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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

Extended producer responsibility as a management practice for waste mattresses in British Columbia

Hume, Miles Grey 12 March 2014 (has links)
Development of stewardship programs for management of end-of-life mattresses (ELM) is a global challenge for governments. Metro Vancouver is the first Canadian regional government to ban mattresses at local landfills. The next step is for manufacturers and retailers to work with local governments in developing stewardship programs that successfully divert and recycle mattresses across British Columbia (BC). This thesis examines how mattress industry stakeholders in BC could effectively implement province wide mattress stewardship policy that will ensure maximum public participation and will be environmentally sound as well as cost effective. Research was conducted by way of a literature review, a case study approach of Metro Vancouver's mattress recycling bylaw and model, and exploratory interviews with BC stewardship program leaders, Sleep Country Canada, government waste management planners, and mattress recyclers.
2

Utvecklingav Lindevalls skyddsmadrasser

Essén, Nils, Rönnblad, Jonas January 2017 (has links)
På uppdrag av Lindevalls i Östersund har material till skyddsmadrasserstuderats och undersökts för att ta reda på hur förbättringar kan göras. Syftetmed studien har varit att identifiera material och materiella strukturer attanvända i skyddsmadrasserna. Målet med projektet har varit att hitta en bättrelösning än vad som används i dagens skyddsmadrasser med hjälp av tester,materialstudier och lämplig teori. Den slutgiltiga lösningen skall, precis somdagens, inneslutas med en PVC-väv och kräver minst lika bra kraftupptagningsförmåga.Tester kopplat till projektet, har varit avgränsade till endast småskaligaprototyper för att vara anpassad till tillhandahållen testutrustning. Projektethar genomförts i sex olika etapper, förstudie, produktspecificering,prototypgenerering och tester, prototyputvärdering och val samtdetaljkonstruktion och konfigurering. Förstudien och produktspecificeringen gavinformation hur marknaden förhåller sig och vad som skulle genomföras.Prototypgenereringen har drivits framåt med hjälp av prototypdrivenproduktutveckling med stöd från kravspecifikation. Med kontinuerlig utvärderingmed beställare och tester, har etappen “loopats” efter uppdatering av kravspecifikation.En slutgiltig prototyp identifierades efter att den uppfyllt krav och önskemåli etappen prototyputvärdering och val, för att sedan tas vidare tilldetaljkonstruktion. P.g.a. för hög produktionstid skapades en skärmall för atteffektivisera produktion av prototyp, i syfte att minska produktionskostnaden.Slutsatsen av projektet är att projektets syfte och mål har granskats med hjälpav tester och undersökningar. Dock har målet som var att finna en bättre lösning,inte uppfyllts då dagens lösning anses bättre. / On behalf of Lindevalls in Östersund materials forprotective mattresses have been studied and investigated to find out howimprovements can be done. The purpose of the study has been to identifymaterials and material structures for use in the protection mattresses. Thegoal of the project was to find a better solution than what’s used in currentprotective mattresses through using tests, material studies and theory. Thefinal solution, like today's, will be enclosed with a PVC fabric and requiresat least as good power absorption capacity. Tests linked to the project havebeen limited to small-scale prototypes to be adapted to accessed testequipment. The project has been carried out in six stages, preliminary studies,product specification, prototype production and testing, prototype evaluationand selection, detailed design and configuration. The pilot study and productspecification provided information on how the market relates and what should beperformed. Prototype production has been driven forward by using theprototype-driven product development with the support of the requirementspecification. With continuous evaluation with clients and tests, the stage hasbeen "looped" after updating requirement specification. A finalprototype was identified after meeting key requirements and requests in thestage selection, to proceed to detail construction. Because to high productiontime a cutting template was created to streamline prototype production, inorder to reduce production costs. The conclusion of the project is that the project'spurpose and goal have been examined by means of tests and surveys. However, thegoal of finding a better solution has not been met because the solution usedtoday is considered better. / <p>År och termin: 2017 VT</p><p>Datum för betyg: 2017-09-18</p>
3

Studies on particle resuspension, infant exposure, and the sleep microenvironment

Boor, Brandon Emil 17 September 2015 (has links)
Understanding the transport of particulate and gaseous indoor air pollutants from source to exposure is paramount to improve our understanding of the complexities of the built environments in which we spend the majority of our time. This dissertation offers new insights on particle resuspension from indoor surfaces, infant exposure to organic contaminants released from crib mattresses, and the dynamics of pollutant transport and human exposure while sleeping. Particle resuspension is the physical process by which settled particles detach from a surface and become airborne through application of various aerodynamic and mechanical removal forces. Resuspension is an important indoor source of coarse mode particles (> 1 µm in diameter) and can be a source mechanism for biological matter and organic contaminants that accumulate in house dust. Settled dust deposits on indoor surfaces can vary considerably in their structure and mass loading, yet little is known as to how these parameters affect resuspension. Through wind tunnel experiments, this research demonstrates that the deposit structure (monolayer or multilayer) can have a significant impact on the number of particles that aerodynamically resuspend. Furthermore, this dissertation presents the first full-scale experimental chamber study to show that human body movements in bed can resuspend settled mattress dust particles. An indoor aerosol model was utilized to provide a mechanistic understanding of the impact of movement intensity, surface vibrations, bedroom ventilation rate, and dust loading on the resuspension flux and intake fraction of resuspended particles. Infants spend most of their time sleeping and are likely to be exposed to elevated concentrations of chemicals released from their crib mattresses. Through a combination of chamber experiments and solvent extractions, this research shows that infant crib mattresses can emit a variety of volatile organic compounds (VOCs) and contain numerous chemical additives, including phthalate and alternative plasticizers, flame retardants, and unreacted isocyanates. Additionally, this study discovered that infants are exposed to approximately twice the concentrations of VOCs in their breathing zones as compared to the bulk bedroom air, due to their close proximity to the source.
4

Long Walk in Flight School

May, William H., IV 01 January 2005 (has links)
Long Walk in Flight School is a document intended to complement a body of artwork that includes photographs, giclee prints, animation, and a twenty two page book of images. The main focus of the text is to discuss two types of exchange; my energy with tools in exchange for an object or event, which is then exchanged in the imagination of the audience for something else, a hybrid thing. These exchanges are part of the performance or presentation of the work. Beginning with a brief description of intent at the start of graduate school, it traces my development as an artist over a two year period, highlighting shifts in my thinking and activity during that time. Finally, it describes my thesis artwork as a set of potential narratives that are conceptually related but visually diverse.
5

Discos sustentados por colchão de ar: uma nova proposta. / Air-supported pucks: a new proposal.

Hessel, Roberto 27 November 1981 (has links)
Os discos sustentados por colchão de ar têm encontrado larga aplicação didática. Sua utilização, contudo, esbarra em algumas dificuldades, pois os sistemas convencionais que permitem registrar as trajetórias dos discos e fornecer o gás para sustentá-los tornam difícil e dispendioso o seu emprego. Neste trabalho mostra-se como essas dificuldades podem ser superadas, utilizando idéias diferentes daquelas que vêm sendo seguidas tradicionalmente. Três novos discos sustentados por colchão de ar são estudados. Um deles leva um reservatório de ar consigo e dispõe de um circuito eletrônico acoplado a um sistema eletromecânico que permite registrar fácil e economicamente a trajetória do disco. Os outros dois dispõem de uma bomba de ar solidária a eles e de um sistema eletromecânico semelhante ao do primeiro modelo. Experiências realizadas com as três versões construídas são também apresentadas e analisadas. / There are many applications of air-suspended pucks in physics teaching. However, there are some difficulties in their widespread utilization, particularly in their maintenance and handling, because of the high cost of the conventional systems of recording the trajectories and supplying the gas needed to support the pucks. In this paper we present some new ideas to overcome these difficulties. Three new air-suspended pucks are studied. One of them carries its own supply or air and is equipped with an electronic circuit coupled to an electromechanical system that provides an easy and inexpensive way to record its trajectory. The other two have an air pump fastened to them and use electromechanical system similar to that of the first model. Experiments performed with the three versions that have been constructed are also presented and analyzed.
6

Desenvolvimento de misturas tern?rias para remo??o de reboco de fluido de perfura??o sint?tico

Pinheiro, Francisca Sheldakelle Holanda Torres 01 April 2013 (has links)
Made available in DSpace on 2014-12-17T15:42:26Z (GMT). No. of bitstreams: 1 FranciscaSHTP_TESE.pdf: 2918129 bytes, checksum: e712b711537d456c1dd4eaa0f003f3af (MD5) Previous issue date: 2013-04-01 / The construction of wells is one of the most important activities of the oil industry. The drilling process is the set of activities and operations to design, program and perform the opening thereof. During this process, the cuttings are removed by the drilling fluid, or mud, and carted to the surface. This fluid is injected into the drill string and returns to the surface through the annular space between the well walls and the drill string. After the descent of the column casing, the annular space between the casing string and the walls of the borehole is filled with cement so as to secure the spine and prevent any migration of fluids between the various permeable zones traversed by the well behind of the coating. To ensure the good quality of the cementation scrubbers are used mattresses which are pumped ahead of the cement slurry so as to avoid contamination of the drilling fluid paste, or vice versa, and assist in the removal of plaster, formed by drilling fluid of the borehole walls, thus enabling a better cement bond to the well. Within this context, this work aims to evaluate the efficiency of mattresses scrubbers, the basis of ionic and nonionic surfactants, on the removal of nonaqueous drilling fluid, based on n-paraffin in oil wells, and the compatibility between the Mattress relations washer / drilling fluid bed scrubber / cement paste mattress washer / cement slurry / drilling fluid and the drilling fluid / cement slurry using laboratory tests rheology, thickening time and compressive strength. Also technique was performed X-ray diffraction (XRD) for a more detailed analysis of these mixtures with hydrated cement paste. In compatibility tests the conditions of temperature and pressure used in the same laboratory procedure simulating the conditions of oil wells, the well is considered the depth of 800 m. The results showed that the compositions of the mattress washer nonionic, KMS obtained a 100% efficient in removing the non-aqueous drilling fluid, and the best formulation showed good results with respect to compliance testing / A constru??o de po?os ? uma das atividades mais importantes da ind?stria do petr?leo. O processo de perfura??o de po?os ? o conjunto de atividades e opera??es destinadas a projetar, programar e realizar a abertura dos mesmos. Durante este processo, os cascalhos s?o removidos pelo fluido de perfura??o, ou lama, e carreados at? a superf?cie. Este fluido ? injetado no interior da coluna de perfura??o e retorna ? superf?cie atrav?s do espa?o anular entre as paredes do po?o e a coluna de perfura??o. Ap?s a descida da coluna de revestimento, o espa?o anular entre a coluna de revestimento e as paredes do po?o ? preenchido com cimento, de modo a fixar a coluna e evitar que haja migra??o de fluidos entre as diversas zonas perme?veis atravessadas pelo po?o, por tr?s do revestimento. Para garantir a boa qualidade da cimenta??o, s?o utilizados os colch?es lavadores, que s?o bombeados ? frente da pasta de cimento, de modo a evitar a contamina??o da pasta pelo fluido de perfura??o, ou vice-versa, al?m de auxiliar na remo??o do reboco, formado pelo fluido de perfura??o, das paredes do po?o, possibilitando assim uma melhor ader?ncia do cimento ao po?o. Dentro deste contexto, este trabalho tem como objetivo avaliar a efici?ncia de colch?es lavadores, a base de tensoativos i?nico e n?o i?nico, na remo??o do fluido de perfura??o n?o aquoso, ? base de n-parafina, em po?os de petr?leo, e a compatibilidade entre as rela??es colch?o lavador/fluido de perfura??o, colch?o lavador /pasta de cimento, colch?o lavador /pasta de cimento/fluido de perfura??o e fluido de perfura??o/pasta de cimento utilizando os ensaios laboratoriais de reologia, tempo de espessamento e resist?ncia ? compress?o. Tamb?m foi realizada a t?cnica difra??o de raios X (DRX) para uma an?lise mais detalhada dessas misturas com a pasta hidratada de cimento. Nos ensaios de compatibilidade as condi??es de temperatura e press?o utilizadas nos procedimentos laboratoriais simularam as mesmas condi??es dos po?os de petr?leo, sendo a profundidade do po?o considerada de 800 m. Os resultados mostraram que as composi??es do colch?o lavador n?o i?nico, o KMS, obtiveram uma efici?ncia de 100% na remo??o do fluido de perfura??o n?o aquoso e a sua melhor formula??o apresentou resultados satisfat?rios em rela??o aos testes de compatibilidade
7

Investigation of methods used to predict the heat release rate and enclosure temperatures during mattress fires

Threlfall, Todd 05 September 2005
Fires in buildings ranging in size from small residential houses to large office buildings and sports stadiums pose significant threats to human safety. Many advances have been made in the area of fire behaviour modeling and have lead to much safer, and more efficient fire protection engineering designs, saving countless lives. Fire, however, is still a difficult phenomenon to accurately model and the most important quantity used to describe a fire is the heat (energy) release rate (HRR). Predictions of the fire hazard posed by mattresses, using relatively simple modeling techniques, were investigated in this research work and compared to full-scale experimental results. Specifically, several common methods of predicting the HRR from a mattress fire were examined. Current spatial separation guidelines, which exist in order to mitigate fire spread between buildings, were used to predict radiation heat flux levels emitted by a burning building and compared to experimental results measured in the field. Enclosure ceiling temperatures, predicted using the Alpert temperature correlation, and average hot gas layer temperature predictions were also compared to experimental results. Results from this work indicate that the t-squared fire heat release rate modeling technique combined with the common Alpert ceiling temperature correlation, provide a reasonable prediction of real-life fire temperatures as results within 30% were obtained. The cone calorimeter was also found to be a useful tool in the prediction of full-scale fire behaviour and the guidelines used for spatial separation calculations were found to predict the radiant heat flux emitted by a burning building reasonably well.
8

Investigation of methods used to predict the heat release rate and enclosure temperatures during mattress fires

Threlfall, Todd 05 September 2005 (has links)
Fires in buildings ranging in size from small residential houses to large office buildings and sports stadiums pose significant threats to human safety. Many advances have been made in the area of fire behaviour modeling and have lead to much safer, and more efficient fire protection engineering designs, saving countless lives. Fire, however, is still a difficult phenomenon to accurately model and the most important quantity used to describe a fire is the heat (energy) release rate (HRR). Predictions of the fire hazard posed by mattresses, using relatively simple modeling techniques, were investigated in this research work and compared to full-scale experimental results. Specifically, several common methods of predicting the HRR from a mattress fire were examined. Current spatial separation guidelines, which exist in order to mitigate fire spread between buildings, were used to predict radiation heat flux levels emitted by a burning building and compared to experimental results measured in the field. Enclosure ceiling temperatures, predicted using the Alpert temperature correlation, and average hot gas layer temperature predictions were also compared to experimental results. Results from this work indicate that the t-squared fire heat release rate modeling technique combined with the common Alpert ceiling temperature correlation, provide a reasonable prediction of real-life fire temperatures as results within 30% were obtained. The cone calorimeter was also found to be a useful tool in the prediction of full-scale fire behaviour and the guidelines used for spatial separation calculations were found to predict the radiant heat flux emitted by a burning building reasonably well.
9

Painéis de partículas orientadas (OSB) da madeira de Pinus spp. e Eucalyptus benthamii / Oriented strand board (OSB) with wood of Pinus spp. and Eucalyptus benthamii

Gorski, Luciane 08 May 2014 (has links)
Made available in DSpace on 2016-12-12T20:12:29Z (GMT). No. of bitstreams: 1 PGEF14MA009.pdf: 1650293 bytes, checksum: 26d8474802a33a6caccdc7baa3aa2780 (MD5) Previous issue date: 2014-05-08 / The objective was to produce and evaluate oriented strand board (OSB) of Eucalyptus benthamii Maiden et Cambage and Pinus spp. by the physical and mechanical properties. The particles of Eucalyptus were obtained from logs reforestation with 13 years old already particles of Pinus spp. came from industrial process, being composed of the mix of particles of Pinus taeda and Pinus elliottii. The proportions of face:core:face adopted were 20:60:20 and 30:40:30, where the mattress particles was composed of 3 layers arranged perpendicular to each other. The experimental plan involved 10 treatments with 3 repetitions, where we compared Eucalyptus, Pinus, and panels with layers of different species and panels with mixed particles of both species. The panels were produced with a density of 0.65 g/cm3, 6% phenol formaldehyde resin, 1% paraffin emulsion and pressing cycle with 180°C, 40 kgf/cm2 for 8 minutes. The assays were performed according to ASTM D1037 (1993) and DIN 52362 (1982). In statistics analysis was applied to analysis of variance and the Scott- Knott test at 95% probability, beyond comparison with those of the standard CSA 0437 (1993). The results showed that panels composed solely of Eucalyptus showed the best results for water absorption, thickness swelling and spring back, but the results were not satisfactory when compared with the reference standard. For mechanical properties, in general, the best results were obtained in the treatment of particles composed solely of Pinus. Some treatments have not reached the minimum required by the standard for the testing of MOE and MOR, and besides, the greatest results for the parallel direction were obtained in the ratio 30:40:30 and perpendicular to the ratio 20:60:20 were found. As for internal bond, all treatments reached the minimum values of the two ratings. Thus, the results of this study indicate that E. benthamii can be an alternative for the production of oriented strand board (OSB) / O objetivo foi produzir e avaliar painéis de partículas orientadas (OSB) de Eucalyptus benthamii Maiden et Cambage e Pinus spp. por meio das propriedades físicas e mecânicas. As partículas de Eucalyptus foram obtidas a partir de toras de reflorestamentos com 13 anos de idade, já as partículas de Pinus spp. foram provenientes de processo industrial, sendo composto pelo mix de partículas de Pinus taeda e Pinus elliottii. As proporções face:miolo:face adotadas foram 20:60:20 e 30:40:30, onde o colchão de partículas foi composto por 3 camadas dispostas perpendicularmente entre si. O delineamento experimental envolveu 10 tratamentos, com 3 repetições cada, onde comparou-se painéis de Eucalyptus, painéis de Pinus, com camadas de espécies distintas e painéis com partículas de ambas as espécies misturadas. Os painéis foram produzidos com densidade de 0,65 g/cm3, 6% de resina fenol-formaldeído, 1% de emulsão de parafina e ciclo de prensagem de 180ºC, 40 kgf/cm2 por 8 minutos. Os ensaios foram realizados de acordo com a ASTM D1037 (1993) e a DIN 52362 (1982). Na análise dos resultados foi aplicada a Análise de Variância e Teste de Scott-Knott a 95% de probabilidade, além da comparação com os parâmetros da norma CSA 0437 (1993). Os resultados demonstraram que os painéis compostos exclusivamente por Eucalyptus apresentaram os melhores resultados para absorção de água, inchamento em espessura e taxa de não retorno em espessura, porém os valores não foram satisfatórios quando comparados com a norma de referência. Para propriedades mecânicas, em geral, os melhores resultados foram obtidos no tratamento composto somente por partículas de Pinus. Alguns tratamentos não atingiram o mínimo exigido pela norma para os ensaios de MOE e MOR, além do que, os maiores resultados para o sentido paralelo foram obtidos na proporção 30:40:30 e para o perpendicular foram encontrados na proporção 20:60:20. Já para ligação interna, todos os tratamentos atingiram os valores mínimos das duas classificações. Assim, os resultados deste trabalho indicam que a madeira de E. benthamii pode ser uma alternativa para a produção de painéis de partículas orientadas (OSB)
10

Discos sustentados por colchão de ar: uma nova proposta. / Air-supported pucks: a new proposal.

Roberto Hessel 27 November 1981 (has links)
Os discos sustentados por colchão de ar têm encontrado larga aplicação didática. Sua utilização, contudo, esbarra em algumas dificuldades, pois os sistemas convencionais que permitem registrar as trajetórias dos discos e fornecer o gás para sustentá-los tornam difícil e dispendioso o seu emprego. Neste trabalho mostra-se como essas dificuldades podem ser superadas, utilizando idéias diferentes daquelas que vêm sendo seguidas tradicionalmente. Três novos discos sustentados por colchão de ar são estudados. Um deles leva um reservatório de ar consigo e dispõe de um circuito eletrônico acoplado a um sistema eletromecânico que permite registrar fácil e economicamente a trajetória do disco. Os outros dois dispõem de uma bomba de ar solidária a eles e de um sistema eletromecânico semelhante ao do primeiro modelo. Experiências realizadas com as três versões construídas são também apresentadas e analisadas. / There are many applications of air-suspended pucks in physics teaching. However, there are some difficulties in their widespread utilization, particularly in their maintenance and handling, because of the high cost of the conventional systems of recording the trajectories and supplying the gas needed to support the pucks. In this paper we present some new ideas to overcome these difficulties. Three new air-suspended pucks are studied. One of them carries its own supply or air and is equipped with an electronic circuit coupled to an electromechanical system that provides an easy and inexpensive way to record its trajectory. The other two have an air pump fastened to them and use electromechanical system similar to that of the first model. Experiments performed with the three versions that have been constructed are also presented and analyzed.

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