<p>The need for effective multi-level governance arrangements is becoming increasingly apparent because of the high functional interdependencies between biophysical and socioeconomic factors in the realm of natural resource governance. Such arrangements provide a basis for the exchange, discussion, and deliberation of information, knowledge, and data across diverse user groups and entities. Multi-level governance is operationalized by using a microinstitutional analysis that links decision-making arenas across three distinct levels: operational, collective-choice, and constitutional. Within this context, I argue that the effectiveness and success of actors' participatory processes across these three levels depend on the amount of social capital among actors within the governance system. I assessed the concept of social capital using two different models: (1) a structural approach focused on resources embedded within an individual's network, and (2) a combined structural-cultural approach that incorporates various aspects of group membership with relations of trust, rules, and norms. To explore the effects of social capital on participatory processes related to the implementation and management of natural resources, I analyzed different small-scale fisheries governance regimes from the Gulf of California, Mexico. I collected data using surveys (n=371), interviews (n=82), and participant observation techniques conducted among the residents of four small-scale fishing communities that live adjacent to marine protected areas along the Baja California, Mexico, peninsula. Data analysis included both quantitative (logit regression model), and qualitative (narrative analysis) approaches. Overall, my results suggest that both social capital models reveal the multidimensional nature of social capital where none of its individual types form a consistent and statistically significant relationship with the six outcomes that I measured. However, these types are related in different ways to fishers engagement in participatory processess across the three levels. The extent of fishers' engagement in participatory processess across different levels was not high. Qualitative analysis revealed that participatory processes related to fisheries conservation and management, although present do not reach their full potential and are stymied by a historical context and a lack of general participatory culture.</p> / Dissertation

The economic modernization of the Amazon fostered by the Brazilian military government during the 1960s and 1970s was largely realized without taking into consideration the presence of local households which lived from the extraction of forest products (mainly non-timber). When they began to be expulsed, a political resistance, often guided by the Catholic Church, appeared as well as the creation of unions based on traditional identities, especially that of rubber tappers. During the 1980s, these unions made a strategic alliance with the ecologist movement which started to consider traditional populations, whose lifestyle depended on the forest, as allies for the protection of the Amazon rainforest. The movement gained a decisive momentum at the end of the decade by putting forward new proposals of land tenure for traditional populations, grounded on collective land rights. This strategy has been very efficient during the 1990s and 2000s, during which about 1,300,000 km(2) of rainforest were set apart and reserved for the use of "traditional communities" under a variety of legal status. But it has also led to mix under the same "collective" etiquette and principles a number of different ways of using and managing land and natural resources. This assumption however should be nuanced by a careful analysis of the resource management systems existing in each case, for they are in general complex and mix varying proportions of individual and collective decisions. The aim of this paper is to explore this question using the example of the Chico Mendes agroextractive settlement (PAE-CM), inhabited by about 100 rubber tapper families and symbolic of the political struggle of traditional populations in the Amazon for being the home of the rubber tapper leader Chico Mendes assassinated in 1988. Applying Ostrom "design principles", we try to catch what are the local institutional arrangements and to see if they suggest collective or individual management, and what the boundaries between both categories are. As a conclusion, we find that the PAE-CM's system is much less collective than expected, and also very much controlled by external authorities, in a logic pretty much away from the idea of a CPR system. This finding is useful to understand the shortcomings in the actual management of the PAE but also to foresee difficulties which will probably arise in the management of many of the areas which have gained collective land rights or collective management statutes in the Amazon.

One seemingly lost aspect of working-class life in antebellum New Orleans stems from the effort of entrepreneurs to provide bathing and swimming facilities for the city's working poor. In exchange for a relatively inexpensive fee per use, working-class New Orleanians served as the customer base for “floating pools” moored along the Mississippi riverfront. Beginning in 1836, these pools represented a transitional phase between the long extant tradition of bathing and swimming for free in the river and the development of commercialized, waterfront pleasure resorts for the masses in the late 1800s. Close proximity of working class neighborhoods to the river allowed New Orleans entrepreneurs to capitalize on restrictions city official began to place on bathing in the river. The floating pools represented an early stage in the commercialization of recreation as well as public hygiene.

Orientador: Elaine Maria Cardoso / Resumo: O avanço de novas tecnologias, associado à minimização dos custos de fabricação e instala-ção, constitui um grande desafio para a área de refrigeração, uma vez que a geração de calor tem aumentado gradativamente nos últimos anos. Assim, a busca de novos fluidos com pro-priedades térmicas superiores aos comumente usados tornou-se indispensável para melhorar a eficiência energética. Nas últimas décadas os nanofluidos - dispersões de partículas de escala nanométrica (1 a 100nm) em um fluido-base - têm atraído especial interesse não somente da comunidade acadêmica, mas também da indústria em áreas como: a microeletrônica, microflu-ídica, transporte, manufatura, assistência médica, entre outras. O melhor desempenho térmico e a vasta gama de aplicações fazem dos nanofluidos potenciais substitutos dos refrigerantes utilizados em diversos segmentos da engenharia. Dentro desse contexto, o presente trabalho teve como objetivos: o estudo teórico e experimental da influência das propriedades termofísi-cas e concentração de nanofluidos, bem como, das características geométricas da superfície aquecedora sobre o ângulo de contato e a molhabilidade. Também, atenção foi dada à prepa-ração e caracterização dos nanofluidos (Al2O3-água e Fe2O3-água), por meio da análise expe-rimental da condutividade térmica e da viscosidade dinâmica para diferentes concentrações; uma bancada experimental, para aquisição de imagens de gota séssil, foi construída a fim de viabilizar as análises de ângulo de conta... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The advance of new technologies, associated to the minimization of manufacturing and installation costs, presents a great challenge for the refrigeration area, since the heat generation has increased in recent years. Thus, the search for new fluids with thermal properties higher than those commonly used has become indispensable to improve energy efficiency. In recent decades, nanofluids-dispersions of nanometer-scale particles (1 to 100 nm) in a base fluid - have attracted special interest not only from the academic community but also from industry in areas such as microelectronics, microfluidics, transport, manufacturing, medical assistance, among others. In this context, the present work had the following goals: the theoretical and experimental study of the influence of thermophysical properties and nanofluid concentration, as well as the geometric characteristics of the heating surface on the contact angle and wetta-bility. Attention was also given to the preparation and characterization of nanofluids (Al2O3-water and Fe2O3-water) by the experimental analysis of thermal conductivity and dynamic viscosity for different concentrations; an experimental apparatus for the acquisition of sessile droplet images was designed in order to analyze the contact angle and wettability; and a computational routine was developed to obtain the drop profile and the surface-fluid interaction for the different nanofluids and surfaces used. Based on database, it was possible to evaluate the pre... (Complete abstract click electronic access below) / Doutor

O presente trabalho envolve a análise experimental do efeito da deposição de nanopartículas por meio da ebulição em piscina na molhabilidade e na textura da superfície. Inicialmente, este estudo apresenta uma análise da literatura sobre métodos de avaliação do ângulo de contato, preparo de nanofluidos, procedimentos de avaliação da rugosidade e possíveis efeitos que a deposição de nanopartículas tem sobre a textura da superfície. Verificou-se para as superfícies recobertas com nanopartículas ângulos de contato próximos a zero e comportamento dinâmico para gotas de água depositadas sobre elas. Desta forma, optou-se por avaliar a molhabilidade qualitativamente através da análise da velocidade de espalhamento de uma gota depositada sobre a superfície recoberta. Caracterizou-se também a massa de nanopartículas depositadas, a morfologia e a rugosidade das superfícies. Efetuou-se o recobrimento das superfícies por meio da ebulição em piscina de nanofluidos a base de água deionizada contendo nanopartículas de Al2O3 (10, 20-30 e 40-80 nm), Cu (25 nm) e SiO2 (15 e 80 nm) para concentrações volumétricas de 0,001, 0,01, 0,1 e 0,5%, submetidos a tempos de ebulição de 15, 30, 45 e 180 minutos em superfícies de alumínio e aço inoxidável. Como resultado final deste estudo concluiu-se que a rugosidade superficial e a molhabilidade se elevam com a deposição das nanopartículas. Além disso, a molhabilidade aumenta com o incremento da área da superfície recoberta com aglomerados. / The present study concerns an investigation on the wettability and the surface texture behavior of flat aluminum and stainless steel plates covered with porous thin-films of nanoparticles obtained through pool boiling of nanofluids. Since the contact angle of the obtained surfaces is small and in many cases the deposited droplet exhibits a dynamic behavior, dynamic top-down analyses of spreading droplets were performed. Evaluations were performed of nanoparticles mass deposition on the sample, surface roughness and micro-structural with an SEM (Scanning Electron Microscopy). Experiments were performed for nanofluids containing nanoparticles of Al2O3 (10, 20-30 and 40-80 nm), Cu (25nm) and SiO2 (15 and 80 nm) for volumetric concentrations of 0.001, 0.01, 0.1 and 0.5% for pool boiling time set to 15, 30, 45 and 180 minutes over aluminum and stainless steel plates. As a final result of this study it was found that surface roughness and wettability increase with the deposition of the nanoparticles. In addition, the wettability increases with increasing of the surface area covered with clusters.

O estudo consistiu em uma análise teórica experimental, com o desenvolvimento de uma correlação, dos parâmetros que afetam a ebulição nucleada de refrigerantes halogenados em superfícies cilíndricas lisas. Uma ampla análise da literatura permitiu levantar os distintos tópicos envolvendo este tema destacando entre eles o presente estudo. A análise da literatura envolveu, ainda, um estudo detalhado dos fundamentos da ebulição e das correlações para a previsão do coeficiente de transferência de calor. Foi projetado e construído um aparato experimental no qual foram realizados ensaios envolvendo superfícies de aço inoxidável, cobre e latão, os refrigerantes R-11, R-123, R-12, R-22 e R-134a, fluxos específicos de calor entre 0,8 e 120 kW/m&sup2, pressões reduzidas de 0,008 a 0,26 e rugosidade aritmética média variando entre 0,02 e 3,3 &#956m. A análise destes resultados possibilitou a verificação de comportamentos físicos inéditos segundo a literatura consultada. Destaca-se a análise de efeitos da condução longitudinal e da resistência térmica de contato entre a superfície de transferência de calor e os termopares. Esta análise foi incorporada ao procedimento de determinação da temperatura superficial, e permitiu estabelecer a distribuição de temperaturas ao longo do perímetro da superfície. Finalmente, com base no banco de dados levantado, foi desenvolvida uma correlação para o coeficiente de transferência de calor em ebulição nucleada plenamente desenvolvida de refrigerantes halogenados. / The present research has been focused in a theoretical and experimental analysis of the parameters that affect the pool boiling of halocarbon refrigerants in smooth cylindrical surfaces with the development of a correlation. A wide survey of the literature allowed to list the distinct topics related to this subject and to highlight among them the theme of this study. The literature analysis still involved a detailed study of the pool boiling fundamentals and of the correlations for the pool boiling heat transfer coefficient. An experimental set up has been developed and constructed in which were raise data involving surfaces of stainless steel, copper and brass, the refrigerants R-11, R-123, R-12, R-22 and R-134a, specific heat flux range of 0.8 to 120 kW/m&sup2, reduced pressures from 0.008 to 0.26 and arithmetic mean roughness varying between 0.02 and 3.3 &#956m. The analysis of these results revealed, according to the consulted literature, unpublished physical behaviors. In this work the effects of the longitudinal conduction and of the thermal contact resistance between the heat transfer surface and the thermocouple were analyzed carefully. This analysis was incorporated to the superficial temperature determination procedure and allowed to establish the temperature distribution along the surface perimeter. Finally, using the data base raised in this research, a simple and accurate correlation for the fully developed pool boiling heat transfer coefficient for halocarbon refrigerants applications has been developed.

No cenário da pesca artesanal nacional, a garantia de acesso aos territórios pesqueiros e a construção de cadeias produtivas que valorizem ao mesmo tempo o pescado e o pescador são condições que podem ser atingidas através da organização cooperativa da produção e das comunidades. O presente trabalho se pautou nas abordagens teórico-metodológicas da ação coletiva e da gestão compartilhada dos recursos de uso comum para analisar a trajetória de duas cooperativas em comunidades tradicionais pesqueiras no Brasil: a Cooperativa dos Pescadores Artesanais de Carutapera, no litoral das reentrâncias no Maranhão, e a Cooperativa dos Produtores de Ostra de Cananéia, no litoral sul de São Paulo. Foram realizados os seguintes procedimentos metodológicos: revisão bibliográfica, levantamento de dados secundários, observação direta dos fatos e fenômenos, contato com atores chave para fornecer dados e análise contextual dos estudos de caso. Os territórios onde se encontram cada uma das cooperativas foram descritos de acordo com os aspectos demográficos, sociais, econômicos e ambientais, servindo como ponto de partida para a compreensão do estado atual das áreas de estudo. As trajetórias das ações coletivas que levaram à criação das cooperativas foram sistematizadas em uma perspectiva histórica, separadas por fases e elencados os principais acontecimentos que contribuíram para o desenvolvimento do cooperativismo local. A análise desses dados permitiu inferir quais foram as dinâmicas chave na promoção da ação conjunta e coordenada entre os indivíduos. As cadeias produtivas locais foram descritas e as relações sociais de produção que regem os aspectos de mercado nessas cooperativas foram identificadas, assim como as bases de conhecimento tradicionais e ecológicos em que ocorre a produção nos sistemas pesqueiros. Por fim, descreveram-se as áreas de uso comum utilizadas pela pesca e maricultura artesanal e o funcionamento dos regimes de propriedade empregados na gestão desses territórios. A realização dessa pesquisa possibilitou a contraposição entre os dados de ambos estudos de casos em uma perspectiva de identificação de padrões semelhantes e divergentes entre as cooperativas estudadas. As principais contribuições foram no sentido de que é preciso atentar-se ao contexto que impulsiona o empreendimento das ações coletivas que almejam melhores condições de vida para as comunidades, buscando identificar as lideranças em potencial, os motivos que fazem com que as pessoas cooperem entre si e os mecanismos que mantêm a confiança entre os indivíduos, que por sua vez leva à retroalimentação desse ciclo solidário tecido nos atributos socioecológicos e em valores como a reciprocidade. / In the context of the Brazilian artisanal fishery, the assurance of access to fishing territories and the development of value chains that consider both fish and fisherman are conditions that can be achieved through cooperative organization of production and communities. This work is based on the theoretical-methodological approaches of the collective actions and the shared management of common-use resources, especially marine resources. That background was used to analyze the historical trajectory of two cooperatives in traditional fishing communities in Brazil: the Cooperative of Artisanal Fishermen of Carutapera, in the indentation of the coastline in Maranhão State, and the Cooperative of Oyster Producers of Cananeia, in the South coastline of São Paulo State. The following methodological proceedings were carried: literature review, secondary data collection, direct observation of facts and phenomena, contact with stakeholders for the provision of data and analysis of the study cases context. The territories where each cooperative are located were described according to demographical, social, economical and environmental aspects, as a starter for the understanding of the current state of the study areas. The trajectory of the collective action that had led to the creation of the cooperatives were organized in a historical perspective, separated by phases, and it was listed/organized according by the main events that had contributed to the development of local cooperatives. The analysis of the data allowed the inference of what were the facts and key phenomena in promoting of the joint and coordinated action among individuals. The local value chain was described, and the social relations of production that deal with the market aspects in these cooperatives, were also identified as well as the traditional and ecological knowledge in what had occurred the production in the fishery systems. Finally, it was described the common areas used for fishing and artisanal mariculture, and how the property regimes employed works in the management of these territories. The realization of this research allowed the opposition between the data from both case studies in an identification prospect of similar and divergent patterns between the studied cooperatives. The main contributions were to the effect that it is necessary to pay attention to the context that drives the development of collective actions. When aimed to better living conditions for the communities, it needs to identify potential leaders, the reasons that make people cooperate with each other and the mechanisms that maintain trust between individuals, which in turn leads to feedback that solidarity cycle fabric on values such as reciprocity.

No final do século XX, observa-se uma tendência mundial de desestatização dos serviços públicos prestados diretamente pelo Estado, que se mostrava ineficiente em atender adequadamente às necessidades básicas dos cidadãos. Seguindo essa tendência, o setor elétrico brasileiro que acumulava dívidas bilionárias passou por uma completa reformulação a partir dos anos 90, consistente em um amplo processo de desestatização, com a desverticalização das atividades de geração, distribuição, transmissão e comercialização e a criação de mecanismos regulatórios de eficiência e competição. Com a criação do segmento de comercialização, os serviços de energia elétrica que eram prestados sob o regime público passaram a ser prestados também pela iniciativa privada, por meio de contratos de compra e venda de energia elétrica. Em que pese parte da doutrina clássica administrativista negar o regime privado aplicável aos serviços de energia elétrica, o presente estudo demonstra o caráter privado dos contratos de compra e venda de energia elétrica celebrados no Ambiente Livre de Contratação. Após convalidar a tese de constitucionalidade da comercialização de energia elétrica sob o prisma do direito privado, conclui-se que a energia elétrica tem natureza jurídica de bem móvel e pode perfeitamente ser objeto de contratos privados de compra e venda, com forte regulação estatal, considerando o interesse coletivo subjacente a esse bem considerado essencial. Sob a ótica do direito privado, analisamos os elementos essenciais que compõem o contrato de compra e venda e sua adequação à comercialização da energia elétrica para, ao final, corroborar a tese de que a energia elétrica é objeto de contratos privados e como tal devem ser respeitados e resistir às investidas dos Poderes legislativo, regulatório e judiciário na tentativa de desnaturar elementos desse tipo contratual. / At the end of the twentieth century, there was a global trend of privatizing public services that were rendered directly by the State, who was inefficient at addressing properly the citizens\' basic needs. Following such trend, the Brazilian electric sector, that had a billionaire debt, went through a complete restructure in the 90\'s that resulted in the privatization of the electricity generation, transmission, distribution and trading activities, as well as in the creation of regulatory mechanisms that incentivized efficiency and competition. By creating the trading activities, the electricity services that were rendered exclusively under a public regime started being rendered also by private parties, through power purchase agreements. Although part of the classic doctrine denies that the private regime may be applicable to the electricity services, this study shows that power purchase agreements executed in the Free Purchasing Environment are private. After confirming the theory that trading electricity under the private regime is constitutional, I conclude that electricity is a movable good and may perfectly be subject of private power purchase agreements, with a strong state regulation due to the public interest and essential characteristic of such good. Under the private law approach, I analyzed the basic elements of a power purchase agreement so as to, at the end, confirm the theory that electricity may be traded under private agreements and, as such, must prevail to any action of the Legislative, Regulatory and Judiciary Powers, against the elements of this kind of contract.

Durante um acidente em uma usina nuclear, a integridade do vaso pressurizado deve ser assegurada. Em resposta a um possível derretimento do combustível nuclear, a atual geração de usinas possui um sistema para a injeção de água potável na cavidade do vaso pressurizado com intuito de resfriar sua parede, prevenindo danos a sua estrutura e evitando o vazamento de material radioativo. Esse estudo considerou o uso de água marinha como refrigerante para inundar a cavidade do vaso pressurizado combinado com a fixação de um estrutura porosa em forma de grade em sua parede externa como meio de aprimorar a margem de segurança durante a contenção de acidentes. Experimentos de longa duração para a ebulição em piscina de água marinha artificial foram conduzidos em uma superfície circular de cobre plana com 30 mm de diâmetro. Foi encontrado um fluxo de calor crítico de 1; 6 MW/m2 sob pressão atmosférica. Esse valor é significantemente maior que aquele obtido (1; 0 MW/m2) nas mesmas condições experimentais. Foi verificado que os depósitos de sais marinhos podem aumentar a molhabilidade e a capilaridade da superfície de teste, aprimorando assim o fluxo crítico. Combinando a água marinha e a fixação da estrutura porosa sobre a superfície de teste, verificou-se um melhora no coeficiente de transmissão de calor e no fluxo de calor crítico de até 110 % (2; 1 MW/m2), quando comparado a água destilada na superfície limpa, sem a instalação da estrutura. Após os experimentos, foi identificado que muitos dos poros presentes nas superfícies da estrutura porosa encontravam-se bloqueados devido ao aglutinamento de sais marinhos. Isso levou a conclusão que o aumento no valor do fluxo crítico observado para a água marinha artificial ocorreu devido, principalmente, a separação das fases líquida e gasosa do fluido na região próxima a superfície de teste, efeito proporcionado pela forma de grade da estrutura porosa, e ao aumento da molhabilidade e capilaridade da superfície devido a formação dos depósitos marinhos. / During a severe nuclear power plant accident, the integrity of the reactor pressure vessel must be assured. In response to a possible fuel meltdown, operators of the current generation of nuclear power plants are likely to inject water into the reactor pressure vessel to cool down the reactor vessel wall, preserving its integrity and avoiding leakage of radioactive material. This study considers the use of seawater to flood a reactor pressure vessel combined with the attachment of a honeycomb porous plate (HPP) on the vessel outer wall as a way to improve the safety margins for in-vessel retention of fuel. In long-duration experiments, saturated pool boiling of artificial seawater was performed with an upward-facing plain copper heated surface 30 mm in diameter. The resulting value for critical heat flux (CHF) was 1; 6 MW/m2 at atmospheric pressure, a value significantly higher than the CHF obtained when the working fluid was distilled water (1; 0 MW/m2). It was verified that sea-salt deposits could greatly improve surface wettability and capillarity, enhancing the CHF. The combination of artificial seawater and an HPP attached to the heated surface improved the boiling heat transfer coefficient and increased the CHF up to 110% (2; 1 MW/m2) as compared to distilled water on a bare surface. After the artificial seawater experiments, most of the wall micropores of the HPP were clogged because of sea-salt aggregation on the HPP top and bottom surfaces. Thus, the CHF enhancement observed in this case was attributed mainly to the separation of liquid and vapor phases provided by the HPP channel structure and improvement of surface wettability and capillarity by sea-salt deposition.

"Electrohydrodynamic (EHD) pumping relies on the interaction between electrical and flow fields in a dielectric fluid medium. Advantages such as simple and robust design as well as negligible vibration and noise during operation make EHD conduction pumping suitable for various applications. This work investigates meso-scale EHD conduction pumping used as an active flow distribution control mechanism for thermal management systems. Two different scenarios are considered for this purpose: alteration of uniform flow distribution and flow maldistribution correction. Its capability of actively controlling the flow distribution is examined in terms of the value of applied potential for initiation of flow divergence or flow equalization and the flow rate difference between each branch. Experimental results confirm that the reverse pumping direction configuration of EHD pumping is more effective than the same pumping direction configuration. A fundamental explanation of the heterocharge layer development is provided for the effect of flow direction on EHD conduction pumping performance. This study also involves a macro-scale EHD conduction pump used as an alternative mechanism of mixing liquid within a storage tank, for example under low-g condition. A numerical analysis of a simplified model of the experimental setup is provided to illustrate the liquid mixing and thermal homogenization process. The experimental and numerical study provide fundamental understanding of liquid mixing and thermal homogenization via EHD conduction pumping. Liquid-vapor phase change phenomena are used as effective mechanisms for heat transfer enhancement and have many applications such as HVAC&R systems. With this in mind, two detailed studies in pool boiling and in-tube flow condensation are carried out. Specifically, nucleate pool boiling on nano-textured surfaces, made of alumina ceramic substrate covered by electrospun nanofiber, is experimentally investigated. Also, the role of surface roughness and orientation in pool boiling is experimentally characterized. The in-tube convective condensation of pure water in mini-channels under sub-atmospheric pressure is also experimentally explored. This study provides valuable information for the design of condensers in a vapor compression cycle of HVAC&R systems using water as the refrigerant, this process has zero global warming potential. "