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
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
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
The Merkel cell-neurite complex initiates the perception of touch and mediates Ap slowly adapting type I responses. Lichen planus is a chronic inflammatory autoimmune disease with T-cell-mediated inflammation, whereas...The Merkel cell-neurite complex initiates the perception of touch and mediates Ap slowly adapting type I responses. Lichen planus is a chronic inflammatory autoimmune disease with T-cell-mediated inflammation, whereas hyperkeratosis is characterized with or without epithelial dysplasia in the oral mucosa. To determine the effects of lichen planus and hyperkeratosis on the Merkel cell-neurite complex, healthy oral mucosal epithelium and lesional oral mucosal epithelium of lichen planus and hyperkeratosis patients were stained by immunohistochemistry (the avidin-biotin-peroxidase complex and double immunofluorescence methods)using pan cytokeratin, cytokeratin 20 (K20, a Merkel cell marker), and neurofilament 200 (NF200, a myelinated Aβ- and Aδ-nerve fibre marker) antibodies. N F200-immunoreactive (ir) nerve fibres in healthy tissues and in the lesional oral mucosa epithelium of lichen planus and hyperkeratosis were counted and statistically analysed. In the healthy oral mucosa, K20-positive Merkel cells with and without close association to the intraepithelial NF200-ir nerve fibres were detected. In the lesional oral mucosa of lichen planus and hyperkeratosis patients, extremely rare NF200-ir nerve fibres were detected only in the lamina propria. Compared with healthy tissues, lichen planus and hyperkeratosis tissues had significantly decreased numbers of NF200-ir nerve fibres in the oral mucosal epithelium. Lichen planus and hyperkeratosis were associated with the absence of Aβ-nerve endings in the oral mucosal epithelium. Thus, we conclude that mechanosensation mediated by the Merkel cell-neurite complex in the oral mucosal epithelium is impaired in lichen planus and hvperkeratosis.展开更多
The orientation and concentration distributions of fibres in laminar and turbulent channel flows are investigated numerically. The obtained results are in good agreement with the experimental data. In the laminar flow...The orientation and concentration distributions of fibres in laminar and turbulent channel flows are investigated numerically. The obtained results are in good agreement with the experimental data. In the laminar flow regime, more fibres orient to the flow direction as the Reynolds number increases. The shear rate of fluid around a fibre plays an important role in determining the orientation distribution of fibres, while the fibre density and the fibre aspect-ratio have marginal influence on the orientation distribution. In the turbulent regime, the orientation distribution of fibres becomes more homogeneous with the increase of Reynolds number, and the concentration profile is flatter than that in the laminar regime. The fluctuating intensity of fibre velocity in the downstream direction is larger than that in the lateral directions.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
Titanium metal matrix composites (TiMMCs) reinforced by continuous silicon carbide fibres are being developed for aerospace applications. TiMMCs manufactured by the consolidation of matrix-coated fibre (MCF) metho...Titanium metal matrix composites (TiMMCs) reinforced by continuous silicon carbide fibres are being developed for aerospace applications. TiMMCs manufactured by the consolidation of matrix-coated fibre (MCF) method offer optimum properties because of the resulting uniform fibre distribution, minimum fibre damage and fibre volume fraction control. In this paper, the consolidation of Ti-6Al-4V matrix-coated SiC fibres during vacuum hot pressing has been investigated. Experiments were carried out on multi-ply MCFs under vacuum hot pressing (VHP). In contrast to most of existing studies, the fibre, arrangement has been carefully controlled either in square or hexagonal arrays throughout the consolidated sample. This has enabled the dynamic consolidation behaviour of MCFs to be demonstrated by eliminating the fibre re-arrangement during the VHP process. The microstructural evolution of the matrix coating was reported and the deformation mechanisms involved were discussed.展开更多
In this paper, the generalized nonlinear Schrodinger equation (GNLSE) is solved by an adaptive split-step Fourier method (ASSFM). It is found that ASSFM must be used to solve GNLSE to ensure precision when the sol...In this paper, the generalized nonlinear Schrodinger equation (GNLSE) is solved by an adaptive split-step Fourier method (ASSFM). It is found that ASSFM must be used to solve GNLSE to ensure precision when the soliton selffrequency shift is remarkable and the photonic crystal fibre (PCF) parameters vary with the frequency considerably. The precision of numerical simulation by using ASSFM is higher than that by using split-step Fourier method in the process of laser pulse propagation in PCFs due to the fact that the variation of fibre parameters with the peak frequency in the pulse spectrum can be taken into account fully.展开更多
To study the adsorption properties of organic functional groups in plant fibres and identify a highly efficient and affordable adsorbent for radioactive wastewater treatment,natural bamboo fibre(NBF)samples were prepa...To study the adsorption properties of organic functional groups in plant fibres and identify a highly efficient and affordable adsorbent for radioactive wastewater treatment,natural bamboo fibre(NBF)samples were prepared,and the adsorption properties of Eu(Ⅲ)on NBFs were studied under given experimental conditions.The effects of the pH,solid-to-liquid ratio,background ions,humic acid,contact time,and temperature on the adsorption behaviour of Eu(Ⅲ)on NBFs were investigated.Adsorption was greatly influenced by pH,and the adsorption curves presented two inflection points at pH≈7 and pH≈11.Moreover,while the ionic strength presented a negative effect at pH<7,the high ionic strength favoured adsorption at pH>7.During adsorption on NBFs,the–OH,C–H,O–H,C–O,and C=O were the main adsorption groups.Hydrolysis occurring on the NBF surface caused the adsorption process to become increasingly difficult at pH>7.The maximum adsorption capacity of NBFs was 147.6 mg/g at 308 K,and the adsorption could be described using the pseudo-second-order kinetic model.The adsorption of Eu(Ⅲ)on NBFs was a spontaneous and endothermic process according to the thermodynamic parameters of the process,and the adsorption thermodynamics could be well described using the Freundlich adsorption model.Therefore,NBFs were determined to be an efficient,inexpensive,and easily disposable sewage treatment material.展开更多
The flexible structure of photonic crystal fibre not only offers novel optical properties but also brings some difficulties in keeping the fibre structure in the fabrication process which inevitably cause the optical ...The flexible structure of photonic crystal fibre not only offers novel optical properties but also brings some difficulties in keeping the fibre structure in the fabrication process which inevitably cause the optical properties of the resulting fibre to deviate from the designed properties. Therefore, a method of evaluating the optical properties of the actual fibre is necessary for the purpose of application. Up to now, the methods employed to measure the properties of the actual photonic crystal fibre often require long fibre samples or complex expensive equipments. To our knowledge, there are few studies of modeling an actual photonic crystal fibre and evaluating its properties rapidly. In this paper, a novel method, based on the combination model of digital image processing and the finite element method, is proposed to rapidly model the optical properties of the actual photonic crystal fibre. Two kinds of photonic crystal fibres made by Crystal Fiber A/S are modeled. It is confirmed from numerical results that the proposed method is simple, rapid and accurate for evaluating the optical properties of the actual photonic crystal fibre without requiring complex equipment.展开更多
This paper theoretically studies the double-pumped fibre-optical parametric amplifiers (FOPAs) in photonic crystal fibres. Two distinct working regimes of FOPAs are researched, which depend on the dispersion at the ...This paper theoretically studies the double-pumped fibre-optical parametric amplifiers (FOPAs) in photonic crystal fibres. Two distinct working regimes of FOPAs are researched, which depend on the dispersion at the central wavelength of the two pumps. Extremely broad tuning range can be obtained when the central pump wavelength is in the normal dispersion regime and is insensitive to the wavelength separation between the two pumps, while the tuning range is narrow in the anomalous dispersion regime and can be significantly enhanced by increasing the wavelength separation. Impacts of higher-order dispersions and temporal walk-off on the gain spectra are also discussed.展开更多
Beta-nerve growth factor(β-NGF)is known to be a major leading cause of neuronal plasticity.To identify the possible action mechanisms ofβ-NGF gene therapy for sciatic nerve recovery,experimental dogs were randomly d...Beta-nerve growth factor(β-NGF)is known to be a major leading cause of neuronal plasticity.To identify the possible action mechanisms ofβ-NGF gene therapy for sciatic nerve recovery,experimental dogs were randomly divided into control,pyridoxine,and pyridoxine+β-NGF groups.We observed chronological changes of morphology in the dorsal root ganglia in response to pyridoxine toxicity based on cresyl violet staining.The number of large neurons positive for cresyl violet was dramatically decreased after pyridoxine intoxication for 7 days in the dorsal root ganglia and the neuron number was gradually increased after pyridoxine withdrawal.In addition,we also investigated the effects ofβ-NGF gene therapy on neuronal plasticity in pyridoxine-induced neuropathic dogs.To accomplish this,tyrosine kinase receptor A(TrkA),βIII-tubulin and doublecortin(DCX)immunohistochemical staining was performed at 3 days after the last pyridoxine treatment.TrkA-immunoreactive neurons were dramatically decreased in the pyridoxine group compared to the control group,but strong TrkA immunoreactivity was observed in the small-sized dorsal root ganglia in this group.TrkA immunoreactivity in the dorsal root ganglia was similar betweenβ-NGF and control groups.The numbers ofβⅢ-tubulin-and DCX-immunoreactive cells decreased significantly in the pyridoxine group compared to the control group.However,the reduction ofβⅢ-tubulin-and DCX-immunoreactive cells in the dorsal root ganglia in theβ-NGF group was significantly ameliorated than that in the pyridoxine group.These results indicate thatβ-NGF gene therapy is a powerful treatment of pyridoxine-induced neuropathic damage by increasing the TrkA and DCX levels in the dorsal root ganglia.The experimental protocol was approved by the Institutional Animal Care and Use Committee(IACUC)of Seoul National University,South Korea(approval No.SNU-060623-1,SNU-091009-1)on June 23,2006 and October 9,2009,respectively.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
The aim of this study is to investigate the effect of chemical extraction method on the properties of doum palm fibres. The method of extraction which is carried out is a soda treatment. First, an investigation of the...The aim of this study is to investigate the effect of chemical extraction method on the properties of doum palm fibres. The method of extraction which is carried out is a soda treatment. First, an investigation of the extraction processes was undertaken. Secondly, the physical properties (surface morphology, density, linear density and diameter), the mechanical properties (tenacity, strain) and chemical properties (FT-IR spectra) of doum palm fibres were inspected. Finally, a comparison between properties of doum palm fibres and other vegetal ones has been included. Results indicates an influence of soda treatment on properties of Doum palm fibers. In fact, there is an improvement on fibers diameter and linear density while increasing soda concentration, temperature and treatment duration. Moreover, the studied fibers have a low density which does not exceed 1. The fibers tenacity achieved the maximum value of 20.86 cN/Tex when precessing in the following combination (0.75 N, 100°C and 180 mn). In the end, the FTIR spectra reveals a change in structure after this alkali treatment while increasing the cellulose amount exposed on the fiber surface and consequently the number of possible reaction sites (OH groups).展开更多
This paper focuses on the study of the physical, biochemical, structural, and thermal properties of plant fibres of <i>Rhecktophyllum camerunense</i> (RC), <i>Neuropeltis acuminatas</i> (NA) an...This paper focuses on the study of the physical, biochemical, structural, and thermal properties of plant fibres of <i>Rhecktophyllum camerunense</i> (RC), <i>Neuropeltis acuminatas</i> (NA) and <i>Ananas</i> <i>comosus</i> (AC) from the equatorial region of Cameroon. The traditional use of these fibres inspired researchers to investigated their properties. This study aims at improving the state of knowledge with a view to diversifying applications. The fibres are extracted by retting. Then, their apparent density was measured following the ASTM D792 standard and their water moisture absorption and moisture content were also evaluated. Their molecular structure was studied by ATR-FTIR spectroscopy. A quantitative analysis of the biochemical composition was performed according to the analytical technique for the pulp and paper industry (TAPPI). A TGA/DSC analysis was also performed. The results reveal that the AC, NA and RC fibres have densities of 1.26 ± 1.06, 0.846 ± 0.13 and 0.757 ± 0.08 g·cm<sup>-3</sup> respectively. They are also hydrophilic with a water absorption rate of 188.64 ± 11.94%, 276.16% ± 8.07% and 198.17% ± 20%. They have a moisture content of 12.21%, 10.36% and 9.37%. The studied fibres exhibit functional groups that are related to the presence of hemicellulose, pectin, lignin and cellulose. The cellulose crystallinity index was found to be 67.99%, 46.5% and 59.72% respectively. The fibres under study have the following chemical composition: an extractive content of 3.07%, 14.77% and 8.74%;a pectin content of 4.15%, 7.69% and 3.45%;a hemicellulose content of 4.90%, 15.33% and 7.42%;a cellulose content of 68.11%, 36.08% and 65.15%;a lignin content of 12.01%, 25.15% and 16.2%;and an ash content of 0.27%, 1.53% and 0.47% respectively. The thermal transitions observed on the thermograms correlate with the TAPPI chemical composition. It is observed that these fibres are thermally stable up to temperatures of 200°C, 220°C and 285°C. These results make it possible to envisage uses similar to those of sisal, hemp and flax fibres.展开更多
With the full-vector plane-wave method (FVPWM) and the full-vector beam propagation method (FVBPM), the dependences of the band-gap and mode characteristics on material index and cladding structure parameter in an...With the full-vector plane-wave method (FVPWM) and the full-vector beam propagation method (FVBPM), the dependences of the band-gap and mode characteristics on material index and cladding structure parameter in anti- resonance guiding photonic crystal fibres (ARGPCFs) are sufficiently analysed. An ARGPCF operating in the near- infrared wavelength is shown. The influences of the high index cylinders, glass interstitial apexes and silica structure on the characteristics of band-gaps and modes are deeply investigated. The equivalent planar waveguide theory is used for analysing such an ARGPCF filled by the isotropic materials, and the resonance and the anti-resonance characteristics r:~n h~ w~|] r^r~dlrtpd展开更多
The mechanical and damage properties of single fibres used in fibrous composite have gained tremendous importance in recent years. These properties are used in determination of effective properties of composites by mi...The mechanical and damage properties of single fibres used in fibrous composite have gained tremendous importance in recent years. These properties are used in determination of effective properties of composites by micromechanics. These are also used in the micromechanical damage modeling. Further, these properties are used as an indicator of the excellence of product by manufacturers. In the present study the axial tensile modulus, ultimate strength and failure strain of single fibres are determined for carbon and glass fibres. ASTM D3379-75 standard is followed and a number of fibers are tested for statistical analysis. The axial tensile moduli measured are 246.7 GPa and 93.3 GPa, respectively and strength are 3031.6 MPa and 2035.9 MPa, respectively for carbon and glass fibres. Further, the respective axial tensile failure strains are 0.0137 and 0.0224. The error in the measurement of axial modulus is below 8% while for axial tensile strength is below 1%.展开更多
Here,we report the mechanical and water sorption properties of a green composite based on Typha latifolia fibres.The composite was prepared either completely binder-less or bonded with 10%(w/w)of a bio-based resin whi...Here,we report the mechanical and water sorption properties of a green composite based on Typha latifolia fibres.The composite was prepared either completely binder-less or bonded with 10%(w/w)of a bio-based resin which was a mixture of an epoxidized linseed oil and a tall-oil based polyamide.The flexural modulus of elasticity,the flexural strength and the water absorption of hot pressed Typha panels were measured and the influence of pressing time and panel density on these properties was investigated.The cure kinetics of the biobased resin was analyzed by differential scanning calorimetry(DSC)in combination with the iso-conversional kinetic analysis method of Vyazovkin to derive the curing conditions required for achieving completely cured resin.For the binderless Typha panels the best technological properties were achieved for panels with high density.By adding 10%of the binder resin the flexural strength and especially the water absorption were improved significantly.展开更多
The growing environmental concerns have led to attention on bio-based composite materials, such as the natural fibres, recycled carbon fibres and bio-based resins. Herein, the bio-based epoxy composites were reinforce...The growing environmental concerns have led to attention on bio-based composite materials, such as the natural fibres, recycled carbon fibres and bio-based resins. Herein, the bio-based epoxy composites were reinforced with ramie fibre (RF) and recycled carbon fibre (rCF) via inter-layer hybridisation. The dynamic mechanical analysis, tensile, flexural and impact properties characterisation were conducted to analyse the mechanical behaviour of the specimens. Also, the morphology of fractured surface after mechanical tests was studied under a scanning electron microscope. When the volume ratio between RF and rCF was varied from 100/0 to 0/100, the flexural and tensile strength of composites was significantly increased, while the impact strength was reduced. Thus the maximum values of flexural strength (182 MPa) and tensile strength (165 MPa) were observed for rCF reinforced composite, whilst impact strength of 24 kJ/m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> was found for RF reinforced composite. Furthermore, the values of storage and loss modulus were increased with the rCF incorporation due to a greater degree of restriction with the addition of rCF into the matrix. The hybridisation was able to combine the specific properties of RF and rCF and optimise the mechanical performance of composites. Therefore, the alternative low-cost green composites are prepared which can replace synthetic materials for semi-structural applications.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.
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.
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.
文摘The Merkel cell-neurite complex initiates the perception of touch and mediates Ap slowly adapting type I responses. Lichen planus is a chronic inflammatory autoimmune disease with T-cell-mediated inflammation, whereas hyperkeratosis is characterized with or without epithelial dysplasia in the oral mucosa. To determine the effects of lichen planus and hyperkeratosis on the Merkel cell-neurite complex, healthy oral mucosal epithelium and lesional oral mucosal epithelium of lichen planus and hyperkeratosis patients were stained by immunohistochemistry (the avidin-biotin-peroxidase complex and double immunofluorescence methods)using pan cytokeratin, cytokeratin 20 (K20, a Merkel cell marker), and neurofilament 200 (NF200, a myelinated Aβ- and Aδ-nerve fibre marker) antibodies. N F200-immunoreactive (ir) nerve fibres in healthy tissues and in the lesional oral mucosa epithelium of lichen planus and hyperkeratosis were counted and statistically analysed. In the healthy oral mucosa, K20-positive Merkel cells with and without close association to the intraepithelial NF200-ir nerve fibres were detected. In the lesional oral mucosa of lichen planus and hyperkeratosis patients, extremely rare NF200-ir nerve fibres were detected only in the lamina propria. Compared with healthy tissues, lichen planus and hyperkeratosis tissues had significantly decreased numbers of NF200-ir nerve fibres in the oral mucosal epithelium. Lichen planus and hyperkeratosis were associated with the absence of Aβ-nerve endings in the oral mucosal epithelium. Thus, we conclude that mechanosensation mediated by the Merkel cell-neurite complex in the oral mucosal epithelium is impaired in lichen planus and hvperkeratosis.
基金Project supported by the National Natural Science Foundation (Grant No 10372090) and the Doctorate Program of Higher Education of China (Grant No 20030335001).
文摘The orientation and concentration distributions of fibres in laminar and turbulent channel flows are investigated numerically. The obtained results are in good agreement with the experimental data. In the laminar flow regime, more fibres orient to the flow direction as the Reynolds number increases. The shear rate of fluid around a fibre plays an important role in determining the orientation distribution of fibres, while the fibre density and the fibre aspect-ratio have marginal influence on the orientation distribution. In the turbulent regime, the orientation distribution of fibres becomes more homogeneous with the increase of Reynolds number, and the concentration profile is flatter than that in the laminar regime. The fluctuating intensity of fibre velocity in the downstream direction is larger than that in the lateral directions.
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.
文摘Titanium metal matrix composites (TiMMCs) reinforced by continuous silicon carbide fibres are being developed for aerospace applications. TiMMCs manufactured by the consolidation of matrix-coated fibre (MCF) method offer optimum properties because of the resulting uniform fibre distribution, minimum fibre damage and fibre volume fraction control. In this paper, the consolidation of Ti-6Al-4V matrix-coated SiC fibres during vacuum hot pressing has been investigated. Experiments were carried out on multi-ply MCFs under vacuum hot pressing (VHP). In contrast to most of existing studies, the fibre, arrangement has been carefully controlled either in square or hexagonal arrays throughout the consolidated sample. This has enabled the dynamic consolidation behaviour of MCFs to be demonstrated by eliminating the fibre re-arrangement during the VHP process. The microstructural evolution of the matrix coating was reported and the deformation mechanisms involved were discussed.
文摘In this paper, the generalized nonlinear Schrodinger equation (GNLSE) is solved by an adaptive split-step Fourier method (ASSFM). It is found that ASSFM must be used to solve GNLSE to ensure precision when the soliton selffrequency shift is remarkable and the photonic crystal fibre (PCF) parameters vary with the frequency considerably. The precision of numerical simulation by using ASSFM is higher than that by using split-step Fourier method in the process of laser pulse propagation in PCFs due to the fact that the variation of fibre parameters with the peak frequency in the pulse spectrum can be taken into account fully.
基金supported by the National Natural Science Foundation of China(No.21561001)the Natural Science Foundation of Jiangxi Province,China(No.20161BAB203100)
文摘To study the adsorption properties of organic functional groups in plant fibres and identify a highly efficient and affordable adsorbent for radioactive wastewater treatment,natural bamboo fibre(NBF)samples were prepared,and the adsorption properties of Eu(Ⅲ)on NBFs were studied under given experimental conditions.The effects of the pH,solid-to-liquid ratio,background ions,humic acid,contact time,and temperature on the adsorption behaviour of Eu(Ⅲ)on NBFs were investigated.Adsorption was greatly influenced by pH,and the adsorption curves presented two inflection points at pH≈7 and pH≈11.Moreover,while the ionic strength presented a negative effect at pH<7,the high ionic strength favoured adsorption at pH>7.During adsorption on NBFs,the–OH,C–H,O–H,C–O,and C=O were the main adsorption groups.Hydrolysis occurring on the NBF surface caused the adsorption process to become increasingly difficult at pH>7.The maximum adsorption capacity of NBFs was 147.6 mg/g at 308 K,and the adsorption could be described using the pseudo-second-order kinetic model.The adsorption of Eu(Ⅲ)on NBFs was a spontaneous and endothermic process according to the thermodynamic parameters of the process,and the adsorption thermodynamics could be well described using the Freundlich adsorption model.Therefore,NBFs were determined to be an efficient,inexpensive,and easily disposable sewage treatment material.
基金Project supported by the National Basic Research Program of China(Grant No.2010CB328206)the National Natural Science Foundation of China(Grant No.60977033)the Science and Technology Innovation Foundation for Excellent Doctors of Beijing Jiaotong University,China(Grant Nos.141055522 and 141060522)
文摘The flexible structure of photonic crystal fibre not only offers novel optical properties but also brings some difficulties in keeping the fibre structure in the fabrication process which inevitably cause the optical properties of the resulting fibre to deviate from the designed properties. Therefore, a method of evaluating the optical properties of the actual fibre is necessary for the purpose of application. Up to now, the methods employed to measure the properties of the actual photonic crystal fibre often require long fibre samples or complex expensive equipments. To our knowledge, there are few studies of modeling an actual photonic crystal fibre and evaluating its properties rapidly. In this paper, a novel method, based on the combination model of digital image processing and the finite element method, is proposed to rapidly model the optical properties of the actual photonic crystal fibre. Two kinds of photonic crystal fibres made by Crystal Fiber A/S are modeled. It is confirmed from numerical results that the proposed method is simple, rapid and accurate for evaluating the optical properties of the actual photonic crystal fibre without requiring complex equipment.
基金Project partially supported by the Shanghai Committee of Science and Technology, China (Grant Nos 05 SG 02 and 05 JC 14005)the National Natural Science Foundation of China (Grant Nos 60538010 and 10376009)
文摘This paper theoretically studies the double-pumped fibre-optical parametric amplifiers (FOPAs) in photonic crystal fibres. Two distinct working regimes of FOPAs are researched, which depend on the dispersion at the central wavelength of the two pumps. Extremely broad tuning range can be obtained when the central pump wavelength is in the normal dispersion regime and is insensitive to the wavelength separation between the two pumps, while the tuning range is narrow in the anomalous dispersion regime and can be significantly enhanced by increasing the wavelength separation. Impacts of higher-order dispersions and temporal walk-off on the gain spectra are also discussed.
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Science,ICT&Future Planning(No.NRF-2017R1A1A1A05000762)Cooperative Research Program for Agriculture Science and Technology Development,Rural Development Administration,Republic of Korea(No.PJ01395602 both to JYC)
文摘Beta-nerve growth factor(β-NGF)is known to be a major leading cause of neuronal plasticity.To identify the possible action mechanisms ofβ-NGF gene therapy for sciatic nerve recovery,experimental dogs were randomly divided into control,pyridoxine,and pyridoxine+β-NGF groups.We observed chronological changes of morphology in the dorsal root ganglia in response to pyridoxine toxicity based on cresyl violet staining.The number of large neurons positive for cresyl violet was dramatically decreased after pyridoxine intoxication for 7 days in the dorsal root ganglia and the neuron number was gradually increased after pyridoxine withdrawal.In addition,we also investigated the effects ofβ-NGF gene therapy on neuronal plasticity in pyridoxine-induced neuropathic dogs.To accomplish this,tyrosine kinase receptor A(TrkA),βIII-tubulin and doublecortin(DCX)immunohistochemical staining was performed at 3 days after the last pyridoxine treatment.TrkA-immunoreactive neurons were dramatically decreased in the pyridoxine group compared to the control group,but strong TrkA immunoreactivity was observed in the small-sized dorsal root ganglia in this group.TrkA immunoreactivity in the dorsal root ganglia was similar betweenβ-NGF and control groups.The numbers ofβⅢ-tubulin-and DCX-immunoreactive cells decreased significantly in the pyridoxine group compared to the control group.However,the reduction ofβⅢ-tubulin-and DCX-immunoreactive cells in the dorsal root ganglia in theβ-NGF group was significantly ameliorated than that in the pyridoxine group.These results indicate thatβ-NGF gene therapy is a powerful treatment of pyridoxine-induced neuropathic damage by increasing the TrkA and DCX levels in the dorsal root ganglia.The experimental protocol was approved by the Institutional Animal Care and Use Committee(IACUC)of Seoul National University,South Korea(approval No.SNU-060623-1,SNU-091009-1)on June 23,2006 and October 9,2009,respectively.
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.
文摘The aim of this study is to investigate the effect of chemical extraction method on the properties of doum palm fibres. The method of extraction which is carried out is a soda treatment. First, an investigation of the extraction processes was undertaken. Secondly, the physical properties (surface morphology, density, linear density and diameter), the mechanical properties (tenacity, strain) and chemical properties (FT-IR spectra) of doum palm fibres were inspected. Finally, a comparison between properties of doum palm fibres and other vegetal ones has been included. Results indicates an influence of soda treatment on properties of Doum palm fibers. In fact, there is an improvement on fibers diameter and linear density while increasing soda concentration, temperature and treatment duration. Moreover, the studied fibers have a low density which does not exceed 1. The fibers tenacity achieved the maximum value of 20.86 cN/Tex when precessing in the following combination (0.75 N, 100°C and 180 mn). In the end, the FTIR spectra reveals a change in structure after this alkali treatment while increasing the cellulose amount exposed on the fiber surface and consequently the number of possible reaction sites (OH groups).
文摘This paper focuses on the study of the physical, biochemical, structural, and thermal properties of plant fibres of <i>Rhecktophyllum camerunense</i> (RC), <i>Neuropeltis acuminatas</i> (NA) and <i>Ananas</i> <i>comosus</i> (AC) from the equatorial region of Cameroon. The traditional use of these fibres inspired researchers to investigated their properties. This study aims at improving the state of knowledge with a view to diversifying applications. The fibres are extracted by retting. Then, their apparent density was measured following the ASTM D792 standard and their water moisture absorption and moisture content were also evaluated. Their molecular structure was studied by ATR-FTIR spectroscopy. A quantitative analysis of the biochemical composition was performed according to the analytical technique for the pulp and paper industry (TAPPI). A TGA/DSC analysis was also performed. The results reveal that the AC, NA and RC fibres have densities of 1.26 ± 1.06, 0.846 ± 0.13 and 0.757 ± 0.08 g·cm<sup>-3</sup> respectively. They are also hydrophilic with a water absorption rate of 188.64 ± 11.94%, 276.16% ± 8.07% and 198.17% ± 20%. They have a moisture content of 12.21%, 10.36% and 9.37%. The studied fibres exhibit functional groups that are related to the presence of hemicellulose, pectin, lignin and cellulose. The cellulose crystallinity index was found to be 67.99%, 46.5% and 59.72% respectively. The fibres under study have the following chemical composition: an extractive content of 3.07%, 14.77% and 8.74%;a pectin content of 4.15%, 7.69% and 3.45%;a hemicellulose content of 4.90%, 15.33% and 7.42%;a cellulose content of 68.11%, 36.08% and 65.15%;a lignin content of 12.01%, 25.15% and 16.2%;and an ash content of 0.27%, 1.53% and 0.47% respectively. The thermal transitions observed on the thermograms correlate with the TAPPI chemical composition. It is observed that these fibres are thermally stable up to temperatures of 200°C, 220°C and 285°C. These results make it possible to envisage uses similar to those of sisal, hemp and flax fibres.
基金partly supported by the National Key Basic Research Special Foundation of China (Grant Nos. 2010CB327605 and 2010CB328300)the National High-Technology Research and Development Program of China (Grant No. 2009AA01Z220)+3 种基金the Key Grant of the Chinese Ministry of Education (Grant No. 109015)the Discipline Co-construction Project of Beijing Municipal Commission of Education,China (Grant No. YB20081001301)the Open Fund of Key Laboratory of Information Photonics and Optical Communications (Beijing University of Posts and Telecommunications),Chinese Ministry of Educationthe Specialized Research Fund for the Doctoral Program of Beijing University of Posts and Telecommunications (Grant No. CX201023)
文摘With the full-vector plane-wave method (FVPWM) and the full-vector beam propagation method (FVBPM), the dependences of the band-gap and mode characteristics on material index and cladding structure parameter in anti- resonance guiding photonic crystal fibres (ARGPCFs) are sufficiently analysed. An ARGPCF operating in the near- infrared wavelength is shown. The influences of the high index cylinders, glass interstitial apexes and silica structure on the characteristics of band-gaps and modes are deeply investigated. The equivalent planar waveguide theory is used for analysing such an ARGPCF filled by the isotropic materials, and the resonance and the anti-resonance characteristics r:~n h~ w~|] r^r~dlrtpd
文摘The mechanical and damage properties of single fibres used in fibrous composite have gained tremendous importance in recent years. These properties are used in determination of effective properties of composites by micromechanics. These are also used in the micromechanical damage modeling. Further, these properties are used as an indicator of the excellence of product by manufacturers. In the present study the axial tensile modulus, ultimate strength and failure strain of single fibres are determined for carbon and glass fibres. ASTM D3379-75 standard is followed and a number of fibers are tested for statistical analysis. The axial tensile moduli measured are 246.7 GPa and 93.3 GPa, respectively and strength are 3031.6 MPa and 2035.9 MPa, respectively for carbon and glass fibres. Further, the respective axial tensile failure strains are 0.0137 and 0.0224. The error in the measurement of axial modulus is below 8% while for axial tensile strength is below 1%.
基金funding and support from the Austrian Research Promotion Agency(FFG).
文摘Here,we report the mechanical and water sorption properties of a green composite based on Typha latifolia fibres.The composite was prepared either completely binder-less or bonded with 10%(w/w)of a bio-based resin which was a mixture of an epoxidized linseed oil and a tall-oil based polyamide.The flexural modulus of elasticity,the flexural strength and the water absorption of hot pressed Typha panels were measured and the influence of pressing time and panel density on these properties was investigated.The cure kinetics of the biobased resin was analyzed by differential scanning calorimetry(DSC)in combination with the iso-conversional kinetic analysis method of Vyazovkin to derive the curing conditions required for achieving completely cured resin.For the binderless Typha panels the best technological properties were achieved for panels with high density.By adding 10%of the binder resin the flexural strength and especially the water absorption were improved significantly.
文摘The growing environmental concerns have led to attention on bio-based composite materials, such as the natural fibres, recycled carbon fibres and bio-based resins. Herein, the bio-based epoxy composites were reinforced with ramie fibre (RF) and recycled carbon fibre (rCF) via inter-layer hybridisation. The dynamic mechanical analysis, tensile, flexural and impact properties characterisation were conducted to analyse the mechanical behaviour of the specimens. Also, the morphology of fractured surface after mechanical tests was studied under a scanning electron microscope. When the volume ratio between RF and rCF was varied from 100/0 to 0/100, the flexural and tensile strength of composites was significantly increased, while the impact strength was reduced. Thus the maximum values of flexural strength (182 MPa) and tensile strength (165 MPa) were observed for rCF reinforced composite, whilst impact strength of 24 kJ/m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> was found for RF reinforced composite. Furthermore, the values of storage and loss modulus were increased with the rCF incorporation due to a greater degree of restriction with the addition of rCF into the matrix. The hybridisation was able to combine the specific properties of RF and rCF and optimise the mechanical performance of composites. Therefore, the alternative low-cost green composites are prepared which can replace synthetic materials for semi-structural applications.