Recent decades have seen a substantial increase in interest in research on natural fibres that is aligned with sustainable development goals(SDGs).Due to their renewable resources and biodegradability,natural fiberrei...Recent decades have seen a substantial increase in interest in research on natural fibres that is aligned with sustainable development goals(SDGs).Due to their renewable resources and biodegradability,natural fiberreinforced composites have been investigated as a sustainable alternative to synthetic materials to reduce the usage of hazardous waste and environmental pollution.Among the natural fibre,jute fibre obtained from a bast plant has an increasing trend in the application,especially as a reinforcement material.Numerous research works have been performed on jute fibre with regard to reinforced thermoset and thermoplastic composites.Nevertheless,current demands on sustainable materials have required new developments in thermoplastic composites.In this paper,the author reviews jute plants as reinforcement materials for thermoplastic matrix polymers.This review provides an overview of the sustainability of jute plants as reinforcement material for thermoplastic matrix polymers.The overview on jute based thermoplastic composites focused on the thermal behavior and mechanical properties.Apart from physical,chemical,and mechanical properties,the study also covers the current and perspectives for future research challenges faced by the researchers on jute fibre reinforced thermoplastic composites.展开更多
To solve the problems of a few optical fibre line fault samples and the inefficiency of manual communication optical fibre fault diagnosis,this paper proposes a communication optical fibre fault diagnosis model based ...To solve the problems of a few optical fibre line fault samples and the inefficiency of manual communication optical fibre fault diagnosis,this paper proposes a communication optical fibre fault diagnosis model based on variational modal decomposition(VMD),fuzzy entropy(FE)and fuzzy clustering(FC).Firstly,based on the OTDR curve data collected in the field,VMD is used to extract the different modal components(IMF)of the original signal and calculate the fuzzy entropy(FE)values of different components to characterize the subtle differences between them.The fuzzy entropy of each curve is used as the feature vector,which in turn constructs the communication optical fibre feature vector matrix,and the fuzzy clustering algorithm is used to achieve fault diagnosis of faulty optical fibre.The VMD-FE combination can extract subtle differences in features,and the fuzzy clustering algorithm does not require sample training.The experimental results show that the model in this paper has high accuracy and is relevant to the maintenance of communication optical fibre when compared with existing feature extraction models and traditional machine learning models.展开更多
New fibres continue to be developed for a wide range of technical textile applications.Currently,they include fibres based on organic or recycled feedstocks to meet sustainability targets and others with new functiona...New fibres continue to be developed for a wide range of technical textile applications.Currently,they include fibres based on organic or recycled feedstocks to meet sustainability targets and others with new functional properties for advanced high performance applications.Many of them were showcased at the forthcoming Techtextil 2024 exhibition which takes place in Frankfurt,Germany,from April 23-26.The development of specific multifilaments,monofilaments and nonwovens for niche fibre applications–over 70 to date–is very much the specialist field of BTMA member Fibre Extrusion Technologies(FET),along with designing the bespoke fibre extrusion and spunbond and meltblown nonwoven systems to successfully produce them.展开更多
Tetrahydrofuran(THF) extract of coal tar pitch(CTP) was used instead of blending CTP with pretreated pyrolysis fuel oil to prepare an isotropic pitch precursor with excellent spinnability for general-purpose carbon fi...Tetrahydrofuran(THF) extract of coal tar pitch(CTP) was used instead of blending CTP with pretreated pyrolysis fuel oil to prepare an isotropic pitch precursor with excellent spinnability for general-purpose carbon fibre through bromination-dehydrobromination. The feasibility and effectiveness of synthesising an isotropic pitch precursor derived from THF-soluble(CTP-THFs) is demonstrated in this study.The results show that CTP-THFs contains more light components than CTP;CTP-THFs and CTP monomer proportions were 62.52% and 45.32%, respectively. However, based on comparisons of CTP-THFsBr0 and CTPBr0 characterisations, CTP-THFs exhibits better polycondensation than CTP. Bromination-dehydrobro mination promotes polycondensation of pitch precursors, leading to greater carbon aromaticity in CTP-THFsBr5, CTP-THFsBr10, and CTP-THFsBr15 than that in CTP-THFsBr0 and CTPBr0. CTP-THFsBr5 and CTP-THFsBr10 have excellent spinnability even with softening points as high as 230 ℃. The pericondensed carbon and carbon aromaticity of CTP-THFsBr5 and CTP-THFsBr10 are high owing to the higher degree of polycondensation;however, they still possess a more linear molecular structure. The as-prepared carbon fibre exhibits homogeneity and uniformity, and the mechanical performance is comparable with that of commercial general-purpose carbon fibre products.展开更多
Fibre can enhance the mechanical properties of cement-based composites,but fibre also degrades their workability.However,the quantitative effects of fiber content and length-diameter ratio on alkali-activated material...Fibre can enhance the mechanical properties of cement-based composites,but fibre also degrades their workability.However,the quantitative effects of fiber content and length-diameter ratio on alkali-activated materials are still unclear.Various aspect ratio,volume fraction of polyvinyl alcohol fibre(PVAF),and various water-binder ratio were employed to prepare a total of 26 groups of fibre reinforced alkali-activated composite(FRAAC).The influence of PVAF fibre factor(product of fiber volume fraction and length-diameter ratio)on flowability,compactness,strength,and crack fractal dimension of FRAAC was researched.The influence of water-binder ratio on the plastic viscosity of FRAAC was more significant than that on the yield stress.When fibre factor was lower than critical value of 150,the influence of fibres could be overlooked.The reason was that the space between fibres was distant,so the flowability of FRAAC was not impacted by PVAF.At this time,fibres were challenging to restrict the cracks in matrix and increase their mechanical properties.When fibre factor was higher than critical value 150 and lower than density packing value 450,the flexural strength,compressive strength and crack fractal dimension of FRAAC were considerably enhanced,and the FRAAC could still flow easily under dead weight.When fibre factor were above 450,noteworthy fibre balling considerably decreased the flowability,leading to poor solidity and reduced compressive strength.Hence,the ideal content of PVAF in alkali activated composite is between 150/(l/d)and 450/(l/d).展开更多
Results The population had large variations for lint yield,fibre properties,predicted yarn properties,and composite fibre quality values.Lint yield with all fibre quality traits was not correlated.When the selection w...Results The population had large variations for lint yield,fibre properties,predicted yarn properties,and composite fibre quality values.Lint yield with all fibre quality traits was not correlated.When the selection was conducted first to keep those with improved fibre quality,and followed for high yields,a large proportion in the resultant populations was the same between selections based on Cottonspec predicted yarn quality and HVI-measured fibre properties.They both exceeded the selection based on FQI and Background The approach of directly testing yarn quality to define fibre quality breeding objectives and progress the selection is attractive but difficult when considering the need for time and labour.The question remains whether yarn prediction tools from textile research can serve as an alternative.In this study,using a dataset from three seasons of field testing recombinant inbred line population,Cottonspec,a software developed by the Commonwealth Scientific and Industrial Research Organisation(CSIRO)for predicting ring spun yarn quality from fibre properties measured by High Volume Instrument(HVI),was used to select improved fibre quality and lint yield in the population.The population was derived from an advanced generation inter-crossing of four CSIRO conventional commercial varieties.The Cottonspec program was able to provide an integrated index of the fibre qualities affecting yarn properties.That was compared with selection based on HVI-measured fibre properties,and two composite fibre quality variables,namely,fibre quality index(FQI),and premium and discount(PD)points.The latter represents the net points of fibre length,strength,and micronaire based on the Premiums and Discounts Schedule used in the market while modified by the inclusion of elongation.PD points.Conclusions The population contained elite segregants with improved yield and fibre properties,and Cottonspec predicted yarn quality is useful to effectively capture these elites.There is a need to further develop yarn quality prediction tools through collaborative efforts with textile mills,to draw better connectedness between fibre and yarn quality.This connection will support the entire cotton value chain research and evolution.展开更多
The study of a flexible body immersed in a flowing medium is one of the best way to find its aerodynamic shape.This Letter revisited the problem that was first studied by Alben et al.(Nature 420,479–481,2002).To dete...The study of a flexible body immersed in a flowing medium is one of the best way to find its aerodynamic shape.This Letter revisited the problem that was first studied by Alben et al.(Nature 420,479–481,2002).To determine the aerodynamic shape of the fibre,a simpler approach is proposed.A universal drag scaling law is obtained and the universality of the Alben-Shelley-Zhang scaling law is confirmed by using dimensional analysis.A complete Maple code is provided for finding aerodynamic shape of the fibre in the flowing medium.展开更多
Background Gossypium barbadense L.has specific fibre in terms of its length,strength,and fineness,and known as extra-long staple(ELS) cotton,Sea–Island cotton,or Egyptian cotton.Narrow genetic base with less genetic ...Background Gossypium barbadense L.has specific fibre in terms of its length,strength,and fineness,and known as extra-long staple(ELS) cotton,Sea–Island cotton,or Egyptian cotton.Narrow genetic base with less genetic variability is observed in G.barbadense germplasm.Hence,this study was aimed to evaluate the genetic variability present in 108 germplasm accessions of G.barbadense and to identify the superior genotypes based on the fibre traits.Results We evaluated 108 accessions for five fibre quality traits along with three checks in augmented block design.All fibre traits showed significant differences among genotypes,indicating that there is genetic potential for improvement.Fibre strength and micronaire(MIC) showed high phenotypic and genotypic coefficients of variation.High heritability combined with high genetic advance as percentage of mean(GAM) was recorded for fibre length,strength,and micronaire.Fibre strength and fibre length were significantly correlated with each other,while both showed negative correlation with micronaire.Principal component analysis and Biplot analysis showed that uniformity index discriminated all the genotypes in higher level,while fibre length and strength were medium in discrimination power.Biplot revealed genotypes DB 16,EC959191,GSB 39,ARBB 20,5746U,EA 203,and EA 201 were genetically diverse.Hierarchal cluster analysis based on unweighted paired group method using arithmetic average(UPGMA) grouped the genotypes into four clusters,with each cluster consisting of 4,18,48,and 38 genotypes,respectively.Conclusion Among the genotypes,34 for fibre length(> 35 mm),18 for fibre strength(> 40.4 g·tex^(-1)) and 66 for micronaire(3.7-4.2,A grade) were identified as potential accessions based on their superiority.The superior fibre genotypes identified in this study are potential lines for the ELS cotton breeding program.展开更多
Natural fibre reinforced polymer composite(NFRPC)materials are gaining popularity in the modern world due to their eco-friendliness,lightweight nature,life-cycle superiority,biodegradability,low cost,and noble mechani...Natural fibre reinforced polymer composite(NFRPC)materials are gaining popularity in the modern world due to their eco-friendliness,lightweight nature,life-cycle superiority,biodegradability,low cost,and noble mechanical properties.Due to the wide variety of materials available that have comparable attributes and satisfy the requirements of the product design specification,material selection has become a crucial component of design for engineers.This paper discusses the study’s findings in choosing the suitable thermoplastic matrices of Natural Fibre Composites for Cyclist Helmet utilising the DMAIC,and GRA approaches.The results are based on integrating two decision methods implemented utilising two distinct decision-making approaches:qualitative and quantitative.This study suggested thermoplastic polyethylene as a particularly ideal matrix in composite cyclist helmets during the selection process for the best thermoplastic matrices material using the 6σtechnique,with the decision based on the highest performance,the lightest weight,and the most environmentally friendly criteria.The DMAIC and GRA approach significantly influenced the material selection process by offering different tools for each phase.In the future study,selection technique may have been more exhaustive if more information from other factors had been added.展开更多
In order to examine the biaxial compression-compression properties of rubber fibre reinforced concrete(RFRC),an experimental study on RFRC under different lateral compressive stresses was carried out by considering di...In order to examine the biaxial compression-compression properties of rubber fibre reinforced concrete(RFRC),an experimental study on RFRC under different lateral compressive stresses was carried out by considering different rubber replacement rates and polypropylene fibre contents.The failure modes and mechanical property parameters of different RFRC working conditions were obtained from the experiment to explore the effects of rubber replacement rate and polypropylene fibre content on the biaxial compression-compression properties of RFRC.The following conclusions were drawn.Under the influence of lateral compressive stress,the biaxial compression-compression failure mode gradually developed from a columnar pattern to a flaky pattern,suggesting that the incorporation of rubber and polypropylene fibres into the concrete resulted in a significant change in the development of cracks.For different rubber replacement rates and polypropylene fibre contents,the vertical compressive stress exhibited the same developing trend under the influence of lateral compressive stress.Specifically,the lateral compressive stress imposed the minimum effect on the vertical compressive stress when the rubber replacement rate and polypropylene fibre content were 20%and 0.4%,respectively,and imposed the maximum effect when the rubber replacement rate and polypropylene fibre content were 20%and 0%,respectively.With the increase of rubber replacement rate,the vertical peak stress was significantly reduced,which implies that an appropriate amount of polypropylene fibres can increase the vertical peak stress to a certain extent.Then,the biaxial compression-compression mechanism of RFRC was analysed from the microscopic level by using scanning electron microscope(SEM).Meanwhile,based on Kupfer’s biaxial compression-compression failure criterion and the octahedral stress space,a biaxial compression-compression failure criterion for RFRC was proposed,which was proven to have good applicability.The research results of this study provide important theoretical basis for the engineering application and development of RFRC.展开更多
Naturalfibre as a reinforcing agent has been widely used in many industrial applications.Nevertheless,several factors need to be considered,such as the size and weight percentage of thefibre used in binding.Using fused ...Naturalfibre as a reinforcing agent has been widely used in many industrial applications.Nevertheless,several factors need to be considered,such as the size and weight percentage of thefibre used in binding.Using fused deposition modelling(FDM),this factor was investigated by varying the size of naturalfibre as the responding variable with afixed weight percentage of kenaffibre.The process of modifying the naturalfibre in terms of size might increase the dispersion of kenaffibre in the polymer matrix and increase the adhesion bonding between thefibre and matrix of composites,subsequently improving the interfacial bonding between these two phases.In this paper,the effect offibre size was evaluated by performing the mechanical test,Scanning Electron Micrograph(SEM)to observe the morphology of the composites,and also by surface analysis.The surface roughness was visualised using a 3D profilometer and thefigure was illustrated as colour shading in the image.The composite withfibre size≤100μm displayed better tensile andflexural strength,compared to other sizes.In conclusion,by reducing the size of thefibre,the composites could develop high strength performance for industrial applications.展开更多
The advancement and novel technologies in materials science have been steadily growing toward adopting ethical practices.To reduce the stress on the environment the producers integrate novel materials to extend tradit...The advancement and novel technologies in materials science have been steadily growing toward adopting ethical practices.To reduce the stress on the environment the producers integrate novel materials to extend traditional functionality.They develop modern fibers that are eco-friendly,light,resilient,mechanically flexible,and easy to process.Moreover,novel fabrics are acquiring unique properties such as sensory capabilities,electrical conductivity,and data transmission.Cloths with characteristics such as hydrophobic cotton,plant-based textiles,antimicrobial fabrics,and shape memory polymers show versatility in textile innovations.Overall,these textile innovations provide sustainable alternatives,which are commercially viable and suitable for large-scale production.展开更多
Fibres from a variety of sources are a common constituent of pig feeds. They provide a means to utilise locallyproduced plant materials which are often a by-product of the food or drink industry. The value of a high f...Fibres from a variety of sources are a common constituent of pig feeds. They provide a means to utilise locallyproduced plant materials which are often a by-product of the food or drink industry. The value of a high fibre diet in terms of producing satiety has long been recognised. However the addition of fibre can reduce feed intake, which is clearly detrimental during stages of the production cycle when nutrient needs are high, for example in growing piglets and during lactation. More recently, fibre has been found to promote novel benefits to pig production systems,particularly given the reduction in antimicrobial use world-wide, concern for the welfare of animals fed a restricted diet and the need to ensure that such systems are more environmentally friendly. For example, inclusion of dietary fibre can alter the gut microbiota in ways that could reduce the need for antibiotics, while controlled addition of certain fibre types may reduce nitrogen losses into the environment and so reduce the environmental cost of pig production.Of particular potential value is the opportunity to use crude fibre concentrates as ’functional’ feed additives to improve young pig growth and welfare. Perhaps the greatest opportunity for the use of high fibre diets is to improve the reproductive efficiency of pigs. Increased dietary fibre before mating improves oocyte maturation, prenatal survival and litter size; providing a consumer-acceptable means of increasing the amount of saleable meat produced per sow. The mechanisms responsible for these beneficial effects remain to be elucidated. However, changes in plasma and follicular fluid concentrations of key hormones and metabolites, as well as effects of the hypothalamic satiety centre on gonadotrophin secretion and epigenetic effects are strong candidates.展开更多
The dynamical behaviour of the erbium-doped fibre single-ring laser with an optical delay feedback is discussed. Simulation shows that as the delay rate increases, the lasing light displays period-doubling which leads...The dynamical behaviour of the erbium-doped fibre single-ring laser with an optical delay feedback is discussed. Simulation shows that as the delay rate increases, the lasing light displays period-doubling which leads to chaos and via reverse period-doubling route returns from chaos to periodic. At a particular delay rate the intermittently chaotic route to chaos is also observed. The identical synchronization based on chaos in this ring laser is demonstrated by numerical simulation.展开更多
Background: Exogenous melatonin could induce cashmere growth. However, induced growth of cashmere fleece by melatonin implants cannot be combined with the typical growth, resulting in earlier shedding followed by ano...Background: Exogenous melatonin could induce cashmere growth. However, induced growth of cashmere fleece by melatonin implants cannot be combined with the typical growth, resulting in earlier shedding followed by another cycle of cashmere growth. To address this issue, we examine the effects on the cashmere yield, fibre characteristics, and the growth and reproductive performance of cashmere goats of planned administration of melatonin. Methods: Eighteen half-sib, female goats were assigned to two treatments (n = 9) including a control and a treatment where melatonin (2 mg/kg BW) was implanted at the end of April and end of June. Cashmere growth and shedding were observed for approximately ] year following implantation. Fibre samples were collected monthly to determine cumulative cashmere length. Initiation and cessation dates for cashmere growth as well as the rate of cashmere growth were calculated. Cashmere yield, weight gain of dam, kidding date, litter size, and birth weight were also recorded. Results: Melatonin implantation increased cashmere yield by 34.5 % (control 553.7 g vs. melatonin 745.0 g; P〈 0.01), cashmere length by 21.3 % (control 95.2 mm vs. melatonin 115.4 mm; P 〈 0.01), and decreased fibre diameter by 4.4 % (control 14.6 pm vs. melatonin 14.0 IJm; P 〈 0.03). In melatonin-treated goats, the average initiation date was earlier than in control goats (May 18, 2013 vs. July 2, 20]3; P〈 0.01) but there was a similar cessation date (March 22, 2014 vs. March 27, 2014). Consequently, the duration of cashmere growth was longer in melatonin-treated goats than in control goats (307 vs.270 days; P 〈 0.01). The final BW, average daily gain, kidding date, litter size, and birth weight were not influenced by melatonin implantation. Conclusions: These data indicate that melatonin implantation (2 mg/kg BW) on two occasions (late April and June) increased cashmere yield by combining the induced growth of cashmere fleece with the typical growth and decreased the fibre diameter without changing dam growth rate or reproductive performance.展开更多
Geotechnical stability is a major concern for the long-term safety and integrity of underground infrastructures such as tunnels, railway stations, mine shafts and hydraulic power chambers. An effective geotechnical mo...Geotechnical stability is a major concern for the long-term safety and integrity of underground infrastructures such as tunnels, railway stations, mine shafts and hydraulic power chambers. An effective geotechnical monitoring system is able to provide adequate warning to underground personnel prior to any unexpected major geotechnical failure. This paper reviews the conventional geotechnical monitoring sensors and the emerging Fibre Optic Sensing(FOS) techniques, pointing out their unique features and major differences. Recent advances in various FOS based monitoring systems, including Brillouin time domain distributed optical sensors and fibre Bragg grating(FBG) sensors, are investigated through a critical review of the laboratory studies and field applications used for underground geotechnical monitoring. Particular emphasis is given to fibre packaging, temperature compensation, installation methods and instrumentation performance in the underground environment. A detailed discussion of the advantages and limitations of each FOS monitoring system is also presented in this paper.展开更多
Based on the rate equations describing the erbium-doped fluoride glass (ZBLAN) fibre lasers with different pumping configurations being taken into account, this paper presents theoretical calculations related to the...Based on the rate equations describing the erbium-doped fluoride glass (ZBLAN) fibre lasers with different pumping configurations being taken into account, this paper presents theoretical calculations related to the dynamic population density and the operation performance of a high power mid-infrared all-fibre erbium-doped ZBLAN fibre laser. It shows that the ground-state absorption, excited-state absorption and energy-transfer-upconversion processes co-exist and produce a population balance, causing the laser to operate stably at a continuous wave state. A good agreement between the theoretical results and recent experimental measurement is obtained. Furthermore, the laser structure parameters including fibre length, reflectance of output fibre Bragg grating and pumping configurations are quantitatively optimised to achieve the best performance. The results show, as expected, that the slope efficiency of the fibre laser can be improved significantly through optimisation, which then provides an important guide for the design of high-performance mid-infrared erbium-doped ZBLAN fibre lasers.展开更多
文摘Recent decades have seen a substantial increase in interest in research on natural fibres that is aligned with sustainable development goals(SDGs).Due to their renewable resources and biodegradability,natural fiberreinforced composites have been investigated as a sustainable alternative to synthetic materials to reduce the usage of hazardous waste and environmental pollution.Among the natural fibre,jute fibre obtained from a bast plant has an increasing trend in the application,especially as a reinforcement material.Numerous research works have been performed on jute fibre with regard to reinforced thermoset and thermoplastic composites.Nevertheless,current demands on sustainable materials have required new developments in thermoplastic composites.In this paper,the author reviews jute plants as reinforcement materials for thermoplastic matrix polymers.This review provides an overview of the sustainability of jute plants as reinforcement material for thermoplastic matrix polymers.The overview on jute based thermoplastic composites focused on the thermal behavior and mechanical properties.Apart from physical,chemical,and mechanical properties,the study also covers the current and perspectives for future research challenges faced by the researchers on jute fibre reinforced thermoplastic composites.
基金This paper is supported by State Grid Gansu Electric Power Company Science and Technology Project(20220515003).
文摘To solve the problems of a few optical fibre line fault samples and the inefficiency of manual communication optical fibre fault diagnosis,this paper proposes a communication optical fibre fault diagnosis model based on variational modal decomposition(VMD),fuzzy entropy(FE)and fuzzy clustering(FC).Firstly,based on the OTDR curve data collected in the field,VMD is used to extract the different modal components(IMF)of the original signal and calculate the fuzzy entropy(FE)values of different components to characterize the subtle differences between them.The fuzzy entropy of each curve is used as the feature vector,which in turn constructs the communication optical fibre feature vector matrix,and the fuzzy clustering algorithm is used to achieve fault diagnosis of faulty optical fibre.The VMD-FE combination can extract subtle differences in features,and the fuzzy clustering algorithm does not require sample training.The experimental results show that the model in this paper has high accuracy and is relevant to the maintenance of communication optical fibre when compared with existing feature extraction models and traditional machine learning models.
文摘New fibres continue to be developed for a wide range of technical textile applications.Currently,they include fibres based on organic or recycled feedstocks to meet sustainability targets and others with new functional properties for advanced high performance applications.Many of them were showcased at the forthcoming Techtextil 2024 exhibition which takes place in Frankfurt,Germany,from April 23-26.The development of specific multifilaments,monofilaments and nonwovens for niche fibre applications–over 70 to date–is very much the specialist field of BTMA member Fibre Extrusion Technologies(FET),along with designing the bespoke fibre extrusion and spunbond and meltblown nonwoven systems to successfully produce them.
基金the financial support provided by the National Natural Science Foundation of China (22008254)the Fundamental Research Funds for the Central Universities (2020XJHH01)+1 种基金the National Training Program of Innovation and Entrepreneurship for Undergraduates (C202003309)China University of Mining and Technology (Beijing) Yueqi Outstanding Scholar Project (2020JCB02)。
文摘Tetrahydrofuran(THF) extract of coal tar pitch(CTP) was used instead of blending CTP with pretreated pyrolysis fuel oil to prepare an isotropic pitch precursor with excellent spinnability for general-purpose carbon fibre through bromination-dehydrobromination. The feasibility and effectiveness of synthesising an isotropic pitch precursor derived from THF-soluble(CTP-THFs) is demonstrated in this study.The results show that CTP-THFs contains more light components than CTP;CTP-THFs and CTP monomer proportions were 62.52% and 45.32%, respectively. However, based on comparisons of CTP-THFsBr0 and CTPBr0 characterisations, CTP-THFs exhibits better polycondensation than CTP. Bromination-dehydrobro mination promotes polycondensation of pitch precursors, leading to greater carbon aromaticity in CTP-THFsBr5, CTP-THFsBr10, and CTP-THFsBr15 than that in CTP-THFsBr0 and CTPBr0. CTP-THFsBr5 and CTP-THFsBr10 have excellent spinnability even with softening points as high as 230 ℃. The pericondensed carbon and carbon aromaticity of CTP-THFsBr5 and CTP-THFsBr10 are high owing to the higher degree of polycondensation;however, they still possess a more linear molecular structure. The as-prepared carbon fibre exhibits homogeneity and uniformity, and the mechanical performance is comparable with that of commercial general-purpose carbon fibre products.
基金funding of Henan Province Transportation Science and Technology Plan Project(2021J3).
文摘Fibre can enhance the mechanical properties of cement-based composites,but fibre also degrades their workability.However,the quantitative effects of fiber content and length-diameter ratio on alkali-activated materials are still unclear.Various aspect ratio,volume fraction of polyvinyl alcohol fibre(PVAF),and various water-binder ratio were employed to prepare a total of 26 groups of fibre reinforced alkali-activated composite(FRAAC).The influence of PVAF fibre factor(product of fiber volume fraction and length-diameter ratio)on flowability,compactness,strength,and crack fractal dimension of FRAAC was researched.The influence of water-binder ratio on the plastic viscosity of FRAAC was more significant than that on the yield stress.When fibre factor was lower than critical value of 150,the influence of fibres could be overlooked.The reason was that the space between fibres was distant,so the flowability of FRAAC was not impacted by PVAF.At this time,fibres were challenging to restrict the cracks in matrix and increase their mechanical properties.When fibre factor was higher than critical value 150 and lower than density packing value 450,the flexural strength,compressive strength and crack fractal dimension of FRAAC were considerably enhanced,and the FRAAC could still flow easily under dead weight.When fibre factor were above 450,noteworthy fibre balling considerably decreased the flowability,leading to poor solidity and reduced compressive strength.Hence,the ideal content of PVAF in alkali activated composite is between 150/(l/d)and 450/(l/d).
基金funded through Cotton Breeding Australia,a Joint Venture between CSIRO and Cotton Seed Distributors(Wee Waa,NSW 2388,Australia)。
文摘Results The population had large variations for lint yield,fibre properties,predicted yarn properties,and composite fibre quality values.Lint yield with all fibre quality traits was not correlated.When the selection was conducted first to keep those with improved fibre quality,and followed for high yields,a large proportion in the resultant populations was the same between selections based on Cottonspec predicted yarn quality and HVI-measured fibre properties.They both exceeded the selection based on FQI and Background The approach of directly testing yarn quality to define fibre quality breeding objectives and progress the selection is attractive but difficult when considering the need for time and labour.The question remains whether yarn prediction tools from textile research can serve as an alternative.In this study,using a dataset from three seasons of field testing recombinant inbred line population,Cottonspec,a software developed by the Commonwealth Scientific and Industrial Research Organisation(CSIRO)for predicting ring spun yarn quality from fibre properties measured by High Volume Instrument(HVI),was used to select improved fibre quality and lint yield in the population.The population was derived from an advanced generation inter-crossing of four CSIRO conventional commercial varieties.The Cottonspec program was able to provide an integrated index of the fibre qualities affecting yarn properties.That was compared with selection based on HVI-measured fibre properties,and two composite fibre quality variables,namely,fibre quality index(FQI),and premium and discount(PD)points.The latter represents the net points of fibre length,strength,and micronaire based on the Premiums and Discounts Schedule used in the market while modified by the inclusion of elongation.PD points.Conclusions The population contained elite segregants with improved yield and fibre properties,and Cottonspec predicted yarn quality is useful to effectively capture these elites.There is a need to further develop yarn quality prediction tools through collaborative efforts with textile mills,to draw better connectedness between fibre and yarn quality.This connection will support the entire cotton value chain research and evolution.
基金supported by Xi’an University of Architecture and Technology(Grant No.002/2040221134).
文摘The study of a flexible body immersed in a flowing medium is one of the best way to find its aerodynamic shape.This Letter revisited the problem that was first studied by Alben et al.(Nature 420,479–481,2002).To determine the aerodynamic shape of the fibre,a simpler approach is proposed.A universal drag scaling law is obtained and the universality of the Alben-Shelley-Zhang scaling law is confirmed by using dimensional analysis.A complete Maple code is provided for finding aerodynamic shape of the fibre in the flowing medium.
基金supported by ICAR-Central Institute for Cotton Research, Regional Station, Coimbatore, India。
文摘Background Gossypium barbadense L.has specific fibre in terms of its length,strength,and fineness,and known as extra-long staple(ELS) cotton,Sea–Island cotton,or Egyptian cotton.Narrow genetic base with less genetic variability is observed in G.barbadense germplasm.Hence,this study was aimed to evaluate the genetic variability present in 108 germplasm accessions of G.barbadense and to identify the superior genotypes based on the fibre traits.Results We evaluated 108 accessions for five fibre quality traits along with three checks in augmented block design.All fibre traits showed significant differences among genotypes,indicating that there is genetic potential for improvement.Fibre strength and micronaire(MIC) showed high phenotypic and genotypic coefficients of variation.High heritability combined with high genetic advance as percentage of mean(GAM) was recorded for fibre length,strength,and micronaire.Fibre strength and fibre length were significantly correlated with each other,while both showed negative correlation with micronaire.Principal component analysis and Biplot analysis showed that uniformity index discriminated all the genotypes in higher level,while fibre length and strength were medium in discrimination power.Biplot revealed genotypes DB 16,EC959191,GSB 39,ARBB 20,5746U,EA 203,and EA 201 were genetically diverse.Hierarchal cluster analysis based on unweighted paired group method using arithmetic average(UPGMA) grouped the genotypes into four clusters,with each cluster consisting of 4,18,48,and 38 genotypes,respectively.Conclusion Among the genotypes,34 for fibre length(> 35 mm),18 for fibre strength(> 40.4 g·tex^(-1)) and 66 for micronaire(3.7-4.2,A grade) were identified as potential accessions based on their superiority.The superior fibre genotypes identified in this study are potential lines for the ELS cotton breeding program.
文摘Natural fibre reinforced polymer composite(NFRPC)materials are gaining popularity in the modern world due to their eco-friendliness,lightweight nature,life-cycle superiority,biodegradability,low cost,and noble mechanical properties.Due to the wide variety of materials available that have comparable attributes and satisfy the requirements of the product design specification,material selection has become a crucial component of design for engineers.This paper discusses the study’s findings in choosing the suitable thermoplastic matrices of Natural Fibre Composites for Cyclist Helmet utilising the DMAIC,and GRA approaches.The results are based on integrating two decision methods implemented utilising two distinct decision-making approaches:qualitative and quantitative.This study suggested thermoplastic polyethylene as a particularly ideal matrix in composite cyclist helmets during the selection process for the best thermoplastic matrices material using the 6σtechnique,with the decision based on the highest performance,the lightest weight,and the most environmentally friendly criteria.The DMAIC and GRA approach significantly influenced the material selection process by offering different tools for each phase.In the future study,selection technique may have been more exhaustive if more information from other factors had been added.
基金supported by the National 12th Five Year Plan of Science and Technology Support Project(2015 BAL02b02)National Spark Plan Project(2015 GA690045),Jiangsu Province“Six Talent Peaks”Team Project(XCL-CXTD−007).
文摘In order to examine the biaxial compression-compression properties of rubber fibre reinforced concrete(RFRC),an experimental study on RFRC under different lateral compressive stresses was carried out by considering different rubber replacement rates and polypropylene fibre contents.The failure modes and mechanical property parameters of different RFRC working conditions were obtained from the experiment to explore the effects of rubber replacement rate and polypropylene fibre content on the biaxial compression-compression properties of RFRC.The following conclusions were drawn.Under the influence of lateral compressive stress,the biaxial compression-compression failure mode gradually developed from a columnar pattern to a flaky pattern,suggesting that the incorporation of rubber and polypropylene fibres into the concrete resulted in a significant change in the development of cracks.For different rubber replacement rates and polypropylene fibre contents,the vertical compressive stress exhibited the same developing trend under the influence of lateral compressive stress.Specifically,the lateral compressive stress imposed the minimum effect on the vertical compressive stress when the rubber replacement rate and polypropylene fibre content were 20%and 0.4%,respectively,and imposed the maximum effect when the rubber replacement rate and polypropylene fibre content were 20%and 0%,respectively.With the increase of rubber replacement rate,the vertical peak stress was significantly reduced,which implies that an appropriate amount of polypropylene fibres can increase the vertical peak stress to a certain extent.Then,the biaxial compression-compression mechanism of RFRC was analysed from the microscopic level by using scanning electron microscope(SEM).Meanwhile,based on Kupfer’s biaxial compression-compression failure criterion and the octahedral stress space,a biaxial compression-compression failure criterion for RFRC was proposed,which was proven to have good applicability.The research results of this study provide important theoretical basis for the engineering application and development of RFRC.
基金The result was obtained through the financial support of the Ministry of Education Malaysia under Grant Number RACER/2019/FKM-CARE/F00408This paper’s publication also funded by UTeM Incentive Jurnal Q00049/JURNAL/2020/FKM.
文摘Naturalfibre as a reinforcing agent has been widely used in many industrial applications.Nevertheless,several factors need to be considered,such as the size and weight percentage of thefibre used in binding.Using fused deposition modelling(FDM),this factor was investigated by varying the size of naturalfibre as the responding variable with afixed weight percentage of kenaffibre.The process of modifying the naturalfibre in terms of size might increase the dispersion of kenaffibre in the polymer matrix and increase the adhesion bonding between thefibre and matrix of composites,subsequently improving the interfacial bonding between these two phases.In this paper,the effect offibre size was evaluated by performing the mechanical test,Scanning Electron Micrograph(SEM)to observe the morphology of the composites,and also by surface analysis.The surface roughness was visualised using a 3D profilometer and thefigure was illustrated as colour shading in the image.The composite withfibre size≤100μm displayed better tensile andflexural strength,compared to other sizes.In conclusion,by reducing the size of thefibre,the composites could develop high strength performance for industrial applications.
文摘The advancement and novel technologies in materials science have been steadily growing toward adopting ethical practices.To reduce the stress on the environment the producers integrate novel materials to extend traditional functionality.They develop modern fibers that are eco-friendly,light,resilient,mechanically flexible,and easy to process.Moreover,novel fabrics are acquiring unique properties such as sensory capabilities,electrical conductivity,and data transmission.Cloths with characteristics such as hydrophobic cotton,plant-based textiles,antimicrobial fabrics,and shape memory polymers show versatility in textile innovations.Overall,these textile innovations provide sustainable alternatives,which are commercially viable and suitable for large-scale production.
文摘Fibres from a variety of sources are a common constituent of pig feeds. They provide a means to utilise locallyproduced plant materials which are often a by-product of the food or drink industry. The value of a high fibre diet in terms of producing satiety has long been recognised. However the addition of fibre can reduce feed intake, which is clearly detrimental during stages of the production cycle when nutrient needs are high, for example in growing piglets and during lactation. More recently, fibre has been found to promote novel benefits to pig production systems,particularly given the reduction in antimicrobial use world-wide, concern for the welfare of animals fed a restricted diet and the need to ensure that such systems are more environmentally friendly. For example, inclusion of dietary fibre can alter the gut microbiota in ways that could reduce the need for antibiotics, while controlled addition of certain fibre types may reduce nitrogen losses into the environment and so reduce the environmental cost of pig production.Of particular potential value is the opportunity to use crude fibre concentrates as ’functional’ feed additives to improve young pig growth and welfare. Perhaps the greatest opportunity for the use of high fibre diets is to improve the reproductive efficiency of pigs. Increased dietary fibre before mating improves oocyte maturation, prenatal survival and litter size; providing a consumer-acceptable means of increasing the amount of saleable meat produced per sow. The mechanisms responsible for these beneficial effects remain to be elucidated. However, changes in plasma and follicular fluid concentrations of key hormones and metabolites, as well as effects of the hypothalamic satiety centre on gonadotrophin secretion and epigenetic effects are strong candidates.
基金Project supported by the National Natural Science Foundation of China (Grant No 60372061).
文摘The dynamical behaviour of the erbium-doped fibre single-ring laser with an optical delay feedback is discussed. Simulation shows that as the delay rate increases, the lasing light displays period-doubling which leads to chaos and via reverse period-doubling route returns from chaos to periodic. At a particular delay rate the intermittently chaotic route to chaos is also observed. The identical synchronization based on chaos in this ring laser is demonstrated by numerical simulation.
基金supported by the Program for New Century Excellent Talents in University(No.NCET-11-0489)the Key Program of the National Natural Science Foundation of China(No.31470119)
文摘Background: Exogenous melatonin could induce cashmere growth. However, induced growth of cashmere fleece by melatonin implants cannot be combined with the typical growth, resulting in earlier shedding followed by another cycle of cashmere growth. To address this issue, we examine the effects on the cashmere yield, fibre characteristics, and the growth and reproductive performance of cashmere goats of planned administration of melatonin. Methods: Eighteen half-sib, female goats were assigned to two treatments (n = 9) including a control and a treatment where melatonin (2 mg/kg BW) was implanted at the end of April and end of June. Cashmere growth and shedding were observed for approximately ] year following implantation. Fibre samples were collected monthly to determine cumulative cashmere length. Initiation and cessation dates for cashmere growth as well as the rate of cashmere growth were calculated. Cashmere yield, weight gain of dam, kidding date, litter size, and birth weight were also recorded. Results: Melatonin implantation increased cashmere yield by 34.5 % (control 553.7 g vs. melatonin 745.0 g; P〈 0.01), cashmere length by 21.3 % (control 95.2 mm vs. melatonin 115.4 mm; P 〈 0.01), and decreased fibre diameter by 4.4 % (control 14.6 pm vs. melatonin 14.0 IJm; P 〈 0.03). In melatonin-treated goats, the average initiation date was earlier than in control goats (May 18, 2013 vs. July 2, 20]3; P〈 0.01) but there was a similar cessation date (March 22, 2014 vs. March 27, 2014). Consequently, the duration of cashmere growth was longer in melatonin-treated goats than in control goats (307 vs.270 days; P 〈 0.01). The final BW, average daily gain, kidding date, litter size, and birth weight were not influenced by melatonin implantation. Conclusions: These data indicate that melatonin implantation (2 mg/kg BW) on two occasions (late April and June) increased cashmere yield by combining the induced growth of cashmere fleece with the typical growth and decreased the fibre diameter without changing dam growth rate or reproductive performance.
文摘Geotechnical stability is a major concern for the long-term safety and integrity of underground infrastructures such as tunnels, railway stations, mine shafts and hydraulic power chambers. An effective geotechnical monitoring system is able to provide adequate warning to underground personnel prior to any unexpected major geotechnical failure. This paper reviews the conventional geotechnical monitoring sensors and the emerging Fibre Optic Sensing(FOS) techniques, pointing out their unique features and major differences. Recent advances in various FOS based monitoring systems, including Brillouin time domain distributed optical sensors and fibre Bragg grating(FBG) sensors, are investigated through a critical review of the laboratory studies and field applications used for underground geotechnical monitoring. Particular emphasis is given to fibre packaging, temperature compensation, installation methods and instrumentation performance in the underground environment. A detailed discussion of the advantages and limitations of each FOS monitoring system is also presented in this paper.
基金supported by the China Postdoctoral Science Foundation (Grant No. 20090451417)the China Postdoctoral Science Special Foundation (Grant No. 201003693)+1 种基金the Fundamental Research Funds for the Central Universities of China (Grant No. ZYGX2009J053)the National Natural Science Foundation of China (Grant No. 60736038)
文摘Based on the rate equations describing the erbium-doped fluoride glass (ZBLAN) fibre lasers with different pumping configurations being taken into account, this paper presents theoretical calculations related to the dynamic population density and the operation performance of a high power mid-infrared all-fibre erbium-doped ZBLAN fibre laser. It shows that the ground-state absorption, excited-state absorption and energy-transfer-upconversion processes co-exist and produce a population balance, causing the laser to operate stably at a continuous wave state. A good agreement between the theoretical results and recent experimental measurement is obtained. Furthermore, the laser structure parameters including fibre length, reflectance of output fibre Bragg grating and pumping configurations are quantitatively optimised to achieve the best performance. The results show, as expected, that the slope efficiency of the fibre laser can be improved significantly through optimisation, which then provides an important guide for the design of high-performance mid-infrared erbium-doped ZBLAN fibre lasers.