Water heating in a typical home in the U.S. accounts for a significant portion (between 14% and 25%) of the total home's annual energy consumption. The objective of considerably reducing the home's energy consumption from the utilities calls for the use of onsite renewable energy systems. Integral Collector Storage (ICS) solar domestic water heating systems are an alternative to help meet the hot water energy demands in a household. In order to evaluate the potential benefits and contributions from the ICS system, it is important that the parameter values included in the model used to estimate the system's performance are as accurate as possible. The overall heat loss coefficient (Uloss) in the model plays an important role in the performance prediction methodology of the ICS. This work presents a new and improved methodology to determine Uloss as a function of time in an ICS system using a systematic optimal control theoretic approach. This methodology is based on the derivation of a new nonlinear state space model of the system, and the formulation of a quadratic performance function whose minimization yields estimates of Uloss values that can be used in computer simulations to improve the performance prediction of the ICS system, depending on the desired time of the year and hot water draw profile. Simulation results show that predictions of the system's performance based on these estimates of Uloss are considerably more accurate than the predictions based on current existing methods for estimating Uloss.

[pt] Esta dissertação busca estudar quais foram os impactos socioeconômicos e ambientais, ocorridos na vida dos catadores de materiais recicláveis que atuavam diretamente no Aterro Metropolitano de Jardim Gramacho, que, após decorridos trinta anos, teve seu funcionamento encerrado. Nossa pesquisa teve como objetivo qualificar a presença das políticas públicas como uma das vias de acesso ao processo sustentável para esses trabalhadores e avaliar se o que é projetado tem os impactos desejados e efetivos na vida desse grupo social ou se é ineficiente, já que não contariam mais com o espaço para desenvolver a atividade de catação na busca da própria subsistência, bem como de seus familiares. Para fundamentar este estudo buscamos, através de levantamento bibliográfico sobre o tema, pesquisa documental, observação participante e da fala dos sujeitos, entrevistas semiestruturadas, descrever o processo atual de trabalho, ponderando perdas e ganhos viabilizados pelo apoio governamental e, pela nova forma de tratar a separação e venda de material reciclável, prevista na Lei 12.305/2010 – Política Nacional de Resíduos Sólidos (PNRS) bem como, nos benefícios da Política de Assistência Social que, nem sempre atendem na mesma proporção a necessidade dos beneficiários, tornando-os cada vez mais excluídos dos bens e serviços e, por vezes, incluídos perversamente. O estudo proposto examinou o universo dos catadores que atualmente desenvolvem suas atividades de separação de resíduos no Polo de Reciclagem, espaço cedido pela Secretaria de Estado do Ambiente do Rio de Janeiro (SEA), no próprio sub-bairro onde funcionava o lixão, cujo objetivo é a continuação da atividade de separação de resíduos, porém de forma salubre, seletiva e ordenada na garantia da manutenção de trabalho e renda para todos. / [en] Concern for the environment and also an interest in the discovery of new actions towards sustainable development1 are extremely relevant factors for modern society. There is a need for constant consideration of this issue, as Brazilian policies are based on a model of developmentalist development, while policies for assistance are based on a similar perspective. This is what led me to embark on this study, looking at the social and environmental issue from the standpoint of interdisciplinarity, as I believe that there is an underlying social function under whatever perspective is considered. Even though the current reality of the recyclables market allows one to envisage a sustainable horizon which is economically attractive for large businesspeople in the industrial segment, in stark contradiction it denies access to essential goods and services to the very people who are part of the production chain, the waste scavengers or catadores. This is initially justified by the devaluation of the activity which is carried out, an activity which is often considered unhealthy, dangerous, arduous, and generating less value for the potential employer and less profit. This, together with the fact that most of the workers have a low level of schooling, means that this category of workers has become stigmatised as unable to manage their own business.

<p>Flotation is a critical operation in the isolation of valuable minerals from natural ore. Before flotation, chemical collectors are routinely added to ground ore slurries. Collectors selectively bind to mineral-rich particles, increasing their hydrophobicity thus promoting selective flotation. Conventional collectors are small surfactants with a short hydrocarbon tail (2-6 carbons) and a head group, such as xanthate. In this work, much larger hydrophobic polystyrene nanoparticles are evaluated as potential flotation collectors. Experiments involving both clean model mineral suspensions and complex ultramafic nickel ores confirm that conventional water-soluble molecular collectors could be partially or completely replaced by colloidal hydrophobic nanoparticle flotation collectors.</p> <p>The ability of nanoparticles to induce flotation has been demonstrated by floating hydrophilic, negatively charged glass beads with cationic polystyrene nanoparticle collectors. Mechanisms and key parameters such as nanoparticle hydrophobicity and nanoparticle adsorption density have been identified. Electrostatic attraction promotes the spontaneous deposition of the nanoparticles on the glass surfaces raising the effective contact angle to facilitate the adhesion of beads to air bubbles. The pull-off force required to detach a glass sphere from the air/water interface of a bubble into the water was measured by micromechanics. Coating with nanoparticles allows the beads to attach remarkably firmly on the air bubble. As little as 10% coverage of the bead surfaces with the most effective nanoparticles could promote high flotation efficiencies, whereas conventional molecular collector requires 25% or higher coverage for a good recovery. Contact angle measurements of modified glass surfaces with a series of nanoparticles that covered a range of surface energies were used to correlate the nanoparticle surface properties with their ability to promote flotation of glass beads. Factors influencing nanoparticle deposition on glass, such as nanoparticle dosage, nanoparticle size, conditioning time have been investigated with a quartz crystal microbalance (QCM). Deposition kinetics has been analyzed according to Langmuir kinetics model.</p> <p>Surface functionalized nanoparticles enhance the ability of nanoparticle collectors to selectively deposit onto surfaces of the desired mineral particles in the presence of gangue materials. Poly (styrene-co-vinylimidazole) based nanoparticle collectors have been developed to selectively deposit onto nickel mineral (pentlandite) in the presence of Mg/Si slime. Flotation tests of ultramafic nickel ores with these nanoparticle collectors have shown improvements in both pentlandite recovery and selectivity.</p> / Doctor of Philosophy (PhD)

Houston modern architect, Karl Kamrath (1911-1988), collected books, periodicals, and archival material that document the career and legacy of Frank Lloyd Wright. Kamrath identified himself as a collector of Wright and a devotee to the principles set forth by the master architect. In this thesis, I present Kamrath’s collection by organizing the materials by subject, considering how Kamrath marked books and journals, and drawing connections between his collecting interests and his architectural work. Kamrath collected and consumed information on Wright and organic architecture and then presented his own articulations of the principles in built form. His interest in organic architecture was evident in his projects that blended into the landscape and satisfied the individual needs of each client. The purpose of this thesis is to contribute to the story on Karl Kamrath, adding the details of the collection he donated to The University of Texas at Austin. / text

En tant que savant et haut-fonctionnaire Ruan Yuan est une figure éminente de la fin de la dynastie Qing (1644-1911). Sa collection, principalement composée d’objets antiques, bronzes rituels, briques et tuiles, est modelée d’après les traditions de l’épigraphie chinoise ou jinshi xue. La première partie de la thèse est consacrée à l’analyse de la collection. Sa typologie et sa formation sont le reflet de l’approche scientifique des objets antiques adoptée par Ruan Yuan. Ses méthodes, qui reposent sur les développements récents de la phonologie, sont liées à l’essor de l’école des « vérifications et des preuves », ou kaozheng xue. Parallèlement, les objets de collection, en particulier les pierres, sont considérés comme des objets de délectation qui peuvent être transformés en encriers ou en écrans qui reflètent l’imagination de Ruan Yuan. La seconde partie de la thèse décrit comment les pratiques de collectionneur de Ruan Yuan s’inscrivent dans un processus de transmission des vestiges culturels. Les méthodes de compilation des textes ont été adaptées par Ruan Yuan afin de publier les inscriptions antiques des provinces où il exerçait en tant que fonctionnaire. Son utilisation des techniques de conservation, comme le montage des peintures, et des techniques de reproduction, comme l’estampage ou la gravure, ont permis de préserver les originaux et de diffuser leur image. Au-delà de la transmission de sa propre collection, principalement conçue comme un héritage familial, la création de bibliothèques dans les temples célèbres, qui dépassent les limites de la propriété privée, est une étape importante vers la définition moderne du patrimoine culturel en Chine. / As a scholar and an official, Ruan Yuan is a prominent figure of the late Qing dynasty (1644-1911). His collection of artifact, which focuses mainly on antiques like ritual bronzes, bricks and tiles, is shaped by the traditions of Chinese epigraphy or jinshi xue. The first part of the dissertation is devoted to the analysis of the collection. Its typology and formation reflect the scientific approach of antiques adopted by Ruan Yuan. His methods, which rely on the recent developments in phonology, are related to the rise of the evidential research school or kaozheng xue in XVIIIth century China. Besides this scientific approach, collected artifacts, especially stones, are also considered as objects of delectation which can be transformed into inkstones or screens which reflect the imagination of their owner. The second part of the dissertation describes how Ruan Yuan’s collecting practices are part of a larger process of conservation and transmission of cultural relics. The methods of collation of texts used to realize encyclopedia have been adapted by Ruan Yuan to publish the ancient inscriptions on metal and stone from the provinces where he served as an official. His use of conservation techniques, like the mounting of paintings, and of reproduction techniques, like the rubbing or carving of steles, allowed to preserve originals and to spread their images among scholars. Beyond the transmission of his own collection, mainly conceived as a family legacy, the creation of libraries in famous temples, which exceeded the boundaries of private property, is an important step toward the assertion of a modern definition of cultural heritage in China.

We show full Li/S cells with the use of balanced and high capacity electrodes to address high power electro-mobile applications. The anode is made of an assembly comprising of silicon nanowires as active material densely and conformally grown on a 3D carbon mesh as a light-weight current collector, offering extremely high areal capacity for reversible Li storage of up to 9 mAh/cm(2). The dense growth is guaranteed by a versatile Au precursor developed for homogenous Au layer deposition on 3D substrates. In contrast to metallic Li, the presented system exhibits superior characteristics as an anode in Li/S batteries such as safe operation, long cycle life and easy handling. These anodes are combined with high area density S/C composite cathodes into a Li/S full-cell with an ether- and lithium triflate-based electrolyte for high ionic conductivity. The result is a highly cyclable full-cell with an areal capacity of 2.3 mAh/cm(2), a cyclability surpassing 450 cycles and capacity retention of 80% after 150 cycles (capacity loss <0.4% per cycle). A detailed physical and electrochemical investigation of the SiNW Li/S full-cell including in-operando synchrotron X-ray diffraction measurements reveals that the lower degradation is due to a lower self-reduction of polysulfides after continuous charging/discharging.

Trois techniques de mesure différentes ont été utilisées pour étudier la distribution des fluides dans un lit fixe : la tomographie à fils, le collecteur de liquide et un ensemble de thermistances. La tomographie à fils, dont la première application dans le cadre des lits fixes est décrite ici, a permis, tout comme le collecteur de liquide, d’obtenir des résultats intéressants concernant l’influence de paramètres tels que la distribution initiale, le type de chargement et les débits de fluides sur la distribution du liquide. L’étude a notamment montré l’importance de bien définir la maldistribution de liquide en termes de la grandeur mesurée et a apporté un regard critique vis-à-vis des consensus généraux concernant l’effet sur la distribution de liquide de paramètres tels que le débit de gaz (dont les expériences ont montré qu’elle dépend du distributeur utilisé) et le type de chargement (l’hypothèse selon laquelle le chargement dense disperse mieux le liquide dans la direction radiale par rapport au chargement lâche n’a pas été vérifié). Une étude réalisée en régime à haute interaction a permis aussi d’observer la relation étroite qui existe entre la distribution initiale et le régime d’écoulement / Three different measuring techniques were used to study the fluid distribution inside a trickle-bed reactor: the wire mesh tomography, the liquid collector and a set of thermistors. The liquid collector and specially the wire mesh tomography, whose first application in trickle bed reactors is described here, yielded interesting results concerning the influence of variables such as the initial liquid distribution, the loading method and the fluid flow rates on liquid maldistribution. Among the main observations, the study illustrates the importance of well defining liquid maldistribution in terms of the measured quantity and prompts to some caution when referring to some “normally accepted facts” like the advantages in terms of liquid distribution obtained when increasing the gas flow rate (which depends, according to this study, on the quality of initial liquid distribution) or when using a dense loading of the catalyst (the hypothesis according to which, compared with a sock loading, dense loading favors radial dispersion was not verified by the study). Also, a study performed under high interaction conditions showed the intimate relationship between the inlet distribution and the flow regime observed inside the reactor

This Master thesis, in collaboration with Morgonsol Väst AB, was completed as a part of the Solar Energy engineering program at Dalarna University. It analyses the electrical and thermal performance of a prototype PVT collector developed by Morgonsol Väst AB. By following the standards EN 12975 and EN ISO 9806 as guides, the thermal tests of the collector were completed at the facility in Borlänge. The electrical performance of the PVT collector was evaluated by comparing it to a reference PV panel fitted next to it. The result from the tests shows an improved electrical performance of the PVT collector caused by the cooling and a thermal performance described by the linear efficiency curve ηth=0.53-21.6(Tm-Ta/G). The experimental work in this thesis is an initial study of the prototype PVT collector that will supply Morgonsol Väst with important data for future development and research of the product.

Este trabalho propõe a modelação matemática da perda de carga e da remoção de turbidez e de partículas na filtração direta ascendente baseada nos modelos que descrevem macroscopicamente o processo de filtração. Os modelos incluem o mecanismo de desprendimento de partículas do meio filtrante e a alteração da porosidade do material retido durante o processo de filtração. Foram propostos dois modelos: o monodisperso e o polidisperso. Tais modelos foram adaptados para a aplicação à filtração direta ascendente em material granular de areia grossa e pedregulho a partir de modelos para filtração descendente. Objetivou-se a identificação da influência do vetor gravitacional na parcela de eficiência por sedimentação gravitacional na proposição de modelos de eficiência inicial de remoção na filtração ascendente. Três concepções para quatro modelos de eficiência inicial de remoção foram propostas e aplicadas à filtração ascendente. Duas destas concepções foram adaptadas do original da filtração em aerossóis para escoamento ascendente e a outra a partir de modelos para escoamento descendente. Os resultados do modelo monodisperso apresentaram boa aderência aos dados experimentais obtidos da filtração ascendente em um sistema de dupla filtração mediante uma análise estatística com base nos valores dos coeficientes de correlação não linear. O modelo polidisperso também foi analisado, não tendo alcançado, entretanto, a mesma eficiência do modelo monodisperso. Os valores de eficiência inicial de remoção para a filtração direta ascendente calculados pela concepção proposta neste trabalho indicam razoável adequação aos modelos de filtração e apresentam-se coerentes e consistentes com os valores experimentais e com a teoria da trajetória. / This work proposes mathematical models to predict the head loss, the turbidity and particles removal in up flow direct filtration based on the models that describe macroscopic filtration process. The models include the mechanism of particles detachment from the granular medium and the porosity change of the retained material during the filtration process. Two models were proposed: the monodisperse one and the polidisperse one. These models were used for up flow direct filtration in granular material of coarse sand and gravel based on down flow filtration models. The identification of the influence of the gravitational vector was aimed in the efficiency portion by gravitational sedimentation in the proposition of models of initial efficiency collector in the up flow filtration. Three conceptions of four initial efficiency collector models were proposed and applied to up flow filtration. Two of those conceptions were adapted from up flow aerosols filtration and another one was based on down flow models. The results of the monodisperse model presented good adherence to the up flow experimental data from a double filtration system by means of a statistical analysis with based on coefficients of non lineal correlation values. The polidisperse model was also analyzed, however, it did not provide the same efficiency of the monodisperse model. The initial efficiency removal values for the up flow direct filtration calculated by the proposed models indicated reasonable suitability to the filtration models and they come coherent and consistent with the experimental values and with the theory of trajectory analysis.

A presente Dissertação é um estudo a respeito da problemática da utilização dos Sistemas de Aquecimento Solar Térmico para Aquecimento de Água com Coletores Planos em Circuito Direto, no crítico contexto da construção civil paulista para o ponto de vista da Arquitetura e do Urbanismo. Apesar do potencial solar do país e do padrão construtivo dos condomínios horizontais fechados da Região Metropolitana de São Paulo (RMSP), ainda não há regulamentação do uso do aquecimento solar térmico em alguns de seus municípios-sede. Atualmente tem havido a adesão espontânea ao sistema por parte de moradores das residências desses condomínios, decorrente da busca da redução dos gastos e da crescente conscientização ambiental e divulgação da tecnologia. Porém, ainda há necessidade de uma relação mais sistêmica dos coletores solares com a totalidade dos requisitos da edificação e do meio urbano, mesmo em se tratando da legislação específica. Buscando uma constribuição, aqui se propõe um modelo de estudo dos coletores baseado em escalas construtivas que, juntamente com a compreensão multidimensional do assunto, desafiam a atual dicotomia entre as ferramentas de qualidade e a sustentabilidade do ambiente construído. / The present work studies the problematic of using Solar Hot Water Systems by Direct Circuit, among the critics characteristics of civil construction in the State of São Paulo, Brazil. The point of view is of Architecture and Urban Planning. In spite of the high Brazilian levels of solar irradiation and the constructive pattern of horizontal closed condominiums of the metropolitan region of São Paulo (Brazil), which possess a large concentration of high incoming households, use of solar water heating is still not regulated in some of its comprising municipalities. Nowadays, the search for savings, diffusion of related technologies and raising environmental awareness have led to voluntary uptaking of such systems. Yet, regulation of solar collectors still lacks relating to certification of sustainable building practices, which does not relate to architectonic factors, in particular to main urbanistic features present in each given installation site. This work proposes an architectonic scale based model of studying it in order to pursuit the end of dichotomy between quality and sustainability.