The systemic effects of gastrointestinal(GI)microbiota in health and during chronic diseases is increasingly recognised.Dietary strategies to modulate the GI microbiota during chronic diseases have demonstrated promis...The systemic effects of gastrointestinal(GI)microbiota in health and during chronic diseases is increasingly recognised.Dietary strategies to modulate the GI microbiota during chronic diseases have demonstrated promise.While changes in dietary intake can rapidly change the GI microbiota,the impact of dietary changes during acute critical illness on the microbiota remain uncertain.Dietary fibre is metabolised by carbohydrate-active enzymes and,in health,can alter GI microbiota.The aim of this scoping review was to describe the effects of dietary fibre supplementation in health and disease states,specifically during critical illness.Randomised controlled trials and prospective cohort studies that include adults(>18 years age)and reported changes to GI microbiota as one of the study outcomes using non-culture methods,were identified.Studies show dietary fibres have an impact on faecal microbiota in health and disease.The fibre,inulin,has a marked and specific effect on increasing the abundance of faecal Bifidobacteria.Short chain fatty acids produced by Bifidobacteria have been shown to be beneficial in other patient populations.Very few trials have evaluated the effect of dietary fibre on the GI microbiota during critical illness.More research is necessary to establish optimal fibre type,doses,duration of intervention in critical illness.展开更多
Polypropylene(PP) fibres have primarily used to control shrinkage cracks or mitigate explosive spalling in concrete structures exposed to fire or subjected to impact/blast loads, with limited investigations on capacit...Polypropylene(PP) fibres have primarily used to control shrinkage cracks or mitigate explosive spalling in concrete structures exposed to fire or subjected to impact/blast loads, with limited investigations on capacity improvement. This study unveils the possibility of using PP micro-fibres to improve the impact behaviour of fibre-reinforced ultra-high-performance concrete(FRUHPC) columns. Results show that the addition of fibres significantly improves the impact behaviour of FRUHPC columns by shifting the failure mechanism from brittle shear to favourable flexural failure. The addition of steel or PP fibres affected the impact responses differently. Steel fibres considerably increased the peak impact force(up to 18%) while PP micro-fibres slightly increased the peak(3%-4%). FRUHPC significantly reduced the maximum midheight displacement by up to 30%(under 20°impact) and substantially improved the displacement recovery by up to 100%(under 20° impact). FRUHPC with steel fibres significantly improved the energy absorption while those with PP micro-fibres reduced the energy absorption, which is different from the effect of PP-macro fibre reported in the literature. The optimal fibre content for micro-PP fibres is 1% due to its minimal fibre usage and low peak and residual displacement. This study highlights the potential of FRUHPC as a promising material for impact-resistant structures by creating a more favourable flexural failure mechanism, enhancing ductility and toughness under impact loading, and advancing the understanding of the role of fibres in structural performance.展开更多
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
Polypropylene fibres and three sizes of steel fibres reinforced concrete are discussed. The total fibres content ranges from 0 4%-0 95% by volume of concrete. A four point bending test is adopted on the notched pris...Polypropylene fibres and three sizes of steel fibres reinforced concrete are discussed. The total fibres content ranges from 0 4%-0 95% by volume of concrete. A four point bending test is adopted on the notched prisms with the size of 100?mm×100?mm×500?mm to investigate the effect of hybrid fibres on crack arresting. The research results show that there is a positive synergy effect between large steel fibres and polypropylene fibres on the load bearing capacity in the small displacement range. But this synergy effect disappears in the large displacement range. The large and strong steel fibre is better than soft polypropylene fibre and small steel fibre in the aspect of energy absorption capacity in the large displacement range. The static usage limitation for the hybrid fibres concrete with “wide peak' or “multi peaks' load CMOD pattern should be carefully selected. The ultimate load bearing capacity and the crack width or CMOD at this load level should be jointly considered.展开更多
In order to predict the damage behaviours of 3D-printed continuous carbon fibre(CCF)reinforced composites,when additional short carbon fibre(SCF)composite components are employed for continuous printing or special fun...In order to predict the damage behaviours of 3D-printed continuous carbon fibre(CCF)reinforced composites,when additional short carbon fibre(SCF)composite components are employed for continuous printing or special functionality,a novel path-dependent progressive failure(PDPF)numerical approach is developed.First,a progressive failure model using Hashin failure criteria with continuum damage mechanics to account for the damage initiation and evaluation of 3D-printed CCF reinforced polyamide(PA)composites is developed,based on actual fibre placement trajectories with physical measurements of 3D-printed CCF/PA constituents.Meanwhile,an elastic-plastic model is employed to predict the plastic damage behaviours of SCF/PA parts.Then,the accuracy of the PDPF model was validated so as to study 3D-printed CCF/PA composites with either negative Poisson's ratio or high stiffness.The results demonstrate that the proposed PDPF model can achieve higher prediction accuracies in mechanical properties of these 3D-printed CCF/PA composites.Mechanism analyses show that the stress distribution is generally aggregated in the CCF areas along the fibre placement paths,and the shear damage and matrix tensile/compressive damage are the key damage modes.This study provides a new approach with valuable information for characterising complex 3D-printed continuous fibre-matrix composites with variable mechanical properties and multiple constituents.展开更多
The poor interfacial stability not only deteriorates fibre lithium-ion batteries(FLBs)performance but also impacts their scalable applications.To efficiently address these challenges,Prof.Huisheng Peng team proposed a...The poor interfacial stability not only deteriorates fibre lithium-ion batteries(FLBs)performance but also impacts their scalable applications.To efficiently address these challenges,Prof.Huisheng Peng team proposed a generalized channel structures strategy with optimized in situ polymerization technology in their recent study.The resultant FLBs can be woven into different-sized powering textiles,providing a high energy density output of 128 Wh kg^(-1) and simultaneously demonstrating good durability even under harsh conditions.Such a promising strategy expands the horizon in developing FLB with particular polymer gel electrolytes,and significantly ever-deepening understanding of the scaled wearable energy textile system toward a sustainable future.展开更多
Coir fibre has generated much interest as an eco-friendly,sustainable fibre with low density.This review findings show that coir fibres are abundant,with an average global annual production of 1019.7×103 tonnes,w...Coir fibre has generated much interest as an eco-friendly,sustainable fibre with low density.This review findings show that coir fibres are abundant,with an average global annual production of 1019.7×103 tonnes,with about 63%of this volume produced from India.Extraction of coir has been carried out through water retting.However,the retting period has been limited to 4–10 months.The lignin content of coir is more than 60%higher than that of other natural fibres;hence,coir could double as a source of lignin for other applications.The diameter of coir fibres varies from 0.006 mm(Vietnam)to 0.577 mm(Thailand),and their tensile strength ranges from 68.4 MPa(Tanzania)to 343 MPa(Vietnam).Coir fibres from Vietnam and India exhibit the highest elongation at break(63.8%)and the highest Young’s modulus(6 GPa),respectively.More than 50%of the researchers within the scope of the reviewed studies employed the hand layup(HLU)manufacturing method with an epoxy resin matrix.Fibre volume fractions used range between 10%–65%.An outstanding tensile strength of 62.92 MPa at 49%fibre volume fraction was recorded for coir composites where the fibres were unidirectionally oriented and stacked in three layers,manufactured using epoxy resin and the HLU technique.Only a few works have been done using Vacuum-assisted resin transfer moulding(VARTM).The curing of composites was mostly carried out at an unspecified temperature and duration.A defined fibre volume fraction with a defined mixing and mixing time of the matrix is imperative.The degree of uniform dispersity of the fibres in the matrix is lacking.The creep behaviour of coir composites,coating and wider treatment parameters need to be explored for advanced applications.Recent findings on the applications of coir composites are equally highlighted.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
The disposal of discarded E-cigarette butts(E-CBs) presents significant environmental challenges due to their detrimental impacts on ecosystems. To find an environmentally sustainable method for managing this waste, t...The disposal of discarded E-cigarette butts(E-CBs) presents significant environmental challenges due to their detrimental impacts on ecosystems. To find an environmentally sustainable method for managing this waste, the potential for recycling E-CBs in asphalt pavements was investigated in this study. By focusing on the two primary components of E-CBs, namely cellulose fibre and polylactic acid(PLA), this research introduced a novel approach for recycling E-CBs in stone mastic asphalt(SMA) as a fibre additive in engineered pellet form. The prepared fibre pellets were directly added to aggregates to produce the SMA mixture. The resulting mixtures underwent a comprehensive evaluation through a series of standardized laboratory tests, including assessments of volumetric properties, indirect tensile strength(ITS), stiffness modulus, moisture susceptibility, and rutting resistance. The results were compared with SMA mixtures containing conventional cellulose fibres. Additionally, to examine the potential influence of PLA, a third mixture was prepared, incorporating both cellulose fibre and PLA. The findings indicate that the SMA using pelletized fibre can satisfy the technical specifications regarding the tests performed in this study, showing higher ITS and rutting resistance compared to the reference mixture. Moreover, the incorporation of PLA plastic reduced air void content and improved tensile strength, stiffness, and rutting resistance. This study highlights the potential for recycling E-CBs in asphalt mixtures, offering technical support for further development of sustainable recycling methods for this waste.展开更多
Coal chemical bases in Northwest China are suffering from geographical water scarcity and a large amount of highly saline wastewater that needs to be treated during the production process, resulting in water and energ...Coal chemical bases in Northwest China are suffering from geographical water scarcity and a large amount of highly saline wastewater that needs to be treated during the production process, resulting in water and energy consumption becoming a key issue in the process of confined zero discharge. Membrane distillation is a thermally driven water treatment technology that can achieve higher water production efficiency and lower energy consumption by using hollow fibre membrane distillation in combination with a vacuum permeation side. In this study, CFD simulation calculations and response surface method analysis of hollow fibre membrane modules were carried out to further reveal the effects of different process operating parameters on water yield and the interactions between the operating parameters. It was found that the influence of the parameters on the membrane flux was as follows: feed inlet temperature > vacuum pressure ≈ feed inlet flow rate > feed inlet sanility, and the optimal operating parameters were predicted to be vacuum pressure of 38.88 kPa, feed solution temperature of 353.15 K, feed solution concentration of 4.13%, and inlet velocity of 0.60 m/s, which achieve membrane flux of 38.90 kg∙m−2∙h−1 according to the response surface method. This study provides more in-depth theoretical guidance for the application of hollow fibre vacuum membrane distillation technology in the treatment of coal chemical high salt wastewater.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
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
This paper presents the development process relating to the conceptual design of glass/renewable natural fibrereinforced polymer hybrid composite motorcycle side cover.Motorcycle side cover is a component frequently m...This paper presents the development process relating to the conceptual design of glass/renewable natural fibrereinforced polymer hybrid composite motorcycle side cover.Motorcycle side cover is a component frequently made from plastic or steel that functions on covering the motorcycle parts,components and systems such as frame,battery,electrical systems and mechanical systems.Function Analysis Systems Techniques(FAST)is used to identify the functions of motorcycle side cover.The right-side cover of motorcycle model SYM E-Bonus 110 has been physically studied to identify the competitive benchmarking criteria.The functions and competitive benchmarking criteria are then compiled and integrated with the environmental requirements to identify the Product Design Specifications(PDS).The coir fibre has been selected from six identified dominant renewable natural fibre used for automotive component through integration of Ranking Method and Quality Based Selection(QBS).Then the polypropylene matrix is selected after shortlisting the existing thermoplastic that is used with coir fibre and has high suitability for injection moulding manufacturing.The polypropylene matrix is then evaluated using Weighted Evaluation Matrix(WEM)by comparing to benchmark material which is Acrylonitrile Butadiene Styrene(ABS).After that,the conceptual design development of glass/renewable coir fibre-reinforced polypropylene motorcycle side cover is carried out using an integrated Theory of Inventive Problem Solving(TRIZ)and Morphological Chart,followed by final conceptual design selection using integration of Pugh Scoring Method and QBS.The conceptual design development intended on improving the biodegradability to reduce pollution to the environment.However,the usage of glass/coir fibre-reinforced polypropylene hybrid composite may increase the weight due to higher density.Four innovative design concepts have been developed and the selected final concept design has the most minimum number of ribs and minimum thickness with the same ratio of glass fibre and natural fibre composition.展开更多
Toddy palm fruit have an apparent density below 0.8 g/cm³and offer an interesting lightweight construction potential in polylactide(PLA)composites reinforced with 37 mass-%fibres.Single fibre bundles show similar...Toddy palm fruit have an apparent density below 0.8 g/cm³and offer an interesting lightweight construction potential in polylactide(PLA)composites reinforced with 37 mass-%fibres.Single fibre bundles show similar mechanical properties compared with coir:tensile strength of 240 MPa,Young´s modulus of 3.8 GPa and an elongation at break of 31%.However,density and diameter(~50μm)of fruit fibre bundles are significantly lower.The compression moulded composites have a density of 0.9 g/cm³and achieved an unnotched Charpy impact strength of 12 kJ/m^(2),a tensile strength of 25 MPa,Young’s modulus of 1.9 GPa and an elongation at break of 9%.Due to the high porosity of the composites and the different stress-strain behaviour of fibre and matrix the fibre-reinforcement potential could not be fully used.Maximum stress of the composite was reached at the elongation at break of the PLA-matrix(~2%)while the fibre achieved its maximum stress at an elongation of~31%.After reaching the maximum stress of the composite,the fibres were pulled out from the matrix with low energy absorption,resulting in a decrease in stress and a limited reinforcement potential.Additionally,the study investigates whether an insect attack by the Asian fruit fly on the mesocarp has a significant influence on the mechanical fibre characteristics.The results have shown that only the rough surface of the fibre bundles is smoothed by insect infestation.The mechanical properties were not significantly affected.For this reason insect-infested fruits of the toddy palm,which are no longer suitable for food production,can be used for the production of sustainable composite materials.展开更多
The yttrium as a sintering aid was introduced into polycarbosilane(PCS) to prepare yttrium-containing PCS(PYCS).Two types of yttrium-containing SiC fibres,the SiC(OY) fibres and the SiC(Y) fibres,were fabricat...The yttrium as a sintering aid was introduced into polycarbosilane(PCS) to prepare yttrium-containing PCS(PYCS).Two types of yttrium-containing SiC fibres,the SiC(OY) fibres and the SiC(Y) fibres,were fabricated with PYCS.The structural evolution and the associated properties on changing from SiC(OY) to SiC(Y) fibres during the sintering process were studied.The chemical composition of the SiC(OY) fibres is SiC1.53O0.22Y0.005 with an amorphous structure.The composition of SiC(Y) fibres is SiC1.23O0.05Y0.005.The fibres are composed of a large number of β-SiC crystallites with a size of 50 nm and a small amount of α-SiC crystalline.The tensile strength and fracture toughness of the SiC(OY) fibres are 2.25 GPa and 2.37 MPa·m1/2,respectively,and 1.61 GPa,1.91 MPa·m1/2,respectively for SiC(Y) fibres.The SiC(Y) fibres have a higher thermal stability than the SiC(OY) fibres.展开更多
The creep performance of basalt fibre(BF)reinforced in asphalt mortar under uniaxial compressive loadings is investigated. The samples of basalt fibre asphalt mortar(BFAM) with different BF mass fractions(0. 1%,0...The creep performance of basalt fibre(BF)reinforced in asphalt mortar under uniaxial compressive loadings is investigated. The samples of basalt fibre asphalt mortar(BFAM) with different BF mass fractions(0. 1%,0. 2%, and 0. 5%) and without BF in asphalt mixture are prepared, and then submitted for the compressive strength test and corresponding creep test at a high in-service temperature.Besides, numerical simulations in finite element ABAQUS software were conducted to model the compressive creep test of mortar materials, where the internal structure of the fibre mortar was assumed to be a two-component composite material model such as fibre and mortar matrix. Finally, the influence factors of rheological behaviors of BFAM are further analyzed. Results indicate that compared to the control sample, the compressive strength of BFAM samples has a significant increase, and the creep and residual deformation are decreased. However, it also shows that the excessive fibre, i.e. with the BF content of 0. 5%, is unfavorable to the high-temperature stability of the mortar. Based on the analysis results, the prediction equations of parameters of the Burgers constitutive model for BFAM are proposed by considering the fibre factors.展开更多
The reflected optical caustics method is applied to study dynamic fracture problems in hardened cement paste. First both the unreinforced cement paste and the glass fibres reinforced cement paste specimens were fabric...The reflected optical caustics method is applied to study dynamic fracture problems in hardened cement paste. First both the unreinforced cement paste and the glass fibres reinforced cement paste specimens were fabricated and the reflective coating on the surface of the specimen was prepared. Secondly the crack path and the shadow spot patterns during the crack propagation process for the two specimens were recorded by using a multi-spark high speed camera.Thirdly some dynamic parameters of two cement paste specimens including crack onset time the dynamic stress intensity factor and crack growth velocity were determined and analyzed comparatively.This indicates that the glass fibres can improve the fracture resistance and delay fracture time.These results will play an important role in evaluating the dynamic fracture properties of cement paste.展开更多
The effects of fibre/matrix bonding, fabric density, fibre volume fraction and bundle size on microstructure, mechanical properties and failure mechanisms in carbon fibre reinforced composites (plastic and carbon mat...The effects of fibre/matrix bonding, fabric density, fibre volume fraction and bundle size on microstructure, mechanical properties and failure mechanisms in carbon fibre reinforced composites (plastic and carbon matrix) have been investigated. The microstructure of unloaded and cracked samples was studied by optical microscopy and scanning electron microscopy (SEM), respectively whereas the mechanical behaviour was examined by 3- point bending experiments. Exclusively one type of experimental resole type phenolic resin was applied. A strong fibre/matrix bonding, which is needed for high strength of carbon fibre reinforced plastic (CFRP) materials leads to severe composite damages during the pyrolysis resulting in low strength, brittle failure and a very low utilisation of the fibres strain to failure in C/C composites. Inherent fabric parameters such as an increasing fabric density or bundle size or a reduced fibre volume fraction introduce inhomogenities to the CFRP's microstructure. Results are lower strength and stiffness whereas the strain to failure increases or remains unchanged. Toughness is almost not affected. In C/C composites inhomogenities due to a reduced bundle size reduce strain to failure, strength, stiffness and toughness. Vice versa a declining fibre volume fraction leads to exactly the opposite behaviour. Increasing the fabric density (weight per unit area) causes similar effects as in CFRPs.展开更多
In this paper,the temperature dependence of birefringence in polarization maintaining photonic crystal fibres(PMPCFs) is investigated theoretically and experimentally.Utilizing the structural parameters of the PM-PC...In this paper,the temperature dependence of birefringence in polarization maintaining photonic crystal fibres(PMPCFs) is investigated theoretically and experimentally.Utilizing the structural parameters of the PM-PCF samples in the experiment,two effects leading to the birefringence variation under different temperatures are analysed,which are the thermal expansion of silica material and the refractive index variation due to the temperature variation.The actual birefringence variation of the PM-PCF is the combination of the two effects,which is in the order of 10-9 K-1 for both fibre samples.Calculation results also show that the influence of refractive index variation is the dominant contribution,which determines the tendency of the fibre birefringence variation with varying temperature.Then,the birefringence beat lengths of the two fibre samples are measured under the temperature,which varies from -40℃ to 80℃.A traditional PANDA-type polarization maintaining fibre(PMF) is also measured in the same way for comparison.The experimental results indicate that the birefringence variation of the PM-PCF due to temperature variation is far smaller than that of the traditional PMF,which agrees with the theoretical analysis.The ultra-low temperature dependence of the birefringence in the PM-PCF has great potential applications in temperature-insensitive fibre interferometers,fibre sensors,and fibre gyroscopes.展开更多
Polylactic acid(PLA)bioplastic is a common material used in Fused Deposition Modeling(FDM)3D printing.It is biodegradable and environmentally friendly biopolymer which made out of corn.However,it exhibits weak mechan...Polylactic acid(PLA)bioplastic is a common material used in Fused Deposition Modeling(FDM)3D printing.It is biodegradable and environmentally friendly biopolymer which made out of corn.However,it exhibits weak mechanical properties which reduced its usability as a functional prototype in a real-world application.In the present study,two PLA composites are created through coextruded with 3K carbon fibres and twisted Kevlar string(as core fibre)to form a fibre reinforced parts(FRP).The mechanical strength of printed parts was examined using ASTM D638 standard with a strain rate of 1 mm/min.It has been demonstrated that the FRPs coextruded with 3K carbon fibres had achieved significant improvement in Young’s modulus(+180.6%,9.205 GPa),ultimate tensile strength(+175.3%,103 MPa)and maximum tensile strain(+21.6%,1.833%).Although the Young’s modulus of Kevlar FRP was found to be similar to as compared to unreinforced PLA(~3.29 GPa),it has gained significant increment in terms of maximum tensile strain(+179.7%,104.64 MPa),and maximum tensile strain(+257%,5.384%).Thus,this study revealed two unique composite materials,in which the 3K carbon FRP can offer stiff and high strength structure while Kevlar FRP offers similar strength but at a higher elasticity.展开更多
文摘The systemic effects of gastrointestinal(GI)microbiota in health and during chronic diseases is increasingly recognised.Dietary strategies to modulate the GI microbiota during chronic diseases have demonstrated promise.While changes in dietary intake can rapidly change the GI microbiota,the impact of dietary changes during acute critical illness on the microbiota remain uncertain.Dietary fibre is metabolised by carbohydrate-active enzymes and,in health,can alter GI microbiota.The aim of this scoping review was to describe the effects of dietary fibre supplementation in health and disease states,specifically during critical illness.Randomised controlled trials and prospective cohort studies that include adults(>18 years age)and reported changes to GI microbiota as one of the study outcomes using non-culture methods,were identified.Studies show dietary fibres have an impact on faecal microbiota in health and disease.The fibre,inulin,has a marked and specific effect on increasing the abundance of faecal Bifidobacteria.Short chain fatty acids produced by Bifidobacteria have been shown to be beneficial in other patient populations.Very few trials have evaluated the effect of dietary fibre on the GI microbiota during critical illness.More research is necessary to establish optimal fibre type,doses,duration of intervention in critical illness.
基金the financial support from Australian Research Council(ARC)(Grant No.DP220100307).
文摘Polypropylene(PP) fibres have primarily used to control shrinkage cracks or mitigate explosive spalling in concrete structures exposed to fire or subjected to impact/blast loads, with limited investigations on capacity improvement. This study unveils the possibility of using PP micro-fibres to improve the impact behaviour of fibre-reinforced ultra-high-performance concrete(FRUHPC) columns. Results show that the addition of fibres significantly improves the impact behaviour of FRUHPC columns by shifting the failure mechanism from brittle shear to favourable flexural failure. The addition of steel or PP fibres affected the impact responses differently. Steel fibres considerably increased the peak impact force(up to 18%) while PP micro-fibres slightly increased the peak(3%-4%). FRUHPC significantly reduced the maximum midheight displacement by up to 30%(under 20°impact) and substantially improved the displacement recovery by up to 100%(under 20° impact). FRUHPC with steel fibres significantly improved the energy absorption while those with PP micro-fibres reduced the energy absorption, which is different from the effect of PP-macro fibre reported in the literature. The optimal fibre content for micro-PP fibres is 1% due to its minimal fibre usage and low peak and residual displacement. This study highlights the potential of FRUHPC as a promising material for impact-resistant structures by creating a more favourable flexural failure mechanism, enhancing ductility and toughness under impact loading, and advancing the understanding of the role of fibres in structural performance.
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.
文摘Polypropylene fibres and three sizes of steel fibres reinforced concrete are discussed. The total fibres content ranges from 0 4%-0 95% by volume of concrete. A four point bending test is adopted on the notched prisms with the size of 100?mm×100?mm×500?mm to investigate the effect of hybrid fibres on crack arresting. The research results show that there is a positive synergy effect between large steel fibres and polypropylene fibres on the load bearing capacity in the small displacement range. But this synergy effect disappears in the large displacement range. The large and strong steel fibre is better than soft polypropylene fibre and small steel fibre in the aspect of energy absorption capacity in the large displacement range. The static usage limitation for the hybrid fibres concrete with “wide peak' or “multi peaks' load CMOD pattern should be carefully selected. The ultimate load bearing capacity and the crack width or CMOD at this load level should be jointly considered.
基金Supported by National Natural Science Foundation of China (Grant No.12302177)Guangdong Provincial Basic and Applied Basic Research Foundation of China (Grant No.2024A1515010203)+1 种基金Shenzhen Science and Technology Program of China (Grant No.JCYJ20230807093602005)Shenzhen Key Laboratory of Intelligent Manufacturing for Continuous Carbon Fibre Reinforced Composites of China (Grant No.ZDSYS20220527171404011)。
文摘In order to predict the damage behaviours of 3D-printed continuous carbon fibre(CCF)reinforced composites,when additional short carbon fibre(SCF)composite components are employed for continuous printing or special functionality,a novel path-dependent progressive failure(PDPF)numerical approach is developed.First,a progressive failure model using Hashin failure criteria with continuum damage mechanics to account for the damage initiation and evaluation of 3D-printed CCF reinforced polyamide(PA)composites is developed,based on actual fibre placement trajectories with physical measurements of 3D-printed CCF/PA constituents.Meanwhile,an elastic-plastic model is employed to predict the plastic damage behaviours of SCF/PA parts.Then,the accuracy of the PDPF model was validated so as to study 3D-printed CCF/PA composites with either negative Poisson's ratio or high stiffness.The results demonstrate that the proposed PDPF model can achieve higher prediction accuracies in mechanical properties of these 3D-printed CCF/PA composites.Mechanism analyses show that the stress distribution is generally aggregated in the CCF areas along the fibre placement paths,and the shear damage and matrix tensile/compressive damage are the key damage modes.This study provides a new approach with valuable information for characterising complex 3D-printed continuous fibre-matrix composites with variable mechanical properties and multiple constituents.
基金the National Key R&D Program of China(2022YFA1203304)the Natural Science Foundation of Jiangsu Province(BK20220288)+1 种基金Suzhou Institute of Nano-Tech and Nano-Bionics,Chinese Academy of Sciences(Start-up grant E1552102)the China Postdoctoral Science Foundation(No.2023M732553).
文摘The poor interfacial stability not only deteriorates fibre lithium-ion batteries(FLBs)performance but also impacts their scalable applications.To efficiently address these challenges,Prof.Huisheng Peng team proposed a generalized channel structures strategy with optimized in situ polymerization technology in their recent study.The resultant FLBs can be woven into different-sized powering textiles,providing a high energy density output of 128 Wh kg^(-1) and simultaneously demonstrating good durability even under harsh conditions.Such a promising strategy expands the horizon in developing FLB with particular polymer gel electrolytes,and significantly ever-deepening understanding of the scaled wearable energy textile system toward a sustainable future.
文摘Coir fibre has generated much interest as an eco-friendly,sustainable fibre with low density.This review findings show that coir fibres are abundant,with an average global annual production of 1019.7×103 tonnes,with about 63%of this volume produced from India.Extraction of coir has been carried out through water retting.However,the retting period has been limited to 4–10 months.The lignin content of coir is more than 60%higher than that of other natural fibres;hence,coir could double as a source of lignin for other applications.The diameter of coir fibres varies from 0.006 mm(Vietnam)to 0.577 mm(Thailand),and their tensile strength ranges from 68.4 MPa(Tanzania)to 343 MPa(Vietnam).Coir fibres from Vietnam and India exhibit the highest elongation at break(63.8%)and the highest Young’s modulus(6 GPa),respectively.More than 50%of the researchers within the scope of the reviewed studies employed the hand layup(HLU)manufacturing method with an epoxy resin matrix.Fibre volume fractions used range between 10%–65%.An outstanding tensile strength of 62.92 MPa at 49%fibre volume fraction was recorded for coir composites where the fibres were unidirectionally oriented and stacked in three layers,manufactured using epoxy resin and the HLU technique.Only a few works have been done using Vacuum-assisted resin transfer moulding(VARTM).The curing of composites was mostly carried out at an unspecified temperature and duration.A defined fibre volume fraction with a defined mixing and mixing time of the matrix is imperative.The degree of uniform dispersity of the fibres in the matrix is lacking.The creep behaviour of coir composites,coating and wider treatment parameters need to be explored for advanced applications.Recent findings on the applications of coir composites are equally highlighted.
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.
基金the funding support from China Scholarship Council under the grant CSC No. 202106150028。
文摘The disposal of discarded E-cigarette butts(E-CBs) presents significant environmental challenges due to their detrimental impacts on ecosystems. To find an environmentally sustainable method for managing this waste, the potential for recycling E-CBs in asphalt pavements was investigated in this study. By focusing on the two primary components of E-CBs, namely cellulose fibre and polylactic acid(PLA), this research introduced a novel approach for recycling E-CBs in stone mastic asphalt(SMA) as a fibre additive in engineered pellet form. The prepared fibre pellets were directly added to aggregates to produce the SMA mixture. The resulting mixtures underwent a comprehensive evaluation through a series of standardized laboratory tests, including assessments of volumetric properties, indirect tensile strength(ITS), stiffness modulus, moisture susceptibility, and rutting resistance. The results were compared with SMA mixtures containing conventional cellulose fibres. Additionally, to examine the potential influence of PLA, a third mixture was prepared, incorporating both cellulose fibre and PLA. The findings indicate that the SMA using pelletized fibre can satisfy the technical specifications regarding the tests performed in this study, showing higher ITS and rutting resistance compared to the reference mixture. Moreover, the incorporation of PLA plastic reduced air void content and improved tensile strength, stiffness, and rutting resistance. This study highlights the potential for recycling E-CBs in asphalt mixtures, offering technical support for further development of sustainable recycling methods for this waste.
文摘Coal chemical bases in Northwest China are suffering from geographical water scarcity and a large amount of highly saline wastewater that needs to be treated during the production process, resulting in water and energy consumption becoming a key issue in the process of confined zero discharge. Membrane distillation is a thermally driven water treatment technology that can achieve higher water production efficiency and lower energy consumption by using hollow fibre membrane distillation in combination with a vacuum permeation side. In this study, CFD simulation calculations and response surface method analysis of hollow fibre membrane modules were carried out to further reveal the effects of different process operating parameters on water yield and the interactions between the operating parameters. It was found that the influence of the parameters on the membrane flux was as follows: feed inlet temperature > vacuum pressure ≈ feed inlet flow rate > feed inlet sanility, and the optimal operating parameters were predicted to be vacuum pressure of 38.88 kPa, feed solution temperature of 353.15 K, feed solution concentration of 4.13%, and inlet velocity of 0.60 m/s, which achieve membrane flux of 38.90 kg∙m−2∙h−1 according to the response surface method. This study provides more in-depth theoretical guidance for the application of hollow fibre vacuum membrane distillation technology in the treatment of coal chemical high salt wastewater.
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.
文摘This paper presents the development process relating to the conceptual design of glass/renewable natural fibrereinforced polymer hybrid composite motorcycle side cover.Motorcycle side cover is a component frequently made from plastic or steel that functions on covering the motorcycle parts,components and systems such as frame,battery,electrical systems and mechanical systems.Function Analysis Systems Techniques(FAST)is used to identify the functions of motorcycle side cover.The right-side cover of motorcycle model SYM E-Bonus 110 has been physically studied to identify the competitive benchmarking criteria.The functions and competitive benchmarking criteria are then compiled and integrated with the environmental requirements to identify the Product Design Specifications(PDS).The coir fibre has been selected from six identified dominant renewable natural fibre used for automotive component through integration of Ranking Method and Quality Based Selection(QBS).Then the polypropylene matrix is selected after shortlisting the existing thermoplastic that is used with coir fibre and has high suitability for injection moulding manufacturing.The polypropylene matrix is then evaluated using Weighted Evaluation Matrix(WEM)by comparing to benchmark material which is Acrylonitrile Butadiene Styrene(ABS).After that,the conceptual design development of glass/renewable coir fibre-reinforced polypropylene motorcycle side cover is carried out using an integrated Theory of Inventive Problem Solving(TRIZ)and Morphological Chart,followed by final conceptual design selection using integration of Pugh Scoring Method and QBS.The conceptual design development intended on improving the biodegradability to reduce pollution to the environment.However,the usage of glass/coir fibre-reinforced polypropylene hybrid composite may increase the weight due to higher density.Four innovative design concepts have been developed and the selected final concept design has the most minimum number of ribs and minimum thickness with the same ratio of glass fibre and natural fibre composition.
基金funded within the framework of the BMBF exchange project“Thai-German Agro-based Fibre Exchange Programme-Sustainable Development:From Plant to Product(Acronym:AgroFibre)”under the registration number 01DP15016.
文摘Toddy palm fruit have an apparent density below 0.8 g/cm³and offer an interesting lightweight construction potential in polylactide(PLA)composites reinforced with 37 mass-%fibres.Single fibre bundles show similar mechanical properties compared with coir:tensile strength of 240 MPa,Young´s modulus of 3.8 GPa and an elongation at break of 31%.However,density and diameter(~50μm)of fruit fibre bundles are significantly lower.The compression moulded composites have a density of 0.9 g/cm³and achieved an unnotched Charpy impact strength of 12 kJ/m^(2),a tensile strength of 25 MPa,Young’s modulus of 1.9 GPa and an elongation at break of 9%.Due to the high porosity of the composites and the different stress-strain behaviour of fibre and matrix the fibre-reinforcement potential could not be fully used.Maximum stress of the composite was reached at the elongation at break of the PLA-matrix(~2%)while the fibre achieved its maximum stress at an elongation of~31%.After reaching the maximum stress of the composite,the fibres were pulled out from the matrix with low energy absorption,resulting in a decrease in stress and a limited reinforcement potential.Additionally,the study investigates whether an insect attack by the Asian fruit fly on the mesocarp has a significant influence on the mechanical fibre characteristics.The results have shown that only the rough surface of the fibre bundles is smoothed by insect infestation.The mechanical properties were not significantly affected.For this reason insect-infested fruits of the toddy palm,which are no longer suitable for food production,can be used for the production of sustainable composite materials.
基金Projects (51175444,50532010) supported by the National Natural Science Foundation of ChinaProject (2011121002) supported by the Fundamental Research Funds for the Central Universities, ChinaProject (2009J1009) supported by Scientific and Technological Innovation Platform of Fujian Province,China
文摘The yttrium as a sintering aid was introduced into polycarbosilane(PCS) to prepare yttrium-containing PCS(PYCS).Two types of yttrium-containing SiC fibres,the SiC(OY) fibres and the SiC(Y) fibres,were fabricated with PYCS.The structural evolution and the associated properties on changing from SiC(OY) to SiC(Y) fibres during the sintering process were studied.The chemical composition of the SiC(OY) fibres is SiC1.53O0.22Y0.005 with an amorphous structure.The composition of SiC(Y) fibres is SiC1.23O0.05Y0.005.The fibres are composed of a large number of β-SiC crystallites with a size of 50 nm and a small amount of α-SiC crystalline.The tensile strength and fracture toughness of the SiC(OY) fibres are 2.25 GPa and 2.37 MPa·m1/2,respectively,and 1.61 GPa,1.91 MPa·m1/2,respectively for SiC(Y) fibres.The SiC(Y) fibres have a higher thermal stability than the SiC(OY) fibres.
基金The National Natural Science Foundation of China(No.51108082)
文摘The creep performance of basalt fibre(BF)reinforced in asphalt mortar under uniaxial compressive loadings is investigated. The samples of basalt fibre asphalt mortar(BFAM) with different BF mass fractions(0. 1%,0. 2%, and 0. 5%) and without BF in asphalt mixture are prepared, and then submitted for the compressive strength test and corresponding creep test at a high in-service temperature.Besides, numerical simulations in finite element ABAQUS software were conducted to model the compressive creep test of mortar materials, where the internal structure of the fibre mortar was assumed to be a two-component composite material model such as fibre and mortar matrix. Finally, the influence factors of rheological behaviors of BFAM are further analyzed. Results indicate that compared to the control sample, the compressive strength of BFAM samples has a significant increase, and the creep and residual deformation are decreased. However, it also shows that the excessive fibre, i.e. with the BF content of 0. 5%, is unfavorable to the high-temperature stability of the mortar. Based on the analysis results, the prediction equations of parameters of the Burgers constitutive model for BFAM are proposed by considering the fibre factors.
基金The Ph.D.Programs Foundation of Ministry of Education of China(No.20120023120020)the National Natural Science Foundation of China(No.51404273)
文摘The reflected optical caustics method is applied to study dynamic fracture problems in hardened cement paste. First both the unreinforced cement paste and the glass fibres reinforced cement paste specimens were fabricated and the reflective coating on the surface of the specimen was prepared. Secondly the crack path and the shadow spot patterns during the crack propagation process for the two specimens were recorded by using a multi-spark high speed camera.Thirdly some dynamic parameters of two cement paste specimens including crack onset time the dynamic stress intensity factor and crack growth velocity were determined and analyzed comparatively.This indicates that the glass fibres can improve the fracture resistance and delay fracture time.These results will play an important role in evaluating the dynamic fracture properties of cement paste.
文摘The effects of fibre/matrix bonding, fabric density, fibre volume fraction and bundle size on microstructure, mechanical properties and failure mechanisms in carbon fibre reinforced composites (plastic and carbon matrix) have been investigated. The microstructure of unloaded and cracked samples was studied by optical microscopy and scanning electron microscopy (SEM), respectively whereas the mechanical behaviour was examined by 3- point bending experiments. Exclusively one type of experimental resole type phenolic resin was applied. A strong fibre/matrix bonding, which is needed for high strength of carbon fibre reinforced plastic (CFRP) materials leads to severe composite damages during the pyrolysis resulting in low strength, brittle failure and a very low utilisation of the fibres strain to failure in C/C composites. Inherent fabric parameters such as an increasing fabric density or bundle size or a reduced fibre volume fraction introduce inhomogenities to the CFRP's microstructure. Results are lower strength and stiffness whereas the strain to failure increases or remains unchanged. Toughness is almost not affected. In C/C composites inhomogenities due to a reduced bundle size reduce strain to failure, strength, stiffness and toughness. Vice versa a declining fibre volume fraction leads to exactly the opposite behaviour. Increasing the fabric density (weight per unit area) causes similar effects as in CFRPs.
文摘In this paper,the temperature dependence of birefringence in polarization maintaining photonic crystal fibres(PMPCFs) is investigated theoretically and experimentally.Utilizing the structural parameters of the PM-PCF samples in the experiment,two effects leading to the birefringence variation under different temperatures are analysed,which are the thermal expansion of silica material and the refractive index variation due to the temperature variation.The actual birefringence variation of the PM-PCF is the combination of the two effects,which is in the order of 10-9 K-1 for both fibre samples.Calculation results also show that the influence of refractive index variation is the dominant contribution,which determines the tendency of the fibre birefringence variation with varying temperature.Then,the birefringence beat lengths of the two fibre samples are measured under the temperature,which varies from -40℃ to 80℃.A traditional PANDA-type polarization maintaining fibre(PMF) is also measured in the same way for comparison.The experimental results indicate that the birefringence variation of the PM-PCF due to temperature variation is far smaller than that of the traditional PMF,which agrees with the theoretical analysis.The ultra-low temperature dependence of the birefringence in the PM-PCF has great potential applications in temperature-insensitive fibre interferometers,fibre sensors,and fibre gyroscopes.
基金This project is funded by Universiti Tunku Abdul Rahman through the grant number IPSR/RMC/UTARRF/2018-C2/T02.
文摘Polylactic acid(PLA)bioplastic is a common material used in Fused Deposition Modeling(FDM)3D printing.It is biodegradable and environmentally friendly biopolymer which made out of corn.However,it exhibits weak mechanical properties which reduced its usability as a functional prototype in a real-world application.In the present study,two PLA composites are created through coextruded with 3K carbon fibres and twisted Kevlar string(as core fibre)to form a fibre reinforced parts(FRP).The mechanical strength of printed parts was examined using ASTM D638 standard with a strain rate of 1 mm/min.It has been demonstrated that the FRPs coextruded with 3K carbon fibres had achieved significant improvement in Young’s modulus(+180.6%,9.205 GPa),ultimate tensile strength(+175.3%,103 MPa)and maximum tensile strain(+21.6%,1.833%).Although the Young’s modulus of Kevlar FRP was found to be similar to as compared to unreinforced PLA(~3.29 GPa),it has gained significant increment in terms of maximum tensile strain(+179.7%,104.64 MPa),and maximum tensile strain(+257%,5.384%).Thus,this study revealed two unique composite materials,in which the 3K carbon FRP can offer stiff and high strength structure while Kevlar FRP offers similar strength but at a higher elasticity.