Academic literature on the topic 'Fibers'
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Journal articles on the topic "Fibers"
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Parasakthibala, Ms G., and Mrs A. S. Monisha. "A Review on Natural Fibers; Its Properties and Application Over Synthetic Fibers." International Journal for Research in Applied Science and Engineering Technology 10, no. 8 (August 31, 2022): 1894–97. http://dx.doi.org/10.22214/ijraset.2022.46530.
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Abstract: Fibre is a long, thin strand or thread of material made by weaving or knitting threads together. Fibre is a hair like strand of material. A fibre is the smallest visible unit of any textile product. Fibres are flexible and may be spun into yarn and made into fabric. Natural fibres are taken from animals, vegetables or mineral sources. A few examples of widely used natural fibres include animal fibre such as wool and silk vegetables fibres, especially cotton and flax and asbestos, a mineral. Natural fibers are more important part in our human environment. Natural fibers are ecofriendly and inexpensive which are readily available in nature. In this chapter we discuss about the overview of natural fiber and their characteristic. this paper also deals with the impact of natural fibers over the synthetic fibers and also the application of natural fiber in various fields.
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Kumar,, Ravikant, and Rahul Sharma. "A Comparative Study of the Use of Concrete Mix Using Jute Fibers." International Journal for Research in Applied Science and Engineering Technology 10, no. 5 (May 31, 2022): 511–15. http://dx.doi.org/10.22214/ijraset.2022.42207.
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Abstract: The character of fiber reinforced concrete can be changed by the variation of certain factors. these factors are the geometric configuration of fibers, type and. quantity of fibers, , dispersal, direction, and concentration of the fibres Portland cement concrete is assumed to be a relatively. Brittle material .When non-reinforced concrete is exposed to tensile stresses. This is likely to fracture and fail. Since the start of the nineteenth century, studies were conducted. to reinforce concrete by using fibres. After the reinforcement of concrete by fibers, it becomes a composite group in which the fibres endures the tensile stresses. When concrete is reinforced by. using fiber in the mixture, it further increases the tensile strength of the composite system. Research has revealed that. The strength of concrete may be improved greatly by the adding of fibers Keywords: Fiber, jute fibres, NDT Mix design, design mix
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Zhou, Rong, and Ming Xia Yang. "Research on Mechanical Properties of Several New Regenerated Cellulose Fibers." Advanced Materials Research 332-334 (September 2011): 489–95. http://dx.doi.org/10.4028/www.scientific.net/amr.332-334.489.
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Regenerated cellulose fiber is the most widely-used and most variety of cellulose fiber. Five categories and ten kinds of fibers such as lyocell fiber, modal fiber, bamboo pulp fiber, sheng-bast fiber, Outlast viscose fiber were chosen as the research object. The strength property and elasticity of fibers in dry and wet state were tested and analysis. The comprehensive performances of fabrics were studied and mechanical properties of the fibers were listed in the order from good to bad by grey clustering analysis. The results show lyocell G100 and lyocell LF have better comprehensive mechanical properties ,while other new regenerated cellulose fibers’ comprehensive mechanical properties are general. Among these fibers modal fiber’s comprehensive mechanical properties are slightly better than sheng-bast fibers’ and bamboo pulp fibers’. Modal fiber, sheng-bast fiber and Bamboo pulp fiber have no significantly poor single parameter and all of them have better comprehensive mechanical properties than various viscose fibers. Outlast viscose in which has been added phase change materials sensitive to temperature by Microcapsule techniques fundamentally keeps similar comprehensive mechanical properties with other regenerated cellulose fibers,but its properties decline slightly .
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BORISADE, Sunday Gbenga, Isiaka Oluwole OLADELE, Oyetunji AKINLABI, Abdullahi Olawale ADEBAYO, and Olaoluwa Abraham OLUWASANMI. "IMPACT OF ALKALINE TREATMENT ON THE CONSTITUENTS, STRENGTH AND MORPHOLOGICAL CHARACTERISTICS OF BANANA FIBER." European Journal of Materials Science and Engineering 8, no. 2 (June 20, 2023): 102–7. http://dx.doi.org/10.36868/ejmse.2023.08.02.102.
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The readily availability of natural fibers have made them to be less expensive compared to the synthetic fibers. Hence, highest substitute for synthetic fibers in composites development today is natural fibers. In this research, banana fiber was extracted by dew retting and treated with alkaline for surface modification and possibly strengthening. Both treated and untreated fibers were tested with universal tensile testing machine and examined their surface morphology with scanning electron microscopy. The banana fiber's ultimate tensile strength (UTS) was assessed as a function of fiber diameter, test length and testing speed. It was observed from the results that chemical treatment improved the tensile strength of the fiber while surface morphology was noticed to be rough due to the removal of some fiber constituents. Hence, it was discovered that alkaline treatment improved the fiber condition, thus, making the fiber a suitable substitute for synthetic fibers in composite development
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Palanikumar, K., Elango Natarajan, Kalaimani Markandan, Chun Kit Ang, and Gérald Franz. "Targeted Pre-Treatment of Hemp Fibers and the Effect on Mechanical Properties of Polymer Composites." Fibers 11, no. 5 (May 9, 2023): 43. http://dx.doi.org/10.3390/fib11050043.
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Research on plant-fiber-reinforced composites has gained significant research interest since it generates composites with exceptional mechanical properties; however, the potential of hemp fibers can only be fully exploited if the fibers are well separated from the bundle to achieve cellulose-rich fibers. This is because well-separated bast fibers that are long and exhibit higher fiber aspect ratio enhance the mechanical properties of the composite by influencing property translations upon loading. A key feature for successful implementation of natural fibers is to selectively remove non-cellulosic components of hemp fiber to yield cellulose-rich fibers with minimal defects. Targeted pre-treatment techniques have been commonly used to address the aforementioned concerns by optimizing properties on the fiber’s surface. This in turn improves interfacial bonding between the fibers and the hydrophobic polymer, enhances the robustness of hemp fibers by improving their thermal stability and increases resistance to microbial degradation. In this study, we comprehensively review the targeted pre-treatment techniques of hemp fiber and the effect of hemp fiber as a reinforcement on the mechanical properties of polymeric composites.
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Manshor, R. M., Hazleen Anuar, Wan Busu Wan Nazri, and M. I. Ahmad Fitrie. "Preparation and Characterization of Physical Properties of Durian Skin Fibers Biocomposite." Advanced Materials Research 576 (October 2012): 212–15. http://dx.doi.org/10.4028/www.scientific.net/amr.576.212.
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Durian skin fibres (DSF) are cellulose-based fibres extracted from the durian peel. This paper present the physical behaviour, chemical structure and crystallinity of the fibres, as observed by environmental scanning electron microscope (ESEM), Fourier transform infrared (FTIR) and X-ray diffraction (XRD). The characteristic of the natural fibers produces from durian skins are similar with other types of natural fiber. The average diameter and density are 0.299 mm and 1.243 g/cm3, respectively while the crystallinity index is slightly higher than the common fibers. The properties and charecteristic of durian skin fibers are within the propertise of lignocellulosic fiber which is suitable for development of biocomposite materials.
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Zhang, Wei, Xu Wang, and Hong Wei Xing. "Numerical Simulation of the Cooling Process of the Blast Furnace Slag Fiber." Advanced Materials Research 934 (May 2014): 223–29. http://dx.doi.org/10.4028/www.scientific.net/amr.934.223.
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The cooling process of the blast furnace slag fibers was simulated and calculated by the numerical simulation software. The different length-diameter ratio fibers for 100:1 and 1000:1 were chosen and the temperature fields of the fibers cooling process under the different conditions were analyzed. The results showed that the single fiber’s solidification has begun at 0.1s, the fiber forms the whole shell on its surface at 0.9s, and the center of the fiber become solid at about 1.5s. Multi-fibers cooling process is different from the single fiber and the solidification time obviously become longer. 3-fibers’ solidification performs began at about 0.1s, and the whole solidification process needs about 5s.
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Angel, Allen, and Kathryn A. Jakes. "Preparation And elemental analysis of ancient fibers." Proceedings, annual meeting, Electron Microscopy Society of America 45 (August 1987): 410–11. http://dx.doi.org/10.1017/s0424820100126846.
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Fabrics recovered from archaeological sites often are so badly degraded that fiber identification based on physical morphology is difficult. Although diagenetic changes may be viewed as destructive to factors necessary for the discernment of fiber information, changes occurring during any stage of a fiber's lifetime leave a record within the fiber's chemical and physical structure. These alterations may offer valuable clues to understanding the conditions of the fiber's growth, fiber preparation and fabric processing technology and conditions of burial or long term storage (1).Energy dispersive spectrometry has been reported to be suitable for determination of mordant treatment on historic fibers (2,3) and has been used to characterize metal wrapping of combination yarns (4,5). In this study, a technique is developed which provides fractured cross sections of fibers for x-ray analysis and elemental mapping. In addition, backscattered electron imaging (BSI) and energy dispersive x-ray microanalysis (EDS) are utilized to correlate elements to their distribution in fibers.
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Reddy, K. Tharun Kumar, and Srikanth Koniki. "Mechanical properties of concrete reinforced with graded pva fibers." E3S Web of Conferences 309 (2021): 01177. http://dx.doi.org/10.1051/e3sconf/202130901177.
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Concrete is poor in tensile property due to its brittle nature. Improvement in the mechanical properties of concrete is carried by combining the rebars and fibers in concrete. Earlier research state that non-metallic fibres improve pre-crack performance and metallic fibers improve post crack performance. Short fibers resist the micro-cracks at an early stage and long fibers resist macro-cracks. The combination of short and long fibers makes the performance of concrete much effective. In this study, the investigation is done on non-metallic PVA fiber with the lengths of 6mm (Short fiber) and 12mm (Long fiber) by hybridization of fibers on 50MPa concrete. The investigation is done in two stages; in the first stage, the optimum dosage of fiber content and strength effectiveness of strengths is carried. Further, in the second stage the hybridization of fiber is done with the 30% SF + 70% LF, 50%SF + 50% LF, 70% SF + 30% LF for finding the optimum hybrid combination. Mechanical properties of concrete like flexural strength, split tensile strength, compressive strength is investigated. The results obtained by the hybridization of fibers are compared with the mono fiber performance and control mix. Improvement in strength parameters is observed in fiber hybridization. According to the fiber functionality, the hybrid combination of 30% SF + 70% LF showed desired results by improving the overall performance of concrete. More long fibers content improves the crack growth resistance than short fibers in concrete.
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Liu, Xue-Yan, Yu Ye, Ke Li, and Yun-Qi Wang. "Stress Path Efforts on Palm Fiber Reinforcement of Clay in Geotechnical Engineering." Water 15, no. 23 (November 22, 2023): 4053. http://dx.doi.org/10.3390/w15234053.
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Sixteen Reduced Triaxial Compression (RTC) triaxial tests were conducted to investigate the reinforcement effect of fibered clay in this paper. Palm fiber with four different fiber lengths (5 mm, 10 mm, 15 mm, and 20 mm) and four different fiber contents (0.3%, 0.5%, 0.7%, and 0.9% in mass) were utilized. Accordingly, three additional groups of triaxial tests were performed to analyze the stress path effects with four different stress paths, including RTC, Conventional Triaxial Compression (CTC), Reduced Triaxial Extension (RTE), and isotropic Triaxial Compression (TC). Three samples were tested, including fibered clay with a fiber length of 10 mm and a fiber content of 0.7% (referred to as 10 mm 0.7%), fibered clay with a fiber length of 20 mm and a fiber content of 0.5% (referred to as 20 mm 0.5%), and bare clay, which was used to reveal the fiber reinforcement of clay. All samples were tested under consolidated undrained conditions. The test results showed that in RTC conditions, the deviator stress increased to a greater extent with 0.3% mass content of fibers according to the same higher confining pressures of bare clay. Fibers primarily increased the cohesion of fibered clay, a shear strength parameter, in terms of total stress, whereas they also increased the friction angle of fibered clay in terms of effective stress. For short fibers, the coefficient of strength reinforcement of the fibered clay increased with fiber content. However, for long fibers, this reinforcement may lead to a weakening of the clay’s strength, as the long fibers may cluster or weaken along their longitude. Among the four stress paths (CTC, TC, RTC, and RTE) examined, the reinforcement took effort mainly in the CTC condition. In contrast, in unloading conditions, the fibers had little contribution to reinforcement. Consequently, in unloading conditions, such as deep excavating and slope cutting, the stress path should be considered to obtain a reliable parameter for geotechnical engineering applications.
Dissertations / Theses on the topic "Fibers"
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Santos, Eliane Moura dos. "Processos relacionados a inserção de fluidos para sensoriamento com fibras de cristal fotônico." [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/278251.
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Orientadores: Luiz Carlos Barbosa, Cristiano Monteiro de Barros CordeiroDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin
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Resumo: Este trabalho apresenta estudos de como inserir fluidos (líquidos e gases) em fibras ópticas microestruturadas, especialmente fibras de cristal fotônico, também conhecidas como PCF¿s (do inglês Photonic Crystal Fibers). Estas fibras possuem buracos de ar que percorrem todo seu comprimento. Elas podem ser divididas em dois grandes grupos: as de núcleo sólido que guiam luz por reflexão interna total e as de núcleo oco que guiam luz por um mecanismo conhecido como photonic bandgap. Ambos os tipos de fibras permitem várias aplicações em áreas como óptica e fotônica e nos dedicamos aqui à área de sensoriamento a fibra. Nesta área, usamos os microburacos para inserir fluido e dessa maneira manipular as propriedades de guiamento (em fibras de núcleo líquido), deixar a fibra mais sensível a algum parâmetro externo ou para sensoriar o fluido em questão. Nos três casos, precisamos estudar os processos de preenchimentos de fibras microestruturadas. Para este fim, estudamos e desenvolvemos maneiras de inserir fluidos em fibras de núcleos sólidos ou ocos. Usando preenchimento seletivo, produzimos fibras com núcleo líquido, criando uma região de alta interação entre luz e material. Neste trabalho, estudamos diferentes técnicas de preenchimento. A primeira, para fibras de núcleo líquido, é um preenchimento seletivo que pode ser feito usando uma máquina de emendas (splicer) ou um polímero para bloquear os microburacos. O outro consiste em manter as pontas das fibras livres (para medidas ópticas) enquanto o preenchimento é feito. Por fim, usamos o conhecimento desses processos em aplicações como sensoriamento de fluidos ou parâmetros externos e manipulação de propriedades de guiamento da luz
Abstract: This work presents studies of how to insert fluids (liquid and gas) into microstructured optical fibers, especially photonic crystal fibers, also known as PCF¿s. These optical fibers possess air holes that run along its entire length. They can be divided into two major groups: solid core fibers that guide light by total internal reflection and hollow core fibers that guide light by photonic bandgap. Both types of fibers allow several applications in areas such as optics and photonics and we dedicated this work to the fiber-sensing field. In this area we use the micro holes to insert fluids and in this way to manipulate the guidance properties in liquid core fibers, to leave the fiber more sensitive to some external parameter or to sensing the fluid. In these three cases we need to study the filling procedures in microstructured fibers. For this purpose, we studied and developed ways of inserting fluids in hollow and solid core fibers. We produced liquid core fibers, creating a high light-material overlap, using a selective filling technique. In this work we studied different filling techniques. The first one, for liquid core fibers, is a selective filling, which can be done by using a splicer machine or a polymer to block the fiber micro holes. The last one consists of keeping the fiber tips free (for optical measurements) while the filling is done. And finally we used the filling process knowledge in applications like sensing of fluids or external parameters and manipulation of guidance properties
Mestrado
Física Geral
Mestre em Física
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MURA, EMANUELE. "PHOPSHATE OPTICAL FIBERS FOR IR FIBER LASERS." Doctoral thesis, Politecnico di Torino, 2014. http://hdl.handle.net/11583/2544536.
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Paye, Corey. "An Analysis of W-fibers and W-type Fiber Polarizers." Thesis, Virginia Tech, 2001. http://hdl.handle.net/10919/32474.
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Optical fibers provide the means for transmitting large amounts of data from one
place to another and are used in high precision sensors. It is important to have a good
understanding of the fundamental properties of these devices to continue to improve their
applications.
A specially type of optical fiber known as a W-fiber has some desirable properties
and unique characteristics not found in matched-cladding fibers. A properly designed W-
fiber supports a fundamental mode with a finite cutoff wavelength. At discrete
wavelengths longer than cutoff, the fundamental mode experiences large amounts of loss.
The mechanism for loss can be described in terms of interaction between the fiberâ ¢s
supermodes and the lossy interface at the fiberâ ¢s surface. Experiments and computer
simulations support this model of W-fibers.
The property of a finite cutoff wavelength can be used to develop various fiber
devices. Under consideration here is the fiber polarizer. The fiber polarizer produces an
output that is linearly polarized along one of the fiberâ ¢s principal axes. Some of the
polarizer properties can be understood from the study of W-fibers.Master of Science
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Washburn, Brian Richard. "Dispersion and nonlinearities associated with supercontinuum generation in microstructure fibers." Diss., Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/30964.
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Polley, Arup. "High performance multimode fiber systems a comprehensive approach /." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/31699.
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Thesis (Ph.D)--Electrical and Computer Engineering, Georgia Institute of Technology, 2009.Committee Chair: Ralph, Stephen; Committee Member: Barry, John; Committee Member: Chang, G. K.; Committee Member: Cressler, John D.; Committee Member: Trebino. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Rugeland, Patrik. "Applications of monolithic fiber interferometers and actively controlled fibers." Doctoral thesis, KTH, Laserfysik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-118750.
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The objective of this thesis was to develop applications of monolithic fiber devices and actively controlled fibers. A special twin-core fiber known as a ‘Gemini’ fiber was used to construct equal arm-length fiber interferometers, impervious to temperature and mechanical perturbations. A broadband add/drop multiplexer was constructed by inscribing fiber Bragg gratings in the arms of a Gemini Mach-Zehnder interferometer. A broadband interferometric nanosecond switch was constructed from a micro-structured Gemini fiber with incorporated metal electrodes. Additionally, a Michelson fiber interferometer was built from an asymmetric twin-core fiber and used as a high-temperature sensor. While the device could be readily used to measure temperatures below 300 °C, an annealing process was required to extend the range up to 700 °C. The work included development, construction and evaluation of the components along with numerical simulations to estimate their behaviors and to understand the underlying processes. The thesis also explored the use of electrically controlled fibers for filtering in the microwave domain. An ultra-narrow phase-shifted fiber Bragg grating inscribed in a fiber with internal electrodes was used as a scanning filter to measure modulation frequencies applied to an optical carrier. A similar grating was used inside a dual-wavelength fiber laser cavity, to generated tunable microwave beat frequencies. The studied monolithic fiber interferometers and actively controlled fibers provide excellent building blocks in such varied field as in microwave photonics, telecommunications, sensors, and high-speed switching, and will allow for further applications in the future.Syftet med denna avhandling var att utveckla tillämpningar av monolitiska fiber komponenter samt aktivt kontrollerbara fiber. En speciell tvillingkärnefiber, även kallad ’Geminifiber’ användes för att konstruera fiber interferometrar med identisk armlängd som ej påverkas av termiska och mekaniska variationer. En bredbanding utbytarmultiplexor konstruerades genom att skriva in fiber Bragg gitter inuti grenarna på en Gemini Mach-Zehnder interferometer. Geminifibrer med interna metallelektroder användes för att konstruera en bredbandig nanosekundsnabb interferometrisk fiberomkopplare. Därtill användes en tvillingkärnefiber som en hög-temperatursensor. Även om komponenten direkt kan användas upp till 300 °C, måste den värmebehandlas för att kunna användas upp till 700 °C. Arbetet har innefattat utveckling, konstruktion och utvärdering av komponenterna parallellt med numeriska simuleringar för att analysera deras beteenden samt få insikt om de underliggande fysikaliska processerna. Avhandlingen behandlar även tillämpningar av en elektriskt styrbar fiber för att filtrera radiofrekvenser. Ett ultrasmalt fasskiftat fiber Bragg gitter skrevs in i en fiber med interna elektroder och användes som ett svepande filter för att mäta modulationsfrekvensen på en optisk bärfrekvens. Ett liknande gitter användes inuti en laserkavitet för att generera två olika våglängder samtidigt. Dessa två våglängder användes sedan för att generera en svävningsfrekvens i mikrovågsbandet. De undersökta monolitiska fiberinterferometrarna och de aktivt styrbara fibrerna erbjuder en utmärkt byggsten inom så pass skiljda områden som Mikrovågsfotonik, Telekommunikation, Sensorer samt Höghastighets-omkopplare och bör kunna användas inom många olika tillämpningar i framtiden.
QC 20130226
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Kominsky, Daniel. "Development of Random Hole Optical Fiber and Crucible Technique Optical Fibers." Diss., Virginia Tech, 2005. http://hdl.handle.net/10919/28949.
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This dissertation reports the development of two new categories of optical fibers. These are the Random Hole Optical Fiber (RHOF) and the Crucible Technique Hybrid Fiber (CTF). The RHOF is a new class of microstructure fiber which possesses air holes which vary in diameter and location along the length of the fiber. Unlike all prior microstructure fibers, these RHOF do not have continuous air holes which extend throughout the fiber. The CTF is a method for incorporating glasses with vastly differing thermal properties into a single optical fiber. Each of these two classes of fiber brings a new set of optical characteristics into being. The RHOF exhibit many of the same guidance properties as the previously researched microstructure fibers, such as reduced mode counts in a large area core. CTF fibers show great promise for integrating core materials with extremely high levels of nonlinearity or gain. The initial goal of this work was to combine the two techniques to form a fiber with exceedingly high efficiency of nonlinear interactions.
Numerous methods have been endeavored in the attempt to achieve the fabrication of the RHOF. Some of the methods include the use of sol-gel glass, microbubbles, various silica powders, and silica powders with the incorporation of gas producing agents. Through careful balancing of the competing forces of surface tension and internal pressure it has been possible to produce an optical fiber which guides light successfully.
The optical loss of these fibers depends strongly on the geometrical arrangement of the air holes. Fibers with a higher number of smaller holes possess a markedly lower attenuation. RHOF also possess, to at least some degree the reduced mode number which has been extensively reported in the past for ordered hole fibers. Remarkably, the RHOF are also inherently pressure sensitive. When force is applied to an RHOF either isotropically, or on an axis perpendicular to the length of the fiber, a wavelength dependent loss is observed. This loss does not come with a corresponding response to temperature, rendering the RHOF highly anomalous in the area of fiber optic sensing techniques. Furthermore an ordered hole fiber was also tested to determine that this was not merely a hitherto undisclosed property of all microstructure fibers.
Crucible technique fibers have also been fabricated by constructing an extremely thick walled silica tube, which is sealed at the bottom. A piece of the glass that is desired for the core (such as Lead Indium Phosphate) is inserted into the hole which is in the center of the tube. The preform is then drawn on an fiber draw tower, resulting in a fiber with a core consisting of a material which has a coefficient of thermal expansion (CTE) or a melting temperature (Tm) which is not commonly compatible with those of silica.Ph. D.
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Richmond, Eric William. "Birefringent single-arm fiber optic enthalpimeter for catalytic reaction monitoring." Diss., This resource online, 1990. http://scholar.lib.vt.edu/theses/available/etd-07282008-135248/.
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Acera, Fernandez José. "Modification of flax fibres for the development of epoxy-based biocomposites : Role of cell wall components and surface treatments on the microstructure and mechanical properties." Thesis, Montpellier, 2015. http://www.theses.fr/2015MONTS218.
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Les fibres végétales peuvent être considérées comme une alternative intéressante aux fibres de verre pour la fabrication de matériaux composites. En effet, elles présentent des caractéristiques physiques intéressantes, telles que leur faible densité et leurs bonnes propriétés mécaniques spécifiques, qui peuvent rivaliser avec les composites renforcés de fibres de verre. En outre, les fibres végétales sont obtenues à partir de ressources renouvelables, et présentent généralement moins d'impacts environnementaux lors de leurs phases de production, d’utilisation et en fin de vie. Contrairement aux fibres de verre, les fibres végétales, telles que des fibres de lin, présentent des structures hiérarchiques complexes composées essentiellement de cellulose, hémicellulose, lignine, ciments peptiques et extractibles lipophiliques (cires, acides gras, etc.). Cette composition varie selon les espèces, le lieu et les conditions de croissance, la maturité de la plante, etc. De la même façon, la composition biochimique et la structure des produits et des sous-produits issus du lin sont soumis à de grandes variations selon les étapes successives de transformation réalisées à partir des tiges de lin jusqu’aux fils et tissus. Cela influence fortement les propriétés finales des fibres de lin et de leurs biocomposites. La première partie de cette étude se concentre sur la caractérisation de fibres de lin au cours de leurs étapes successives de transformation. Une homogénéisation de la composition chimique est observée dans les étapes finales de transformation, ainsi qu’une augmentation des propriétés en traction longitudinale des mèches de fibres de lin. La deuxième partie traite de l'utilisation de différents traitements de lavage appliqués sur des tissus d’étoupes de lin et leur influence sur l'extraction des composants de la paroi cellulaire des fibres, ainsi que sur la microstructure et les propriétés mécaniques de biocomposites époxy/lin. Il est montré que les composants de la paroi cellulaire jouent un rôle clé dans la dispersion des mèches et des fibres élémentaires de lin et sur le comportement mécanique transversal de leurs biocomposites. Enfin, l'application de différents traitements de fonctionnalisation sur des tissus de fibre de lin est étudiée afin d'améliorer l'adhérence interfaciale entre les fibres et la matrice. L'utilisation de molécules de type organosilanes (aminosilane, époxysilanes) et de molécules biosourcés (acides aminés et polysaccharides) est étudiée. Une augmentation de la rigidité en traction longitudinale et de la rigidité et de la contrainte maximale en traction transverse est observée en raison de l'amélioration de l'adhésion interfaciale par la fonctionnalisation de surface des fibres avec des molécules d'origine biosourcé et non-biosourcéNatural fibres can be considered as a relevant alternative to glass fibres in the manufacture of composite materials. Indeed, they present interesting physical characteristics, such as low density and good specific mechanical properties, which can compete with glass fibre reinforced composites. Moreover, natural fibres are obtained from renewable resources, and generally present lower environmental impacts during their production and use phases and their end of life. Unlike glass fibres, natural fibres, such as flax fibres, are complex hierarchical materials composed essentially of cellulose, hemicellulose, lignin, peptics cements and lipophilic extractives (waxes, fatty acids, etc.). This composition varies among species, collection site, plant maturity, batches, etc. Besides, the biochemical composition and structure of flax products and sub-products undergo wide variations according to the transformation steps from stems to yarns and fabrics. This influences greatly the final properties of flax fibres and their biocomposites. The first part of this study is focused on the characterization of flax fibres during their successive transformation steps. A homogenization of the chemical composition is observed at the final transformation steps, as well as an increment of the longitudinal tensile properties of flax yarns. The second part deals with the use of different washing treatments applied on flax tow fabrics and their influence on the extraction of flax cell wall components and the resulting microstructure and mechanical properties of epoxy/flax fibres reinforced biocomposites. It is shown that cell wall components play a key role in the flax yarns and elementary fibres dispersion and transverse mechanical behaviour of biocomposites. Finally, the application of different functionalization treatments onto flax fibres fabrics is investigated in order to improve the interfacial adhesion between fibres and matrix. The use of non-bio-based organosilane molecules (aminosilane, epoxysilane) and bio-based molecules (amino-acids and polysaccharides) is studied. Improvedstiffness in longitudinal tension test and stiffness and tensile strength in transverse tension test are observed due to the improvement of interfacial adhesion by surface functionalization of the fibres with both bio-based and non-bio-based molecules
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Osório, Jonas Henrique 1989. "Specialty optical fibers for sensing = Fibras ópticas especiais para sensoriamento." [s.n.], 2017. http://repositorio.unicamp.br/jspui/handle/REPOSIP/330348.
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Orientador: Cristiano Monteiro de Barros CordeiroTese (doutorado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin
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Resumo: Nesta tese, fibras ópticas especiais são estudadas para fins de sensoriamento. Primei-ramente, propomos a estrutura denominada fibra capilar com núcleo embutido (embedded-core capillary fibers) para realização de sensoriamento de pressão. Estudos numéricos e analíticos foram realizados e mostraram que altas sensibilidades a variações de pressão poderiam ser al-cançadas com esta estrutura simplificada, que consiste de um capilar dotado de um núcleo, dopado com germânio, em sua parede. Experimentos permitiram medir uma sensibilidade de (1.04 ± 0.01) nm/bar, que é um valor alto quando comparado a outros sensores de pressão ba-seados em fibras microestruturadas. Ademais, estudamos fibras do tipo surface-core, que são fibras cujos núcleos são colocados na superfície externa da fibra. Nesta abordagem, redes de Bragg foram utilizadas para obter sensores de índice de refração ¿ fazendo-se uso da interação entre o campo evanescente do modo guiado no núcleo e o ambiente externo à fibra ¿ e de cur-vatura ¿ ao se explorar o fato de que, nestas fibras, o núcleo se encontra fora do centro geomé-trico da mesma. As sensibilidades a variações de índice de refração e curvatura medidas, 40 nm/RIU em torno de 1.41 e 202 pm/m-1 comparam-se bem a outros sensores baseados em redes de Bragg. Outrossim, fibras capilares poliméricas foram investigadas como sensores de temperatura e pressão. Para a descrição do sensor de temperatura, usou-se um modelo analítico para simular o espectro de transmissão dos capilares e a sua dependência com as variações de temperatura. No que tange à aplicação de sensoriamento de pressão, variações nas espessuras dos capilares devido à ação da pressão foram calculadas e relacionadas à sensibilidade da me-dida de monitoramento. Nestas duas aplicações, realizações experimentais também são repor-tadas. Finalmente, oportunidades adicionais de sensoriamento ao se utilizar fibras ópticas es-peciais são apresentadas, a saber, um sensor de pressão para dois ambientes baseados em fibras de cristal fotônico, um sensor de três parâmetros baseado em redes de Bragg, fibras afinadas e interferência multimodal, um sensor de nível de líquido baseado em redes de Bragg e interfe-rência multimodal e um sensor de temperatura baseado em fibras embedded-core preenchidas com índio. Os resultados aqui reportados demonstram o potencial das fibras ópticas em forne-cerem plataformas de sensoriamento para alcançar medidas de diferentes tipos de parâmetros com alta sensibilidade e resolução adequada
Abstract: In this thesis, specialty optical fibers for sensing applications are investigating. Firstly, we propose the embedded-core capillary fiber structure for acting as a pressure sensor. Analyt-ical and numerical studies were performed and showed that high pressure sensitivity could be achieved with this simplified fiber structure, which consists of a capillary structure with a germanium-doped core placed within the capillary wall. Experiments allowed measuring a sensitivity of (1.04 ± 0.01) nm/bar, which is high when compared to other microstructured optical fiber-based pressure sensors. Moreover, we studied the so-called surface-core optical fibers, which are fibers whose cores are placed at the external boundary of the fiber. In this approach, Bragg gratings were used to obtain refractive index ¿ making use of the interaction between the guided mode evanescent field and the external medium ¿ and directional curva-ture sensors ¿ by exploring the off-center core position. The measured refractive index and the curvature sensitivities, respectively 40 nm/RIU around 1.41 and 202 pm/m-1, compares well to other fiber Bragg grating-based sensors. Additionally, antiresonant polymer capillary fibers were investigated as temperature and pressure sensors. For the temperature sensing descrip-tion, one used an analytical model to simulate the transmission spectra of such fibers and the dependence on temperature variations. Regarding the pressure sensing application, pressure-induced capillary wall thickness variations were analytically accounted and related to the sys-tem pressure sensitivity. In both these applications, experimental data were presented. Finally, additional opportunities using specialty optical fibers were presented, namely, a photonic-crystal fiber-based dual-environment pressure sensor, a three parameters sensor using Bragg gratings, tapered fibers and multimode interference, a liquid-level sensor based on Bragg grat-ings and multimode interference, and a temperature sensor based in an embedded-core fiber filled with indium. The results reported herein demonstrates the potential of optical fibers for providing sensing platforms to attain measurements of different sort of parameters with highly sensitivity and improved resolutions
Doutorado
Física
Doutor em Ciências
152993/2013-4
CNPQ
Books on the topic "Fibers"
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Ilvessalo-Pfäffli, Marja-Sisko. Fiber atlas: Identification of papermaking fibers. Berlin: Springer-Verlag, 1994.
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Veit, Dieter. Fibers. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-15309-9.
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Knapp, Brian J. Fibers. Henley-on-Thames: Atlantic Europe, 2003.
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Calvin, Woodings, and Textile Institute (Manchester England), eds. Regenerated cellulose fibres. Boca Raton, FL: CRC Press, 2001.
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K, Mohanty Amar, Misra Manjusri, and Druzal Lawrence T, eds. Natural fibers, biopolymers, and biocomposites. Boca Raton, FL: CRC Press, 2005.
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Alexis, Méndez, and Morse T. F, eds. Specialty optical fibers handbook. Amsterdam: Academic Press, 2007.
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Shelton, Linda C. Manmade fibers. Washington, DC: Office of Industries, U.S. International Trade Commission, 1995.
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Shelton, Linda C. Manmade fibers. Washington, DC: Office of Industries, U.S. International Trade Commission, 1995.
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Shelton, Linda C. Manmade fibers. Washington, DC: Office of Industries, U.S. International Trade Commission, 1995.
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National Institute of Research on Jute & Allied Fibre Technology (India). Perspective plan, 1995-2020. Calcutta: National Institute of Research on Jute & Allied Fibre Technology, Indian Council of Agricultural Research, 1997.
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Laurikainen, Pekka, Sarianna Palola, Amaia De La Calle, Cristina Elizetxea, Sonia García-Arrieta, and Essi Sarlin. "Fiber Resizing, Compounding and Validation." In Systemic Circular Economy Solutions for Fiber Reinforced Composites, 125–40. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-22352-5_7.
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AbstractThe mechanical performance of a composite is greatly related to the load transfer capability of the interface between the matrix and the reinforcing fibers, i.e. the fiber/matrix adhesion, which is enhanced by a surface treatment called sizing. The original sizing of reinforcing fibers is removed during recycling process, which is recognized to contribute in typical issues of recycled fibers, namely uneven fiber properties and poor fiber/matrix adhesion. Applying a new sizing, a process denoted here as resizing, can help mitigate the issues. Furthermore, the sizing has a major role in improving the processability of the fibers as it contributes to the distribution of the fibers in the matrix. Proper distribution, along with the fiber fraction, are highly important for the composite performance. These properties are ensured by proper compounding. Here we demonstrate and validate the process steps to resize and compound recycled glass and carbon fibers with thermoplastic matrices. We found that at a relatively high sizing concentration, the compounding of all tested material combinations was possible. The resizing of the recycled fibers improved the compatibility at the fiber/matrix interface. It was concluded that recycled fibers can be used to replace virgin fibers in automotive industry to allow weight reductions and to promote circularity.
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García-Arrieta, Sonia, Essi Sarlin, Amaia De La Calle, Antonello Dimiccoli, Laura Saviano, and Cristina Elizetxea. "Thermal Demanufacturing Processes for Long Fibers Recovery." In Systemic Circular Economy Solutions for Fiber Reinforced Composites, 81–97. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-22352-5_5.
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AbstractThe possibility of recycling glass (GF) and carbon fibers (CF) from fiber-reinforced composites by using pyrolysis was studied. Different fibers from composite waste were recovered with thermal treatment. The recycled fibers were evaluated as a reinforcement for new materials or applications. The main objective was to evaluate the fibers obtained from the different types of industrial composite waste considering the format obtained, the cleanliness and the amount of inorganic fillers and finally, the fibers quality. These characteristics defined the processes, sectors and applications in which recycled fibers can replace virgin fibers. These fibers were also evaluated and validated with tensile testing and compared to the tensile strength of virgin GF and CF.
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Veit, Dieter. "Fruit Fibers." In Fibers, 263–72. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-15309-9_8.
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Veit, Dieter. "Polylactic Acid." In Fibers, 739–48. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-15309-9_35.
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Veit, Dieter. "Man-Made Fibers: Polymer Formation Processes." In Fibers, 413–29. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-15309-9_14.
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Veit, Dieter. "Test Methods." In Fibers, 959–73. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-15309-9_47.
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Veit, Dieter. "Biopolymers." In Fibers, 883–902. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-15309-9_42.
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Veit, Dieter. "History." In Fibers, 9–39. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-15309-9_2.
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Veit, Dieter. "Polyolefins." In Fibers, 693–720. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-15309-9_33.
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Veit, Dieter. "Processes for the Production of Textile Filament Yarns." In Fibers, 513–19. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-15309-9_19.
Full textConference papers on the topic "Fibers"
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Ramkumar, S. "Shear Behaviour of Fiber Reinforced Concrete Beams Using Steel and Polypropylene Fiber." In Sustainable Materials and Smart Practices. Materials Research Forum LLC, 2022. http://dx.doi.org/10.21741/9781644901953-21.
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Abstract. The experimental study provides a series of tests for characterizing the structural behavior of fibre reinforced concrete beams subjected to shear loads. The paper involves usage of 2 types of fibers - polypropylene and steel fiber. The work suggests that the shear cracking resistance of the materials used are significantly improved by the fibers. The fibers reduced the crack width to about one quarter of the width in the shear-reinforced girders. Reliance on steel fibres increases the ductility of concrete. Adding steel fibres to concrete improves its post-tensile cracking behaviour. Shear strength is increased with the increase in fiber aspect ratio and fiber volume fraction. The concrete beams are casted for the size of 150 mm x 250 mm x 2100 mm. The behavior of fiber reinforced concrete beams for the addition of 0.4 percentage of fibers in both PFRC and SFRC under loading condition were observed and the load carrying capacity was increased compared to reinforced concrete.
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Haggans, C. W., H. Singh, W. F. Varner, and J. S. Wang. "Analysis of Narrow Depressed-Cladding Fibers for Minimization of Cladding and Radiation Mode Losses in Fiber Bragg Gratings." In Bragg Gratings, Photosensitivity, and Poling in Glass Fibers and Waveguides. Washington, D.C.: Optica Publishing Group, 1997. http://dx.doi.org/10.1364/bgppf.1997.bmg.11.
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Undesirable losses in highly reflective fiber Bragg gratings due to coupling to bound cladding modes or lossy radiation modes are well documented1-5. Several approaches have been proposed for reducing this coupling, including high LP01 mode confinement fibers (high numerical aperture single-mode fibers6 and two-mode fibers7), fibers with equally photosensitive core and cladding regions8, and, recently, fibers with wide depressed cladding regions5. However, the solution detailed by Komukai, et al.6 is undesirable due to mode-field mismatch losses when splicing to conventional single-mode telecommunication fibers operated at 1550 nm (e.g, Corning SMF-28) and the solution of Okude, et al.7 requires advanced fabrication techniques. Additionally, while the solutions detailed by Dong, et al.5 and Delevaque, et al.8 reduce cladding mode losses for gratings with no variation of the photoinduced index transverse to the fiber axis, it is well known that strong asymmetries in the transverse photoinduced index profile can occur in Type I9 and Type II10 gratings due to the sidewriting process. In fact, elaborate writing schemes have been proposed to reduce this asymmetry11-12. Additionally, in practice, small tilts of the grating fringe planes can be introduced during fabrication due to mask-fiber misalignment. It is demonstrated in this paper that the solutions detailed by Dong, et al.5 and Delevaque, et al.8 are not optimum for azimuthally asymmetric transverse photoinduced index distributions, and a new narrow depressed cladding fiber design that has superior loss suppression characteristics for moderate grating asymmetries is presented.
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Pohl, Alexandre A. P., Roberson A. Oliveira, Kevin Cook, and John Canning. "The Acousto-Optic Effect in Microstructured Optical Fibers." In Workshop on Specialty Optical Fibers and their Applications. Washington, D.C.: Optica Publishing Group, 2008. http://dx.doi.org/10.1364/wsof.2008.osd26.
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The acousto-optic effect has been successfully used since the early 80's in the design and construction of a variety of conventional optical fiber devices such as frequency shifters, couplers, filters and modulators. Acoustic waves can be employed to modulate the spectrum and switch the wavelength of conventional fiber Bragg gratings as well as for controlling the Q-switching in distributed fiber lasers. Tunable devices induced by acoustic waves have also been demonstrated in photonic crystal fibers (PCF), whereas a resonance dip corresponding to an excited cladding mode can be tuned over the wavelength. In a similar work, but inducing an acoustic excitation over the longitudinal axis, long period gratings can be created in the transmission band of a solid core PCF. Recently, the availability of Bragg gratings in photonic crystal fibers enables several applications, particularly if their properties can be controlled in order to produce modulation or allow tunability. A way of achieving these effects is through the excitation of acoustic waves in the fibre, which allows a rapid method for shifting or modulating tie Bragg wavelength. In this work the application of acoustic-waves to microstructured fibers is reviewed and recent results on the modulation of fiber Bragg gratings in photonic crystal fibers are presented.
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LANGHORST,, AMY, ELISA HARRISON, ANSHUL SINGHAL, MIHAELA BANU, and ALAN TAUB. "REINFORCEMENT OF NATURAL FIBERS VIA SUPERCRITICAL FLUID INFILTRATION OF NANOPARTICLES." In Proceedings for the American Society for Composites-Thirty Seventh Technical Conference. Destech Publications, Inc., 2022. http://dx.doi.org/10.12783/asc37/36411.
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In recent years, consumer products have been increasingly utilizing sustainable materials to attempt to reduce the product’s carbon footprint. For example, the automotive industry has incorporated a variety of natural fiber polymer composites on vehicles in the last 20 years, including wheat straw in the Ford Flex and flax fibers on the Polestar Precept and the Porsche Cayman GT4 Clubsport. However, natural fibers exhibit lower strength and stiffness in comparison to synthetic reinforcing agents, such as glass fiber. In this work, the authors are developing a technique to improve the mechanical performance of flax fibers for use in structural composites. Supercritical fluids, including supercritical-carbon dioxide (scCO2), have been shown to swell and plasticize amorphous polymers, resulting in increased mass transport and absorption of additives. The weak intercellular region within flax fibers, commonly called the middle lamella, consists mainly of amorphous pectin. In this work, the authors hypothesize that scCO2 could be used to swell amorphous polymers in a fiber’s structure (e.g. pectin) and enable reinforcement with nanoparticles, resulting in fiber performance enhancement. Pectin films were created for proof-of-concept experiments and treated with scCO2 at pressures ranging from 1200-4000psi in the presence of titanium dioxide nanoparticles (TiO2). TiO2 nanoparticles were shown to be able to enter pectin films upon treatment with scCO2 for 24 hours. The same treatment process was used on dew retted, mechanically extracted flax fibers and after treatment for 24 hours, the average tensile strength of the fibers was improved by over 40%. Overall, this method of incorporation of nanoparticles within natural fibers could enable development of low-density, low-carbon footprint polymeric composites for use in structural industrial applications.
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Ramakrishnan, S. "Comparative Study on the Behavior of Fiber Reinforced Concrete." In Sustainable Materials and Smart Practices. Materials Research Forum LLC, 2022. http://dx.doi.org/10.21741/9781644901953-13.
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Abstract. Next to water, concrete is the most consumed material in the world. In the construction industries, concrete is a basic material used for high compressive strength, durable, fire resistant but has low tensile strength. This experimental study aimed to investigation the compressive, tensile and flexural strength of the concrete reinforced with three different fibers. Comparative study has been made between metallic: steel fibers and nonmetallic: glass and carbon fiber reinforced concrete. Fibers were used in concrete with fractions of 0%, 0.5%, 1%, 1.5%, 2% and 2.5% by volume of cement in M20 grade of concrete. In this paper, the behavior of cube, cylinder and prism specimen of fiber reinforced concrete (FRC) were deliberated. Addition of fiber in concrete were increased the basic mechanical properties of concrete increases. The steel fiber reinforced concrete attains higher compressive, flexural and tensile strength than concrete with carbon fiber and glass fiber. Carbon fibered concrete attained higher flexural and tensile strength than glass fibered concrete.
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Banerjee, Hritwick, Nicola Bartolomei, and Fabien Sorin. "Soft Microstructured Optical Fibers via Thermal Drawing." In Specialty Optical Fibers. Washington, D.C.: Optica Publishing Group, 2022. http://dx.doi.org/10.1364/sof.2022.som2h.1.
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The preform-to-fiber thermal drawing of thermoplastic elastomers enables the fabrication of soft multi-material optical fibers with complex architectures. It offers unprecedented opportunities to realize complex soft optical fibers for transmission and sensing.
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Khramov, I., and O. Ryabushkin. "Fiber Laser Power Measurements Using Optical Fibers with Metal Winding." In Specialty Optical Fibers. Washington, D.C.: Optica Publishing Group, 2022. http://dx.doi.org/10.1364/sof.2022.soth3g.3.
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Various optical fibers with copper winding were used for the real-time measuring the fiber lasers output optical power. The mathematical model of the fiber heating allowed determining the induced microbending losses.
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Lyu, Zhouping, and Lyubov V. Amitonova. "Hollow-core fiber imaging." In Specialty Optical Fibers. Washington, D.C.: Optica Publishing Group, 2022. http://dx.doi.org/10.1364/sof.2022.sotu4i.4.
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Multimode fibers serve as high-resolution imaging probes. We show that a hollow-core fiber solves the problems of high background and limited NA. We experimentally demonstrate high-NA raster-scan and compressive imaging through a hollow-core multimode fiber.
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Knight, J. C. "Optics in Microstructured and Photonic Crystal Fibers." In Workshop on Specialty Optical Fibers and their Applications. Washington, D.C.: Optica Publishing Group, 2008. http://dx.doi.org/10.1364/wsof.2008.ps3.
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The development of optical fibers with two-dimensional patterns of air holes running down their length has reinvigorated research in the field of fiber optics. It has greatly–and fundamentally–broadened the range of specialty optical fibers, by demonstrating that optical fibers can be more “special” than previously thought. Fibers with air cores have made it possible to deliver energetic femtosecond-scale optical pulses, transform limited, as solitons, using single-mode fiber. Other fibers with anomalous dispersion at visible wavelengths have spawned a new generation of single-mode optical supercontinuum sources, spanning visible and near-infrared wavelengths and based on compact pump sources. A third example is in the field of fiber lasers, where the use of photonic crystal fiber concepts has led to a new hybrid laser technology, in which the very high numerical aperture available sing air holes have enabled fibers so short they are more naturally held straight than bent. This paper describes some of the basic physics and technology behind these developments, illustrated with some of the impressive demonstrations of the past 18 months.
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Wang, Pu, Zhen Huang, Jing Jiang, and Yongjun Wu. "Performance of Hybrid Fiber Reinforced Concrete with Steel Fibers and Polypropylene Fibers." In International Conference On Civil Engineering And Urban Planning 2012. Reston, VA: American Society of Civil Engineers, 2012. http://dx.doi.org/10.1061/9780784412435.081.
Full textReports on the topic "Fibers"
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Ragalwar, Ketan, William Heard, Brett Williams, Dhanendra Kumar, and Ravi Ranade. On enhancing the mechanical behavior of ultra-high performance concrete through multi-scale fiber reinforcement. Engineer Research and Development Center (U.S.), September 2021. http://dx.doi.org/10.21079/11681/41940.
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Steel fibers are typically used in ultra-high performance concretes (UHPC) to impart flexural ductility and increase fracture toughness. However, the mechanical properties of the steel fibers are underutilized in UHPC, as evidenced by the fact that most of the steel fibers pull out of a UHPC matrix largely undamaged during tensile or flexural tests. This research aims to improve the bond between steel fibers and a UHPC matrix by using steel wool. The underlying mechanism for fiber-matrix bond improvement is the reinforcement of the matrix tunnel, surrounding the steel fibers, by steel wool. Single fiber pullout tests were performed to quantify the effect of steel wool content in UHPC on the fiber-matrix bond. Microscopic observations of pulled-out fibers were used to investigate the fiber-matrix interface. Compared to the control UHPC mixture with no steel wool, significant improvement in the flexural behavior was observed in the UHPC mixtures with steel wool. Thus, the addition of steel wool in steel fiber-reinforced UHPC provides multi-scale reinforcement that leads to significant improvement in fiber-matrix bond and mechanical properties of UHPC.
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Neudecker, Bernd J., Martin H. Benson, and Brian K. Emerson. Power Fibers: Thin-Film Batteries on Fiber Substrates. Fort Belvoir, VA: Defense Technical Information Center, January 2003. http://dx.doi.org/10.21236/ada511230.
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Li, Che-Yu. Strong fibers. Office of Scientific and Technical Information (OSTI), March 1991. http://dx.doi.org/10.2172/5723443.
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Chae, Han Gi. Nanotailored Carbon Fibers. Fort Belvoir, VA: Defense Technical Information Center, June 2009. http://dx.doi.org/10.21236/ada513849.
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Chae, Han Gi. Nanotailored Carbon Fibers. Fort Belvoir, VA: Defense Technical Information Center, April 2012. http://dx.doi.org/10.21236/ada560477.
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Koenig, Jack L., and Shari L. Tidrick. Improved Adhesion Performance of Polyamid Fibers in Fiber-Reinforced Composites. Fort Belvoir, VA: Defense Technical Information Center, May 1989. http://dx.doi.org/10.21236/ada207979.
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Abhiraman, Agaram S. Precursor Structure - Fiber Property Relationships in Polyacrylonitrile- Based Carbon Fibers. Fort Belvoir, VA: Defense Technical Information Center, April 1992. http://dx.doi.org/10.21236/ada249888.
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Granot, David, Scott Holaday, and Randy D. Allen. Enhancing Cotton Fiber Elongation and Cellulose Synthesis by Manipulating Fructokinase Activity. United States Department of Agriculture, 2008. http://dx.doi.org/10.32747/2008.7613878.bard.
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a. Objectives (a) Identification and characterization of the cotton fiber FRKs; (b) Generating transgenic cotton plants overproducing either substrate inhibited tomato FRK or tomato FRK without substrate inhibition; (c) Generating transgenic cotton plants with RNAi suppression of fiber expressed FRKs; (d) Generating Arabidopsis plants that over express FRK1, FRK2, or both genes, as additional means to assess the contribution of FRK to cellulose synthesis and biomass production. b. Background to the topic: Cellulose synthesis and fiber elongation are dependent on sugar metabolism. Previous results suggested that FRKs (fructokinase enzymes that specifically phosphorylate fructose) are major players in sugar metabolism and cellulose synthesis. We therefore hypothesized that increasing fructose phosphorylation may enhance fiber elongation and cellulose synthesis in cotton plants. Accordinlgy, the objectives of this research were: c. Major conclusions and achievements: Two cotton FRKs expressed in fibers, GhFRK2 and GhFRK3, were cloned and characterized. We found that GhFRK2 enzyme is located in the cytosol and GhFRK3 is located within plastids. Both enzymes enable growth on fructose (but not on glucose) of hexose kinase deficient yeast strain, confirming the fructokinase activity of the cloned genes. RNAi constructs with each gene were prepared and sent to the US collaborator to generate cotton plants with RNAi suppression of these genes. To examine the effect of FRKs using Arabidopsis plants we generated transgenic plants expressing either LeFRK1 or LeFRK2 at high level. No visible phenotype has been observed. Yet, plants expressing both genes simultaneously are being created and will be tested. To test our hypothesis that increasing fructose phosphorylation may enhance fiber cellulose synthesis, we generated twenty independent transgenic cotton plant lines overexpressing Lycopersicon (Le) FRK1. Transgene expression was high in leaves and moderate in developing fiber, but enhanced FRK activity in fibers was inconsistent between experiments. Some lines exhibited a 9-11% enhancement of fiber length or strength, but only one line tested had consistent improvement in fiber strength that correlated with elevated FRK activity in the fibers. However, in one experiment, seed cotton mass was improved in all transgenic lines and correlated with enhanced FRK activity in fibers. When greenhouse plants were subjected to severe drought during flowering and boll development, no genotypic differences in fiber quality were noted. Seed cotton mass was improved for two transgenic lines but did not correlate with fiber FRK activity. We conclude that LeFRK1 over-expression in fibers has only a small effect on fiber quality, and any positive effects depend on optimum conditions. The improvement in productivity for greenhouse plants may have been due to better structural development of the water-conducting tissue (xylem) of the stem, since stem diameters were larger for some lines and the activity of FRK in the outer xylem greater than observed for wild-type plants. We are testing this idea and developing other transgenic cotton plants to understand the roles of FRK in fiber and xylem development. We see the potential to develop a cotton plant with improved stem strength and productivity under drought for windy, semi-arid regions where cotton is grown. d. Implications, scientific and agricultural: FRKs are probably bottle neck enzymes for biomass and wood synthesis and their increased expression has the potential to enhance wood and biomass production, not only in cotton plants but also in other feed and energy renewable plants.
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Weiss, Charles, William McGinley, Bradford Songer, Madeline Kuchinski, and Frank Kuchinski. Performance of active porcelain enamel coated fibers for fiber-reinforced concrete : the performance of active porcelain enamel coatings for fiber-reinforced concrete and fiber tests at the University of Louisville. Engineer Research and Development Center (U.S.), May 2021. http://dx.doi.org/10.21079/11681/40683.
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A patented active porcelain enamel coating improves both the bond between the concrete and steel reinforcement as well as its corrosion resistance. A Small Business Innovation Research (SBIR) program to develop a commercial method for production of porcelain-coated fibers was developed in 2015. Market potential of this technology with its steel/concrete bond improvements and corrosion protection suggests that it can compete with other fiber reinforcing systems, with improvements in performance, durability, and cost, especially as compared to smooth fibers incorporated into concrete slabs and beams. Preliminary testing in a Phase 1 SBIR investigation indicated that active ceramic coatings on small diameter wire significantly improved the bond between the wires and the concrete to the point that the wires achieved yield before pullout without affecting the strength of the wire. As part of an SBIR Phase 2 effort, the University of Louisville under contract for Ceramics, Composites and Coatings Inc., proposed an investigation to evaluate active enamel-coated steel fibers in typical concrete applications and in masonry grouts in both tension and compression. Evaluation of the effect of the incorporation of coated fibers into Ultra-High Performance Concrete (UHPC) was examined using flexural and compressive strength testing as well as through nanoindentation.
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Author, Not Given. (Strong fibers): (Progress report). Office of Scientific and Technical Information (OSTI), January 1989. http://dx.doi.org/10.2172/6293863.
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