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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Anwendung und Entwicklung von mikrowelleninduzierten Plasmen für die analytische Atomspektrometrie

Engel, Ulrich. Unknown Date (has links)
Universiẗat, Diss., 2000--Dortmund. / Dateiformat: PDF.
2

Estudo biológico e comportamental de lagartas de Spodoptera frugiperda visando à produção de Baculovírus spodoptera

STINGUEL, P. 16 February 2016 (has links)
Made available in DSpace on 2016-08-29T15:36:27Z (GMT). No. of bitstreams: 1 tese_8392_Priscila Stinguel.pdf: 877170 bytes, checksum: 071244c6e1e6c327c4142c0a6d6a103b (MD5) Previous issue date: 2016-02-16 / A utilização de bioinseticida a base de Spodoptera frugiperda multiple nucleopolyhedrovirus (SfMNPV) possui potencial para o controle de Spodoptera frugiperda (Lepidoptera: Noctuidae), porém sua obtenção em larga escala depende da maximização da produção in vivo. Assim, alguns fatores biológicos e comportamentais devem ser estudados para aperfeiçoar a produção de SfMNPV com intuito de disponibilizar um bioinseticida eficiente, economicamente viável e que possa ser usado no manejo de S. frugiperda nos mais diversos sistemas agrícolas. Entre os fatores relacionados ao hospedeiro, a temperatura e a idade para inoculação do vírus são de extrema importância, pois interferem diretamente no ciclo de vida e na replicação viral. O comportamento também deve ser avaliado, para evitar condições de criação do hospedeiro que favoreçam o canibalismo e causa prejuízo na multiplicação in vivo do SfMNPV. Assim, objetivou-se determinar a melhor condição térmica para criar as lagartas e a idade ideal, para inocular e multiplicar o vírus no hospedeiro, bem como, verificar a ocorrência do comportamento canibal em lagartas de S. frugiperda. Os experimentos foram conduzidos no Laboratório de Controle Microbiano de Insetos do Núcleo de Desenvolvimento Científico e Tecnológico em Manejo Fitossanitário de Pragas e Doenças (NUDEMAFI), localizado no Centro de Ciências Agrárias da UFES, em Alegre, Espírito Santo, Brasil. A pesquisa foi desenvolvida em duas etapas, a primeira para determinar a condição térmica e a idade ideais para criar e inocular, respectivamente, o hospedeiro com o vírus, para multiplicação in vivo de SfMNPV. A segunda etapa foi para avaliar o comportamento canibal de lagartas da espécie S. frugiperda criadas a 22, 25 e 31°C, inoculadas com SfMNPV quando com idades de 10, 8 e 4 dias, respectivamente, e mantidas em diferentes densidades populacionais (5, 10, 25 e 50 lagartas por recipiente). A mortalidade diminuiu com o aumento da temperatura e da idade do hospedeiro nas temperaturas de 25, 28 e 31 °C. O aumento na taxa de canibalismo foi 12 diretamente proporcional à densidade populacional quando as lagartas foram criadas a 22 °C, inoculadas aos 10 dias de idade e 25 ºC, inoculadas aos 8 dias e atingiram 63,5 e 62,5%, respectivamente na densidade populacional de 50 lagartas. Mas, quando as lagartas foram criadas a 31ºC e inoculadas com idade de 4 dias, a densidade populacional não afetou o comportamento canibal, taxa média de 24%, inferior aos outros tratamentos com 50 lagartas por recipiente. Demonstrando que é viável para a multiplicação viral, criar lagartas a 31 °C e aos 4 dias de idade inocular o vírus, podendo a partir de então colocar até 50 lagartas por recipiente, o que reduz a mão-de-obra necessária para individualizar as lagartas e otimiza o espaço físico em uma biofábrica. Portanto, se para otimizar o processo produção viral e o serviço em uma biofábrica, é preciso maximizar a produção viral, reduzir o tempo de multiplicação do vírus e o canibalismo entre as lagartas, com ausência de contaminação da criação, a temperatura e idade ideais para criação massal de S. frugiperda e inoculação do vírus nas lagartas, respectivamente, visando produção de baculovírus em larga escala são de 31 ºC e 4 dias.
3

Rauschanalysen am induktiven, kapazitiven und mikrowelleninduzierten Plasma in Kombination mit unterschiedlichen pneumatischen Zerstäubern bei emissionsspektrometrischen Bestimmungen in wässrigen und organischen Medien

Nehm, Rainer. January 1999 (has links)
Dortmund, Univ., Diss., 1999. / Computerdatei im Fernzugriff.
4

Rauschanalysen am induktiven, kapazitiven und mikrowelleninduzierten Plasma in Kombination mit unterschiedlichen pneumatischen Zerstäubern bei emissionsspektrometrischen Bestimmungen in wässrigen und organischen Medien

Nehm, Rainer. January 1999 (has links)
Dortmund, Univ., Diss., 1999. / Computerdatei im Fernzugriff.
5

Multivariate analysis applied to the characterization of spent nuclear fuel

Dayman, Kenneth Joseph 05 November 2012 (has links)
The Multi-Isotope Process Monitor is being developed at Pacific Northwest National Laboratory as a method to verify the process conditions within a nuclear fuel reprocessing facility using the gamma spectra of various process streams. The technique uses multivariate analysis techniques such as principal component analysis and partial least squares regression applied to gamma spectra collected of a process stream in order to classify the contents as belonging to a normal versus off-normal chemistry process. This approach to process monitoring is designed to function automatically, nondestructively, and in near real-time. To extend the Multi-Isotope Process Monitor, an analysis method to char- acterize spent nuclear fuel based on the reactor of origin, either pressurized or boiling water reactor, and burnup of the fuel using nuclide concentrations as input data has been developed. While the Multi-Isotope Process Monitor uses gamma spectra as input data, nuclide activities were used in this work as an initial step before Nuclide composition information was generated using ORIGEN-ARP for different fuel assembly types, initial 235U enrichments, burnup values, and cooling times. This data was used to train, tune, and test several multivariate analysis algorithms in order to compare their performance and identify the technique most suited for the analysis. To perform the classification based on reactor type, four methods were considered: k-nearest neighbors, linear and quadratic discriminant analysis, and support vector machines. Each method was optimized, and its performance on a validation set was used to determine the best method for classifying the fuel reactor class. Partial least squares was used to make burnup predictions. Three models were generated and tested: one trained on all the data, one trained for just pressurized water reactors, and one trained for boiling water reactors. Quadratic discriminant analysis was chosen as the best classifier of reactor class because of its simplicity and its potential to be extended to classify spent nuclear fuel’s fuel assembly type, i.e, more specific classes, using nuclide concentrations as input data. In the case of predicting the burnup of spent fuel using partial least squares, it was determined that making reactor-specific partial least squares models, one trained for pressurized water reactors and one trained for boiling water reactors, performed better than a single, general model that was trained for all light water reactors. Thus, the the classifier, regression algorithm, and all the necessary intermediate data processing steps were combined into a single analysis method and implemented as a Matlab function called “burnup.” This function was used to test the analysis routine on an additional set of data generated in ORIGEN-ARP. This dataset included samples with parameters that were not represented in the development data in order to ascertain the analysis method’s ability to analyze data for which it has not been explicitly trained. The algorithm was able to achieve perfect binary classification of the reactor as being a pressurized or boiling water reactor on the dataset and made burnup predictions with an average error of 0.0297%. / text
6

Polymères à empreintes moléculaires : nouveaux outils prometteurs pour la synthèse organique / Molecularly imprinted polymers : new promising tools for organic sysnthesis

Le Foll, Alexandra 19 March 2010 (has links)
Le projet présenté dans ce manuscrit consiste à utiliser la technologie des polymères à empreintes moléculaires (MIPs) pour concevoir de nouveaux outils pour la synthèse organique. Dans un premier temps, nous nous sommes intéressés à l'étude du potentiel des MIPs en organocatalyse, par l'intermédiaire d'une activation entropique dans les empreintes. Pour cela, plusieurs organocatalyseurs de type quinine thiourée ont été synthétisés afin d'être intégrés dans les cavités du polymère. Malgré l'efficacité de l'impression montrée en HPLC, aucun effet bénéfique sur la vitesse ou l'énantiosélectivité de la réaction n'a pu être mis en évidence par l'utilisation des différents MIPs synthétisés dans la catalyse de la réaction de Henry. Dans un second temps, nous avons développé une stratégie de séparation efficace et applicable à une large gamme de composés en utilisant la technologie des MIPs associées à celle des tags. Notre tag a été formé par réaction de "chimie click" générant ainsi un groupement triazole reconnaissable par un MIP-Tag. Après avoir montré l'efficacité et la sélectivité du MIP-Tag pour une famille de triazoles, l'extraction sélective de la tyrosine taggée d'un mélange d'acides aminés a été réalisée avec une très bonne sélectivité. Par la suite, l'application de notre procédé au recyclage de catalyseurs dérivés de pybox et de proline a été étudiée. Enfin, nous avons montré l'efficacité de notre méthode pour l'élimination de l'oxyde de triphénylphosphine lors d'une réaction de Mitsunobu. La purification d'un milieu réactionnel en SPE au moyen du MIP-Tag a permis l'élimination de 99% de l'oxyde de triphénylphosphine taggé. / This work deals with the use of molecular imprinting technology for the design of new tools in organic sythesis. First, we studied the potential of MIPs in organocatalysis through activation in the imprints. For this purpose, several thiourea-cinchona alkaloid derivatives have been prepared so as to be introduced in the polymer cavities. The use of different MIPs synthesised with these polymerisable catalysts in Henry reaction did not show any advantageous effect on reaction rate or enantioselectivity. Secondly, we have prformed the development of a strategy for separation and recovery of a wide range of compounds by relating tag technology with molecular imprinting. Efficiency and selectivity of MIP-Tag for in triazole series have been demonstrated. Tagged tyrosine has been selectively extracted from an amino-acid mixture. Then, the application of this Tag technology for the recovery of pybox and proline catalyst was investigated. Finally, we have demonstrated the efficiency of our process for the removal of triphenylphosphine oxide formed during a Mitsunobu reaction. The removal of 99% of tagged phosphine oxide was perforrmed by the purification of a reaction medium in SPE by means of MIP-Tag.
7

Redes de producción y crecimiento económico

Tedesco, Lorena F. 03 August 2016 (has links)
Esta investigación contribuye a la discusión acerca de si la red que conforman los sectores productivos de un país determina, en parte, su crecimiento económico. Para ello se ha hecho una revisión bibliográfica de los trabajos teóricos y empíricos más importantes que trataron este tema, circunscribiéndolos a los que utilizaron la matriz insumo producto como herramienta metodológica. Además, se ha aportado evidencia a nivel de país y mundial, que permite analizar la hipótesis de que la arquitectura de la red productiva de un país afecta el crecimiento económico. Para ello se aplicaron modelos iniciales como el de Czamanski y Ablas (1978) hasta más recientes, como el de Acemoglu y otros (2012), y técnicas econométricas como regresiones y análisis de clusters. Finalmente, se desarrolló un modelo teórico de tipo Solow (1956) pero incorporando a los vínculos intersectoriales como determinantes del crecimiento económico, lo que permite medir la respuesta del producto agregado a shocks idiosincráticos en los sectores productivos. / This research contributes to the discussion about whether the network that links the productive sectors of a country determines, in some way, its economic growth. For this we have done a literature review of the most important theoretical and empirical studies that addressed this issue by using the input-output matrix as a methodological tool. In addition, evidence has been provided at country and global levels, to analyze the hypothesis that the architecture of the productive network of a country affects economic growth. To this end we applied initial models such as Czamanski and Ablas (1978) to most recent ones like Acemoglu and others (2012) and econometric techniques such as regression and clusters analysis. Finally, a theoretical variant of the model of Solow (1956) was developed, but incorporating the intersectoral linkages as determinants of economic growth, which measures the response to idiosyncratic shocks aggregate output in the productive sectors.
8

Rauschanalysen am induktiven, kapazitiven und mikrowelleninduzierten Plasma in Kombination mit unterschiedlichen pneumatischen Zerstäubern bei emissionsspektrometrischen Bestimmungen in wäßrigen und organischen Medien

Nehm, Rainer. Unknown Date (has links)
Universiẗat, Diss., 1999--Dortmund.
9

Polymères à empreinte moléculaire pour la détection rapide des résidus de tétracyclines dans le lait

Zouaoui, Hamza January 2007 (has links)
Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal
10

The identification and characterisation of PPIases from Burkholderia pseudomallei and Burkholderia thailandensis

Norville, Isobel Harriet January 2011 (has links)
The aim of this study was to identify and characterise peptidyl-prolyl cis-trans isomerases (PPIases) from the bacterium Burkholderia pseudomallei, the causative agent of the disease melioidosis. The longer term goal was to assess their potential as vaccine candidates or antimicrobial targets. Using bioinformatic approaches, six putative FK506-binding proteins (FKBPs) proteins and three putative parvulin proteins were identified in B. pseudomallei. Of these, six were expressed and purified as recombinant proteins. The purified proteins were used to immunise BALB/c mice, with some providing protection against a subsequent B. pseudomallei infection. These proteins could therefore be proposed as potential vaccine candidates. Homologues of Mip or SurA, which are associated with virulence in other bacterial species, were identified in B. pseudomallei and closely related B. thailandensis. Recombinant Mip or SurA homologues from B. pseudomallei were shown to have characteristic PPIase enzyme activity. To evaluate the role of the Mip homologue from B. pseudomallei in virulence, an unmarked deletion mutant was constructed. The mutant had reduced intracellular survival; defects in putative virulence mechanisms and attenuated virulence in mice. To assess the role of a SurA homologue, closely related B. thailandensis was used as a model organism, with deletion of the gene resulting in defects in intracellular infection, outer membrane integrity and virulence. This indicates that PPIases from B. pseudomallei and B. thailandensis represent novel virulence determinants and potential antimicrobial targets for therapeutics against melioidosis.

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