Tesis sobre el tema "Rope. Textile fibers, Synthetic"
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Hong, Joohyun. "Structure-process-property relationships in polyester spun yarns : the role of fiber friction". Diss., Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/10118.
Texto completoRamesh, Ram Kumar. "Solution-based formation of continuous SiC fibers". Thesis, Georgia Institute of Technology, 1991. http://hdl.handle.net/1853/11130.
Texto completoPerkins, Cheryl Anne. "Physical characterization of meltblown fibers". Thesis, Georgia Institute of Technology, 1989. http://hdl.handle.net/1853/10986.
Texto completoZhang, Yi. "Solution studies on soybean protein for fiber spinning". Thesis, Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/10287.
Texto completoLaton, Michael A. "Behavior of twisted fiber bundles under dynamic testing conditions". Thesis, Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/8586.
Texto completoTshifularo, Cyrus Alushavhiwi. "Comparative performance of natural and synthetic fibre nonwoven geotextiles". Thesis, Nelson Mandela Metropolitan University, 2017. http://hdl.handle.net/10948/21362.
Texto completoMiller, Leah Margaret. "Characterization of extended chain polyethylene/S-2 glass, interply hybrid, fabric composites". Thesis, Georgia Institute of Technology, 1988. http://hdl.handle.net/1853/8623.
Texto completoYang, Fang. "Synthesis and characterization of star-like poly(p-hydroxybenzoic acid)-co-poly(m-hydroxybenzoic acid-co-poly(2-hydroxy-6-napthoic acid)". Thesis, Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/8711.
Texto completoGilmore, Laurie Ann. "Chlorination of synthetic dyes and synthetic brighteners". Thesis, Georgia Institute of Technology, 1991. http://hdl.handle.net/1853/20794.
Texto completoReddy, Srinath. "Structure and properties of melt spun poly(4-methyl-1-pentene) fibers". Thesis, Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/10204.
Texto completoMusch, Janelle C. Riemersma. "Design optimization of sustainable panel systems using hybrid natural/synthetic fiber reinforced polymer composites". Diss., Connect to online resource - MSU authorized users, 2008.
Buscar texto completoTitle from PDF t.p. (viewed on Aug. 3, 2009) Includes bibliographical references (p.129-132). Also issued in print.
Kumar, Amit. "Application of near infrared reflectance spectroscopy to detection of heat set temperature of carpet yarn". Thesis, Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/8579.
Texto completoNatarajan, Subashree. "Characterization of poly(ethylene terephthalate) fibers using raman microscopy". Thesis, Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/8646.
Texto completoSeckin, M. Levent. "Effect of superba heatsetting on dyeing behavior of nylon 6,6 carpet yarns". Thesis, Georgia Institute of Technology, 1985. http://hdl.handle.net/1853/8268.
Texto completoGupta, Murari Lal. "Development of commercial, sustainable processes for dyeing generic, unmodified polypropylene fiber". Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/26643.
Texto completoCommittee Chair: Cook, Fred; Committee Member: Beckham, Haskell; Committee Member: Bottomley, Lawrence; Committee Member: Carr, Wallace; Committee Member: Etters, Nolan. Part of the SMARTech Electronic Thesis and Dissertation Collection.
LeBoeuf, Leighton Lee Jr. "Investigation of rabid low temperature depolymerization of polyethylene terephthalate : a novel approach". Thesis, Georgia Institute of Technology, 1988. http://hdl.handle.net/1853/8588.
Texto completoJacobs, Nokwindla Valencia. "Optimising the polymer solutions and process parameters in the electrospinning of Chitosan". Thesis, Nelson Mandela Metropolitan University, 2012. http://hdl.handle.net/10948/d1010762.
Texto completoGnesa, Eric Henry. "The conserved C-terminal domain of spider tubuliform spidroin 1 contributes to extensibility in synthetic fibers". Scholarly Commons, 2011. https://scholarlycommons.pacific.edu/uop_etds/771.
Texto completoLi, Haiying. "A study on grafting poly(p-phenylene terephthalamide) with aliphatic amines and amides". Thesis, Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/8594.
Texto completoLambert, Karen A. "Solution studies of soybean protein isolate using circular dichroism and SDS-PAGE". Thesis, Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/9495.
Texto completoVohra, Sanjay. "A mechanics framework for modeling fiber deformation on draw rollers and freespans". Diss., Available online, Georgia Institute of Technology, 2006, 2006. http://etd.gatech.edu/theses/available/etd-05172006-141347/.
Texto completoKarl I. Jacob, Committee Chair ; Youjiang Wang, Committee Member ; Mary Lynn Realff, Committee Member ; Arun Gokhale, Committee Member ; Rami Haj-Ali, Committee Member.
Connor, Daniel Martin. "Design and synthesis of comonomers to enhance the optical, physical, and thermal properties of poly(ethylene terephthalate)". Diss., Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/29882.
Texto completoKvaratskheliya, Varvara A. "A study of microstructural changes in synthetic fibres resulting from mechanical deformations". Thesis, De Montfort University, 2001. http://hdl.handle.net/2086/4906.
Texto completoGeurts, Paul. "The Synthetic spider silk fibers spun from Pyriform Spidroin 2, a glue silk protein discovered in orb-weaving spider attachment discs". Scholarly Commons, 2010. https://scholarlycommons.pacific.edu/uop_etds/759.
Texto completoThio, Beng Joo Reginald. "Characterization of bioparticulate adhesion to synthetic carpet polymers with atomic force microscopy". Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/31727.
Texto completoCommittee Chair: J. Carson Meredith; Committee Member: Amyn Teja; Committee Member: F. Joseph Schork; Committee Member: Lawrence Bottomley; Committee Member: Mark Prausnitz. Part of the SMARTech Electronic Thesis and Dissertation Collection.
Thompson, Kimberlee Fay. "Modification of polymeric substrates using surface grafted nanoscaffolds". Diss., Available online, Georgia Institute of Technology, 2005, 2005. http://etd.gatech.edu/theses/available/etd-05162005-165302/.
Texto completoCarter, W. Brent, Committee Member ; Cook, Fred, Committee Member ; Griffin, Anselm, Committee Member ; Michielsen, Stephen, Committee Chair ; Beckham, Haskell, Committee Member ; Bottomley, Lawrence, Committee Member.
De, Bruin Riette. "Die versoenbaarheid van katoen/nylon- en katoen/poliester- skeringgebreide terriestofhanddoeke met industriele versorgingsprosedures". Thesis, Stellenbosch : University of Stellenbosch, 2011. http://hdl.handle.net/10019.1/16604.
Texto completoENGLISH ABSTRACT: The aim of the study was to investigate the compatibility of cotton/nylon and cotton/polyester warpknit terry towelling fabrics with industrial laundering procedures. The literature review focused, on the one hand, on the manufacture, finishing and structure of warp-knit terry towelling fabrics as well as on the physical structure, chemical nature and characteristics of the textile fibres used in the manufacturing of the towelling. On the other hand, a full exposition of the industrial laundering processes is provided, with specific reference to aspects that can have an effect on the towelling fabrics during the wash and tumble-drying cycles. Chapters Three and Four are reports on two research projects that can each be read independently. The aim of the first project was to determine the effect of industrial laundering procedures on the durability of cotton warp-knit terry towelling fabrics with a synthetic base structure. The tensile strength of cotton warp-knit terry towelling samples with a synthetic base structure was determined in the warp and weft directions and after 10, 20, 30, 40, and 50 wash cycles as well as wash and tumble-drying cycles. The tensile strengths in the warp direction of the washed terry towelling samples decreased significantly (p < 0.001) after 50 wash cycles. In contrast to this, the tensile strength in the weft direction increased, although not significantly (p > 0.05). As far as the comparison of the effect of industrial wash and wash and tumble-drying cycles is concerned, the tensile strengths in the warp direction of the towelling samples that were washed and washed/tumble-dried, were significantly lower (p < 0.001) after 20 and after 50 laundering cycles. As far as the tensile strengths in the weft direction were concerned, a similar pattern as with the wash and wash/tumble-drying processes, occurred. The tensile strengths initially increased and then gradually decreased. Furthermore, the tumble-drying process had greater damaging effects after 40 laundering cycles (p = 0.043) and especially after 50 laundering cycles (p < 0.0001). The aim of the second research project was to compare the durability of cotton warp-knit terry towelling fabrics with a nylon base structure with cotton warp-knit terry towelling fabrics with a polyester base structure after they had been subjected to industrial laundering processes. It was first established whether cotton/nylon and cotton/polyester warp-knit terry towelling fabrics are comparable. Secondly, the durability of cotton/nylon and cotton/polyester terry towelling fabrics was compared by determining the tensile strengths of the samples in the warp direction after they have been subjected to 50 industrial wash as well as wash and tumble-drying cycles. The two groups of untreated samples were regarded as similar on the basis of the percentage of fibre composition, knit fabric structure, knit density, mass and tensile strength. After 50 industrial wash cycles the tensile strengths of the cotton/nylon and cotton/polyester warp-knit terry towelling samples decreased significantly (p < 0.05). But there was no significant difference (p > 0.05) between the tensile strengths of the cotton/nylon and the cotton/polyester terry towelling samples after 50 washing cycles. There was a highly significant difference (p < 0.001) between the tensile strengths of the cotton/nylon and the cotton/polyester terry towelling samples after 50 wash and tumble-drying cycles. The tensile strength of the cotton/polyester terry towelling samples remained practically unchanged after the 50 wash/tumble-drying cycles, with the tensile strength of the cotton/nylon terry towelling samples decreased significantly (p < 0.001).
AFRIKAANSE OPSOMMING: Die doel van die studie was om ondersoek in te stel na die versoenbaarheid van katoen/nylon- en katoen/poliëster- skeringgebreide terriestofhanddoeke met industriële versorgingsprosedures. In die literatuuroorsig is daar enersyds gefokus op die vervaardiging, afwerking en struktuur van skeringgebreide terriehanddoekstowwe asook op die fisiese struktuur, chemiese aard en eienskappe van die tekstielvesels waarvan die handdoeke vervaardig is. Andersyds is ’n volledige uiteensetting van industriële versorgingsprosedures gegee, met spesifieke verwysing na aspekte wat tydens die was- en tuimeldrogingsiklusse ’n uitwerking op die handdoekstowwe kan hê. Hoofstukke drie en vier is opgeskryf as twee navorsingsprojekte wat elk ‘n geheel vorm. Die doel van die eerste projek was om die effek van industriële versorgingsprosedures op die duursaamheid van katoen skeringgebreide terriestofhanddoeke met ‘n sintetiese basisstruktuur te bepaal. Die breeksterkte van katoen skeringgebreide terriestofmonsters met ’n sintetiese basisstruktuur is in die skering- en inslagrigtings tydens en na afloop van 10, 20, 30, 40, en 50 was- asook was- en tuimeldrogingsiklusse bepaal. Die breeksterktes in die skeringrigting van die gewaste terriestofmonsters het betekenisvol afgeneem (p < 0.001) na 50 wassiklusse. In teenstelling hiermee het die breeksterktes in die inslagrigting toegeneem, hoewel nie betekenisvol nie (p > 0.05). Wat die vergelyking van die effek van industriële was- en was en tuimeldrogingsiklusse betref, is die breeksterktes in die skeringrigting van die handdoekmonsters wat gewas en gewas/getuimeldroog is, beduidend laer (p < 0.001) na 20 en na 50 versorgingsiklusse. Wat die breeksterktes in die inslagrigting betref het ‘n soortgelyke patroon by die was- en was/tuimeldrogingprosesse voorgekom. Die breeksterktes neem aanvanklik toe en daarna geleidelik af. Verder het die tuimeldrogingsproses na 40 versorgingsiklusse (p = 0.043) en veral na 50 versorgingsiklusse (p < 0.0001) ’n groter skadelike effek getoon. Die doel van die tweede navorsingsprojek was om die duursaamheid van katoen skeringgebreide terriestowwe met ’n nylon basisstruktuur te vergelyk met katoen skeringgebreide terriestowwe met ’n poliëster basisstruktuur nadat dit aan industriële versorgingsprosedures blootgestel is. Daar is eerstens vasgestel of katoen/nylon en katoen/poliëster terriehanddoekstowwe vergelykbaar is. Tweedens is die duursaamheid van katoen/nylon en katoen/poliëster terriestowwe vergelyk deur die breeksterktes van die monsters in die skeringrigting te bepaal nadat dit aan 50 industriële wasasook was- en tuimeldrogingsiklusse blootgestel is. Die twee groepe onbehandelde monsters is as soortgelyk beskou op grond van die persentasie veselsamestelling, breistofstruktuur, breidigtheid, massa en breeksterkte. Na 50 industriële wassiklusse het die breeksterktes van die katoen/nylon en katoen/poliëster skeringgebreide terriestofmonsters betekenisvol (p < 0.05) afgeneem. Daar was egter nie ’n betekenisvolle verskil (p > 0.05) tussen die breeksterktes van die katoen/nylon en katoen/poliëster terriestofmonsters na 50 wassiklusse nie. Daar was ’n hoogs betekenisvolle verskil (p < 0.001) tussen die breeksterktes van die katoen/nylon en katoen/poliëster terriestofmonsters na die 50 was/tuimeldrogingsiklusse. Die breeksterkte van die katoen/poliëster terriestofmonsters het na die 50 was/tuimeldrogingsiklusse feitlik onveranderd gebly terwyl die breeksterkte van die katoen/nylon terriestofmonsters hoogs betekenisvol (p < 0.001) afgeneem het.
Modh, Haresh A. "Chemical treatment and adhesion in internally reinforced rayon fibers". Ohio : Ohio University, 1988. http://www.ohiolink.edu/etd/view.cgi?ohiou1182867766.
Texto completoThio, Beng Joo Reginald. "Quantification of Bioparticulate Adhesion to Synthetic Carpet Polymers with Atomic Force Microscopy". Thesis, Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/14028.
Texto completoGiordano, João Batista. "Tratamento corona sobre superficies texteis". [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/266145.
Texto completoTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica
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Resumo: Dentre as técnicas de modificação de superfícies aplicadas na indústria para melhorar adesão, o tratamento por descarga corona é amplamente utilizado. Durante o tratamento por descarga coro na, espécies ativas são geradas, as quais podem reagir com a superfície do polímero ocasionando quebra de cadeias e formação de radicais, criando assim grupos polares na superfície e conseqüentemente, aumentando a sua energia superficial e propriedade de adesão. Neste trabalho utilizaram-se tecidos de poliéster e de algodão. Nos processos convencionais de preparação de tecidos são usados agentes químicos que agridem os efluentes têxteis, assim a descarga corona propõe-se como tratamento prévio do material sem ação de tais agentes, sendo tratamento único e apenas físico. Os objetivos deste trabalho são: 1. Tratar com descarga corona tecidos de poliéster e tecidos de algodão (engomado, lavado e desengomado); 2. Verificar hidrofilidade e absorção de corantes em tecidos de algodão tratados com descarga corona; 3. Verificar propriedades mecânicas em tecidos tratados com descarga corona. 4. Verificar a adesão de pigmentos em de tecidos de poliéster tratados com corona. Tecidos foram submetidos à descarga: corona variando-se o tempo exposição e altura entre os eletrodos, em seguida foi realizada testes de hídrofilidade, absorção de corante tipo reativo, adesão de pigmentos, solidez a lavagem e ensaios de resistência à tração e alongamento. Foi utilizada a técnica de microscopia óptica, ensaio de hidrofilidade para caracterizar os efeitos causados. Os resultados mostram que: houve aumento da hidrofilidade do tecido de algodão que de 50% em amostra sem tratamento passou até a 280% com o tratamento, observou-se também que com te~pos de 1 mino já ocorrem modificações nos tecidos quanto a hidrofilidade e absorção de corantes; houve aumento da absorção de corante nas regiões tratadas principalmente em processos contínuos de tingimento; ocorreu boa aderência de pigmentos em tecidos de poliéster tratados; não ocorrem alteração das propriedades mecânicas (resistência a tração e alongamento) nas amostras tratadas.
Abstract: Amongst the techniques of modification of surfaces applied in the industry to improve adhesion, the treatment for discharge corona widely is used. During the treatment for discharge corona, active species are generated, which can consequently react with the surface of polymer causing chain in addition and formation of radicals, thus creating polar groups in the surface and, increasing its superficial energy and property of adhesion. In this work they had been used weaveed of polyester and cotton. In the conventional processes of fabric preparation they are used chemical agents whom the effluent textile attack, thus the discharge corona is considered as previous treatment of the material without action of such agents, being treatment only e only physicist. The objectives of this work are: 1.To deal with discharge corona weaveed to polyester and fabrics cotton (starchy, washed and dissolved the gum); 2. To verify water absorption and absorption of corantes in fabrics of cotton treated with discharge corona; to 3.Verificar mechanical properties in fabrics dealt with discharge corona. 4. To verify the pigment adhesion in of treated polyester fabrics with corona. Fabrics had been submitted to the discharge corona varying the time exposition and height between the electrodes and, after that water absorption tests had been carried through, absorption of corante reactive type, pigment adhesion, solidity the laudering and assays of tensile strenght and allonge. The technique of optic microscopy was used, assay of water absorption to characterize the caused effect. The results show that: it had increase of the hidrofilidade of the cotton fabric that of 50% in sample without treatment passed until 280% with the treatment, was 9.lso observed that with times of 1 min. already the water absorption and absorption of corantes occur modifications in fabrics how much; it had increase of the absorption of corante in the regions treated mainly in continuous processes of dyeing good pigment tack occurred in treat polyester fabrics; they do not occur alteration of the mechanical properties (resistance the traction and allonge) in the treated samples.
Doutorado
Ciencia e Tecnologia de Materiais
Doutor em Engenharia Química
Carvalho, José Geraldo de 1977. "Tratamentos térmico e corona em tecido de poliéster". [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/266853.
Texto completoDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química
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Resumo: O tratamento térmico, que na indústria têxtil é mais conhecido como termofixação, é um processo muito importante para garantir a estabilidade dimensional do tecido de poliéster durante os processos de beneficiamento e no uso. Mas o processo de termofixação modifica algumas propriedades do tecido e entre elas podemos destacar: Hidrofilidade, comportamento tintorial, alongamento e ruptura. Essas propriedades são influenciadas pelas variáveis tempo e temperatura de termofixação. Nesse sentido o presente trabalho tem como objetivo analisar as alterações proporcionadas pela termofixação nas propriedades físico-químicas do tecido de poliéster. O poliéster é um material que apresenta superfície quimicamente inerte, não porosa e com baixa energia de superfície (43 mN/m). O tratamento com descarga corona vem propor aumentar a energia de superfície, melhorar a hidrofilidade, o comportamento tintorial e a adesão do tecido termofixado e sem termofixar. Submeteram-se amostras de tecido plano de poliéster á termofixação em diversas combinações de tempo e temperatura dentro dos intervalos de 120 a 220°C e de 30 a 120 segundos. Após a termofixação mediu-se o encolhimento das amostras e submeteram-se as mesmas a testes de alongamento e ruptura. Trataram-se amostras de tecido de poliéster termofixadas e sem termofixar com descarga corona, e em seguida, submeteu-se as mesmas a testes de hidrofilidade, tingimento, estampagem, alongamento e ruptura. Observou-se que a termofixação promove encolhimento, aumento do alongamento, diminuição da hidrofilidade e da absorção de corante em tingimento de tecido de poliéster. O tratamento corona aumenta a hidrofilidade, a absorção de corante, a ancoragem de pigmentos em amostras de tecido de poliéster termofixadas e sem termofixar
Abstract: The thermal treatment, which in the textile industry is known as heat setting, is very important to ensure the dimensional stability of polyester fabric during the process of improving and use. But the process of heat setting changes some properties of the fabric and among them we can highlight: Hidrophilicity, dyeability, elongation and strength. These properties are influenced by variables dwell time and heat setting temperature. In that sense this work has as objective to analyze the changes caused by heat in the physico-chemical properties of polyester fabric. Polyester is a material that presents the surface chemically inert, non-porous and low surface energy (43 mN / m). The treatment with corona discharge is proposing to increase the surface energy, improve the hidrophilicity, dyeability and adhesion of the polyester fabric with and without heat setting. Samples of polyester plan fabric underwent to heat setting on various combinations of time and temperature within the interval between 120 to 220 ° C, from 30 to 120 seconds. After the heat setting was measured the shrinkage of the samples and underwent the samples by tests of elongation and rupture. Samples of polyester fabric with and without heat setting were treated with corona discharge and in sequence the samples were tested by hidrophilicity, dyeing and printing. The heat setting promotes shrinkage and increase the elongation of polyester fabric. It was observed that the heat setting promotes shrinkage, increase of elongation, reduction of hydrophilicity and reduction of uptake of dye in the dyeing of polyester fabric. The corona treatment increase the hydrophilicity, the absorption of dye in pad-thermofix process and the pigment anchoring in polyester fabric samples with and without heat setting
Mestrado
Ciencia e Tecnologia de Materiais
Mestre em Engenharia Química
Li, Jian-xing. "Coupling agent effects on the interfacial adhesion in a sheath/core type bicomponent fiber". Ohio : Ohio University, 1989. http://www.ohiolink.edu/etd/view.cgi?ohiou1182441608.
Texto completoGuerra, Juan Rafael Filgueira. "Projeto de antena de microfita flexível utilizando de tecido malha a base de fibras naturais e sintéticas". Universidade Federal Rural do Semi-Árido, 2016. http://bdtd.ufersa.edu.br:80/tede/handle/tede/715.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
The flexible microstrip antennas are devices that guarantee the development of communications systems with greater adaptability to the different types of microwaves applications .The possibility of an antenna be designed using textile materials facilitates their conditioning on systems that need is in contact or very close to the human body. The mesh fabric offers greater adaptability to the application due its flexibility. To build the antenna, is necessary check the compatibility between the knitted fabrics available and project needs. Therefore, is essential study the behavior of the electrical and physical features of each structure, analyzing also the influence of synthetic and organic fibers in performance. The characterization allows choice which fabrics is better to manufacture the antenna, is designed and built one microstrip antenna with classic rectangular geometry using the knitted fabric with better performance. The synthetic fibers have better physical characteristics that improve the adaptability of the tissue as a substrate. The electrical characteristics of the mesh fabrics they presented similar behavior as the frequency variation. In the frequency 2.45 GHz knitted fabric composed of polyester and spandex has the best actual values of relative permittivity and loss tangent thus constructed is used in the antenna design. The results show that the resonance frequency is approximately 2.68 GHz, a variation near 230 MHz, this is due to aspects of the test antenna construction
As antenas de microfitas flexíveis são dispositivos que garantem o desenvolvimento de sistemas de comunicações com maior adaptabilidade aos diversos tipos de aplicações em microondas. A possibilidade de uma antena ser projetada utilizando materiais têxteis facilita seu condicionamento em sistemas que necessitem estar em contato ou muito próximo ao corpo humano. O tecido de malha oferece maior adaptabilidade à aplicação devido a sua flexibilidade. Com o objetivo de construir a antena, é necessário verificar a compatibilidade entre os tecidos de malha disponíveis e as necessidades do projeto. Assim, é indispensável estudar o comportamento das características elétricas e físicas de cada estrutura. Analisando também, a influência das fibras sintéticas e orgânicas no desempenho. A partir da caracterização e escolha dos tecidos que comporão a antena, é projetada e construída uma antena de microfita com geometria retangular clássica utilizando o tecido com melhor desempenho. Os tecidos que contém fibras sintéticas apresentam características físicas que aumentam a adaptabilidade do tecido como substrato. As características elétricas dos tecidos apresentam comportamento semelhante quanto à variação da frequência. Na frequência de 2,45 GHz o tecido de malha composto por Poliéster e Elastano apresenta os melhores valores de permissividade relativa real e tangente de perdas, assim, é utilizado no projeto da antena construída. Os resultados demonstram que a frequência de ressonância é aproximadamente 2,68 GHz, representando uma variação aproxima de 230 MHz, isso ocorre devido a aspectos ligados a fase de construção da antena teste
2017-05-24
Sibellas, Aurélien. "Cordes textiles torsadées à fibres continues : Caractérisation de la structure et modélisation du comportement mécanique en extension". Thesis, Lyon, 2019. http://www.theses.fr/2019LYSEI017.
Texto completoTwisted continuous filament yarns are commonly used as reinforcements in a wide variety of industrial applications and more specifically as reinforcements in tyre rubber. The yarns concerned are made of nylon, polyester or aramid fibres by twisting them together (from 200 to 1000 fibres of the same material) to obtain what is called a single yarn. The assembly of two or three single yarns by twisting them together makes it possible to build a multiply yarn that will be called hybrid if the initial single yarns are made of different fibres. All configurations give a wide range of possible mechanical properties involving the effects of the material's behaviour, the local orientation of the fibres and the transverse pressures inducing an imbalance in the case of the presence of different types of fibres. This thesis presents a precise structural study of fiber orientations by X-ray microtomography of single and multiply yarns and an original tool to analyze the spatial frequencies characteristic of fiber trajectories. A mechanical model of single yarn in extension from the literature is enriched from this work supported by an additional experimental study of their lateral contraction under extension. The influence of the disorder of the initial fibre bundle on the mechanical behaviour of the final single yarns is analysed numerically by the finite element method by simulating the physical process taking place during twisting. Finally, a general mechanical model is proposed to predict the mechanical behaviour in extension of the hybrid multiply yarns, consisting of three single yarns showing different torsions
Léal, Françoise. "Etude de la production et de l'émanation de composés volatils malodorants sur textile à usage sportif". Thesis, Vandoeuvre-les-Nancy, INPL, 2011. http://www.theses.fr/2011INPL070N/document.
Texto completoFresh human sweat is odorless. Odoriferous volatile compounds are produced by the metabolism of bacteria living on the skin, generating strong malodor. Sweaty body odors do also appear on clothes during use, and especially on synthetic fabrics. The aim of this document is to improve understanding of odor emission by investigating subject effect, microbiota effect and fabric effect on the emission of odoriferous volatile compounds.Odors of perspiration are hereby globally approached with a wide use of methods and experimental devices, for microbial flora study as well as for odoriferous volatile compounds emission study.First, microflora enumeration has been simultaneously processed on the skin and on the fabric after exercise for 15 subjects. This experiment allowed an evaluation of the average bacterial transfer yield during physical activity and the beginning of the investigation of its effect on odor emission.A molecular biology methodology has then been developed in order to refine these results. Monitoring of qualitative composition of the microbiota has been performed to study the stability of the armpit’s ecosystem on a subject during 3 months. Specific microbial transfer from subject’s skin to clothe has been performed for 4 textile fabrics (including cotton and PET). This leaded to characterize the effect of specific bacterial transfer on odor emission from fabric.The last chapter is dedicated to the study of the emission of odoriferous volatile compounds over time using olfactory measurements and electronic nose for 8 selected fabrics. Principal component analysis targeted 9 chemical compounds that have been selected as malodorous behavior indicators for a given fabric. Those 9 compounds could be used for setting up a fitted physicochemical method of malodor.To conclude, this study helped to understand the effect of 3 factors in odor perception from a fabric after sport : subject, microbial flora and fabric. Perspectives have been charted on contact microbial contamination, but also on odor, and especially on desorption of odoriferous volatile molecules from a textile or knitted matrix. The solutions that could be used to limit malodorous emission from fabrics have also been discussed
Mmelesi, Olga Kelebogile. "Synthesis and characterization of pine cone carbon supported iron oxide catalyst for dye and phenol degradation". Thesis, Vaal University of Technology, 2017. http://hdl.handle.net/10352/418.
Texto completoFenton oxidation is classified into two processes, homogeneous and heterogeneous. Homogeneous Fenton oxidation process, have been shown to be efficient in the degradation of organic pollutants. However, it was shown to have limitations which can be addressed by the heterogeneous Fenton oxidation. Despite the high efficiency of the heterogeneous Fenton oxidation process in the degradation of recalcitrant organic pollutants, the currents synthesis trends of the heterogeneous Fenton catalyst have been proven to be time and energy constraining, since it involves the multi-step were the activated carbon have to be prepared first then co-precipitate the iron oxide on the activated carbon. However, as much as the heterogeneous Fenton catalyst has been proven to have high catalytic activity towards degradation of organic pollutants, these catalysts have some limitations, such limitations include metal ions being leached from the catalyst support into the treated water causing catalyst deactivation and a secondary pollution to the treated water. In this thesis, these catalysts have been applied in the degradation of recalcitrant organic pollutants such as methylene blue and phenols. This study focuses on the single step synthesis of iron oxide nanoparticles supported on activated carbon, were carbonaceous material is impregnated with iron salt then pyrolysed via microwave heating. Microwave power and the amount of iron salt were optimized. The prepared activated carbon-iron oxide composites were applied to the degradation of 2-nitrophenol (2-NP) and methylene blue (MB). Methylene blue was used as a model compound due to the fact that it is easier to monitor the degradation process with UV-Vis as compared to 2-nitrophenol . 2-nitrophenol the additional step for the adjustment of pH is required since nitrophenols are colorless in color at lower pH. The characterization showed that the microwave power and the amount of the iron precursor have an influence on the porosity and surface functional groups of the activated carbon. Further it was vi observed that microwave power and iron precursor influnces the amount of iron oxide formed on the surface of the support. It was also observed that the activated carbon-iron oxide composite have the catalytic effects on the Fenton oxidation process of MB and 2-NP. The parameters such as H2O2, pH, catalyst dose, initial concentration, temperature affect the degradation of both MB and 2-NP. Kinetics studies showed that Fenton is a surface driven reaction since the results fitted the pseudo first order model. The thermodynamics parameters also showed that the reaction is endothermic, spontaneous and is randomized. This implies that the reaction of the degradation of MB and 2-NP is feasible and the catalysts prepared have high catalytic activity. MB and 2-NP were degraded to smaller organic molecules (carboxylic acids). The stability of the catalyst observed to decrease as the number of cycles increased, this is due to the leaching of iron ions from the support material. Hence it was concluded that the activated carbon-iron oxide composite was successfully synthesized and had the high catalytic activity for the degradation of MB and 2-NP.
Beltran, Juan Felipe. "Computational modeling of synthetic-fiber ropes". Thesis, 2006. http://hdl.handle.net/2152/2678.
Texto completoBerry, Scott. "A characterization of micromanipulator controlled dry spinning of micro- and nanoscale polymer fibers". 2004. http://etd.louisville.edu/data/UofL0101t2004.pdf.
Texto completoReichard, Eric Jonathan. "Chemometrics applied to the discrimination of synthetic fibers by microspectrophotometry". 2014. http://hdl.handle.net/1805/3795.
Texto completoMicrospectrophotometry is a quick, accurate, and reproducible method to compare colored fibers for forensic purposes. The use of chemometric techniques applied to spectroscopic data can provide valuable discriminatory information especially when looking at a complex dataset. Differentiating a group of samples by employing chemometric analysis increases the evidential value of fiber comparisons by decreasing the probability of false association. The aims of this research were to (1) evaluate the chemometric procedure on a data set consisting of blue acrylic fibers and (2) accurately discriminate between yellow polyester fibers with the same dye composition but different dye loadings along with introducing a multivariate calibration approach to determine the dye concentration of fibers. In the first study, background subtracted and normalized visible spectra from eleven blue acrylic exemplars dyed with varying compositions of dyes were discriminated from one another using agglomerative hierarchical clustering (AHC), principal component analysis (PCA), and discriminant analysis (DA). AHC and PCA results agreed showing similar spectra clustering close to one another. DA analysis indicated a total classification accuracy of approximately 93% with only two of the eleven exemplars confused with one another. This was expected because two exemplars consisted of the same dye compositions. An external validation of the data set was performed and showed consistent results, which validated the model produced from the training set. In the second study, background subtracted and normalized visible spectra from ten yellow polyester exemplars dyed with different concentrations of the same dye ranging from 0.1-3.5% (w/w), were analyzed by the same techniques. Three classes of fibers with a classification accuracy of approximately 96% were found representing low, medium, and high dye loadings. Exemplars with similar dye loadings were able to be readily discriminated in some cases based on a classification accuracy of 90% or higher and a receiver operating characteristic area under the curve score of 0.9 or greater. Calibration curves based upon a proximity matrix of dye loadings between 0.1-0.75% (w/w) were developed that provided better accuracy and precision to that of a traditional approach.