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Mikrovlákna na bázi polyhydroxybutyrátu pro medicínské aplikace / Microfibers based on polyhydroxybutyrate for medical applicationsGregušková, Zuzana January 2021 (has links)
Diplomová práca je zameraná na mikrovlákna na báze biopolyméru poly(3-hydroxybutyrátu) a ich využitie v medicínskych aplikáciách. Teoretická časť práce sa zaoberá štúdiom procesu tvorby vláken pomocou technológie odstredivého zvlákňovania, jeho kinetikou a faktormi ovplyvňujúcimi vznik a vlastnosti vláken. Teoretická časť sa následne orientuje na krátky prehľad biopolymérov používaných v tejto technológii, charakteristiku materiálu poly(3-hydroxybutyrátu) a taktiež prezentuje návrh potenciálnej cieľovej aplikácie daných mikrovláken. Praktická časť sa koncentruje sa prípravu mikrovláken zo spomínaného poly(3-hydroxybutyrátu). Sledované a optimalizované sú viaceré parametre vedúce k lepšej zvlákniteľnosti materiálu. Praktická časť je rozšírená o modifikáciu polymérneho roztoku prídavkom iných biopolymérov a zmäkčovadiel a prípravu mikrovláken z takto modifikovanej polymérnej zmesi. Pozornosť je venovaná taktiež optimalizácii procesných parametrov. Pripravené mikrovlákna sú následne analyzované a charakterizované viacerými metódami a vzájomne porovnávané s cieľom vyvinúť alternatívu k súčasne používaným substrátom pre rast buniek v 3D.
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Investigation of the binding effect of fungal fiber (grown on apple pomace) in the formation of lyocell nonwoven textiles and their potential applicationsLuo, Xue January 2021 (has links)
This project combines nonwoven technology, biological technology and food waste management and seeks for this feasibility to use fungal microfiber (FM) as a binder for lyocell pro-duction and the characterizations for possible applications. Rhizopus delemar was cultivated apple pomace in liquid-state fermentation to obtain mycelia biomass. The biomass was later blended in a kitchen blender for one minute. The blended FM was later mixed with 6 mm lyocell fibre at different FM dry weight percentage and water to make nonwoven webs by wet-laid method. The feasibility of using fungal microfiber as a binder for lyocell nonwovens was confirmed in this study. It is not possible to make nonwoven webs using lyocell short fibre without any binder applied. With 5%_FM, the tensile strength of lyocell nonwoven webs reached 0.0989 MPa. A clear increasing tensile strength was recorded as the increasing of FM weight per-centage and resulted a highest tensile strength at 9.38 MPa when applying 60%_FM. The re-sult of water contact angle proved that the increasing FM could decrease the hydrophobicity of nonwoven samples. Abrasion test showed that FM could improve the abrasion resistance of the lyocell nonwoven samples. Porosity test showed that lyocell nonwoven samples with a higher FM ended up with smaller mean flow pore size diameter (MFP) that nonwoven samples with 65%_FM has an average MFP at 7.26 m m. The SEM images reviled that FM bonded nonwoven webs had a fibrous structure, which is due to binding effect of fungal microfiber on lyocell short fibers. These characterizations have demonstrated the mechanism of using fungal microfiber as a binder for lyocell nonwovens in this project. In this thesis project, FM bonded lyocell nonwoven webs showed a great potential on the application of nonwoven applications such as interior materials or filtration materials.
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A Study on the Extrusion of Soy Protein Film Incorporated with Soy-Derived Cellulose FibersChan, Roc Tsz-Pang 06 September 2012 (has links)
A biodegradable alternative to synthetic plastics was explored in this study through the extrusion of a soy-based protein/fiber composite film.
Two fractions of fibers with different size distributions (nano- to micro-) were isolated from soy pods and stems using a chemi-mechanical method. Fibers through successive treatments were characterized via microscopy, x-ray diffraction, and Fourier Transform infrared analysis (FTIR).
The continuous extrusion of homogenous SPI film (0.08 to 0.3 mm thick) was reported for the first time. Processing window was limited by protein sensitivity to moisture and heat. With the incorporation of extracted fibers, homogenous films were obtained with a concentration below 0.5% w/w fiber/SPI. Increasing fiber content resulted in the formation of aggregates. At the optimal concentration of 0.25% w/w fiber/SPI, films exhibited mild improvements in mechanical performance most noticeable at a high RH (84%). Film properties with and without fiber addition were negatively affected by relative humidity. Titanium dioxide addition suggested mild coupling effects for SPI and fiber. / Hannam Soy Foundation / Ontario Ministry of Agricultural, Food, and Rural Affairs (OMAFRA)
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Separation of microfibers from laundry waste water by hydrocyclone : In cooperation with Electrolux ProfessionalLorentzon, Anna Cecilia Carolina January 2021 (has links)
Microfibers, textile fibres shorter than 5 mm, and are shed from fabrics during wear and released into the laundry effluent during washing. When passed through the wastewater treatment plant (WWTP), they adsorb toxins, heavy metals and pathogens before being released into the environment. Synthetic microfibers persist for long periods of time in aquatic environments and very little is known about the degradation of processed natural fibres. Hydrocyclonic separation was studied as a way to separate the microfibers from the effluent before being they get additionally contaminated at the WWTP. A hydrocyclone has no moving parts and functions by utilizing centrifugal force and the difference in specific gravity between the fluid and the particles that are to be separated. The separation efficiency is dependent on its dimensional and operation parameters. No previous studies on hydrocyclonic separation of microfibres were found. Polyester fleece blankets were washed. The effluent was filtered, and the filters weighed to determine the mass of the separated fibres. Sampling of the inhomogeneous effluent presented a challenge and larger sample volumes would be needed to adequately represent the population. Using a Büchner funnel, filter fouling led to filtration times of up to 6 h for 1 l of effluent. Dividing the 1 l samples into two 0.5 l samples, filtering separately and adding the weight reduced filtration time to 2 h and the results were not significantly different from filtering the whole 1 l sample with one filter. The hydrocyclones tested separated around 11% of the total weight of microfibers in the effluent, too low to be deemed viable. As only a few dimensional variables were tested, it could possible that a higher fraction could be separated with this method. Given that the commercially available filtration systems separate 30-80%, refining existing methods may yield better results.
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Core-shell hydrogel microfiber-expanded pluripotent stem cell-derived lung progenitors applicable to lung reconstruction in vivo / コアシェル型ハイドロゲルマイクロファイバーを用いた多能性幹細胞由来肺前駆細胞の拡大培養および生体内における肺再構築への応用Ikeo, Satoshi 24 January 2022 (has links)
京都大学 / 新制・課程博士 / 博士(医学) / 甲第23602号 / 医博第4789号 / 新制||医||1055(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 長船 健二, 教授 川口 義弥, 教授 大森 孝一 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
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Preparation of films and nonwoven composites from fungal microfibers grown in bread wasteKöhnlein, Maximilian January 2020 (has links)
Unsold bread makes up a signification fraction of waste occurring in Swedish supermarkets. This thesis seeks to address the problem of food waste, by cultivating filamentous fungi on bread waste and producing chitinous films and nonwovens from them. Rhizopus delemar was cultivated on bread waste in liquid-state fermentation in order to obtain mycelia biomass. The biomass was processed by alkali or protease treatments to disrupt the fungal cells and remove proteins and fats. Afterwards it was subjected to a bleaching treatment to remove lignin fractions of bread residues. The treated biomass was then subjected to a grinding treatment for a homogeneous dispersion of mycelial fibers, where the dispersion was confirmed by microscopic images. The chemically and mechanically processed biomass was used for the preparation of films and nonwoven composites by employing a wet-laid papermaking process. The films exhibited plastic-like features, due to their brittleness and their smooth upper surface. Films and nonwoven composites were characterized on their tensile properties, surface water contact angle and their surface morphology by scanning electron microscopy. Treating fungal biomass by alkali and then bleaching resulted in films with atensile modulus of 3.38 GPa and an ultimate tensile strength of 71.50 MPa. These are the highest reported tensile properties for mycelia derived films to date. Water contact angle measurements confirmed a hydrophobic quality of mycelial films. Scanning electron microscopy showed a very dense and even surface without an obvious fibrous morphology. Fungal biomass and viscose fibers together form a rigid nonwoven composite, in which fungal biomass takes over the role of a natural eco-friendly binding matrix. Flexural rigidity measurements were out of bounds and need to be confirmed by future studies. Additionally, a second strain of fungi, Fusarium venenatum, was cultivated on bread particles in water suspension in order to determine optimum growth conditions for future scale-up investigations.
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Matrices tridimensionnelles pour la régénération osseuse / Three-dimensional matrices for bone regenerationTerranova, Lisa 25 January 2017 (has links)
L’architecture des biomatériaux de comblement osseux à un réel impact sur l’activité cellulaire, la vascularisation et la diffusion de facteurs de croissance. Dans un premier temps, différentes membranes de polystyrène (PS) composées de fibres alignées ou aléatoires ont été étudiées. Elles sont non biodégradables et pourraient servir de supports pour la régénération de larges défauts osseux. Nous avons montré la cytocompatibilité in vitro des membranes en analysant l’adhésion, la prolifération et la différenciation cellulaire. Ensuite, des membranes de PS ont été enrichies de grains de β-TCP ou de nanoparticules d’or. Nous les avons implantées dans un modèle de défaut crânien de taille critique chez la souris. L’addition de β-TCP a stimulé la repousse osseuse grâce à la grande bioactivité des céramiques. Les membranes ont été biotolérées, les fibres ont été encapsulées dans l’os néoformé mais également dans un tissu conjonctif dense. Les nanoparticules d’or immobilisées sur des fibres ont migré dans l’os ou ont été phagocytées. Dans un second temps, différentes formulations de granules poreux de β-TCP ont été analysées par nanotomographie aux rayons X. L’architecture macroporeuse des granules varie inversement avec la concentration en β-TCP. Les faces internes montrent une grande hétérogénéité de minéralisation. Pour mimer les conditions d’utilisation en chirurgie maxillo-faciale, les granules ont été empilés dans des tubes. Nous avons montré que l’architecture des empilements de granules dépendait de leur forme. L’empilement de granules commerciaux (contenant12,5g de β-TCP) mime l’architecture naturelle et les propriétés physiques de l’os. / The architecture of bone filling biomaterials has a real impact on cellular activity, vascularization and diffusion of growth factors. As a first step, different polystyrene (PS) scaffolds composed of aligned or random fibers were studied. They were non-biodegradable and could be used as supports for regeneration of large bone defects. We showed the in vitro cytocompatibility of the scaffolds by analyzing cell adhesion, proliferation and differentiation. Then, polystyrene scaffolds were enriched with β-TCP grains or gold nanoparticles. We implanted them in a model of critical size defect in mouse calvaria. Addition of β-TCP stimulated bone regrowth due to the high bioactivity of the ceramics. Scaffolds were biotolerated, fibers were encapsulated in the newly formed bone and also in a dense connective tissue. The gold nanoparticles immobilized on fibers migrated into the bone or were phagocytized. As a second step, different formulations of porous granules of β-TCP were analyzed by X-ray nanotomography. The macroporous architecture of granules varies inversely with the concentration of β-TCP. The internal faces howed a great heterogeneity of mineralization. Tomimic the conditions in maxillofacial surgery, granules were stacked in tubes. We have shown that the architecture of the granules depends on their shape.The stacks of commercial granules (containing 12.5 g ofβ-TCP) mimicked the natural architecture and physical properties of bone.
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Evaluación comparativa de las propiedades plasticas y mecanicas del concreto F’C 210 kg/cm2 reforzado con microfibras sinteticas de polipropileno de 20 y 30mm en losas de viviendas expuestas a altas temperaturas en Ucayali / omparative evaluation of the plastic and mechanical properties of concrete f'c 210 kg / cm2 reinforced with 20 and 30mm synthetic polypropylene microfibers in housing slabs exposed to high temperatures in ucayaliCcasani Caballero, Jean Frank Aurelio, Eduardo Carrascal, Carlos Sebastian 24 May 2021 (has links)
La presente investigación se basa en el estudio de la influencia de microfibras sintéticas de polipropileno en las propiedades mecánicas y plásticas de losas de concreto f’c=210 kg/cm2 expuestas a altas temperaturas en el departamento de Ucayali. Para ello, se procedió a realizar mezclas de concreto con dos microfibras de polipropileno de 20 y 30 milímetros de longitud, a su vez, dichas mezclas fueron dosificadas con 600, 900 y 1200 g/m3 de concreto y evaluarlas respecto a contracción platica, resistencia a compresión y flexión residual. El primer ensayo, se realizó en base a la Norma ASTM C-1579 (Método de prueba estándar para evaluar el agrietamiento por contracción plástica del hormigón reforzado con fibra restringida), evaluando losas de concreto de 560x355x100 mm. sometidas a temperaturas mayores a 27°C y velocidades de viento de 8 km/h y compararlas entre la muestra patrón y muestras reforzadas con microfibras; obteniéndose una Relación de Reducción de Grietas (CRR) máxima de 68.50% para el concreto con fibra de 300 mm. y una dosificación de 1200 g/m3. Para el ensayo de compresión, guiado por la NTP 339.034 – ASTM-C39 (Método de ensayo normalizado para la determinación de la resistencia a la compresión del concreto, en muestras cilíndricas) se ensayaron probetas de 6x12 pulgadas para cada longitud de y dosificación de microfibra para compararlas respecto a la mezcla convencional; para el concreto con microfibra de 30 mm se obtuvo un incremento promedio de 8% para una dosificación de 1200 gr/m3 para un tiempo de curado de 28 días, por otro lado, la de 20 mm alcanzo incrementos máximos de 7% para la misma dosificación y tiempo de curado que el anterior. Para el último ensayo, se basó de la Norma ASTM C 1399 (Método de ensayo para determinar el esfuerzo residual promedio del concreto reforzado con fibra), en la cual se evaluaron muestras prismáticas de 100x100x350 mm sometiéndolas a cargas para obtener cual es la tensión residual que soportan a diferentes deformaciones para cada tipo de microfibras y dosificaciones. El concreto reforzado con microfibra sintética de 30 mm, obtuvo mayores valores de tensiones residuales (1.95 MPa para 1200 gr/m3) para todas las dosificaciones estudiadas en comparación a la de 20 mm. (1.86 MPa 1200 gr/m3). Al finalizar la experimentación, se concluyó que la microfibra sintética de polipropileno de 30 mm tuvo mejor desenvolvimiento que la de 20 mm para los 3 ensayos realizados. Además, se observó una relación directa entre el aumento de las propiedades mecánicas y plásticas con la cantidad de dosificación incorporada al concreto. / This research is based on the study of the influence of synthetic polypropylene microfibers on the mechanical and plastic properties of concrete slabs f’c = 210 kg / cm2 exposed to high temperatures in Ucayali. For this, concrete mixtures with two microfibers of 20 and 30 millimeters in length were made, in turn, dosages of 600, 900 and 1200 g / m3 of concrete were included and evaluated for plastic contraction, compressive strength and residual flexion. The first test was carried out on the basis of ASTM C-1579 (Standard test method to evaluate cracking by plastic contraction of reinforced fiber reinforced concrete), evaluating concrete slabs of 560x355x100 mm subjected to temperatures greater than 27 ° C and wind speeds of 8 km / h and compare them between standard samples and reinforced with microfibers; obtaining maximum Crack Reduction Ratio (CRR) of 68.50% for concrete with 300 mm fiber. and a dosage of 1200 g / m3. For the compression test, guided by Standard NTP 339.034 - ASTM-C39 (Standard test method for the determination of the compressive strength of concrete, in cylindrical samples) 6x12 inch specimens were tested for each microfiber and dosing to compare them with respect to the conventional mixture; for concrete with 30 mm microfiber an average increase of 8% was obtained for a dosage of 1200 gr / m3 for a curing time of 28 days, on the other hand, the 20 mm reached maximum increases of 7% for the same dosage and cure time than the previous one. For the last test, it was based on ASTM C 1399 (Test method to determine the average residual stress of fiber reinforced concrete), in which prismatic samples of 100x100x350 mm were evaluated by subjecting them to loads to obtain what the residual tension is that support different deformations for each type of microfibers and dosages. The reinforced concrete with synthetic microfiber of 30 mm, obtained higher values of residual stresses (1.95 MPa for 1200 gr / m3) for all the dosages studied in comparison to that of 20 mm. (1.86 MPa 1200 gr / m3). At the end of the experimentation, it was concluded that the 30 mm polypropylene synthetic microfiber had a better performance than the 20 mm microfiber for the 3 tests performed. In addition, a direct relationship was observed between the increase in mechanical and plastic properties with the amount of dosage incorporated into the concrete. / Tesis
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Empleo de textiles en aplicaciones de absorción sonoraSegura Alcaraz, María del Pilar 21 January 2021 (has links)
[ES] Esta memoria de tesis presenta una contribución al estudio de los materiales textiles en el campo de la absorción sonora. En concreto, se ha trabajado con la asociación de una capa absorbente fibrosa constituida por una estructura laminar no tejida cuya composición es poliéster y una capa resistiva a base de tejido de calada también compuesta de poliéster. El objetivo de este trabajo consiste en evaluar las variaciones que provocan los cambios en distintos parámetros de construcción de la capa resistiva, sobre el comportamiento del conjunto ante el sonido. Para abordar el problema se emplean distintos tejidos de calada, tales como telas simples, múltiples, acolchadas y rizo, con diferentes parámetros de construcción. Se mide el coeficiente de absorción de sonido al aplicarlas a diferentes espesores de estructura no tejida de poliéster, empleando el tubo de ondas estacionarias. Tras analizar los resultados obtenidos, se observan diferencias en los coeficientes de absorción de sonido alcanzados, las cuales se explican atendiendo al espesor del no tejido, pero también se observa la influencia de las características constructivas de los tejidos empleados. Finalmente, se emplea el diseño de experimentos para obtener la combinación óptima de parámetros que proporciona el mayor coeficiente de absorción de sonido para un tipo de tejido dado en todas las frecuencias estudiadas. Se concluye que, la modificación en la absorción de sonido de una estructura no tejida al aplicar una capa resistiva de tejido de calada, es lo suficientemente significativa como para ser tenida en cuenta a la hora de diseñar productos textiles para acondicionamiento acústico y que el diseño de experimentos constituye una herramienta de gran utilidad a este fin. / [CAT] Aquesta memòria de tesi presenta una contribució a l'estudi dels materials tèxtils en el camp de l'absorció sonora. En concret, s'hi ha treballat amb l'associació d'una capa absorbent fibrosa constituïda per un no teixit de polièster i una capa resistiva a base de teixit de calada de composició polièster. L'objectiu d'aquest treball consisteix a avaluar les variacions que provoquen els canvis en diferents paràmetres de construcció de la capa resistiva, sobre el comportament del conjunt davant el so. Per a abordar el problema s'empren diferents teixits de calada, com ara teles simples, múltiples, encoixinats i ris, amb diferents paràmetres de construcció. Es mesura el coeficient d'absorció en aplicarles a diferents grossàries de no teixit de polièster, emprant el tub d'ones estacionàries. S'observen diferències en els coeficients d'absorció de so obtinguts, les quals s'expliquen atenent la grossària del no teixit, però també a les característiques constructives dels teixits emprats. Finalment, s'empra el disseny d'experiments per a obtenir la combinació òptima de paràmetres que proporciona el major coeficient d'absorció de so per a un tipus de teixit donat en totes les freqüències estudiades. Es conclou que la modificació en l'absorció de so d'un no teixit en aplicar una capa resistiva de teixit de calada és prou significativa per a ser tinguda en compte a l'hora de dissenyar productes tèxtils per a condicionament acústic i que el disseny d'experiments constitueix una eina de gran utilitat a aquest efecte. / [EN] This thesis report presents a contribution to the study of textile materials in the field of sound absorption. Specifically, we have worked with the association of a fibrous absorbent layer consisting of a polyester nonwoven and a resistive layer based on openwork fabric. The objective of this work is to evaluate the variations that cause the changes in different construction parameters of the resistive layer, on the behaviour of the whole before the sound. To address the problem, different openwork fabrics are used, such as single, multiple, quilted and curl fabrics, with different construction parameters. The absorption coefficient is measured when applied to different thicknesses of polyester nonwoven, using the standing wave tube. Differences are observed in the sound absorption coefficients obtained, which are explained according to the thickness of the nonwoven, but also to the constructive characteristics of the fabrics used. Finally, the design of experiments is used to obtain the optimal combination of parameters that provides the highest sound absorption coefficient for a given type of tissue at all frequencies studied. It is concluded that the modification in the sound absorption of a nonwoven when applying a resistive layer of openwork fabric is significant enough to be taken into account when designing textual products for acoustic conditioning and that the design of experiments constitutes a very useful tool for this purpose. / Al departamento de Ingeniería Textil y Papelera y a la unidad docente de Alcoy del departamento de Mecánica de los Medios Continuos y Teoría de Estructuras, por facilitarme los medios necesarios para realizar todas las actividades que han sido necesarias. A Jaime Ramis Soriano, por recibirme en el laboratorio de Grupo de Acústica Aplicada del IUFACyT de la Universidad de Alicante. / Segura Alcaraz, MDP. (2020). Empleo de textiles en aplicaciones de absorción sonora [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/159786 / TESIS
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