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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.
221

Desenvolvimento e uso de marcadores SSR E DArT para estudos de diversidade genética em macadâmia (Macadamia integrifolia) / Development and use of SSR and DArT genetic markers to study genetic diversity in macadamia (Macadamia integrifolia)

Graciela da Rocha Sobierajski 24 May 2012 (has links)
A macadâmia (Macadamia integrifolia Maiden & Betche) é uma nogueira arbórea originária das florestas tropicais australianas. Sua distribuição natural ocorre por quase toda a costa leste da Austrália. No Brasil, foi introduzida em 1931, mas sua expansão aconteceu a partir da década de 70. As variedades comerciais são originadas de duas espécies, Macadamia integrifolia e M. tetraphylla, e seus híbridos. As informações sobre pedigree são geralmente incompletas e a identificação das variedades algumas vezes não é clara. O uso de técnicas moleculares auxilia em diversas fases dos programas de melhoramento, inclusive na caracterização do material genético e seleção de parentais envolvidos nos cruzamentos. A partir do uso de técnicas moleculares (microssatélites e diversity array technology), as 28 variedades que compõe o germoplasma brasileiro foram genotipadas com a finalidade de investigar a estrutura e a divergência genética entre estas. Foram utilizados 29 primers flanqueadores de locos microssatélites e 462 marcas de diversity array technology. A análise pelo programa Structure apresentou a formação de duas subpopulações: uma com a maioria das variedades desenvolvidas no Havaí/USA e Brasil, e outra composta pelas variedades desenvolvidas na Austrália e três variedades brasileiras. A análise da diversidade genética detectou valores medianos de heterozigosidade para o conjunto de variedades ( = 0,46 e = 0,43), com indicação de um pequeno excesso de homozigoto em relação ao esperado sob Equilíbrio de Hardy-Weinberg. A estimativa do índice de fixação (F = 0,067) para o conjunto de subpopulações apresentou grande variação, porém na média, foi baixo e não diferente de zero. Os resultados também mostram que a maior parte da diversidade genética do germoplasma está dentro de subpopulações ( q = 0,041). O índice de fixação devido ao sistema reprodutivo também variou entre os locos analisados, mas na média foi igualmente baixo e não diferente de zero ( f = 0,027). Os valores das Distâncias de Jaccard variaram entre 0,00 e 0,787 enquanto que as Distâncias de Roger Modificada variaram entre 0,227 e 0,671. O dendrograma UPGMA formado pelas Distâncias de Jaccard formou três grupos enquanto que pelas Distâncias de Roger Modificada formou dois grupos, sendo possível distinguir somente o grupo externo formado pelas duas espécies de grevílea. A falta de divergência entre alguns pares de variedades foi inesperada, assim como o não agrupamento entre variedades identificadas com o mesmo nome ou que apresentam histórico de parentesco. Da mesma forma, as duas subpopulações discriminadas pelo programa Structure não formaram agrupamento específico em ambos os dendrogramas. Os resultados das análises dos Componentes Principais foram coerentes aos obtidos nos dendrogramas formando os mesmos agrupamentos. / Macadamia (Macadamia integrifolia Maiden and Betche) is a nut crop tree widespread across eastern Australia. Although has been introduced in Brazil in 1931, just in the past 20 years its cultivated area has expanded more significantly. Commercial varieties are originated from Macadamia integrifolia and M. tetraphylla, as well as its hybrids. The information on pedigree is generally incomplete and the identification of varieties is sometimes not so clear. Molecular techniques could provide genetic information useful for breeding programs, such as, the kinship (relatedness) between individuals. Molecular techniques (microsatellites and diversity array technology) was used to genotype all 28 varieties that composes Brazils germoplasma with the purpose to investigate the structure and the genetic divergence between these varieties. Twenty nine microsatellites locus and 462 markers of diversity array was used. Analysis using the Structure software showed evidence of two subpopulations: one with the majority of the varieties developed in the Hawaii/USA and Brazil, and another with varieties developed in Australia and three in Brazil. The analysis of genetic diversity detected medium values of heterozigosis ( = 0.46 and = 0.43), with indication of a small excess of homozygotes in relation the expected value under Hardy- Weinberg equilibrium. The estimate of inbreeding coefficient showed great variation (from - 0.522 to 0.558), however in the average (F = 0.067) it was low and statistically not different from zero. The results also showed that most of the genetic diversity is within subpopulations ( q = 0.041). The inbreeding due to the reproductive system varied between analyzed loci, but on average it was low and statistically not different from zero ( f = 0.027). Values of Jaccard distances ranged from 0 to 0.787, whereas the modified Rogers distances ranged from 0.227 to 0.671. UPGMA Cluster analysis from Jaccard distances formed three groups, whereas modified Rogers distances of formed two groups. In the latter, it is possible to distinguish only the external group formed by the two species from Grevilea spp. For some varieties that we expected to be clustered together were unexpected assigned to different clusters. On the other hand, for some varieties that we expected to be placed in different clusters were unexpected clustered together. Unexpected, the two subpopulations discriminated in the analysis (Structure) did not form specific groups when using both Jaccard and modified Rogers distances. The results of Principal Coordinate Analysis were coherent with the UPGMA analyses.
222

Zoneamento agroclimático da Jatropha curcas L. como subsídio ao desenvolvimento da cultura no Brasil visando à produção de biodiesel / Agroclimatic zoning of Jatropha curcas L. as a subside for the crop development in Brazil aiming the biodiesel production

Eliane Seiko Maffi Yamada 29 April 2011 (has links)
No Brasil as pesquisas com Jatropha curcas L. foram impulsionadas a partir do marco regulatório do Programa Nacional de Produção e Uso do Biodiesel de 2004, em virtude da necessidade de substituição de matéria prima para fins energéticos. Por ser uma cultura recente no Brasil, ainda não existem pesquisas que definam a sua viabilidade e o sistema de cultivo mais adequado, apesar de muito se divulgar sobre a planta e suas potencialidades em regiões com grandes períodos de seca. Deste modo, o presente trabalho teve por objetivo caracterizar agroclimaticamente o Centro de Origem da jatropha para definição dos critérios de aptidão e elaboração do zoneamento agroclimático nas regiões brasileiras de maior estímulo ao plantio da cultura. Para tanto, foram levantados dados meteorológicos normais do Centro de Origem, no México e na Guatemala, o que permitiu a caracterização agroclimática dessas regiões e a definição das variáveis que mais afetam a cultura: temperatura do ar (Ta); deficiência hídrica (DEF); e excedente hídrico (EXC). A faixa de Ta apta para a jatropha está entre 23 e 27°C, sendo que as faixas entre 15 e 22,9°C e entre 27,1 a 2 8°C são classificadas como marginais por deficiência e excesso térmico, respectivamente. Abaixo de 15°C e acima de 28°C, as condições de inaptidão. Para o DEF, a aptidão ocorre para valores abaixo de 360 mm; enquanto entre 361 e 720 mm às áreas são consideradas marginais e acima de 720 mm inaptas. A faixa apta estabelecida para o EXC situa-se até 1200 mm, marginal entre 1201 e 2400 e inapta acima de 2400 mm. Os critérios definidos subsidiaram a elaboração do zoneamento agroclimático para a região Nordeste e para os estado do Tocantins, Goiás e Minas Gerais. Para a elaboração do zoneamento agroclimático da jatropha, os dados de temperatura e precipitação foram obtidos junto ao INMET e à ANA e empregados na confecção dos balanços hídricos normais. Os valores resultantes desses balanços, como evapotranspiração potencial (ETP) e real (ETR), DEF e EXC, compuseram a análise para espacialização a fim de se obter a variabilidade temporal e espacial dessas variáveis. A interpolação dos dados foi feita empregando-se o método da regressão linear múltipla, para estimativa espacial das variáveis agroclimáticas, e o da krigagem ordinária, para interpolação dos erros das estimativas. Os mapas gerados de Ta, DEF e EXC foram cruzados para obtenção dos mapas finais do zoneamento agroclimático para as regiões selecionadas. A partir dos mapas do zoneamento pode-se concluir que apenas 22,65% da região NE encontra-se como apta ao cultivo da jatropha, sendo as demais áreas classificada como marginal por deficiência hídrica (50,31%), marginal por excesso térmico e deficiência hídrica (11,79%) e inaptas (14,73%). Os estados de GO e TO apresentam a maior porcentagem de áreas aptas (47,78%), seguidas pelas áreas marginais por excesso térmico e deficiência hídrica (28,08%), marginais por deficiência hídrica (14,43%), e inaptas (9,37%). O estado de MG possui 33,91% de áreas aptas, 32,14% de áreas marginais por deficiência hídrica, 32,61% de áreas marginais por deficiência térmica e apenas 0,24% das áreas inaptas. A análise de risco, conduzida para o estado do TO, permitiu comprovar as chances de sucesso da cultura e confirmar que o zoneamento agroclimático para jatropha foi viável para estabelecer as áreas de maior favorabilidade ao cultivo dessa espécie. / In Brazil the researches with Jatropha curcas L. were stimulated by the regulatory mark of the National Program of Production and Use of Biodiesel of 2004, considering the necessity of changing the raw material for energetic purposes. As jatropha is a recent crop in Brazil, the researches for defining its feasibility and the best crop system are not yet available, even considering the promises about this plant as of high potential for regions with long drought periods. Based on that, the present study had as objectives to characterize the climate of the jatropha Center of Origin for defining the criteria for crop feasibility and for agroclimatic crop zoning in the Brazilian regions considered of high potentiality for the crop. For such purposes, climate data from de Center of Origin, in Mexico and Guatemala, were obtained and used for agroclimatic characterization and definition of the more relevant climatic variables for the crop: annual temperature (Ta); water deficiency (WD); and water surplus (WS). The range of Ta considered as feasible for jatropha was between 23 and 27oC; whereas between 15 and 22.9oC and between 27.1 and 28oC they were considered marginal, with limitations due to thermal deficiency and excess, respectively. Below 15oC and above 28oC, the conditions were considered unfeasible. For WD, the feasibility was considered for values below 360 mm. Values between 361 and 720 mm were considered marginal by water deficiency and above 720 mm unfeasible. The feasible condition for WS was admitted for values below 1200 mm; whereas marginality was considered for values between 1201 and 2400 mm. When the WS is above 2400 mm, the conditions are unfeasible. These criteria subsidized the elaboration of the jatropha crop zoning for the following Brazilian regions: Northeast region and states of Goiás, Tocantins, and Minas Gerais. For the confection of the crop zoning, climatic data from INMET and ANA were obtained and organized to calculate the normal climatological water balance. The outputs of the normal water balance, as potential (PET) and actual (AET) evapotranspiration, WD, and WS, were spacialized aiming to recognize the temporal and spatial variability of them. The interpolation of these variables was done base on the multiple linear regression method, associated to the ordinary kriging interpolation of the errors. The agroclimatic maps obtained for Ta, WD, and WS were crossed for obtaining the final agroclimatic crop zoning maps for the selected regions. Based on these maps, it was detected that only 22.65% of the areas in the NE region are feasible for jatropha. The other areas of the region are classified as marginal by water deficiency (50.31%), marginal by water deficiency and thermal excess (11.79%), and unfeasible (14.73%). In the states of Goiás and Tocantins the majority of the areas (47.78%) is classified as feasible, followed by 28.08% of the areas considered as marginal by water deficiency and thermal excess, 14.43% as marginal by water deficiency, and 9.37% as unfeasible. In Minas Gerais, 33.91% of the areas of the state are feasible, 32.14% are marginal by water deficiency, 32.61% are marginal by thermal deficiency, and only 0.24% are unfeasible. The analysis of climatic risk, conducted for Tocantins state, allowed to identify with more details where the jatropha crop can be successful and also proved that the agroclimatic crop zoning for jatropha was able to establish the areas of high favorability for growing this crop.
223

Análise da viabilidade do uso de cinzas agroindustriais em matrizes cimentícias: estudo de caso da cinza da casca da castanha de caju / Feasibility analysis of using agroindustrial ashes in cementitious materials: case study of ash of the rind of the cashew nut

Sofia Araújo Lima 27 May 2008 (has links)
Atualmente, o aproveitamento de resíduos na construção civil tem sido estimulado devido essa atividade ser um dos maiores consumidores de materiais naturais em seus processos e produtos. As cinzas agroindustriais ocupam lugar de destaque dentre os resíduos com possibilidades de aplicação em materiais cimentícios, pois algumas, como a cinza da casca do arroz, apresentam propriedades pozolânicas, contribuindo para a redução do consumo de cimento Portland. Nesse sentido, esta pesquisa teve como objetivo principal a avaliação da viabilidade técnica do uso de cinza agroindustriais em matrizes de cimento Portland, tendo como estudo de caso a cinza da casca da castanha de caju (CCCC). As cascas das castanhas de caju, resíduos da produção das castanhas, são incorporadas novamente ao processo, e, nas caldeiras, irão gerar calor para a decorticação de novas castanhas. A CCCC é o resíduo colhido no fundo da grelha das caldeiras, resultante da queima das cascas de castanhas. Atualmente, esse resíduo é utilizado como adubo em plantações de caju, sendo uma pequena parte destinada à aterros sanitários comuns. Foram realizados ensaios para avaliar a composição físico-química da CCCC; analisar o potencial pozolânico; analisar a retração por secagem e da profundidade de carbonatação de argamassas confeccionados com CCCC; e determinar a capacidade de estabilização/solidificação da CCCC pela matriz cimentícia. A partir dos resultados, pode-se apontar como características principais da CCCC: i) não apresentar potencial pozolânico; ii) favorecer a incorporação de ar em matrizes cimentícias; iii) ocasionar solubilidade de metais pesados e Fenol quando no estado in natura; iv) contribuir para o aumento da retração por secagem e da carbonatação em argamassas; v) liberar Cromo e Sódio mesmo quando estabilizada/solidificada em pastas em teores de até 10% de substituição. Por essas considerações, a CCCC não apresentou viabilidade técnica para uso em matrizes cimentícias. / Nowadays, the use of wastes on civil building has been stimulated for it to be one of most consumers of raw materials in their processes and products. The agroindustrial ashes have a prominent place among the wastes with possibilities of application in cementitious materials, because some ashes, such rice husk ash, have pozzolanic activity, and they contribute to reduce the Portland cement consumption. This work aimed to study the evaluation of technical feasibility of the agroindustrial ashes for use in Portland cement matrices, using the ash of the rind of the cashew nut (ARCN) as case study. The rinds of cashew nut (wastes of nuts\' production) are burned again during the heating process, and in boilers, they will generate heat for shelling other nuts. The ARCN is the waste collected from the boiler grid, resulted from burning of the rind of nuts. This waste is used as compostes in plantings of cashew and a little part of it is dumped in landfill sites. Tests were made for evaluation of physico-chemical composition of ARCN; for analyse of pozzolanic activity; for analyse of drying shrinkage and carbonation in mortars made with ARCN; and the analyse of the stabilization/solidification of ARCN in pastes. After the analyse of results, it may be pointed as main features of ARCN: i) not show pozzolanic activity; ii) to promote air entrainment in cementitious matrices; iii) to cause heavy metals and Phenol solubilization as in raw state; iv) to increase the drying shrinkage and carbonation in mortars; and, v) to let out Chrome and Sodium when stabilizated/solidificated in pastes in levels of replacement until 10%. For all these considerations, the ARCN haven\'t showed technical feasibility for use in cementitious matrices.
224

EFEITOS BENÉFICOS DO EXTRATO DAS CASCAS DE NOZ PECÃ (Carya illinoensis) SOBRE PARÂMETROS BIOQUÍMICOS E COMPORTAMENTAIS DE CAMUNDONGOS EXPOSTOS AO FUMO PASSIVO / BENEFICIAL EFFECTS OF PECAN NUT SHELLS (Carya illinoensis) AGAINST BIOCHEMICAL AND BEHAVIORAL PARAMETERS OF MICE EXPOSED TO PASSIVE SMOKE

Reckziegel, Patrícia 28 January 2011 (has links)
Fundação de Amparo a Pesquisa no Estado do Rio Grande do Sul / Smoking is the second major reason of death worldwide, amounting 5 millions of deaths annually. The adverse effects of cigarette smoking are not limited to active smokers, but also to passive smokers, which comprise one third of worldwide adult population. Cigarette smoking contain nicotine and other addiction related compounds, as well as components that can generate oxidative stress (OS), an unbalance between oxidants and antioxidants of the body, probably responsible for the pathogenesis of smoke-related disorders. The shells of pecan nut (Carya illinoensis) are an industrial byproduct of low cost and high antioxidant potential, whose tea is popularly used as treatment for drug and smoking intoxications, however without scientific validation. Therefore, the present study investigated the possible protection of pecan nut shells aqueous extract (AE) against abstinence behavioral parameters and OS biochemical parameters in animals exposed to passive cigarette smoke. Swiss mice received drinking water or AE (25g/L), ad libitum, in the place of water during one week before and during 3 weeks of cigarette smoke exposure (6, 10 and 14 cigarettes/day each week, respectively), which occurred in a modified incubator. The environmental concentration of carbon monoxide and total suspended particulate matter in the incubator were 130ppm and 188mg/m3, respectively. Fifteen hours after the last cigarette smoke exposure, the animals were evaluated in the open-field test and in the marble burning test. Twenty hours after the last cigarette smoke exposure, the animals were anesthetized and euthanized by exsanguination (cardiac puncture), with collection of blood and removal of brain for biochemical analysis. Data were analyzed by one or two-way ANOVA, followed by Duncan s test when necessary. The protocol of cigarette smoke exposure increased total concentration of carbon dioxide in blood and the hematocrit, which are indirect biochemical markers of cigarette smoke exposure, and reduced the body weight gain of animals without altering fluid intake. In the open-field test, animals exposed to passive smoke showed increase in locomotor and exploratory activities, self-cleaning time and fecal pellets number, as well as in the number of beads hidden in the marble burning test, than the controls. The animals that received AE did not develop these behavioral changes, which indicate anxiety, characteristic related to smoking abstinence. In this study, the involvement of smoking with oxidative damages described in the literature was confirmed by increasing cerebral and erythrocyte lipid peroxidation, increasing in erythrocyte catalase (CAT) activity and decreasing in plasma ascorbic acid. The pecan shells AE was able to protect the mice exposed to cigarette smoke of the lipid peroxidation and decrease of plasma ascorbic acid levels. CAT activity remained high in erythrocytes and increased in brain of animals exposed to cigarette smoke and that received AE, possible as a compensatory mechanism to eliminate excess of reactive oxygen species (ROS) induced by cigarette smoke. It is hypothesized that these biochemical results are in large part due the high antioxidant potential of AE, confirmed by in vitro assays of ABTS (2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid)) and DPPH (2,2- diphenyl-1-picrylhydrazyl) and by measuring of total phenolic compounds and condensed tannins levels. By Pearson correlation, were observed positive correlations between behavioral parameters evaluated and erythrocyte lipid peroxidation, confirming the involvement of anxiety and OS. The results presented here show the protective effect of pecan nut shells AE on anxiety-like sings of cigarette withdrawal and on oxidative damages and altered antioxidant defenses induced by passive cigarette smoke in mice. Moreover, the popular use of pecan nut shell extract against cigarette smoke was confirmed. It is believed that this industrial byproduct can be considered in the treatment of smoking, increasing the poor therapeutic armamentarium currently employed for this end. Further studies elucidating the components present in this extract, as well as neural mechanisms related to these results are needed. / O tabagismo representa a segunda maior causa de mortes no mundo, sendo responsável por 5 milhões de mortes anuais. Não apenas os fumantes ativos estão sujeitos aos efeitos danosos do cigarro, mas também os fumantes passivos, que compreendem um terço da população adulta mundial. A fumaça do cigarro contém nicotina e outros compostos relacionados à adição, bem como constituintes capazes de gerar estresse oxidativo (EO), um desequilíbrio entre os oxidantes e as defesas antioxidantes do organismo, possivelmente responsável pelos efeitos danosos do cigarro sobre o organismo. A casca da noz pecã (Carya illinoensis) é um subproduto industrial de baixo custo e elevado poder antioxidante, cujo chá é utilizado popularmente para tratar intoxicações medicamentosas e resultantes do tabagismo. Porém, até o momento, esse emprego não apresenta validação científica. Em vista disso, o presente estudo investigou a possível atividade protetora do extrato aquoso bruto (EAB) da casca da noz pecã sobre parâmetros comportamentais de abstinência e parâmetros bioquímicos de EO em animais expostos ao fumo passivo. Camundongos Swiss receberam água potável ou EAB (25g/L), ad libitum, no lugar da água de beber, uma semana antes e durante toda exposição à fumaça do cigarro, a qual teve duração de 3 semanas (6, 10 e 14 cigarros/dia em cada semana, respectivamente) e ocorreu em incubadora modificada. A concentração ambiental de monóxido de carbono e material particulado total na incubadora foram 130ppm e 188mg/m3, respectivamente. Quinze horas após a última exposição ao fumo passivo os animais foram avaliados no teste do campo aberto e no teste de esconder esferas. Vinte horas após a última exposição ao fumo passivo os animais foram anestesiados e eutanasiados por exsanguinação (punção cardíaca), com coleta de sangue e retirada do cérebro para as análises bioquímicas. Os dados foram analisados por ANOVA de uma ou duas vias, seguido pelo teste de Duncan quando necessário. O protocolo de exposição ao fumo passivo elevou a concentração total de dióxido de carbono sanguíneo e o hematócrito, os quais são marcadores indiretos de exposição à fumaça do cigarro, bem como reduziu o ganho de peso dos animais sem alterar o consumo de líquidos. No campo aberto, animais expostos ao fumo passivo apresentaram aumento da atividade locomotora e exploratória, do tempo de auto-limpeza e do número de bolos fecais, bem como mostraram aumento do número de esferas escondidas no teste de esconder esferas em relação aos controles. Os animais que receberam EAB não desenvolveram essas modificações comportamentais, as quais indicam ansiedade, característica essa relacionada à abstinência ao cigarro. Neste estudo, o envolvimento do tabagismo com os danos oxidativos já descritos na literatura foi confirmado através do aumento da peroxidação lipídica cerebral e eritrocitária, aumento da atividade da catalase (CAT) eritrocitária e redução das concentrações plasmáticas de ácido ascórbico. O EAB da casca de noz pecã protegeu os animais expostos ao fumo passivo da peroxidação lipídica e da redução dos níveis plasmáticos de ácido ascórbico. A atividade da CAT permaneceu aumentada nos eritrócitos e elevou-se no cérebro dos animais expostos ao fumo passivo e tratados com EAB em relação aos controles, possivelmente pela indução de mecanismos compensatórios que visam eliminar o excesso de espécies reativas de oxigênio (EROs) induzido pelo cigarro. Hipotetizou-se que esses resultados bioquímicos devem-se, em grande parte, ao elevado potencial antioxidante do EAB, confirmado através dos testes in vitro do ABTS (2,2´- azinobis(3-etilbenzotiazolina-6-ácido sulfônico) e do DPPH (2,2-difenil-1-picrilhidrazil) e pela dosagem de compostos fenólicos totais e taninos condensados. Através de correlação de Pearson, foram observadas correlações positivas entre os parâmetros comportamentais e a peroxidação lipídica eritrocitária, confirmando o envolvimento da ansiedade com o EO. Os resultados apresentados aqui evidenciam os efeitos protetores do EAB das cascas da noz pecã sobre os sinais de ansiedade durante abstinência e sobre danos oxidativos e defesas antioxidantes alterados pelo fumo passivo em camundongos. Ademais, confirma-se o uso popular do extrato das cascas de noz pecã frente danos induzidos pelo cigarro e entende-se que esse subproduto da indústria pode ser considerado no tratamento do tabagismo, o que aumentaria o carente arsenal terapêutico empregado atualmente no tratamento do tabagismo. Maiores estudos elucidando os componentes presentes nesse extrato, bem como os mecanismos neurais relacionados aos resultados encontrados são necessários.
225

Trous noirs en supergravité N = 2 / Black holes in N = 2 supergravity

Erbin, Harold 23 September 2015 (has links)
La solution des équations d'Einstein–Maxwell décrivant le trou noir le plus général a été découverte par Plebański et Demiański en 1976. Cette thèse accomplit plusieurs étapes en vue d'intégrer une généralisation de cette solution en supergravité jaugée N = 2. Le contenu bosonique de cette dernière comprend la métrique assortie de champs de jauge et de deux types de champs scalaires (appelés scalaires-vecteurs et hyperscalaires); cela implique qu'il est beaucoup plus compliqué de trouver une solution générale et l'on doit se restreindre à des classes particulières de solutions ou bien utiliser des algorithmes pour générer des solutions.Dans la première partie de cette thèse nous approchons ce problème grâce à la première stratégie en nous restreignant aux solutions BPS.Dans un premier temps nous étudions les jaugeages abéliens qui impliquent les hyperscalaires afin de comprendre quelles sont les conditions nécessaires pour obtenir des vides N = 2 adS4 ainsi que des géométries de proche-horizon associées à des trous noirs statiques.Par la suite nous décrivons une solution générale et analytique pour des trous noirs (extrémaux) 1/4-BPS qui possèdent une masse, une charge de NUT, des charges dyoniques et des champs scalaires non-triviaux dans le contexte de la supergravité N = 2 jaugée à la Fayet–Iliopoulos.Dans la seconde partie nous obtenons une extension de l'algorithme de Janis-Newman afin de prendre en compte tous les champs bosoniques de spin inférieur à 2, les horizons topologiques et le cas des autres dimensions.Ainsi cela met à disposition tous les outils nécessaires pour appliquer cet algorithme à la supergravité (jaugée ou non). / The most general black hole solution of Einstein–Maxwell theory has been discovered by Plebański and Demiański in 1976.This thesis provides several steps towards generalizing this solution by embedding it into N = 2 gauged supergravity.The (bosonic fields of the) latter consists in the metric together with gauge fields and two kinds of scalar fields (vector scalars and hyperscalars); as a consequence finding a general solution is involved and one needs to focus on specific subclasses of solutions or to rely on solution generating algorithms. In the first part of the thesis we approach the problem using the first strategy: we restrict our attention to BPS solutions, relying on a symplectic covariant formalism. First we study the possible Abelian gaugings involving the hyperscalars in order to understand which are the necessary conditions for obtaining N = 2 adS4 vacua and near-horizon geometries associated to the asymptotics of static black holes.A preliminary step is to obtain covariant expressions for the Killing vectors of symmetric special quaternionic-Kähler manifolds. Then we describe a general analytic solutions for 1/4-BPS (extremal) black holes with mass, NUT, dyonic charges and running scalars in N = 2 Fayet–Iliopoulos gauged supergravity with a symmetric very special Kähler manifold. In the second part we provide an extension of the Janis–Newman algorithm to all bosonic fields with spin less than 2, to topological horizons and to other dimensions. This provides all the necessary tools for applying this solution generating algorithm to (un)gauged supergravity, and interesting connections with the N = 2 supergravity theory are unravelled.
226

Zkoušky řezivosti VBD při soustružení konstrukční kalené oceli / Cutting Tests of Insert for Turning Structural Hardened Steel

Šolc, Michal January 2020 (has links)
The thesis deals with the wear of replaceable inserts during the turning of structural hardened steel. The theoretical part describes a brief characteristic of turning technology, force loading on tools and tools used in turning. Moreover, it contains an analysis of the chemical composition of the machined material, its microstructure and microhardness. Machines and equipment used for the experiment and their specifications. The experimental part of the thesis describes the method of measuring and evaluating of tool wear, followed by the cutting tests themselves, documenting of the result and their evaluation. The conclusion of the thesis is the processing of measured data, the evaluation of achieved results and the proposal of further steps to improve the process.
227

Elektromechanická alternativa hydraulické lineární tahové jednotky / Electromechanical alternative of linear hydraulic tractive unit

Hammer, Jaroslav January 2008 (has links)
In this diploma thesis is accomplished description of existing condition of decorating linear tractive unit. Analysis of safety requirements for linear tractive unit is also accomplished. Eligible construction concept of frame of electromechanical linear tractive unit is chosen. Selection and calculation of ball screw and nut is made also with draft of its eligible support . Choose of eligible engine and clutch for gearing of engine torque from engine to the ball screw is done too. Further is designed eligible concept of gearing of the rotary motion of ball screw to straight motion of bottom pulley block, which now interacting with upper firm pulley block provides lifting of tensile rod with coulisse.
228

Srovnání MKP modelů spojů / Comparision of FEM models of joints

Hlaváč, Martin January 2011 (has links)
This thesis deals with the comparison of alternative models of the simplified joints used in the FEM models of complex models with detailed joint details. This is essentially a screw connection with dowel bolt and standard bolt, weld connection "T" and overlap weld connection. Individual connections are compared in the simulation results of matching models.
229

The evaluation of the nutritive value of Baobab seed cake and Macadamia oil cake as feed for ruminants

Mikasi, Masiza Samuel 21 September 2018 (has links)
PhD (AGR) (Animal Science) / Department of Animal Science / Horticultural by-products such as seed and nut oil residues have the potential to replace conventional protein and energy sources in diets for ruminants. The objective of the study was to evaluate the nutritive value of Macadamia oil cake and Baobab seed cake as nutrient supplements for feedlot animals. Several experiments were carried-out to evaluate the nutritive value of Macadamia oil cake and Baobab seed cake as feed for ruminants. The nutrient composition of the cakes were determined using both proximate and modern methods of analysis of feeds and a t-test was used to compare the means of Macadamia oil cake and Baobab seed cake. The in sacco technique was used to determine the rumen degradability parameters of dry matter, crude protein and Amino acids of the cakes. This experiment was conducted using a completely randomized design. A three step-in vitro technique was used to conduct a post ruminal digestibility trial and the study was arranged in a completely randomized design. An apparent digestibility trial was conducted using metabolism cages and fecal bags to avoid the mixing of urine and faeces and the experiment was carried out as a completely randomized design arranged in a 2 x 2 factorial. A growth trial was conducted using a completely randomized block design arranged in a 2x2 factorial with two protein supplements and two inclusion levels as factors and blocked by sex of the lambs. The two cakes had similar (P>0.05) dry matter, fat, hemicellulose and gross energy contents. Baobab seed cake had significantly (P<0.05) higher ash, crude protein, acid detergent lignin and nitrogen free extract than macadamia oil cake. Macadamia oil cake had significantly (P<0.05) higher crude fiber, acid detergent fiber, neutral detergent fiber and cellulose concentrations. Baobab seed cake had significantly (P<0.05) higher calcium, magnesium, potassium, phosphorus (macroelements), zinc, and copper than macadamia oil cake. Macadamia oil cake was significantly (P<0.05) higher in manganese and iron contents than Baobab seed cake. Sodium content was not significantly (P>0.05) different between the two cakes. Baobab seed cake had more (Tryptophan, Cysteine, Arginine, Aspartic acid, Glutamic acid, Valine, Phenylalanine, Isoleucine, Leucine) Amino acids which were significantly (P<0.05) higher in quantity than macadamia oil cake with the two cakes having similar (P>0.05) remaining Amino acids contents. Generally Macadamia oil cake had more (P<0.05) saturated and mono-unsaturated fatty acids than Baobab seed cake whereas Baobab seed cake had more (P<0.05) poly-unsaturated fatty acids. v The in sacco rumen degradability characteristics of baobab seed cake and macadamia oil cake were estimated for dry matter and crude protein of the cakes. Macadamia oil cake had significantly (P<0.01) higher a value for dry matter than boabab seed cake. Baoaba seed cake had significantly (P<0.01) higher a value for crude protein than macadamia oil cake. the b, c, and a+b values for dry matter of both Baobab seed cake and Macadamia oil cake were not significantly (P>0.05) different form each other. However, the potential degradability (a+b) value for crude protein of baobab seed cake was significantly (P<0.01) higher than that of macadamia oil cake. The b and c constants of the two cakes for crude protein were not significantly (P>0.05) different from each other. The ED (Effective degradability) values calculated at three outflow rates (0.02, 0.05, 0.08) were estimated for dry matter and crude protein of Baobab seed cake and macadamia oil cake. The ED of the two cakes calculated at 0.02 outflow rate did not significantly (P>0.05) differ from each other. However, baobab seed cake had significantly (P<0.05) higher ED value at outflow rate of 0.05 whereas macadamia oil cake had significantly (P<0.05) higher ED value calculated at outflow rate of 0.08. The ED values of baobab seed cake for crude protein calculated at the three outflow rate were significantly (P<0.01) higher than those of macadamia oil cake. The two cakes did not significantly (P>0.05) differ in dry matter ruminal degradability but baobab seed cake had significantly (P<0.05) higher ruminal crude protein disappearance from 16 to 72 hours of incubation than macadamia oil cake. The in situ Amino acid degradation was determined on 0, 12, 16, 24, and 48 hour of ruminal incubation of the cakes’ samples and generally they were significant (P<0.05) differences for both cakes according to different incubation periods. The 3-step in vitro digestibility trial revealed that baobab seed cake had significantly (P<0.05) higher dry matter, crude protein and Amino acids digestibility values than macadamia oil cake. Apparent digestibility study revealed that nutrient intake, faecal and urine outputs, and digestibility of nutrients were not significantly (P>0.05) different between baobab seed cake and macadamia oil cake. However, lambs on 10% macadamia cake having retained significantly (P<0.05) more nitrogen than the lambs on 15% macadamia oil cake, 10% and 15% baobab seed cakes diets. However, the inclusion of either baobab seed cake or macadamia oil cake at 10% or 15% in the diets of lambs did not significantly (P>0.05) affect the DOMR, microbial protein yield and purine derivates output. For the growth trial the lambs were offered four diets formulated to contain 10% MOC (control), 15% MOC, 10 BSC and 15% BSC. The inclusion of 15% MOC and 10% BSC in the diets of lambs did not significantly (P>0.05) affect their final body weight, total weight gain, average daily feed intake, average daily weight gain, warm and cold carcass masses between these two vi groups. The inclusion of 10% MOC and 15% BSC in the diets of lambs did not significantly affect average daily feed intake and animal performance between these two groups. However, lambs on 10% MOC and 15% BSC had significantly (P<0.05) higher average daily feed intake and animal performance compared to lambs on 15% MOC diet. The feed conversion efficiency and of the lambs in the four diets were not significantly (P>0.05) different. The dressing percentage, carcass length, neck weight, fat thickness, body weight thickness and rib eye area of the carcasses of lambs in this trial did not differ significantly (P>0.05) except for spleen and skin with lambs on 10% BSC diets having the least skin weight and lambs on 10% MOC diet having heaver spleens. Generally BSC had higher (P<0.05) nutrient content than MOC. BSC and MOC were highly degradable in the rumen whereas BSC was higly digestible post-ruminally compared to MOC. The diets of fattening lambs formulated to include 10% or 15% of BSC or MOC as protein supplements did not affect the apparent digestibility of the diets. Macadamia oil cake can be incomporated in the diet of finishing lambs as a protein supplement at 10% inclusion level without compromising the growth and carcass characteristics of the lambs. Baobab seed cake as a protein supplement can be included in the diet of finishing lambs at up to 15% inclusion level without deleteriously compromising on the growth and carcass characteristics of the animals. ______________________________________ / NRF
230

Development of strategies for the successful production of yogurt-like products from Tiger nut (Cyperus esculentus L) milk

Kizzie-Hayford, Nazir 02 March 2017 (has links)
Tiger nuts (Cyperus esculentus L) are recognized as a high potential, alternative source of food nutrients. However, there is limited scientific literature on the technological possibilities for developing value-added foods, such as fermented products from tiger nut milk. Therefore, strategies for producing and improving the properties of fermented tiger nut milk were investigated for generating lactose-free, nutritious yogurt-like products with acceptable sensory properties and a prolonged shelf life quality. A wet-milling procedure was standardized for extracting tiger nut milk from tiger nuts, and the effects of the extraction process on nutrient distribution, colour properties and colloidal stability of the milk were analyzed. Next, tiger nut milk was enriched with proteins and/or hydrocolloids and the impact of the additives on the physical properties of the milk were determined. Enriched tiger nut milk was fermented by using classical yogurt cultures and the obtained products were analyzed for the microbiological, physico-chemical and sensory characteristics. Additionally, effects of enriching tiger nut milk with microbial transglutaminase cross-linked proteins on the microbiological and physico-chemical properties were evaluated. Higher wet-milling intensity improved the nutrient composition, colloidal stability and colour of the milk. Enrichment of tiger nut milk with milk proteins and xanthan gum enhanced the viscosity and stability, and after fermentation, led to homogenous gel-like products with superior microbiological, physico-chemical and different sensory properties compared to the fermented plain tiger nut milk. Microbial transglutaminase cross-linked proteins improved the physical characteristics of the fermented product, especially during storage. This product would be relevant in many developing countries with high prevalence of lactose intolerance, limited access to nutritious food but show a high distribution of tiger nut vegetation.:1. Introduction and aim 1 2. Literature review 4 2.1 Tiger nut, origin, nutritional value and food use 4 2.2 Tiger nut milk, preparation and nutrient composition 7 2.3 Colloidal characteristics of tiger nut milk 9 2.4 Factors accounting for the dispersion stability of tiger nut milk 10 2.5 Enhancing tiger nut milk stability 12 2.6 Properties of fermented tiger nut milk 17 2.7 Microbial transglutaminase and properties of fermented tiger nut milk 18 3. Methodology 21 3.1 Extraction and characterisation of tiger nut milk 21 3.1.1 Sample collection and preparation 21 3.1.2 Tiger nut milk extraction 21 3.1.3 Nutrient analysis of tiger nuts 22 3.1.4 Analysis of tiger nut products 23 3.1.5 Particle size distribution 24 3.1.6 Colloidal stability 25 3.1.7 Colour measurement 25 3.2 Stabilisation of tiger nut milk dispersion 26 3.2.1 Tiger nut milk preparation 26 3.2.2 Preparation of tiger nut milk enrichments 26 3.2.3 Gravitational stability of enriched tiger nut milk 27 3.2.4 Accelerated gravitational stability of enriched tiger nut milk 28 3.2.5 Viscosity of TNM mixtures 29 3.3 Extraction and characterisation of globular tiger nut proteins 29 3.3.1 Protein extraction and fractionation 29 3.3.2 Molecular mass of globular tiger nut proteins 31 3.3.3 Denaturation temperature of globular tiger nut proteins 32 3.3.4 Isoelectric point of globular tiger nut protein 33 3.4 Properties of fermented tiger nut milk enriched with proteins 34 3.4.1 Materials and Reagents 34 3.4.2 Preparation of plain and enriched tiger nut milk 34 3.4.3 Fermentation of plain and enriched tiger nut milk 35 3.4.4 Viable counts of starter cultures in fermented tiger nut milk systems 36 3.4.5 Chemical analysis of unfermented and fermented tiger nut milk 36 3.4.6 Physical analysis of fermented tiger nut milk products 37 3.4.7 Sensory analysis of fermented tiger nut milk products 38 3.5 Microbial transglutaminase and fermented tiger nut milk property 38 3.5.1 Preparation of plain and enriched tiger nut milk 38 3.5.2 Fermentation of plain and enriched tiger nut milk 39 3.5.3 Analysis of the enzymatically cross-linked proteins 39 3.5.4 Viable counts 40 3.5.5 pH and titratable acidity 40 3.5.6 Syneresis and viscosity 41 3.5.7 Colour of fermented tiger nut products 41 3.6 Statistical analysis 41 4. Results and discussion 43 4.1 Extraction and characteristics of tiger nut milk 43 4.1.1 Material recovery, mass transfer and yield of tiger nut solids 43 4.1.2 Nutrient composition of tiger nut products 45 4.1.3 Physical properties of tiger nut milk 48 4.1.3.1 Particle size distribution of extracted tiger nut milk 48 4.1.3.2 Colloidal stability of tiger nut milk 49 4.1.3.3 Colour stability of tiger nut milk 51 4.2 Stabilisation of tiger nut milk 53 4.2.1 Effects of enrichments on the stability of tiger nut milk 53 4.2.2 Effects of pH and temperature on the stability of enriched TNM 56 4.2.3 Effects of enrichments on the rheology of tiger nut milk 58 4.3 Tiger nut protein extraction and characterisation 60 4.3.1 Protein extraction and fractionation 60 4.3.2 Molecular mass of tiger nut protein 62 4.3.3 Thermal denaturation of tiger nut protein 63 4.3.4 Isoelectric point of tiger nut proteins 66 4.4 Properties of fermented tiger nut milk enriched with proteins 67 4.4.1 Acidification and gel formation during fermentation 67 4.4.2 Microbiological properties of fermented enriched tiger nut milk 70 4.4.3 Physico-chemical properties of fermented enriched tiger nut milk 71 4.4.4 Sensory properties of fermented tiger nut milk products 76 4.5 Microbial transglutaminase and fermented tiger nut milk property 77 4.5.1 Effects on tiger nut milk fermentation 77 4.5.2 Microbiological properties during storage of fermented product 81 4.5.3 Physico-chemical properties during storage of fermented product 83 4.5.4 Effects on colour of fermented tiger nut product 86 5. Conclusions and outlook 88 Bibliography 90 List of figures 111 List of tables 115 List of Publications 116 Poster and presentations 116 / Erdmandeln (Cyperus esculentus L) haben ein hohes Potential als alternative Quelle Lebensmittelinhaltsstoffen. Allerdings gibt es nur in begrenztem Ausmaß Literatur über technologische Möglichkeiten zur Entwicklung von Mehrwert-Lebensmitteln wie fermentierter Erdmandelmilch. Daher wurden Strategien zur Herstellung und Verbesserung der Eigenschaften von fermentierter Erdmandelmilch zur Erzeugung laktosefreier joghurtähnlicher Produkte mit akzeptablen sensorischen Eigenschaften untersucht. Für die Extraktion der Erdmandelmilch wurde ein Nassmahlverfahren standardisiert und der Einfluss des Verfahrens auf die Nährstoffverteilung, die Farbeigenschaften und die kolloidale Stabilität der Milch analysiert. Als nächstes wurde Erdmandelmilch mit Proteinen und/oder Hydrokolloiden angereichert, und der Einfluss der Additive auf die physikalischen Eigenschaften des Extrakts bestimmt. Angereicherte Erdmandelmilch wurde mit klassischen Joghurtkulturen fermentiert, und die mikrobiologischen, physikalisch-chemischen und sensorischen Eigenschaften der Produkte wurden untersucht. Zusätzlich wurden Effekte der Anreicherung von Erdmandelmilch mit enzymatisch vernetzten Proteinen auf die mikrobiologischen und physikalisch-chemischen Eigenschaften bewertet. Eine höhere Nassmahlintensität verbesserte die Nährstoffzusammensetzung, die kolloidale Stabilität und die Farbe der Milch. Die Anreicherung erhöhte die Viskosität und Stabilität und führte nach der Fermentation zu homogenen gelartigen Produkten mit verbesserten mikrobiologischen, physikalisch-chemischen und sensorischen Eigenschaften im Vergleich zur fermentierten Erdmandelmilch. Mikrobielle Transglutaminase-vernetzte Proteine verbesserten die physikalischen Eigenschaften des fermentierten Produkts, insbesondere während der Lagerung. Dieses Produkt wäre in vielen Entwicklungsländern mit hoher Prävalenz von Laktoseintoleranz und begrenztem Zugang zu nahrhaften Lebensmitteln als Alternative von Interesse.:1. Introduction and aim 1 2. Literature review 4 2.1 Tiger nut, origin, nutritional value and food use 4 2.2 Tiger nut milk, preparation and nutrient composition 7 2.3 Colloidal characteristics of tiger nut milk 9 2.4 Factors accounting for the dispersion stability of tiger nut milk 10 2.5 Enhancing tiger nut milk stability 12 2.6 Properties of fermented tiger nut milk 17 2.7 Microbial transglutaminase and properties of fermented tiger nut milk 18 3. Methodology 21 3.1 Extraction and characterisation of tiger nut milk 21 3.1.1 Sample collection and preparation 21 3.1.2 Tiger nut milk extraction 21 3.1.3 Nutrient analysis of tiger nuts 22 3.1.4 Analysis of tiger nut products 23 3.1.5 Particle size distribution 24 3.1.6 Colloidal stability 25 3.1.7 Colour measurement 25 3.2 Stabilisation of tiger nut milk dispersion 26 3.2.1 Tiger nut milk preparation 26 3.2.2 Preparation of tiger nut milk enrichments 26 3.2.3 Gravitational stability of enriched tiger nut milk 27 3.2.4 Accelerated gravitational stability of enriched tiger nut milk 28 3.2.5 Viscosity of TNM mixtures 29 3.3 Extraction and characterisation of globular tiger nut proteins 29 3.3.1 Protein extraction and fractionation 29 3.3.2 Molecular mass of globular tiger nut proteins 31 3.3.3 Denaturation temperature of globular tiger nut proteins 32 3.3.4 Isoelectric point of globular tiger nut protein 33 3.4 Properties of fermented tiger nut milk enriched with proteins 34 3.4.1 Materials and Reagents 34 3.4.2 Preparation of plain and enriched tiger nut milk 34 3.4.3 Fermentation of plain and enriched tiger nut milk 35 3.4.4 Viable counts of starter cultures in fermented tiger nut milk systems 36 3.4.5 Chemical analysis of unfermented and fermented tiger nut milk 36 3.4.6 Physical analysis of fermented tiger nut milk products 37 3.4.7 Sensory analysis of fermented tiger nut milk products 38 3.5 Microbial transglutaminase and fermented tiger nut milk property 38 3.5.1 Preparation of plain and enriched tiger nut milk 38 3.5.2 Fermentation of plain and enriched tiger nut milk 39 3.5.3 Analysis of the enzymatically cross-linked proteins 39 3.5.4 Viable counts 40 3.5.5 pH and titratable acidity 40 3.5.6 Syneresis and viscosity 41 3.5.7 Colour of fermented tiger nut products 41 3.6 Statistical analysis 41 4. Results and discussion 43 4.1 Extraction and characteristics of tiger nut milk 43 4.1.1 Material recovery, mass transfer and yield of tiger nut solids 43 4.1.2 Nutrient composition of tiger nut products 45 4.1.3 Physical properties of tiger nut milk 48 4.1.3.1 Particle size distribution of extracted tiger nut milk 48 4.1.3.2 Colloidal stability of tiger nut milk 49 4.1.3.3 Colour stability of tiger nut milk 51 4.2 Stabilisation of tiger nut milk 53 4.2.1 Effects of enrichments on the stability of tiger nut milk 53 4.2.2 Effects of pH and temperature on the stability of enriched TNM 56 4.2.3 Effects of enrichments on the rheology of tiger nut milk 58 4.3 Tiger nut protein extraction and characterisation 60 4.3.1 Protein extraction and fractionation 60 4.3.2 Molecular mass of tiger nut protein 62 4.3.3 Thermal denaturation of tiger nut protein 63 4.3.4 Isoelectric point of tiger nut proteins 66 4.4 Properties of fermented tiger nut milk enriched with proteins 67 4.4.1 Acidification and gel formation during fermentation 67 4.4.2 Microbiological properties of fermented enriched tiger nut milk 70 4.4.3 Physico-chemical properties of fermented enriched tiger nut milk 71 4.4.4 Sensory properties of fermented tiger nut milk products 76 4.5 Microbial transglutaminase and fermented tiger nut milk property 77 4.5.1 Effects on tiger nut milk fermentation 77 4.5.2 Microbiological properties during storage of fermented product 81 4.5.3 Physico-chemical properties during storage of fermented product 83 4.5.4 Effects on colour of fermented tiger nut product 86 5. Conclusions and outlook 88 Bibliography 90 List of figures 111 List of tables 115 List of Publications 116 Poster and presentations 116

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