• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 374
  • 76
  • 72
  • 58
  • 38
  • 27
  • 17
  • 10
  • 5
  • 5
  • 4
  • 4
  • 3
  • 3
  • 3
  • Tagged with
  • 867
  • 145
  • 126
  • 60
  • 52
  • 50
  • 46
  • 43
  • 40
  • 39
  • 39
  • 39
  • 38
  • 37
  • 37
  • 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.
571

Corridors in Conservation and Philosophy

Benton, Christine S. 08 1900 (has links)
My thesis focuses on philosophical themes implicit in corridor conservation, using the Big Thicket National Preserve as an example. The way in which corridors, boundaries and communities are ambiguous, as both limits and connections, is dealt with. Corridor-patch matrices assemble ecological and human groups into temporary communities, often with conflicting interests. Such constellations foreground how a foreigner's boundary crossing is a notion important to both conservation and a philosophical study of being, seen as being always in relation with otherness. In this context, the notion of foreignness and Jean-Luc Nancy's idea of being-with is explored. Understanding the complex network of relations in which an entity exists leads to an awareness of its ambiguous nature. To facilitate judgment with such ambiguity, one needs a contextual understanding of a situation.
572

Defect characterisation in multi-crystalline silicon

Lotharukpong, Chalothorn January 2015 (has links)
Electron beam induced current (EBIC) and atom probe tomography (APT) were used in this study to determine electrical activities and impurity compositions at extended defects in multicrystalline silicon (mc-Si) samples. The results provide, for the first time, information regarding the chemical species present at defects whose electrical activity has previously been measured. A new APT specimen fabrication process was developed with the ability to select a specific defect for APT analysis. Development of the APT specimen fabrication process proceeded by first selecting and optimising the preferential etching for nano-scale defect delineation. Three etchants were evaluated, namely Secco, Sirtl and Dash, from which the Secco etch was selected. Three parameters were optimised to produce etch pits with geometries that meet the requirements imposed by APT specimen fabrication methods. The optimum parameters were 0.05M potassium dichromate concentration, 20°C etch temperature, and 30sec etch time. In the second stage, marking techniques were developed in order for the defects to be located throughout the APT specimen fabrication process. However, it became apparent that the conventional APT specimen fabrication method could not be used to fabricate APT specimens containing selected defects in a mc-Si sample. This led to the development of a novel APT specimen fabrication approach which allowed APT specimens to be fabricated, reproducibly, containing grain boundaries and isolated dislocations. In order to evaluate accurately iron contamination in mc-Si, four atom probe parameters were optimised to maximise detection sensitivity: the evaporation rate, the laser beam energy, the pulse repetition rate and the specimen temperature. The optimisation process can be divided in to two parts. In the first part, a matrix of pre-sharpened single-crystal silicon specimens was subjected to a variety of experimental parameters. The optimised parameters were determined to be 0.3% evaporation rate, 0.5nJ beam energy, 160kHz repetition rate and 55K specimen temperature. The second part was to determine the iron detection efficiency –the percentage of detected Fe ions that can be correctly identified as Fe– and sensitivity using these parameters to analyse a specially prepared iron calibration specimen. The values were determined to be a detection efficiency of about 35% and sensitivity of 54ppm or 2.70x10<sup>18</sup> atom/cm<sup>3</sup>. The APT specimen fabrication process and the optimised APT analysis parameters were used to analyse four extended defects in mc-Si samples subjected to three different processing conditions, namely gold-contaminated, as-grown and phosphorus diffusion gettering (PDG). The important aspects of the analysis are listed below: • Gold was not detected at the grain boundary and its associated dislocations in the gold-contaminated specimen. The binding enthalpy of gold to such defects is thus less than 0.63eV. • Iron was not detected in any specimen. • Copper was observed at the grain boundary in the as-grown specimen in the form of individual atoms as well as clusters with diameters ranging between 4nm and 9nm. The electrical activity of the grain boundary was about 58%. • Nickel and carbon were detected at the grain boundary in the post-PDG specimen with the former having platelet structures with diameters and thicknesses ranging between 4nm-7nm and 2nm-4nm, respectively. The recombination strength of the defect was about 22%. • Two nickel clusters were found at the isolated dislocation in the post-PDG specimen. The clusters were spherical with an average diameter of 10nm. The distance between the two clusters was 35nm. The recombination strength of the defect was about 4%.
573

D'herbe, de terre et de sang : la Cerdagne du XIVe au XIXe siècle / Grass, land and blood bonds : cerdanya in the modern era (14th – 19th c.)

Conesa, Marc 30 November 2010 (has links)
Cette recherche doctorale porte sur la relation des sociétés aux territoires qu’elles construisent dans une perspective diachronique. Je fais l’hypothèse que le rapport à l’espace participe de la classification des individus en plusieurs groupes, selon la résidence, le statut familial ou la richesse en terre. Cette série ne saurait être considérée comme ni exhaustive ni ahistorique. Dans cette perspective, la Cerdagne (Pyrénées de l’Est) est apparue comme un terrain idoine compte tenu des lignes de fracture, sociale et spatiale, qui révèlent et recomposent les différents rapports à l’espace entre le XVIe et le XIXe siècle. Trois questionnements envisagés à trois échelles différentes se sont posés. À petite échelle, l’apparition d’une frontière politique au milieu du XVIIe siècle (traité des Pyrénées, 1659) modifie-t-elle les rapports à l’espace en créant un nouvel horizon étatique ? Et quelle place tient la ville de Puigcerdà dans la structuration de ces sociétés de montagne ? A l’échelle des communautés d’habitants, quels types de rapport à l’espace se noue autour de l’accès aux biens collectifs tant au niveau intercommunautaire qu’intracommunautaire ? Enfin, à grande échelle, quels rapports se créent et se recréent entre les familles, les individus et la terre dite « privée », alors que du point de vue historiographique, la Cerdagne se situe dans une aire pyrénéenne marquée par la primogéniture et l’exclusion des puînés de l’héritage foncier. / This doctoral research dwells on the relationship between societies and the territories they shape within a diachronic perspective. The hypothesis at the core of this work is that the relation to space partakes of the classification of the individuals into several groups, according to localities, family status or land wealth. This list is neither to be considered exhaustive nor ahistorical. From this perspective, Cerdanya (in the Eastern Pyrenees) qualified as a terrain, given the social and spatial divides which bring to the fore and reconstruct the manifold relations to space between the 16th and 19th centuries. Three questions arise at three different scales. On a small scale, does the coming upon the political scene of a frontier in the middle of the 17th c. (with the Treaty of the Pyrenees, 1659) modify the relations to space by creating a new state, a new actor ? Then, what about the role held by the city of Puigcerdà in the shaping of these moutain societies ? On the community scale, what kinds of relations to space form when it comes to common lands as much on the intercommunal as the intracommunal level ? Lastly, on the large scale, what are the links weaving between families, individuals and the land called “private”, when, from a historiographical point of view, Cerdanya is located in a Pyrenean aera where primogeniture and the exclusion of the youngest is deeply rooted.
574

Naše menšiny (později Naše hranice), meziválečný časopis podporující českou menšinu v národnostně smíšených oblastech severovýchodních Čech / Naše menšiny /our minorities (later Naše hranice/Our boundaries), an intewar journal supporting the Czech community in the nationally mixed regions of southeast Bohemia

Štěpánová, Marie January 2015 (has links)
"Our Minorities (later Our Boundaries), an interwar magazine supporting Czech minority in nationally mixed regions of Nord-East Bohemia" presents for the first time a longer embracive characterization of a First Republic periodical, seated in Malé Svatoňovice, and published between 1920-1938 (XVII and XVIII volumes already as Our Boundaries). This thesis uses a method of historical analysis and besides of information about publishing, personalities connected with this monthly paper (particularly J. M. Vlček) and contents of sections, recognizing how this already not very known regional serial wanted to support Czech minorities in a mainly German speaking borderline area.
575

Levesonova komise a její význam pro diskusi o etických hranicích bulvárních médií / The Leveson Inquiry and Its Value for the Discussion about Ethical Limits of Tabloid Media

Roubková, Janetta January 2016 (has links)
This thesis deals with the use of dishonest manners of obtaining information, particularly in connection with the tabloid media. The aim is to evaluate the practices of the tabloid media in gathering information and contribute to the discussion about their ethical borders. It also analyzes investigation of Leveson Inquiry, which was established in 2011 by the British government in response to the phone-hacking scandal connected with tabloid newspaper News of the World. The judicial commission leded by Brian Leveson was tasked to examine the ethical aspects of media and to find out if the system of media self-regulation is still effective. The thesis also includes an analysis of the tabloid environment in the Czech republic. It is based on interviews with representatives of major tabloids in this country.
576

La Guyane et le Brésil, ou la quête d'intégration continentale d'un département français d'Amérique, les enjeux d'une cooperation transfrontaliere nord-sud / French Guiana and Brasil, Or the Quest for a Continental Integration Of A French Department In America

Granger, Stéphane 16 May 2012 (has links)
L’objectif général de ce travail est d’expliquer la nature des relations particulières entre une région française d’Amérique du Sud, la Guyane, et le Brésil, que l’histoire coloniale a rendus frontaliers, au moment où dans un contexte général d’intégrations continentales s’amorce entre eux un rapprochement institutionnel mettant un terme à quatre siècles de rivalités et d’ignorance réciproque. Mais la Guyane subit une forte pression migratoire et environnementale de la part d’un Brésil particulièrement dynamique, ainsi que les contraintes d’une appartenance française et européenne perçue comme étouffante en dépit des avantages qu’elle procure. En pleine quête identitaire, elle aimerait s’intégrer à un environnement géopolitique que le Brésil cherche de son côté à organiser à son profit dans sa stratégie d’affirmation continentale. Au moment où se construit un pont sur l’Oyapock entre les deux voisins, les récents accords de coopération régionale visent à une "continentalisation" de la Guyane, dans une Amérique du Sud dans laquelle elle était jusque là peu intégrée, mais elle doit se débattre entre de multiples enjeux régionaux, nationaux voire supranationaux qui la dépassent. / The overall objective of this paper is to explain the nature of the special relationship between a French region of South America, French Guiana, and Brazil that colonial history made neighbors, at the time when in a general context of continental integration these two countries are starting to knit closer institutional links putting an end to four centuries of rivalry and mutual ignorance. But French Guiana is undergoing high migration and environmental pressure on the part of a particularly dynamic Brazil, as well as the constraints of a french and european membership felt as choking in spite of the benefits it provides. In the midst of its search for its own identity quest, French Guiana would like to integrate into a geopolitical environment than Brazil on its side seeks to organize to its benefit, as part of its strategy for continental assertion. At the time when a bridge over the Oyapock river between the two neighboring is being built, recent regional cooperation agreements are aimed at "continentalization" French Guiana, in South America which it has so far been little integrated, but it must struggle between of multiple regional, national or supranational issues, which it is far too small.
577

Stroller Service System : How to make customer products sustainable within the planetary boundaries - using the case product ‘stroller’, PSS and a Design Thinking approach

Thorslund, Gustav January 2019 (has links)
Physical customer products have an environmental impact, such as greenhouse gas emissions, due to the use of virgin resources from cradle-to-grave, especially when the origin of the material is from fossil resources. This thesis aims to create a circular business model, by investigating the product ‘stroller’ and place it in a Product Service System, where the user subscribes to the Stroller Service System. This means that the product gets a service function: ‘transportation of a child’, mapped with a user-centered approach. The main objective is to lower the ecological footprint by adopting a modular design including bio-based material and stainless steel, and also include services to address economical and social sustainability goals. The methodology that is used is divided into two parts: Status Analysis – which consists of stroller related literature study, literature review and case study, and the second part is the Design Process – creating the product-, service- and system design. The results are grounded in user insights, life cycle assessment and co-creation with experts, where the conclusions are that a PSS Model Stroller should be used by 4-6 users which translate to about 15-20 years of usage for the steel layer. The way of refurbishing the strollers is done by contract workers that exist where the users exists, i.e. Ease Stroller Hub, who change the bio-based material in-between the use-phases and hands over the refurbished stroller to the next user. Add-on services of access to car pools and grocery delivery is included in the system to ease the stroller user’s everyday life and is a way to designing out the need of owning a car, to lower the overall environmental impact.
578

Método dos elementos finitos com fronteiras imersas aplicado a problemas de dinâmica dos fluidos e interação fluido-estrutura. / The finite element method with immersed boundaries applied to fluid dynamics and fluid-structure interaction problems.

Gomes, Henrique Campelo 20 March 2013 (has links)
Este trabalho pode ser dividido em três etapas principais. Inicialmente é proposta uma formulação estabilizada do método dos elementos finitos (MEF) para solução de problemas de escoamento incompressível governado pela equação de Navier-Stokes. Esta formulação foi implementada em um código computacional e testada através de diversos exemplos numéricos. Alguns elementos finitos com diferentes pares de função de interpolação da velocidade e pressão, consagrados na literatura, e também elementos finitos menos populares, foram investigados e seus resultados e performance comparados. A segunda etapa consiste na formulação do problema estrutural. Buscou-se por uma formulação dinâmica, não linear, capaz de simular movimentos complexos de estruturas sujeitas a grandes deslocamentos e grandes deformações durante longos intervalos de tempo. A etapa final deste trabalho é a proposição de um método para solução de problemas de Interação Fluido Estrutura (IFE) que utiliza o conceito de fronteiras imersas como alternativa a abordagens ALE (Arbitrary Lagrangian Eulerian) clássicas. Elementos Finitos Generalizados, juntamente com Multiplicadores de Lagrange, são utilizados para prover descontinuidade nos campos de velocidade e pressão do fluido ao longo da interface com a estrutura. O acoplamento dos dois problemas é realizado utilizando um método implícito e alternado (staggered scheme), que possui a vantagem de permitir, facilmente, a implementação de códigos computacionais desenvolvidos para resolver isoladamente o problema fluido e/ou estrutural. / This work is divided in three parts. Initially, it is presented a stabilized Finite Element Method formulation to solve fluid flow problems governed by the incompressible Navier-Stokes Equations. This formulation was implemented in a computer code and validated throughout several numeric simulations. Some well-known finite elements with different pairs of velocity/pressure approximations, as well as some other less popular elements, were investigated and their performance compared. The second part describes the Structural Problem formulation. This formulation is able to simulate nonlinear dynamic problems involving large displacements and finite strains during long period of time. In the final part of this work, it is proposed a Fluid-Structure Interaction method based on an immersed interface approach in opposition to classical ALE (Arbitrary Lagrangian Eulerian) approaches. Generalized Finite Elements, together with Lagrange Multipliers, are used to provide velocity and pressure discontinuities on the fluid domain across the immersed interface. To couple both fluid and structural problems, an implicit staggered scheme is adopted, which allows the easy implementation of already developed black box computer codes.
579

No limiar dos Impérios: projetos, circulações e experiências na fronteira entre a Capitania do Rio Negro e a Província de Maynas (c.1780-c.1820) / On the threshold of Empires: projects, circulations and experiences in the border area between the Captaincy of Rio Negro and the Province of Maynas (1780-1820)

Bastos, Carlos Augusto de Castro 24 September 2013 (has links)
Esta tese analisa as políticas destinadas à área fronteiriça entre a Capitania do Rio Negro e a Província de Maynas, bem como as circulações e experiências que caracterizaram esse espaço amazônico. O recorte cronológico abarca, inicialmente, os trabalhos de demarcação de limites empreendidos por representantes das Coroas espanhola e portuguesa, na década de 1780, compreendendo ainda os anos de crise política do Antigo Regime e a eclosão dos movimentos de independência na América nas primeiras décadas do século XIX. Nesse trabalho, privilegia-se uma análise que atente para as relações transfronteiriças, os impactos no espaço em questão das grandes transformações vivenciadas pelos impérios ibéricos e as leituras, interpretações e ações gestadas pelos sujeitos que habitavam essa fronteira ibero-americana. / This thesis examines the policies concerning the border area between the Captaincy of Rio Negro and the Province of Maynas, as well as the circulations and experiences that characterize this Amazonian space. Initially, the chronological period considered includes the demarcation of boundaries undertaken by representative members of the Spanish and Portuguese crowns in the 1780s, the years of political crisis of the Old Regime, and the outbreak of the independence movements in America in the early decades of the XIXth century. In this work, the analysis attempts to cross-border relations, the impacts this space has suffered due to great changes experienced by the Iberian empires, and also, the readings, interpretations and actions generated by the subjects who inhabited this Iberoamerican frontier.
580

A alimentação e seus impactos ambientais: abordagens dos guias alimentares nacionais e estudo da dieta dos brasileiros / Food and its environmental impacts: approaches of national dietary guidelines and a study on the diet of Brazilians

Garzillo, Josefa Maria Fellegger 13 December 2018 (has links)
As dietas monótonas, com elevado consumo de carnes e alimentos ultraprocessados pioram o quadro de segurança alimentar porque aceleram registros epidemiológicos de doenças crônicas enquanto degradam os ecossistemas. Indicadores ambientais aplicados sistematicamente no campo da alimentação revelam as evidências científicas e as justificativas éticas que suportam a integração de educação nutricional e ambiental nos guias alimentares nacionais. Um grande desafio da atualidade é fortalecer as métricas das dietas saudáveis e sustentáveis, o que inclui desenvolver indicadores ambientais atrelados à qualidade nutricional dos padrões alimentares. Primeiro, nós fizemos uma avaliação qualitativa de como os guias nacionais inseriram as questões ambientais nas suas recomendações, seguida de estudo quantitativo sobre quanto que a adoção de dietas saudáveis pelos brasileiros reduziria os impactos ambientais. Pela análise de conteúdo, usando técnicas como a triagem de expressões e a categorização temática, nós relacionamos um extenso repertório ambiental aos Limites Planetários dentro dos quais a humanidade pode viver em segurança: uso de água doce, poluição química, integridade da biosfera, mudanças no uso do solo e nos sistemas da Terra, mudanças climáticas e fluxo biogeoquímico. Guias integrados recomendaram escolher alimentos com etiqueta ecológica oriundos da produção local e orgânica, as preparações caseiras compostas principalmente por vegetais frescos e sazonais, e moderadas em carnes, evitando os alimentos ultraprocessados, as embalagens, o consumo excessivo e os desperdícios. Água e alimentos contaminados por patógenos, alimentos vegetais por pesticidas e peixes por mercúrio foram questões apresentadas mesmo por guias com escopo restrito à nutrição. As recomendações conectaram as mudanças climáticas ao consumo de carne, mas também ao uso de energia e ao transporte. Para o estudo quantitativo, nós criamos uma nova base de dados ambientais com pegadas de carbono e hídrica obtidas em publicações internacionais de avaliação de ciclo de vida para todos os itens de consumo presentes na Pesquisa de Orçamentos Familiares (2008-2009) do Instituto Brasileiro de Geografia e Estatística. As pegadas dos alimentos e das preparações culinárias consumidos pelos brasileiros estão disponíveis para uso direto como fatores de cálculos integrados à tabela de composição nutricional. Na primeira aplicação da base de dados ambientais, nós calculamos as pegadas de carbono e hídrica do consumo alimentar médio (4,1kgCO2eq e 4120 litros de água), de uma dieta saudável simulada (3,5 kgCO2eq e 3410 litros de água) e de cenários definidos por cinco estratos de participação percentual de energia na dieta provenientes dos alimentos ultraprocessados e cinco estratos das carnes em geral. Fizemos o estudo comparativo das pegadas com as dietas equalizadas em 2000kcal e 60g de proteína. Comparamos os impactos ambientais atrelados à qualidade nutricional por diferentes unidades funcionais (100g, 100kcal e grama de proteína). O maior consumo de carnes apresentou as pegadas mais altas (6,4kgCO2eq e 6293 litros de água). O maior consumo de ultraprocessados (4,2kgCO2eq e 3789 litros de água) apresentou pegadas comparáveis ao consumo médio. Se 200 milhões de brasileiros adotassem a dieta saudável, eles reduziriam as emissões em 45 milhões de toneladas de carbono ao ano. / Monotonous diets with high meat and ultra-processed foods consumption worsen the food security status because they accelerate epidemiological records of chronic diseases while degrading ecosystems. Environmental indicators systematically applied in the field of nutrition reveal scientific evidences and ethical justifications to support nutritional and environmental education integration in national dietary guidelines. A big challenge today is strengthening metrics of healthy and sustainable diets, which includes developing environmental indicators linked to nutritional quality of food patterns. First, we made a qualitative evaluation of how the national guidelines have inserted environmental issues in their recommendations, followed by a quantitative study on how much the healthy diets adoption by Brazilians would reduce environmental impacts. By content analysis, using techniques such as expressions screening and thematic categorization, we linked an extensive environmental repertoire to the Planetary Boundaries within which humanity could live safely: freshwater use, chemical pollution, biosphere integrity, land use and the Earth systems change, climate change and biogeochemical flow. Integrated guidelines recommended choosing eco-labeled food from local and organic production, home made meals mostly composed by fresh and seasonal vegetables, moderate in meat, avoiding ultra-processed foods, packaging, overconsumption and waste. Water and food contaminated by pathogens, plant foods by pesticides and fish by mercury were issues presented even by guidelines with scope restricted to nutrition. Food recommendations connected climate change to meat consumption, but also to energy use and transportation. For the quantitative study, we created a new environmental database with carbon and water footprints obtained from international life cycle assessment publications for all consumption items in the Family Budget Survey (2008-2009) of the Instituto Brasileiro de Geografia e Estatística. The footprints of foods and culinary preparations consumed by Brazilians are available to direct use as calculations factors integrated to the nutritional composition table. In the very first application of the environmental database, we calculated the carbon and water footprints of average food consumption (4.1 kgCO2eq and 4120 liters of water), a simulated healthy diet (3.5 kgCO2eq and 3410 liters of water) and scenarios defined by five quintils of dietary energy participation of ultra-processed foods and five quintils of red meats in general. We compared footprints using equalized diets in 2000 kcal and 60 g protein. We compared environmental impacts linked to nutritional quality by different functional units (100g, 100kcal and grams of protein). The highest meat consumption had the highest footprints of all (6.4kgCO2eq and 6293 liters of water). The highest consumption of ultra-processed had footprints (4.2kgCO2eq and 3789 liters of water) comparable to the average consumption. If 200 million Brazilians would adopt the healthy diet, they would reduce emissions in 45 million tons of carbon per year.

Page generated in 0.046 seconds