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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

Attitudinal perception of cosmetic wear and damage of materials within the use phase of portable electronic products

Manley, Alan H. G. January 2018 (has links)
During the use phase of products, a series of obsolescing factors contribute to why a product is disposed of. Currently the visual state of a product is considered primarily in terms of aesthetic obsolescence which is synonymous with influential factors such as changes in fashion or personal preferences in style. The physical condition of a product is not commonly understood within the context of product replacement and the physical changes due to use are not understood fully. The research contributes to and provides original empirical research findings for the current literature on product lifetime extension, material semantics, the circular economy, emotionally durable design and material culture. Through an initial exploratory study (Photographic Analysis (PA) Study) of previously unexplained types of wear and damage that occur on portable electronic devices a taxonomy of damage (TOD) was established which provided the nomenclature for further studies. The second study (Retrospective Assessment (RA) Study) established the attitudes to wear based on the wear type, location, material and the stage during ownership that the wear occurred at. The RA Study highlighted the differences in the attitudinal responses to differing types of wear and damage and identified the differences in the temporal assessments of wear and damage. A third study (Real Time Assessment (RTA) Study) aimed to confirm or repudiate the findings found in the RA Study. The focus during the study was attitudes to the wear and damage in relation to the differences in materials, the location of the wear and the type of wear and damage was also looked at and led to a fuller understanding of how products and materials are perceived during the use phase; a stage of the product lifetime that is not currently well understood in terms of users aesthetic or cosmetic sensibilities. The final study (Semantic Perception of Materials (SPM) Study) focused on the visual and tactile perceptions of materials. The study established attitudinal perceptions of wear and damage of materials with a quantitative research methodology which has produced a better understanding of material semantics within the context of electronic objects. Through the four studies, discussion topics arose and major findings of the doctoral study were drawn out and seen to be interesting enough for further research and study. These discussions include the importance of including cosmetic obsolescence into the lexicon of product obsolescence and product lifetime extension literature, the differences in the perceptions of materials when they are within the context of a product or being assessed as samples, how differing product contexts affect user perceptions of wear and damage on materials and the potential inclusion of a material wear index that could inform the material selection process that goes further than the technical aspects outlined in current material selection tools and literature.
2

Avaliação da resistência ao desgaste de uma resina composta odontológica nanoparticulada empregando diferentes tempos de fotopolimerização

Souza, Celso Naves de [UNESP] 10 November 2009 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:32:51Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-11-10Bitstream added on 2014-06-13T19:22:34Z : No. of bitstreams: 1 souza_cn_dr_guara.pdf: 5417862 bytes, checksum: 45f7392a335fde8b9a67ef7d60be0ce9 (MD5) / Este trabalho tem como objetivo avaliar a influência dos tempos de fotopolimerização nas resinas odontológicas, onde quatro resinas compostas foram utilizadas, sendo três micro híbridas e uma nanoparticulada. Esses compósitos foram submetidos ao desgaste abrasivo de esfera rotativa pelo método de ball cratering. Para tal ação foi projetado e construído um dispositivo de desgaste por micro abrasão de esfera rotativa livre de três corpos. Os corpos de prova foram confeccionados e embutidos em uma matriz de alumínio, com uma profundidade de 2mm. Usam-se o aparelho LED RADII, com os tempos de exposição de 20, 30 e 40 segundos e uma esfera com 15 mm de diâmetro de aço temperada, retificada e revenida. A lama abrasiva utilizada nesse estudo foi uma solução composta por 20% de talco (USP/200) e 80% de soro fisiológico, na quantidade de 3 gotas por segundo. Para comprovação dos resultados obtidos, utilizaram-se os testes de: Espectroscopia por Dispersão de Energia (EDS), Infravermelho por Transformada de Fourier (FT-IR), Análise Termogravimétrica (TGA), micro dureza Vickers, ensaio de desgaste de micro abrasão por esfera rotativa pelo método de ball cratering e a análise da superfície desgastada por Microscopia Eletrônica de Varredura (MEV). Esta análise foi realizada para verificar o real mecanismo de desgaste ocorrido. Os resultados obtidos comprovam que o tempo recomendado pelos fabricantes, tem a capacidade suficiente de fotopolimerizar toda a matriz orgânica, comprovaram também que a resina nanoparticulada obteve em todos os ensaios os melhores resultados em relação às resinas híbridas, e que a cultura do acréscimo de até 20s além do recomendado não tem influência direta em relação ao desgaste abrasivo. / This work has as an objective to evaluate the influence of photopolymerization in odontological resins, where composed four resins were used, being three of them micro hybrid and one nanoparticulated. These composites were submitted to abrasive wear and tear of rotative sphere by the method ball cratering. For such action a device of micro abrasion of rotative sphere was designed and built free of three bodies. The bodies of proof were produced and put in a matrix of aluminum with a depth of 2mm. The device used was a LED RADII, with exposition time of 20, 30 and 40 seconds and a sphere of 15mm diameter made of tempered steel, rectified and soften, the abrasive lama used in this study was a solution composed by 20% of powder (USP/200) and 80% of physiological serum released at 3 drops per second. For verification of the results obtained the tests of Energy Dispersion Spectrograph (EDS) was used, transformed Infra red of Fourier (FT-IR), Thermogravimetric Analysis (TGA) Vickers micro hardness, wear and tear of micro abrasion by rotative sphere by the method ball cratering and the analysis of worn superficies by Sweeping Electronic Microscopy (SEM). This analysis was carried out to verify the real mechanism of the worn occurred. The results obtained prove that the time recommended by the manufacturer has enough capacity to photopolymerized all the organic matrix, it also proved that the resin nanoparticulated obtained in all the essays the best results in what concerns to the hybrid resins. And the culture of the addition of 20 seconds besides what is recommended has no direct influence in relation to the abrasive wear and tear.
3

Avaliação da resistência ao desgaste de uma resina composta odontológica nanoparticulada empregando diferentes tempos de fotopolimerização /

Souza, Celso Naves de. January 2009 (has links)
Orientador: Ana Paula Rosifini Alves Claro / Banca: Edson Cocchieri Botelho / Banca: Carlos Roberto Grandini / Banca: Sandra Giacomin Schneider / Banca: Sergio Scheneider / Resumo: Este trabalho tem como objetivo avaliar a influência dos tempos de fotopolimerização nas resinas odontológicas, onde quatro resinas compostas foram utilizadas, sendo três micro híbridas e uma nanoparticulada. Esses compósitos foram submetidos ao desgaste abrasivo de esfera rotativa pelo método de ball cratering. Para tal ação foi projetado e construído um dispositivo de desgaste por micro abrasão de esfera rotativa livre de três corpos. Os corpos de prova foram confeccionados e embutidos em uma matriz de alumínio, com uma profundidade de 2mm. Usam-se o aparelho LED RADII, com os tempos de exposição de 20, 30 e 40 segundos e uma esfera com 15 mm de diâmetro de aço temperada, retificada e revenida. A lama abrasiva utilizada nesse estudo foi uma solução composta por 20% de talco (USP/200) e 80% de soro fisiológico, na quantidade de 3 gotas por segundo. Para comprovação dos resultados obtidos, utilizaram-se os testes de: Espectroscopia por Dispersão de Energia (EDS), Infravermelho por Transformada de Fourier (FT-IR), Análise Termogravimétrica (TGA), micro dureza Vickers, ensaio de desgaste de micro abrasão por esfera rotativa pelo método de ball cratering e a análise da superfície desgastada por Microscopia Eletrônica de Varredura (MEV). Esta análise foi realizada para verificar o real mecanismo de desgaste ocorrido. Os resultados obtidos comprovam que o tempo recomendado pelos fabricantes, tem a capacidade suficiente de fotopolimerizar toda a matriz orgânica, comprovaram também que a resina nanoparticulada obteve em todos os ensaios os melhores resultados em relação às resinas híbridas, e que a cultura do acréscimo de até 20s além do recomendado não tem influência direta em relação ao desgaste abrasivo. / Abstract: This work has as an objective to evaluate the influence of photopolymerization in odontological resins, where composed four resins were used, being three of them micro hybrid and one nanoparticulated. These composites were submitted to abrasive wear and tear of rotative sphere by the method ball cratering. For such action a device of micro abrasion of rotative sphere was designed and built free of three bodies. The bodies of proof were produced and put in a matrix of aluminum with a depth of 2mm. The device used was a LED RADII, with exposition time of 20, 30 and 40 seconds and a sphere of 15mm diameter made of tempered steel, rectified and soften, the abrasive lama used in this study was a solution composed by 20% of powder (USP/200) and 80% of physiological serum released at 3 drops per second. For verification of the results obtained the tests of Energy Dispersion Spectrograph (EDS) was used, transformed Infra red of Fourier (FT-IR), Thermogravimetric Analysis (TGA) Vickers micro hardness, wear and tear of micro abrasion by rotative sphere by the method ball cratering and the analysis of worn superficies by Sweeping Electronic Microscopy (SEM). This analysis was carried out to verify the real mechanism of the worn occurred. The results obtained prove that the time recommended by the manufacturer has enough capacity to photopolymerized all the organic matrix, it also proved that the resin nanoparticulated obtained in all the essays the best results in what concerns to the hybrid resins. And the culture of the addition of 20 seconds besides what is recommended has no direct influence in relation to the abrasive wear and tear. / Doutor
4

Procedural generation and weathering of building facades : Replicating shape and distribution of wear-and-tear on real-world building facades / Procedurell generering och slitage av byggnadsfasader : Replicering av spridning och form av slitage på riktiga byggnader

Wessman, Love January 2023 (has links)
Manual modeling of building facades can be a cumbersome process. Instead, procedurally modeling building facades is a practical and quick way to achieve impressive visual results. This paper presents a method for prototyping 2D facades existing in a 3d environment, with the inclusion of shading-based procedural wear-and-tear. State of the art procedural modeling techniques, despite achieving impressive results in general, are lacking in certain specific areas. Urban planners may wish to model the effects of wear-and-tear along with geometric assets and materials on a facade, to prototype future appearances. As of now, a syncretism between a grammar-based procedural modeling system and a procedural wear-and-tear system is relatively unexplored. Exploring how wear-and-tear can replicate damage found on real buildings, and limitations of the used approach, is the primary goal of this research. Furthermore, this work investigates how wear-and-tear can be incorporated into a procedural building facade generation pipeline. Introducing new wear-and-tear functionality to established systems is done by expanding on grammar-like structures to define building shapes, and adding new actions to produce wear-and-tear, which is done by creating textures representing positions of structural components of the facade, and altered and mixed with noise to create damaging effects. The result is a user interface that can combine procedural building modeling with procedural wear-andtear. It can replicate many types of wear-and-tear, such as rust and cracks, although damage such as stains without visible sources or flow-shaped damage is inadequate. The facades accompanying the wear-and-tear are also able to be produced, but is limited in terms of 3D geometric expressibility due to a focus on flat, 2D facades and a deficiency in future flexibility since wear-and-tear cannot be selected in future actions. / Manuell modellering av fasader kan vara en besvärlig process. Istället är procedurell modellering av fasader ett praktiskt och snabbt sätt att uppnå imponerande visuella resultat. I den här rapporten presenteras en metod för prototypering av 2D-fasader som existerar i en 3D-miljö, med inkludering av skuggningsbaserat procedurellt slitage. Den senaste tekniken för procedurell modellering ger generellt sett imponerande resultat, men brister inom vissa specifika områden. Stadsplanerare kan vilja modellera effekterna av slitage tillsammans med geometriska objekt och material på en fasad för att skapa prototyper av framtida utseende. Hittills är synkretismen mellan ett grammatikbaserat procedurmodelleringssystem och ett procedurbaserat slitagesystem relativt outforskat. Det primära målet med denna forskning är att undersöka hur slitage kan replikera skador som finns på verkliga byggnader och begränsningar av det använda tillvägagångssättet. Dessutom undersöks hur slitage kan integreras i en procedurell pipeline för fasadgenerering av byggnader. Införandet av ny funktionalitet för slitage i etablerade system genomförs genom att utöka grammatikliknande strukturer för att definiera byggnadsformer och lägga till nya åtgärder för att åstadkomma slitage, vilket sker genom att skapa texturer som representerar positioner för strukturella komponenter i fasaden, och som förändras och blandas med brus för att skapa skadeeffekter. Resultatet är ett användargränssnitt som kan kombinera procedurell byggnadsmodellering med procedurell slitage. Det kan replikera flera typer av slitage, t.ex. rost och sprickor, dock är skapandet av skador som fläckar utan synliga källor eller flödesformade skador otillräckligt. De fasader som ackompanjerar slitaget kan också framställas procedurellt med detta verktyg, men är begränsade när det gäller uttryck i 3 dimensioner på grund av fokus på platta 2D-fasader och bristande framtida flexibilitet eftersom producerat slitage inte kan utnyttjas i framtida vidare slitageeffekter.
5

Prohibition of wear and tear allowance on structures of a permanent nature

Khwela, William 24 July 2013 (has links)
M.Comm. (South African & International Taxation) / The capital allowance mentioned in section 11(e) of Income Tax Act 58 of 1962 (“the Act”) refers to machinery, plant, implements, utensils and articles, the value of which may have diminished by reason of wear and tear or depreciation. The machinery, plant, and articles in question, often accede to other assets of a permanent nature such as immovable buildings. This is a problem in South Africa because the wear and tear allowance is lost when machinery, plant or articles lose their identities upon being absorbed into assets of a permanent nature such as a building. Buildings and other structures of a permanent nature do not qualify for the wear and tear allowance in terms of section 11(e) of the Act. This article investigates the uncertainties with regard to interpreting what constitutes “buildings, or other structures or works of a permanent nature” for the purposes of the prohibition of wear and tear allowances contained in section 11(e)(ii) of the Act.
6

Porovnání cen venkovních úprav na pozemku ve funkčním celku s rodinným domem stanovených nákladovým a zjednodušeným způsobem ve vybrané lokalitě v Brně / Comparison of Prices for External Works on a Land Parcel in a Functional Unit with a Family House Determined via the Cost Method and in a Simplified Manner at a Chosen Location in Brno

Říha, Milan January 2012 (has links)
The aim of the thesis is to assess the influence of the exterior finish works on the total price of a house. The total price of the house consists of the interior price valuated by the cost method and the price of the exterior finishes which were valuated with the help of two methods: the cost method and the simplified method based on the Property Valuation Act. The valuation also covers several periods of time: a new building and 11-, 25-, 50-, 75- and 100-years-old buildings. The thesis focuses on the lifetime of individual parts of the exterior finishes—especially the time after which it is necessary to replace or reconstruct a part. A significant focus was placed on the percents listed in the Act and their correspondence to the actual state. The thesis also deals with the various methods of valuation and their appropriateness in each case. It also mentions the influence of other factors on the price of an estate (the use of different exterior finishes, or a selection of a building location) but these factors were not examined in detail.
7

Optimization of Kaplan turbines for frequency regulation in hybrid hydropower plants

Narkhede, Nayan January 2022 (has links)
The increasing penetration of variable renewable energy sources in the Nordic Power System is causing frequency quality degradation and has increased the importance of primary frequency control provided by hydropower plants. Hydropower is the world’s largest renewable energy source. Its reliability, controllability and dispatchability along with its large storage volume makes it the most important source for providing frequency regulation in the Nordic Power System. Many hydropower plants offering regulating power have Kaplan turbines which have complex mechanical systems. Furthermore, the frequent and fast mechanical movements of the Kaplan turbines, providing frequency regulation causes the problem of wear and tear in the guide vanes and runner blades of the turbines. Kaplan turbines are suitable for stable operation.   To mitigate this problem, a solution of hybrid hydropower plants combined with  battery energy storage systems is investigated in this thesis, where batteries can take care of fast frequency deviations, allowing for a more stable operation of the turbines. The analysis is based on the FCR-N service offered by hydropower plants, because FCR-N is identified as one of the services that requires very fast changes in the output power of the hydropower plant. Modelling and simulation, data analysis and on-site measurement are adopted as main study methods in this thesis.  The simulation models of a hydropower plant and a hybrid hydropower plant are developed for the analysis. The simulation model of the hydropower plant is validated using data from a typical Swedish hydropower plant. Quantification of wear and tear is the main focus of the study. The performance of the hydropower plant and hybrid hydropower plant are compared in terms of wear and tear of turbines, speed of the response of plants to frequency deviations and number of directional changes during the mechanical movements of the turbine. Finally, it is concluded that, addition of batteries with hydropower plants will reduce wear and tear of the turbines as well as improve the frequency quality in the Nordic Power System.
8

Aspects de moyen et long termes dans la genèse et l’évolution des Troubles Musculo- Squelettiques au travail : une recherche dans l’industrie aéronautique / Medium and long term aspects of the genesis and evolution of Work-Related Musculo-Skeletal Diseases : a research in the aeronautics sector

Buchmann, Willy 24 June 2013 (has links)
Cette recherche porte sur la genèse et l’évolution des Troubles Musculo-Squelettiques (TMS) dans un établissement de l’industrie aéronautique. Nous proposons une formalisation de nos résultats regardés par le prisme 1. des régulations construites par les compagnons, 2. des phénomènes d’usure, et 3. des processus de mise à l’abri des compagnons lourdement affectés par des douleurs articulaires.Pour ce faire, nous avons construit une approche compréhensive pluridisciplinaire associant des actions en entreprise (analyses ergonomiques de l’activité, entretiens diachroniques menés avec le médecin du travail du site, reconstitution de parcours professionnels de compagnons reclassés pour raisons de santé) et une approche statistique, par des exploitations de l’observatoire EVREST en œuvre dans le groupe industriel depuis le début des années 2000.Nos résultats proposent un regard sur la genèse des TMS, suggèrent des perspectives de prévention, encouragent à construire une mémoire de l’entreprise, et à analyser l’activité (au niveau micro des opérateurs, comme au niveau de l’entreprise) d’une manière indissociable des temps, entre passé, présent et avenir. / This research aims at studying the genesis and evolution of Musculo Skeletal Diseases (MSD) in a company belonging to the aeronautics sector. We put forward a formalization of our results, examined through the prism of 1. Regulations elaborated by the workers, 2. Wear and tear phenomena, and 3. Sheltering processes for workers suffering from serious joint diseases.We have therefore built a comprehensive multidisciplinary approach, associating studies at the workshop level (ergonomic job analyses, diachronic interview carried out with the participation of company’s job physician, reconstitution of professional courses of workers reallocated because of health disorders) and a statistical approach, using the “Evrest” Observatory, undertaken in this industrial group from 2000 on.Our results provide a view of the genesis of MSD, suggest avenues for prevention, encourage to build a memory inside the company, and to analyze activity (at the micro level of workstations, as well as at company level) without separating past, present, and future periods.
9

Avaliação da relação entre as queixas e os agravos à saúde dos cortadores de cana de açúcar que buscam atendimento médico em serviço público de emergência (estudo de caso realizado em município da região de São José do Rio Preto SP)

Custodio, Wilson José 26 April 2013 (has links)
Made available in DSpace on 2016-06-02T19:52:02Z (GMT). No. of bitstreams: 1 5718.pdf: 19273613 bytes, checksum: 5513939eb0582427e140f188b3104e37 (MD5) Previous issue date: 2013-04-26 / This work aims to perform the analysis of complaints made by workers within the sugar cane cutting business and their correlation with clinical outlook during the emergency care in a public health unit and its relationship to work in the cane. The results found from the survey of the medical records, the laboratory tests, and the interviews with the workers, present the relationships between diagnoses and characteristics of the work process, in addition to determining the absence of care protocol directed to such worker, whom does not find in the public health system of which it is to him constitutionally guaranteed. The disorders related to the work/health relationship and the conditions found that it should allow for redemption of its homeostasis are presented here in order to provoke thought about this dissonance. / Esse trabalho tem como propósito a realização da análise das queixas apresentadas pelos trabalhadores do corte da cana-de-açúcar e suas correlações com o quadro clínico detectado no atendimento de emergência em unidade pública de saúde e sua relação com o trabalho na cana. Os resultados encontrados, a partir do levantamento dos prontuários médicos, da realização de exames laboratoriais e de entrevistas com os trabalhadores, mostram as relações entre os diagnósticos realizados e as características do processo de trabalho, além da determinante ausência de protocolo de atendimento direcionado a esse trabalhador, qual não encontra no serviço público de saúde a assistência que constitucionalmente lhe é garantida. Os distúrbios relacionados à relação trabalho/saúde e as condições encontradas que lhe deveriam permitir o resgate da sua homeostase são aqui apresentados de forma a provocar reflexão a respeito dessa dissonância.
10

Hodnocení stavebního projektu z hlediska celoživotních nákladů / Evaluation of Construction Project from aspect of Whole Life Costs

Foitlová, Lucie January 2018 (has links)
The theoretical part deals at the beginning with evaluation of effectiveness of the project, as well as with the information about individual stages of the life cycle of the building, wear and tear of the buildings, lifetime of the elements and whole life costs of the building that are of particular interest to the investor. In conclusion, there are mentioned wastes and emissions. The thesis is completed by a case study of the family house where the whole life costs of the building life cycle are solved.

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