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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.
821

Híbrido de sorgo para pastejo: manejo da cultura, crescimento no outono, aspectos do valor nutritivo e produção de leite

Simili, Flávia Fernanda [UNESP] 29 June 2007 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:33:33Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-06-29Bitstream added on 2014-06-13T20:05:35Z : No. of bitstreams: 1 simili_ff_dr_jabo.pdf: 417973 bytes, checksum: d0337e8233e7eba6a414318a41ab8024 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Quatro experimentos foram conduzidos na Agência Paulista de Tecnologia dos Agronegócios APTA – Ribeirão Preto, nos anos de 2004, 2005 e 2006, com os objetivos de determinar a melhor densidade de semeadura e espaçamento no plantio do híbrido de sorgo cv. 1P400; analisar o crescimento e a quantidade de ácido cianídrico nas folhas do híbrido de sorgo cv. 1P400 para determinar o melhor momento de entrada dos animais na pastagem; conhecer a qualidade das folhas e dos colmos do híbrido de sorgo cv. 1P400 e do capim-tanzânia através da degradabilidade in situ, proteína bruta e fibra em detergente neutro; avaliar a produção de leite do sistema de lotação rotacionada do híbrido de sorgo cv. 1P400 como alternativa de manejo alimentar no outono, sendo as vacas alimentadas com e sem uso de concentrado na dieta. Conforme os resultados experimentais, recomenda-se que o híbrido de sorgo cv. 1P400 seja semeado com 12 kg/ha, com 0,80 metros de espaçamento e que os animais iniciem o pastejo quando as plantas estiverem com altura entre 0,80 e 1,0 metro. Os colmos do híbrido de sorgo cv. 1P400 têm maior degradabilidade que os colmos do capim-tanzânia no outono, enquanto que as folhas das duas gramíneas apresentam degradabilidade semelhantes. A produção de leite de vacas mestiças em sistema de pastejo rotacionado no híbrido de sorgo 1P400 consumindo concentrado foi o melhor tratamento, sendo assim, uma alternativa de manejo alimentar no outono. / Four trials were conducted on the Agencia Paulista de Tecnologia dos Agronegócios APTA – Ribeirão Preto in 2004, 2005 and 2006 to establish the best plant density and row length on hybrid sorghum cv. 1P400; to study the plant growth and the cianidric acid levels on leaves on hybrid sorghum cv. 1P400; to study the leaf and stem quality of hybrid sorghum cv. 1P400 and Tanzania grass by the in situ degradability, crude protein and neutral detergent fiber analyses; to evaluate the milk production under rotational grazing system of hybrid sorghum cv. 1P400 as an alternative of foodhandling during autumn for cows with and without concentrate supplementation. Results showed that hybrid sorghum cv. 1P400 has to be cultivate using 12 kg/ha of seed and 0,80 meters of row distance and it has to be used for graze when the height of plants were between 0,80 and 1,00 meter. The hybrid sorghum cv. 1P400 stems have better degradability than Tanzania guinea grass stems on autumn while the leaves of both plants have similar degradability. The milk production of crossbred cows under rotational grazing system of hybrid sorghum cv. 1P400 with concentrate supplementation was the best treatment, consisting a viable alternative of food-handling during autumn.
822

Distribuição natural de espécies arbóreas em áreas com diferentes níveis de antropização visando integrar programa de conservação genética in situ

Calgaro, Hemerson Fernandes [UNESP] 23 February 2011 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:35:16Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-02-23Bitstream added on 2014-06-13T18:46:47Z : No. of bitstreams: 1 calgaro_hf_dr_ilha.pdf: 1024535 bytes, checksum: 534d1a478ba9f7e0da680f76b7d7f267 (MD5) / Universidade Estadual Paulista (UNESP) / Com o surgimento de áreas degradadas por ações antrópicas, os atributos físicos e químicos do solo e os caracteres silviculturais, passaram a ter importância quanto ao entendimento do processo sucessional das espécies arbóreas e no planejamento de recomposição da paisagem. Este trabalho teve como objetivo avaliar a distribuição de espécies arbóreas em áreas com diferentes níveis de perturbação antrópica, promover a compreensão da relação com os atributos químicos e físicos do solo; avaliar caráteres silviculturais e a relação como possível fator definidor do tipo vegetacional existente, para fins de integrar a programa de conservação genética in situ. O trabalho foi desenvolvido em área da Fazenda Experimental de Pesquisa e Extensão (FEPE) da UNESP de Ilha Solteira, no município de Selvíria - MS. Por meio de transecto foram demarcadas 64 parcelas equidistantes de 50 m com dimensões de 10x10 m. Sendo: 29 parcelas em área altamente antropizada (AAA); cinco em área medianamente antropizada (AMA); 15 em área pouco antropizada (APA); seis na mata ciliar do córrego da Véstia (Mata ciliar) e nove na Reserva legal. As amostras de solo foram coletadas em quatro profundidades (0,0 a 0,10 m; 0,10 a 0,20 m; 0,20 a 0,30 m e 0,30 a 0,40 m) para análise dos atributos físicos e duas profundidades (0,0 a 0,20 m e 0,20 a 0,40 m) para os atributos químicos além da avaliação dos caracteres silviculturais, como altura, diâmetro a altura do peito (DAP) e forma, e da autocorrelação espacial. Com base nos resultados conclui-se que: os atributos físicos e químicos do solo, associados ao nível de antropização e conservação das áreas, estão influenciando a ocorrência natural, diversidade de espécies e desenvolvimento dos indivíduos arbóreos; a altura, DAP e Forma, são bons indicadores para avaliar o crescimento das espécies arbóreas e relacioná-los aos... / With the emergence of areas degraded by human actions, the physical and chemical soil properties and forestry traits, have gained importance in understanding the process of succession of tree species and restoration of landscape. This study aimed to evaluate the distribution of tree species in areas with different levels of human disturbance, promote understanding of the relationship with the chemical and physical properties of soil; evaluate forestry charatcer relationship as possible and defining factor of the existing vegetation type, for to integrate the program of genetic conservation in situ. The work was developed at the Experimental Farm Research and Extension (FEPE) from UNESP of Ilha Solteira, Selvíria - MS. Through transect were marked 64 plots of 50 m equidistant with dimensions of 10x10 m. Where: 29 plots was located in area highly impacted (AAA), five in moderately disturbed area (AMA) in 15 in little disturbed area (APA); six in Riparian forest river of Véstia (Riparian Forest) and nine in the Legal Reserve. Soil samples were collected at two depths (0,0-0,20 m and 0,20-0,40 m) for the analysis of chemical and four depths (0,0-0,10 m, 0,10-0,20 m, 0,20-0,30 m and 0,30-0,40 m) for physical attributes; assessment of forestry traits such as height, diameter at breast height and shape, and spatial autocorrelation. Based on the results concluded that: the physical and chemical soil properties associated with the level of human disturbance and conservation areas, are influencing the natural occurrence, species diversity and development of the individual trees; the height, diameter at breast height and shape are good indicators to assess the growth of tree species and relate them to physical and chemical attributes of soil; the AAA, and the AMA to show similarity of soil physical properties; APA and Legal reserve have higher natural occurrence, number of individuals and number ... (Complete abstract click electronic access below)
823

Biorremediação de solos contaminados com hidrocarbonetos totais de petróleo - enfoque na aplicação do processo terraferm

Berger, Thomas Michael January 2005 (has links)
Bodenkontaminationen durch Mineralölkohlenwasserstoffe sind ein weltweites Umweltproblem. Die Kontaminatiosquellen stehen im Zusammenhang mit Förderung, Lagerung, Transport, Verteilung und Endlagerung von Erdöl und Erdölprodukten. Brasilien beginnt zurzeit einen Prozess der Altlastenerfassung und –erkundung und in Konsequenz dessen auch die Suche nach geeigneten Sanierungstechniken. Biologische Prozesse spielen eine immer stärkere Rolle insbesondere bei der Sanierung von Bodenkontaminationen mit organischen Substanzen. Diese Prozesse gelten als “ökologisch korrekter” und sind im Vergleich mit anderen Techniken mit geringeren Kosten und technischen Aufwand durchführbar. Ziel dieser Arbeit war es, die Anwendungsmöglichkeiten der biologischen Bodensanierung mittels des Terraferm® Verfahrens unter den Umweltbedingungen des Bundesstaates São Paulo, Brasilien zu überprüfen. Zu diesem Zweck wurde der Boden einer MKW-kontaminierte Fläche (Mina de Argila) in der Raffinerie REPLAN der PETROBRÁS S/A in Paulínia -SP ausgekoffert. Es wurden zehn Bodenproben in Bezug auf ihre physikalisch-chemischen Eigenschaften MKW, PAK, BTEX, Metalle (Cr, Zn, Pb, Ni, Cu, Cd, As, Hg, Fe, Ta), Wassergehalt, pH, Korngröße analysiert. Drei Proben mit durchschnittlichen MKW-gehalten wurden zur Überprüfung der biologischen Sanierbarkeit und der Bestimmung der Kontrollparameter für den später Sanierungsdurchführung Säulenversuchen unterzogen. Insgesamt wurden 72.384t kontaminierten Bodens ausgekoffert, wovon 21.050t der Abfallklasse II (nach NBR 10004) zugeordnet wurden und direkt auf eine Mülldeponie verbracht wurden. Es wurden 51.334t der Abfallklasse 1 in die Bodenreinigungsanlage der Firmen SAPOTEC/ESTRE in Paulínia - SP mittels des Terraferm® Verfahrens behandelt. Dieses Verfahren ist darauf ausgelegt, alle für den biologischen Abbau nötigen Prozessparameter im Optimum zu halten. Die Behandlung erfolgt in Hallen auf versiegeltem Untergrund und die dabei freigesetzten Schad- und Geruchsstoffe werden gefasst und einer Abluftreinigung zugeführt. Nach der Vorbehandlung (Aussortierung von Störstoffen, Zugabe von Strukturmaterial, Durchmischung) mittels speziellem Aufbereitungsaggregat wurden insgesamt elf Behandlungsmieten aufgesetzt. Der Sauerstoffgehalt, Bodenfeuchte und Nährstoffgehalte wurden im Optimalbereich gehalten. Die Analysen und die Säulenversuche bestätigten die biologische Sanierbarkeit des Bodens. Die Abbauraten in den Säulenversuchen lagenzwischen 70,2% und 88,6% in 14 Tagen. Diese hohen Abbauraten lassen sich durch die Zusammensetzung der MKW begründen, die sich hauptsächlich aus gut abbaubaren n-Alkanen und iso-Alkanen bestehen. Die durchschnittliche Abbaurate bei den elf Behandlungsmieten lag bei 80,88%, wobei die niedrigste bei 54,71% und die höchste Abbaurate bei 97,97% lagen. Die statistische Auswertung ergab, dass sich die Mittelwerte der MKW-gehalte während der Behandlung signifikant voneinander unterscheiden (<0,01). Die im Rahmen dieser Arbeit durchgeführten Versuche bestätigen den erfolgreichen Einsatz des Terraferm® Verfahrens unter Umweltbedingungen des Bundesstaates São Paulo, Brasilien. Die starke Variabilität der Abbauraten in den Behandlungsmieten deutet aber auf einen weiteren Forschungsbedarf, insbesondere hinsichtlich des Temperatur-einflusses, hin. / Contaminações de solos com hidrocarbonetos de petróleo são um problema ambiental com abrangência mundial devido à alta demanda de produtos refinados de petróleo. As fontes são múltiplas e estão relacionadas à exploração, produção, armazenamento, transporte, distribuição e à destinação final de petróleo e seus derivados. Hoje o Brasil está iniciando um processo de avaliação e cadastramento de suas áreas contaminadas e, conseqüentemente, está procurando alternativas para a remediação das mesmas. Processos biológicos estão ganhando cada vez mais importância no tratamento, especialmente de solos contaminados com compostos orgânicos. Estes métodos são favorecidos por serem mais limpos, com custos baixos e de mais fácil aplicação em escala industrial. Assim, com o objetivo de verificar a aplicabilidade da biorremediação através do processo Terraferm® às condições ambientais do Estado de São Paulo, Brasil, foi realizada a remediação ex situ de uma área contaminada com TPH, chamada Mina de Argila na Refinaria de Paulínia – REPLAN da PETROBRÁS S/A, em Paulínia - SP. Foram analisadas dez amostras de solo contaminado em relação aos parâmetros físico-químicos TPH, PAH, BTEX, metais (Cr, Zn, Pb, Ni, Cu, Cd, As, Hg, Fe, Ta), umidade, pH, oxigênio e granulometria. Três amostras com valores médios de TPH foram submetidas a ensaios de coluna para verificação da biotratabilidade do material e para definição de parâmetros de controle do processo em escala industrial. Foram removidos um total de 72.384t de material contaminado. Deste total, 21.050t foram classificadas como resíduo classe II segundo a NBR 10004 e encaminhadas para um aterro sanitário, e 51.334t foram classificadas como resíduo classe I, sendo destinadas à estação de biorremediação das empresas SAPOTEC/ESTRE, em Paulínia - SP. O solo contaminado foi tratado com o processo Terraferm®, que visa à otimização dos parâmetros que influenciam diretamente a atividade microbiana necessária para a biodegradação. O tratamento é feito em galpões com piso impermeabilizado e com um sistema de captação e tratamento das emissões geradas durante o processo de biodegradação. Após o pré-tratamento em máquina especial, que consiste na separação dos materiais não-tratáveis, na homogeneização e na adição de material estrutural, o solo contaminado foi colocado em onze pilhas de tratamento. Os fatores chave como o teor de oxigênio, a umidade e os nutrientes foram mantidos nas faixas consideradas ótimas. A caracterização química e o ensaio de coluna comprovaram a biotratabilidade do solo. Noensaio em coluna, obteve-se taxas de degradação entre 70,2% e 88,6% em 14 dias. Essas taxas altas são explicadas pela composição do TPH que consiste, neste caso, basicamente de n-alcanos e iso-alcanos considerados de fácil degradação biológica. A taxa média de degradação obtida no tratamento das onze pilhas foi de 80,88%, sendo a menor de 54,71% e a maior de 97,97%. Na análise estatística, verificou-se que as médias das concentrações de TPH durante cada período de tratamento diferem significativamente (<0,01). O trabalho conclui que o processo Terraferm® foi aplicado com sucesso nas condições ambientais do Estado de São Paulo, Brasil. Entretanto, os resultados do tratamento mostram uma alta variabilidade das taxas de degradação nas pilhas, que indica a necessidade de novas pesquisas, especialmente sobre a influência da temperatura no processo. / Soil contaminations with petroleum hydrocarbons are a worldwide environmental problem due to the high demand for refined petroleum products. Contamination sources are multiple and related to the exploration, production, storage, transportation, distribution, and final disposal of petroleum and its derivatives. Nowadays Brazil is starting to assess and record its contaminated areas and consequently search for alternatives for their remediation. Biological processes are gaining more and more importance, specially in the treatment of soils contaminated by organic compounds. These methods are favored for being cleaner, with lower costs, and more easily applicable to industrial scale. Therefore, with the objective of verifying the applicability of bioremediation to the environmental conditions of São Paulo State, Brazil, the ex situ remediation of a contaminated area by TPH was carried out by using the Terraferm® process. The area called Mina de Argila was located in the Paulínia Refinery – REPLAN, which belongs to PETROBRÁS S/A (the country's leader in the exploration, production, and distribution of petroleum products). Ten samples of contaminated soil were analyzed in relation to the physical-chemical parameters TPH, PAH, BTEX, metals (Cr, Zn, Pb, Ni, Cu, Cd, As, Hg, Fe, Ta), humidity, pH, oxygen and texture. Three samples with average values of TPH were submitted to column tests in order to assess the material biotreatability and define the control parameters of the process on industrial scale. A total of 72,384t of contaminated soil were removed. From this total, 21,050t were classified as class II waste according to NBR 10004 and sent to a landfill, and 51,334t were classified as class I waste and sent to the bioremediation plant of the companies SAPOTEC/ESTRE, in Paulínia – São Paulo State. The contaminated soil was treated with the Terraferm® process whose purpose is to optimize the parameters which directly influence the microbial activity necessary for biodegradation. The treatment was carried out in sheds with waterproof floor and a collection and treatment system for the emissions generated in the biodegradation process. After the treatment in a special machine, which consists in separating non-treatable materials, homogenizing, and adding structural material, the soil was placed into eleven treatment piles. The oxygen content, humidity, and nutrients were kept within a range considered optimum. The chemical characterization and the column test proved the soil biotreatability. In the column test, the degradation rates were between 70.2% and 88.6% in 14 days. These high rates are due to the TPHcomposition, which in this case basically consists in n-alkenes and iso-alkenes of easy biological degradation. The average degradation rate verified in the treatment of the eleven piles was of 80.88%, the lowest being 54.71% and the highest 97.97%. In the statistical analysis, it was verified that the average concentrations of TPH during each treatment period differ significantly (<0.01). The conclusion of this work is that the Terraferm® process was successfully applied to the environmental conditions of São Paulo State. However, the treatment results show a high variability in the degradation rates of the piles, which indicates the need for further research, specially on the influence of temperature on the process.
824

Modelando ocorrência e abundância de espécies arbóreas no entorno de uma usina hidroelétrica no sul do Brasil

Guarino, Ernestino de Souza Gomes January 2010 (has links)
Modelos de ocorrência e abundância de espécies são importantes ferramentas para a elaboração de estrategias para a conservação da biodiversidade. Nestes artigos aplicamos, pela primeira vez, modelos de distribuição e abundância no entorno de uma Usina Hidroelétrica no Sul do Brasil, com o objetivo de mostrar possíveis aplicações destas técnicas no planejamento de ações de coleta e conservação, in situ e ex situ, destas espécies. Nossos objetivos secundários foram (i) modelar a ocorrência e abundância de plantas em um trecho da bacia do rio Pelotas e (ii) verificar o efeito da detectabilidade em modelos de ocorrência. Para tanto dividimos a tese em dois capítulos e cinco questões. No primeiro capítulo procuramos responder as seguintes questões: (1) existe relação entre a probabilidade de ocorrência e a abundância observada? (2) Modelos baseados na abundância são melhores para predizer a ocorrência de espécies do que modelos baseados apenas na ocorrência das espécies? No segundo capítulo, tentamos responder se (3) amostragens exaustivas, com presenças e ausências bem descritas, produzem modelos de ocorrência mais precisos? (4) Se a relação entre a ocorrência da espécie e as variáveis ambientais que descrevem sua distribuição é alterada de acordo com a detectabilidade? (5) Qual o impacto de falsos zeros na área ocupada estimada para a espécie? O trabalho foi realizado no entorno da UHE Barra Grande, erguida no rio Pelotas, entre os Estados de Santa Catarina e Rio Grande do Sul. Localizada na bacia do rio Pelotas, seu reservatório ocupa uma área de aproximadamente 90 km2 e seu entorno perfaz uma área aproximada de 4.600 km2, onde amostramos 388 parcelas georreferenciadas (10 x 50 m) distribuídas aleatoriamente. Em cada parcela contamos o número de indivíduos de nove espécies arborescente com altura ≥ 1,5 m. No primeiro artigo, modelamos, utilizando modelos lineares generalizados (GLM), a distribuição e abundância das nove espécies estudadas em relação a 15 variáveis ambientais, e demonstramos que modelos de ocorrência são mais precisos do que modelos de abundância. Demonstramos também que a probabilidade de ocorrência é positivamente correlacionada com a abundância observada, o que abre a possibilidade de utilizarmos a probabilidade de ocorrência como um indicador da abundância das espécies. No segundo capítulo, verificamos o impacto de falhas de detecção em modelos de distribuição de espécies, utilizando como espécie modelo A. angustifolia. Simulamos o impacto de falsos zeros na precisão dos modelos, na seleção das variáveis resposta (variáveis ambientais) e nas estimativas de área ocupada pela espécie. A redução da detectabilidade ocasionou alterações tanto na precisão dos modelos quanto na área estimada de ocorrência e nas variáveis ambientais que explicam a ocorrência de A. angustifolia. A área ocupada não apresentou padrão bem definido, porém mostrou tendência de elevação de acordo com a diminuição da detectabilidade, elevando com isso o erro de comissão dos modelos. A precisão dos modelos (AUC e correlação entre probabilidade de ocorrência e abundância observada), apresentou queda em relação ao redução da detectabilidade, enquanto apenas uma variável ambiental foi incluída em todos os modelos (pH do solo). Existe um grande possibilidade de uso destas técnicas como informação básica para planos de conservação, monitoramento e manejo da biodiversidade no entorno de empreendimentos hidroelétricos, porém, para que possamos tirar inferências fortes sobre as espécies e ecossistemas em questão, devemos observar sempre a necessidade de levar em conta os impactos da detecção imperfeita das espécies. / Species occurrence and abundance models are important tools in the development of biodiversity conservation strategies. This study presents, for the first time, the application of distribution and abundance models in the environment surrounding a hydropower dam in southern Brazil. The aim is to demonstrate the possible application of these techniques in planning collection and conservation strategies of the species inhabiting the area, in situ and ex situ. We also aimed at (i) modeling the occurrence and abundance of plants in a section of the Pelotas River basin and (ii) verifying the effect of detectability in occurrence models. This thesis was therefore divided into two chapters and five questions. The first chapter is an attempt to answer the following questions: (1) Is there a relationship between occurrence probability and abundance? (2) Are models based on abundance better to predict the occurrence of species as compared to models that utilize only species occurrence? The second chapter addresses the questions: (3) Do exhaustive sampling procedures, with well-sampled presences and absences, lead to more accurate occurrence models? (4) Does detectability influence the relationship between species occurrence and environmental variables? (5) What is the impact of false zeros in the estimated area occupied by one given species? This study was conducted in the area surrounding the hydropower plant “Barra Grande”, in the Pelotas River, on the border of the Rio Grande do Sul and Santa Catarina states. Located in the Pelotas River basin, the dam occupies an area of approximately 90 km². The surrounding area accounts for 4,600 km², where 388 plots with 10 x 50 m were randomly distributed and georeferenced. In each plot, individuals of nine selected tree species taller than 1.5 m were surveyed. In the first paper, we modeled the distribution and abundance of the species studied using generalized linear models (GLMs), utilizing 15 environmental variables. Occurrence models were proved to be more accurate than abundance models. The positive correlation between occurrence probability and observed abundance was also demonstrated, which opens the possibility to utilize occurrence probability as an indicator of species abundance. The second chapter reports the impact of failures in detection in species distribution models, using A. angustifolia as model species. We simulated the impact of false zeros in model accuracy, in the selection of response variables (environmental variables) and in estimates of the area occupied by A. angustifolia. The decrease in detectability caused changes in both model accuracy and in the environmental variables that explain the occurrence of A. angustifolia. The area occupied did not have a well-defined pattern, though it showed a trend towards elevation, in accordance with the decrease in detectability, thus raising the commission error in the model. The accuracy of models (AUC and correlation between occurrence probability and observed abundance) decreased with the decrease in detectability, while only one environmental variable was included in all models (soil pH). These techniques offer great potential in the collection of essential information in biodiversity conservation, monitoring and managements strategies in hydropower projects. However, robust inferences about species and ecosystems in question can only be drawn considering the need to evaluate the impact caused by defective species detection.
825

Integration of in situ stress measurements in a non-elastic rock mass / L’intégration des mesures de contraintes in situ dans un massif rocheux non élastique

Gomes De Figueiredo, Bruno 10 September 2013 (has links)
Considérons un cas d’étude dans lequel les données produites par différentes techniques ont été obtenues en divers points d’une masse rocheuse où les effets topographiques sont très probablement significatifs. Les mesures ont été effectuées pour la conception du réseau hydroélectrique. Le réseau comprend une conduite hydraulique ainsi qu’une nouvelle centrale souterraine placée à mi-parcours de la conduite et sera principalement creusé dans le granite. Les diverses données ont été intégrées à un modèle continu équivalent afin d’évaluer le champ de contrainte régional et ainsi d’extrapoler les résultats des divers tests au volume de masse rocheuse concerné par le plan hydroélectrique. L'intégration des essais in situ et du modèle permet de déterminer les variations spatiales du champ de contrainte. Il est ainsi possible d’identifier le mécanisme de chargement à l’origine du champ de contrainte mesuré ainsi que le comportement rhéologique à long terme du géomatériel équivalent considéré. / A case study is considered in which data produced by different techniques have been gathered in various locations within a rock mass in which topography effects are most likely significant. Measurements were performed for the design of a re-powering scheme that includes a new hydraulic conduit and an underground cavern that will primarily be excavated in granite. An integrated approach for extrapolating the results from the various in situ tests to the rock mass volume of interest for the hydroelectric power scheme is presented. This approach includes the development of an equivalent continuum mechanics model. The integration of in situ tests and numerical modelling enables to determine the stress spatial variation which helps ascertain the loading mechanism at the origin of the measured stress field as well as the long-term rheological behavior of the equivalent geomaterial under consideration.
826

Dor no pós-operatório da ceratectomia fotorrefrativa (PRK) com fosfato de codeína 30 mg/ paracetamol 500 mg: ensaio clínico aleatório / Codeine plus acetaminophen for pain afier photorefractive keratectomy: a randomized, double-blind, placebo-controlled add-on trial

Vinícius Borges Porfírio Pereira 02 March 2018 (has links)
Introdução: A ceratectornia fotorrefrativa (PRK) é uma das técnicas de cirurgia refrativa mais empregadas no mundo. A despeito de sua efetividade e segurança no tratamento de miopia, hipermetropia e astigmatismo, a dor permanece ainda como um dos grandes desafios no período pós-operatório da PRK. Embora a associação dos fármacos codeína (opióide oral) e paracetamol (analgésico) seja amplamente empregada no período pós-cirúrgico de várias especialidades médicas. a eficácia e segurança dessa associação não foi avaliada no manejo da dor no pós-PRK. Objetivo: O objetivo da presente tese foi testar a combinação codeína + paracetamol no manejo da dor pós-PRK. Métodos: Trata-se de um ensaio clínico controlado por placebo, randomizado, paralelo e duplo-cego. O subdelineamento é do tipo \"add-on \", isto é. o grupo da intervenção recebeu a terapia padrão + a intervenção. enquanto o grupo controle recebeu a terapia padrão + placebo. A amostra foi composta por 41 participantes (82 olhos) - por meio do delineamento \"olhos pareados\" (paired-eye design), ou seja, o olho foi a unidade de análise. As cirurgias foram realizadas com duas semanas de intervalo. Um olho recebeu codeína (30 mg) + paracetamol (500 mg) 4x1dia por quatro dias (período A), enquanto o outro olho recebeu placebo 4x/dia por quatro dias (período B). Tanto a alocação (intervenção ou placebo) quanto a ordem (A-B ou B-A) foram aleatorizadas. A dor foi avaliada por meio de três escalas: questionário de dor McGill (MPQ). Inventário Resumido da Dor (I3PI) e escala visual análoga (EVA) nos períodos I, 24, 48 e 72 horas após a cirurgia. O período de seguimento total foi de quatro meses. Resultados: A idade média dos pacientes foi de 30 anos (rnin-máx: 22-52), dos quais 67% foram mulheres. Dos 82 olhos inicialmente arrolados no estudo, 80 completaram os quatro meses de seguimento (40 na intervenção e 40 no placebo). Os escores medianos de dor mensurados pela EVA foram significativamente mais baixos no grupo da intervenção comparado com o grupo placebo - durante todo o período do pós- cirúrgico imediato (1-48 horas). Os eventos adversos foram brandos e de fácil manejo clínico; os mais comuns foram sonolência, náusea e constipação. Após um seguimento de quatro meses, não foi observado nenhum retardo na resposta de cicatrização da córnea ou haze. Conclusões: A combinação de codeína (30mg) e paracetamol (500mg) via oral (4x/dia) é segura e significativamente superior ao placebo para o controle da dor após a PRK / Introduction: Photorefractive keratectomy (PRK) is one of most widely performed types of refractive surgery in the world. In spite of its effectiveness and safety for the treatment of myopia, hypermetropia and astigmatism, pain remains one of the biggest clinical challenges during the early postoperative period after PRK. Although the combination of codeine (an oral opioid) plus acetaminophcn (an analgesic) has been widely used during the postoperative period in many medical specialties, both its efficacy and safety have not been formally investigated for pain control after PRK. Objective: To carry out a randomized, controlled c1inical trial, specifically dcsigned to test whether the combination of codeine + acetaminophen is efficacious and safe for pain control after PRK. Methods: Double-blind (patients and outcome assessors), randomized, parallel, placebo-controlled trial. An add-on design was adopted. tl.at is, the intervention group received the standard of care therapy + codeine/acetaminophen, whereas the control group received the standard o[ care therapy + placebo. The sample encompassed 41 participants (82 eyes) through the \"paired-eye design\". In other words, the eye was the unity of analysis. Surgeries were performed two weeks ap311. One eye received codeine (30mg) + acetaminophen (500mg) 4x/day for four days (period A), whereas the fellow (control) eye received placebo 4x/day for four days (period B). Both treatrnents (intervention or placebo) and treatment order (A-B or B-A) were randomly chosen. Pain was asscsscd at 1, 24, 48 and 72h postopcrativcly by three scales: visual analogue scale (VAS), McGill Pain Questionnaire (MQP) and Brief Pain Inventory (BPI). The total follow-up period was 4 months. Results: The mean age of patients was 30 years (rnin-max: 22-52) and 67% (27/40) were female. Ofthe initial 82 eyes, 80 completed the trial (40 in the intervention 31m, 40 in the placebo arm). Median pain scores as measured by the VAS were significantly lower during treatment with codeine/acetaminophen compared to the placebo throughout the early postoperative period (1-48h). Virtually identical results were obtained by the MQP and BPI scales, suggesting that the intervention can have a positive impact not only on the pain intensity, but also on the multidimensional aspects of pain, such as interference on activities of daily living as well as emotional status. Adverse events (AEs) were usually mild and easily managed. The most common AEs were drowsiness, nausea and constipation. After a follow- up period of four months, no case of delayed epithelial healing or haze was observed in both treatment arms. Conclusions: When added to the standard of care therapy, the oral combination of codeine (30mg) and acetaminophen (500mg) given 4x/day was safe and significantly superior to placebo for pain control after PRK
827

Développement de nanocomposites à propriétés piézoélectriques et optiques non-linéaires / Development of piezoelectric and nonlinear optical nanocomposite materials

Houf, Latifa 28 October 2011 (has links)
Le développement de nouveaux capteurs, transducteurs et de dispositifs intégrés optoélectroniques et piézo-électriques nécessite l'élaboration de nouveaux matériaux avec des propriétés mécaniques, optiques et électriques couplées. Dans cette perspective, les nanocomposites à base de nanocristaux inorganiques non centrosymétriques dispersés dans une matrice polymère peuvent donner à la fois des propriétés piézoélectriques et optiques non-linéaires. Cependant, la dispersion et l’orientation des nanocristaux dans la matrice sont primordiales si on souhaite un comportement collectif des nanocristaux individuels et des propriétés résultantes significatives. Dans ce travail, nous avons utilisé des cristaux d’iodate de fer (Fe(IO3)3) comme nano-charges inorganiques et le PMMA/ PTMPTA comme matrice polymère. La réponse optique non-linéaire du Fe(IO3)3 est comparable à celle des cristaux les plus efficaces tels que BaB2O4 et LiNbO3. Le comportement piézoélectrique du matériau massif n’étant pas référencé, sa structure cristalline laisse toutefois envisager des propriétés piézoélectriques intéressantes. Par ailleurs, la matrice polymère a été choisie pour sa simplicité d'utilisation et de production, son coût relativement faible, sa versatilité et sa facilité de mise en forme. Les nanocomposites peuvent être élaborés par deux voix différentes : la première consiste à disperser mécaniquement des nanocristaux fonctionnalisés dans un polymère ou dans un solvant de polymère approprié et la deuxième concerne la polymérisation in-situ de microémulsions composées du monomère liquide. Les synthèses en microémulsions inverses ont été privilégiées pour d’une part élaborer des nanocristaux d’iodate de fer de taille et de forme contrôlées puis, d’autre part, photo-polymériser des couches minces déposées à la tournette. Un aspect très original de ce travail consiste en l’utilisation de la Diffusion Hyper-Rayleigh pour étudier in-situ les cinétiques de cristallisation des particules d’iodate de fer en fonction des conditions expérimentales de synthèse à savoir, la température et la composition des microémulsions. Cette technique qui consiste à détecter les réponses optiques non-linéaires des suspensions de nanoparticules en microémulsions a été combinée avec d’autres méthodes expérimentales plus classiques comme la diffraction des rayons X, la diffusion dynamique de la lumière et la microscopie électronique en transmission. Cela a permis d’élucider les mécanismes de croissance des nanocristaux d’iodate de fer en microémulsions inverses. Par la suite, des couches minces nanocomposites ont été préparées après orientation sous champs électriques des nanocristaux polaires dispersés dans le MMA. Les caractérisations mécaniques, optiques non linaires et piézoélectriques de ces couches sont encourageantes. / The development of new sensors, transducers and integrated optoelectronic and piezoelectric devices requires the preparation of new materials that link mechanical, optical and electrical properties. In this perspective, it is expected that nanocomposite materials with inclusions of acentric inorganic nanocrystals in a polymer matrix will give rise to both piezoelectric and nonlinear optical (NLO) properties. Dispersion and orientation of nanocrystals in the polymer matrix are however crucial to obtain a collective response of individual nanocrystals and significant resultant properties. In this work, iron iodate (Fe(IO3)3) nanocrystals were used as nanofillers of a PMMA / PTMPTA polymer matrix. The nonlinear optical response of Fe(IO3)3 is comparable to the most effective NLO crystals such as LiNbO3 and BaB2O4. Good piezoelectric properties are also expected due to the material crystalline structure. Moreover, the polymer matrix was chosen for its ease of use and production, its relatively low cost, versatility and ease in shaping. Elaboration of nanocomposites is usually based on two different experimental procedures: mechanical dispersion of functionalized nanocrystals in a suitable polymer or polymer solvent is a first route whereas in-situ polymerization of reverse microemulsions for which a liquid monomer is the oil phase is the second one. Water-in-Oil (W/O) microemulsions were preferred in order to control the size and shape of as-obtained iron iodate nanocrystals and then to polymerize spin-coated thin films. A very original aspect of this work is the implementation of the Hyper-Rayleigh Scattering technique to probe in-situ the crystallization kinetics of iron iodate nanoparticles according to the experimental conditions (synthesis temperature and microemulsions composition). Detection of the second-harmonic scattered light combined with more conventional experimental techniques such as X-ray diffraction, dynamic light scattering and Transmission Electron Microscopy allowed us to understand the growth mechanisms of iron iodate naocrystals in W/O microemulsions. Nanocomposite thin films were then spin-coated after electric fields orientation of dispersed polar nanocrystals in MMA.
828

Electrodéposition et la caractérisation de nanofilms palladium sur Au (111) pour le stockage d'hydrogène Electro-deposition and characterization of palladium nanofilms on Au (111) for hydrogen storage / Electro-deposition and characterization of palladium nanofilms on Au(111) for hydrogen storage

Wang, Liang 21 December 2012 (has links)
Ce travail de thèse s’est intéressé au dépôt électrochimique de filmsde palladium ultra-minces sur Au(111), à leur caractérisation et àl’insertion d'hydrogène dans ceux-ci. La caractérisation des nanofilmsen milieu sulfurique montre des signatures bien définies, qui évoluentavec l’épaisseur des dépôts. Nous avons pu attribuer à chaque pic uneréaction spécifique, en accord avec les mécanismes de croissancerévélés par les mesures SXRD in situ. La croissance pseudomorphede la 1ère couche se fait avec une première étape d'adsorption, suiviepar un mécanisme de nucléation et croissance. La croissance 3D de latroisième couche démarre avant la fin de la deuxième couchepseudomorphe.L'absorption d'hydrogène dans les nanofilms a été étudiée en milieusulfurique. L’isotherme d’insertion présente un élargissement dudomaine de la solution solide, un plateau avec une pente dans ledomaine bi-phasique et une diminution du taux maximal d'insertion del’hydrogène par rapport au Pd massif. Ce taux diminue avecl’épaisseur mai approche celui de Pd massif au déla delà de 15 MC.Deux éléments ont été considérés pour expliquer le comportement desisothermes: les deux premières couches pseudomorphes sontcontraintes par le support et des « tours » tridimensionnelles relaxéesse forment au delà de la 2ème couche. / This thesis focused on electro-deposition, characterization andhydrogen strorage of ultrathin palladium film over Au(111). Theelectrochemical characterization of the nanofilms in sulphuric mediumshows well-defined features evolving with the deposit thickness. Wecould assign each peak to a specific reaction, in agreement with thegrowth mechanisms revealed by in situ SXRD measurements. Thepseudomorphic growth of the 1st layer firstly undergoes an adsorptionstep, followed by nucleation and growth mechanism, as shown bycurrent transient measurements. 3D growth of the 3rd layer beginsbefore the completion of the second pseudomorphic one.Hydrogen absorption in the nanofilms was studied in sulphuric mediumas well. Isotherms show an enlargement of the solid solution domain, asloppy plateau in the two-phase region, a decrease of maximuminsertion ratio (H/Pd)max compared to bulk Pd. This last valuedecreases with film thickness, approaching bulk Pd beyond about15 ML. Two contributions were considered to explain the isothermbehaviour: the two first Pd layers heavily constraint by the substrateand the 3D “towers like” relaxed structures growing on the secondpseudomorphic Pd layer.
829

Experimental investigation of microstructural changes in deforming granular media using x-ray tomography / Étude expérimentale de l'évolution de la microstructure d'un milieu granulaire sous chargement mécanique à l'aide de la tomographie RX

Ando, Edward 05 February 2013 (has links)
Cette thèse présente un travail expérimental dans le domaine de la mécanique des milieux granulaires.Ce travail introduit une nouveauté fondamentale: durant la déformation d’échantillonsde sable en compression triaxiale classique, leur micro-structure est enregistrée par tomographieà rayons-x en environ 15 étapes de déformation différentes.Afin que tous les grains d’un échantillon soient individuellement visibles dans les imagesde tomographie, les échantillons sont considérablement réduits pour qu’ils mesurent 11 mm endiamètre et 22 mm en hauteur. Cela permet d’identifier et d’individualiser tous les plus decinquante mille grains d’un échantillon.Dans ce travail expérimental, une série d’essais triaxiaux a été réalisée sur trois sables naturels(le sable d’Hostun, le sable d’Ottawa et des Caicos ooids, tous à partir des états initiauxrelativement denses), à deux valeurs de pression de confinement différents (100 et 300 kPa).Dans les images 3D résultantes de la reconstruction des acquisitions tomographiques réaliséesau cours de chaque essai, les grains sont identifiés dans chaque état en utilisant un algorithmede type watershed (ligne de partage des eaux) classique. À partir de ces données discrétisées,des techniques ont été mises au point pour caractériser les contacts grain-à-grain mais aussipour mesurer la cinématique de tous les grains identifiés entre les états pour lesquels des imagestridimensionnelles existent. La cinématique des grains est mesurée avec deux outils spécialementdéveloppés: “ID-Track” suit les grains et donne leurs déplacements; cette information est ensuitenécessaire pour une technique hybride de corrélation d’images discrète pour mesurer la rotationde chaque grain.Des mesures à l’échelle du grain sont présentées en détail pour un essai, et sont ensuitecomparées à des essais dans des conditions différentes. L’objectif est de mettre en évidence lesmicro-mécanismes responsables des différents comportements macroscopiques observés pour cesmatériaux. Cette comparaison met en évidence certains micro-mécanismes importants tels que,par exemple, la déformation d’un échantillon. Celle-ci est concentrée dans une bande de cisaillementbien développée qui correspond à une bande de grains avec des rotations intenses. Dans unéchantillon de grains arrondis, cette bande – définie par des grains – est très nette. Par contre,avec des grains anguleux, les rotations des grains dans la bande “polluent” les grains voisins;leur forme facilite l’engrenage entre grains, qui limite aussi les grosses rotations individuelles desgrains. Cette différence de mécanisme de déformation est utilisée pour expliquer la différencedans la contrainte résiduelle observée à macro-échelle. Des signes de déformation localisée sontsystématiquement observés en train de se produire avant le pic de déformation des échantillons etdes systèmes complexes de chaînes de rotations de grains (qui correspondent aussi à une mesurelocale de déformation calculée avec les déplacements des grains) sont remarquées autour du picde la réponse macroscopique de chaque échantillon. / This doctoral thesis presents an experimental investigation into the mechanics of granular media.The novelty that this work brings is that the specimens of sand tested in this work are systematicallyand non-destructively imaged using x-ray tomography. Sample size is considerably reducedfrom standard (specimens measure approximately 22 mm height by 11 mm diameter), allowingentire specimens to be scanned at a sufficiently high resolution to identify all the grains (morethan fifty thousand) in each specimen.A campaign of triaxial compression tests has been run on a series of three different naturalsands with different grain shapes (Hostun sand, Ottawa sand and Caicos ooids – all prepared atrelatively dense initial states), and tested at 100 or 300 kPa cell pressure. In each test around 15x-ray scans are performed. In the 3D images resulting from the reconstruction of the x-ray scansperformed, grains are identified each state using a standard watershed algorithm. Starting fromthese discretised data, techniques are developed in order characterise grain-to-grain contacts,as well as to measure the kinematics of all the identified grains between imaged states. Grainkinematics are measured with two specifically-developed tools: “ID-Track” to track grains yieldingtheir displacements, and a discrete image correlation technique to measure grain rotations.Grain-scale measurements are reported in detail for one test, and are then compared to testsin different conditions, in order to highlight the micro-mechanisms responsible for the observedmacroscopic behaviour. This comparison highlights some important micro-scale mechanisms suchas the increasing rotational frustration of more angular grains when the sample’s deformation isconcentrated in a fully developed shear band; this is used to explain to some extent the highervalue of their residual stress for these materials. Signs of localised deformation are seen to occurwell before the peak in many samples, and complex patterns of rotating grains (which match alocal, grain-based measurement of strain) are noticed around the peak of each sample’s response.
830

Analyses expérimentales de la réponse sismique non-linéaire du système sol-structure / Nonlinear seismic response of the soil-structure system : experimental analyses

Chandra, Johanes 28 October 2014 (has links)
La concentration de plus en plus importante de la population dans les milieux urbains exposés à une forte sismicité peut générer de plus en plus de dommages et de pertes. La réponse sismique en milieu urbain dépend des effets du site (direct amplification et non-linéarité du sol) et du couplage entre le sol et les structures (interaction sol-structure et site-ville). Par conséquent, la compréhension de la sismologie urbaine, c'est-à-dire le mouvement du sol intégrant l'environnement urbain, est critique pour réduire les dommages. Cela passe par la prédiction du mouvement du sol dans le milieu urbain, ingrédient fondamental à l'évaluation de l'aléa sismique. La prise en compte de l'amplification provoquée par la présence de sédiments est largement étudiée. Au contraire, la réponse non-linéarité du sol et du couplage entre le sol et la structure est rarement intégrée à la prédiction du mouvement du sol. A cause de leur complexité, ces problèmes ont toujours été abordés séparément. Dans ce contexte, cette thèse analyse la réponse non-linéaire du système sol-structure en intégrant la non-linéarité du sol et de l'interaction sol-structure. Deux travaux expérimentaux ont été conduits, avec comme but de proposer un proxy, rendant compte de la non-linéarité du sol. Le premier est l'essai en centrifugeuse qui reproduit à échelle réduite la réponse du sol et des structures. L'état de contrainte et de déformation est conservé en appliquant une accélération artificielle au modèle. Cet essai a été effectué à IFSTTAR Nantes dans le cadre de l'ANR ARVISE. Différentes configurations ont été testées, avec et sans bâtiments, sous différents niveaux de sollicitation, pour analyser la réponse du sol et des structures. Le deuxième utilise les enregistrements des réseaux accélérométriques verticaux de deux sites tests californiens : Garner Valley Downhole Arrat (GVDA) et Wildlife Liquefaction Array (WLA), gérés tout deux par l'Université de Californie, Santa Barbara (UCSB), Etats-Unis. La réponse in-situ est importante car elle décrit le comportement réel du site. Plusieurs informations décrivant les conditions de sites sont disponibles et les séismes enregistrés ont permis de tester plusieurs niveaux de déformations pour reconstruire la réponse globale de chaque site. De plus, le site GVDA est équipé d'une structure Soil-Foundation-Structure-Interaction (SFSI) qui a comme objectif d'étudier les problèmes d'interaction sol-structure. Dans les deux expériences, grace au réseau accélérométrique vertical dans le sol et la structure, on peut appliquer la méthode de propagation d'ondes 1D pour extraire la réponse de ces systèmes. Les ondes sont considérées comme des ondes SH qui se propage horizontalement dans une couche 1D. La méthode interférométrie sismique par déconvolution est appliquée pour extraire l'Impulse Response Function (IRF) du système 1D. On analyse ainsi la variation de Vs en fonction de la solliictation et à différente position dans le sol ainsi que la variation des éléments expliquant la réponse dynamique du système sol-structure. On propose au final un proxy de déformation permettant de rendre compte mais aussi de prédire la nonlinéarité des sols en fonction des niveaux sismiques subits. / The concentration of population in urban areas in seismic-prone regions can generate more and more damages and losses. Seismic response in urban areas depends on site effects (direct amplification and nonlinearity of the soil) and the coupling between the soil and structures (soil-structure and site-city interaction). Therefore, the understanding of urban seismology, that is the ground motion incorporating the urban environment, is critical to reduce the damage. This requires the prediction of ground motion in urban areas, a fundamental element in the evaluation of the seismic hazard. Taking into account the amplification caused by the presence of sediment has been widely studied. However, the non-linearity of the soil and the coupling between the ground and the structure is seldom integrated to the prediction of the ground motion. Because of their complexity, these problems have been addressed separately. In this context, this dissertation analyzes the non-linear response of the soil-structure by integrating the non-linearity of the soil and the soil-structure interaction. Two experimental studies were performed, with the aim of providing a proxy that reflects the non-linearity of the soil. The first is the centrifuge test that reproduces the response of soil and structures at reduced scale. The state of stress and strain is conserved by applying an artificial acceleration model. This test was performed at IFSTTAR Nantes in the framework of the ANR ARVISE. Different configurations were tested with and without buildings, under different stress levels, to analyze the response of the soil and structures. The second uses the vertical accelerometric networks of two sites in California: Garner Valley Downhole (GVDA) and the Wildlife Liquefaction Array (WLA), both managed by the University of California, Santa Barbara (UCSB), USA. In-situ response is important since it describes the actual behavior of the site. Information describing the conditions of sites is widely available and the earthquakes recorded were used to test several levels of shaking to reconstruct the overall response of each site. In addition, the GVDA site is equipped with a Soil-Foundation-Structure-Interaction structure (SFSI) which aims to study the problems of soil-structure interaction. In both experiments, thanks to the vertical accelerometer network in the ground and the structure we are able to apply the 1D wave propagation method to extract the response of these systems. The waves are considered as an SH wave which propagates in a 1D horizontal layer. Seismic interferometry by deconvolution method is applied to extract the Impulse Response Function (IRF) of the 1D system. Thus the analysis of the variation in function of elastic properties of the soil and the structure is done under several magnitude of shaking, including variation in depth and the elements of the total response of the structure including the soil-structure interaction. At the end, a deformation proxy to evaluate and also to predict the nonlinear response of the soil, the structure and the soil-structure interaction is proposed.

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