PME and PG activities. On the other hand, pectin solubility showed a significative and positive correlation with the activity of both enzymes, which correlated, positively to each other. The refrigeration added to the modified atmosphere may be used with success to delay cashew apple senescence process once they increase substantially its post harvest shelf life without causing physiological damage up to 20 days of storage. The cashew apples treated with calcium showed better firmness than those without treatment did, although, under calcium concentration up to 0,5% that effect was not observed anymore. Increased calcium dosages gave mean levei of total, soluble and insoluble calcium higher than the testimony. The calcium treatment did not inhibit the pectinmethylesterase activity. However, calcium was decisive for polygalacturonase activity, once the cashew apples that did not receive calcium treatment, obtained mean values for that enzyme activity higher than those treated.
13

The role of flexibility on propulsive performance of flapping fins

Kancharala, Ashok Kumar 02 September 2015 (has links)
The versatility of the fish to adapt to diverse swimming requirements has attracted the attention of researchers in studying bioinspired propulsion for developing efficient underwater robotics. The tail/caudal fin is a major source of thrust generation and is believed that the fish modulates its fin stiffness to optimize the propulsive performance. Inspired by the stiffness modulation of fish fins, the objective of this research is to predict and evaluate the effect of flexibility on propulsive performance of flapping fins. The stiffness of the fins vary along their length and optimization studies have been performed to predict the stiffness profiles that maximize performance. Experiments performed on the real fish caudal fins to measure the stiffness variation along their length validate the theoretical optimal stiffness profiles and provide an insight about the evolution of fish fins for optimal performance. Along with the fin stiffness, the stiffness of the joint (caudal peduncle) connecting the fish body to the tail plays a major role in the generation of thrust. The numerical and experimental investigation has shown that there exists an optimal combination of fin and joint stiffness for each operating condition, thus providing the motivation for active stiffness control during locomotion to optimize efficiency. Inspired by nature's ability to modulate stiffness and shape for different operating conditions, an investigation has been carried out on active control of flapping foils for thrust tailoring using Macro Fiber Composites (MFCs). It has been observed that the performance can be enhanced by controlling the deformation, and distributed actuation along fin produces maximum performance through proper selection of the phase difference between heaving and voltage. Flapping fins produce forces which are oscillatory in nature causing center of mass (COM) oscillations of the attached bodies posing problems of control and maneuverability. Optimization studies have revealed that flexibility of the fin plays a major role in reducing the COM oscillations along with the other operating parameters. Based on these studies, the design principles and guidelines that control the performance have been proposed which aid in the development of aerial and underwater robotic vehicles. Additionally, these studies provide some insight in to how fish might modulate its stiffness based on the requirements. / Ph. D.
14

Behavioral effects of deep brain stimulation in the subthalamic nucleus in obsessive compulsive disorder

Antonsson, Rebecka January 2021 (has links)
Obsessive compulsive disorder (OCD) is one of the most disabling psychiatric disorder. About 10% of patients with OCD do not respond to pharmacological treatment. However, deep brain stimulation (DBS) has advanced as an alternative treatment. In 2002, two patients who suffered from co-morbidity of Parkinson’s disease (PD) and OCD were treated with DBS for their PD, with DBS-electrodes placed in the subthalamic nucleus (STN). Surprisingly, not only PD symptoms but also OCD symptoms were improved. This was the first time that patients with OCD were treated with DBS in STN and it was found to markedly improve their symptoms. When performing DBS in patients with OCD, as well as for treating PD, several side-effectshave been observed. The side-effects can be both physical and psychological. In this project,the aim is to investigate the efficiency and side-effects of DBS in OCD, correlated with the position of the electrode in, or near, the STN. To address the aim, 10 published reports were analysed. It was found that all electrode positions reported resulted in great improvement of OCD symptoms. In fact, 88% of patients had significant improvement. There was no clear correlation between position of the electrode and number or type of side-effect. However, there was a trend that patients with the electrode placed in associative/limbic STN suffered from more side-effects. In conclusion, this project demonstrates that there might be a correlation between target for electrode stimulation and side-effects. It would be interesting analyse this closer, including additional electrode target areas, but also consider other possible explanations for the variety of side-effects caused by DBS for OCD.

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