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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.
31

Uma extensão do teorema de Gauss-Bonnet para superfícies com fins do tipo cone

Branco, Flavia Malta January 1999 (has links)
Neste trabalho definimos as superfícies com fins do tipo cone com coeficiente a 2 >/ 0, uma classe de superfícies completas, não compactas e bem comportadas no infinito, e apresentamos uma extensão do Teorema de Gauss-Bonnet para estas superfícies com coeficiente a > O. / In this work we define a-conical type end surfaces, a 2 >/ O, a class of complete non compact surfaces having a nice behaviour at infinity, and we present an extension of the Theorem of Gauss-Bonnet for these surfaces such that a> O.
32

Uma extensão do teorema de Gauss-Bonnet para superfícies com fins do tipo cone

Branco, Flavia Malta January 1999 (has links)
Neste trabalho definimos as superfícies com fins do tipo cone com coeficiente a 2 >/ 0, uma classe de superfícies completas, não compactas e bem comportadas no infinito, e apresentamos uma extensão do Teorema de Gauss-Bonnet para estas superfícies com coeficiente a > O. / In this work we define a-conical type end surfaces, a 2 >/ O, a class of complete non compact surfaces having a nice behaviour at infinity, and we present an extension of the Theorem of Gauss-Bonnet for these surfaces such that a> O.
33

Uma extensão do teorema de Gauss-Bonnet para superfícies com fins do tipo cone

Branco, Flavia Malta January 1999 (has links)
Neste trabalho definimos as superfícies com fins do tipo cone com coeficiente a 2 >/ 0, uma classe de superfícies completas, não compactas e bem comportadas no infinito, e apresentamos uma extensão do Teorema de Gauss-Bonnet para estas superfícies com coeficiente a > O. / In this work we define a-conical type end surfaces, a 2 >/ O, a class of complete non compact surfaces having a nice behaviour at infinity, and we present an extension of the Theorem of Gauss-Bonnet for these surfaces such that a> O.
34

Solución de problemas relacionados al diseño de superficies complejas: Experiencia de programación en la educación del arquitecto

Herrera Polo, Pablo C., Universidad Peruana de Ciencias Aplicadas (UPC) 10 1900 (has links)
XI Congreso de SIGraDi, 23, 24 y 25 de 2007. Cuidad de México, México. / In this paper, the author explains why architects who know how to use scripts have an advantage over the ones who just know how to manipulate a specific software. The reason behind this affirmation is that knowing how to program frees the architect from the rules and language of the interactive software. To prove his point, the author organized two workshops where students at the school of architecture learned to use Rhinoscript. The students didn’t create a new interface, but used an existing one. They adapted the program (Rhino) to a design problem they had formulated at the beginning of the workshop. Students could have also used MaxScript (3DS Max) and MelScript (Maya).
35

Influência do herbicida Gesapax na atividade microbiana do solo e sua ecotoxicidade /

Régo, Ana Paula Justiniano. January 2017 (has links)
Orientador: Ederio Dino Bidoia / Banca: Marta Siviero Guilherme Pires / Banca: Dejanira de Franceschi de Angelis / Banca: Regina Teresa Rosim Monteiro / Banca: Carlos Renato Corso / Reumo: O herbicida Gesapax® (ingrediente ativo: ametrina) é utilizado em culturas de cana-de-açúcar para o combate a plantas daninhas. Devido as suas propriedades físico-químicas é encontrado com frequência nos corpos hídricos. Ao adicionar surfactantes químicos ao solo contaminado com compostos orgânico, ocorre uma diminuição da tensão superficial entre o contaminante e a fração solúvel do solo, favorecendo a degradação de compostos orgânicos, uma vez que o mesmo fica de maneira biodisponível à microbiota. Dessa forma, neste trabalho teve por objetivo avaliar a influência do herbicida Gesapax na atividade microbiana em amostras de solo, utilizando o surfactante químico Tween 80, como em forma de bioestimulação e adição de consórcio microbiano como forma de bioaumentação, a fim de atuarem como coadjuvantes no processo de metabolização do herbicida. Avaliou-se a atividade microbiana utilizando frascos respirométricos de Bartha e Pramer e utilizando a técnica de colorimetria com DCPIP. Fez-se a análise da biodegradação do herbicida por meio de ensaio de cromatografia (HPLC) em amostras retiradas dos respirometros. Também, avaliou-se a toxicidade do solo com o herbicida através dos organismos testes Saccharomyces cerevisiae, sementes de Lactuca sativa, Eruca sativa e Cucumis sativus, e a mutagenicidade em amostras de solo com a Tradescantia pallida (coração púrpura). Fez-se também a quantificação de bactérias e fungos do solo, finalizando com ensaio de biologia molecular, a fim de avaliar a perturbação da presença do herbicida no solo para a estrutura microbiana nos tratamentos. A adição de surfactante ao solo contaminado com herbicida, possibilitou grande aumento da atividade microbiana, em comparação ao solo controle. O mesmo ocorreu nos tratamentos com ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The herbicide Gesapax® (active ingredient: ametryne) is used in sugarcane crops to combat weeds. Due to its physico-chemical properties it is frequently found in water bodies. By adding chemical surfactants to the soil contaminated with organic compounds, there is a decrease in the surface tension between the contaminant and the soluble fraction of the soil, favoring the degradation of organic compounds, in a bio-available way. Thus, the objective of this work was to evaluate the influence of the Gesapax herbicide on microbial activity in soil samples, using the chemical surfactant Tween 80, as in the form of biostimulation and addition of microbial consortium as a form of bioaumentation, to act as adjuvants in the process of metabolizing the herbicide. Microbial activity was evaluated using Bartha and Pramer respirometric flasks and using the DCPIP colorimetric technique. The biodegradation of the molecule was analyzed by chromatography assay (HPLC) on samples taken from the respirometers. Soil toxicity with the herbicide was evaluated through the test organisms Saccharomyces cerevisiae, seeds of Lactuca sativa, Eruca sativa and Cucumis sativus, mutagenicity in soil samples with Tradescantia pallida (purple heart), quantification of bacteria and fungi soil, finishing with molecular biology assay, to evaluate the perturbation of the presence of the herbicide in the soil to the microbial structure in the treatments. The addition of surfactant to the soil contaminated with herbicide, allowed a great increase of the microbial activity, in comparison to the control soil. The same occurred in the treatments with herbicide and microbial consortium. The herbicide was metabolized in the presence of the surfactant and microbial consortium. There was also an increase in the quantification of the soil microbiota in the presence of these ... (Complete abstract click electronic access below) / Doutor
36

Dinámica de las líneas de curvatura

Ysique Quesquén, Alan 10 November 2016 (has links)
Se estudian las líneas de curvatura de superficies compactas, orientables y conexas del espacio euclidiano. La estrategia consiste en usar las ideas de la Estabilidad Estructural y dar condiciones suficientes para la estabilidad de las líneas de curvatura cuando la superficie se perturba en la topología C3. Para tal efecto se estudia los puntos umbílicos Darbouxiano y sus separatrices, al igual que los ciclos hiperbólicos. La estructura de las líneas principales cerca de estos puntos será establecida, reduciendo su análisis a los puntos hiperbólicos singulares de los campos de Línea en el plano. Con esto se busca crear condiciones para que el conjunto de superficies compactas Σ(a, b, c, d) sea estructuralmente estable y abierto en el sentido C3. / Tesis
37

Srovnání právní úpravy stavby podle současného a nového Občanského zákoníku / Comparison of building legislation according to current and new Civil Code

Popelková, Eliška January 2012 (has links)
Comparison of building legislation according to current and new Civil Code In my master's thesis I focus on building legislation according to the Civil Code. The building, either as a separate thing or part of other things, is mainly the subject of ownership, but also of other civil relations. Therefore it is very widely used and discussed concept. The main goal of the thesis is to describe in detail concept of building in the current Civil Code, with focus on shortcomings and the most problematic areas, and confront it with changes in the new Civil Code. The purpose is also to provide summary of building issues and possible advantages or disadvantages its enactment in the new Civil Code. I mainly concentrate on different division of things and problems with definition of the term building, which apply to specific examples. Last but not least, the thesis evaluates new building enactment and tries to point out problems that may arise in connection with the transition to the principle superficies solo cedit. The master's thesis is, apart from the introduction and conclusion, composed of three chapters. Chapter one is introductory and deals with the principle superficies solo cedit, which is the pivotal principle related to building legislation. Describes its development from Roman law, via ABGB, until...
38

Nanoestructuración de moléculas fotoactivas sobre superficies para la fabricación de sensores de acidez de amplio rango

Martínez Otero, Manuel Alberto 18 June 2010 (has links)
La fabricación de nanoestructuras funcionales moleculares en superficies que puedan actuar como quimio- y biosensores, sistemas de almacenamiento de información o cualquier otro dispositivo tecnológico se ha convertido en un reto de gran interés para científicos y tecnólogos de todo el mundo. El reto es obvio, combinar conocimientos de química, ciencia de superficies, propiedades físicas y técnicas de nanoestructuración para conseguir unos sistemas con tamaños, eficacias y tiempo de respuesta optimizados. Dicho reto es el que se ha querido abordar en esta Tesis Doctoral para contribuir a avanzar en dicho campo junto con las aportaciones de otros muchos grupos. El primer paso fue la elección de los sistemas moleculares adecuados. De las posibles propiedades de trabajo y que pueden exhibir los materiales moleculares, en nuestro grupo de trabajo se ha centrado la atención en las propiedades ópticas, concretamente las de fluorescencia. No obstante no era suficiente estructurar un material molecular ópticamente activo, sino que además éste deberá responder ante un estímulo externo. En otras palabras, el objetivo se centraba en sistemas moleculares que cambian entre dos o más estados con diferentes propiedades de emisión. Esta es una de las condiciones necesarias si se quiere que los dispositivos basados en estos sistemas se conviertan algún día en una realidad. Los estímulos externos que se pueden utilizar para inducir la interconversion de propiedades son diversos, como reconocimiento selectivo de proteínas, analitos o variaciones de pH. En concreto, en esta Tesis Doctoral el interés se ha centrado en el desarrollo de quimiosensores de pH. El uso de estos sistemas de trabajo ha supuesto una plataforma excelente para el desarrollo de nuevas nanoestructuras funcionales así como explorar los límites existentes hoy en día para las técnicas de nanoestructuración. En efecto, en el caso de las nanoestructuras donde la variedad radicaba en los sistemas moleculares, se han utilizado técnicas y metodologías de fabricación bien establecidas. Sin embargo, en otros casos se han abordado auténticos retos como es la fabricación de librerías combinatoriales de tres sistemas moleculares activos diferentes. Esto ha conducido al uso de una técnica litográfica como el "dip pen" hasta las fronteras de los trabajos desarrollados hasta la fecha. De esta manera, esta Tesis Doctoral también supone una contribución muy importante en cuanto a lo que técnicas de fabricación se refiere. Aunque el reto era considerable, la consecución de los objetivos ha supuesto una importante contribución en la frontera del conocimiento en campos como las técnicas de estructuración, comportamiento de materiales en superficies o la fotónica dada la importante involucración de las propiedades de fluorescencia y como varían estas en superficies. Finalmente, no hay que olvidar la importante contribución en el campo de los bio- quimiosensores, dado que todo el conocimiento adquirido puede ser aplicable y de interés no solo para sensores fluorescentes de pH, sino para toda la familia de materiales moleculares. / Fabrication of functional molecular arrays on surfaces that can act as chemo- and biosensors, information storage systems or any other technological device has become an issue of great interest to scientists and technologists worldwide. The main challenge is to combine knowledge of chemistry, surface science, physical properties and nanostructuration techniques to achieve systems with sizes, efficiencies and optimized response times. This challenge is what we have tried to address in this Thesis to contribute to the progress of this field together with many other groups. The first step was to choose the appropriate molecular systems. Of the many properties a molecular material may exhibit, our working group has focused attention on the optical properties, namely fluorescence. But it was not enough to structure an optically active molecular material, it must also respond to external stimuli. In other words, the objective was focused on molecular systems that switch between two or more states with different emission properties. This is one of the necessary conditions for these devices, based on molecular systems, to become a reality someday. External stimuli that can be used to induce interconversion properties are diverse, among then selective recognition of proteins and/or analytes or pH variations. Specifically, in this Thesis, the interest has focused in the development of pH chemosensors. The use of these systems has been an excellent platform for developing new functional nanostructures. They have also allowed us to explore the limits of nanostructuration techniques today. In the case of nanostructures where the variety lay in the molecular systems, well established manufacturing techniques and methodologies have been used. However, in other cases, our group has dealt with real challenges such as the production of combinatorial libraries of three different molecular systems. This has led to the use of a lithographic technique as dip pen nanolithography (DPN) to the borders of the work carried out to date. Thus, this thesis also makes a major contribution in terms of manufacturing techniques are concerned. Although the challenge was considerable, the achievement of the objectives has made an important contribution to the development in such areas as structuration techniques, behavior of materials on surfaces or photonics, given the significant involvement of the fluorescent properties and how they vary on surfaces. Finally, do not forget the important contribution in the field of bio- and chemosensors, since all the knowledge gained may be applicable and of interest not only to fluorescent pH sensors, but for the entire family of molecular materials.
39

Desarrollo y aplicación de sensores para evaluar la contaminación microbiológica de superficies domésticas españolas y de la efectividad desinfectante in situ de productos limpiadores comerciales

González Rivas, Fabián 16 March 2005 (has links)
No description available.
40

Importancia del control higiénico de las superficies alimentarias mediante técnicas rápidas y tradicionales para evitar y/o minimizar las contaminaciones cruzadas

Fuster i Valls, Núria 16 March 2007 (has links)
A pesar de que todavía no existe un documento legal que exija el control microbiológico de superficies, en la mayoría de ambientes del sector alimentario, cada vez más, el sector alimentario es consciente de la importancia que tiene verificar el plan de limpieza y desinfección. Así, los programas de limpieza y desinfección se diseñan con el objetivo de reducir, y en algunos casos, eliminar la carga bacteriana y restos de materia orgánica e inorgánica de las superficies alimentarias. De esta forma, se pretende minimizar el riesgo de contaminación cruzada para garantizar un producto seguro y de calidad. Actualmente, un factor a considerar en el diseño del plan de higienización es la eliminación de unas estructuras denominadas biofilms, las cuales, no se habían tenido en consideración hasta que no se han desarrollado sistemas que permiten realizar su detección.Tanto es así que en los últimos años ha ido creciendo el interés en la investigación, desarrollo y/o mejora de técnicas rápidas, fiables y sencillas para evaluar la contaminación de superficies. Sin embargo, el conocimiento acerca de su validez en el uso industrial práctico es todavía escaso. Este trabajo describe y compara técnicas tradicionales y rápidas para evaluar la contaminación microbiológica en superficies y la formación de biofilms en condiciones experimentales, especialmente este estudio se ha llevado a cabo con microorganismos alterantes y patógenos como L. monocytogenes y posteriormente y con la experiencia adquirida, se ha llevado a cabo un estudio de monitorización y establecimiento de límites críticos en una industria alimentaria. Además, el trabajo destaca la importancia de aislar los microorganismos del ambiente industrial y las posibilidades y perspectivas de futuro para utilizar las técnicas descritas en el ambiente industrial como herramientas de verificación de la limpieza y control de superficies.Por otra parte, este trabajo recoge la experiencia adquirida durante tres meses en el extranjero en la cual se evaluó la eficacia distintas sustancias antimicrobianas sobre piel de animales para su posible implantación dentro de los métodos de descontaminación de canales que se están regulados en Estados Unidos de América. / Despite there is not a legal document demanding a microbiological control of surfaces, the concern on the importance of monitoring its hygiene sanitation is growing among most of alimentary industries. Consequently, most sanitation programs are designed to reduce, or even eliminate, the microbial contamination, and organic food debris of food surfaces. This measure is meant to minimize the recontamination risk to guarantee a safety product. Nowadays, a factor to take into account to design sanitation programs is a microbial community called biofilm which was omitted in the past until efficient tools to detect it were developed.Therefore there is growing interest in research and development of novel tools to study, detect, and characterize microbes and biofilms in industrials environments. However, knowledge about their validity in practical industrial use is still scarce. This dissertation describes and compares traditional and rapid methods used to evaluate surface microbial contamination in laboratory conditions, later - using the acquired experience - a study of monitoring and microbiological criteria for food industry has been implemented. In addition the study addresses the importance of isolating microorganisms from industrial environment in order to reach more effective sanitation programs.On the other hand, this dissertation describes the experience acquired during several months in the United States of America. During this research stage, the efficacy of several decontamination substances was evaluated on animal hides for its implementation in the regulated American decontamination carcasses.

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