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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.
61

Caracterização de filmes poliméricos utilizados em acabamento de couros

Winter, Cristiana January 2014 (has links)
Artigos de couro estão associados com tendências de moda e sofisticação em produtos de consumo. No processamento do couro, a fase de acabamento consiste de um conjunto de operações e tratamentos, essencialmente de superfície, que conferem características finais ao produto. Os objetivos do acabamento são reduzir defeitos visíveis, modificar as propriedades superficiais e melhorar os atributos de uso. Nesta fase final, são aplicadas, dentre outros produtos, resinas, geralmente, poliacrilatos e poliuretanos, e algumas vezes caseínas e outros polímeros que formam filmes de recobrimento protetores sobre o couro. Nesse contexto, este trabalho visa a uma avaliação dos filmes formados com resinas comerciais utilizadas industrialmente no acabamento de couros, relacionando a composição destes materiais com características sensoriais, com resistência mecânica, através de testes de tração, com estabilidade à água ou a solvente orgânico, com análise de dureza, e através de caracterizações por infravermelho e DSC. Ensaios de tração mostraram que as resinas poliuretânicas, no geral, apresentam uma maior resistência à tração quando comparadas com resinas acrílicas, assim como os valores de tenacidade, indicando que esses filmes suportam um maior impacto para levar o material à ruptura. A adição de pigmentos diminui essa resistência, tanto em resinas acrílicas quanto em resinas poliuretânicas, enquanto que a produção de filmes compactos apresenta características intermediárias com relação aos componentes puros. Todos os filmes acrílicos testados apresentaram uma maior capacidade de alongamento. Com relação à dureza, as resinas que se mostraram mais flexíveis e com maior alongamento, foram as que apresentaram menor dureza. A estabilidade dos filmes com relação à água e solventes mostrou que os componentes solúveis em água e em solvente aumentam com a presença de pigmento e que a absorção de água é maior e de solvente é menor em filmes com pigmento, tanto para acrilatos quanto para poliuretanos. As caracterizações a partir de análise por FTIR e DSC indicaram os grupamentos químicos e picos de temperaturas característicos dos acrilatos e poliuretanos, respectivamente. / Leather goods are associated with fashion trends and sophistication in consumer products. In the leather processing, the finishing phase consists of a series of operations and treatments, essentially in surface, conferring its final characteristics. The objectives are to reduce visible defects, modify surface properties and improve the usage attributes In this final stage are applied, among other products, resins, generally polyacrylates and polyurethanes, sometimes casein and other polymers, which form protective coating films on leather. In this context, this paper evaluates the films formed with commercial polymeric resins used industrially in finishing leather, relating the composition of these materials with their sensory characteristics, with their strength by tensile testing, with its stability to water or organic solvent, with analysis of hardness and characterizations by IR and DSC. Tensile tests showed that the polyurethane resins in general have a higher tensile strength when compared with acrylic resins, as well as the toughness values, indicating that these films support a greater impact to bring the material to rupture. The addition of pigments decreases this resistance, for acrylic resins and polyurethane resins, while the production of compact film has intermediate characteristics with respect to the pure components. All acrylic films tested had a higher elongation. With respect to hardness, the resins that were more flexible and more stretching, showed the lowest hardness. The stability of the films with respect to water and solvents has shown that water soluble solvent components increased by the presence of pigment and the water absorption is higher and the solvent is lower in pigmented films to acrylates and polyurethanes. The characterizations from IR and DSC analysis indicated the chemical groups and characteristic temperatures peaks of acrylates and polyurethanes, respectively.
62

Caracterização de filmes poliméricos utilizados em acabamento de couros

Winter, Cristiana January 2014 (has links)
Artigos de couro estão associados com tendências de moda e sofisticação em produtos de consumo. No processamento do couro, a fase de acabamento consiste de um conjunto de operações e tratamentos, essencialmente de superfície, que conferem características finais ao produto. Os objetivos do acabamento são reduzir defeitos visíveis, modificar as propriedades superficiais e melhorar os atributos de uso. Nesta fase final, são aplicadas, dentre outros produtos, resinas, geralmente, poliacrilatos e poliuretanos, e algumas vezes caseínas e outros polímeros que formam filmes de recobrimento protetores sobre o couro. Nesse contexto, este trabalho visa a uma avaliação dos filmes formados com resinas comerciais utilizadas industrialmente no acabamento de couros, relacionando a composição destes materiais com características sensoriais, com resistência mecânica, através de testes de tração, com estabilidade à água ou a solvente orgânico, com análise de dureza, e através de caracterizações por infravermelho e DSC. Ensaios de tração mostraram que as resinas poliuretânicas, no geral, apresentam uma maior resistência à tração quando comparadas com resinas acrílicas, assim como os valores de tenacidade, indicando que esses filmes suportam um maior impacto para levar o material à ruptura. A adição de pigmentos diminui essa resistência, tanto em resinas acrílicas quanto em resinas poliuretânicas, enquanto que a produção de filmes compactos apresenta características intermediárias com relação aos componentes puros. Todos os filmes acrílicos testados apresentaram uma maior capacidade de alongamento. Com relação à dureza, as resinas que se mostraram mais flexíveis e com maior alongamento, foram as que apresentaram menor dureza. A estabilidade dos filmes com relação à água e solventes mostrou que os componentes solúveis em água e em solvente aumentam com a presença de pigmento e que a absorção de água é maior e de solvente é menor em filmes com pigmento, tanto para acrilatos quanto para poliuretanos. As caracterizações a partir de análise por FTIR e DSC indicaram os grupamentos químicos e picos de temperaturas característicos dos acrilatos e poliuretanos, respectivamente. / Leather goods are associated with fashion trends and sophistication in consumer products. In the leather processing, the finishing phase consists of a series of operations and treatments, essentially in surface, conferring its final characteristics. The objectives are to reduce visible defects, modify surface properties and improve the usage attributes In this final stage are applied, among other products, resins, generally polyacrylates and polyurethanes, sometimes casein and other polymers, which form protective coating films on leather. In this context, this paper evaluates the films formed with commercial polymeric resins used industrially in finishing leather, relating the composition of these materials with their sensory characteristics, with their strength by tensile testing, with its stability to water or organic solvent, with analysis of hardness and characterizations by IR and DSC. Tensile tests showed that the polyurethane resins in general have a higher tensile strength when compared with acrylic resins, as well as the toughness values, indicating that these films support a greater impact to bring the material to rupture. The addition of pigments decreases this resistance, for acrylic resins and polyurethane resins, while the production of compact film has intermediate characteristics with respect to the pure components. All acrylic films tested had a higher elongation. With respect to hardness, the resins that were more flexible and more stretching, showed the lowest hardness. The stability of the films with respect to water and solvents has shown that water soluble solvent components increased by the presence of pigment and the water absorption is higher and the solvent is lower in pigmented films to acrylates and polyurethanes. The characterizations from IR and DSC analysis indicated the chemical groups and characteristic temperatures peaks of acrylates and polyurethanes, respectively.
63

Is Screening for Genuine Leather Possible?

Narayanan, Priya, Sreeram, Kalarical Janardhanan 28 June 2019 (has links)
Content: The value chain of leather is complex and originates from the animal husbandry system to meat processing, pre tanning, tanning, post tanning and product manufacturing processing. The imbibed properties of the material gained from the environmental conditions under which the animal grew to the range of human skills and processing chemicals determines how best the leather products meet the customer desires. The customer desire for feel and handle is ultimately traced back to the origin of the animal itself. Leather thus is a unique product whose properties such as visco-elasticity, breathability etc. remained unmatched by synthetics. Industrialization activities, reduced farming, the vegan culture all have contributed to reduced availability of hides and skins for meeting the quantity of leather required for various end products. This in essence contributed to the growth of a new market for synthetics, wherein the manmade fabrics tried to reproduce all the features of leather, synthetically. Commercially, these products came to be known through various names such as leatherette, faux leather, vegan leather, PU leather, pleather etc. Advancement in material science led to a range of products and manufacturing methods has today ensured that conventional identification techniques such as rough edges, imperfect surfaces, wrinkle test, water absorption, burnability, uneven stitch holes, structure retention, smell, grain pattern can no longer be used to distinguish between leather and similar artificial products. Advancement in technology for the manufacture of various types of leather like materials has made it difficult to identify genuine leather from other leather like materials. With leather like materials meeting most of the conventional methods of identifying genuine leather there is today a need for a new methodology for identifying genuine leather. This paper addresses to a study of a statistically relevant number of samples of leather and non-leather materials through a range of iterative instrumental techniques leading to the establishment of a protocol for identification of genuine leather. The methodology starts with the FTIR-ATR based (non-destructive) identification of signature bands of collagen – the amide I, II and III. After the first level screening, iterative analysis of samples that have the amide bands matching with that of collagen would be screened through techniques such as hydroxyproline estimation, thermogravimetric analysis, fibre structure assessment etc. The paper would report the results, the positives and negatives associated with the first level screening for genuine leather using FTIR. Take-Away: 1. A method for identifying genuine leather. 2. Value addition to leather by way of facile identification. 3. Customer satisfaction.
64

Luxury value perceptions that drive South African female consumers' purchase intent for luxury exotic leather accesories

Scheepers, Sunette January 2016 (has links)
The study investigated South African female consumers' purchase intent for luxury exotic leather accessories, with specific reference to exotic crocodile leather, as well as their perceived values of luxury exotic leather products and brands. A survey was conducted across South Africa that included representation of the following ethnic groups: African, White, Coloured, Asian and Indian. All the individuals surveyed were female. Consulta Research, a consumer research company, assisted the research study in collecting data. Data was collected by means of a non-probability convenient sampling method. Consulta Research distributed an online questionnaire to female participants on their database. Three hundred and thirty seven (337) usable questionnaires were completed and returned. Data analysis consisted of descriptive statistics, exploratory factor analysis, Spearman's correlation analysis and Cohen's d correlation analysis. All of the demographic and lifestyle characteristics were useful in describing the South African female consumer. The findings indicated that the majority of the respondents were not willing to spend market-related prices for genuine crocodile leather accessories. The study confirmed that luxury value perceptions may include five dimensions that are distinguished in literature, namely Social, Individual gifts, Individual pleasure, Financial, and Functional value perceptions. Functional value perceptions were found to be more important to South African respondents, although previous studies in other countries have shown that Social and Individual value perceptions are more important. According to the literature presented in the study, it was confirmed that purchasing intent is part of the decision-making process, since intention is evident in an individual's readiness to perform a given behaviour. The findings showed that South African female respondents have a weak Purchasing intent for exotic crocodile leather accessories. The study, however, also showed that in the future at some point a substantial percentage of respondents might buy (24.00% + 18.60% + 20.70%), have the intention to buy (23.40% + 17.50% + 21.30%) and have an interest to buy (23.10% + 17.80% + 18.90%) an exotic crocodile leather accessory. A high practical significance was also found for the correlation between Purchasing intent and Functional value perceptions. This might be an indicator of the important role that functionality would play in respondents' final decision to buy or not buy an exotic crocodile leather accessory. This has implications for industry stakeholders because Functional value perceptions, according to the study, can be described as superior quality, quality assurance, high quality standards and substantive attributes and performance factors. Therefore industry stakeholders within the luxury exotic crocodile leather industry, be it suppliers, manufacturers, breeders, farmers, retailers or marketers, should take these consumer values into consideration in order to maximise the ultimate value delivered by the supply chain. Various recommendations are made based on the findings of this study, to either expand or build onto this existing research. Topics related to luxury exotic crocodile leather accessories and luxury consumers in South Africa can definitely be explored further to fill the current gap in knowledge in this field. / Dissertation (MConsumer Science)--University of Pretoria, 2016. / Consumer Science / MConsumer Science / Unrestricted
65

Development of Fungal Leather-like Material from Bread Waste

Wijayarathna, Egodagedara Ralalage Kanishka Bandara January 2021 (has links)
Food waste and fashion pollution are two of the significant global environmental issues throughout the recent past. In this research, it was investigated the feasibility of making a leather-like material from bread waste using biotechnology as the bridging mechanism. The waste bread collected from the supermarkets were used as the substrate to grow filamentous fungi species Rhizopus Delemar and Fusarium Venenatum. Tanning of fungal protein fibres was successfully performed using vegetable tanning, confirmed using FTIR and SEM images. Furthermore, glycerol and a biobased binder treatment was performed for the wet-laid fungal microfibre sheets produced. Overall, three potential materials were able to produce with tensile strengths ranging from 7.74 ± 0.55 MPa to 6.92 ± 0.51 MPa and the elongation% from 16.81 ± 1.61 to 4.82 ± 0.36. The binder treatment enhanced the hydrophobicity even after the glycerol treatment, an added functional advantage for retaining flexibility even after contact with moisture. The fungal functional material produced with bread waste can be tailored successfully into leather substitutes using an environmentally benign procedure.
66

O couro de peixe e seus benefícios na indústria têxtil e de confecção / Leather fish and its benefits in the textile and apparel industry

Nobrega, Laura Carolina Oliveira 14 April 2015 (has links)
O presente estudo teve como foco principal a observação dos benefícios do couro de peixe no mercado têxtil e de confecção. Foram comparadas amostras do couro obtido da pele de peixe com o couro bovino principalmente e também com couros oriundos de outros animais. O couro de peixe apresenta resistência superior à dos outros couros, especialmente à do couro bovino, sendo, neste caso, três vezes mais resistente. É também o único couro obtido posteriormente ao abate do animal. No caso específico do peixe, após o animal ser abatido para fins alimentícios, todo o resto da peça é reaproveitado. A pele vira couro, e o esqueleto vira revestimento automotivo e combustível para veículos automotores. Há, portanto, diversas opções de utilização. Ademais, essa utilidade traz benefícios também para o meio ambiente, não somente em decorrência de técnicas de reaproveitamento socioambientais, mas principalmente porque evita-se a poluição de rios e mares com o descarte, sem que sejam gerados entupimentos, poluição, intoxicações e inutilização da água / The main focus of this study is the observation of the benefits brought about by fish leather, specially when it comes to the textile and apparel market. Fish leather samples were compared to bovine leather mainly and to other kinds of leather. Fish leather shows stronger resistance, and it proved to be much stronger than bovine leather specifically, three times stronger. Fish leather is also the only leather to be obtained after the animal is slaughtered. In the specific case of the fish, everything that remains from the leftovers is used after the edible parts of the animal are set apart. Its skin becomes leather; its bones become fuel and coatings for automobiles. Therefore, there are plenty of usage options to be considered. Furthermore, such options are eco-friendly, not only because of the social and environmental reprocessing techniques involved, but also because they prevent the pollution of rivers and seas brought about by irresponsible disposal which may cause clogged drains, pollution, poisoning, and all sorts of contamination of the water
67

cut.suction.remove.suction.sew

CLAUSEN, LAURA January 2011 (has links)
This project is dealing with the human body and surgical modifications. I am wondering how to achieve the aim of provoking compassion, rejection and attraction in one collection. I would like to deeply move the sensation of your own body by showing deformed and reconstructed bodies.Cut off body parts and re-sew them somewhere else…I want to show something that is considered to be disgusting in a context where you would not expect to meet it.Furthermore, I would like to show that anything that looks normal disgusts you in an abnormal size or position.I want people to discover such elements at a second glance and I chose this theme also in order to provoke myself. I was wondering how it would affect my work by chosing a topic that irritates myself.The background for this project is built on a two year research and I am going to highlight the decisions along the way.I do relate my work strongly to Matthew Barneys way of creating and I got influenced by his aesthetics. But also the methods I used were significant for my end result which I am showing in form of clinical reports in which each character and its personal story is described.This report ends with a discussion part where I evaluate the result and my competence. / Program: Master Programme in Fashion Design
68

Uma contribuição ao estudo de evidenciação do efeito da cumulatividade de tributos: o caso da COFINS em quatro estágios de um segmento da cadeia produtiva do couro / A contribution to the study of disclousure effects of cumulativeness of tributes: the case COFINS taxation in four phases of a segment of the leather productive chain.

Rogério Ferreira dos Santos 14 May 2003 (has links)
Este trabalho propõe uma metodologia para evidenciar o efeito da cumulatividade de tributos no preço de venda de um produto ao longo da cadeia produtiva. Foi apresentado um panorama sobre o setor coureiro no Brasil, com o objetivo de identificar os estágios mais relevantes de um segmento da produção do couro e mensurar o efeito da cumulatividade da COFINS que ocorre nesse segmento. Os procedimentos da metodologia contemplam a demonstração do encadeamento do efeito cascata do tributo em cada um dos estágios, mensurando a taxa de majoração do preço de venda do couro que acontece de um agente e o seguinte do segmento. Por meio da metodologia sugerida, foi possível evidenciar que em cada estágio do segmento da cadeia produtiva do couro (produtor, abatedouro, curtume, indústria de artefatos de couro) as taxas de majoração do preço de venda foram 4,27%, 5,56%, 5,23% e 4,97%, respectivamente. A metodologia evidencia, também, que o percentual de 7,91% do preço de venda no último estágio do segmento considerado representa o valor do tributo nele incorporado. Não obstante estes percentuais serem válidos somente para os valores dos preços de cada estágio ilustrados no exemplo deste estudo, a metodologia poderá ser utilizada para apurar os percentuais de outros estágios e segmentos. / This work suggests a methodology to disclosure effects of the cumulative taxes on the selling prices along the supply chain. We presented a panorama about the leather production segment in Brasil aiming to identify the main phases of the leather production process by measuring the effects of COFINS taxation that occurs in the segment. The methodological procedures adopted here allow us to verify the cumulative taxation in each referred phase by measuring the rate of in crease of the leather selling prices which occurs from one element to the following one of the supply chain, Through the methodology suggested we achieved to demonstrate that in each of the leather production phase (producer, slaughter, tannery, leather company) the increasing rates of selling prices was 4,27%, 5,56%, 5,23% and 4,97%, respectively. The method also indicates that the increasing rate of 7,91% on the selling prices relatives to the last phase correspond to the amount of tax added to the product. Though these percentage are valid only for these example utilized in this work, we conclude that this methodology applies to other cases and segments.
69

Maputo declaration on the textiles, clothing and leather industries

Worker representatives January 1900 (has links)
The massive job losses and factory closures in the clothing, textiles and leather industries in almost all countries in the region. The low wages that continue in our industries, resulting in a low and, in many instances, declining standard of living of workers. The crisis which face unemployed workers who have no income, no social security net, and no immediate prospect of a job. It is a fundamental responsibility of governments in the region to work with trade unions and employers in order to develop appropriate policies to secure a future for the industries and to improve the conditions of workers.
70

Uma contribuição ao estudo de evidenciação do efeito da cumulatividade de tributos: o caso da COFINS em quatro estágios de um segmento da cadeia produtiva do couro / A contribution to the study of disclousure effects of cumulativeness of tributes: the case COFINS taxation in four phases of a segment of the leather productive chain.

Santos, Rogério Ferreira dos 14 May 2003 (has links)
Este trabalho propõe uma metodologia para evidenciar o efeito da cumulatividade de tributos no preço de venda de um produto ao longo da cadeia produtiva. Foi apresentado um panorama sobre o setor coureiro no Brasil, com o objetivo de identificar os estágios mais relevantes de um segmento da produção do couro e mensurar o efeito da cumulatividade da COFINS que ocorre nesse segmento. Os procedimentos da metodologia contemplam a demonstração do encadeamento do efeito cascata do tributo em cada um dos estágios, mensurando a taxa de majoração do preço de venda do couro que acontece de um agente e o seguinte do segmento. Por meio da metodologia sugerida, foi possível evidenciar que em cada estágio do segmento da cadeia produtiva do couro (produtor, abatedouro, curtume, indústria de artefatos de couro) as taxas de majoração do preço de venda foram 4,27%, 5,56%, 5,23% e 4,97%, respectivamente. A metodologia evidencia, também, que o percentual de 7,91% do preço de venda no último estágio do segmento considerado representa o valor do tributo nele incorporado. Não obstante estes percentuais serem válidos somente para os valores dos preços de cada estágio ilustrados no exemplo deste estudo, a metodologia poderá ser utilizada para apurar os percentuais de outros estágios e segmentos. / This work suggests a methodology to disclosure effects of the cumulative taxes on the selling prices along the supply chain. We presented a panorama about the leather production segment in Brasil aiming to identify the main phases of the leather production process by measuring the effects of COFINS taxation that occurs in the segment. The methodological procedures adopted here allow us to verify the cumulative taxation in each referred phase by measuring the rate of in crease of the leather selling prices which occurs from one element to the following one of the supply chain, Through the methodology suggested we achieved to demonstrate that in each of the leather production phase (producer, slaughter, tannery, leather company) the increasing rates of selling prices was 4,27%, 5,56%, 5,23% and 4,97%, respectively. The method also indicates that the increasing rate of 7,91% on the selling prices relatives to the last phase correspond to the amount of tax added to the product. Though these percentage are valid only for these example utilized in this work, we conclude that this methodology applies to other cases and segments.

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