Esta tese focaliza os itinerários (entendidos como uma sequência de operações que se sucedem no tempo) de catadores de materiais recicláveis integrantes de associações e cooperativas localizadas na região sul do Brasil. Estruturou-se em três arranjos. No primeiro, o trabalho de pesquisa se voltou à compreensão das influências recíprocas entre o campo ambiental e a atividade de reciclagem. No segundo, voltou-se aos modos através dos quais os catadores, desde suas vinculações com a atividade de reciclagem e com o campo ambiental, relacionam-se com variados discursos que os interpelam. Por fim, focalizou as práticas sociais (discursivas e não discursivas) utilizadas por esses sujeitos na (re)invenção de seus cotidianos e suas trajetórias de vida. A investigação foi desenvolvida através do acompanhamento in situ das atividades dos catadores e por meio de entrevistas semi-estruturadas. Além disso, recorreu à análise documental para a caracterização dos discursos com maior poder de interpelação junto aos catadores. No que tange aos atravessamentos entre o campo ambiental, a reciclagem e os catadores, os resultados interrogam o papel dessa intensa produção simbólica na (re)colocação social da atividade de reciclagem, assim como dos sujeitos que a animam. Sugerem que, a despeito da significativa ampliação do repertório simbólico desde o qual ambos – catador e reciclagem – vêm sendo pensados, as repercussões da incorporação do argumento ambiental para esses sujeitos, em especial sob a forma de oportunidades para reconstrução de si, ainda são pouco sensíveis. A descrição densa das práticas dos catadores, além disso, problematiza a ideia de que estas apenas se conformam às estruturas sociais preexistentes, reproduzindo-as acrítica e inconscientemente. O acompanhamento e a caracterização pormenorizada dessas práticas sublinham aquela sua dimensão criativa, inseparável da estrutura social é certo, mas não completamente determinadas por ela. As catadoras e os catadores de materiais recicláveis, através dos seus itinerários, desafiam-nos a repensar a rigidez dos lugares desde os quais oferecemos leituras acerca dos seus posicionamentos. Desafiam-nos igualmente a rever a rigidez dos lugares que resultam dessas leituras (e que de modo geral são utilizados para “aprisioná-los”). Decorre daí a necessidade, apresentada aqui como sugestão, de tornar mais fluido e móvel o lugar educativo desde o qual tanto as práticas educacionais, quanto as políticas públicas vem sendo pensadas e direcionadas a esses sujeitos. / This thesis focuses on the itineraries (understood as a sequence of operations that take place in time) of recyclable materials collectors members of associations and cooperatives located in southern Brazil. It is structured into three arrangements. In the first arrangement, the research geared toward the understanding of the reciprocal influences between the environmental field and recycling activity. In the second one, it geared toward the ways in which the waste collectors, from their linkages with the recycling activity and the environmental field, relate to various discourses that interpellate them. Finally, it focused on the social practices (discursive and non-discursive) used by these subjects in the (re) invention of their everyday life and their life path. The research was developed through the in situ monitoring of the waste pickers activities and through semi-structured interviews. Furthermore, it was resorted to documentary analysis to characterize the discourses with greater power of interpellation with the waste collectors. With regard to the crossings between the environmental field, recycling and waste collectors, the results interrogate the role of this intense symbolic production in the (re) placement of social recycling activity, as well as the subjects that animate it. It is suggested that despite the significant expansion of the symbolic repertoire from which both collector and recycling have being designed, the effects of the incorporation of the environmental argument for these subjects, particularly in the form of opportunities to rebuild themselves, are still poorly sensitive. The thick description of the practices of collectors also questions the idea that they just conform to existing social structures, reproducing them uncritically and unconsciously. The monitoring and detailed characterization of these practices emphasize its creative dimension, certainly inseparable from the social structure, but not completely determined by it. The women and men collectors of recyclable materials through their itineraries, challenge us to rethink the stiffness of the places from which we offer readings about their positionings. They also challenge us to revise the rigidity of the places that result from these readings (and they are generally used to "capture them"). Hence the need, presented here as a suggestion, to make it more fluid and movable the education place from which both educational practices and public policy have been designed and targeted to those subjects.

The photographer discusses the work in Exegesis, his Master of Fine Arts exhibition held at Slocumb Galleries, East Tennessee State University, Johnson City, Tennessee from October 29 through November 2, 2007. The exhibition consists of 19 large format color photographs representing and edited from a body of work that visually negotiates the photographer's home in East Tennessee. The formulation of a web of influence is explored with a focus on artists who continue to pertain to Brown's work formally and conceptually. Included are photographers Eugene Atget, Walker Evans, William Eggleston, and Mike Smith as well as the artist Joseph Cornell, the painter Robert Motherwell, and the poet Charles Wright. Other topics include a discussion of place, particularly one's home, as a resource and an envelope for a body of work. Included are images of the photographer's earlier work and a catalogue of the exhibition.

At the end of the Pleistocene and the beginning of the Holocene, between 12,000 and 10,000 years ago, humans began to spread throughout North America and into many areas of Florida. These first Floridians are known as Paleoindians, and their culture is largely defined by their lithic assemblage, which includes the well known Clovis point. As the Pleistocene ice age came to a close glaciers melted, rivers experienced a drastic increase in water volume and the landmass of Florida began to shrink as the sea level in the Gulf of Mexico rose. This event likely submerged many early Paleoindian sites in coastal areas, and the only sites known now are usually found in river valleys. This research will examine the distribution of Paleoindian sites in the Apalachicola River Valley of northwest Florida in terms of environmental characteristics, namely distance to river and site elevation. Using data from known sites and from four artifact collectors, this research will show that Paleoindian sites cluster along the Chipola River, the major tributary of the Apalachicola River, and will also argue that it is far more beneficial for archaeologists to work with artifact collectors and document their vast amounts of data than to shun them and deem their data questionable and their methods unethical.

No description available.

Abstract For a long time in our society there has been a minority group, e.g. individual recycle material collectors, curio collectors, and recycle businessmen, living on collection and trading of recycle material. Particularly in recent years with the promotion champagne of environmental protection policy, there is an increasing trend in the number of people involved in this business. The society reacts both positively and negatively about such recycling business. The positive view comes from the environmental protection institution¡¦s affirmation about the reuse of recycled material, whereas the negative view is concerned about the messy environment created by the recycling method and process. It is an undisputable fact that their existence in residential and commercial area is violating the regulations of urban development plan. This paper discovers there are differences in opinion between the EPA authority and the Urban Development authority in the applicable regulations about owners of recycle business moving into industrial estate while investigating it¡¦s legality from the position of public sector. The methods of managing existing recycle business among the different local governments are also quite different. For instance, while the central EPA authority frequently prepares budgets in an effort to improve the image of the recycle business, the local urban development bureaus prescribe them for the reason of violating the regulations of urban development plan, such as piling up of wastes, etc. On the other hand, looking at the value of its existence from the economic benefit angle shows that the recycled waste cleared by the recycling business is 2.5 times more efficient than that of the public sector. Such economic benefit is clearly visible. Though this study covers only the Kaohsiung metropolitan area, the problem of these under sized waste recyclers is no doubt a nationwide issue. It is hoped that the investigation and analysis of this paper in the problems arise from the recycling business could benefit the business owners in economy of scale and profit analysis as well as the public sectors as a reference in the design of related laws and regulations.

In this study, the theoretical performance of a concentrating solar thermal electric system (CSTES) using a field of parabolic trough collectors (PTC) is investigated. The commercial software TRNSYS and the Solar Thermal Electric Components (STEC) library are used to model the overall system design and for simulations. The model was constructed using data from the literature for an existing 30-MW solar electric generating system (SEGS VI) using PTC&rsquo / s in Kramer Junction, California. The CSTES consists of a PTC loop that drives a Rankine cycle with superheat and reheat, 2-stage high and 5-stage low pressure turbines, 5-feedwater heaters and a dearator. As a first approximation, the model did not include significant storage or back-up heating. The model&rsquo / s predictions were benchmarked against published data for the system in California for a summer day. Good agreement between the model&rsquo / s predictions and published data were found, with errors usually less than 10%. Annual simulations were run using weather data for both California and Antalya, Turkey. The monthly outputs for the system in California and Antalya are compared both in terms of absolute monthly outputs and in terms of ratios of minimum to maximum monthly outputs. The system in Antalya is found to produce30 % less energy annually than the system in California. The ratio of the minimum (December) to maximum (July) monthly energy produced in Antalya is 0.04.

Oberflächennahe Erdwärmekollektoren, insbesondere horizontale Erdwärmekollektoren, stellen eine wirtschaftlich und energetisch sinnvolle Wärmequellenanlage für Wärmepumpen dar. Auf Grund mangelnder wissenschaftlicher Untersuchungen in der Vergangenheit wurde deren Leistungsfähigkeit bisher jedoch kaum ausgenutzt. Des Weiteren fühlten sich die Planer bei der Auslegung oft unsicher, da es kaum verlässliche Auslegungsrichtlinien gab. In dieser Arbeit werden ein numerisches und ein analytisches Rechenmodell vorgestellt, mit denen Jahresverläufe der charakteristischen Soletemperaturen und der Eisbildung realitätsnah simuliert werden können. Mit Hilfe dieser Rechenmodelle wurde unter Berücksichtigung unterschiedlicher Bodentypen und Klimazonen die hydraulische und geometrische Auslegung anhand der Kriterien Energieeffizienz, Wirtschaftlichkeit, Betriebssicherheit und Umweltbeeinflussung bewertet, optimiert und Einsatzgrenzen klar ausgearbeitet. Daneben wurde auch die Auslegung für Kollektoren bei Spitzenlastnutzung und Sonderbauformen wie Grabenkollektoren und Erdwärmekörben untersucht.

No description available.

<p>Fuel cells are promising candidates for converting chemical energy into electrical energy. The Molten Carbonate Fuel Cell (MCFC) is a high temperature fuel cell that produces electrical energy from a variety of fuels containing hydrogen, hydrocarbons and carbon monoxide. Since the waste heat has a high temperature it can also be used leading to a high overall efficiency.</p><p>Material degradation and the cost of the components are the problems for the commercialisation of MCFC. Although there are companies around the world starting to commercialise MCFC some further cost reduction is needed before MCFC can be fully introduced at the market.</p><p>In this work, alternative materials for three different components of MCFC have been investigated. The alternative materials should have a lower cost compared to the state-of-the-art materials but also meet the life-time goal of MCFC, which is around 5 years. The nickel dissolution of the cathode is a problem and a cathode with lower solubility is needed. The dissolution of nickel for three alternative cathode materials was investigated, where one of the materials had a lower solubility than the state-of-the-art nickel oxide. This material was also tested in a cell and the electrochemical performance was found to be comparable with nickel oxide and is an interesting candidate.</p><p>An inexpensive anode current collector material is also desired. For the anode current collector, the contact resistance should be low and it should have good corrosion properties. The two alternative materials tested had low contact resistance, but some chromium enrichment was seen at the grain boundaries. This can lead to a decreased mechanical stability of the material. In the wet-seal area, the stainless steel used as bipolar/separator plate should be coated. An alternative process to coat the stainless steel, that is less expensive, was evaluated. This process can be a suitable process, but today, when the coating process is done manually there seems to be a problem with the adherence.</p><p>This work has been a part of the IRMATECH project, which was financed by the European Commission, where the partners have been universities, research institutes and companies around Europe.</p>

Development of alternative cathodes that have high capacity and long cycle life at an affordable cost is critical for next generation rechargeable batteries to meet the ever-increasing requirements of global energy storage market. Lithium-sulfur batteries, employing sulfur cathodes, are increasingly being investigated due to their high theoretical capacity, low cost, and environmental friendliness. However, the practicality of lithium-sulfur technology is hindered by technical obstacles, such as short shelf and cycle life, arising from the shuttling of polysulfide intermediates between the cathode and the anode as well as the poor electronic conductivity of sulfur and the discharge product Li2S. This dissertation focuses on overcoming some of these problems. The sulfur cathode involves an electrochemical conversion reaction compared to the conventional insertion-reaction cathodes. Therefore, modifications in cell-component configurations/structures are needed to realize the full potential of lithium-sulfur cells. This dissertation explores various custom and functionalized cell components that can be adapted with pure sulfur cathodes, e.g., porous current collectors in Chapter 3, interlayers in Chapter 4, sandwiched electrodes in Chapter 5, and surface-coated separators in Chapter 6. Each chapter introduces the new concept and design, followed by necessary modifications and development. The porous current collectors embedded with pure sulfur cathodes are able to contain the active material in their porous space and ensure close contact between the insulating active material and the conductive matrix. Hence, a stable and reversible electrochemical-conversion reaction is facilitated. In addition, the use of highly porous substrates allows the resulting cell to accommodate high sulfur loading. The interlayers inserted between the pure sulfur cathode and the separator effectively intercept the diffusing polysulfides, suppress polysulfide migration, localize the active material within the cathode region, and boost cell cycle stability. The combination of porous current collectors and interlayers offers sandwiched electrode structure for the lithium/dissolved polysulfide cells. By way of integrating the advantages from the porous current collector and the interlayer, the sandwiched electrodes stabilize the dissolved polysulfide catholyte within the cathode region, resulting in a high discharge capacity, long-term cycle stability, and high sulfur loading. The novel surface-coated separators have a polysulfide trap or filter coated onto one side of a commercial polymeric separator. The functional coatings possess physical and/or chemical polysulfide-trapping capabilities to intercept, absorb, and trap the dissolved polysulfides during cell discharge. The functional coatings also have high electrical conductivity and porous channels to facilitate electron, lithium-ion, and electrolyte mobility for reactivating the trapped active material. As a result, effective reutilization of the trapped active material leads to improved long-term cycle stability. The investigation of the key electrochemical and engineering parameters of these novel cell components has allowed us to make progress on (i) understanding the materials chemistry of the applied functionalized cell components and (ii) the electrochemical performance of the resulting lithium-sulfur batteries. / text