Heat strain in chemical protective clothing in hot-humid environment:Effects of clothing thermal properties

Heat strain experienced by individuals wearing chemical protective clothing(CPC)is severe and dangerous especially in hot-humid environment.The development of material science and interdisciplinary studies including ergonomics,physiology and heat transfer is urgently required for the reduction of heat strain.The aim of this paper was to study the relationship among clothing thermal properties,physiological responses and environmental conditions.Three kinds of CPC were selected.Eight participants wore CPC and walked(4 km/h,two slopes with 5%and 10%)on a treadmill in an environment with(35±0.5)℃ and RH of(60±5)%.Core temperature,mean skin temperature,heart rate,heat storage and tolerance time were recorded and analyzed.Physiological responses were significantly affected by the clothing thermal properties and activity intensity in hot-humid environment.The obtained results can help further development of heat strain model.New materials with lower evaporative resistance and less weight are necessary to release the heat strain in hot-humid environments.

Study on Protective Clothing against SARS Using PTFE/Poly(ether-ester) Membrane

By means of texturing with organic conductive fiber, and then being treated with JAM-Y1 anti-bacteria agent, in the end, treated with the XL-550 waterproof agent, the PET fabric has permanent antistatic, anti-bacteria and waterproof and anti-oil properties. The PET fabric was laminated with PTFE membrane by paste dot coating, and then coated by Poly(ether-ester) solution in a direct process. The filter efficiency of NaCl aerosol, penetration property of poliomyelitis virus in liquid and animalcule in air of PET fabric laminated with PTFE membrane are measured. The properties show that the PET fabric laminated with PTFE membrane can separate SARS virus in air and liquid. The protective mechanism is also discussed in the article.

Structure and Properties of Polytetrafluorethylene and Polyurethane Layered Membrane for Protective Clothing

This paper presents a new idea for intensifying protective and stretch recovery properties of micro porous polytetrafluorethylene and hydrophilic polyurethane (PTFE/PU) layered membrane through a co-stretching process. The structure and properties of co-stretching PTFE/PU layered membrane and coated PTFE/PU layered membrane by means of directly coating the PU on the PTFE membrane were investigated using Electron Microscope, Universal Materials Testing Machine, and the water vapor permeability (WVP) was measured according to absorption method of water vapor of GB/T 12704-91. Contrasted to PU coating process, the PU membrane on the co-stretching PTFE/PU membrane is nonporous because of heat treatment process, which can prevent the SARS virus from permeating the Co-stretching PTFE/PU membrane. The stretch and recovery properties of the Co-stretching PTFE/PU membrane is at least 66% after being stretched to 50% of its original length in transverse directions and that of the coated PTFE/PU membrane is 52%. The WVP of the Co-stretching PTFE/PU membrane is 13 523 g/24 h·m^2. The results suggest that when Co-stretching PTFE/PU membrane is laminated to a stretchable fabric, the fabric would have excellent stretch and recovery properties while waterproof and being permeable to water vapor. So, the Co-stretching PTFE/PU membrane laminated fabric will be a comfortable protective clothing material.

Numerical Estimation of the Thermal Response of Thermal Protective Clothing-Air Gap-Human Skin Micro-system

Thermal protective clothing has been recognized as the primary shielding against emergency fire hazard and inflammable gas leakage. Therefore,the thermal response of human covered with thermal protective clothing under high temperature is the key work to investigate the thermal insulation of thermal protective clothing. A coupling model composed of thermal protective clothing,air gap and human skin is established and the temperature of the micro-system is numerically solved via the finite element method( FEM).Especially,the heat transfer of air gap located between clothing and human skin considering conduction and radiation is established while the human skin layers involve the effect of blood perfusion. Then the effect of thermophysical properties( thermal conductivity and volumetric capacity) of fabric and thickness of fabric and air on the thermal response of the micro-system is elucidated and compared.The results indicate that the volumetric heat capacity of fabric is the key parameter to affect the thermal shielding performance of thermal protective clothing,and the thicker fabric thickness and air gap thickness can improve the thermal protective properties of the micro-system.

Development of a Reproducible Rating System for Sun Protective Clothing That Incorporates Body Surface Coverage

Sunlight is a known skin carcinogen. Skin cancer is the most common form of cancer in humans, and typically affects sun-exposed parts of the body. Sunny Australia and New Zealand have the highest incidence of skin cancer globally. Clothing provides a protective barrier that reduces the amount of ultraviolet radiation (UVR) reaching the skin. Australia pioneered the development of a relative ranking of the sun-protective capabilities of clothing based on the transmission of UVR through fabric. Standardized Ultraviolet Protection Factor (UPF) measurement procedures and associated labeling specifications are documented in the Australian and New Zealand Standard, AS/NZS 4399:1996. The standard was intended to enable consumers to make informed choices. Since its introduction, this standard has been adopted almost universally by the textile industry, and is still in use almost two decades on, with plans to revise it only commencing recently. However, AS/NZS 4399:1996 does not consider garment design, particularly in relation to body surface coverage. Although swim-shirts have grown in popularity in Australia since the late 1990s, particularly among children, clothing remains under-utilized as a form of sun-protection in contemporary society. Skin cancer prevention campaigns should emphasize the sun-protective benefits of clothing and collaboration with the fashion industry is urgently needed to improve the aesthetic appeal, comfort, durability and affordability of sun-protective clothing to increase its popularity in skin cancer prone populations. In light of recent evidence showing that high UPF clothing which covers more of the body surface reduces pigmented mole development in children (major risk factor for melanoma), the rating system for sun-protective clothing should incorporate body surface covered as well as the UPF of the fabric. We discuss progress towards developing a protocol for measuring the extent of coverage of sun-protective garments. Once fully evaluated and refined, the testing protocol developed from this research may influence future revisions of international standards for evaluating and classifying sun-protective clothing.

Research on the Copyright Protection Technology of Digital Clothing Effect Diagram

As a kind of digital clothing design works,digital clothing effect diagram shows fast and roughly designer intent expression and needs protection of digital copyright protection technology.A novel digital clothing effect diagram copyright protection scheme and some algorithms based on digital image watermark technology are proposed,used by two-dimensional chaotic encryption watermark generation algorithm to generate watermark data,watermark embedding algorithm twice using genetic algorithm to obtain the optimal embedding position and embedding strength,and watermark verification algorithm to determine the copyright ownership.Experimental results and analyses show that the proposed scheme and algorithms have the feasibility and effectiveness.

Effect of Phase Change Materials on the Thermal Protective Performance of the Multi-layered Fabrics Examined by TPP Tester under Flash Fire

Cotton fabrics treated with phase change materials( PCMs)were used in multi-layered fabrics of the fire fighter protective clothing to study its effect on thermal protection. The thermal protective performance( TPP) of the multi-layered fabrics was measured by a TPP tester under flash fire. Results showed that the utilization of the PCM fabrics improved the thermal protective performance of the multi-layered fabrics. The fabric with a PCM add on of 41. 9% increased the thermal protection by 50. 6% and reduced the time to reach a second degree burn by 8. 4 s compared with the reference fabrics( without PCMs). The employment of the PCM fabrics also reduced the blackened areas on the inner layers. The PCM fabrics with higher PCM melting temperature could bring higher thermal protective performance.

Effect of Air Gap under Fabric on Thermal Protective Performance Using an Improved Apparatus

The bench top test is one of the most important and effective methods to evaluate the total thermal protective performance(TPP) of firefighters' protective clothing,which is greatly influenced by the air gaps entrapped.In this paper,to investigate the effect of air gap width on TPP,a new improved apparatus with two height changeable buttons to hold the thermal sensor was developed to get a series of air gap sizes from 0 mm to 40 mm.The TPP of two types of flame-resistant outer fabrics was measured with TPP test apparatus respectively.Analysis of temperature rise with each air gap width was made to determine the effects of different air gaps on protective performance.It was indicated that air gap size had great effect on TPP of fabrics in the bench top test.An air gap width above 8 mm was suggested for the thermal protective clothing design.

Radiation Protection of a Patient Undergoing an Orthopedic Procedure by Using a Mobile C-Arm X-Ray System

Modern medicine is unthinkable without X-rays. Accurate diagnosis, leading to effective treatment, is largely based on precise X-ray examinations. The creation of new, modern equipment and various medical procedures that meet the increased requirements are a priority in our time. X-ray examinations are of particular importance for the orthopedic and traumatological clinics, where they provide information about presence of a fracture in the patient’s body, about the concrete operation performed or about the effect of a suitable treatment. Along with their benefits X-rays have also a harmful effect. This requires special care to protect from this radiation. In this direction, research is constantly being done to improve the quality of radiation protection. Park MR, Lee KM and co-authors, compare the dose load obtained using C-arm and O-arm X-ray systems (which have the capability of combined 2D fluoroscopy and 3D computed tomography imaging). In their study, an orthopedic surgical procedure using C-arm and O-arm systems in 2D fluoroscopy modes was simulated. The radiation doses to susceptible organs of the operators were investigated. He results obtained show that the O-arm system delivered higher doses to the sensitive organs of the operator in all configurations [1]. The article of Stephen Balte briefly reviews the available technologies for measuring or estimation of patient skin dose in the interventional fluoroscopic environment, created by various X-ray equipment including C-arm systems. Given that many patients require multiple procedures, this documentation also aids in the planning of follow up visits [2]. Chong Hing Wong, Yoshihisa Kotani and co-authors evaluate the radiation exposures (RE) to the patient and surgeon during minimally invasive lumbar spine surgery with instrumentation using C-arm image intensifier or O-arm intraoperative CT. The results they get are in favor of the O-arm system [3]. The article “Virtual fluoroscopy for intraoperative C-arm positioning and radiation dose reduction” discusses positioning of an intraoperative C-arm system to achieve clear visualization of a particular anatomical feature by a system for virtual fluoroscopy (called FluoroSim) that could dramatically reduce time and received dose during the procedures. FluoroSim was found to reduce the radiation exposure required for C-arm positioning without reducing positioning time or accuracy, providing a potentially valuable tool to assist surgeons [4]. In our study, we performed practical measurements to show how the patient can be treated by applying most effective radiation protection when using a mobile C-arm X-ray system. For the study, we used exposure upon a phantom placed on the patient’s table. For an X-ray shielding, we used a protective apron with a lead equivalent of 1 mm, placed in two layers on the phantom. In each subsequent series of exposures, the protective apron was placed on the phantom, in a different position relative to the X-ray beam. The general conclusion of our study is that in order to obtain maximum protection from scattered radiation when using C-arm X-ray systems, the patient must be protected by a shielding with a suitable lead equivalent for the procedure performed which must be placed between patient’s body and X-ray tube, perpendicular to the X-ray beam pointed toward the region of interest.

Validity of a noninvasive estimation of deep body temperature when wearing personal protective equipment during exercise and recovery

Background:Deep body temperature is a critical indicator of heat strain.However,direct measures are often invasive,costly,and difficult to implement in the field.This study assessed the agreement between deep body temperature estimated from heart rate and that measured directly during repeated work bouts while wearing explosive ordnance disposal(EOD)protective clothing and during recovery.Methods:Eight males completed three work and recovery periods across two separate days.Work consisted of treadmill walking on a 1%incline at 2.5,4.0,or 5.5 km/h,in a random order,wearing EOD protective clothing.Ambient temperature and relative humidity were maintained at 24℃and 50%[Wet bulb globe temperature(WBGT)(20.9±1.2)℃]or 32℃and 60%[WBGT(29.0±0.2)℃]on the separate days,respectively.Heart rate and gastrointestinal temperature(TGI)were monitored continuously,and deep body temperature was also estimated from heart rate(ECTemp).Results:The overall systematic bias between TGI and ECTemp was 0.01℃with 95%limits of agreement(Lo A)of±0.64℃and a root mean square error of 0.32℃.The average error statistics among participants showed no significant differences in error between the exercise and recovery periods or the environmental conditions.At TGI levels of(37.0–37.5)℃,(37.5–38.0)℃,(38.0–38.5)℃,and>38.5℃,the systematic bias and±95%Lo A were(0.08±0.58)℃,(–0.02±0.69)℃,(–0.07±0.63)℃,and(–0.32±0.56)℃,respectively.Conclusions:The findings demonstrate acceptable validity of the ECTemp up to 38.5℃.Conducting work within an ECTemp limit of 38.4℃,in conditions similar to the present study,would protect the majority of personnel from an excessive elevation in deep body temperature(>39.0℃).

Protective Performance of Woven Fabrics against Heat Radiation

In this paper,the protective performance of woven fab-rics against heat radiation is studied from the view offabric structure.As indices reflecting the protective per-formance against heat radiation,the heat emissivity andthe transmissivity of different fabrics are measured.It ispointed out that structure changes of common textiles af-fect their transmission to heat radiation while have littleinfluence on their absorption or reflection to heat radi-ation except fabrics surfaces are aluminized.Double-layer weave is proved to be an effective fabric weave forreducing the trasmissivity.It helps increase the densityand tightness while keeps the comfort of woven fabrics atthe same time.

Modeling Thermal Protective Performance of Multilayer Fabrics for Firefighters

This paper is to report a prediction model for thermal protective performance of multilayer fabrics based on Matlab neural network toolbox. Then a back propagation (BP) neural network model is developed to predict thermal protective performance of multilayer fabrics for firefighters. The network consists of twelve input nodes, six hidden nodes, and one output node. The inputs are weight, thickness, density of warp and weft, limited oxygen index (LOI), and heat conductivity of each-layer fabric. Thermal protective performance (TPP) rating of multilayer fabrics is the output. In this paper, the data from the experiments are used as learning information for the neural network to develop a reliable prediction model. Finnally the model performance is verified, and the proposed model can be applied to predict the thermal protective performance of multilayer fabrics for firefighters.

Superabsorbent Fibers for Comfortable Disposable Medical Protective Clothing

Disposable medical protective clothing for 2019-nCoV mainly consists of stacked layers with nanopore films,polymer coated nonwoven fabrics and melt-blown nonwoven fabrics against anti-microbial and anti-liquid penetration.However,such structures lack moisture permeability and breathability leading to an uncomfortable,stuffy wearing experience.Here,we propose a novel medical protective clothing material with a superabsorbent layer to enhance moisture absorption.Poly(acrylic acid-co-acrylamide)/polyvinyl alcohol superabsorbent fibers(PAAAM/PVA fibers)were prepared via wet spinning.And the superabsorbent composite layer was stacked from PAAAM/PVA fibers,bamboo pulp fibers(BPF)and ethylene-propyl-ene side by side fibers(ESF).The novel disposable medical protective composite fabric was obtained through gluing the superabsorbent layer to the inner surface of strong antistatic polypropylene nonwoven fabric.The resultant composite fabric possesses excellent absorption and retention capacity for sweat,up to 12.3 g/g and 63.8%,and a maximum hygroscopic rate of 1.04 g/h,higher than that of the conventional material(only 0.53 g/h).The moisture permeability of the novel material reached 12,638.5 g/(m^(2) d),which was 307.6%of the conventional material.The novel material can effectively reduce the humidity inside the protective clothing and significantly improve the comfort of medical staff.

Attenuation coefficients of gamma and X-rays passing through six materials

The aim of this study was to determine the attenuation of gamma and X-rays with different energies caused by passage through different materials.To this end,different materials with a range of atomic numbers were chosen to measure gamma and X-ray attenuation coefficients and to explore the mechanisms of interaction of gamma and X-rays with matter of various kinds.It is shown that the attenuation coefficients first decrease and then increase with increase in the radiation(photon)energy.The attenuation of gamma and X-rays passing through materials with high atomic number is greater than that in materials with low atomic number.The attenuation minimum is related to the atomic number of the irradiated materials.The larger the atomic number is,the lower the energy corresponding to attenuation minimum is.Photoelectric and Compton effects are the main processes when gamma rays pass through individual materials with high and low atomic numbers,respectively.Therefore,for radiotherapy and radiation protection,different methods should be considered and selected for the use of gamma and X-rays of different energies for use in different materials.

Establishment of the key Technical Indicators of Positive Pressure Biological Protective Clothing

Objective:Trying to establish the key technical indicators related to positive pressure biological protective clothing(PPBPC),providing technical support for the establishment of PPBPC standards in the future.Method:We examined the protection standard systems established by the major standards organizations in China and other developed countries.We also analyzed the technical indicators of the gas-tight chemical protective clothing and ventilated protective clothing against particulate radioactive contamination which closely related to PPBPC.And tested the performance of a set of imported dual-purpose PPBPC to verify the fit of its technical indicators with the standards.We aimed to identify the status of China’s standards in the area of personnel protection and put forward feasible suggestions for the production of PPBPC in China.Results:Developed countries in Europe and North America have a complete system of standard protective clothing.China should also strengthen the construction of standard protective clothing,especially PPBPC.Conclusion:With the improvements in infectious disease prevention and control on a global scale,the demand for PPBPC continues to increase and consideration should be given to the establishment of standards for this.

Common damage and repair of positive pressure protective clothing for BSL-4 laboratory

Positive Pressure Protective Clothing(PPPC)is the most important personal protective equipment for BSL-4 laboratory and a primary barrier to avoid exposure to pathogenic microorganisms.However,during the process of storage,utilization,disinfection and inspection,it will be inevitable damaged in varying degrees.PPPC is expensive;therefore,effective repairs become an important procedure to prolong service life of PPPC and to ensure their protective function.This paper analyzed those common damages in PPPC during routine BSL-4 laboratory operations and provided repair plans which can be used as references for users and maintenance personnel.

Study on Compliance with Radiation Protection Rules in the Medical Imaging Department of Pr Bocar Sidy Sall Hospital of Kati (Mali)

Objective: Evaluate the level of compliance with radiation protection rules in the medical imaging department of the University Hospital Center (CHU) of Kati. Methodology: This was a cross-sectional and descriptive study carried out in the medical imaging department of Pr Bocar Sidy Sall (BSS) Hospital of Kati. A questionnaire was developed and sent to the staff of the medical imaging department. The assessment focused on the radiation protection of personnel, radiation protection measures for patients, the delimitation and signage of zoning as well as the application of radiation protection principles. Results: Twenty-one people participated in the study, 90% of whom were men. The 30 - 39 age group was predominant with 61.90%. 33.33% of the staff knew the principles of radiation protection;86% of our sample knew the basic rules of radiation protection. The majority of the staff in the imaging department (61.90%) had a perfect knowledge of protective equipment. For 76% of our workforce, the limits of the radiation doses received are regulated in Mali. 76% of those surveyed have not taken any additional training in radiation protection. The doors are closed during the X-ray examination for 76.19% of the respondents and 95% of the staff put themselves behind the sealed screen during the examination. For 81% of the respondents, the design of the premises met radiation protection standards. 62% of practitioners have a dosimeter and 80% of them wear it during their shift. For 62% of our sample, the change of the dosimeter is quarterly. The systematic request for DDR (date of last menstrual period) in women and the adaptation of the delivered dose to the patient’s morphology was only carried out by 65% of practitioners. The majority of staff (81%) did not benefit from medical surveillance, while for 55% of respondents the level of radiation protection in the establishment was average. Conclusion: This study enabled us to highlight the shortcomings in terms of radiation protection within the imaging department of the CHU Kati.

军用防护服发展现状与趋势

军用防护服在军事作战和应急救援中发挥着重要作用,因而对其特殊环境下的防护性能提出了更高的要求。从防护服的色彩、面料、结构3个方面介绍军用防护服的主要功能,其中,面料是军用防护服的核心组成部分,直接关系到防护能力和作战效能,高性能纤维材料在军用防护服中已得到广泛应用。结合研究现状,提出未来军用防护服的发展趋势,将聚焦于高性能纤维材料、智能可穿戴材料和环保材料的综合应用,进而为军用防护服设计的系统研究提供一定的参考。

国内外防电弧服开发及性能评价体系研究

文章介绍了防电弧服的分类和款式,阐述了防电弧材料及影响电弧防护性能的因素,对比分析了国内外防电弧服性能评价标准体系和测试技术。在此基础上,从功能性、舒适性和标准3个方面对防电弧服的未来发展进行了展望。

楚雄彝族服饰保护和传承的新路径思考

彝族服饰是彝族文化的一个重要组成部分,在商业经济和城市化进程的影响下,传统的彝族服饰日渐衰落。文章采用文献综述和田野调查的方法,分析楚雄彝族服饰日渐消失的成因源于时代困境、大众心理变化、城市化进程与过度商业化的冲击。据此,文章提出加强对彝族服饰的宣传及保护力度、拓展彝族传统服饰文化的传播渠道、保护当地的文化生态等一系列行之有效的策略,推动楚雄彝族民族服饰的保护与传承。