• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 381
  • 133
  • 28
  • 27
  • 22
  • 20
  • 17
  • 13
  • 12
  • 7
  • 4
  • 2
  • 2
  • 2
  • 1
  • Tagged with
  • 828
  • 284
  • 266
  • 98
  • 87
  • 80
  • 74
  • 73
  • 73
  • 73
  • 71
  • 66
  • 63
  • 57
  • 54
  • 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.
51

Sustainable area planning framework for ecologically sustainable development

Rauscher, Raymond January 2009 (has links)
Research Doctorate - Doctor of Philosophy (PhD) / The thesis is partly a response to the increasing numbers of people expressing concerns over a number of environmental issues (i.e. impact of climate change; greenhouse gas emissions; and, depleting natural resources). Governments, in response, are trying to develop a more sustainable approach to urban development. The thesis proposes a sustainable area planning (SAP) framework to incorporate sustainability principles (social/cultural, environmental, and economic) in urban planning within different sized areas, including: local; district; local government; and, region. The thesis examines current urban planning schools (land use planning, natural resource planning and sustainable urban planning). The research focuses on the extent that these schools incorporate principles of sustainability within urban planning frameworks. The research aims to condense and build on these frameworks to develop a more coordinated and holistic framework. The proposed SAP framework is a five (5) step process with templates developed to accompany each step. The thesis acknowledges the wide range of sustainability data sources available, and shows how these sources can be utilized within the framework. Both qualitative (i.e. SAP survey step) and quantitative (i.e. SAP sustainability scorecard step) methods are used within the framework. A case study urban growth area of North Wyong District (in the Greater Metropolitan Region of Sydney) is nominated to test the framework. As the framework is developed, questions posed on how best to measure the environment leads to the development of indicators of sustainability. Sustainability scorecards are also developed to record these indicators of sustainability. A system of sustainability ratings (using green, amber and red) is proposed. The thesis then tests aggregating (scaling up) these ratings to larger areas. The final research aim is to test whether the scorecard results can form the basis of a sustainability report (with actions and monitoring components) for a subject area. The thesis draws a conclusion that the SAP framework does work and can be used as a tool to incorporate principles of sustainability into urban planning. Finally, suggested future research directions are outlined, including: 1. adopting a systems program for the SAP framework application; 2. using the framework for environmental performance monitoring; and, 3. broadening the framework to accommodate the social and economic components of sustainability.
52

Sustainable area planning framework for ecologically sustainable development

Rauscher, Raymond January 2009 (has links)
Research Doctorate - Doctor of Philosophy (PhD) / The thesis is partly a response to the increasing numbers of people expressing concerns over a number of environmental issues (i.e. impact of climate change; greenhouse gas emissions; and, depleting natural resources). Governments, in response, are trying to develop a more sustainable approach to urban development. The thesis proposes a sustainable area planning (SAP) framework to incorporate sustainability principles (social/cultural, environmental, and economic) in urban planning within different sized areas, including: local; district; local government; and, region. The thesis examines current urban planning schools (land use planning, natural resource planning and sustainable urban planning). The research focuses on the extent that these schools incorporate principles of sustainability within urban planning frameworks. The research aims to condense and build on these frameworks to develop a more coordinated and holistic framework. The proposed SAP framework is a five (5) step process with templates developed to accompany each step. The thesis acknowledges the wide range of sustainability data sources available, and shows how these sources can be utilized within the framework. Both qualitative (i.e. SAP survey step) and quantitative (i.e. SAP sustainability scorecard step) methods are used within the framework. A case study urban growth area of North Wyong District (in the Greater Metropolitan Region of Sydney) is nominated to test the framework. As the framework is developed, questions posed on how best to measure the environment leads to the development of indicators of sustainability. Sustainability scorecards are also developed to record these indicators of sustainability. A system of sustainability ratings (using green, amber and red) is proposed. The thesis then tests aggregating (scaling up) these ratings to larger areas. The final research aim is to test whether the scorecard results can form the basis of a sustainability report (with actions and monitoring components) for a subject area. The thesis draws a conclusion that the SAP framework does work and can be used as a tool to incorporate principles of sustainability into urban planning. Finally, suggested future research directions are outlined, including: 1. adopting a systems program for the SAP framework application; 2. using the framework for environmental performance monitoring; and, 3. broadening the framework to accommodate the social and economic components of sustainability.
53

Designing Sorbent-Containing Electrospun Fibers For Dilute Chemical Separations

January 2018 (has links)
abstract: An urgent need for developing new chemical separations that address the capture of dilute impurities from fluid streams are needed. These separations include the capture of carbon dioxide from the atmosphere, impurities from drinking water, and toxins from blood streams. A challenge is presented when capturing these impurities because the energy cost for processing the bulk fluid stream to capture trace contaminants is too great using traditional thermal separations. The development of sorbents that may capture these contaminants passively has been emphasized in academic research for some time, producing many designer materials including metal-organic frameworks (MOFs) and polymeric resins. Scaffolds must be developed to effectively anchor these materials in a passing fluid stream. In this work, two design techniques are presented for anchoring these sorbents in electrospun fiber scaffolds. The first technique involves imbedding sorbent particles inside the fibers: forming particle-embedded fibers. It is demonstrated that particles will spontaneously coat themselves in the fibers at dilute loadings, but at higher loadings some get trapped on the fiber surface. A mathematical model is used to show that when these particles are embedded, the polymeric coating provided by the fibers may be designed to increase the kinetic selectivity and/or stability of the embedded sorbents. Two proof-of-concept studies are performed to validate this model including the increased selectivity of carbon dioxide over nitrogen when the MOF ZIF-8 is embedded in a poly(ethylene oxide) and Matrimid polymer blend; and that increased hydrothermal stability is realized when the water-sensitive MOF HKUST-1 is embedded in polystyrene fibers relative to pure HKUST-1 powder. The second technique involves the creation of a pore network throughout the fiber to increase accessibility of embedded sorbent particles. It is demonstrated that the removal of a blended highly soluble polymer additive from the spun particle-containing fibers leaves a pore network behind without removing the embedded sorbent. The increased accessibility of embedded sorbents is validated by embedding a known direct air capture sorbent in porous electrospun fibers, and demonstrating that they have the fastest kinetic uptake of any direct air capture sorbent reported in literature to date, along with over 90% sorbent accessibility. / Dissertation/Thesis / Doctoral Dissertation Chemical Engineering 2018
54

Evolução do método FrameWeb para o projeto de Sistemas de Informação Web utilizando uma abordagem dirigida a modelos

SOUZA, B. F. M. 18 April 2016 (has links)
Made available in DSpace on 2018-08-02T00:03:56Z (GMT). No. of bitstreams: 1 tese_9803_beatriz franco - evolucao_do_metodo_frameweb_para_o_projeto_de_sistemas_de_informacao_web_utilizando_uma_abordagem_dirigida_a_modelos_2016.pdf: 5320289 bytes, checksum: ce7c2db454cdbddae063081fb3bdf663 (MD5) Previous issue date: 2016-04-18 / Em um contexto de mercado cada vez mais competitivo, o desenvolvimento de Sistemas de Informação baseados na Web (WIS - Web Information Systems) necessita ser cada vez mais dinâmico e eficiente. A Engenharia Web (WebE - Web Engineering) ao longo dos anos vem propondo diversos métodos para análise, projeto e desenvolvimento de WIS. Em 2007 foi proposto o método de projeto WIS FrameWeb, que define uma arquitetura básica para desenvolvimento de WIS baseado em framewoks. A proposta de arquitetura do método FrameWeb teve foco em um conjunto específico de framewoks disponíveis à época, definindo alguns procedimentos e um perfil UML para criar uma infraestrutura próxima ao estado-daprática, cuja função é proporcionar ganho de produtividade, principalmente na transição entre as fases de projeto e de desenvolvimento, aproveitando as vantagens do uso de framewoks e de sua ampla utilização, bem como o amplo conhecimento de UML por parte dos modeladores e desenvolvedores. Entretanto, com o surgimento de novas técnicas, especificações e implementações de framewoks se fez necessário revisitar o método e avaliar as evoluções necessárias para sua continuidade. Além disso, a partir de sua aplicação, observou-se que de ferramentas CASE baseadas em UML deixam a cargo do modelador e de sua experiência a responsabilidade quanto às atividades a serem desempenhadas e ao uso dos construtos propostos, dando margem a falhas. Observando estas questões, este trabalho propõe a definição e formalização do método FrameWeb por meio de um metamodelo, denominado FW-15, por meio do uso de técnica Desenvolvimento Orientado a Modelos (MDD - Model-Driven Development). O metamodelo FW-15 tem a finalidade de garantir não apenas a semântica da linguagem FrameWeb no que diz respeito ao seu aspecto framework-independente, mas também permitir a evolução do método, pois define uma metodologia para a criação de Definições de Frameworks, contendo os construtos e regras necessárias para a criação e aplicação de Perfis FrameWeb responsáveis pelos aspectos framework-dependente. Assim, esta proposta pretende manter total compatibilidade com a versão original do método e ao mesmo tempo adicionar os recursos necessários para que novas técnicas e framewoks possam ser agregados formalmente ao método. Como contribuição adicional este trabalho apresenta um protótipo de ferramenta simplificada para modelagem com o método FrameWeb e determina as diretrizes para a evolução deste protótipo de forma a permitir o desenvolvimento de uma ferramenta gráfica apropriada ao método.
55

Designing and Evaluating a Development Framework

Darinder, Fredrik January 2006 (has links)
Object-Oriented frameworks, OO frameworks, have been discussed over a long period of time, that when introducing Object-Oriented frameworks, the defect-density will decrease and the quality of software will increase. Capgemini had developed a framework that had been in the organization for nine years. Since then, the framework has been reengineered several times to meet the continuously changing requirements of the software systems the framework supports. My work was to develop a new framework to make the maintainability and evolution of the framework easier while not compromising the quality of the framework or the applications built on it. The new framework that I developed was called the Capgemini Development Framework, CDF. Results from the case study, conducted to test the differences between these two frameworks, showed that the CDF framework preserved the maintainability of the applications built on the framework. The architecture of the CDF framework made it also easier to handle any future updates to the core functionality of the framework.
56

Integrating knowledge seeking into knowledge management models, frameworks, and strategies

Lottering, F.B. (Francois Barnardus) 26 June 2012 (has links)
Knowledge management (KM) is something that we as humans have practiced for generations by means of sharing stories around the fireplace, passing down recipe books, teaching trade crafts to children and showing young adults how to hunt. This primitive version of KM was not described as an area of development or expertise within organisations until 1995 when Nonaka and Takeuchi’s SECI model revolutionised the world of KM. Since then, many KM researchers have contributed to the field and tried to establish its true foundations. As a result, many KM models and frameworks have emerged leading to a call for the standardisation of KM terminology, and the harmonisation of about 160 existing KM models and frameworks. What has been strikingly overlooked in all these KM models and frameworks is the idea of knowledge seeking as a necessary theoretical component and as a key KM process. Only recently there have been a few attempts to integrate knowledge seeking into KM models and frameworks. With a view to taking this development further, this study achieves two things. First, the study assesses the theoretical status of knowledge seeking in some of the established KM models, frameworks and strategies, and reviews the work of KM researchers who have grappled with the idea of knowledge seeking. Second, the study describes some of the key features of knowledge seeking in a sample of companies. Four companies were selected according to their type and size. They included a small business intelligence consulting company, a branch office of a country-wide IT company, a department within a larger insurance company, and a company that deals with financial software. Using questionnaires and descriptive statistical methods to generate, analyse and interpret the data, the study delineates some of the key features of knowledge seeking in the workplace by asking where people seek knowledge to solve problems, where they seek knowledge under the pressure of time, and where they would prefer to seek knowledge in ideal circumstances. On the basis of the data, the study revises Han Lai and Margaret Graham’s KM life cycle model, which is the latest version of a KM model that integrates knowledge seeking. Additionally, the study adapts Hansen et al’s codification versus personalisation KM strategy. The study therefore contributes to the theoretical aspects of KM by showing that knowledge seeking deserves sustained analysis in KM models and frameworks as a KM process, and it contributes to KM practice by showing the implications of knowledge seeking for KM strategies. Copyright / Dissertation (MIS)--University of Pretoria, 2012. / Information Science / unrestricted
57

Caracterización de la Adsorción de Hidrógeno en MOFs por Métodos Químico-Computacionales

Gómez Hernández, Diego Armando 11 October 2012 (has links)
En los últimos años, los esfuerzos para desarrollar una fuente de energía limpia y econó³micamente viable se han incrementado. Estos esfuerzos surgen como respuesta al creciente consumo de combustibles y al alto impacto ambiental y socio-político de la exploración y el uso de hidrocarburos o energía nuclear. Una de las alternativas más prometedoras exploradas hoy en díaa es el uso de H2 como vector energético. Sin embargo, existen algunas limitaciones relacionadas con la producciónn y almacenamiento que deben ser superadas. Centrados en el problema del almacenamiento de H2 , en esta investigación se ha estudiado, empleando técnicas químico-computacionales, las propiedades físico-quí�micas que promueven la adsorción de hidrógeno en sólidos cristalinos microporosos metal-orgánicos (MOFs). A partir del análisis de los resultados, se han identificado algunos parámetros que pueden ser utilizados como referencia para orientar el diseño y la síntesis de nuevos MOFs con mejores propiedades para la adsorción de H2 . A lo largo del estudio, los siguientes aspectos han sido evaluadas en detalle: I. la naturaleza de las interacciones moleculares entre el adsorbato y los diferentes componentes del material y II. las características estructurales que promueven o limitar la adsorción. Estos aspectos fueron estudiados con técnicas de químico-computacionales, tales como cálculos de química cuántica (con métodos los semi-empíricos PM6, HF y MP2) y simulaciones de dinámica molecular y Monte Carlo. Los resultados se analizaron en una función de las propiedades fÃ�sicas de los ma- teriales seleccionados para el estudio. En una primera fase, la interacción de las moléculas de H2 con el MOF-5 se evaluaron a través de cálculos de química cuántica. En vista de que los sitios de adsorciónn más fuertes fueron localizados en posiciones cercanas a los Átomos del metal (Zn (II)), se realiza un estudio adicional con cuatro tipos de centros metálicos...... / Gómez Hernández, DA. (2012). Caracterización de la Adsorción de Hidrógeno en MOFs por Métodos Químico-Computacionales [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/17462 / Palancia
58

The development of Namibia's renewable energy regime

Heita, Natalia Ndatilohamba January 2015 (has links)
As is the case with many countries, Namibia has an economy dependent on fossil fuels. The country is, however, blessed with abundant and diverse - but as yet unexploited - renewable energy (RE) resources that could be used for improving the livelihood of the vast majority of its 2.2 million people. Today the conflict between energy production from fossil fuels and protection of the environment is intensifying and this compels all countries to search for means of resolving this conflict. Developing RE through the enactment of enabling legislation and implementation of relevant policy is one important step towards attaining the ideal of an energy-secure future. This state of affairs is not unique to Namibia, as most countries with abundant RE sources are striving to promote and deploy RE in their respective regimes through appropriate policies and legal frameworks. This study examines Germany and Ghana from, respectively, the developed and developing world, as leading countries that have established a proactive RE regime. However, such a regime can only be successfully achieved if countries, including Namibia, adopt laws and policies that promote and encourage the use of RE in order to move away from fossil fuel dependence to a greener economy. Thus the study seeks to investigate RE resources in Namibia and their potential development. It outlines the current legislation pertaining to the regulation of RE in Namibia. As such, the study further examines the Organisation for Economic Cooperation and Development (OECD) guidelines and draws examples from other regimes, particularly Germany and Ghana, in order to provide a guideline for the enactment of a general Energy Act with a particular chapter on RE. It concludes with recommendations as to how Namibia can secure a sustainable energy future.
59

Novel zeotype frameworks with soft cyclodiphosphazane linkers and soft Cu₄X₄ clusters as nodes

Siddiqui, Mujahuddin M., Mobin, Shaikh M., Senkovska, Irena, Kaskel, Stefan, Balakrishna, Maravanji S. 26 November 2019 (has links)
Two novel cyclodiphosphazane cluster frameworks with Cu₄X₄ clusters as tetrahedral nodes and ferrocenyl cyclodiphosphazanes [Fe(η5-C5H₄)₂(PNtBu)₂] as ditopic linkers have been synthesized. These frameworks having sodalite topology display a unique integration of porosity and redox activity and offer new opportunities for the synthesis of zeotype frameworks with soft phosphorus-based ligands.
60

Metal-Macrocyclic Frameworks based on Aza-Macrocycles: Design Strategies and Applications

Ren, Junyu 05 1900 (has links)
The present thesis mainly proposes to explore the potential of aza-macrocycles in metal-organic frameworks (MOFs) for applications related to unprecedented open macrocycle cavities. Strategies such as direct arylation of secondary amines as well as multidentate coordination were applied to constrain the intramolecular flexibility of as-obtained macrocyclic compounds. Several desired materials, i.e. MMCF-4, MMCF-5/MMCF-5t/MMCF-5t-aa, MMCF-5, HMMCF-1, were obtained. They are proved superior to traditional materials in the field of "turn-on" lanthanide luminescence, deep desulfurization of flue gas, recovery of Platinum-group metals, etc. Powder/single-crystal X-ray diffraction (PXRD/SCXRD), synchrotron-based X-ray and extended X-ray absorption fine structure (EXAFS), density functional theory (DFT) theoretical calculations, etc., were employed for deep-understanding the mechanisms. These studies shed light on the construction of hierarchically porous materials with two levels of porosity, i.e., one from the frameworks and the other one from the aza-macrocycles. Incorporation of aza-macrocycles into the MOF architectures not only leads to fundamental significance in bridging the chemistry of MOFs with supramolecular chemistry but also elicits unique properties from the hybrid materials obtained. As a paradigm for constructing frameworks with accessible macrocyclic cavities based on "constrained" aza-macrocycle ligands, this thesis paves the way for the further development of this framework family in the future.

Page generated in 0.1019 seconds