A Cell-Based Smoothed Finite Element Method for Modal Analysis of Non-Woven Fabrics

The combination of a 4-node quadrilateral mixed interpolation of tensorial components element(MITC4)and the cell-based smoothed finite element method(CSFEM)was formulated and implemented in this work for the analysis of free vibration and unidirectional buckling of shell structures.This formulation was applied to numerous numerical examples of non-woven fabrics.As CSFEM schemes do not require coordinate transformation,spurious modes and numerical instabilities are prevented using bilinear quadrilateral element subdivided into two,three and four smoothing cells.An improvement of the original CSFEM formulation was made regarding the calculation of outward unit normal vectors,which allowed to remove the integral operator in the strain smoothing operation.This procedure conducted both to the simplification of the developed formulation and the reduction of computational cost.A wide range of values for the thickness-to-length ratio and edge boundary conditions were analysed.The developed numerical model proved to overcome the shear locking phenomenon with success,revealing both reduced implementation effort and computational cost in comparison to the conventional FEM approach.The cell-based strain smoothing technique used in this work yields accurate results and generally attains higher convergence rate in energy at low computational cost.

Relationship between Light Scattering Intensity and Basis Weight of Non-Woven Fabrics

The relationship between light scattering intensity and basis weight of nonwoven fabrics is studied by using the theory of electromagnetic wave propagation and scatter-ing in random media.The theoretical analysis shows that the backscattering intensity of nonwoven fabric is closely related to its basis weight,and 2 series nonwoven samples manufactured by spun-bonded and thermal-bounded processing methods are tested for checking the theoretical expression.The study shows that the scattering intensity increases with increasing basis weight of nonwoven fabrics in exponential equation,and theoretical expression is consistent with the experimental data.

TiO_2/Polyester Non-woven Fabrics as a Kind of Photocatalyst for the Degradation of Formaldehyde Gas

The feasibility of photocatalytic degradation of the formaldehyde gas by titanium dioxide （TiO2）/polyester non-woven fabrics was studied. Tbe effects of parameters such as tbe concentration of TiO2 solution, pH value, and drying temperature on the photocatalytic degradation of the formaldehyde gas were also studied. The results showed that the photodegradation efficiency of the formaldehyde gas increased rapidly with the increasing of the concentration of TiO2 solution up to 15g/L, but when the concentration was in excess of 15g/L, the photodegradation efficiency decreased gradually and fluctuated due to light obstruction and disperse state of TiO2. Adjusting the pH value in the solution, the efficiency of photocatalytic degradation of the formaldehyde gas could be improved. The mechanisms of the reaction and the role of the additives were also investigated. After 42hours, TiO2/ polyester non-woven fabric showed no significant loss of the photocatalytic activity.

Single-wall carbon nanotube fiber non-woven fabrics with a high electrothermal heating response

Carbon nanotube(CNT)fibers have great promise for constructing multifunctional fabrics with high electrical conductivity,good electro-heating ability,excellent flexibility,and a low density.However,the inter-fiber contacts in the fabric greatly reduce these advantages and limit their application.Herein,a simple pressure-fusing method to fabricate single-wall CNT(SWCNT)fiber non-woven fabrics(NWFs)that are composed of interconnected SWCNT fibers with fused joints is reported,which have good flexibility,a low density of 0.46 g/cm^(3),a high electrical conductivity of 3.7×10^(5)S/m,and a record high specific electrical conductivity of 803(S·m^(2))/kg.They also showed excellent electrical heating ability,so that a temperature of~160℃was rapidly reached at a low voltage of 2 V.Combined with their low density,the SWCNT fiber NWFs are promising for use as a heating unit for low temperature battery protection and de-icing applications.

Smart Cellulose‑Based Janus Fabrics with Switchable Liquid Transportation for Personal Moisture and Thermal Management

The Janus fabrics designed for personal moisture/thermal regulation have garnered significant attention for their potential to enhance human comfort.However,the development of smart and dynamic fabrics capable of managing personal moisture/thermal comfort in response to changing external environments remains a challenge.Herein,a smart cellulose-based Janus fabric was designed to dynamically manage personal moisture/heat.The cotton fabric was grafted with N-isopropylacrylamide to construct a temperature-stimulated transport channel.Subsequently,hydrophobic ethyl cellulose and hydrophilic cellulose nanofiber were sprayed on the bottom and top sides of the fabric to obtain wettability gradient.The fabric exhibits anti-gravity directional liquid transportation from hydrophobic side to hydrophilic side,and can dynamically and continuously control the transportation time in a wide range of 3–66 s as the temperature increases from 10 to 40℃.This smart fabric can quickly dissipate heat at high temperatures,while at low temperatures,it can slow down the heat dissipation rate and prevent the human from becoming too cold.In addition,the fabric has UV shielding and photodynamic antibacterial properties through depositing graphitic carbon nitride nanosheets on the hydrophilic side.This smart fabric offers an innovative approach to maximizing personal comfort in environments with significant temperature variations.

A new kind of resin-based wet friction material:Non-woven fabrics with isotropic fiber networks as preforms

As an alternative to short fibers,non-woven fabrics(NWFs)were made using different types of long fibers to optimize the performance of paper-based friction materials and their technology.In this investigation,the fillers and resin were impregnated into these NWFs to prepare three kinds of wet friction material.The tribological,mechanical,and thermal properties of the new wet friction material were studied.The results indicate that the dynamic friction coefficient of the new friction material is approximately 0.12 and the static friction coefficient is approximately 0.15;the better wear rate is 0.81334×10^(-14)m^(3)·(N·m)^(-1).In addition,the temperature for 10%mass loss yielded 100°C enhancement and the tensile strength was improved by 200%,compared to previously reported values.Most importantly,the advantages include a simple preparation flow,low cost,and resource conservation.This is a promising approach for the future development of paper-based friction materials.

Comparative Study of Polypropylene Non-Woven Surgical Mask and Locally Manufactured Woven and Knitted Fabrics Facial Masks

The outbreak of coronavirus has led to an increase in the demand for facemasks globally. Unavailability of appropriate polypropylene non-woven fabrics face masks as a result of inadequate supply to satisfy the growing population has brought about the manufacturing of locally fabrics masks to augment or substitute standard medical class facemasks. The study aims at analyzing airflow of these locally manufactured fabrics to determine possible means of transmitting the virus as well as establish comfort of the user of these masks. Standard polypropylene non-woven, woven and knitted fabrics were considered for the study. Air permeability test was conducted on these fabrics using Frazier Air permeability tester. Depending on the property significant variation in the textile fabrics, polypropylene non-woven is widely accepted for facial masks. Nevertheless, this study illustrates that woven and knitted fabrics have more open structures, which allow a high rate of air penetration and so may require two or three layers to prevent antimicrobial or antiviral potential.

Robust,Flexible,and Superhydrophobic Fabrics for High-Efficiency and Ultrawide-Band Microwave Absorption

Microwave absorption(MA)materials are essential for protecting against harmful electromagnetic radiation.In this study,highly efficient and ultrawide-band microwave-absorbing fabrics with superhydrophobic surface features were developed using a facile dip-coating method involving in situ graphene oxide(GO)reduction,deposition of TiO_(2) nanoparticles,and subsequent coating of a mixture of polydimethylsiloxane(PDMS)and octadecylamine(ODA)on polyester fabrics.Owing to the presence of hierarchically structured surfaces and low-surface-energy materials,the resultant reduced GO(rGO)/TiO_(2)-ODA/PDMS-coated fabrics demonstrate superhydrophobicity with a water contact angle of 159°and sliding angle of 5°.Under the synergistic effects of conduction loss,interface polarization loss,and surface roughness topography,the optimized fabrics show excellent microwave absorbing performances with a minimum reflection loss(RL_(min))of47.4 dB and a maximum effective absorption bandwidth(EAB_(max))of 7.7 GHz at a small rGO loading of 6.9 wt%.In addition,the rGO/TiO_(2)-ODA/PDMS coating was robust,and the coated fabrics could withstand repeated washing,soiling,long-term ultraviolet irradiation,and chemical attacks without losing their superhydrophobicity and MA properties.Moreover,the coating imparts self-healing properties to the fabrics.This study provides a promising and effective route for the development of robust and flexible materials with microwave-absorbing properties.

Engineering graphene oxide and hydrogel coatings on fabrics for smart Janus textiles with superior thermal regulation

Fabric multifunctionality offers resource savings and enhanced human comfort.This study innovatively integrates cooling,heating,and antimicrobial properties within a Janus fabric,surpassing previous research focused solely on cooling or heating.Different effects are achieved by applying distinct coatings to each side of the fabric.One graphene oxide(GO)coating exhibits exceptional light-to-heat conversion,absorbing and transforming light energy into heat,thereby elevating fabric temperature by 15.4℃,22.7℃,and 43.7℃ under 0.2,0.5,and 1 sun irradiation,respectively.Conversely,a hydrogel coating on one side absorbs water,facilitating heat dissipation through evaporation upon light exposure,reducing fabric temperature by 5.9℃,8.4℃,and 7.1℃ in 0.2,0.5,and 1 sun irradiation,respectively.Moreover,both sides of Janus fabric exhibit potent antimicrobial properties,ensuring fabric hygiene.This work presents a feasible solution to address crucial challenges in fabric thermal regulation,providing a smart approach for intelligent adjustment of body comfort in both summer and winter.By integrating heating and cooling capabilities along with antimicrobial properties,this study promotes sustainable development in textile techniques.

Matching Dyeing and Properties of Silk Fabrics with Natural Edible Pigments

The silk fabrics were matching dyed with three natural edible pigments(red rice red,ginger yellow and gardenia blue).By investigating the dyeing rates and lifting properties of these pigments,it was observed that their compatibilities were excellent in the dyeing process:dye dosage 2.5%(omf),mordant alum dosage 2.0%(omf),dyeing temperature 80℃and dyeing time 40 min.The silk fabrics dyed with secondary colors exhibited vibrant and vivid color owing to the remarkable lightness and chroma of ginger yellow.However,gardenia blue exhibited multiple absorption peaks in the visible light range,resulting in significantly lower lightness and chroma for the silk fabrics dyed with tertiary colors,thus making it suitable only for matte-colored fabrics with low chroma levels.In addition,the silk fabrics dyed with these three pigments had a color fastness that exceeded grade 3 in resistance to perspiration,soap washing and light exposure,indicating acceptable wearing properties.The dyeing process described in this research exhibited a wide range of potential applications in matching dyeing of protein-based textiles with natural colorants.

Preparation of Durable Antibacterial Polyester Fabrics by Grafting with the Natural Quaternary Ammonium Compound Betaine

Recently, the textile industry has increasingly advocated for natural resource-based healthcare textiles. This research presents a facile and eco-friendly approach to developing durable antibacterial polyester fabrics. Polyester fabric was first subjected to an alkaline hydrolysis to impart hydroxyl groups on the fiber surface. A natural antibacterial agent, betaine, was then covalently bonded to the hydrolyzed polyester fiber surface through esterification. XPS, Raman, SEM, and Wicking measurements were carried out to verify the esterification reaction. Antibacterial tests confirmed that betaine treatment grafted polyester fabrics revealed a remarkable antibacterial effect with inhibition rates > 99.9% against both E. coli and S. aureus and still remained inhibition rates of up to 91.5% against both bacteria after home washing for 20 cycles. Moreover, the modification significantly increased the capillary effect of polyester fabric but did not cause apparent adverse effects on the fabric’s hand or tensile strength. Overall, this grafting strategy for durable, antibacterial polyester fabric represents a significant practicality in the textile industry.

Evaluation of Nylon 6 and Nylon 66 Cord Fabrics for Scooter Tyre Production under Different Curing Conditions

Cord fabric is a critical material used in the manufacture of tyres and various composite materials to increase durability and strength. The tyre consists of many layers of cord fabric, with each layer being referred to as a cord ply. These layers are strategically positioned within the tyre’s internal structure, particularly in the tread and sidewall areas, to improve handling, durability and impact resistance. The cord fabric also serves a critical role in maintaining the structural integrity of the tyre, ensuring that it retains its contour and resists deformations under different operating conditions. This study discusses the advantages and disadvantages of using Nylon 6 (NY6) and Nylon 66 (NY66) cord fabrics in scooter tire production, with a focus on their mechanical behavior under varying curing temperatures and pressures. It was observed that while the curing time for both NY6 and NY66 remained consistent across different platen temperatures and pressures, their mechanical properties showed significant differences. NY6, known for its flexibility and impact resistance, exhibited greater changes in cord-breaking strength and elongation with increasing temperature, showing a marked decrease in breaking strength at higher temperatures. In contrast, NY66 maintained better stability and performance under similar conditions.

Predicting the Stitch Density of Finished Fabrics Using Weft Blended Grey Knit Fabrics

Stitch density is one of the critical quality parameters of knit fabrics. This parameter is closely related to other physical quality parameters like fabric weight, fabric tightness factor, fiber types, blend ratio, yarn diameter and linear density, and fabric structure. Selecting stitch density (wales per inch, course per inch) is essential to getting the appropriate fabric weight and desired quality. Usually, no rules or assumptions exist to get the desired stitch density in the finished fabric stage. Fifteen types of blended knit fabrics were prepared to conduct the study. The varying percentages of cotton, polyester, and elastane are incorporated in the blends. Regression analysis and regression ANOVA tests were done to predict the stitch density of finished fabrics. A suitable regression equation is established to get the desired results. The study also found that the stitch density value in the finished stage fabric decreases by approximately 15% compared to the stitch density in the grey fabric stage. This study will help the fabric manufacturers get the finished fabric stitch density in advance by utilizing the grey fabric stitch density data set. The author expects this research to benefit the knitting and dyeing industry, new researchers, and advanced researchers.

Composite polymer electrolyte membranes supported by non-woven fabrics for lithium-ion polymer batteries

Poly(vinylidene fluoride-co-hexafluoropropyle- ne) (PVDF-HFP) is one of the most popular polymers for polymer electrolyte membranes because of its excellent oper- ating characteristics and superior electrochemical properties. The electrochemical performances of polymer electrolyte membrane can be enhanced by evenly dispersing nano-meter SiO2 particles in the polymer. In this paper, non-woven fab- rics were immersed in the mixed solution of PVDF-HFP/ SiO2/butanone/butanol/plasticizer, and then dried in a vac- uum oven to remove the solvents and the plasticizer and to make porous composite polymer electrolyte membranes. The prepared composite membranes supported by non-woven fabrics boast good mechanical strength and excellent elec- trochemical properties: the electrochemical stability window is 4.8 V vs. Li+/Li, and the ionic conductivity is 3.35×10?4 S/cm (around 60% of that of a common PE membrane) at room temperature. The lithium-ion polymer battery assem- bled by the composite membrane exhibits high rate capabil- ity and excellent cycling performance.

Influence of pyrolytic carbon coatings on complex permittivity and microwave absorbing properties of Al_2O_3 fiber woven fabrics

The pyrolytic carbon （PyC） coatings were fabricated on A1203 fiber fabrics by the method of chemical vapor deposition （CVD）. The microstructures of A1203 fibers with and without PyC coatings were characterized by SEM and Raman spectroscopy. The influence of deposition time of PyC on the DC conductivity （ad） of A1203 filaments and complex permittivity of fabrics at X band （8.2-12.4 GHz） were investigated. The values of Crd and complex permittivity increase with increasing deposition time of PyC. The electron relaxation polarization and conductance loss were supposed to be contributed to the increase of ε＇ and ε＂, respectively. In addition, the reflection loss （RL） of fabrics was calculated. The results show that the microwave absorbing properties of Al2O3 fiber fabrics can be improved by PyC coatings. The best RL results are for 60 min-deposition sample, of which the minimum value is about -40.4 dB at about 9.5 GHz and the absorbing frequency band （AFB） is about 4 GHz.

一种面向联盟链Hyperledger Fabric的并发冲突事务优化方法

随着区块链技术应用的普及,联盟链Hyperledger Fabric(简称Fabric)已成为知名区块链开源平台,并得到广泛关注.然而Fabric仍受困于并发事务间冲突问题,冲突发生时会引发大量无效交易上链,导致吞吐量下降,阻碍其发展.对于该问题,现有面向块内冲突的方案缺乏高效的冲突检测和避免方法,同时现有研究往往忽略区块间冲突对吞吐量的不利影响.提出了一种Fabric的优化方案Fabric-HT(fabric with high throughput),从区块内和区块间2方面入手,有效降低事务间并发冲突和提高系统吞吐量.针对区块内事务冲突,提出了一种事务调度机制,根据块内冲突事务集定义了一种高效数据结构——依赖关系链,识别具有“危险结构”的事务并提前中止,合理调度事务和消除冲突;针对区块间事务冲突,将冲突事务检测提前至排序节点完成,建立以“推送-匹配”为核心的冲突事务早期避免机制.在多场景下开展大量实验,结果表明Fabric-HT在吞吐量、事务中止率、事务平均执行时间、无效事务空间占用率等方面均优于对比方案.Fabric-HT吞吐量最高可达Fabric的9.51倍,是最新优化方案FabricSharp的1.18倍;空间利用率上相比FabricSharp提升了14%.此外,Fabric-HT也表现出较好的鲁棒性和抗攻击能力.

基于Fabric的海量交易数据上链预处理机制

Hyperledger Fabric是一种国内外广泛使用的联盟链框架,在基于Fabric技术的一些业务中具有协同组织众多、交易操作频繁、事务冲突增加等特点。Fabric采用的多版本并发控制技术能够在一定程度上解决部分交易冲突,提升系统并发性,但其机制不完善,会出现部分交易数据无法正常上链存储的问题。为了实现海量交易数据完整、高效、可信的上链存储,提出一种基于Fabric预言机的数据上链预处理机制。设计海量数据冲突预处理(MCPP)方法,通过检测、监听、延时提交、事务加锁、重排序缓存等方式实现主键冲突交易数据的完整上链。引入数据传输保障措施,在传输过程中利用非对称加密技术防止恶意节点伪造认证信息,确保交易数据链外处理前后的一致性。通过理论分析和实验结果表明,该机制可有效解决联盟链平台中海量交易数据上链时的并发冲突问题,当交易数据规模达到1 000和10 000时,MCPP的时效性比LMLS提高了38%和21.4%,且成功率接近100%,具有高效性和安全性,同时在无并发冲突情况下不影响Fabric系统性能。

High Temperature Strain Structures and Quartz C-Axis Fabrics from Mylonitic Rocks in the Ailaoshan-Red River Shear Zone,Yunnan,and Their Tectonic Implication

The Ailaoshan-Red River（ASRR） shear zone is one of the major Southeast Asian tectonic discontinuities that have figured the present tectonic framework of the eastern Tibet.Several metamorphic massifs are distributed linearly along the shear zone,e.g.Xuelongshan,Diancangshan, Ailaoshan and Day Nui Con Voi from north to south.They bear a lot of lines of evidence for the tectonic evolution of the eastern Tibetan at different crustal levels in different tectonic stages.Controversy still exists on the deformation structures,microstructures and their relationship with metamorphisms along the ASRR.In this paper detailed microstructural and EBSD（Electron Backscattered Diffraction） fabric analysis of some highly sheared granitic rocks from different massifs along the ASRR are conducted.High temperature structures and microstructures are preserved in unsheared gneisses,in weakly sheared xenoliths or in some parts of the highly sheared rocks（mylonites）.Several types of high temperature quartz c-axis fabrics show symmetrical patterns or transitions from symmetrical to asymmetrical patterns.The former are attributed to coaxial deformation during regional shortening in an early stage of the Indian-Eurasian tectonic interaction and the latter are related to the transitions from coaxial compression to noncoaxial shearing during the post-collisional ASRR left lateral shearing.

基于CP-ABE算法的Fabric隐私保护模型

传统区块链系统缺少对区块数据的隐私保护。结合CP-ABE(基于属性加密的密文策略)算法和IPFS(星际文件系统),提出一种可以对Fabric区块链实现访问控制的隐私保护模型CP-PPM。CP-PPM的数据所有者可以灵活设置访问控制策略。仿真结果表明,与现有Fabric区块链系统相比,CP-PPM模型支持细粒度的访问控制,具有更强的隐私保护效果;CP-ABE算法可以安全初始化,对数据的加解密效率更高,同时增强了区块链系统的存储性能。

Research on Properties of Woven Fabrics Treated by High Pressure Water Jet

The paper introduces a new technique for the treatment of the woven fabrics. Sprayed by high pressure water jet, the appearance, handle and stiffness of the fabric are improved. Other properties of the high pressure water treated fabrics like drape coefficient, air permeability, tenacity are also presented.