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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.
1

Contribuição ao estudo da durabilidade de concretos com proteção superficial frente à ação de íons cloretos. / Contribution to the durability study of surface treated concrete exposed to chlorides ions action.

Medeiros, Marcelo Henrique Farias de 10 January 2008 (has links)
Atualmente, sabe-se que nenhum material estrutural é eternamente durável devido à ação dos agentes ambientais sobre seus componentes. No caso das estruturas de concreto armado, iniciou-se, a partir da década de 70, uma crescente preocupação com a sua deterioração e durabilidade. As soluções mais estudadas geralmente seguem a linha de melhorar as propriedades do concreto para o aumento da durabilidade da estrutura, que se trata, sem dúvida, de uma das possíveis soluções para o problema. Contudo, este trabalho aborda o aumento da durabilidade de outra forma, ou seja, tratando a superfície do concreto com o objetivo de impedir ou desacelerar o processo de corrosão. A forma de ação, neste caso, é a restrição da penetração de agentes agressivos, água e/ou oxigênio através da rede de poros capilares do concreto, componentes imprescindíveis para o desenvolvimento da corrosão. Este tipo de sistema de proteção consiste em uma barreira que funciona como um cobrimento de concreto de alta qualidade, fundamental para a proteção do aço embebido no concreto. Este trabalho apresenta uma metodologia de estudo da eficiência de produtos destinados à proteção superficial para estruturas de concreto armado submetidas ao ataque por cloretos. Além disso, no trabalho é apresentada uma comparação entre três categorias de produtos de proteção superficial: hidrofugantes de superfície, formadores de película e bloqueadores de poros. Outra contribuição é a comprovação da eficácia da aplicação de proteção de superfície sobre estruturas já contaminadas por cloretos. / Currently, it is known that no structural material is ever-lasting due to environment action on its components. In the 1970s, there was an increasing concern with deterioration and durability of reinforced concrete structures. The solutions studied generally aim to improve the concrete properties to increase the durability of the structure. Undoubtedly, this is one of the possible solutions for the problem. However, this work approaches the increase in the durability in another way, treating the surface of the concrete with the aim of inhibiting or decelerating the corrosion process. The action form, in this case, is to restrict the penetration of aggressive agents, water and/or oxygen (essential components for the development of corrosion process) through the pores of the concrete. This type of protection system consists of a barrier that functions as a concrete cover of high quality, important for the protection of the steel reinforcement inside the concrete. This work presents a methodology to study the efficiency of surface treatment used to protect reinforced concrete structures exposed to marine environment. Moreover, in this work, the efficacy of three groups of surface treatments were compared. These groups are: coatings and sealers (physical barrier); pore liners (water repellent) and pore blockers. Another contribution of this work is the evidence of the effectiveness of surface protection applied on structures contaminated with chlorides.
2

Contribuição ao estudo da durabilidade de concretos com proteção superficial frente à ação de íons cloretos. / Contribution to the durability study of surface treated concrete exposed to chlorides ions action.

Marcelo Henrique Farias de Medeiros 10 January 2008 (has links)
Atualmente, sabe-se que nenhum material estrutural é eternamente durável devido à ação dos agentes ambientais sobre seus componentes. No caso das estruturas de concreto armado, iniciou-se, a partir da década de 70, uma crescente preocupação com a sua deterioração e durabilidade. As soluções mais estudadas geralmente seguem a linha de melhorar as propriedades do concreto para o aumento da durabilidade da estrutura, que se trata, sem dúvida, de uma das possíveis soluções para o problema. Contudo, este trabalho aborda o aumento da durabilidade de outra forma, ou seja, tratando a superfície do concreto com o objetivo de impedir ou desacelerar o processo de corrosão. A forma de ação, neste caso, é a restrição da penetração de agentes agressivos, água e/ou oxigênio através da rede de poros capilares do concreto, componentes imprescindíveis para o desenvolvimento da corrosão. Este tipo de sistema de proteção consiste em uma barreira que funciona como um cobrimento de concreto de alta qualidade, fundamental para a proteção do aço embebido no concreto. Este trabalho apresenta uma metodologia de estudo da eficiência de produtos destinados à proteção superficial para estruturas de concreto armado submetidas ao ataque por cloretos. Além disso, no trabalho é apresentada uma comparação entre três categorias de produtos de proteção superficial: hidrofugantes de superfície, formadores de película e bloqueadores de poros. Outra contribuição é a comprovação da eficácia da aplicação de proteção de superfície sobre estruturas já contaminadas por cloretos. / Currently, it is known that no structural material is ever-lasting due to environment action on its components. In the 1970s, there was an increasing concern with deterioration and durability of reinforced concrete structures. The solutions studied generally aim to improve the concrete properties to increase the durability of the structure. Undoubtedly, this is one of the possible solutions for the problem. However, this work approaches the increase in the durability in another way, treating the surface of the concrete with the aim of inhibiting or decelerating the corrosion process. The action form, in this case, is to restrict the penetration of aggressive agents, water and/or oxygen (essential components for the development of corrosion process) through the pores of the concrete. This type of protection system consists of a barrier that functions as a concrete cover of high quality, important for the protection of the steel reinforcement inside the concrete. This work presents a methodology to study the efficiency of surface treatment used to protect reinforced concrete structures exposed to marine environment. Moreover, in this work, the efficacy of three groups of surface treatments were compared. These groups are: coatings and sealers (physical barrier); pore liners (water repellent) and pore blockers. Another contribution of this work is the evidence of the effectiveness of surface protection applied on structures contaminated with chlorides.
3

Longevidade de restaurações ART em cavidades ocluso-proximais utilizando diferentes técnicas de inserção e proteção superficial / Proximal ART restorations using different insertion techniques and surface protection materials

Daniela Hesse 05 August 2015 (has links)
O objetivo desta pesquisa foi avaliar a longevidade de restaurações ocluso-proximais realizadas pelo Tratamento Restaurador Atraumático (ART) com duas formas de inserção do cimento de ionômero de vidro (CIV - técnica convencional e técnica em duas camadas), assim como avaliar a influência do tipo de proteção superficial (vaselina sólida e resina fluida com nanopartículas - G-Coat Plus® - GC Corp). Além disso, investigou-se o desgaste clínico das restaurações convencionais de ART protegidas com vaselina sólida e G-Coat Plus®. Lesões de cárie ocluso-proximais em molares decíduos de 208 crianças foram selecionadas e divididas aleatoriamente em quatro grupos: grupo 1, inserção do CIV de maneira convencional e proteção superficial realizada com vaselina; grupo 2, inserção do CIV pela técnica em duas camadas e proteção superficial realizada com vaselina; grupo 3, inserção do CIV de maneira convencional e proteção superficial realizada com G-Coat Plus®; grupo 4, inserção do CIV pela técnica em duas camadas e proteção superficial realizada com G-Coat Plus®. As restaurações foram avaliadas clinicamente após 1, 6, 12, 18, 24 e 36 meses. Adicionalmente, 32 crianças foram selecionadas (16 pertencentes ao grupo 1 e 16 pertencentes ao grupo 3) para serem submetidas a impressões do hemi-arco envolvendo a restauração realizada com moldeira parcial e silicona de adição, para posterior obtenção de modelos com o uso de resina ortoftálica. As moldagens foram realizadas 1 dia após a realização das restaurações (baseline) e durante as avaliações de 6, 12, 18, 24 e 36 meses. Os modelos obtidos foram levados para Academic Centre for Dentistry Amsterdam (ACTA), Holanda, para análise do desgaste superficial do material restaurador em aparelho de scanner em 3D e a subtração das imagens obtidas foi realizada em programa de computador apropriado. Foram realizados análise de sobrevida de Kaplan-Meier e teste de Log-rank para avaliar a taxa de sobrevida das restaurações. A análise de regressão de Cox foi usada para verificar a influência de fatores clínicos na longevidade das restaurações. Para avaliação do desgaste das restaurações foi aplicado o teste ANOVA de dois fatores e Tukey post-hoc. O nível de significância para os testes foi considerado como 5%. Os resultados demonstraram que a sobrevida global das restaurações foi de 52,8% após 36 meses de acompanhamento e o tipo mais comum de falha encontrado foi a fratura/perda da restauração, sendo este tipo de falha significativamente mais prevalente no grupo de restauração de ART convencional protegido com vaselina (p<0,05). A análise de sobrevida indicou uma melhor sobrevida das restaurações realizadas pela técnica em duas camadas, em comparação com restaurações convencionais (p=0,005), enquanto as restaurações convencionais protegidas com GCoat Plus® apresentaram maior sobrevida, em comparação com aquelas protegidas com vaselina (p=0,035). A análise de regressão de Cox não mostrou nenhuma influência de qualquer variável testada na longevidade das restaurações. Em relação ao desgaste clínico, observou-se uma menor taxa de desgaste das restaurações protegidas com o GCoat Plus® quando a área selecionada de 1mm2 foi analisada (p<0,05). Porém quando todo o hemi-arco do paciente foi considerado, não houve diferença significativa entre os dois grupos avaliados (p>0,05). Pode-se concluir que a sobrevida de restaurações ocluso-proximais realizadas pelo ART em dentes decíduos é maior quando realizadas com a técnica em duas camadas. Além disso, a proteção superficial do CIV realizada com a resina fluida nanoparticulada aumenta a longevidade e reduz o desgaste das restaurações convencionais de ART em dentes decíduos. / The aim of this research was to evaluate the survival rate of occluso-proximal restorations performed by the Atraumatic Restorative Treatment (ART) with two different insertion techniques of the glass ionomer cement (GIC - conventional technique and bilayer technique), and assess the influence of the type of surface protection (petroleum jelly and a nanofilled particles coating for GIC - G-Coat Plus® - GC Corp). Furthermore, we investigated the clinical wear of conventional ART-restorations protected with petroleum jelly and G-Coat Plus®. Occluso-proximal caries lesion in primary molars from 208 schoolchildren were selected and randomly assigned into four groups: group 1, conventional GIC insertion protected with petroleum jelly; G2, bi-layer technique protected with petroleum jelly; G3 conventional GIC insertion protected with G-Coat Plus®; G4, bi-layer technique protected with G-Coat Plus®. The restorations were clinically evaluated after 1, 6, 12, 18, 24 and 36 months. Additionally, 32 children were selected (16 from group 1 and 16 from group 3) to have impressions of the hemi-arc involving the restoration accomplished. The impressions were carried out 1 day after treatment and during the assessment periods of 6, 12, 18, 24 and 36 months. The impressions were taken to the Academic Centre for Dentistry Amsterdam (ACTA), The Netherlands, to have the restorative material wear evaluated in 3D scanner and the obtained images were subtracted in appropriate computer software. Kaplan-Meier survival analysis and log-rank tests were performed to verify the survival rate of restorations. Cox regression analysis was used to verify the influence of clinical factors in the longevity of restorations. Two-way ANOVA and Tukey post-hoc test were used to analyze the wear of the restorations. The significance level for the tests was considered as 5% .The results showed that the overall survival rate of the restorations was 52.8% after 36 months of follow-up and the most prevalent type of failure was fracture / loss of restoration, in that conventional ART-restoration protected with petroleum jelly group presented significantly more prevalence of this type of failure (p<0.05). Survival analysis showed better survival of the two layers technique compared with conventional insertion of GIC (p=0.005), while the conventional restorations protected with G-Coat Plus® showed higher survival rate compared with those protected with petroleum jelly (p=0.035). Cox regression analysis showed no influence of any variable tested on the longevity of restorations. Regarding the clinical wear, there was a significant difference between the coated and uncoated restorations when the selected area of 1mm2 of the restoration was investigated (p<0.05), with a clear wear protection offered by the application of nanofilled resin coat; however when investigating the hemi-arch of patients, there were no significant differences between the two materials (p>0.05). We can conclude that the survival rate of the approximal ART-restorations in primary teeth was positively influenced by the bi-layer technique. Furthermore, the application of a nanofilled particles coating for GIC increased the longevity and decreased the wear of conventional ART-restorations in primary teeth when compared to petroleum jelly.
4

Longevidade de restaurações ART em cavidades ocluso-proximais utilizando diferentes técnicas de inserção e proteção superficial / Proximal ART restorations using different insertion techniques and surface protection materials

Hesse, Daniela 05 August 2015 (has links)
O objetivo desta pesquisa foi avaliar a longevidade de restaurações ocluso-proximais realizadas pelo Tratamento Restaurador Atraumático (ART) com duas formas de inserção do cimento de ionômero de vidro (CIV - técnica convencional e técnica em duas camadas), assim como avaliar a influência do tipo de proteção superficial (vaselina sólida e resina fluida com nanopartículas - G-Coat Plus® - GC Corp). Além disso, investigou-se o desgaste clínico das restaurações convencionais de ART protegidas com vaselina sólida e G-Coat Plus®. Lesões de cárie ocluso-proximais em molares decíduos de 208 crianças foram selecionadas e divididas aleatoriamente em quatro grupos: grupo 1, inserção do CIV de maneira convencional e proteção superficial realizada com vaselina; grupo 2, inserção do CIV pela técnica em duas camadas e proteção superficial realizada com vaselina; grupo 3, inserção do CIV de maneira convencional e proteção superficial realizada com G-Coat Plus®; grupo 4, inserção do CIV pela técnica em duas camadas e proteção superficial realizada com G-Coat Plus®. As restaurações foram avaliadas clinicamente após 1, 6, 12, 18, 24 e 36 meses. Adicionalmente, 32 crianças foram selecionadas (16 pertencentes ao grupo 1 e 16 pertencentes ao grupo 3) para serem submetidas a impressões do hemi-arco envolvendo a restauração realizada com moldeira parcial e silicona de adição, para posterior obtenção de modelos com o uso de resina ortoftálica. As moldagens foram realizadas 1 dia após a realização das restaurações (baseline) e durante as avaliações de 6, 12, 18, 24 e 36 meses. Os modelos obtidos foram levados para Academic Centre for Dentistry Amsterdam (ACTA), Holanda, para análise do desgaste superficial do material restaurador em aparelho de scanner em 3D e a subtração das imagens obtidas foi realizada em programa de computador apropriado. Foram realizados análise de sobrevida de Kaplan-Meier e teste de Log-rank para avaliar a taxa de sobrevida das restaurações. A análise de regressão de Cox foi usada para verificar a influência de fatores clínicos na longevidade das restaurações. Para avaliação do desgaste das restaurações foi aplicado o teste ANOVA de dois fatores e Tukey post-hoc. O nível de significância para os testes foi considerado como 5%. Os resultados demonstraram que a sobrevida global das restaurações foi de 52,8% após 36 meses de acompanhamento e o tipo mais comum de falha encontrado foi a fratura/perda da restauração, sendo este tipo de falha significativamente mais prevalente no grupo de restauração de ART convencional protegido com vaselina (p<0,05). A análise de sobrevida indicou uma melhor sobrevida das restaurações realizadas pela técnica em duas camadas, em comparação com restaurações convencionais (p=0,005), enquanto as restaurações convencionais protegidas com GCoat Plus® apresentaram maior sobrevida, em comparação com aquelas protegidas com vaselina (p=0,035). A análise de regressão de Cox não mostrou nenhuma influência de qualquer variável testada na longevidade das restaurações. Em relação ao desgaste clínico, observou-se uma menor taxa de desgaste das restaurações protegidas com o GCoat Plus® quando a área selecionada de 1mm2 foi analisada (p<0,05). Porém quando todo o hemi-arco do paciente foi considerado, não houve diferença significativa entre os dois grupos avaliados (p>0,05). Pode-se concluir que a sobrevida de restaurações ocluso-proximais realizadas pelo ART em dentes decíduos é maior quando realizadas com a técnica em duas camadas. Além disso, a proteção superficial do CIV realizada com a resina fluida nanoparticulada aumenta a longevidade e reduz o desgaste das restaurações convencionais de ART em dentes decíduos. / The aim of this research was to evaluate the survival rate of occluso-proximal restorations performed by the Atraumatic Restorative Treatment (ART) with two different insertion techniques of the glass ionomer cement (GIC - conventional technique and bilayer technique), and assess the influence of the type of surface protection (petroleum jelly and a nanofilled particles coating for GIC - G-Coat Plus® - GC Corp). Furthermore, we investigated the clinical wear of conventional ART-restorations protected with petroleum jelly and G-Coat Plus®. Occluso-proximal caries lesion in primary molars from 208 schoolchildren were selected and randomly assigned into four groups: group 1, conventional GIC insertion protected with petroleum jelly; G2, bi-layer technique protected with petroleum jelly; G3 conventional GIC insertion protected with G-Coat Plus®; G4, bi-layer technique protected with G-Coat Plus®. The restorations were clinically evaluated after 1, 6, 12, 18, 24 and 36 months. Additionally, 32 children were selected (16 from group 1 and 16 from group 3) to have impressions of the hemi-arc involving the restoration accomplished. The impressions were carried out 1 day after treatment and during the assessment periods of 6, 12, 18, 24 and 36 months. The impressions were taken to the Academic Centre for Dentistry Amsterdam (ACTA), The Netherlands, to have the restorative material wear evaluated in 3D scanner and the obtained images were subtracted in appropriate computer software. Kaplan-Meier survival analysis and log-rank tests were performed to verify the survival rate of restorations. Cox regression analysis was used to verify the influence of clinical factors in the longevity of restorations. Two-way ANOVA and Tukey post-hoc test were used to analyze the wear of the restorations. The significance level for the tests was considered as 5% .The results showed that the overall survival rate of the restorations was 52.8% after 36 months of follow-up and the most prevalent type of failure was fracture / loss of restoration, in that conventional ART-restoration protected with petroleum jelly group presented significantly more prevalence of this type of failure (p<0.05). Survival analysis showed better survival of the two layers technique compared with conventional insertion of GIC (p=0.005), while the conventional restorations protected with G-Coat Plus® showed higher survival rate compared with those protected with petroleum jelly (p=0.035). Cox regression analysis showed no influence of any variable tested on the longevity of restorations. Regarding the clinical wear, there was a significant difference between the coated and uncoated restorations when the selected area of 1mm2 of the restoration was investigated (p<0.05), with a clear wear protection offered by the application of nanofilled resin coat; however when investigating the hemi-arch of patients, there were no significant differences between the two materials (p>0.05). We can conclude that the survival rate of the approximal ART-restorations in primary teeth was positively influenced by the bi-layer technique. Furthermore, the application of a nanofilled particles coating for GIC increased the longevity and decreased the wear of conventional ART-restorations in primary teeth when compared to petroleum jelly.
5

Valoriser les connaissances issues des expériences vécues pour recommander des actions de protection des sources d'eau potable : application du raisonnement à base de cas

Cerutti, Jérôme 20 February 2023 (has links)
Depuis des décennies, les pays du monde entier s'affairent à préserver leurs précieuses ressources en eau potable. Ils cherchent à anticiper les risques et à réduire les impacts anthropiques qui pourraient altérer les sources d'approvisionnement. Au Canada, la protection des sources d'eau potable (PSEP) est mise en œuvre au sein de l'approche à barrières multiples, dont elle est l'une des barrières fondamentales. Cette approche permet une gestion multidimensionnelle de l'eau à l'aide d'outils et des pratiques visant à assurer la qualité de l'eau de la source au robinet. Bien que différents cadres existent pour prendre en compte l'eau dans l'aménagement du territoire, la mise en œuvre de la protection des sources peine à se concrétiser. Pourtant, les acteurs de l'eau et de l'aménagement du territoire ont une grande expérience dans la mise en œuvre d'actions. Alors, comment partager ces expériences afin de les soutenir dans l'identification et la mise en œuvre de futures actions de protection des sources ? Le but de cette thèse est de développer un prototype de système d'aide à la décision à base de connaissances (KB-DSS). Celui-ci a pour objectif de faciliter l'identification d'actions ciblées de PSEP selon les problèmes rencontrés. Pour ce faire, ce prototype a été développé sur la base des connaissances issues des expériences vécues depuis deux décennies au Québec, mettant à contribution des expériences réelles de mise en œuvre d'actions liées à la protection de l'eau. Il est conçu pour être utilisable par tout acteur ayant un intérêt à agir pour protéger les sources d'eau potable à l'échelle locale et régionale, via un transfert de connaissances dans le processus d'élaboration et de mise en œuvre d'actions. En étant un support dans la définition des actions futures, le prototype développé entend encourager les parties prenantes à apprendre les unes des autres. L'originalité de la thèse repose sur l'adoption combinée de l'approche en science du design/de la conception (DSR), qui a servi de lignes directrices pour adopter une démarche collaborative et transparente. Celle-ci a permis une application réussie du raisonnement à base de cas (CBR) au complexe problème de la PSEP dans un cadre de gestion de l'eau et du territoire. De cette démarche sont nés différents outils méthodologiques, procédures et connaissances permettant de mieux comprendre les problèmes liés à la PSEP, mais également d'illustrer la conception intégrale d'un prototype d'aide à la décision à base de connaissances utilisant le CBR. Tout d'abord, le cadre conceptuel (chapitre 1) explore et tente de comprendre les liens qui existent entre la nature des problèmes à résoudre pour protéger l'eau, l'environnement décisionnel et la prise de décision. Pour ce faire, le cadre adopte une approche systémique et holistique superposant différentes théories et concepts tels que la gouvernance de l'eau, la gestion de l'eau, la prise de décision, la rationalité et la connaissance. Cette compréhension des défis sous-jacents à la mise en œuvre de la PSEP permettait de mieux comprendre la complexité du problème à résoudre et posait les bases à l'élaboration du prototype de système CBR proposé. Dans l'optique de mieux comprendre comment les défis soulevés dans le cadre conceptuel se concrétisent en pratique, le second chapitre présente une enquête en ligne documentant la mise en œuvre de la PSEP au Québec. Celle-ci visait à brosser un portrait-diagnostic permettant de mieux comprendre le processus décisionnel, d'identifier qui sont les intervenants et quelles sont les connaissances produites et mobilisées pour la prise de décision sur la PSEP. Les analyses qualitatives et quantitatives des réponses des 208 intervenants retenus ont permis de constater que la mise en œuvre de la PSEP impliquait une grande diversité d'intervenants, de tâches et de connaissances créées et se caractérisait par un fort dynamisme inter-organisationnel. Cependant, on constatait que son processus décisionnel perdait en inclusivité au fil des étapes de mise en œuvre, que les connaissances étaient parfois redondantes et qu'il existait de nombreux enjeux de transfert de connaissances (accès, quantité ou qualité des connaissances) entre les intervenants. Lors de l'enquête en ligne présentée au second chapitre, il a été demandé à certains acteurs (organismes de bassins versants, villes, municipalités régionales de comté) d'illustrer les problèmes liés à la PSEP rencontrés sur le terrain. En parallèle, 102 intervenants se sont auto-recrutés pour participer au processus de design du système d'aide à la décision. Le troisième chapitre présente la démarche d'acquisition et de structuration des connaissances du dit KB-DSS par une approche CBR. Le chapitre décrit une seconde enquête en ligne ayant permis de définir ce qu'est un cas pour la PSEP, soit une expérience vécue qui consiste en une multitude de problèmes et de solutions mises en œuvre. Puis, il décrit la modélisation d'une taxonomie des connaissances ayant permis d'aboutir à des descriptions structurées des cas. La conception des cas repose sur le savoir-faire et les besoins en connaissances exprimés par les acteurs de l'eau. La base de cas constitue l'épine dorsale du prototype de KB-DSS destiné à guider les décideurs dans l'élaboration de solutions fondées sur des expériences passées. Le quatrième chapitre présente le prototype de KB-DSS/CBR pour la protection des sources d'eau potable. Il retrace comment le CBR a été modélisé, structuré, implanté, testé et validé en collaboration avec les 102 acteurs de la gestion et de la gouvernance de l'eau au Québec. Il décrit l'intégralité du processus manuel d'ingénierie de cas pour concevoir des attributs qualitatifs sur la base de la taxonomie des connaissances. Il présente l'édition des cas, le processus et les métriques permettant de retrouver des cas, l'implantation et un exemple d'utilisation ainsi que la validation du prototype, réalisée par une procédure participative rigoureuse et transparente avec un petit groupe d'acteurs de l'eau du Québec. Ainsi, il fournit des preuves empiriques du potentiel positif d'une approche CBR pour la PSEP sur le territoire, et retrace une démarche qui peut être généralisée à d'autres contextes géographiques et socio-économiques similaires. / Countries worldwide have been working for decades to preserve their precious drinking water resources. They seek to anticipate risks or reduce anthropogenic impacts that could alter the water quality and availability. In Canada, drinking water source protection (DSWP), or source water protection (SWP), is implemented as part of the multi-barrier approach and is one of the fundamental barriers. This approach allows for multidimensional water management using tools and practices to ensure water quality from source to tap. Although various frameworks exist to consider water in spatial planning, the implementation of DWSP is struggling to materialize. However, water and spatial planning actors have significant experience implementing actions. So, how can these experiences be shared to support them in identifying and implementing future DWSP actions? The goal of this thesis is to develop a prototype of a knowledge-based decision support system (KB-DSS). The objective of this prototype is to facilitate the identification of targeted actions for water protection according to the problems encountered. To do so, this prototype was developed based on knowledge gained from past experiences conducted over the last two decades in Quebec, using real experiences in implementing actions related to water protection. It is designed to be used by any actor with an interest in contributing for the protection of drinking water sources at the local and regional levels, through the transfer of knowledge in the process of developing and implementing actions. By being a support in the definition of future actions, the developed prototype intends to encourage the actors to learn from each other. The originality of the thesis lies in the combined adoption of the design science approach (DSR), which served as a guideline to adopt a collaborative and transparent approach. This allowed for a successful application of case-based reasoning (CBR) to the complex problem of DWSP in a water and territory management framework. From this approach, various methodological tools, procedures and knowledge were developed to better understand the DWSP problems, but also to illustrate the complete design of a prototype knowledge-based decision support system using CBR. First, the conceptual framework (chapter 1) explores and attempts to understand the links between the nature of the problems to be solved to protect water, the decision-making environment, and the decision-making process. These issues were explored by adopting a system analysis that allowed for layering concepts such as water governance, water management, decision-making, rationality, and knowledge. This holistic understanding of the underlying challenges of DWSP implementation provided a better understanding of the complexity of the problem at hand and laid the foundation for developing the proposed CBR system. To better understand how the challenges raised in the conceptual framework materialize in practice, the second chapter presents an online survey documenting the implementation of DWSP in Quebec. This survey aimed to provide a diagnostic portrait to understand the decision-making process better and identify the actors and the knowledge produced and mobilized for DWSP decision-making. Qualitative and quantitative analyses of the responses from the 208 selected actors revealed that the implementation of DWSP involved a wide variety of actors, tasks and knowledge created and was characterized by great inter-organizational dynamism. However, it was found that the decision-making process becomes less inclusive as actions are implemented. Also, the knowledge was sometimes redundant, and there were many problems with the knowledge transfer (access, quantity, or knowledge quality) between actors. During the online survey presented in the second chapter, selected actors (watershed organizations, municipalities, counties, etc.) were asked to illustrate DWSP-related problems encountered in the field. In parallel, 102 actors were self-recruited to participate in the design process of the KB-DSS. The third chapter presents the acquisition and structuring of DWSP problem-related knowledge. The chapter describes a second online survey that helped define a DWSP case, i.e., a lived experience consisting of a multitude of problems and solutions implemented at various scales by various actors. It then describes the modelling of a knowledge taxonomy that led to structured case descriptions. The design of the cases is based on the expertise and knowledge needs expressed by the water actors. The case base is the backbone of the KB-DSS prototype to guide decision-makers in developing solutions based on past experiences. The fourth chapter presents the prototype KB-DSS/CBR system for DWSP. It traces how CBR was modelled, structured, implemented, tested and validated in collaboration with 102 water management and governance actors in Quebec. It describes the entire manual case engineering process for the design of qualitative attributes from the knowledge taxonomy. It presents the case base, the case edition, and the case retrieval (process and metrics). This chapter also illustrates the implementation using a real-world experience use case, as well as the validation of the prototype, carried out through a transparent, participatory procedure with a small group of water actors in Quebec. Thus, it provides empirical evidence of the high potential of a CBR approach for DWSP in the spatial planning context and describes an approach that can be generalized to other similar geographical and socio-economic contexts.
6

Utilização de quitosana no controle sobre a formação de hot spots e protetor superficial de nanoesferas de ouro para estudos de adsorção por espalhamento Raman intensificado por superfície

Oliveira, Débora Guimarães de 31 August 2018 (has links)
Submitted by Geandra Rodrigues (geandrar@gmail.com) on 2018-11-05T13:41:09Z No. of bitstreams: 1 deboraguimaraesdeoliveira.pdf: 3971933 bytes, checksum: 7b5a0ee6a3a033ca0149c8adc512aea2 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2018-11-23T11:16:07Z (GMT) No. of bitstreams: 1 deboraguimaraesdeoliveira.pdf: 3971933 bytes, checksum: 7b5a0ee6a3a033ca0149c8adc512aea2 (MD5) / Made available in DSpace on 2018-11-23T11:16:07Z (GMT). No. of bitstreams: 1 deboraguimaraesdeoliveira.pdf: 3971933 bytes, checksum: 7b5a0ee6a3a033ca0149c8adc512aea2 (MD5) Previous issue date: 2018-08-31 / A proteção superficial de nanoesferas de ouro (AuNEs) pode fornecer uma maior estabilidade coloidal, importante quando se trabalha com sistemas biológicos, por apresentarem situações diversas que podem levar à agregação das AuNEs. O biopolímero quitosana (Quit) é um material atóxico, apresenta baixo custo, e vem sendo muito utilizado em sistemas biológicos para diagnóstico de doenças. Sistemas sensíveis, como os biossensores utilizados na detecção de moléculas adsorvidas em AuNEs, podem ser monitorados por mudança na banda de ressonância de plasmon de superfície localizado (LSPR) e pela utilização da técnica de espalhamento Raman intensificado por superfície (SERS). Quando as moléculas são adsorvidas nas superfícies das AuNEs é possível observar a indução de agregação da suspensão coloidal pela mudança na banda LSPR. Devido à sensibilidade analítica, as superfícies das AuNEs são protegidas para evitar agregação e precipitação coloidal, e a obtenção de resultados falso-positivos. Esta tese teve como objetivo realizar vários estudos utilizando as AuNEs protegidas superficialmente por Quit para oferecer uma maior estabilidade e controlar a formação de hot spots na presença do analito. Para tal, sempre foram realizados experimentos comparando as AuNEs com e sem proteção superficial por Quit. Os estudos iniciais observaram a resistência à agregação das AuNEs com relação ao tempo de exposição em temperatura ambiente. Seguindo o raciocínio as AuNEs também foram expostas à diferentes concentrações dos agentes agregantes etanol (EtOH) e KCl. Os analitos utilizados como molécula prova para o SERS e também para observar possíveis mudanças na banda LSPR, foram os corantes: cristal violeta (CV), rodamina 6G (R6G) e IR-820, que apresentam cargas superficiais positiva ou negativa; a fim de identificar alguma preferência na adsorção por carga superficial do analito. Para os estudos em espectroscopia SERS, foram realizadas medidas variando concentração de Quit na presença dos corantes juntos ou separados, além de observar a interferência na ordem de adição do corante no sinal SERS. A Quit se mostrou promissora para aumentar a estabilidade das AuNEs e, portanto, experimentos para tentar modular e controlar a formação de hot spots foram realizados. O efeito SERS foi utilizado como uma ferramenta analítica em que foi estudada a relação direta do sinal SERS obtido dos corantes, com a sua concentração em solução. A partir destes resultados, foi possível construir isotermas de adsorção dos corantes estudados, que foram ajustadas ao modelo de Langmuir. / The surface protection of gold nanospheres (AuNEs) can provide greater colloidal stability, important when work with biological system, because the present diverse situations that can lead to the aggregation of AuNEs. The chitosan biopolymer (Quit) is a non-toxic material, presents low cost, and has been widely in biological systems for the diagnosis of diseases. Sensitive systems, such as biosensors used in detection of adsorbed molecules in AuNEs, can be monitored by changing in Localized Surface Plasmon Resonance´s band (LSPR) and by use of Surface-Enhanced Raman Spectroscopy technique (SERS). When the molecules are adsorbed on the AuNEs surfaces is possible to observe the induction of aggregation of the colloidal suspension by the change in the LSPR band. Due to the analytical sensitivity, the surfaces of the AuNES are protected to avoid aggregation and colloidal precipitation, and to obtain false positive results. This thesis aimed to perform several studies using the AuNEs surface protected by Quit to offer greater stability and to control the formation of hot spots in the presence of the analyte. For this, experiments were always done to compare the AuNEs with and without surface protection by Quit. The initial studies observed the resistance to AuNEs aggregation in relation to exposure time at room temperature. Following the reasoning, the AuNEs were also exposed to different concentrations of the aggregating agents ethanol (EtOH) and KCl. The analytes that were used as a test molecule for the SERS and also to observe possible changes in the LSPR band were the dyes: crystal violet (CV), rhodamine 6G (R6G) and IR-820, which have positive or negative surface charges; in order to identify some preference in surface adsorption of the analyte. For the SERS spectroscopy studies, measurements were performed varying the concentration of Quit in the presence of the dyes together or separated, besides observing the interference in the order of dye addition in the SERS signal. The Quit proved promising to increase the stability of AuNEs and, therefore, modification experiments, aiming at modulate and control the formation of hot spots, were performed. The SERS effect was used as an analytical tool in which the direct relationship of the SERS signal obtained from the dyes with their concentration in solution was studied. From these results, it was possible to construct adsorption isotherms of the studied dyes, which were adjusted to the Langmuir model.
7

Les enjeux politiques de la gouvernance environnementale : le cas de la gestion des eaux de surface à São Paulo

Dumas, Rose-Marie 11 June 2018 (has links)
Dans un contexte où les changements climatiques se manifestent sous forme de phénomènes climatiques extrêmes tels que des sècheresses prolongées et des précipitations abondantes soudaines, la question de la texture des sols urbains et de la protection des sources d’eau fait l’objet de nouvelles préoccupations en matière de planification urbaine. Alors que la régulation et la filtration de l’eau de ruissèlement sont restreintes par l’imperméabilité des surfaces urbaines, plusieurs métropoles, dont São Paulo, peuvent se retrouver en situation de crises dues à l’indisponibilité de l’eau potable, aux inondations subites ou à la création d’îlots de chaleur. L’efficacité de la gouvernance environnementale appliquée à la gestion des eaux en milieu métropolitain devient donc primordiale. Par une étude de cas de la métropole de São Paulo, la présente recherche tente d’élucider les facteurs rendant possible l’atteinte d’un modèle de gouvernance environnementale métropolitain qui permettrait de maintenir les fonctions écosystémiques des bassins versants et de construire la résilience à la variabilité climatique. La stratégie d’enquête, basée sur l’analyse de documents scientifiques et gouvernementaux, l’observation participante et la tenue d’entretiens semi-dirigés, permit de soulever plusieurs obstacles à l'application des politiques publiques de protection des espaces verts et des sources d’eau. La carence de maîtrise de l’usage des sols, la priorisation des intérêts économiques, la sectorisation des instances gouvernementales et la faible intégration de la société civile au processus de prise de décision surgissent comme d’importants freins à la construction d’une gouvernance environnementale à São Paulo. La considération des savoirs scientifiques et locaux et la gestion du risque lié à la variabilité climatique sont marginalisées par la sphère politique. Ainsi, la présence d’une vaste législation environnementale, telle qu’en vigueur dans la métropole de São Paulo, ne signifie pas forcément une application des projets et des règlements sans faille. / In a context where climate changes are manifested by extreme climatic events such as prolonged droughts and sudden abundant rainfall, the issue of urban soil texture and water protection is a new concern in urban planning. While the regulation and filtration of runoff water is restricted by the impermeability of urban surfaces, several cities, including São Paulo, may end up in crisis due to the unavailability of drinking water, floods or creation of heat islands. The effectiveness of environmental governance applied to water management in metropolitan areas therefore becomes paramount importance. Through a case study of the metropolis of São Paulo, this research attempts to elucidate the factors that make it possible to achieve a metropolitan environmental governance that would maintain watersheds ecosystem functions and build resilience to climate variability. The research strategy, based on the analysis of scientific and governmental documents, participant observation and semistructured interviews, shows several obstacles to the application of public policies for the protection of green spaces and water sources. The lack of control over land use, the prioritization of economic interests, the governmental sectoralization and the weak integration of civil society into the decision-making process appear as major obstacles to the construction of environmental governance in São Paulo. Scientific and local knowledges and climate risk management are marginalized by the political sphere. Thus, the presence of a vast environmental legislation, as in place in the metropolis of São Paulo, does not necessarily mean an unfailing application of projects and regulations.

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