Dynamic simulation on the area shrinkage of lower leg for the top part of men’s socks using finite element method

Socks are one of the most important clothes in people’s daily life. This study aimed at the problems existing in the wearing of socks, took the top part of men’s socks as research object, and the contact between human body and socks as elastic contact. The position and shape of skin, soft tissue, and bones in lower leg cross section were acquired through non-contact three-dimensional human scanning and CT scan. Based on these, finite element model of the lower leg cross-section and top part of socks were established for the first time, respectively. Because wearing socks is a continuous process, consequently, we defined the maximum time putting on the sample socks as 12?h in this research work, and then divided the periods of dressing time into six stages, which were instantaneous, 1?h, 2?h, 4?h, 8?h, and 12?h, respectively. After simulating the distribution of pressure and displacement of the top part of socks in dressing using ANSYS software, we divided the lower leg cross section into 12 equal regions according to angle considering the displacement distribution, and then obtained the area shrinkage of each region in six periods of times by calculation. According to the tendency of area shrinkage distribution, the top part of men’s sock could be designed with a different degree of elasticity in diverse regions combined with subjective pressure comfort during the course of sock design. All these solutions are of great significance to the optimization design of socks and can provide theoretical basis for the structural improvement of functional socks and the prediction of clothing pressure.     

Comfort properties of socks from seacell fibers

Since less air circulation occurs at feet in shoes than the other parts of the body, many people have foot-related problems as a result of faulty sock choice. Socks are generally expected to have better comfort properties than the other garments, and accordingly the industry continuously searches for various types of raw materials in order to accomplish the consumers’ comfort-related demands. In this study, our aim was to investigate the comfort properties of socks made from seacell fiber, which has a relatively wide range of application in medical textiles due to its skin and anti-inflammatory properties. For comparison reasons, the comfort properties of socks made from modal, bamboo, soybean cotton, and viscose fibers were also studied. Finally, the hybrid AHP-TOPSIS method was used to decide the best sock option in terms of the properties under discussion.     

银离子的释放及敷料的抗菌性能

为了确定不同的含银医用敷料在银的释放量和释放速度上的区别,分析了几种含银医用敷料释放银离子的性能。介绍了测试抗菌性能的3种方法,并总结了含银医用敷料的抗菌性能及临床疗效。结果显示,不同的伤口对银离子的释放量有不同的要求。烧伤病人的伤口特别容易受感染,因此在烧伤伤口上使用的含银医用敷料的银离子释放量高,在伤口上可以维持较高浓度的银。在高吸湿性的医用敷料中,细菌和伤口渗出液一起被吸进敷料,从敷料上释放出少量的银离子即可达到抗菌的目的。     

Determination of silver release from antibacterial finished cotton and polyester fabrics into water

Silver compounds have extensive use among the antimicrobial agents in textiles. Silver particles are released into the water during washing processes in particular and they are released from the textile in time due to use. In this work, silver ion release from cotton and polyester antimicrobial fabrics which are the most widely used textiles have been studied. Two well-known silver-based commercial agents and silver-doped calcium phosphate powder-based antibacterial finishing agent which was developed in our previous work were applied to the fabric samples. The release of silver from the fabric samples during washing and incubation was determined by ICP-OES. The effects of fabric composition, time and laundering process on the silver release were studied. It was found that significant amount of silver was released from textile fabrics during washing due to the mechanical forces exerted on the fabrics. The total released silver varied from 73.43 to 92.27% for cotton fabrics and 76.49 to 89.70% for PES fabrics after 20 washing cycles. Results also showed that calcium phosphate can reduce the amount of silver release significantly. It was also found that even a smaller quantity of nanosilver particles was sufficient for strong antibacterial activity.     

Exposure modeling of engineered nanoparticles in the environment

The aim of this study was to use a life-cycle perspective to model the quantities of engineered nanoparticles released into the environment. Three types of nanoparticles were studied: nano silver (nano-Ag), nano TiO2 (nano-TiO2), and carbon nanotubes (CNT). The quantification was based on a substance flow analysis from products to air, soil, and water in Switzerland. The following parameters were used as model inputs: estimated worldwide production volume, allocation of the production volume to product categories, particle release from products, and flow coefficients within the environmental compartments. The predicted environmental concentrations (PEC) were then compared to the predicted no effect concentrations (PNEC) derived from the literature to estimate a possible risk. The expected concentrations of the three nanoparticles in the different environmental compartments vary widely, caused by the different life cycles of the nanoparticle-containing products. The PEC values for nano-TiO2 in water are 0.7--16 microg/L and close to or higher than the PNEC value for nano-TiO2 (< 1 microg/L). The risk quotients (PEC/PNEC) for CNT and nano-Ag were much smaller than one, therefore comprising no reason to expect adverse effects from those particles. The results of this study make it possible for the first time to carry out a quantitative risk assessment of nanoparticles in the environment and suggest further detailed studies of nano-TiO2.     

Migration of silver from commercial plastic food containers and implications for consumer exposure assessment

Food storage containers with embedded silver as an antibacterial agent promise longer durability of food. For risk assessment the release of this silver into the stored food and resulting human exposure need to be known. For the purpose of exposure assessment, silver migration from commercial plastic containers with declared content of ‘nano-’ or ‘micro-silver’ into different food simulants (water, 10% ethanol, 3% acetic acid, olive oil) was quantitatively determined by ICP-MS and the form of the released silver was investigated. The highest migration of silver was observed for the acidic food simulant with 30 ng silver cm^?2 contact surface within 10 days at 20°C. In a second and third use cycle, migration dropped by a factor of up to 10, so that the maximum cumulated release over three use cycles was 34 ng cm^?2. The silver release over time was described using a power function and a numerical model that simulates Fickian diffusion through the plastic material. The released silver was found to be in ionic form, but also in the form of silver nanoparticles (around 12%). Consumer exposure to the total amount of silver released from the food containers is low in comparison with the background silver exposure of the general population, but since natural background concentrations are only known for ionic silver, the exposure to silver nanoparticles is not directly comparable with a safe background level.     

基于ABAQUS的运动压力袜编织尺寸预测

为更好地发挥运动压力袜的作用,实现精准施压,使用三维人体扫描仪对人体小腿形态进行扫描,截取脚踝、跟腱与小腿肌转换处、小腿周长最大处以及胫骨初隆处截面曲线;同时运用有限元软件ABAQUS分别建立此 4处截面模型,按照标准值施压,模拟穿着运动压力袜小腿截面的受压状态;分析腿部各截面压力与位移的关系;最后利用运动压力袜编织尺寸的预测模型,设计编织实验样品,进行压力测试分析。结果表明:穿着运动压力袜时,左、右小腿各截面受压状态具有较大差异,但各截面所受压力与产生的位移均呈现一次函数关系;运动压力袜编织尺寸与其压力以及人体腿部截面周长之间,符合二元一次方程关系式;实验样品的压力测试值与标准值的误差均低于5%,证明了此预测模型的有效性。     

保健功能袜品的设计与开发

基于保健功能性产品研发中多种原料与多层结构相结合的设计思路,选用大麻纱、磁性纱、合金锗纱、椰炭纱和莱卡弹性纤维等原料,在电脑织袜机上开发出4款保健功能袜品,并分别测试了它们的色牢度、顶破强力、磁保健功能、远红外加热、负离子释放、抗菌等性能。结果表明:采用功能性纱线结合针织物组织制成的袜品具有一定的保健功能。     

Comparison of a real-time PCR method with a culture method for the detection of Salmonella enterica serotype enteritidis in naturally contaminated environmental samples from integrated poultry houses

Conventional culture methods have traditionally been considered the "gold standard" for the isolation and identification of foodborne bacterial pathogens. However, culture methods are labor-intensive and time-consuming. A Salmonella enterica serotype Enteritidis-specific real-time PCR assay that recently received interim approval by the National Poultry Improvement Plan for the detection of Salmonella Enteritidis was evaluated against a culture method that had also received interim National Poultry Improvement Plan approval for the analysis of environmental samples from integrated poultry houses. The method was validated with 422 field samples collected by either the boot sock or drag swab method. The samples were cultured by selective enrichment in tetrathionate broth followed by transfer onto a modified semisolid Rappaport-Vassiliadis medium and then plating onto brilliant green with novobiocin and xylose lysine brilliant Tergitol 4 plates. One-milliliter aliquots of the selective enrichment broths from each sample were collected for DNA extraction by the commercial PrepSEQ nucleic acid extraction assay and analysis by the Salmonella Enteritidis-specific real-time PCR assay. The real-time PCR assay detected no significant differences between the boot sock and drag swab samples. In contrast, the culture method detected a significantly higher number of positive samples from boot socks. The diagnostic sensitivity of the real-time PCR assay for the field samples was significantly higher than that of the culture method. The kappa value obtained was 0.46, indicating moderate agreement between the real-time PCR assay and the culture method. In addition, the real-time PCR method had a turnaround time of 2 days compared with 4 to 8 days for the culture method. The higher sensitivity as well as the reduction in time and labor makes this real-time PCR assay an excellent alternative to conventional culture methods for diagnostic purposes, surveillance, and research studies to improve food safety.     

Aggregation and dissolution of silver nanoparticles in natural surface water

This study investigated aggregation and silver release of silver nanoparticles suspended in natural water in the absence and presence of artificial sun light. The influence of the capping layer was investigated using uncoated particles and particles coated with citrate or Tween 80. The experiments were conducted over 15 days in batch mode using a river water matrix. Silver release was monitored over this time while the aggregation state and morphological changes of the silver nanoparticles were tracked using dynamic light scattering and transmission electron microscopy. Results indicate sterically dispersed particles coated with Tween released silver quicker than did bare- and citrate-coated particles, which rapidly aggregated. A dissolved silver concentration of 40 μg/L was reached after just 6 h in the Tween-coated particle systems, accounting for ca. 3% of the total silver. Similar levels of dissolved silver were reached in the uncoated and citrate-coated systems at the end of the 15 days. Silver release was not significantly impacted by the artificial sun light; however, the light (and citrate) imparted significant morphological changes to the particles. Their impact was masked by aggregation, which seemed to be the controlling process in this study.     

电发热袜发热区域对足部表面温度的影响

为探究电发热袜发热区域不同时对足部整体及各个区域升温保暖的影响,结合足部的生理特征和袜子的结构特征进行了区域划分,选择了足背前部、足底前部及足底中部3个区域为发热区域,并设计了单区域和双区域发热的6款电发热袜,用红外热像仪和激光多普勒血流检测仪分别探测足部在穿着不同款式电发热袜时各区域表面温度变化和微血管血流量的变化,量化对比足部升温效果。实验结果表明:电发热袜的款式虽有所差异,但均具有一定的保暖效果;发热片对应的足部区域升温最为明显,其次是邻近区域;相比之下足背单区域加热对足血管微循环的影响较小,双区域中足底加热组合比足背与足底加热组合较好。     

基于LabVIEW的袜品压力测试系统开发与应用

开发了一种基于LabVIEW虚拟仪的袜品压力测定系统,探讨不同于服装压力测试的袜品压力测试方法。系统采用轻便、可挠、薄片且灵敏的FlexiForce压力传感器,高精度调理模块处理前端信号,并借助LabVIEW语言开发了可对仪器进行操作的系统应用软件,包括数据的采集、分析、保存、回放等功能。用此系统测量袜子作用于石膏脚模上不同部位的袜压,并结合理论公式分析这几个部位的袜压分布情况,为考察和评价袜子的舒适性提供了新的测试手段。     

Environmental transformations of silver nanoparticles: impact on stability and toxicity

Silver nanoparticles (Ag-NPs) readily transform in the environment, which modifies their properties and alters their transport, fate, and toxicity. It is essential to consider such transformations when assessing the potential environmental impact of Ag-NPs. This review discusses the major transformation processes of Ag-NPs in various aqueous environments, particularly transformations of the metallic Ag cores caused by reactions with (in)organic ligands, and the effects of such transformations on physical and chemical stability and toxicity. Thermodynamic arguments are used to predict what forms of oxidized silver will predominate in various environmental scenarios. Silver binds strongly to sulfur (both organic and inorganic) in natural systems (fresh and sea waters) as well as in wastewater treatment plants, where most Ag-NPs are expected to be concentrated and then released. Sulfidation of Ag-NPs results in a significant decrease in their toxicity due to the lower solubility of silver sulfide, potentially limiting their short-term environmental impact. This review also discusses some of the major unanswered questions about Ag-NPs, which, when answered, will improve predictions about their potential environmental impacts. Research needed to address these questions includes fundamental molecular-level studies of Ag-NPs and their transformation products, particularly Ag(2)S-NPs, in simplified model systems containing common (in)organic ligands, as well as under more realistic environmental conditions using microcosm/mesocosm-type experiments. Toxicology studies of Ag-NP transformation products, including different states of aggregation and sulfidation, are also required. In addition, there is the need to characterize the surface structures, compositions, and morphologies of Ag-NPs and Ag(2)S-NPs to the extent possible because they control properties such as solubility and reactivity.     

纺织服装产品灰水足迹核算与评价研究进展

综述了灰水足迹核算与评价的研究进展,对纺织服装产品灰水足迹核算与评价中涉及的多污染物影响、时间效应、"潜在水环境影响稀释"和区域评价等关键性问题进行了重点讨论.基于纺织服装产品生产排放废水中污染物种类繁多且理化性质复杂的特点,分析得出:进行纺织服装产品灰水足迹核算时仅考虑特征污染物会导致核算结果偏高,应重点关注多种污染...     

Fate of Zinc Oxide Nanoparticles during Anaerobic Digestion of Wastewater and Post-Treatment Processing of Sewage Sludge

The rapid development and commercialization of nanomaterials will inevitably result in the release of nanoparticles (NPs) to the environment. As NPs often exhibit physical and chemical properties significantly different from those of their molecular or macrosize analogs, concern has been growing regarding their fate and toxicity in environmental compartments. The wastewater-sewage sludge pathway has been identified as a key release pathway leading to environmental exposure to NPs. In this study, we investigated the chemical transformation of two ZnO-NPs and one hydrophobic ZnO-NP commercial formulation (used in personal care products), during anaerobic digestion of wastewater. Changes in Zn speciation as a result of postprocessing of the sewage sludge, mimicking composting/stockpiling, were also assessed. The results indicated that "native" Zn and Zn added either as a soluble salt or as NPs was rapidly converted to sulfides in all treatments. The hydrophobicity of the commercial formulation retarded the conversion of ZnO-NP. However, at the end of the anaerobic digestion process and after postprocessing of the sewage sludge (which caused a significant change in Zn speciation), the speciation of Zn was similar across all treatments. This indicates that, at least for the material tested, the risk assessment of ZnO-NP through this exposure pathway can rely on the significant knowledge already available in regard to other "conventional" forms of Zn present in sewage sludge.     

烟叶原料种类对烟草颗粒热解和释烟特性的影响

为揭示颗粒型加热卷烟烟芯材料热解与烟气释放规律,采用湿法造粒技术,利用热重-红外联用装置（TG-FTIR）与锥型量热仪（CONE）,探究了烟叶原料种类对其热解与释烟特性的影响规律。结果表明:①不同种类烟叶原料制备的烟草颗粒失重过程基本一致,相较于烤烟颗粒而言,梗丝、再造烟叶、白肋烟、雪茄烟和香料烟制备的烟草颗粒最大失重速率温度向低温区偏移,且梗丝颗粒和再造烟叶颗粒易挥发性物质释放阶段的失重速率较大,该阶段烤烟颗粒具有最大失重比例,且热解完成后固体残余量最小。②红外光谱结果显示,不同烟叶原料制备的烟草颗粒气相产物释放过程基本一致,因化学成分的差异使得释放温区范围略有差异。其中碳水化合物、酚类和醇类等含羟基化合物的释放温区主要集中在150~300 ℃之间;含C=O的羰基、酯类等化合物以及CO释放过程分为两个阶段,分别为250~400 ℃和500 ℃左右;当温度超过500 ℃时,烟草颗粒热解释放出NH₃和CH₄。③梗丝、再造烟叶以及雪茄烟制备的烟草颗粒的堆积密度约在0.54~0.56 g/cm3之间,相较其他原料而言较小,但烟气释放速率较大,累积释烟总量较高,其中,梗丝颗粒起始释烟速率最大;CO与CO₂释放的整体变化趋势与释烟速率曲线变化规律一致,即释烟速率越大,CO与CO₂的释放速率越大。      

Characterisation and potential migration of silver nanoparticles from commercially available polymeric food contact materials

The potential for consumer exposure to nano-components in food contact materials (FCMs) is dependent on the migration of nanomaterials into food. Therefore, characterising the physico-chemical properties and potential for migration of constituents is an important step in assessing the safety of FCMs. A number of commercially available food storage products, purchased domestically within the United States and internationally, that claim to contain nanosilver were evaluated. The products were made of polyethylene, polypropylene and polyphenylene ether sulfone and all contained silver (0.001–36 mg kg^–1 of polymer). Silver migration was measured under various conditions, including using 3% acetic acid and water as food simulants. Low concentrations (sub-ppb levels) of silver were detected in the migration studies generally following a trend characterised by a surface desorption phenomenon, where the majority of the silver migration occurred in the first of three consecutive exposures. Silver nanoparticles were not detected in food simulants, suggesting that the silver migration may be due solely to ionic silver released into solution from oxidation of the silver nanoparticle surface. The absence of detectable silver nanoparticles was consistent with expectations from a physico-chemical view point. For the products tested, current USFDA guidance for evaluating migration from FCMs was applicable.     

Relative solubility of cations in Class F fly ash

Coal utilization byproducts (CUB), such as fly ash, contain cations that may be released during exposure to fluids such as acid rain or acid mine drainage. Researchers at the Department of Energy's National Energy Technology Laboratory (DOE/NETL) have conducted a long-term column leaching study of 32 Class F fly ash samples from pulverized coal (PC) combustion, and quantified the release of 19 cations in four leachants with a pH between 1.2 and 12. The relative solubility (M(L/T)) of each cation was defined as the total mass leached (M(L)) relative to the concentration (M(T)) of that element in the fly ash sample. A frequency distribution of relative solubility values was computed with ranges defined as insoluble, slightly soluble, moderately soluble, and very soluble. On the basis of this sample set, Ba, Cd, Fe, Pb, Sb, and Se in PC fly ash are insoluble. The elements Al, Be, Ca, Co, Cr, Cu, K, Mg, Mn, Na, Ni, and Zn are slightly to moderately acid soluble. Only Ca and Na are water soluble; As and Ca are soluble in the basic solution, The results of this study indicate that the extent to which cations in Class F PC fly ash can be leached by naturally occurring fluids is very limited.     

Potential environmental impacts of light-emitting diodes (LEDs): metallic resources, toxicity, and hazardous waste classification

Light-emitting diodes (LEDs) are advertised as environmentally friendly because they are energy efficient and mercury-free. This study aimed to determine if LEDs engender other forms of environmental and human health impacts, and to characterize variation across different LEDs based on color and intensity. The objectives are as follows: (i) to use standardized leachability tests to examine whether LEDs are to be categorized as hazardous waste under existing United States federal and California state regulations; and (ii) to use material life cycle impact and hazard assessment methods to evaluate resource depletion and toxicity potentials of LEDs based on their metallic constituents. According to federal standards, LEDs are not hazardous except for low-intensity red LEDs, which leached Pb at levels exceeding regulatory limits (186 mg/L; regulatory limit: 5). However, according to California regulations, excessive levels of copper (up to 3892 mg/kg; limit: 2500), Pb (up to 8103 mg/kg; limit: 1000), nickel (up to 4797 mg/kg; limit: 2000), or silver (up to 721 mg/kg; limit: 500) render all except low-intensity yellow LEDs hazardous. The environmental burden associated with resource depletion potentials derives primarily from gold and silver, whereas the burden from toxicity potentials is associated primarily with arsenic, copper, nickel, lead, iron, and silver. Establishing benchmark levels of these substances can help manufacturers implement design for environment through informed materials substitution, can motivate recyclers and waste management teams to recognize resource value and occupational hazards, and can inform policymakers who establish waste management policies for LEDs.     

剑麻载银复合抗菌纤维的制备及其性能

以自制纳米银粒子为抗菌剂,基于膜自组装原理,采用Nβ--(氨乙基)-γ-氨丙基甲基二甲氧基硅烷偶联剂(YDH602)为架桥剂,制备了键合型载银剑麻复合抗菌纤维。以纤维载银量为指标,考察了纳米银溶胶质量浓度、反应时间、pH值对载银效果的影响。利用TEM、紫外光谱仪、SEM、X-射线能谱仪等对纳米银粒子和剑麻抗菌纤维结构进行了表征。结果表明,所制备的剑麻抗菌纤维载银量较多,并且分布比较均匀,在48 h内,银释放量为0.17%,说明银与剑麻的结合能力较强,并且会持续稳定地释放出银。此外,载银剑麻纤维对金黄色葡萄球菌和肺炎克雷伯菌的抗菌效果较好。