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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

Treatment of oil refining wastewater by pilot-scale constructed wetland systems

Shih, Pei-Yu 18 July 2001 (has links)
In most cases, data from petroleum industry wetland studies indicate that treatment wetlands are equally or more effective at removing pollutants from petroleum industry wastewaters than from other types of wastewater. In this study, we discussed the treatment efficiencies of oil-refinery industry wastewater by pilot-scale constructed wetland systems .The constructed wetland systems were one free water surface system filled with the sandy media and one subsurface flow system filled with the gravel media operated in parallel. Each system planted with Phragmites communis. The hydraulic retention time for the treatment wetland was controlled in turn at 0.96, 0.48, and 0.72 days. The experimental results showed that all of these contaminants could be reliably removed from wastewater by treatment wetland, especially the FWS. The effluents from the constructed wetland systems reusing and recovering were feasible.
2

Stream-less : A flexible and social solution for food / Strömlöst : En flexibel och social lösning för mat utan elektricitet

Wågberg, Ida January 2023 (has links)
The aim of the project is to investigate how a residential area could be more resilient to disasters. I have explored how this could be done by reusing or developing what already exists. The intention is to show how a residential area could be strengthened by such redesign, in collaboration with the residents. The project is located at Kandidatvägen, in the southern parts of Ålidhem in Umeå. In the area, different hubs are designed, with different functions related to our basic needs such as food, water, or sleep. One of these hubs, for food production and storage without electricity, is illustrated in detail within the project. A common room (kvarterslokal) is transformed and equipped with food solutions to function without electricity. Spatially, walls are removed and folding doors are applied to the facade to create a more flexible space. The kitchen is mobile and can be used indoors and outdoors. The space is also provided with foldable furnitures and storage. In the inner courtyard, a greenhouse and a cultivation area for food production are located. The residents could gather in the food hub if an electricity interruption occurs, and in ‘normal’ times, when people can use their apartments as usual, the space could be used in a similar way as today; as a social space for different activities. But with the new design, the space will be more flexible and enhance its usage.
3

An Investigation into Water Usage and Water Efficient Design for Persian Gardens

Ansari, Shaghayegh Moalemzadeh January 2015 (has links)
Investigation and research into the Persian Gardens, leading this project into a step that these World Heritage Sites might have been known as sustainable construction, but the fact that water scarcity of their region is a serious threaten for all these amazing Gardens. Thus, enhancing and improving these gardens by merging, adding and adapting todays technologies can make them considered as constructions with water and energy conservation design. Based on nowadays world environment concerns, recognizing renewable and non-renewable sources of energies in a region or site can cause a miracle. Since, almost all Persian Gardens located in regions with arid and semi-arid climate, water poverty as a biggest issue and nonrenewable energy should be included as a problematic concern. There are many available active and passive strategies that can be applied in these heritage sites which decrease water consumption either directly or indirectly. Such as water harvesting, greywater reuse, photovoltaic panels and material changes. Water known as a vital element of each garden for irrigation purposes, but in Persian Garden water is more than a functional element. Thus, finding a way to provide and recycle water beside the underground sources is necessary. Subterranean, springs and wells are resources of water for Persian gardens which renew so slowly or non-renew these days. Being so close to a city with considerable population lunches and idea of using greywater for irrigation in these gardens. In this research, the doable options for energy conservation design for these sites will be discussed, then comparing some case studies in all over world where greywater reusing water system for irrigation is happening will be next step. In conclusion, greywater reusing system in urban scale in order to irrigate a filed or garden will be investigate on a Shazdeh Garden as a main case study of this research.
4

Quantifying the Impact of Circular Economy Applied to the Built Environment: A Study of Construction and Demolition Waste to Identify Leverage Points

January 2019 (has links)
abstract: The built environment is responsible for a significant portion of global waste generation. Construction and demolition (C&D) waste requires significant landfill areas and costs billions of dollars. New business models that reduce this waste may prove to be financially beneficial and generally more sustainable. One such model is referred to as the “Circular Economy” (CE), which promotes the efficient use of materials to minimize waste generation and raw material consumption. CE is achieved by maximizing the life of materials and components and by reclaiming the typically wasted value at the end of their life. This thesis identifies the potential opportunities for using CE in the built environment. It first calculates the magnitude of C&D waste and its main streams, highlights the top C&D materials based on weight and value using data from various regions, identifies the top C&D materials’ current recycling and reuse rates, and finally estimates a potential financial benefit of $3.7 billion from redirecting C&D waste using the CE concept in the United States. / Dissertation/Thesis / Masters Thesis Civil, Environmental and Sustainable Engineering 2019
5

Formula??o e caracteriza??o de mat?rias-primas para revestimento cer?mico Semi-Poroso com adi??o de chamote de telhas / Formulation and characterization of raw materials for Semiporous ceramic coating and roofing tile Chamote

Castro, Raimundo Jos? de Sousa 26 March 2008 (has links)
Made available in DSpace on 2014-12-17T14:06:46Z (GMT). No. of bitstreams: 1 RaimundoJSC.pdf: 1462699 bytes, checksum: cac59ec25bd8ba4355dbea19489431b4 (MD5) Previous issue date: 2008-03-26 / The ceramics industry in Piau? is nowadays with 55 industries where 11 are in Teresina which is the mainstream of the state, producing 55 million shingles; in which 10 % is of this production is wasted being sometimes thrown on the margins of rivers, roads and highways provoking an environmental degradation. The main goal of this work is to verify the potential of producing semi porous ceramic using grog of shingles, on the first part of this work bodies-of-proof were produced from a basic formula of an industry, doping it with 5 %, 10 %, 15 % and 20 % in mass and in the second part of this work some bodies-of-proof were produced from a formula where one raw material was substituted by 50 % of grog and another substituting it all by grog, bodies-of-proof made of a basic formula previously announced was used for experiment control.The grog and the raw materials were characterized by: particle size analysis , thermal differential analysis, X ray diffraction , X ray fluorescence, an thermal gravimetric analysis and rational analyses. The bodies-of-proof were sintetisized in an industrial oven obeying the normal cycle adopted by an industry, with peak temperatures of 1135 oC and a fast burning cycle of 25 minutes having as energetic fuel liquefied petroleum gas . The pieces that were obtained by this were submersed in rehearsed physics of: water absorption of, apparent specific mass, apparent porosity, lineal retraction, rupture tension to the flexural and dilatometry; mineralogical analysis for X ray diffraction; and microstructural for electronic microscope of sweeping. For all the formulas with addition of grog, superior priorities to the requested by the requirements for semi porous and for the formula to F2-2,5 superior priorities to standard formulas which justifies the incorporation of the shingles in mass for the semi porous ceramic / A ind?stria de cer?mica vermelha Piauiense, atualmente com 55 ind?strias onde 11 somente em Teresina sendo o maior p?lo do Estado, produz pouco mais de 55 milh?es de telhas, das quais aproximadamente 10 % dessa produ??o s?o desperdi?adas sendo ?s vezes jogadas ?s margens dos rios e estradas, provocando uma degrada??o ambiental. O objetivo deste trabalho ? verificar a potencialidade de se produzir revestimento cer?mico semi-poroso utilizando chamote de telhas, na primeira parte do trabalho foram produzidos corpos-de-prova a partir da formula??o b?sica de uma ind?stria de revestimento, dopando-a com 5 %, 10 %, 15 % e 20 % em massa, e uma segunda parte deste trabalho foram produzidos corpos-de-prova a partir de uma formula??o onde se substitu?a uma das mat?rias-prima por 50 % de chamote e outra substituindo a mesma totalmente por chamote, sendo usado para controle do experimento corpos-de-prova confeccionados a partir de uma formula??o b?sica citada anteriormente. O chamote e as mat?rias-prima foram caracterizados por: an?lise granulom?trica, an?lise t?rmica diferencial, an?lise termogravim?trica difra??o de raios X, fluoresc?ncia de raios X, e an?lise racional. Os corpos-de-prova foram sinterizados em forno industrial de rolo, obedecendo ao ciclo adotado por uma ind?stria de revestimento, com temperatura de pico igual a 1135 ?C e ciclo de queima r?pido de 25 min, tendo como matriz energ?tica o g?s liquefeito de petr?leo. As pe?as assim obtidas foram submetidas aos ensaios f?sicos de: absor??o de ?gua, massa espec?fica aparente, porosidade aparente, retra??o linear, tens?o de ruptura ? flex?o e dilatometria; an?lise mineral?gica por difra??o de rios X; e microestrutural por microsc?pio eletr?nico de varredura. Obteve-se para todas as formula??es com adi??o de chamote, propriedades superiores ?s das exigidas pelas normas em vigor para revestimento semi-poroso e para a formula??o F2-2,5 propriedades superiores ? formula??o padr?o o que justifica a viabilidade da incorpora??o do rejeito de telhas em massa para revestimento cer?mico semi-poroso
6

Office chairs in circular business models

Askew, Robin, Carlberg, Stefan January 2016 (has links)
This is a master’s thesis project of 30 credits written with guidance from the Swedish research institute ICT Viktoria and Industrial Ecology at KTH. This thesis is conducted by two students at KTH, one with a background in Mechanical Engineering and Industrial Ecology and the other with a background in Energy and Environmental Technology. This study focuses on circular economy linked to the furniture industry in Sweden and how the transition from theoretical to practical concepts can be improved. The methods of this thesis consist of three semi-structured interviews, a survey and an analytical comparative literature review. The interviews, survey and literature review is analyzed with the purpose of finding important criteria relevant for office chairs in circular business models. The interviews are performed face-to-face with three different key persons; an office supply manager, a CEO at a refurbishing company and a product manager. The study focuses on product design within the Swedish furniture industry although some aspects regarding circular business models, logistics and psychological values are included. The results are design criteria for office chairs in circular business models and a design evaluation program for the industry built on these. The program, based on multi criteria analysis, can help reduce the gap between theory and practice of how circular economy should be implemented in the industry. By giving early feedback during the design phase on how well an office chair and a company’s structure meet circular economy criteria the authors hope to ease and speed up this transition. The main characteristics of an office chair designed for circular business models are: Durable Easy to service Adaptable Modular Homogeneous material composition in modules Although the transition to circular business models can be a comprehensive process the authors believe that if furniture manufacturers would integrate circular business models for office chairs into their business structure this would be both economically viable and highly beneficial for their environmental profile which can strengthen their position on the market.
7

Uchváceni odpadem: etnografická studie nejen okolo velkoobjemového kontejneru / Captived by Waste: An Ethnographic Study of the Activities Not Only Around the Bulk Container

Hájková, Zuzana January 2015 (has links)
Abctract In my diploma thesis I deal with actions that happen around bulk containers, that are intended to collect larger pieces of domestic waste and that are periodically placed in public space in Prague. I consider the bulk container as an actor, which leads us to particular practices of guarding, disposession and collecting stuff (from the container). I use method of multi-sited ethnography to investigate how the value of disposed objects change according to actions around container and according to change of the context in which it is newly placed. I identify several kinds of value, that are inscribed to wasted objects by their new owners. Waste can become valuable with regard to its economic potencial (as a thing or material that can be sold), with regard to possibility of its further practic use (as a household equipment or material), with regard to its estethic value (as an indicator of taste or as an artefact) or it can gain some specific kind of value in socially engaged context. It is possible to consider the bulk container as an actor of recyclation. I research how various groups of people that are concerned with reusing of waste, interact and how are their interactions, their relationships and their specific practices constitutive for reality of waste in surrounded area of the cotainer and...
8

Circular Economy : Reuse of packaging / Cirkulär Ekonomi : Återanvänding av emballage

Türk, Ferhat, Zandi, Roman January 2019 (has links)
This study is about finding methods for reusing of packaging from Elekta's product "Leksell Gamma Knife ICON" with Circular Economy as the focus. There is no process for this today. The important thing is the analysis of the entire supply chain from Suppliers to customer and then back to Suppliers to get general ideas about what the problems are and then to draw conclusions for the opportunities that exists. The methods used are analyzes if it is cost-effective and environmentally efficient to transport back packaging to the Suppliers who handle these packaging. Costs for the return process have been calculated, which is Supplier work, packaging costs, packaging costs and transport costs. Transport emission in the form of carbon dioxide equivalents have been calculated in the return process. Carbon dioxide equivalents have been calculated for the manufacturing of new packaging and transport by road and ship. The calculated values in the return process are compared with how Elekta is doing today during the process of packing LGK as well as delivering to customers to identify if it is effective to implement a new return process. A solution proposal that fulfils the requirements from an environmental and economic perspective is reported. Environmentally, it is reduced by 459 CO2eq number of carbon dioxide equivalents with transport from the US, 457 CO2eq from China and 1185 CO2eq from Europe. Financially, the company saves 17 190 SEK with transport from the USA, 19327 SEK from China and 18 126 SEK from Europe. / Denna studie handlar att om att hitta metoder för återanvändning av emballagen från Elektasprodukt ”Leksell Gamma Knife ICON” med Cirkulär ekonomi som fokus. Det finns ingen process för detta i dagsläget. Den viktiga är analysen av hela försörjningskedjan från leverantör till kund och sedan tillbaka till leverantörer för att få generella uppfattningar om vad problemen befinner sig och där ifrån dra slutsatser för möjligheterna som finns. De metoder som används är analyser om det är kostnads- och miljöeffektivt att transportera tillbaka emballage till de leverantörer som hanterar dessa emballage. Kostnader för returprocessen har beräknats vilket är leverantörsarbete, emballagekostnader, arbetskostnader och transportkostnader. Transportutsläpp i form av koldioxidekvivalenter har beräknats i returprocessen. Koldioxidekvivalenter har beräknats för tillverkning av nya emballage samt transport med lastbil och fartyg. De beräknade värden i returprocessen jämförs med hur Elekta gör idag under processen att packa LGK samt leverera till kund för att identifiera om det är effektivt att implementera en ny returprocess. Ett lösningsförslag där kraven uppfylls ur ett miljömässigt och ekonomisk perspektiv redovisas. Miljömässigt minskas det med 459 CO2eq antal koldioxidekvivalenter med transport från USA, 457 CO2eq från Kina och 1185 CO2eq från Europa. Ekonomiskt sparar företaget på 17 190 SEK med transport från USA, 19327 SEK från Kina och 18 126 SEK från Europa.
9

Potentials, Enablers and Barriers of a Circular Production System in a Lean Manufacturing Context : A Case Study at Scania

Schmitt, Thomas Konstantin, Wolf, Christopher January 2019 (has links)
Exploitative and profit-oriented business operations are unsustainably depleting the world’s resources and extensively harm the environment. Linear production systems within the manufacturing industry are partly held responsible for this ongoing issue as materials and waste are not getting reused but dumped. An alternative to the traditional linear system that increasingly gets attention in the scientific literature is a Circular Production System within the Circular Economy framework, where waste is treated as resources and streamlined back into the production system to create closed resource loops. However, most manufacturing companies nowadays follow linear production systems and have implemented the Lean philosophy to maximize output and profits, leaving environmental aspects rather behind. This context needs to be considered, when thinking of implementing circular measures within a company. Therefore, this study focused on elaborating potentials, enablers and barriers of a Circular Production System in a Lean context. A case study has been conducted within the Swedish commercial vehicle company Scania, located in Södertälje, to gather empirical data about current lean and already ongoing circular practices in a real-life environment, and on future potential of extending circular measures. Internal benchmark studies, including observational studies and semi-structured interviews have been conducted along Scania’s industrial value chain. External benchmark studies contributed to obtain data about already ongoing CPS initiatives within the manufacturing industry. Following the empirical findings, this study suggests that potentials, enablers and barriers are categorized into system, process and product level, which are interdependent and interrelated. The research revealed that due to the many influences from departments along the value chain on the production, the system as a whole needs to be investigated. This study suggests the 4R framework (reduce, reuse, remanufacture, recycle) for implementing a cascaded use of materials. Implementing a new business model giving the product ownership back to companies would facilitate circular flows in the first place. Such a new business strategy can be supported by following more advanced design strategies, that extend the product life and maintain its performance. Lean, however, was found to bear conflict issues, but is considered still useful to some extent to reduce material inputs through more efficient processes.
10

Avaliação do reaproveitamento de areia de fundição como agregado em misturas asfálticas densas / Evaluation of the reusing of waste foundry sand as an aggregate in dense asphalt

Coutinho Neto, Benedito 16 December 2004 (has links)
A areia de fundição é um resíduo sólido industrial oriundo da etapa de desmoldagem de peças metálicas no processo de produção de fundidos. Esse resíduo, dependendo do processo de fundição utilizado (moldagem a verde, moldagem em casca, moldagem com resina sintética e outros) e do material moldado, pode conter elementos e/ou compostos químicos que podem causar impacto ambiental. As substâncias que podem estar presentes na areia de fundição são provenientes, em parte, do tipo de metal moldado e, em parte, do aglomerante utilizado no processo. O objetivo deste trabalho é apresentar um estudo de alternativa para utilização desse rejeito com a finalidade de contribuir para a minimização do problema, reutilizando-o na composição dos agregados para concreto asfáltico. Para tanto, foram realizados ensaios de classificação de resíduos em amostras de areias virgem e de fundição e em misturas asfálticas, contendo areia virgem e de fundição, não compactadas, para verificar se este resíduo, quando incorporado à massa asfáltica, poluiria o meio ambiente. Realizou-se, também, ensaio de lixiviação com extrator soxhlet em corpo-de-prova de mistura asfáltica com 15% de areia de fundição para avaliar o comportamento, em termos ambientais, desse material a longo prazo. Para verificar o desempenho, da massa asfáltica contendo esse resíduo, na pavimentação, foram realizados ensaios de dosagem Marshall, dano por umidade induzida, cantabro, resistência à tração, módulo de resiliência e fluência estática. Com base nos resultados obtidos, pôde-se concluir, em linhas gerais, que a reutilização de areia de fundição em pavimentação asfáltica é viável, pois as misturas asfálticas contendo esse resíduo apresentaram boas propriedades mecânicas de interesse à pavimentação. Além disso, os ensaios de classificação de resíduos sólidos realizados na massa asfáltica com areia de fundição, cuja classificação original é Classe II - não inerte, ) classificaram a massa asfáltica como resíduo Classe III - inerte, o que sugere um encapsulamento deste resíduo pela massa asfáltica. / Foundry sand is an industrial solid waste resulting from sand casting process in foundry industries. Depending on the type of foundry process (green sand molding, shell sand molding, molding using synthetic resin and others) and of the type cast metal, this waste may contain elements and/or chemical compounds that may cause environmental impact. The substances that may be found in foundry sand proceed partly from the type of the metal and partly from the agglutinant used on the process. The purpose of this research is to present an alternative study for the use of the foundry sand, reusing it in the composition of the aggregate for asphalt concrete and thus to contribute to minimize the environmental impact caused for this waste. To reach this purpose, classification tests of solid wastes were run in virgin sand and foundry sand and asphaltic mixtures not compacted containing both types of sand. This investigation considered the possibility of this waste when incorporated to asphaltic mixture to pollute the environment. Leaching with soxhlet extractor test in specimen of asphaltic mixture with 15% of foundry sand was also realized to evaluate the performance of this material a long-term period in environmental terms. In order to verify the performance in paving, the mixtures were submitted to Marshall method of mix design and to the tests of resilient modulus, indirect tensile strength, cantabro, resistance of compacted bituminous mixture to moisture-induced damage and static creep. Based on the results, it could be concluded that, in a general way, the reuse of foundry sand in asphaltic paving is viable, once the asphaltic mixtures containing this residue presented good mechanical properties. Besides the classification tests of solid wastes realized in asphaltic mixture containing foundry sand, which original classification as class II - no inert, passed to a classification of asphaltic mixture class III - inerte, what suggests that the waste was encapsulated in hot mix asphalt.

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