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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.
101

Simetrias planas e alguns problemas de ladrilhamento

Silva, Aguinaldo Manoel January 2013 (has links)
Orientador: Armando Caputi / Dissertação (mestrado) - Universidade Federal do ABC, Mestrado Profissional em Matemática em Rede Nacional - PROFMAT, 2013
102

Amortecimento superficial nos sistemas de micro-drenagem em regiões de baixa declividade. / Peak flow reduction for micro-drainagem systems applied to flat areas.

Atila Csobi 20 April 2011 (has links)
O presente trabalho desenvolve uma proposta para a avaliação da redução da vazão de pico do hidrograma do método racional, no contexto de bacias hidrográficas topograficamente planas. Entendem-se como planas aquelas localidades, cujas declividades médias características e/ou projetadas são inferiores a 0,5%. Pretende-se também neste trabalho apresentar metodologias e práticas de projeto de drenagem usualmente adotadas em regiões de características topográficas semelhantes. No desenvolvimento do estudo, foram discutidas as bases teóricas do Método Racional e outros métodos de avaliação hidrológica que procuram levar em conta o amortecimento da vazão durante o seu escoamento sobre o leito das vias. Apresentam-se também as bases científicas para a criação de um modelo hidrodinâmico a ser usado no estudo para a determinação do fator de redução da vazão de pico do hidrograma racional. A capacidade de escoamento em vias urbanas é então discutida, de forma a se justificar as relações criadas como conclusão do trabalho. O resultado final apresentado é o estabelecimento de uma relação entre a variação do pico da vazão do Método Racional, com a capacidade de armazenamento ou amortecimento de cheias existente nessas vias. Relações estas que, para fins práticos, significam tanto o incremento positivo no período de retorno do projeto, quanto a redução da vazão para efeito de dimensionamento de galerias. Tais resultados são demonstrados de forma prática por meio do estudo de caso no município de Praia Grande, o litoral sul paulista. / This work presents a proposal for estimating the reduction of the Peak Flow Rate determined by the Rational Method, considering flat basins as a main characteristic. It is considered flat, all of those basins in which the average slope on the streets are smaller than 0,5 %. It is also intentions of this work discuss methods and practices adopted to flat areas as urban drainage solutions and best management practices. Within this work, we also present all the theoretical basis of the Rational Method, among others, that try to fuse the street storm water storage capacity whit the conveyance capacity of a usual street. It is also presented theoretical basis of hydrodynamic models to be used as the main tool to determine de peak flow reduction factor of the Rational Method Hydrogram. Conveyance capacity of a usual street is discussed, street storm water conveyance capacity is also discussed in order to justify the relations proposed as a conclusion of this work. As a result of this work it is established a relationship between the Peak flow rate determined by the Rational Method and the street storm water storage capacity. In addition, this peak reduction can be used as a positive increment on the Recurrence Interval or as flow rate reduction when designing the sewerage system, which means implementation costs reduction. An application to the city of Praia Grande, located the Sao Paulo State, is presented and used as a case of study.
103

Physico-chemical properties of polymers at interfaces

Díez Orrite, Silvia 16 December 2002 (has links)
A polymer is a large molecule constructed from many smaller structural units calledmonomers joined together by covalent bonds. Polymers have existed in natural formsince life began and those such as DNA, RNA, proteins and polysaccharides are someof the most important macromolecules found in plant and animal life. From the earliesttimes, the man has used many of these polymers as materials for providing clothing,decoration, tools, weapons and other requirements. However, the origins of today'spolymer industry commonly are accepted as being in the nineteenth century whenimportant discoveries were made concerning to the modification of certain naturalpolymers, as cellulose. The use of synthetic and natural polymers as stabilisers forcolloid systems (sols, dispersions, microemulsions, etc.) is becoming more importanteveryday in contemporary life. Polymer additives can be applied in preconcentrationsand dehydration of suspensions in mineral processing, purification of wastewater andeven in nutritional and pharmaceutical emulsions being their importance related to thecharacteristics of the process and the properties that they show. The present work aimsto develop appropriate numerical and analytical modelling techniques, which candescribe (considering the formation of loops and tails) the structure of a polymeric layeradsorbed on heterogeneous surfaces; this adsorbed layer is an relevant factor in theproperties showed by this kind of materials. Taking into account this, the methodologyknown as Single Chain Mean Field (SCMF) (originally used to study micellaraggregates and grafted polymers) was modified to apply on polymer adsorptionproblems. In this way, it was possible to calculate numerically properties that can beexperimentally measured, such as total monomer volume fraction profiles, loop and tailvolume fraction profiles, adsorbance or the thickness of the adsorbed layer. Thestructure of the polymeric layer was examined both for flat and spherical (colloidalparticles) surface geometries. When compared with other well establishedmethodologies for the numerical simulation of polymeric systems, this new version ofSCMF was found to be more efficient due to the improved sampling of the polymerchain configuration space.Thus, SCMF method results, in the case of the adsorption on flat surfaces, compare wellwith those obtained either with Monte Carlo simulations or with the method developedin the 80s by Scheutjens and Fleer (SCF). Due to the lack of studies focusing to polymeradsorption on colloidal particles, our results have been the first to present quantitativepredictions of the structure of the polymeric layer adsorbed on a spherical surface. Thus,we have demonstrated the dependence of the adsorbed polymer layer with the size ofthe colloidal particle as well as the characteristic lengths that influence on it. Finally, inthis work an analytical approach for the description of polymer-colloidal mixtures hasbeen developed which compares well with the numerical results obtained from theSCMF methodology. Furthermore, the analytical approach is able to predict systembehaviours, as for example the formation of gels. / Un polímero es una molécula de grandes dimensiones formada de pequeñas unidadesllamadas monómeros, los cuales se encuentran unidos por medio de enlaces covalentes.Los polímeros han existido de forma natural desde el comienzo de la vida, y aquelloscomo el DNA, RNA o las proteínas son algunos de los polímeros más importantesencontrados tanto en la vida animal como en la vegetal. Desde siempre el hombre hautilizado muchos de estos polímeros como materiales para hacer ropa, decoración,herramientas, etc. Sin embargo, el origen de la industria de polímeros que conocemoshoy en día se produjo en el siglo 19, gracias a importantes descubrimientos dentro de lamodificación de ciertos polímeros naturales, como la celulosa. El uso de polímerossintéticos y naturales como estabilizadores de sistemas coloidales (dispersiones,microemulsiones, etc.) juega en nuestros días un papel importante. Los polímerosutilizados como aditivos, pueden ser aplicados en preconcentraciones y deshidrataciónde suspensiones dentro de procesos minerales, tratamiento de aguas residuales e inclusolos podemos encontrar dentro de la industria farmacéutica y alimentaria, donde suimportancia es debida a la procesabilidad y propiedades que ellos exhiben. El trabajoque se presenta es orientado al desarrollo de técnicas de modelización, tanto analíticascomo computacionales, y su aplicación en la descripción (por medio de la formación debucles y colas) de la estructura de la capa de polímeros adsorbida en superficiesheterogéneas, siendo dicha capa de polímeros un factor importante en las propiedadesque este tipo de materiales presentan. Con este propósito, la metodología conocidacomo Single Chain Mean Field, utilizada anteriormente tanto para el estudio deagregados micelares como de polímeros anclados en superficies, ha sido modificadapara describir la adsorción de polímeros en superficies. Así se han podido calcularnuméricamente propiedades medibles experimentalmente como los perfiles de lafracción en volumen de monómeros totales, además de los pertenecientes a los bucles ycolas, adsorbancia o el espesor de la capa adsorbida, para geometrías de la superficieabsorbente tanto plana como esférica (partículas coloidales). En su comparación conotras metodologías, ya establecidas para la simulación numérica dentro de la física depolímeros, la aplicación de esta nueva versión del Single Chain Mean Field (SCMF)ha resultado ser más eficiente debido a un mejor muestreo del espacio deconfiguraciones de las cadenas poliméricas. De este modo, comparando los resultadosobtenidos a partir del SCMF, con aquellos obtenidos mediante técnicas de simulaciónMonte Carlo o la teoría desarrollada en los años 80 por Scheutjens y Fleer (SCF), se hapodido encontrar un buen acuerdo en las propiedades calculadas para el caso de laadsorción en superficies planas. Debido a la dificultad intrínseca del estudio de laadsorción en superficies curvadas, nuestros resultados son los primeros que presentanpredicciones cuantitativas sobre la estructura de la capa que se forma sobre unapartícula coloidal. Así hemos podido comprobar la dependencia de la estructura de lacapa de polímeros adsorbidos con el tamaño de la partícula sobre la que se encuentranadsorbidos además de las longitudes características de las cuales depende. Finalmente,en este trabajo se ha desarrollado, también, una teoría analítica para la descripción de lamezcla polímero-coloide. De este modo, los resultados numéricos obtenidos con elSCMF han podido ser comparados con dicha teoría, obteniendo, de nuevo, un buenacuerdo y predecir, además, comportamientos colectivos como la formación de geles.
104

Filosofijos ir kūrybos santykis G. Deleuze'o postfilosofijoje / Relationship between philosophy and creation in G. Deleuze postphilosophy

Junutytė, Laura 23 May 2005 (has links)
This master work analyzes relationship between philosophy and creation developed in the works of Gilles Deleuze. This French philosopher thinks in postnietzschean paradigm. He develops philosophy of becoming, taken from Nietzsche. Deleuze rejects thinking of identity, saying that creation is the first princip, whereas identity is the second. He uses the idea of overturned Platon, so his main purpose is to open new perspectives of thinking. Another aspect of difference is considered with Felix Guattari by model of rhizome, what pressupose an open system in mind and in philosophy, too. Creation in philosophy involves three great aspects: creation of concepts, setting up the plane of immanence, inventing conceptual personae. As Deleuze and Guattari insists, philosophy is not contemplation, reflection or communication, but creation of concepts, that are always new. Concepts a not given; it must be created. Concepts opens and acts onto the plane of immanence, what means that philosophy must act only immanently, without any trancendent pressupposition. The conceptual personae produces the plane of immanence and gives to the concepts their specific force. Otherwise, inventing of conceptual personae shows the relationship between philosophy and experience of philosopher or what mode of existence every thinker invents. Creation in philosophy requires experimentation and good taste. There is no abstract thruth: every thruth is created and acts only immanently. Deleuze and Guattari... [to full text]
105

Technologinių vamzdynų kokybės užtikrinimo analizė / Analysis of technological pipeline quality assurance

Adomavičiūtė, Irma 29 June 2007 (has links)
Baigiamajame magistro darbe nagrinėjamos technologinių vamzdynų kokybės vertinimo problemos, kokybės užtikrinimo būtinumas ir priemonės tam tikslui pasiekti. Išnagrinėtas kokybės sąvokų supratimas įvairiose šalyse, pateikiami ISO serijos standartų privalumai ir minusai įmonėse, siekiančiose kokybės tobulėjimo. Išanalizuota užsienio šalių patirtis technologinių vamzdynų tiesimo bei eksploatavimo srityse. Remiantis sprendimų paramos sistemomis išanalizuotos dvi technologinių vamzdynų tiesimo alternatyvos ir parinktas racionalus variantas. Siekiant įvertinti technologinių vamzdynų kokybę, peržvelgus įvairias rekomendacijas, standartus, įstatymus, sudarytas kokybės kontrolės planas. Pateikiamos baigiamojo darbo išvados. / Master’s thesis analyzes issues of technological pipeline quality evaluation, assurance and means to achieve it. It analyzes various understandings of quality issues in several countries, provides ISO quality standard‘s advantages and disadvantages in companies who are seeking to improve their quality. Experience of various countries is analyzed and compared in construction and utilization of technological pipelines. Based on decision support systems two alternatives for construction of technological pipelines are analyzed and an optimum solution is chosen. During evaluation of quality of technological pipelines, various recommendations, standards and laws were evaluated. A plan of measures to control quality is suggested. Final practical implications are provided in conclusions of the thesis.
106

Turizmo plėtros galimybės Biržų rajone / Opportunities of tourism development in Biržai region

Ramutėnaitė, Martyna 05 July 2011 (has links)
Darbo objektas - turizmo plėtra Biržų rajone. Problema: Kokios yra turizmo plėtros galimybės Biržų rajone? Darbo tikslas - ištirti turizmo plėtros galimybes Biržų rajone. Darbo uždaviniai: 1. Išanalizuoti turizmo plėtrą teoriniu aspektu; 2. Įvertinti turizmo situaciją Biržų rajone; 3. Numatyti turizmo plėtros galimybes Biržų rajone. Darbas susideda iš trijų pagrindinių dalių. Pirmoje dalyje pateikta medžiaga apie turizmo plėtrą, darniosios turizmo plėtros ir tvaraus turizmo ypatumus, strateginio planavimo elementus bei modelius, padedančius skatinti turizmo plėtrą. Antroje dalyje apžvelgiama tyrimo metodika ir organizavimas, tyrimo instrumentas, tiriamųjų kontingentas. Trečioji – tiriamojo darbo dalis, kurioje analizuojamos Biržų rajono turizmo plėtros galimybės remiantis atliktos anketinės apklausos duomenimis. Taip pat išnagrinėta dabartinė Biržų rajono turizmo situacija bei atlikta turizmo plėtros galimybių Biržų rajone SSGG analizė. Remiantis moksline literatūra bei atlikto kiekybinio tyrimo rezultatais pateikiama suformuota turizmo plėtros galimybių Biržų rajone schema. Be to pasiūlytas projektinis turizmo plėtros Biržų rajone pasiūlymas – kaimo svečių namų „Ramybė“ verslo planas. Taip pat išanalizuoti turizmo plėtros projekto efektyvumo vertinimo metodai. Išvadose apibendrinami pagrindiniai teoriniai sprendimai, tyrimo bei anketavimo rezultatai. / -.
107

Konsultavimo vaidmuo rengiant savivaldybių strateginius plėtros planus / The role of consulting in designing municipal strategic development plans

Leščinskaitė, Lina 31 May 2005 (has links)
The aim of the thesis: to design the model of the consulting process of the preparation of development plans of municipalities and recommendations for the improvement of the advisory process of the preparation of development plans of municipalities. Tasks: 1. To carry out the theoretical analysis of the organisation of the development plan designing process and establish the main problems of practical designing as well as the defects of the organisation of this process; 2. To analyse the theoretical methods of consultation organisation and their place in the preparation of municipal development plans; 3. To carry out the analysis of the advisory process of the preparation of municipal development plans; 4. By employing a questionnaire survey, to find out the opinion of representatives from municipalities on the issues of consultations on the preparation of strategic development plans; 5. On the basis of the theoretical and practical researches, to establish the role of a consultant in the preparation of strategic development plans of municipalities and submit a summarised model of the advisory process concerning the preparation of development plans as well as recommendations for the improvement of this process. Research object of the paper is the advisory process of the preparation of strategic development plans of municipalities. During the process of research, material on the role of consulting in preparing development plans was collected from municipalities and analysed... [to full text]
108

Espalhamento de ondas acústicas em defeitos topológicos / Scattering of acoustic waves in topological defects

Ribeiro, Átila Pereira 21 November 2016 (has links)
Research on topological defects has been of increasing interest in recent years, since no laboratory-produced crystal is perfect, that is, it will always present a remarkable number of defects in its structure. Topological defects have different names that depend particularly on the symmetry breaking of the system. Thus, in this work we investigate the acoustic scattering by rigid scatter included in media with topological defects such as declination and global monopole. For these media the acoustic scattering by solid scatter and isotropic included in liquid crystals in the nematic phase with disclination as well as global monopole defects were investigated. In these systems, the amplitude and the scattering patterns were computed as well as the cross section. The results revealed that for low frequencies and < 1 the backscattered wave is dominant, however for values of > 1 the spread wave becomes dominant, where is the default parameter. For high frequencies, when the value of approaches to 0.1 we found that the backscattered wave becomes dominant. We conclude that both the disclination and the global monopoles media have a great advantage in the use in devices that make use of acoustic wave scattering because of the large amplitudes that can be achieved using these cylindrical and spherical structures included in defective fluids. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / As pesquisas em defeitos topológicos têm apresentado um interesse crescente nos últimos anos, visto que nenhum cristal produzido em laboratório é perfeito, ou seja, ele sempre apresentará um notável número de defeitos em sua estrutura. Os defeitos topológicos apresentam diferentes nomes que dependem particularmente da quebra de simetria do sistema. Assim, neste trabalho investigamos o espalhamento acústico por espalhadores rígidos inclusos em meios com defeitos topológicos tais como desclinação e monopolo global. Para estes meios foram investigados o espalhamento acústico por espalhadores sólidos e isotrópicos inclusos em cristais líquidos na fase nemática com desclinação bem como defeitos de monopolo. Nestas sistemas, foram computados a amplitude e os padrões de espalhamento bem como a seção de choque. Os resultados reveleram que para baixas frequências e < 1 a onda retroespalhada é dominante, porém para valores de > 1 a onda espalhada se torna dominante, onde é o parâmetro de defeito. Para altas frequências, quando o valor de se aproxima de 0.1 verificamos que a onda retroespalhada passa a ser dominante. Concluímos que tanto os meios com desclinação quanto os monopolos globais apresentam uma grande vantagem na utilização em dispositivos que fazem uso de espalhamento de ondas acústicas em razão das grandes amplitudes que se pode alcançar utilizando essas estruturas cilíndricas e esféricas inclusas em fluidos com defeitos.
109

Curvas planas : clássicas, regulares e de preenchimento

Maia, Francisco Everton Pereira January 2016 (has links)
Orientador: Prof. Dr. Vinicius Cifú Lopes / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Mestrado Profissional em Matemática em Rede Nacional, 2016. / Neste trabalho apresentaremos uma visão sobre os princípios das curvas planas. Iniciamos o desenvolvimento dos estudos com as cônicas: parábola, elipse e hipérbole que são aplicadas no Ensino Médio normalmente usando equações cartesianas. Abordaremos o assunto destas e outras curvas usando equações paramétricas, com intuito de mostrar a vantagem de utilizá-las. Abrangeremos em nossos estudos a catenária, a cicloide e a curva de Bézier, curvas as quais não são estudadas no Ensino Básico, mas poderiam ser apresentadas como um desafio motivador ao estudo da Matemática, explorando suas várias aplicações que acontecem de maneira natural em nosso cotidiano. Apresentaremos propriedades gerais das curvas como: continuidade, parametrização, comprimento de arco, curva suave, curvatura e outras, além de realizar a demonstração do teorema fundamental das curvas planas e para finalizar estudaremos uma curva exótica, conhecida como curva de preenchimento de espaço, construída pela primeira vez pelo matemático italiano Giuseppe Peano. / In this work we will present an insight into the principles of flat curves. We start with the conics: parabola, ellipse and hyperbole which are applied in high school usually using Cartesian equations. We will discuss those and other curves using parametric equations, in order to show the advantage of using them. We will cover in our studies the catenary, the cycloid and a Bézier curve, curves which are not studied in basic education, but could be presented as a challenging motivation to the study of Mathematics by exploring their various uses that happen naturally in our everyday lives. We will introduce general properties of curves as: continuity, parameterization, arc length, smooth curve, curvature and others, in addition to the proof of the fundamental theorem of plane curves, and finally we will study an exotic curve, known as space-filling curve, built for the first time by the Italian mathematician Giuseppe Peano.
110

Curvas planas: uma visão para o ensino médio

Cardim, Breno da Silveira 04 July 2014 (has links)
Submitted by Viviane Lima da Cunha (viviane@biblioteca.ufpb.br) on 2015-06-02T14:42:10Z No. of bitstreams: 1 arquivototal.pdf: 4771282 bytes, checksum: 54ad9700566c303ef32a4f565e89ee2c (MD5) / Approved for entry into archive by Viviane Lima da Cunha (viviane@biblioteca.ufpb.br) on 2015-06-03T22:27:07Z (GMT) No. of bitstreams: 1 arquivototal.pdf: 4771282 bytes, checksum: 54ad9700566c303ef32a4f565e89ee2c (MD5) / Made available in DSpace on 2015-06-03T22:27:07Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 4771282 bytes, checksum: 54ad9700566c303ef32a4f565e89ee2c (MD5) Previous issue date: 2014-07-04 / In this work, we study the principles of the theory of plane curves, within the context of high school / Neste trabalho estudamos os princípios da teoria das curvas planas, tendo em mente, estudantes do ensino médio. Aqui, é proposta uma introdução ao Cálculo Diferencial e Integral àqueles estudantes, e em seguida um estudo sobre a teoria das curvas, onde alguns exemplos clássicos são apresentados, bem como, conceitos como vetor tangente, área e comprimento de curvas são discutidos.

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