Academic literature on the topic 'Fiber elongation'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Fiber elongation.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "Fiber elongation"
1
Liu, Guoyuan, Ji Liu, Wenfeng Pei, Xihua Li, Nuohan Wang, Jianjiang Ma, Xinshan Zang, et al. "Analysis of the MIR160 gene family and the role of MIR160a_A05 in regulating fiber length in cotton." Planta 250, no. 6 (October 16, 2019): 2147–58. http://dx.doi.org/10.1007/s00425-019-03271-7.
Full textAbstract:
Abstract Main conclusion The MIR160 family in Gossypium hirsutum and G. barbadense was characterized, and miR160a_A05 was found to increase cotton-fiber length by downregulating its target gene (ARF17) and several GH3 genes. Abstract Cotton fiber is the most important raw material for the textile industry. MicroRNAs are involved in regulating cotton-fiber development, but a role in fiber elongation has not been demonstrated. In this study, miR160a was found to be differentially expressed in elongating fibers between two interspecific (between Gossypium hirsutum and G. barbadense) backcross inbred lines (BILs) with different fiber lengths. The gene MIR160 colocalized with a previously mapped fiber-length quantitative trait locus. Its target gene ARF17 was differentially expressed between the two BILs during fiber elongation, but in the inverse fashion. Bioinformatics was used to analyze the MIR160 family in both G. hirsutum and G. barbadense. Moreover, qRT–PCR analysis identified MIR160a as the functional MIR160 gene encoding the miR160a precursor during fiber elongation. Using virus-induced gene silencing and overexpression, overexpressed MIR160a_A05 resulted in significantly longer fibers compared with wild type, whereas suppression of miR160 resulted in significantly shorter fibers. Expression levels of the target gene auxin-response factor 17 (ARF17) and related genes GH3 in the two BILs and/or the virus-infected plants demonstrated similar changes in response to modulation of miR160a level. Finally, overexpression or suppression of miR160 increased or decreased, respectively, the cellular level of indole-3-acetic acid, which is involved in fiber elongation. These results describe a specific regulatory mechanism for fiber elongation in cotton that can be utilized for future crop improvement.
2
KOUKO, JARMO, TUOMAS TURPEINEN, ARTEM KULACHENKO, ULRICH HIRN, and ELIAS RETULAINEN. "Understanding extensibility of paper: Role of fiber elongation and fiber bonding." March 2020 19, no. 3 (April 1, 2020): 125–35. http://dx.doi.org/10.32964/tj19.3.125.
Full textAbstract:
The tensile tests of individual bleached softwood kraft pulp fibers and sheets, as well as the micro-mechanical simulation of the fiber network, suggest that only a part of the elongation potential of individual fibers is utilized in the elongation of the sheet. The stress-strain curves of two actual individual pulp fibers and one mimicked classic stress-strain behavior of fiber were applied to a micromechanical simulation of random fiber networks. Both the experimental results and the micromechanical simulations indicated that fiber bonding has an important role not only in determining the strength but also the elongation of fiber networks. Additionally, the results indicate that the shape of the stress-strain curve of individual pulp fibers may have a significant influence on the shape of the stress-strain curve of a paper sheet. A large increase in elongation and strength of paper can be reached only by strength-ening fiber-fiber bonding, as demonstrated by the experimental handsheets containing starch and cellulose microfi-brils and by the micromechanical simulations. The key conclusion related to this investigation was that simulated uniform inter-fiber bond strength does not influence the shape of the stress-strain curve of the fiber network until the bonds fail, whereas the number of bonds has an influence on the activation of the fiber network and on the shape of the whole stress-strain curve.
3
Yang, Qing Bin, and Yu Kun Dou. "The Strength and Elongation of PLA Fiber Yarn." Advanced Materials Research 460 (February 2012): 271–74. http://dx.doi.org/10.4028/www.scientific.net/amr.460.271.
Full textAbstract:
The PLA fiber is one of the green fibers. It is blended with Tencel fibers. The strength of the PLA fiber/Tencel blended yarn is tested. The relationship between the strength and the twist factor and the blended ratio is analyzed. The optimum blended ratio and the critical twist factor of the blended yarn is determined.
4
Amanuel, Lami. "Palm leaf sheath fiber extraction and surface modification." Journal of Engineered Fibers and Fabrics 15 (January 2020): 155892502095072. http://dx.doi.org/10.1177/1558925020950724.
Full textAbstract:
The influence of softening on tensile strength, elongation at break, moisture regain and microscopic morphology of Palm Sheath fiber extracted by chemical degumming using 80% sodium hydroxide; bleached by hydrogen peroxide and softened by silicone emulsion softener was studied. The softened and unsoftened fibers were characterized for their longitudinal view, tensile strength and elongation at break of single fiber by scanning electron microscope (SEM). The single fiber tensile strength and elongation at break were 19.6% and 10.22% respectively. The calculated value of moisture regain and moisture content of the softened fibers was 12.65% and 11.23% respectively. The tensile strength, elongation at break, moisture management of the softened palm sheath fiber was significantly higher. As a result of surface modification microscopic morphology, the treated fiber was also found different. The study result had drawn the significant influence of the surface modification on the forth mentioned properties of the extracted palm leaf sheath fiber.
5
Gorshkov, Oleg, Tatyana Chernova, Natalia Mokshina, Natalia Gogoleva, Dmitry Suslov, Alexander Tkachenko, and Tatyana Gorshkova. "Intrusive Growth of Phloem Fibers in Flax Stem: Integrated Analysis of miRNA and mRNA Expression Profiles." Plants 8, no. 2 (February 19, 2019): 47. http://dx.doi.org/10.3390/plants8020047.
Full textAbstract:
Phloem fibers are important elements of plant architecture and the target product of many fiber crops. A key stage in fiber development is intrusive elongation, the mechanisms of which are largely unknown. Integrated analysis of miRNA and mRNA expression profiles in intrusivelygrowing fibers obtained by laser microdissection from flax (Linum usitatissimum L.) stem revealed all 124 known flax miRNA from 23 gene families and the potential targets of differentially expressed miRNAs. A comparison of the expression between phloem fibers at different developmental stages, and parenchyma and xylem tissues demonstrated that members of miR159, miR166, miR167, miR319, miR396 families were down-regulated in intrusively growing fibers. Some putative target genes of these miRNA families, such as those putatively encoding growth-regulating factors, an argonaute family protein, and a homeobox-leucine zipper family protein were up-regulated in elongating fibers. miR160, miR169, miR390, and miR394 showed increased expression. Changes in the expression levels of miRNAs and their target genes did not match expectations for the majority of predicted target genes. Taken together, poorly understood intrusive fiber elongation, the key process of phloem fiber development, was characterized from a miRNA-target point of view, giving new insights into its regulation.
6
STERNER, MARION, and MIKAEL MAGNUSSON. "Innovative technology for making improved paper from the poorest fibers." November 2017 16, no. 11 (2017): 633–37. http://dx.doi.org/10.32964/tj16.11.633.
Full textAbstract:
The trademarked Papermorphosis technology, consisting of two novel units for separately increasing cross direction (CD) and machine direction (MD) elongation over purely mechanical processes, has been successfully tested on recycling fiber, reaching high elongation values in each direction of over 15% in CD or 20% in MD. Increase of elongation has also had a positive influence on the relative tensile energy absorption (TEA) values in CD and MD. It is well known that mechanical properties in paper basically depend on fiber choice, headbox properties, and refining. With the novel system, elongations in cross direction (CD) and machine direction (MD) can be individually customized, even in paper grades with lower strength deriving from recycled fiber. Customizing elongations also has the effect of improving or better balancing TEA values in both directions. The aim is to improve existing recycling papers and to broaden the use of recycling fiber with respect to the past.
7
Zieliński, Tomasz, and Łukasz Zychowicz. "ANALISYS OF THE INFLUENCE OF GLUE JOINTS ON THE MEASUREMENT OF PHYSICAL PROPERTIES OF STRUCTURAL ELEMENTS USING FIBER BRAGG GRATING." Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska 10, no. 3 (September 30, 2020): 99–102. http://dx.doi.org/10.35784/iapgos.2353.
Full textAbstract:
The research presents the analysis of the influence of the glue connection on the measurement of elongation of stainless steel and aluminum samples by means of fiber Bragg grating (FBG) with uniform fibers used as a measuring transducer. Research indicates two possible factors affecting the deformation of the transmission spectrum obtained during elongation measurement. One of them is the type of adhesive that is used to make the connection between the fiber Bragg grating and the tested sample. The second possible factor is method of connection's execution. The need for research on glue connection resulted from the formation of defects mainly in the form of numerous side bands visible in the transmission spectrum during the measurement of elongations. The test results were presented in the form of graphs obtained on the basis of transmission characteristic.
8
McCormick, Kolby M., João Paulo Saraiva Morais, Eric Hequet, and Brendan Kelly. "Development of the correction procedure for High Volume Instrument elongation measurement." Textile Research Journal 89, no. 19-20 (February 11, 2019): 4095–103. http://dx.doi.org/10.1177/0040517519829002.
Full textAbstract:
Cotton spinning mills need high-quality fibers to maintain their manufacturing efficiency. Machinery throughput is increasing and it could translate into more processes with higher breaking stress. Consequently, more fibers are susceptible to breaking or damage. To face this problem, breeders must develop new varieties whose fibers can better withstand this mechanical stress. The main tool utilized in cotton breeding programs is the High Volume Instrument (HVI), which reports in a short time measurements such as micronaire, length, color, and strength. This instrument can also determine fiber elongation, but there is no current correction method for it. Both elongation and strength factor into the work-to-break of fibers, which plays a direct role in fiber breakage and spinning performance. The objective of this work was to develop cotton elongation standards, devise a correction procedure for HVI lines, evaluate measurement stability, and validate these results with a set of independent samples. Two commercial bales, one with low and one with high HVI elongation, were identified as potential elongation standards. The potential standards were produced and evaluated. After validation, they were used to correct HVI lines against Stelometer (STrength-ELOngation-METER) measurements. An independent set of samples was tested on corrected HVIs to confirm the effectiveness of the elongation corrected measurements. The HVI data were at least as good as the Stelometer data, with increased data acquisition speed and precision. This research can help cotton breeders to improve fiber elongation and strength at the same time, resulting in better fibers for yarn spinning.
9
Szustakowski, M., N. Palka, and W. Ciurapinski. "Contrastometric fiber optic elongation sensor." Journal de Physique IV (Proceedings) 129 (October 2005): 165–67. http://dx.doi.org/10.1051/jp4:2005129035.
Full text
10
Mathangadeera, Ruvini W., Eric F. Hequet, Brendan Kelly, Jane K. Dever, and Carol M. Kelly. "Importance of cotton fiber elongation in fiber processing." Industrial Crops and Products 147 (May 2020): 112217. http://dx.doi.org/10.1016/j.indcrop.2020.112217.
Full textDissertations / Theses on the topic "Fiber elongation"
1
Mujahid, Hana, Ken Pendarvis, Joseph Reddy, Babi Nallamilli, K. Reddy, Bindu Nanduri, and Zhaohua Peng. "Comparative Proteomic Analysis of Cotton Fiber Development and Protein Extraction Method Comparison in Late Stage Fibers." MDPI AG, 2016. http://hdl.handle.net/10150/618719.
Full textAbstract:
The distinct stages of cotton fiber development and maturation serve as a single-celled model for studying the molecular mechanisms of plant cell elongation, cell wall development and cellulose biosynthesis. However, this model system of plant cell development is compromised for proteomic studies due to a lack of an efficient protein extraction method during the later stages of fiber development, because of a recalcitrant cell wall and the presence of abundant phenolic compounds. Here, we compared the quality and quantities of proteins extracted from 25 dpa (days post anthesis) fiber with multiple protein extraction methods and present a comprehensive quantitative proteomic study of fiber development from 10 dpa to 25 dpa. Comparative analysis using a label-free quantification method revealed 287 differentially-expressed proteins in the 10 dpa to 25 dpa fiber developmental period. Proteins involved in cell wall metabolism and regulation, cytoskeleton development and carbohydrate metabolism among other functional categories in four fiber developmental stages were identified. Our studies provide protocols for protein extraction from maturing fiber tissues for mass spectrometry analysis and expand knowledge of the proteomic profile of cotton fiber development.
2
Oh, Kyung Hee. "Effect of shear, elongation and phase separation in hollow fiber membrane spinning." Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/53992.
Full textAbstract:
The spinning process of hollow fiber membranes was investigated with regards to two fundamental phenomena: flow (shear and elongation) and phase separation. Quantitative analysis of phase separation kinetics of binary (polymer/solvent) and ternary (polymer/solvent/volatile co-solvent) polymer solution was carried out with a newly developed microfluidic device. The device enables visualization of in situ phase separation and structure formation in controlled vapor and liquid environments. Results from these studies indicated that there was a weak correlation between phase separation kinetics and macroscopic defect (macrovoid) formation. In addition, the effect of shear and elongation on membrane morphology was tested by performing fiber extrusion through microfluidic channels. It was found that the membrane morphology is dominated by different factors depending on the rate of deformation. At high shear rates typical of spinning processes, shear was found to induce macrovoid formation through normal stresses, while elongation suppressed macroscopic defect formation. Furthermore, draw resonance, one of the key instabilities that can occur during fiber spinning, was investigated. It was found that draw resonance occurs at aggressive elongation condition, and could be suppressed by enhanced phase separation kinetics. These results can be used as guidelines for predicting hollow fiber membrane spinnability.
3
Gagov, Atanas. "INSTABILITIES IN ELONGATION FLOWS OF POLYMERS AT HIGH DEBORAH NUMBERS." University of Akron / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=akron1191895515.
Full text
4
Asprodites, Nicole. "The Cloning and Characterization of Two ROP/RAC G-Proteins from Gossypium Hirsutum." ScholarWorks@UNO, 2005. http://scholarworks.uno.edu/td/233.
Full textAbstract:
Rop/Rac proteins are plant-specific monomeric guanosine triphosphate-binding proteins (G-proteins) with important functions in plant development. Until recently, only three cotton (Gossypium hirsutum) Rop/Rac G-protein genes were sequenced, representing subfamilies III and IV of the plant monomeric Gprotein family. In this project, members of subfamilies II and I were cloned, sequenced, and named GhRac2 and GhRac3, respectively. Using real-time reverse transcription PCR, expression of GhRac2 was highest during fiber elongation, decreasing significantly when cellulose biosynthesis began. Transcript abundance of GhRac3 doubled between fiber elongation and secondary wall synthesis, remaining constant until 20 days post-anthesis. Expression of GhRac2 and GhRac3 was compared between the unfertilized ovules of Gossypium hirsutum, Texas Marker 1 and two near-isogenic fiber-impaired mutants. Expression of GhRac2 and GhRac3 was significantly higher in wild type ovules than in Ligon lintless, a mutant impaired in fiber elongation, but was not different in Naked Seed, a mutant impaired in fiber initiation.
5
Wolfinger, Tobias. "Dreidimensionale Strukturanalyse und Modellierung des Kraft-Dehnungsverhaltens von Fasergefügen." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-220634.
Full textAbstract:
Der Einsatz von Fasergefügen und insbesondere von Papier geht heute über dessen ursprüngliches Anwendungsgebiet als Informationsträger weit hinaus. Mit alternativen und neuen Aufgabenfeldern des Papiers kommen auch weitere, qualitative Anforderungen hinzu, welche es während der Herstellung, Weiterverarbeitung und Nutzung erfüllen muss. In der Vergangenheit stand verstärkt z.B. die Verbesserung der statischen und dynamischen Festigkeitseigenschaften im Vordergrund. Für viele Anwendungsfälle spielt jedoch auch die Dehnung eine entscheidende Rolle. Beispiele sind Sackpapier oder Elektroisolationspapier.
Darum verfolgt diese Arbeit das Ziel, systematisch und anhand eines neuen Dehnungsmodells, qualitativ und quantitativ die Einflüsse der Faser- und Gefügeeigenschaften anhand ausgewählter Prozessbedingungen auf das Kraft-Dehnungsverhalten, aber insbesondere auf dessen Dehnung zu untersuchen. Des Weiteren wurde eine Methode entwickelt, mit der es unter Nutzung eines Röntgen-Computertomographen möglich ist, weitere Gefügeparameter, auch während einer semi-dynamischen Zugprüfung in-situ zu ermitteln. Für die Bewertung der Fasereigenschaften wurden vier Faserstoffe ausgewählt. Zum Einsatz kam ein ungebleichter Nadelholzsulfatzellstoff (UKP), ein gebleichter Eukalyptuszellstoff, Baumwolllinters und Tencel, eine synthetische Cellulosefaser. Diese Faserstoffe sind chemisch und morphologisch analysiert worden, bevor sie sowohl überwiegend fibrillierend als auch überwiegend kürzend in einem Refiner gemahlen wurden. Nach unterschiedlich hohem Eintrag an massenspezifischer Mahlarbeit in den Faserstoff wurden aus der Suspension Papiermuster gebildet, schrumpfungsbehindert getrocknet und charakterisiert. Durch die Mahlung der Faserstoffe erfolgte eine Reduktion deren mittlerer längengewichteter Faserkonturlänge, der Feinstoffanteil konnte gesteigert werden und das Wasserrückhaltevermögen nahm zu. Es konnte ein unterschiedliches Verhalten der Entwicklung des Wasserrückhaltevermögens zwischen dem ungebleichten Nadelholzsulfatzellstoff und dem gebleichten Eukalyptus gegenüber den Baumwolllinters und den Tencelfasern gefunden werden. Das Wasserrückhaltevermögen von Baumwolllinters und den Tencelfasern blieb, unabhängig von der Mahlstrategie, fast bis zum maximalen Eintrag an massenspezifischer Mahlarbeit von ca. 770 kWh/t unbeeinflusst. Mit den erhaltenen Kraft-Dehnungsdiagrammen der Papiermuster, welche durch eine uniaxiale Zugprüfung mit konstanter Dehnungsgeschwindigkeit messtechnisch erfasst wurden, konnte durch eine Kurveneinpassung mit dem entwickelten Dehnungsmodell das jeweilige Kraft-Dehnungsverhalten mathematisch nachgebildet werden. Dieser neue Modellansatz wurde gewählt, nachdem die Auswertung des Ansatzes von Paetow [77;78;79;90] zu große Abweichungen bei bestimmten Papiermustern aufzeigte. Dies ermöglichte die quantitative Auswertung relevanter Parameter der Kraft-Dehnungskurven. Dabei wurden der Elastizitätsmodul, die Reißlänge und die Dehnung bei maximaler Reißlänge bewertet. Eine sehr hohe Reißlänge konnte mit einem fibrillierend gemahlenem, ungebleichtem Nadelholzsulfatzellstoff und eine hohe Dehnung mit einem, ebenfalls fibrillierend gemahlenem Eukalyptuszellstoff erreicht werden. Des Weiteren sind die Reißlänge am Übergang von einem initial linearen in den nicht-linearen Kurventeil, ein Abknickfaktor sowie der weitere Kurvenverlauf nach dem nicht-linearen Bereich, bis zur maximalen Reißlänge des Gefüges bewertet worden. Der letzte Kurvenbereich wurde entweder durch den weiteren, nicht-linearen Verlauf oder durch einen sekundären Linearbereich charakterisiert. Der von Seth und Page [22] dargestellte Einfluss der Faserstoffmahlung auf den Verlauf der Kraft-Dehnungskurve von Papier konnte nicht nachgebildet werden. Dies zeigte auch, dass die in dieser Arbeit gewonnenen Erkenntnisse durch eine Korrektur des Elastizitätsmoduls mit den Kraft-Dehnungskurven nicht mit den Ergebnissen aus [22] übereinstimmen. Die Faserstoffmahlung hat demnach nicht nur einen Einfluss auf die maximal erreichbare Reißlänge und Dehnung, sondern beeinflusst auch den qualitativen Verlauf der Kraft-Dehnungskurve von Papier. Es konnten keine individuellen Einflussgröße der Fasermorphologie und der Prozessparameter auf die Dehnung oder das Kraft-Dehnungsverhalten festgestellt werden, da sich die meisten dieser Eigenschaften direkt mit der eingebrachten, massenspezifischen Mahlarbeit verändern, die Papierdehnung jedoch schon nach Erreichen einer moderaten massenspezifischen Mahlarbeit von ca. 100 – 200 kWh/t nicht weiter steigern ließ. Für eine weitere Bewertung der Einflüsse auf das Kraft-Dehnungsverhalten von Papier wurden Messwerte aus [143] analysiert. Dabei zeigte sich, dass ein Anstieg an Fasern mit einer hohen Faserkräuselung die Reißlänge des Papiers sowie den Elastizitätsmodul signifikant reduziert. Die Reißlänge am Kurvenübergang vom initial linearen in den nicht-linearen Teil bleibt dabei jedoch konstant. Ein anderes Verhalten, welches mit den Ergebnissen von Seth und Page [22] sowie Lowe [12] übereinstimmt, ist die Auswirkung eines kationischen Additivs wie z.B. Stärke auf die Entwicklung des Kraft-Dehnungsverhaltens.
Es konnte nachgewiesen werden, dass das Additiv keinerlei Einfluss auf den initial linearen sowie den nicht-linearen Teil der Kraft-Dehnungskurve hat, sondern nur den sekundären, linearen Kurvenbereich in Abhängigkeit der Dosiermenge beeinflusst. Dabei wurde die Steigung im sekundären Linearbereich bestimmt. Dieses Verhalten führte zu einer Erweiterung der Theorie von Kallmes [82], welcher nach einem Anstieg der Festigkeit und der Dehnung, ab einer kritischen, relativen Bindungsfläche nur noch einen Anstieg der Festigkeit vorhersagte, jedoch nicht mehr der Dehnung. Auf Grund der in dieser Arbeit gewonnenen Erkenntnisse müssen drei Fälle der Entwicklung des Kraft-Dehnungsverhaltens von Fasergefügen unterschieden werden, welche primär von der Homogenität der Spannungsverteilung im Fasergefüge abhängig sind und z.B. durch die Faserkräuselung oder Blattformation beeinflusst werden kann. Diese neue Ansicht basiert auf dem Verhältnis zwischen der Bindungsenergie der Faser-Faserbindung und dem formbasierten sowie dem längenbasierten Arbeitsaufnahmevermögen der Fasern. Der erste Fall der Gefügedehnung beschreibt das Verhalten, wenn die Bindungsenergie geringer ist als das formbasierte Arbeitsaufnahmevermögen. Dies führt zu einem Auseinandergleiten des Fasergefüges. Dieses Verhalten konnte mit der Analyse von Papierproben aus Linters im Röntgen-Computertomograph qualitativ nachgewiesen werden. Steigt die Bindungsenergie an, wie es der zweite Fall voraussetzt, kann das formbasierte Arbeitsvermögen der Fasern überwunden werden und steht als Dehnvermögen zur Verfügung. Um auch, wie es der dritte Fall beschreibt, das längenbasierte Dehnvermögen der Fasern nutzen zu können, muss die Bindungsenergie zusätzlich durch z.B. ein Additiv oder hohe Drücke in einer Nasspresse weiter steigen.
Die erweiterte Theorie bildet nun das gesamte Kraft-Dehnungsverhalten von Fasergefügen ab und muss in weiteren Arbeiten zur Papieranalyse verifiziert werden. Eine wertvolle Ergänzung der zu ermittelnden Gefügeparameter kann durch die entwickelte Methode mit der Röntgen-Computertomographie geleistet werden.
6
Hagen, Thomas Ch. "Elongational Flows in Polymer Processing." Diss., Virginia Tech, 1998. http://hdl.handle.net/10919/29437.
Full textAbstract:
The production of long, thin polymeric fibers is a main objective of the textile industry. Melt-spinning is a particularly simple and effective technique. In this work, we shall discuss the equations of melt-spinning in viscous and viscoelastic flow. These quasilinear hyperbolic equations model the uniaxial extension of a fluid thread before its solidification.
We will address the following topics: first we shall prove existence, uniqueness, and regularity of solutions. Our solution strategy will be developed in detail for the viscous case. For non-Newtonian and isothermal flows, we shall outline the general ideas. Our solution technique consists of energy estimates and fixed-point arguments in appropriate Banach spaces. The existence result for a simple transport equation is the key to understanding the quasilinear case. The second issue of this exposition will be the stability of the unforced frost line formation. We will give a rigorous justification that, in the viscous regime, the linearized equations obey the ``Principle of Linear Stability''. As a consequence, we are allowed to relate the stability of the associated strongly continuous semigroup to the numerical resolution of the spectrum of its generator. By using a spectral collocation method, we shall derive numerical results on the eigenvalue distribution, thereby confirming prior results on the stability of the steady-state solution.Ph. D.
7
Ng, Eng Hwa. "Genetics of Cotton Fiber Elongation." Thesis, 2013. http://hdl.handle.net/1969.1/151034.
Full textAbstract:
Fiber elongation (ability to stretch before breaking) is one of the key components in determining overall yarn quality. Elongation in U.S. upland cotton (G. hirsutum L.) has remained largely neglected due to: absence of monetary incentives for growers to produce high elongation cotton; lack of research interests among breeders; and absence of a reliable fiber testing system for elongation. This study was conducted to determine the genetics of cotton fiber elongation via a diallel and generation means analysis (GMA). Findings from this study should lay the foundation for future breeding work in cotton fiber elongation.
Of the seven distinctive upland parents used for the diallel study, general combining ability was far more prominent than specific combing ability for fiber elongation. Cultivar PSC 355 and Dever experimental line were the two parents identified as good combiners for fiber elongation in this study. The slight negative correlation between fiber elongation and strength remained true. Highly significant negative correlation was observed between fiber upper half mean length and elongation. Both Stelometer and HVI elongation measurements correlated well with values of 0.85 and 0.82 in 2010 and 2011, respectively. For the six families used in the GMA analysis, additive genetic control was prevalent over dominance effect. Based on the scaling test, no significant epistatic interaction was detected for fiber elongation. As expected, additive variance constituted a much larger portion of total genetic variation in fiber elongation than the dominance variance. On average, larger numbers of effective factor were identified in fiber elongation than all other fiber traits tested, suggesting that parents used in the GMA study are carrying different genetic materials/ loci for fiber elongation. Considerable gains in fiber elongation may be achieved by selectively crossing these materials in a pure-line breeding scheme while holding other important fiber traits constant.
8
Osorio, Marin Juliana 1982. "Improvement of Work-to-Break Characteristics of Cotton (Gossypium hirsutum L.) Fibers and Yarn through Breeding and Selection for Improved Fiber Elongation." Thesis, 2012. http://hdl.handle.net/1969.1/148196.
Full textAbstract:
The development of cottons with improved fiber quality has been a major objective in breeding programs around the world. Breeders have focused their attention on improving fiber strength and length, and have generally not used fiber elongation in the selection process. Although literature has reported a negative correlation between fiber elongation and tenacity, this correlation is weak and should not prevent breeders from simultaneously improving fiber tenacity and fiber elongation. Furthermore, the work of rupture property, important in the spinning process, could be best enhanced by improving both fiber tenacity and fiber elongation.
Fifteen populations were developed in 2007 by crossing good quality breeding lines with high elongation measurements to ‘FM 958’; a High Plains standard cultivar with good fiber quality but reduced elongation. Samples in every generation were ginned on a laboratory saw gin, and the lint was tested on HVI (High Volume Instrument). The F2 and F3 generations showed a wide range of variation for elongation (6.9% - 12.8% for the F2 and 4% - 9.20% for the F3) allowing divergent selection for low and high fiber elongation. A correlation (r) of -0.32 between strength and elongation was observed in the F2 individual plant selections. In the F3, the correlation (r) between strength and elongation was -0.36, and in the F4 the correlation (r) was -0.08. Nine lines were selected from the original 15 populations for spinning tests. The correlation between fiber elongation and strength for these lines was positive (r=0.424), indicating that with targeted selection, fiber elongation and strength can be simultaneously improved.
Fiber elongation was positively correlated with yarn tensile properties tenacity (r=0.11), work-to-break (r=0.68) and breaking elongation (r=0.87); and was negatively correlated with yarn evenness properties, number of thin places (r=-0.16), number of thick places (r=-0.9), nep count (r=-0.24), hairiness (r=-0.38) and total number of imperfections (r=-0.38). All selections for high elongation were superior for all tensile properties compared to the low selections and the check in the analysis over locations and in each location. Furthermore, selections for high elongation were significantly different from the selections for low elongation and the check.
In addition to developing lines for fiber spinning tests with improved, or differentiated, fiber elongation, this project was amended to evaluate and determine the heritability of fiber elongation. Three different methodologies were used to obtain estimates of heritability; variance components, parent off-spring regression, and realized heritability using F3, F4, and F5 generation. No inbreeding was assumed because there was no family structure in the generations within this study. Estimates of heritability by the variance component methods in the F3, F4 and F5 were 69.5%, 56.75% and 47.9% respectively; indicating that 40-50% of the variation was due to non-genetic effects. Parent off-spring regression estimates of heritability were 66.1% for the F3-4 and 62.8% for the F4-5; indicating a high resemblance from parents to off-spring. Estimates of realized heritability were obtained to determine the progress realized from selection for the low and high selection for fiber elongation. Estimates were intermediate (0.44–0.55), indicating moderately good progress from selection.
The results from this project demonstrate that it is possible to improve fiber elongation and to break the negative correlation between elongation and strength. Furthermore, it has been demonstrated that improving fiber elongation results in the increase of length uniformity index and decreased short fiber content. Additionally, directed divergent selection was a successful methodology for the improvement of fiber elongation, and was useful to demonstrate that higher fiber elongation has a positive effect on yarn tensile properties, yarn evenness and processing. The development of new cultivars with improved fiber elongation will improve the quality and reputation of U. S.-grown cotton. The ultimate result will be better yarn quality and improved weaving efficiency, and particularly address current weaknesses in U. S. –grown cotton cultivars, especially from the High Plains of Texas, of more short fiber content, lower uniformity ratios, and weaker yarn strength.
9
Wolfinger, Tobias. "Dreidimensionale Strukturanalyse und Modellierung des Kraft-Dehnungsverhaltens von Fasergefügen." Doctoral thesis, 2016. https://tud.qucosa.de/id/qucosa%3A30208.
Full textAbstract:
Der Einsatz von Fasergefügen und insbesondere von Papier geht heute über dessen ursprüngliches Anwendungsgebiet als Informationsträger weit hinaus. Mit alternativen und neuen Aufgabenfeldern des Papiers kommen auch weitere, qualitative Anforderungen hinzu, welche es während der Herstellung, Weiterverarbeitung und Nutzung erfüllen muss. In der Vergangenheit stand verstärkt z.B. die Verbesserung der statischen und dynamischen Festigkeitseigenschaften im Vordergrund. Für viele Anwendungsfälle spielt jedoch auch die Dehnung eine entscheidende Rolle. Beispiele sind Sackpapier oder Elektroisolationspapier.
Darum verfolgt diese Arbeit das Ziel, systematisch und anhand eines neuen Dehnungsmodells, qualitativ und quantitativ die Einflüsse der Faser- und Gefügeeigenschaften anhand ausgewählter Prozessbedingungen auf das Kraft-Dehnungsverhalten, aber insbesondere auf dessen Dehnung zu untersuchen. Des Weiteren wurde eine Methode entwickelt, mit der es unter Nutzung eines Röntgen-Computertomographen möglich ist, weitere Gefügeparameter, auch während einer semi-dynamischen Zugprüfung in-situ zu ermitteln. Für die Bewertung der Fasereigenschaften wurden vier Faserstoffe ausgewählt. Zum Einsatz kam ein ungebleichter Nadelholzsulfatzellstoff (UKP), ein gebleichter Eukalyptuszellstoff, Baumwolllinters und Tencel, eine synthetische Cellulosefaser. Diese Faserstoffe sind chemisch und morphologisch analysiert worden, bevor sie sowohl überwiegend fibrillierend als auch überwiegend kürzend in einem Refiner gemahlen wurden. Nach unterschiedlich hohem Eintrag an massenspezifischer Mahlarbeit in den Faserstoff wurden aus der Suspension Papiermuster gebildet, schrumpfungsbehindert getrocknet und charakterisiert. Durch die Mahlung der Faserstoffe erfolgte eine Reduktion deren mittlerer längengewichteter Faserkonturlänge, der Feinstoffanteil konnte gesteigert werden und das Wasserrückhaltevermögen nahm zu. Es konnte ein unterschiedliches Verhalten der Entwicklung des Wasserrückhaltevermögens zwischen dem ungebleichten Nadelholzsulfatzellstoff und dem gebleichten Eukalyptus gegenüber den Baumwolllinters und den Tencelfasern gefunden werden. Das Wasserrückhaltevermögen von Baumwolllinters und den Tencelfasern blieb, unabhängig von der Mahlstrategie, fast bis zum maximalen Eintrag an massenspezifischer Mahlarbeit von ca. 770 kWh/t unbeeinflusst. Mit den erhaltenen Kraft-Dehnungsdiagrammen der Papiermuster, welche durch eine uniaxiale Zugprüfung mit konstanter Dehnungsgeschwindigkeit messtechnisch erfasst wurden, konnte durch eine Kurveneinpassung mit dem entwickelten Dehnungsmodell das jeweilige Kraft-Dehnungsverhalten mathematisch nachgebildet werden. Dieser neue Modellansatz wurde gewählt, nachdem die Auswertung des Ansatzes von Paetow [77;78;79;90] zu große Abweichungen bei bestimmten Papiermustern aufzeigte. Dies ermöglichte die quantitative Auswertung relevanter Parameter der Kraft-Dehnungskurven. Dabei wurden der Elastizitätsmodul, die Reißlänge und die Dehnung bei maximaler Reißlänge bewertet. Eine sehr hohe Reißlänge konnte mit einem fibrillierend gemahlenem, ungebleichtem Nadelholzsulfatzellstoff und eine hohe Dehnung mit einem, ebenfalls fibrillierend gemahlenem Eukalyptuszellstoff erreicht werden. Des Weiteren sind die Reißlänge am Übergang von einem initial linearen in den nicht-linearen Kurventeil, ein Abknickfaktor sowie der weitere Kurvenverlauf nach dem nicht-linearen Bereich, bis zur maximalen Reißlänge des Gefüges bewertet worden. Der letzte Kurvenbereich wurde entweder durch den weiteren, nicht-linearen Verlauf oder durch einen sekundären Linearbereich charakterisiert. Der von Seth und Page [22] dargestellte Einfluss der Faserstoffmahlung auf den Verlauf der Kraft-Dehnungskurve von Papier konnte nicht nachgebildet werden. Dies zeigte auch, dass die in dieser Arbeit gewonnenen Erkenntnisse durch eine Korrektur des Elastizitätsmoduls mit den Kraft-Dehnungskurven nicht mit den Ergebnissen aus [22] übereinstimmen. Die Faserstoffmahlung hat demnach nicht nur einen Einfluss auf die maximal erreichbare Reißlänge und Dehnung, sondern beeinflusst auch den qualitativen Verlauf der Kraft-Dehnungskurve von Papier. Es konnten keine individuellen Einflussgröße der Fasermorphologie und der Prozessparameter auf die Dehnung oder das Kraft-Dehnungsverhalten festgestellt werden, da sich die meisten dieser Eigenschaften direkt mit der eingebrachten, massenspezifischen Mahlarbeit verändern, die Papierdehnung jedoch schon nach Erreichen einer moderaten massenspezifischen Mahlarbeit von ca. 100 – 200 kWh/t nicht weiter steigern ließ. Für eine weitere Bewertung der Einflüsse auf das Kraft-Dehnungsverhalten von Papier wurden Messwerte aus [143] analysiert. Dabei zeigte sich, dass ein Anstieg an Fasern mit einer hohen Faserkräuselung die Reißlänge des Papiers sowie den Elastizitätsmodul signifikant reduziert. Die Reißlänge am Kurvenübergang vom initial linearen in den nicht-linearen Teil bleibt dabei jedoch konstant. Ein anderes Verhalten, welches mit den Ergebnissen von Seth und Page [22] sowie Lowe [12] übereinstimmt, ist die Auswirkung eines kationischen Additivs wie z.B. Stärke auf die Entwicklung des Kraft-Dehnungsverhaltens.
Es konnte nachgewiesen werden, dass das Additiv keinerlei Einfluss auf den initial linearen sowie den nicht-linearen Teil der Kraft-Dehnungskurve hat, sondern nur den sekundären, linearen Kurvenbereich in Abhängigkeit der Dosiermenge beeinflusst. Dabei wurde die Steigung im sekundären Linearbereich bestimmt. Dieses Verhalten führte zu einer Erweiterung der Theorie von Kallmes [82], welcher nach einem Anstieg der Festigkeit und der Dehnung, ab einer kritischen, relativen Bindungsfläche nur noch einen Anstieg der Festigkeit vorhersagte, jedoch nicht mehr der Dehnung. Auf Grund der in dieser Arbeit gewonnenen Erkenntnisse müssen drei Fälle der Entwicklung des Kraft-Dehnungsverhaltens von Fasergefügen unterschieden werden, welche primär von der Homogenität der Spannungsverteilung im Fasergefüge abhängig sind und z.B. durch die Faserkräuselung oder Blattformation beeinflusst werden kann. Diese neue Ansicht basiert auf dem Verhältnis zwischen der Bindungsenergie der Faser-Faserbindung und dem formbasierten sowie dem längenbasierten Arbeitsaufnahmevermögen der Fasern. Der erste Fall der Gefügedehnung beschreibt das Verhalten, wenn die Bindungsenergie geringer ist als das formbasierte Arbeitsaufnahmevermögen. Dies führt zu einem Auseinandergleiten des Fasergefüges. Dieses Verhalten konnte mit der Analyse von Papierproben aus Linters im Röntgen-Computertomograph qualitativ nachgewiesen werden. Steigt die Bindungsenergie an, wie es der zweite Fall voraussetzt, kann das formbasierte Arbeitsvermögen der Fasern überwunden werden und steht als Dehnvermögen zur Verfügung. Um auch, wie es der dritte Fall beschreibt, das längenbasierte Dehnvermögen der Fasern nutzen zu können, muss die Bindungsenergie zusätzlich durch z.B. ein Additiv oder hohe Drücke in einer Nasspresse weiter steigen.
Die erweiterte Theorie bildet nun das gesamte Kraft-Dehnungsverhalten von Fasergefügen ab und muss in weiteren Arbeiten zur Papieranalyse verifiziert werden. Eine wertvolle Ergänzung der zu ermittelnden Gefügeparameter kann durch die entwickelte Methode mit der Röntgen-Computertomographie geleistet werden.
10
Chiu, Chih-Wei, and 邱智瑋. "Spinning and Elongational Flow Behaviorof Nanoscale TiO2/PP Fibers." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/38752224919974318854.
Full textAbstract:
碩士逢甲大學
紡織工程所
92
Nano-scale TiO2/Polypropylene fibers are prepared by melt blending with melt spinning process in this study. The elongational viscosity characteristic of polymer effects by the condition of manufacture, it can be measured in spinning process. The particle size, additive amounts of the nano-scale TiO2 particles are varied, and the temperature, volume flow rate and extracted speed tension are the parameters of this experiment. It is directly measured the diameter, tension, and flow rate of fibers, and calculate apparent elongational viscosity and apparent elongational strain rate by Cogswell’s theory. By the way to obtain the effects while manufacture it. The thermal property are measured by DSC and TGA, and obtained the surface property by AFM. According the relationship of diameter and distance from die are affected by different processes, the diameter of Polypropylene and distance from die of Polypropylene melts will increase with the smaller particles of TiO2, and the diameter and distance from die of Polypropylene melts will increase with additive amounts of the nano-scale TiO2 and volume flow rate increase. The diameter of Polypropylene and distance from die of Polypropylene melts decrease with the increased temperature and extracted speed tension. The elongational viscosity of Polypropylene increases by smaller particle sizes of TiO2.The elongational viscosity of Polypropylene melts increase with additive amounts of the nano-scale TiO2 particles and volume flow rate increase. But the elongational viscosity of Polypropylene melts decrease with the temperature and extracted speed tension increased. The DSC test shows that the melting temperature of Polypropylene fibers doesn’t change. The TGA test shows that the thermal stability properties of nano-scale TiO2/Polypropylene fibers increased. From the observed AFM results, it shows that the surface of Polypropylene fibers covered TiO2 particles, and these particles agglutinated.
Book chapters on the topic "Fiber elongation"
1
Naoumkina, Marina. "Advances in Understanding of Cotton Fiber Cell Differentiation and Elongation." In Cotton Fiber: Physics, Chemistry and Biology, 179–91. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-030-00871-0_9.
Full text
2
Stiff, Michael R., J. Rich Tuttle, Benjamin P. Graham, and Candace H. Haigler. "Cotton Fiber BiotechnologyCotton Fiber Biotechnology : Potential Controls and Transgenic Improvement of Elongation and Cell Wall Thickening." In Sustainable Development and Biodiversity, 127–53. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-44570-0_8.
Full text
3
Schmidt, Valentin, and Andreas Pott. "Increase of Position Accuracy for Cable-Driven Parallel Robots Using a Model for Elongation of Plastic Fiber Ropes." In New Trends in Mechanism and Machine Science, 335–43. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-44156-6_34.
Full text
4
Higashi-Fujime, S. "Actin-Induced Elongation of Fibers Composed of Cytoplasmic Membrane from Nitella." In Protoplasma, 27–36. Vienna: Springer Vienna, 1988. http://dx.doi.org/10.1007/978-3-7091-9011-1_4.
Full text
5
Kotsilkova, R., M. Okamoto, H. Taguchi, N. Sato, H. Sato, and T. Kotaka. "Shear and Elongational Flow of Smectite/PMMA Hybrids and Glass Fiber/PMMA Composites." In Progress and Trends in Rheology V, 398–99. Heidelberg: Steinkopff, 1998. http://dx.doi.org/10.1007/978-3-642-51062-5_191.
Full text
6
Berlin, A. A., E. S. Zelenski, L. V. Puchkov, A. M. Kuperman, and S. L. Bazhenov. "On the Effect of the Yarn Rupture Elongation Scatter on the Strength of Unidirectional Organic Fibre Reinforced Plastics." In Polymer Composites, edited by Blahoslav Sedlácek, 487–96. Berlin, Boston: De Gruyter, 1986. http://dx.doi.org/10.1515/9783110856934-044.
Full text
7
LETOURNEAU, PAUL C. "Regulation of Nerve Fiber Elongation during Embryogenesis." In Development Neuropsychobiology, 33–71. Elsevier, 1986. http://dx.doi.org/10.1016/b978-0-12-300270-9.50008-0.
Full text
8
LETOURNEAU, PAUL C. "Regulation of Nerve Fiber Elongation during Embryogenesis." In Developmental Neuropsychobiology, 33–71. Elsevier, 1986. http://dx.doi.org/10.1016/b978-0-12-300271-6.50008-1.
Full text
9
S. Kamburova, Venera, Ilkhom B. Salakhutdinov, Shukhrat E. Shermatov, Zabardast T. Buriev, and Ibrokhim Y. Abdurakhmonov. "Cotton as a Model for Polyploidy and Fiber Development Study." In Model Organisms in Plant Genetics [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.99568.
Full textAbstract:
Cotton is one of the most important crops in the world. The Gossypium genus is represented by 50 species, divided into two levels of ploidy: diploid (2n = 26) and tetraploid (2n = 52). This diversity of Gossypium species provides an ideal model for studying the evolution and domestication of polyploids. In this regard, studies of the origin and evolution of polyploid cotton species are crucial for understanding the ways and mechanisms of gene and genome evolution. In addition, studies of polyploidization of the cotton genome will allow to more accurately determine the localization of QTLs that determine fiber quality. In addition, due to the fact that cotton fibers are single trichomes originating from epidermal cells, they are one of the most favorable model systems for studying the molecular mechanisms of regulation of cell and cell wall elongation, as well as cellulose biosynthesis.
10
Lucchesi, John C. "Epigenetic chromatin changes and the transcription cycle." In Epigenetics, Nuclear Organization & Gene Function, 57–68. Oxford University Press, 2019. http://dx.doi.org/10.1093/oso/9780198831204.003.0005.
Full textAbstract:
In order to allow transcription to occur, the association of DNA with histone octamers and the compacted physical state of the chromatin fiber must be modified by the opportunistic binding of pioneer transcription factors to their cognate DNA binding sites. Once bound, pioneer factors recruit chromatin remodelers and histone-modifying enzymes for the purpose of repositioning nucleosomes and exposing regulatory regions (enhancers and gene promoters) to the components necessary for the initiation of transcription. Histone modifications, such as acetylation, methylation and ubiquitination, and the dynamic phosphorylation of specific amino acids on the major RNA polymerase II subunit activate transcription and attract the factors necessary to eliminate the pausing that normally occurs soon after initiation. Further histone modifications and the replacement of certain core histones by histone variants facilitate transcript elongation and termination. Two additional major epigenetic modifications that impact the process of transcription consist of the action of non-coding RNAs and DNA methylation.
Conference papers on the topic "Fiber elongation"
1
Szustakowski, Mieczyslaw, Norbert Palka, and Bogdan Kizlik. "Contrastometric Fiber Optic Elongation Sensor." In 2006 International Conference - Modern Problems of Radio Engineering, Telecommunications, and Computer Science. IEEE, 2006. http://dx.doi.org/10.1109/tcset.2006.4404456.
Full text
2
Yokohama, I., K. Okamoto, and J. Noda. "Fiber Coupler Fabrication with Automatic Fusion-Elongation Processes." In Optical Fiber Sensors. Washington, D.C.: OSA, 1986. http://dx.doi.org/10.1364/ofs.1986.108.
Full text
3
Pérez-Sánchez, Grethell G., José A. Mejía-Islas, Edgar A. Andrade-González, and José R. Pérez-Torres. "Elongation-based fiber optic tunable filter." In Infrared Sensors, Devices, and Applications VII, edited by Paul D. LeVan, Ashok K. Sood, Priyalal Wijewarnasuriya, and Arvind I. D'Souza. SPIE, 2017. http://dx.doi.org/10.1117/12.2274650.
Full text
4
Francois, Michel, Peter Davies, Francois Grosjean, and Franck Legerstee. "Modelling fiber rope load-elongation properties - Polyester and other fibers." In Offshore Technology Conference. Offshore Technology Conference, 2010. http://dx.doi.org/10.4043/20846-ms.
Full text
5
Qian, Jingren, and Jiatong Luo. "Elongation characteristics of fused taped optical fiber loop reflectors." In Asia-Pacific Optical and Wireless Communications 2002, edited by WeiSheng Hu, Shoichi Sudo, and Peter Kaiser. SPIE, 2002. http://dx.doi.org/10.1117/12.480596.
Full text
6
Mikel, Bretislav, Martin Cizek, Milan Holik, and Ondrej Cip. "Calibration of elongation of fiber Bragg gratings by laser interferometer." In Sixth International Symposium on Precision Mechanical Measurements, edited by Shenghua Ye and Yetai Fei. SPIE, 2013. http://dx.doi.org/10.1117/12.2035731.
Full text
7
Montero, D. S., J. C. Torres, J. Zahr-Viñuelas, J. L. Pérez Castellanos, and C. Vázquez. "Effects of elongation on polymer optical fiber power losses for sensing purposes." In OFS2014 23rd International Conference on Optical Fiber Sensors, edited by José M. López-Higuera, Julian D. C. Jones, Manuel López-Amo, and José L. Santos. SPIE, 2014. http://dx.doi.org/10.1117/12.2059276.
Full text
8
Kashiwagi, Ken, Yoshitake Usui, Yutaka Owada, Yosuke Tanaka, and Takashi Kurokawa. "Measurement Range Elongation of Brillouin Fiber Sensor Using Optical Frequency Comb." In Frontiers in Optics. Washington, D.C.: OSA, 2012. http://dx.doi.org/10.1364/fio.2012.fm4h.3.
Full text
9
Liu, Chun-Yuan, Wei-Ren Chang, Wei-Bor Tsai, and Pen-Hsiu Grace Chao. "Effect of Solvent on Electrospun PLLA Fiber Mechanical Characteristics and Ligament Fibroblast Responses." In ASME 2010 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2010. http://dx.doi.org/10.1115/sbc2010-19339.
Full textAbstract:
Due to the poor healing ability of anterior cruciate ligaments (ACL), surgical interventions with graft materials are often needed to reconstruct the knee joint. Electrospinning is widely utilized to manufacture highly aligned fibrous materials. When cultured on such substrates, ligament fibroblasts are known to exhibit elongation and enhanced collagen production [1, 2]. Poly-L-lactic-acid (PLLA) is a popular biocompatible material with high mechanical strength, and is most often used in electrospinning with chloroform as solvent. Hexafluoropropanol (HFP), another solvent, generates more uniform and consistent electrospun PLLA fibers. In this study, we investigated the effects of electrospun PLLA fiber scaffolds using different solvent on ligament tissue engineering. PLLA fibers electrospun with chloroform or HFP were compared for their structure and mechanical characteristics. We also investigated their effects on ligament cell morphology and proliferation. Further analysis of composite fiber bilayers were also performed [3].
10
Burns, James S., and Constantin Scheder. "A Non-Continuum Model of Aligned, Long Fiber Composite Textile Preform Tensile Response." In ASME 2004 International Mechanical Engineering Congress and Exposition. ASMEDC, 2004. http://dx.doi.org/10.1115/imece2004-60761.
Full textAbstract:
Stretch-broken fiber preforms provide composites with post-formable characteristics that may reduce the costs of manufacturing complex shapes. Research into fiber preform production methods provides a fiber length and dispersion predictor that is then used to predict forming inputs required to excite tensile elongation of the preform under the influence of various boundary conditions common to sheet-based forming. Fiber behavior is discussed separately from the influence of liquid-phase matrix material. A comparison is made between model results and tensile response measurements of performs for polyarylate-matrix composites.