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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.
271

Beitrag zur simulationsgestützten Planung von Demontagefabriken für Elektro- und Elektronikaltgeräte

Ciupek, Markus. Unknown Date (has links) (PDF)
Techn. Universiẗat, Diss., 2004--Berlin.
272

Entwicklung eines Verwertungsprozesses für niedrig magnesiummetallhaltige Reststoffe /

Niederle, Alf. January 2006 (has links)
Techn. Hochsch., Diss., 2005--Aachen.
273

The Chemical Mechanism of a Brown-Rot Decay Mimtic System and its Application in Paper Recycling Processes

Qian, Yuhui January 2001 (has links) (PDF)
No description available.
274

Ochre and biochar : technologies for phosphorus capture and re-use

Shepherd, Jessica Grace January 2017 (has links)
Despite recent instability in the global supply of phosphate-rock derived fertiliser and the potential for this to continue into the future, the recovery of phosphorus (P) from wastewater treatment systems, where P is abundant and accessible, is well below maximum potential. Considerable resource is spent on removing P from wastewater in order to comply with environmental standards and to protect aquatic ecosystems from eutrophication, yet there is little emphasis on capturing the P in a way that is optimised for re-using it as agricultural fertiliser. To address this lack of innovation in the face of climate change and food insecurity, a concept for a material capable of capturing P from wastewater was developed, with an emphasis on the utilisation of otherwise waste materials and the use of carbon neutral or negative production technologies. Based on the demonstrated P capture properties of coal minewater treatment waste (ochre) and biochar made from anaerobically digested feedstocks, a range of biochars were designed and produced using different mixtures of ochre (“OC”), sourced from the UK Coal Authority Minto minewater treatment scheme in Fife, Scotland and anaerobically digested sewage sludge (“AD”), sourced from the Newbridge wastewater treatment plant in Edinburgh. A first generation of materials consisting of either AD or a 1:1 mixture (dry weight basis) of OC and AD were produced in a small-scale batch pyrolysis unit at two pyrolysis highest treatment temperatures (HTTs) (450 and 550°C) to give the biochars AD450, AD550, OCAD450 and OCAD550. These were tested for their P capture properties in repeated P-exposure experiments with pH buffering in comparison to unpyrolysed ochre, activated carbon and a natural zeolite. After 5 days of repeated exposure to a P solution at a wastewater-relevant concentration (20 mg P l-1) replenished every 24 h, relatively high masses of P were recovered by ochre (1.73 ± 8.93×10-3 mg P g-1) and the biochars OCAD550 (1.26 ± 4.66×10-3 mg P g-1), OCAD450 (1.24 ± 2.10×10-3 mg P g-1), AD450 (1.06 ± 3.84×10-3 mg P g-1), and AD550 (0.986 ± 9.31×10-3 mg P g-1). The biochar materials had higher removal rates than both activated carbon (0.884 ± 1.69×10-2 mg P g-1) and zeolite (0.130 ± 1.05×10-2 mg P g-1). To assess the extractability of recovered P and thus potential plant bioavailability, P exposure was followed by repeated extraction of the materials for 4 days with pH 7-buffered deionised water. The AD biochars retained 55% of the P recovered, OCAD biochars 78% and ochre 100%. Assessment of potentially toxic element (PTE) concentrations in the biochars against guideline values indicated low risk associated with their use in the environment. A second generation of materials were produced to examine the scalability of the concept. Mixtures of AD and OC were pelletised with a lignin binder (89.1:9.9:1.0 ratio, dry weight basis) and AD was pelletised with binder (99:1 ratio, dry weight basis). The pelletised feedstocks were pyrolysed in a bench-scale continuous flow pyrolysis kiln at the same two HTTs to give the pelletised biochars PAD450, PAD550, POCAD450 and POCAD550. Analysis of digested biochar samples compared to the previous generation of biochars showed general similarities between the two groups, apart from the substantially lower Fe content. Sub-samples of the pelletised biochars were exposed to a 20 mg l-1 P solution over 6 days, with the solution replaced every 24 h to give the P-exposed biochars EPAD450, EPAD550, EPOCAD450 and EPOCAD550. To probe the mechanisms of P capture by these materials and how feedstock preparation and pyrolysis conditions affected these, spectroscopic analysis using laser-ablation (LA) ICP-MS, X-ray diffraction, X-ray photo-electron spectroscopy (XPS) and scanning electron microscopy coupled with energy dispersive X-ray was performed. The results highlighted the general importance of Fe minerals in P capture and subsidiary roles for Al, Ca and Si. A 3-week barley (Hordeum vulgare) seedling growth experiment was conducted using the pelletised and P-exposed biochars, in comparison with other biochars produced using feedstock which contained high amounts of PTEs. The biochars were also extracted using a range of different methods used to assess the bioavailability of PTEs and nutrients in soils, and the results compared to digests of barley leaves to identify whether any of these could reliably predict plant bioavailability in biochar. The above ground biomass and its total P concentration of barley grown in a 5% mixture of EPOCAD550 in sand was significantly higher than the control (p < 0.05 and p < 0.01, respectively). A significant positive correlation between mean leaf P mass and dry weight leaf yield (R2 = 0.865, p < 0.001) was found, indicating that dry weight yield could be used as an indicator for the P fertilising capability of biochar for barley seedlings. Element concentrations in unbuffered and buffered and (pH 7) 0.01 M CaCl2 biochar extractions were significantly positively correlated with plant leaf concentration for 6 of the 18 elements investigated, more than any of the other extractions. A longer barley growth experiment was conducted, using rhizoboxes, to test the bioavailability of P in the biochars compared to conventional fertiliser. The pelletised and Pexposed biochars were applied to a sandy loam soil with P constraints. Biochar application rates were based on 2% formic acid extractable P, calculated for summer barley using Index 0 soil. Analysis of total leaf length at harvest (12 weeks), dry weight yield, leaf P concentration and leaf P mass showed no significant differences between the biochar treatments, NPK fertilised and NK fertilised controls. This shows that biochar, when applied at low total application rates based on extractable P, is as effective as conventional fertiliser. Now that AD biochar materials have been shown to have useful phosphorus recycling properties in laboratory experiments, additional work is required to optimise their use in wastewater and agricultural systems. The next stage of research should determine their performance in flow-through filtration systems with simulated and real wastewater effluent, as well as their performance in field trials with different crops of interest to demonstrate their potential as viable alternative fertilisers.
275

Trabalhadores na reciclagem do lixo : dinâmicas econômicas, sócio-ambientais e políticas na perspectiva de empoderamento

Martins, Clitia Helena Backx January 2003 (has links)
Esta pesquisa enfoca as dinâmicas econômicas, sócio-ambientais e políticas de organização, construção da identidade coletiva e empoderamento de trabalhadores em associações de reciclagem, levando-se em conta suas relações com diversos agentes externos. A escolha desse objeto do estudo prende-se a dois aspectos principais: - à caracterização dessa atividade como uma ocupação em estruturação e processo de reconhecimento, representando uma possibilidade de sustentabilidade e autonomia para setores da população de baixa renda em países em desenvolvimento; - a uma situação peculiar de relação entre Estado e sociedade, na qual as associações de catadores/recicladores interagem simultaneamente com órgãos dos governos municipais respectivos, do governo estadual e com entidades não-governamentais, como setores da Igreja Católica e ONGs nacionais e internacionais. Através da análise comparativa das características de três associações de reciclagem na Região Metropolitana de Porto Alegre, verificam-se resultados diferenciados no que diz respeito a processos internos de organização do trabalho e de participação nas decisões, bem como em relação às percepções, motivações e expectativas dos catadores/recicladores quanto a sua ocupação. / This research focuses on the economic, socio-environmental and political dynamics related to organization, construction of collective identity and empowerment of workers in recycling cooperatives, taking into account their relationships with several external agents. The choice of this object relies on two main aspects: - the characterization of this activity as an occupation being structured and recognized, representing a possibility of sustainability and autonomy for sectors of low income people in developing countries; - a peculiar kind of State-civil society relation, in which recycling cooperatives interact simultaneously with local and regional public entities, and non-governmental organizations, like catholic institutions or other NGOs. Through a comparative analysis of characteristics of three recycling cooperatives in Porto Alegre Metropolitan Region, distinct results were found, concerning internal processes of work organization and decision-making participation, as well as the perceptions, motivations and expectations of the recycling workers towards their occupation.
276

CAMPUS RECYCLING - INFLUENCES AND DECISIONS

Lopeman, Brooke Ann 01 May 2014 (has links)
AN ABSTRACT OF THE THESIS OF BROOKE A LOPEMAN, for the Master of Science degree IN GEOGRAPHY AND ENVIRONMENTAL RESOURCES, presented on JULY 6, 2011, at Southern Illinois University Carbondale. TITLE: CAMPUS RECYCLING - INFLUENCES AND DECISIONS MAJOR PROFESSOR: Dr. Matthew Therrell The purpose of this study is to assess the factors that most influence decision making in regards to environmental programming on a university campus. The results of this study serve as a guide for campus administration when implementing future environmental programs. At most universities there is a large population living on campus, this creates the opportunity to encourage pro-environmental attitudes and behaviors of a large population. College, for many students, is the first time away from their family home and a time they can develop new attitudes and behaviors. This allows campus administrators the opportunity to influence students at a time in which they are developing new habits. It is important for campus administration to understand the factors that influence students' participation in environmental programs and how to influence students' long term attitudes and behaviors toward environmental concerns. This study determined which factors most strongly influence students to participate in the recycling program within their residence halls. The roles and attitudes of University Housing Staff toward current environmental programs were also assessed. Improved understanding of student participation and administrator roles can help support future environmental efforts on campus. Interviews with administrators showed that while administration may have a reasonable understanding of the factors that influence students to participate in recycling programs; this understanding does not extend to the actual programs that are being implemented. Of the students surveyed in this research, 100% responded that they thought there are improvements that should be made to increase recycling on campus. The factors that should most influence administrators in environmental decisions on campus were explored with student opinions of the current programs. The recycling research completed shows that both convenience and pro-environmental education are important influences on students' decisions to participate in recycling programs within their residence halls. The research shows that recycling increased by 50% with the addition of both convenience and pro-environmental education. Based on the increase in the amount of recycling per person in this study, the addition of these two components throughout the residence halls at Southern Illinois University could result in approximately 3,750 pounds of waste reduction per semester. While convenience has been shown to have an influence on recycling, e.g. Jennings (2004), this study focuses on the influence of pro-environmental education as well. Education is an important component that many environmental programs on campus are lacking.
277

Representações sociais e práticas cotidianas de trabalhadores e trabalhadoras do lixo - a experiência do centro comunitário Santa Terezinha / Social representations and daily practical of workers of the garbage - the experience of the Santa Terezinha Communitarian Center

Carvalho, Everjane de January 2004 (has links)
CARVALHO, Everjane de. Representações sociais e práticas cotidianas de trabalhadores e trabalhadoras do lixo - a experiência do centro comunitário Santa Terezinha. 2004. 84 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Mestrado em Desenvolvimento e Meio Ambiente, Fortaleza-CE, 2004. / Submitted by demia Maia (demiamlm@gmail.com) on 2016-05-13T14:02:47Z No. of bitstreams: 1 2004_dis_ecarvalho.pdf: 325080 bytes, checksum: 085476bac044ae68f1643004e4d48407 (MD5) / Approved for entry into archive by demia Maia (demiamlm@gmail.com) on 2016-05-13T14:03:41Z (GMT) No. of bitstreams: 1 2004_dis_ecarvalho.pdf: 325080 bytes, checksum: 085476bac044ae68f1643004e4d48407 (MD5) / Made available in DSpace on 2016-05-13T14:03:41Z (GMT). No. of bitstreams: 1 2004_dis_ecarvalho.pdf: 325080 bytes, checksum: 085476bac044ae68f1643004e4d48407 (MD5) Previous issue date: 2004 / O presente trabalho busca apreender as representações sociais de trabalhadores e trabalhadoras do lixo e suas práticas cotidianas, a partir da experiência do Centro Comunitário Santa Terezinha, com o Programa Reciclando - Rede Solidária de Coleta Seletiva. Parte-se do pressuposto de que as representações sociais se constroem no cotidiano e orientam as ações das pessoas. Nesse processo de interação entre a ação e as reflexões, as representações sociais modificam as práticas sociais e são modificadas pelas mesmas. Na reflexão acerca do trabalho realizado pelos agentes analisa-se a forma de ocupação espacial que se deu no morro Santa Terezinha bem como os novos sentidos atribuído às vias públicas como locus de trabalho e não como via de acesso que se dá nos bairros nobres ao redor do Morro. A pesquisa foi realizada com agentes recicladores do referido Centro. Os agentes buscam resignificar seu trabalho atribuindo um conjunto de regras que os diferenciam dos outros profissionais que se ocupam da mesma atividade na área da pesquisa. Dessa forma estes procuram superar os preconceitos existentes em relação à atividade da coleta. Observa-se que a coleta seletiva não se dá em virtude da ausência de um investimento em educação ambiental que possibilitaria a separação do lixo na própria fonte geradora. Os poucos clientes que separam é resultado da iniciativa pontual dos agentes que negociam em alguns condomínios essa separação. O cotidiano dos agentes consiste em percorrer as ruas e remexendo o lixo deixado nas calçadas recolher o material reciclável para posterior venda dos mesmos. Transitar nas ruas competindo com os carros representa um risco para os agentes. Outro risco a que estão submetidos é o de adquirir doenças em decorrência do contato direto com materiais contaminados. A falta de seguranças trabalhistas preocupa os agentes. Acredita-se que se impostos são pagos para assegurar a limpeza urbana esse trabalho deveria ser subsidiado pelo poder público de forma a garantir uma melhor condição de vida e trabalho aos agentes. Os problemas ambientais apontam para a urgência de um desenvolvimento sustentável para a sociedade. Educação ambiental e coleta seletiva do lixo são instrumentos fundamentais na luta pela sustentabilidade.
278

Powder Recycling for the Production of Pin Fin Heat Sinks by Cold Gas Dynamic Spray

Perry, Justin 05 November 2018 (has links)
As a result of the rise in processing power demands of today’s personal computers, water cooled pin fin heat sinks are increasingly being employed for the cooling of graphical processing units. Currently, these high performance devices are manufactured through high-cost, high-waste processes. In recent years, a new solution has emerged using the cold gas dynamic spray process, in which pin fins are directly manufactured onto a baseplate by spraying metallic powder particles through a mask. This process allows for a high degree of adaptability to different graphics processing unit shapes and sizes not achievable by any other process to date. One drawback of this process is that, as substrate sensitivity to heat and mechanical residual stresses requires the use of reduced spray parameters, there is reduced deposition efficiency, resulting in a fair portion of the feedstock powder being wasted. This work aims to demonstrate the feasibility of using powder recycling to mitigate this issue and compares coatings sprayed with reclaimed powder to their counterparts sprayed with as-received powder. The work demonstrates that cold gas dynamic spray is a highly flexible and economically competitive process for the production of pin fin heat sinks when using powder recycling even when spray parameters result in reduced deposition efficiency. The benefits of pin fins on heat transfer properties of flat plates used for graphical processing units is briefly addressed and demonstrated
279

A social dilemma perspective on socially responsible consumption

Lee, Ada Lai Yung 29 August 2016 (has links)
Recent research on corporate social responsibility has focused on the corporate level, whereas limited research has been conducted at the individual level most commonly referred to as socially responsible consumption. Recycling is a kind of socially responsible consumer behaviour because it benefits the society as a whole in the long term but involves a personal cost and does not benefit the individual consumer directly. Previous studies on recycling have used theories such as the theory of interpersonal behaviour, means-end chain theory, theory of planned behaviour or norm activation model. However, these theories have only explained part of recycling behaviour and are inadequate because they have not explained it from a social dilemma perspective. A social dilemma is a situation in which there is conflict between an individual's self-interest and the collective interest of the group. Will consumers pursue their own interests or will they act for the good of the entire society? This study takes an innovative approach to explain recycling behaviour through the lens of social dilemma theory. It uses a mixed methods approach that combines both qualitative and quantitative elements in the research design. A phenomenological approach is used to gain a deeper understanding of the recycling experiences of individuals, and survey data is used for quantitative analyses. In the qualitative study, 142 significant statements and eight themes were identified from 20 in-depth interviews. In the quantitative study, data were collected from 332 respondents. Based on the data analysis, the central relationships in the model are supported. There is a positive relationship between the expectation that others will participate in recycling and the likelihood of personal participation in recycling, and there is also a positive relationship between the likelihood of personal participation and recycling behaviour. Of the four moderators considered, only social value orientation is significant. In the latter part of this thesis, the theoretical and methodological contributions and practical implications of the study are discussed.
280

Sustainability and recycling in fifteenth-century manuscripts

Ryley, Hannah January 2016 (has links)
This thesis examines the sustainability of fifteenth-century manuscripts. It analyses the durability of manuscripts, and the ways in which people recycled and reused their books. During the long fifteenth-century (here, 1375-1530), book production in England flourished, driven by increased demand for books. Yet while the fast-developing commercial book trade produced new books in great quantity, significantly, older books were also sustained, recycled and reused. Although there is awareness within medieval scholarship of recycled manuscript components, such as flyleaves, no sustained study has yet been undertaken into recycled and reused materials in fifteenth-century manuscripts, or into book production's practices and processes of reuse. In addition, previous book history studies of recycling have focused on the book material reuse that followed the Dissolution. By contrast, this study offers a broader exploration of sustainable practices in fifteenth-century manuscript culture, as well as in-depth analysis of manuscript examples, to argue that book producers made and reused books in sustainable ways. The introduction outlines key concepts and relevant scholarship, such as studies that follow the material turn, and ecocriticism. The four chapters that follow address sustainability from different angles, focusing primarily on the evidence both in and written on books themselves. Chapter 1 explores the craftsmanship of parchment- making through contemporary recipes and physical evidence in manuscripts. Chapter 2 presents case studies of parchment reused sustainably in books, as off-cuts, quire guards, flyleaves, pastedowns, limp covers, and palimpsests. Chapter 3 surveys spaces reclaimed in books for opportunistic mark-making, in the form of doodles, jottings, and short verses. Chapter 4 presents three surveys of second-hand books and the inscriptions written onto their leaves. A conclusion draws together the findings. This thesis augments and nuances current scholarship by arguing that fifteenth-century reuse and recycling of book materials were customary aspects of book production and symptomatic of more widespread sustainability in manuscript culture.

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