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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.
191

UBIQUOS - arcabouço multiplataforma para jogos colaborativos utilizando interface distribuída de usuário. / UBIQUOS - multi-platform framework for collaborative games with distributed interface.

Pedro Matsumura Kayatt 25 October 2016 (has links)
O aumento no número de dispositivos móveis de alto desempenho e a disponibilidade de conexões sem fio permitiram o desenvolvimento de interfaces que são compartilhadas entre diversos dispositivos; tais interfaces são chamadas de Interfaces Distribuídas de Usuários. Esta pesquisa foca no desenvolvimento de um arcabouço que visa simplificar o desenvolvimento de jogos digitais que utilizem interfaces distribuídas, assim como analisar o atual estado da arte de outras tecnologias e arcabouços. É proposto um estudo de aceitação, utilizando parâmetros quantitativos e qualitativos, afim de comprovar as características necessárias para uma experiência fluída para o usuário. Tal tarefa é analisada através da criação de um jogo protótipo onde diversos jogadores podem jogar juntos e compartilhar informações entre diversos dispositivos. / The increasing number of high-end mobile devices and increased connection availability have allowed on the development of interfaces that can be shared between multiple devices; such interfaces are called Distributed User Interfaces. This research aims the development of a framework to simplify the development of games using distributed interfaces, as well as to assay the current state-of-art of technologies and frameworks. We propose a study of the acceptance, using both qualitative and quantitative parameters, in order to verify compliance with the necessary characteristics for a fluid user experience. This is accomplished through the creation of a prototype game in which several players can play together and share information through many devices.
192

MOFs à surface modulable pour l’encapsulation et la libération de macromolécules / Engineered Surface Metal Organic Frameworks (MOFs) for Encapsulation and Delivery of Macromolecules

Hidalgo Crespo, Tania 02 December 2015 (has links)
L'émergence d’un nouveau système nanoparticulé dans le domaine biomédical, les matériaux hybride poreux du type MOF (pour Metal Organic Framework), a récemment attiré beaucoup d'attention en raison de leur grande versatilité structurale et chimique. En particulaire, le trimésate de fer(III) mésoporeux (MIL-100; MIL pour Matériau de l'Institut Lavoisier) a démontré des capacités remarquables de stockage de médicaments avec leur libération contrôlée dans des conditions physiologiques, ainsi que des propriétés en imagerie très intéressantes.Néanmoins, avant toute bioapplication, il estnécessaire d’étudier leur toxicité et leur profile de biodistribution, lesquels sont fortement affectés par plusieurs facteurs (composition, dégradabilité, chimie de surface, etc.). Ainsi, l’objectif principal de ce travail de thèse porte sur l'évaluation de la biocompatibilité de MOFs nanométriques et leur passage de barrières physiologiquespar différentes voiesd'administration (en particulier, par voie intraveineuse, orale et cutanée) en fonction de leurs propriétés physico-chimiques. / The recent emergence of nanometric porous metal-organic frameworks (nanoMOFs) in the biomedical field has recently attracted a great deal of attention owing to their large porosity and versatile composition. Particularly attractive is the mesoporous iron(III) trimesate (MIL-100; MIL stands for Material of Institute Lavoisier), which has shown exceptional loading of challenging drugs, together with their controlled release under physiological conditions and interesting imaging properties. Nevertheless, prior to any bioapplication, it is crucial investigate its toxicity and biodistribution profile, which are strongly affected by multiple factors (e.g. composition, degradability, surface engineering, etc.). Thus, the aim of this PhD work focuses on the evaluation of the nanoMOF biocompatibility and their physiological barrier crossing from different administration routes (specifically intravenous, oral and cutaneous) as a function of their physicochemical properties.
193

NMR spectroscopy in adsorption studies of metal-organic frameworks

Sin, Maria 19 January 2019 (has links)
The present thesis deals with the investigation of liquid-phase and gas-phase adsorption of metal-organic frameworks (MOFs) using NMR spectroscopy. NMR-based methods are developed and then applied to characterize the surface polarity of studied materials and the influence of structural flexibility on the adsorption selectivity. In the first part of the thesis a new methodology for surface polarity screening of MOFs is proposed based on quantitative 1H NMR spectroscopic measurements of liquid-phase adsorption. The influence of the surface polarity on the adsorption process was studied on several materials, e.g. activated carbons, PAF-1, MIL-101(Cr), HKUST-1, and UiO-67-series. The surface polarity was characterized through the difference in the 1,4-dioxane adsorption uptake from two solvents of opposite polarity, namely n-heptane and N,N-dimethylformamide. An NMR-derived surface polarity index was defined where the polarity of the MOF corresponds to its affinity to polar substances. It was demonstrated that the structural modifications of MOF materials, which should affect the polarity of these MOFs, are indeed reflected by the proposed polarity index. The second part of the thesis focuses on gas mixture adsorption experiments. Metal-organic frameworks are promising candidates for selective separation processes such as CO2 from methane. Framework flexibility is observed only for some special MOFs. The main question is: Does framework flexibility influence the adsorption selectivity? High-pressure in situ 13C NMR spectroscopy was used to monitor the adsorption of 13CO2/13CH4 gas mixtures. This method allows to distinguish between the two gases as well as between adsorbed molecules and the interparticle gas phase. Gas mixture adsorption was performed under isothermal conditions. The selectivity factor for CO2 adsorption from CO2/CH4 mixtures was measured as a function of total gas pressure. The flexible material SNU-9 as well as the flexible and the non-flexible forms of DUT-8(Ni) were compared. Maximum selectivity factors for CO2 were observed for the flexible form of DUT-8(Ni) in its open-pore state. In contrast, the rigid form of DUT-8(Ni) and SNU-9 especially in its intermediate state exhibit lower adsorption selectivity factors. This observation indicates significant influence of the framework flexibility on the adsorption selectivity.
194

[en] IMINE-BASED COFS SYNTHESIS AIMING CO2 CAPTURE AND CONVERSION / [pt] SÍNTESE DE COFS BASEADOS EM IMINAS VISANDO A CAPTURA E CONVERSÃO DE CO2

MARCELO FOLHADELLA MARTINS FARIA AZEVEDO 11 January 2022 (has links)
[pt] No contexto da redução da concentração de CO2 na atmosfera e utilizar o mesmo na síntese de produtos de interesse, buscou-se sintetizar COFs com propriedades biomiméticas da enzima anidrase carbônica capaz de converter CO2. O chamado Tppa-NO2-COF foi planejado a partir dos blocos de construção triformilfluoroglucinol e 2-nitro 1,4-fenilenodiamina (comercialmente disponível). O triformilfluoroglucinol foi previamente sintetizado pela reação de Duff, entretanto outras metodologias alternativas foram testadas de forma a melhorar as condições reacionais e o custo atrelado ao processo. Em decorrência da não reprodutibilidade das metodologias sintéticas do Tppa-NO2-COF reportadas na literatura, foi necessário um processo de otimização (variando tipo e quantidade de solvente, concentração do ácido, condição reacional, entre outros). A influência do grupamento nitro no Tppa-NO2 foi igualmente avaliada, através da síntese do material análogo sem o nitro, o chamado Tppa-1-COF, o qual foi obtido com área de 434 m2/g, condizente com o dado reportado na literatura. Outra metodologia abordada para a síntese desses materiais foi a sonificação (sonochemistry) que demonstrou ser uma excelente alternativa para a síntese dos materiais de maneira eficaz e rápida. Entretanto, o material foi obtido com cristalinidade e área específica baixas e muito variáveis (de 40 a 628 m2/g), o que, por definição não pode ser chamado de COF, sendo então tratado como Covalent Organic Network (CON). Apesar da adversidade, seguiu-se com as modificações pós-sintéticas no Tppa-NO2-CON, realizando a redução do grupamento nitro e consequente reação do grupo amina para formar linkers que permitissem a atividade biomimética à enzima via ligação peptídica ou via triazol, capazes de se coordenar ao íon zinco. Otimizações ainda se fazem necessárias para a obtenção do COF, bem como estudos mais aprofundados nas modificações pós sintéticas e de adsorção de CO2, aplicação na conversão de CO2 a bicarbonato e outros produtos de interesse para a síntese orgânica. / [en] In the context of reducing the concentration of CO2 in the atmosphere and using it in the synthesis of products of interest, we sought to synthesize COFs with biomimetic properties of the carbonic anhydrase enzyme capable of converting CO2. The so-called Tppa-NO2-COF was designed from the building blocks triformylfluoroglucinol and 2-nitro 1,4-phenylenediamine (commercially available). Triformylfluoroglucinol was previously synthesized by the Duff reaction, however other alternative methodologies were tested in order to improve the reaction conditions and the cost linked to the process. Due to the non-reproducibility of synthetic methodologies of Tppa-NO2-COF reported in the literature, an optimization process (varying type and amount of solvent, acid concentration, reaction condition, among others) was necessary. The influence of the nitro group on Tppa-NO2 was also evaluated, through the synthesis of an analogous material without nitro, the so-called Tppa-1-COF, which was published with an area of 434 m2/g, consistent with what is reported in the literature. Another approach to synthetic materials for sonification (sonochemistry) includes being an excellent alternative for an efficient and rapid synthesis of materials. However, the material was found with low and highly variable crystallinity and specific area (from 40 to 628 m2/g), which, by definition, cannot be called COF, being treated as Covalent Organic Network (CON). Despite the adversity, post-synthetic modifications in the Tppa-NO2-CON followed, performing the reduction of the nitro group and consequent reaction of the amine group to form ligands that would allow a biomimetic activity to the enzyme via peptide bond or via triazole, from coordinate with the zinc ion. Optimizations are still necessary to obtain the COF, as well as in-depth studies on post-synthetic modifications and CO2 adsorption, application in the conversion of CO2 to bicarbonate and other products of interest to organic synthetic.
195

Synthesis, Structure, Magnetic, Luminescent and Photocatalytic Studies on Metal-Organic Framework (MOF) Compounds

Mahata, Partha January 2009 (has links) (PDF)
The research in the area of metal-organic frameworks (MOFs) continues to be interesting for their unique structures and tunable properties. In this thesis, the various aspects of metal-organic frameworks (MOFs) compounds are presented. As part of this study, preparation of MOFs of transition metals (Mn, Co, Ni, Zn), rare-earth metals (Y, La, Pr, Nd, Gd, Dy) and mixed metals (3d-4f) using aromatic carboxylates as linker ligands were accomplished. Structures of the synthesized compounds have been determined by single crystal X-ray diffraction technique. Magnetic properties of the transition metal based compounds have been studied by SQUID magnetometer and the magnetic behaviors have been correlated with their structures using suitable theoretical model. Photocatalytic properties on transition metal and mixed metal compounds have been investigated. Ligand-sensitized metal-center emission has been studied on the Eu3+ and Tb3+ doped MOF compounds of La and Y. Up-conversion luminescence properties of Nd based compounds have also been studied. To gain an insight into the possible mechanism of the formation of MOF compounds, a detailed study of the role of temperature and time during the synthesis has been undertaken. In addition, the transformations of low-dimensional structures to structures of higher dimensionality was also studied, both in the solid state as well as in the solution mediated processes. In Chapter 1 of the thesis an overview of framework compounds is presented. In Chapter 2, the synthesis, structure and magnetic properties of benzene tricaboxylate and 4,4’-oxybis(benzoate) compounds of 3d metals are presented. Some of these compounds show unusual structure and interesting magnetic properties. For example, three-dimensional MOF with -Mn-O-Mn- Kagome layer exhibits canted antiferromagntic behavior. Three-dimensional MOF based on body centered arrangement of Co4 clusters shows two-dimensional ferromagnetic behavior. In Chapter 3, the role of temperature and time of reaction in the formation of MOF compounds and the transformation studies are presented. These studies give a clue regarding the mechanism for the synthesis of MOF compound. In chapter 4, synthesis, structure and luminescent properties of rare-earth and 3d-4f mixed metal compounds are presented. The thermal decomposition of Gd-Co-pyridine carboxylate indicates the formation of nano-sized perovskite oxide at temperature ~ 700 °C. In chapter 5, the photocatalytic behavior for the decomposition of organic dyes using MOF compounds are presented.
196

Modularização com orientação a aspectos de frameworks desenvolvidos com linguagens de padrões de análise

Oliveira, André Luiz de 17 September 2010 (has links)
Made available in DSpace on 2016-06-02T19:05:46Z (GMT). No. of bitstreams: 1 3276.pdf: 2803726 bytes, checksum: df932fa4f96049ba4e039732b3b37e42 (MD5) Previous issue date: 2010-09-17 / Universidade Federal de Minas Gerais / GRN (Gestão de Recursos de Negócio Business Resource Management) pattern language provides a set of patterns in analysis level to support the development of applications which deal with rental, purchase, sale and maintenance transactions of a good or service. GRENJ-OO is an object-oriented (OO) application framework built to support the instantiation of Java applications in the GRN domain. GRENJ-OO instantiates applications that include in their architecture all framework variabilities. The units of this framework, which implement each GRN pattern and their variants, are highly coupled between them, because there are concern tangling and concern scattering related to each one of those patterns. So, the aspect-orientation (OA) techniques were used in each pattern to minimize those problems and a new framework version was obtained, called GRENJ-OA. The improvements of separation of concerns, the coupling reduction, the cohesion increasing and the reduction of the number of lines of code of the majority of the patterns implemented in GRENJ-OA was the result reached after performing a quantitative evaluation based on separation of concerns, coupling, cohesion and size metrics. From the approach used to modularize this framework is introduced the Framework Product Line concept, that consists in a product line which their products are frameworks instead of software applications. From the GRENJ-OO modularization was also possible to extract a process that can be applied to modularize frameworks. This process aims to transform a framework in a Framework Product Line. / A linguagem de padrões GRN (Gestão de Recursos de Negócio) fornece um conjunto de padrões em nível de análise que apóiam o desenvolvimento de aplicações que tratam de transações de aluguel, compra, venda e manutenção de um bem ou serviço. GRENJ-OO é um framework de aplicação orientado a objetos (OO) construído para apoiar a instanciação de aplicações no domínio da GRN na linguagem Java. O framework GRENJ-OO instancia aplicações que incluem em sua arquitetura todas as variabilidades do framework. As unidades desse framework, que implementam cada padrão da GRN e suas variantes, estão altamente acopladas entre si, em virtude da existência de entrelaçamento e espalhamento de interesses relacionados a cada um desses padrões. Assim, a orientação a aspectos (OA) foi utilizada em cada um dos padrões a fim de minimizar esses problemas e uma nova versão do framework foi obtida, denominada GRENJ-OA. A melhoria dos níveis de separação de interesses, a redução do acoplamento, o aumento da coesão e redução do número de linhas de código da maioria dos padrões implementados no GRENJ-OA foram os resultados obtidos após a realização de uma avaliação quantitativa com base em métricas de separação de interesses, acoplamento, coesão e tamanho. A partir da abordagem utilizada na modularização desse framework, é introduzido o conceito de Linha de Produtos de Frameworks, que consiste em uma linha de produtos na qual seus produtos são frameworks, ao invés de aplicações de software. Com a modularização do GRENJ-OO também foi possível extrair um processo, que pode ser aplicado na modularização de frameworks. Esse processo tem o objetivo de transformar um framework em uma Linha de Produtos de Frameworks.
197

Evaluation des Metal-Organic Frameworks en adsorption et séparation des hydrocarbures

Peralta, David 02 February 2011 (has links) (PDF)
L'objectif de cette thèse était d'évaluer quelques Metal-Organic Frameworks (MOFs), choisis en fonction de leur taille de pores, de leur volume poreux et de leur stabilité thermique, en adsorption et séparation des hydrocarbures. Pour étudier le comportement général des MOFs nous avons choisi des MOFs avec des centres métalliques insaturés, des MOFs à charpente anionique et des ZIFs neutres et avons étudié leur sélectivité en séparation de trois familles d'hydrocarbures, à savoir alcanes, alcènes, aromatiques. Les MOFs à centre métallique insaturé se comportent généralement comme des zéolithes polaires, les ZIFs comme des zéolithes apolaires et/ou comme des tamis moléculaires. Les adsorbants les plus prometteurs sont testés sur des séparations d'intérêt industriel telles que la séparation des isomères de xylène, la séparation des paraffines linéaires, monobranchées et di-branchées et l'adsorption sélective du thiophène en vu de l'évaluation de ces adsorbants en désulfuration des essences.
198

Disorder and defects in functional molecular frameworks

Cliffe, Matthew James January 2015 (has links)
This Thesis explores the role of structural defects and disorder and their relationship to experimental data, with a particular emphasis on molecular framework materials. The question of how we can build atomistic models of amorphous materials from experimental data without needing to make system-specific assumptions is addressed. The role of 'structural invariance', <i>i.e.</i> the limited range of distinct local atomic environments within a material, as a restraint within reverse Monte Carlo refinement (RMC) is investigated. The operation of these invariance restraints operate is shown to be system-dependent and the challenges associated with effective refinement, <i>e.g.</i> configurational 'jamming', are also investigated. A generalisation to the 'structural simplicity', <i>i.e.</i> the simplest model, holding all else constant, is most likely to be correct. Three new metrics of structural simplicity are proposed: two intrinsically three-dimensional measures of local geometric invariance and one measure of local symmetry. These metrics are shown to robustly quantify the configurational quality. The ability of these metrics to act as effective restraints for the RMC refinement of amorphous materials is demonstrated by the construction of the first data-driven tetrahedral models of amorphous silicon. The role of defects and disorder within metal–organic frameworks (MOFs) is investigated through the canonical MOF UiO-66(Hf). Through a combination of techniques, including X-ray diffuse scattering, anomalous diffraction, total scattering and electron diffraction measurements, the existence of correlated metal-cluster absences in UiO-66(Hf) is demonstrated. Furthermore the ability to synthetically tune both the interactions and concentration of defects is shown. The thermomechanical properties of defective UiO-66(Hf) are also examined. UiO-66(Hf) is shown to rapidly densify by up to 5% (ΔV/V ) on ligand elimination. The resultant densified phase exhibits colossal (≥100MK<sup>-1</sup>) volumetric negative thermal expansion (NTE); the largest reported value for any MOF. Finally, the capability to tune the physical properties of MOFs through defect incorporation is demonstrated through the defect-dependence of both the densification and the NTE.
199

Etude de l'adsorption de composés organiques sur des matériaux poreux de type Metal Organic Framework (MOF)

Boulhout, Mohammed 12 December 2012 (has links)
Afin de répondre aux demandes des industriels de nouveaux matériaux poreux sont testés pour de nouvelles applications ou pour améliorer les procédés existants. Les adsorbants de types Metal Organic Frameworks(MOFs) ont des structures construites à partir d'unités inorganiques reliées entre elles par des ligands organiques. La possibilité de varier ces deux entités, offre une grande diversité de structures avec des cavités de tailles contrôlées. L'objectif de cette thèse a été d'évaluer les performances des MOFs pour l'adsorption de composés organiques et de comprendre les mécanismes d'adsorption. Les deux problématiques sélectionnées sont d'intérêt pour l'industrie pétrochimique. La séparation du para-xylène des autres isomères du xylène et de l'éthylbenzene, permets de répondre à la demande de matière première pour la synthèse du polytéréphtalate d'éthylène. L'adsorption des composés azotés et soufrés (teneur fixée par des législations), permets la purification de carburants. Notre étude thermodynamique est basée sur la réalisation d'isothermes d'adsorption et la détermination d'enthalpies d'adsorption par microcalorimétrie en phase liquide. L'adsorption des vapeurs des xylènes purs a été étudiée pour comprendre l'effet du solvant. Une grande variété de comportement a été observée selon les structures des MOFs. Nous avons par exemple mis en évidence l'effet de l'empilement moléculaire des isomères du xylène sur la sélectivité des MOFs. Nous avons démontré que la flexibilité des MOFs intervient sur les interactions au cours de l'adsorption des xylènes. Nous avons mis en évidence une sélectivité des MOFs possédant un centre métallique insaturé en faveur des composés azotés / In order to meet the industrials requirements, new porous materials are tested for new applications or to improve existing processes. The Metal Organic Frameworks (MOFs) are hybrids crystalline compounds made up of clusters (or chains) of metal ions coordinated by organic linkers to form three dimensional structures. The ability to vary these two entities offers to MOFs a wide variety of organized structure with pore sizes controlled. The aim of this thesis was to evaluate the MOF performances for the adsorption of organic compounds and also understand the related adsorption mechanism. The two selected issues are of interest for the petrochemical industry. The para-xylène separation from the other xylene isomers (ortho, meta) and ethylbenzene, allows to meet the demand for raw materials in the polyethylene terephthalate (PET) synthesis. The nitrogen and sulphur compounds adsorption allows the purification of fuels (sulphur content set by legislation). We present a thermodynamic study of adsorption from solution based on the determination of adsorption isotherms by depletion method and adsorption enthalpies by microcalorimetry. The pure xylenes vapour adsorption was also studied to understand the solvent effect. A wide variety of behaviour has been observed depending on MOF structures. For example we demonstrated the effect of xylene isomers molecular packing on MOF selectivity. Furthermore we have shown that the MOF structure flexibility influence the interactions involved during xylene isomers adsorption. We also demonstrated that MOF with unsaturated metallic centres present selectivity for nitrogen compounds (Lewis acid/base).
200

[en] CONTEXT-AWARE APPLICATION DEVELOPMENT USING MULTI-AGENT SYSTEMS / [pt] DESENVOLVIMENTO DE APLICAÇÕES SENSÍVEIS AO CONTEXTO USANDO SISTEMAS MULTI-AGENTES

REGIANE LIMA DE SOUSA 06 May 2008 (has links)
[pt] O desenvolvimento de aplicações sensíveis ao contexto (ASCs) constitui-se como uma tarefa não-trivial em conseqüência das características relacionadas à sensibilidade ao contexto, como abertura, comunicação assíncrona e falta de mecanismos modulares na propagação de informações de contexto. Por outro lado, um paradigma de desenvolvimento de software é considerado uma ferramenta básica para a construção de sistemas de software. Particularmente, a Engenharia de Software para Sistemas Multi-Agentes (ESSMA) tem se apresentado como paradigma promissor para o desenvolvimento de aplicações distribuídas, abertas e extensíveis. Agentes de software são elementos cuja execução leva ao alcance dos objetivos de um sistema através de suas propriedades de interação, adaptação e autonomia. Partindo destas características, é possível propor soluções para o desenvolvimento de ASCs que facilitem a satisfação dos requisitos mencionados acima. Este trabalho tem dois objetivos principais: (1) apresentar estudos de caso envolvendo o uso de ESSMA no desenvolvimento de ASCs e (2) propor um framework como ferramenta de reuso de sensibilidade ao contexto nas aplicações. A avaliação dos estudos e da proposta do framework é utilizada para a demonstração da usabilidade de ESSMA em ASCs. A avaliação dos estudos é efetuada através da generalização de resultados, além da aplicação de métricas com foco em atributos, como a modularidade. / [en] The development of context-aware applications (CAAs) is not a trivial task due to their intrinsic features, such as openness, asynchrony communication, and the lack of modular abstractions and mechanisms for the propagation of context information. On the other hand, a software development paradigm is actually considered a basic tool for the construction of any software system. In particular, the Software Engineering for Multi-Agent Systems (SEMAS) is often introduced as a promising paradigm for the development of distributed, open, and extensible applications. Software agents are elements whose execution leads to the reach of the system`s goals, through their interaction, adaptation, and autonomy properties. From the agent properties, it becomes possible to provide solutions for the development of CAAs in order to facilitate the satisfaction of the common requirements mentioned above. This work has two main purposes: (1) the development of case studies involving the use of SEMAS for three CAA-specific applications; (2) propose a framework to support the reuse of context- awareness features in the CAAs. The evaluation of the case studies and of the framework is used for the demonstration of SEMAS usability in the CAA-specific domain. Some evidences about the generality of the results are also provided, beyond the quantitative measurements based on common quality attributes, such as the modularity.

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