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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

Proyecto de exportación de confecciones de tejido de punto con aplicaciones de textilería incaica como opción rentable de negocio con los Estados Unidos de América

Tinoco Tejeda, Martin Merardo January 2018 (has links)
El presente trabajo de investigación se desarrolló con la finalidad de ejercer la profesión de Administración de Negocios Globales, es por ello que se trabajó en las variables propuestas y su factibilidad en la ejecución en base a un estudio de mercado, un estudio organizacional sobre los aspectos legales y el cálculo de la inversión. El método de investigación utilizado fue el hipotético - deductivo y se aplicaron los diseños experimentales, longitudinales, prospectivos. Se consideró como muestra a 323 personas, todos de nacionalidad estadounidense. The present research work was developed in order to practice the profession of Global Business Administration, that is why we worked on the proposed variables and their feasibility in the execution based on a market study, an organizational study on the aspects legal and calculation of the investment. The research method used was the hypothetico - deductive and the experimental, longitudinal, prospective designs were applied. A sample of 323 people was considered, all of them of American nationality.
2

Estudo e desenvolvimento de antenas de microfita utilizando tecido de malha a base de fibras têxteis compostas / Study and development of microstrip antennas using knitted fabrics based on composite textile fibers

Holanda, Samanta Mesquita de 01 December 2016 (has links)
Submitted by Lara Oliveira (lara@ufersa.edu.br) on 2017-07-06T20:43:45Z No. of bitstreams: 1 SamantaMH_DISSERT.pdf: 5589913 bytes, checksum: 13f8ab4185b2d9b1c9576d1b7fd6d94b (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2017-07-18T15:04:50Z (GMT) No. of bitstreams: 1 SamantaMH_DISSERT.pdf: 5589913 bytes, checksum: 13f8ab4185b2d9b1c9576d1b7fd6d94b (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2017-07-18T15:05:35Z (GMT) No. of bitstreams: 1 SamantaMH_DISSERT.pdf: 5589913 bytes, checksum: 13f8ab4185b2d9b1c9576d1b7fd6d94b (MD5) / Made available in DSpace on 2017-07-18T15:05:42Z (GMT). No. of bitstreams: 1 SamantaMH_DISSERT.pdf: 5589913 bytes, checksum: 13f8ab4185b2d9b1c9576d1b7fd6d94b (MD5) Previous issue date: 2016-12-01 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The growing development of telecommunications, especially mobile devices, has intensified related searches the microstrip antennas in recent years since they have unique properties and wide range of applications. The constant demand for lighter and more flexible devices boosted research in wearable technology area where electronics are fully embedded in their fibers. In this context, knitted fabrics have the necessary elasticity to create adaptable and sports parts, enabling high mobility and comfort to its users. The textile antennas are malleable and, therefore, have great utility in applications where rigidity of traditional antennas is considered limiting, as in military use clothing and in the biomedical field. This work aims to study and develop microstrip antennas using knitted fabric based composite fibers, showing the procedures and materials used from the characterization and choice of fabrics to the design, manufacture and testing of the textile antenna. The electrical characterization was carried out using a Vector Network Analyzer (ARV) to obtain the electrical properties (permittivity and tangent losses). Obtaining textile properties (weight, dimensional stability, degree and tensile strength) was made in accordance with the technical standards, using the equipment available at the Department of Textile Engineering at the Federal University of Rio Grande do Norte (UFRN). The antenna has been designed using the transmission line model of Fortran program developed in accordance with the electrical properties of textile substrates. Subsequently the antenna was designed and simulated in HFSS® (High Frequency Structural Simulator), where radiation patterns are obtained, return loss, the Smith chart, current density and gain. The best simulated result was implemented with tissue disposed knitted in a three-layer structure according to the dimensions designed, and then the antenna is tested using a spectrum analyzer, which were collected data that allowed the manufacture of the letter Smith and graph of return loss. The experimental data were compared with the simulated and the results analyzed according to the literature that support this paper / O crescente desenvolvimento das telecomunicações, principalmente a de dispositivos móveis, têm intensificado as pesquisas relacionadas as antenas de microfita nos últimos anos, visto que estas possuem propriedades singulares, bem como vasta gama de aplicações. A constante procura por dispositivos mais leves e flexíveis impulsionou as pesquisas na área de tecnologia vestível, onde componentes eletrônicos são inteiramente embutidos em suas fibras têxteis. Nesse contexto, os tecidos malha possuem a elasticidade necessária para criar peças adaptáveis e esportivas, permitindo alta mobilidade e conforto aos seus usuários. As antenas têxteis são maleáveis e, por essa razão, têm grande utilidade em aplicações onde a rigidez das antenas tradicionais é considerada uma limitação, como em roupas de uso militar e na área biomédica. Este trabalho tem como objetivo estudar e desenvolver antenas de microfita utilizando tecido de malha à base de fibras têxteis compostas, mostrando os procedimentos e materiais utilizados desde a caracterização e escolha dos tecidos até o projeto, confecção e testes da antena têxtil. A caracterização elétrica foi realizada através de um Analisador de Redes Vetorial (ARV) para obtenção das propriedades elétricas (permissividade e tangente de perdas). A obtenção das propriedades têxteis (gramatura, estabilidade dimensional, titulação e resistência a tração) foi feita de acordo com as normas técnicas, utilizando os equipamentos disponíveis no Departamento de Engenharia Têxtil da Universidade Federal do Rio Grande do Norte (UFRN). A antena foi dimensionada através do modelo da linha de transmissão em programa desenvolvido na linguagem Fortran de acordo com as propriedades elétricas dos substratos têxteis. Posteriormente a antena foi desenhada e simulada no HFSS® (High Frequency Structural Simulator), onde serão obtidos os diagramas de radiação, perda de retorno, densidade de corrente e ganho. O melhor resultado simulado foi implementado com o tecido de malha disposto numa estrutura de três camadas de acordo com as dimensões projetadas e, em seguida, a antena foi testada através de um analisador de espectro, onde foram coletados dados que permitiram a confecção da carta de Smith e gráfico da perda de retorno. Os dados experimentais foram comparados com os simulados e, os resultados analisados de acordo com a literatura especializada que embasam este trabalho / 2017-07-06
3

Shielding effect to the flammable fibres offered by inherently flame retardant fibres

Khan, Jasra January 2019 (has links)
Flame retardant chemicals were used to make flammable fibres or fabrics flame retardant. Flame retardants protect the flammable material from fire by delaying or preventing the ignition process. The problem with flame retardants is unreliable durability when applied physically or bonded chemically on the surface of the fibre or fabric. This thesis project investigated the implementation of inherently flame retardant fibres as a shield form flame for flammable fibres. The most widely used flammable textiles fibres (cotton and polyester) were mixed with inherently flame retardant fibres (modacrylic and Lenzing FR) pairwise at fibre level for non-woven fabric and both fibre & yarn level for knitted fabric. The vertical flame test, where the fabric hung vertically and burned from the bottom, was used to characterise their burning behaviour. With the vertical flame test, it was found that flame shielding ability of inherently flame retardant fibres towards flammable fibres improves with an increasing proportion of inherently flame retardant fibres in the fabric. Also, fabric structure influences the shielding properties of the flame retardant fibres. A comparison between fibre and yarn level mixing for knitted fabric yarn level mixing was found to have better flame shielding properties. Thesis work points out the issue with flame retardant chemical and presents an alternative approach for conventional flame retardant.
4

Impact of Organic Solvent Treatments on Physical and Sensorial Properties of Knitted Fabrics.

Zamora Lagos, Sara Isabel January 2023 (has links)
Technologies that facilitate reusing and recycling printed textile products will contribute to achieving a circular textile industry. This project was done in collaboration with Vividye, a company developing a technology to create removable textile prints to be able to extend the lifespan of screen-printed textile products without affecting their quality. The technology involves several steps, including re-formulating printing paste and using a treatment to remove the print. This particular treatment consists of the use of different organic solvents. The aim of this project was to evaluate the effect of four organic solvent treatments, which are of interest to the company, on the physical and sensorial properties of conventional cotton (CO) and polyester (PET) knitted fabrics. Three cycles of the treatment were evaluated. Significant changes in yarn and fabric properties, such as tension and thickness, were found after the treatment, also for fabric sensorial properties, such as stiffness, softness, and smoothness. The behavior was different for each type of material which can be attributed to the affinity between the polymer and the solvent and the polymer, yarn, and fabric structure that facilitates the swelling. The properties assessed within this project can be related to the fabric's quality and feel. Therefore, it can be an essential factor in the user's preferences or influence the material's printability.
5

Élaboration de texticaments à visée antiinflammatoire contenant des microcapsules respectueuses de l’environnement / Elaboration of anti-inflammatory textiles based on eco-friendly microcapsules

Dao, Thi Chinh Thuy 08 February 2018 (has links)
L'utilisation des microcapsules fabriquées à partir de matériaux respectueux de l'environnement pour des applications textiles médicales a été étudiée et développée fortement au cours des dernières années. Le but de cette thèse est d'élaborer les textiles anti-inflammatoires à base de microcapsules respectueuses de l'environnement, utilisant trois types de matériaux textiles (coton, peco 65/35 et polyester) et cinq niveaux de longueur de boucle (2.81, 2.83, 2.87, 2,96 et 3,05 mm) sur étoffes tricotées à verrouillage de coton (nombre de fils Ne40). Les influences de la concentration en saponine, de la vitesse d'agitation au cours de l'étape d'émulsification et du volume d'éthyle acétate ajouté à la phase aqueuse sur les caractéristiques des microcapsules ont été étudiées. L'étude a également étudié les effets du rapport massique du coton et de la longueur de boucle des étoffes tricotées sur la distribution des microcapsules, la capacité de chargement des microcapsules et la capacité de libération de l'ibuprofène des étoffes tricotées traités par microcapsules. Les microcapsules d'Eudragit RSPO contenant de l'ibuprofène ont été élaborées par la technique d'évaporation de solvant, en utilisant le tensioactif bio-sourcé quillaja saponine et le solvant non halogéné d'éthyle acétate. Les microcapsules obtenues présentaient les formes sphériques avec un diamètre d (0,5) de 21,5 μm, approprié pour les applications textiles. Il a été trouvé que, pour empêcher la déformation des microcapsules pendant la traitement du textile, la séchage doit être effectuée sous vide à 45 ° C. Lorsque le rapport de teneur en fibres de coton dans le tissu augmentait, la distribution des microcapsules était moins régulière, ce qui entraînait un taux de libération plus faible de l'ibuprofène à partir des étoffes tricotées traités aux microcapsules. En outre, lorsque la longueur de la boucle augmente, la capacité de chargement des microcapsules des étoffes tricotées traités augmente, la distribution des microcapsules sur le tissu devient moins régulière et la vitesse de libération de l'ibuprofène des tissus traités aux microcapsules diminue. De plus, l'augmentation de l'extension du étoffes tricotées a favorisé la libération d'ibuprofène à partir des étoffes tricotées traités par les microcapsules à travers la peau de porc / The use of the microcapsules made from eco-friendly materials for medical textile applications has been researched and developed strongly in recent years. The aim of this thesis is to elaborate the anti-inflammatory textiles basing on eco-friendly microcapsules,using three kinds of textile materials (cotton, peco 65/35 and polyester)and five levels of the loop length (2.81, 2.83, 2.87, 2.96 and 3.05 mm) on the cotton interlock knitted fabrics (yarn count Ne40). The influences of the saponin concentration, the stirring rate during the emulsification step and the volume of ethyl acetate added to the aqueous phase on the characteristics of the microcapsules were studied. The influence of condition in drying on microcapsule’s morphology was also investigated.The thesis also researched the effects of cotton mass ratio and loop length of fabric on the microcapsule distribution, the microcapsule loading capability and the release capability of ibuprofen from the microcapsule treated fabrics. The Eudragit RSPO microcapsules containing ibuprofen were successfully elaborated by solvent evaporation technique, using the bio-sourced surfactant quillajasaponin and the non-halogenated solvent ethyl acetate. The obtained microcapsules exhibited the spherical shapes with d(0.5) diameter of 21.5 m, suitable for the textile applications. It was found that in order to keep the microcapsules from deformation during the textile finishing, the drying stage should be carried out in vacuum at 45oC. When the content ratio of cotton fibers in the fabric increased,the microcapsule distribution was less even, resulting in the lower release rate of ibuprofen from the microcapsule-treated fabrics. Besides, when the loop length increased, the microcapsule loading capability of the treated fabrics increased, the microcapsule distribution on the fabric became less even and the release rate of ibuprofen from the microcapsule-treated fabrics decreased. Furthermore, increasing the fabric extension favored the release of ibuprofen from the microcapsule-treated fabrics through the pigskin
6

Solblockerande textilier : Optimering av solskydd

Brobeck, Caroline, Westblom, Elin January 2018 (has links)
extilindustrin måste ständigt söka nya alternativ inom beläggningar och laminering för att minska den skadliga miljöpåverkan. En fråga som uppkommit är om beläggningar används i större utsträckning än vad som egentligen behövs. Denna kandidatuppsats har skrivits i samarbete med Artex AB och kretsar kring ett befintligt solskydd och solens ljusspektrum som består av strålar mellan 320–2500 nm. Material som bestrålas kan antingen absorbera, reflektera eller transmittera dessa strålar. Strålarnas alternativa vägar adderat med varandra blir alltid hundra procent, vilket innebär att genom att öka den reflekterande förmågan minskas de andra två tillstånden. I denna studie granskas den totala reflekterande förmågan av ljusspektrumet hos textila material som i sin tur beror på många olika faktorer. Det undersöks även om det är ett steg i fel riktning att använda sig av beläggningar för att nå ett bättre högreflekterande material. Detta även för att minska miljöbelastningen. Eftersom beläggningar generellt förstyvar material är detta kontraproduktivt när man vill bibehålla följsamheten hos en tygvara, vilket är avgörande för denna typ av produkt. Skrynkelheten går nämligen hand i hand med tygvarans då stumma yta. Detta projekt fokuserar på solskydd som ska användas inifrån en bil. Syftet med studien var alltså att undersöka om en obelagd vit och tät tygvara kan uppnå tillräcklig funktion för ett solskydd innanför en bil. I experimenten användes fyra olika tygvaror med olika strukturer i bindningarna för att göra en så omfattande studie som möjligt. Dessa fyra var: en satin, en varptrikå och två stycken tvåskaft, varav den ena glesare och mer matt än den andra. Respektive tygvara beströks med ett färgpigment för att analysera om kombinationen mellan reflektion och elastisk potential var möjlig. Tester som genomförts i denna undersökning var: bestämning av färghärdighet, total reflektion, ljustransmittansmätning och ett egenkomponerat skrynkeltest. Vidare granskades dess skillnader för att undersöka om ett vitt material kunde ge en bättre totalreflektion, men även för att bevisa att en tygvaras konstruktion kan erhålla följsamheten även om en beläggning är nödvändig. Mätvärdena granskades för att sedan jämföra, först med varandra och sedan mot ett referensprov som kommer från en befintlig produkt som författarna fick att tillgå från Artex AB. En trikåvaras elastiska förmåga visade sig kunna bibehållas trots ett belagt ytskikt, och visade även på bra totalreflektion. Denna varptrikå uppvisade, tillsammans med satinen, på bra totalreflektion då de var obelagda och hade god följsamhet. I test om totalreflektion visades det att en vit tät tygvara reflekterade större procent än en belagd tygvara i det synliga ljusets spektrum. För att kunna dra slutsatser om ett vitt obelagt tyg med dessa konstruktioner (satin och varptrikå) hade varit bättre för ett solskydd hade vidare undrsökningar behövts göras. Detta för att se hur mycket av den totala reaktionen som är diffus respektive spekulär / The textile industry must always find ways to reinvent itself and look for alternative options, as the coating and lamination industries are vital for a better environment. A question that needs answering is if coating on textiles are used more than needed. This bachelor thesis is written in cooperation with Artex AB and revolves around the suns light spectrum that consists of rays of 320 to 2500 nm. Materials that irradiate can either absorb, reflect or transmit these wavelengths. The rays alternative routes added with each other is always one hundred percent, which means that through increasing the reflecting capacity the other two will decrease. The most interesting part of this study, was to examine the ability of the light spectrum for material, and take in to consideration it’s construction, structure and color. Textile materials are often coated to add qualities and, in this case, to increase reflecting quality. This study is trying to prove, that it's a step in the wrong direction when it comes to the functionality of a sunshade product and for a reduced impact on the environment. As coating generally stiffens materials it’s contuerproductive with regards to keeping the resilience for the fabric, which is decisive for this type of product. The wrinkles go hand in hand with the fabrics coated surface. Since this project focuses on an existing sunshade product that will be used inside of a car, the heat radiation and the undulations within a certain wavelength that requires reflection will be focused on. The purpose with the study was to examine if an uncoated white fabric can achieve the same function in a sunshade as the current fabric in the product. In the experiments, four fabrics with different structures were used to complete such a comprehensive study as possible. These four fabrics were: one satin, one warp knitted and two plain weave, where one of them was more faint and sparse than the other. Each fabric was coated with a color pigment to analyze the possibilities of a high reflective material that still has elastic potential. The tests that were made was: determination of color fastness, total reflection, light transmit and a wrinkle test. Further on these differences were reviewed, and then concluded that the coating, in hope of increasing the reflection, is negligible. But also, to prove that a fabrics construction can keep its resilience even with a coated surface. These values have been reviewed and then compared with each other and against a reference fabric that the writers took part of from Artex AB. A warp knitted fabric was able to maintain its elastic ability regardless of a coated surface, and also shows good total reflection. This warp knitted fabric showed, together with the satin, good total reflection when they were uncoated and had good resilience. In this test for total reflection, it was proven that a white dense fabric reflects better than a coated fabric in the visible spectra of light. To be able to conclude if a white uncoated fabric with these constructions (satin and warp knitting) would be more useful for a sunshade, further studies had to be made, to see how much of the total reaction that is diffuse and specular.
7

Komponenty na bázi vlnovodu integrovaného do textilu / Textile Integrated Waveguide Components

Cupal, Miroslav January 2020 (has links)
Práce je zaměřena na výzkum struktur založených na vlnovodu integrovaném do textilu (TIW). Pozornost je věnována elektrické charakterizaci textilních materiálů (textilní substráty, nitě), které jsou využívány při implementaci antén, rekonfigurovatelných a aktivních obvodů integrovaných do textilu. Práce se zabývá návrhem vícevrstvých přechodů mezi mikropáskovým vedením na konvenčním substrátu a vedeními integrovanými do textilu. Dále je prezentován koncept přepínače integrovaného do textilu. Přepínač je řízen vodivými sloupky, které vytvářejí otevřenou či zavřenou stěnu prostřednictvím stejnosměrně ovládaných PIN diod. Na závěr je formulována metodika návrhu kruhově polarizovaných antén integrovaných do textilu, jež jsou určeny pro práci v ISM pásmech až do 24 GHz. Všechny postupy návrhu byly ověřeny simulacemi a měřeními reálných vzorků, které byly vyrobeny sítotiskem stříbrnou polymerovou pastou. Polovodičové komponenty byly k obvodům přilepeny vodivým stříbrným lepidlem. Komponenty vyrobené sítotiskem byly porovnávány s referenčními strukturami, které byly realizovány pomocí samolepicí měděné fólie.

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