Layers Of Cloth Research Articles

Application of A New Firefighter Protective Clothing Material in Fire Rescue

Firefighters are usually exposed to high temperatures, smoke and other hazards from the environment when carrying out fire fighting and rescue. Fire fighting clothes are special protective clothes used to protect firefighters from high temperature and fire damage. PPS fabrics can meet the basic requirements of fire service coatings. According to the standard requirements of a pair of firefighters’ chemical protective clothing, this topic further coats the surface of PPS fabric to achieve a certain chemical penetration resistance, and does basic research on the application of PPS fibers in the outer layer of chemical protective clothing. It can be used to make exterior material of Fire Fighting Protective clothing. Fabric density affects the warp and weft tear properties, but due to the limited fabric density in this design, the density does not affect much. In addition, it has been found that reducing the latitude and longitude density difference can increase the latitudinal tear strength value. The possibility of multi-stage airbag cushioning type pressure-proof protective clothing captured in actual fire-fighting and rescue work is analyzed, which provides a certain guarantee for the safety of fire-fighters during fire-fighting and rescue operations.

Thermal Conductivity Simulation of High Temperature Overalls Materials

When workers work in high temperature environments, they need to wear high temperature work clothing to avoid burns. The garment is often composed of three layers of fabric material, which are referred to as layers I, II, and III from the outside to the inside, and there is a gap between the layer III and the skin. We refer to this void as the IV layer. In order to make the design of special clothing more efficient, reduce research and development costs, and shorten the development cycle, this paper uses mathematical models to determine the temperature changes outside the skin of the dummy. We assume that the body temperature of a dummy wearing a high temperature workwear can be controlled at 37 °C. We have established a set of thermal differential equations as a heat transfer model for the four layers of high temperature work clothing. First, we consider three heat transfer modes of heat conduction, heat radiation and heat convection, and analyze the heat conduction form of each layer to obtain a one-dimensional unsteady heat transfer model. Then, the numerical solution of all partial differential equations is obtained by the finite difference method of Crank-Nicolson format, and the temperature distribution outside the skin of the dummy is obtained. Finally, this paper gives a proposal for the design work of four-layer high temperature work clothing in combination with the actual situation.

Metabolic rate and muscle activation level when wearing state-of-the-art cold-weather protective clothing during level and inclined walking

Use of cold-weather personal protective clothing (PPC) in cold climates is essential but can add metabolic cost to the wearer. This study measured the effect of wearing state-of-the-art PPC and personal protective equipment (PPE), with the possible effect of clothing layers and fit, on physiological responses including metabolic rate (MR) and muscle activation level. 19 male participants (80.2 ± 5.9 kg, 181.5 ± 5.1 cm) wore five different clothing ensembles during level (0°) and inclined (6°) walking. Compared to a base layer ensemble (388.7 ± 42.7 W/737.8 ± 57.9 W), wearing a 3-layer PPC ensemble (421.5 ± 44.7 W/811.7 ± 69.2 W) significantly increased MR, and adding PPE (458.3 ± 59.8 W/864.5 ± 71.2 W) further increased MR during level/inclined walking. Independent of the extra weight, adding a middle layer between base layer and outer clothing significantly increased MR during inclined walking only, and no effect of oversized outer clothing was measured.

Everyday weather-ways: Negotiating the temporalities of home and work in Melbourne, Australia

Although a number of researchers have responded to calls to better understand human experiences of weather in the context of a changing climate, there remain few studies that analyse the role of weather in everyday urban life, where mediating technologies such as air-conditioners and tumble dryers are widespread. To address that gap, this paper advances a concept of ‘weather-ways’, in which cultural understandings of weather are conceived as dynamic, unfolding and interactive. Empirically, we examine how weather is part of the daily practices of 20 Melbourne (Australia) participants using interviews conducted across four seasons in 2010–11. Findings show a particular distinction between work and home weather-ways. Office work practices provided a highly structured weekly temporal framework around which other practices were organised. Regardless of the weather, work practices continued undisrupted, particularly in air-conditioned buildings. Away from work, where participants had more freedom to engage with and respond to the weather, they demonstrated a willingness to remain weather-connected, despite having access to technologies. Participants modified their practices in accordance with weather and its variations, through both simple adjustments, such as modifying clothing layers, and broader responses including the temporal and spatial adjustments of leisure and laundering activities that took advantage of ‘good’ weather or avoided less favourable conditions. Vernacular adjustment strategies that may assist in adjusting to future climate changes are in tension with the structural and collective frameworks of most indoor workplaces.

ДЕФОРМАЦИОННЫЙ РЕЛЬЕФ И ДЕСТРУКЦИЯ ПОВЕРХНОСТИ КАК ПОКАЗАТЕЛИ УСТАЛОСТНОЙ ПОВРЕЖДЕННОСТИ ПЛАКИРОВАННОГО АЛЮМИНИЕВОГО СПЛАВА

The article presents the results of the study of changes in the state of the structural alloy D16AT surface with the operating time at various stress levels. The state of the surface of the material was monitored by an interference nanoprofiler. The main feature of the D16AT alloy is that to protect against corrosion, the material is coated on both sides with a thin layer of clad, the thickness of which is about 5 % of the sheet total thickness. During loading, the deformation of the cladding layer and the base material due to the existing difference in the yield strength values differs significantly. Such a composition of inextricably bound materials will contribute to the intensification of plastic deformation of the surface layer. During cyclic loading, areas of plastically deformed material are formed and developed on the surface of a clad aluminum alloy with a special representation of the surface relief caused by dislocation mechanisms (steps and slip bands, extrusion, intrusion etc.). Quantitative indicators of deformation relief (DR) are the area and perimeter of plastic-deformed areas, their fractal characteristics and plastic deformation of the surface. These parameters can act as indicators of the alloy fatigue damage, but it is hard to identify the boundary state that is the fatigue crack initiation. Such a diagnostic parameter is the destruction of the clad layer to determine in order are used basic indicators of DR. Destruction (increase in the volume of the clad layer) is physically objective that is associated with an increase in surface area during the formation and extended of DR. Destruction can be considered as the main factor in the fatal destruction of clad aluminum alloys. It is shown that when saturated with a deformation relief, approximately 25 ... 30 % of the total surface area of the destruction of the clad layer increases abruptly due to the change in the nature of the plastic deformation of the surface that is an increase in the growth of its plane at high saturation values. This saturation value can be used as a diagnostic indicator of the initial fatigue cracks initiation.

Engineering of a backpack ventilation technology for cycling using CFD analysis

Thermoregulation of an athlete during physical activities plays an important role especially in endurance sports such as cycling. Depending on the kind and intensity level of the activity thermoregulation can affect performance and/or thermal comfort. During cycling, especially within the MTB categories, athletes often wear a backpack. The overall goal of the study was to engineer a new backpack ventilation technology utilizing the relative headwind generated during cycling for convective heat transfer between backpack and first clothing layer. Exploration and evaluation of new rear panel designs were done applying a CFD analysis. CFD Analyses were done at AirShaper TM using a steady-state RANS (Reynols Averaged Navier Stokes) method with k-omega SST turbulence model. The CFD analysis of the newly developed rear panel designs exhibit the potential to influence the convective heat transfer especially around the spine region in a positive way during cycling.

The effect of military clothing on gunshot wound patterns in a cadaveric animal limb model

The majority of injuries in survivors of gunshot wounds (GSW) are typically to the extremities. Novel wound ballistic research is encouraged to try and capture corporate knowledge on the management of these injuries gained during recent conflicts and understand the wounding patterns seen. With recent work examining the effect of UK military clothing on extremity GSW patterns in a synthetic model, a model with greater biofidelity is needed for ballistic testing. The aim of this study was to assess the effect of UK military clothing on GSW patterns within a cadaveric animal limb model using two types of ammunition commonly used in recent conflicts—7.62 × 39 mm and 5.45 × 39 mm. In total, 24 fallow deer hind limbs were shot, 12 by 7.62 mm projectiles and the remaining 12 shot by 5.45 mm projectiles, further divided into four with no clothing layers (Cnil), four with a single clothing layer (Cmin) and four with maximum clothing layers (Cmax) as worn on active duty by UK military personnel. Limbs were analysed after ballistic impact using contrast CT scanning to obtain measurements of permanent cavity damage, and results were compared using analysis of variance (ANOVA). Results showed significantly different damage measurements within limbs with Cmax for both ammunition types compared with the other clothing states. This may result in GSWs that require more extensive surgical management, and invites further study.

Analytical clothing model for sensible heat transfer considering spatial heterogeneity

Existing clothing models assume spatial homogeneity of the enclosed air layer between skin and fabric, which contradicts real-life scenarios. Furthermore, depending on the thickness of enclosed air layer and the temperature difference between skin and fabric, natural convection may occur but it is often neglected in the theoretical models. In this study, we have developed a theoretical model that considers the spatial heterogeneity of enclosed air layer and natural convection. It computes the sensible heat transfer (conduction, radiation and natural convection) in the heterogeneous enclosed and boundary air layers. The heat transfer in the clothing layer is calculated based on the thermal resistance of the fabric.The model presented in this paper is systematically validated for natural convection and spatial heterogeneity using a thermal cylinder and a thermal manikin with increasing level of spatial complexity. The validation of the model was performed for a wide range of temperatures (−10 °C to 26 °C), enclosed air layer thicknesses (homogeneous and heterogeneous), and ambient air speeds (0.2 m/s, 1 m/s) and demonstrated a good agreement between predicted and measured heat flux with an average error of 3.7% and 9.3% for homogeneous and heterogeneous enclosed air layers, respectively.

Implicit untangling

We propose a robust method for untangling an arbitrary number of cloth layers, possibly exhibiting deep interpenetrations, to a collision-free state, ready for animation. Our method relies on an intermediate, implicit representation to solve the problem: the user selects a few garments stored in a library together with their implicit approximations, and places them over a mannequin while specifying the desired order between layers. The intersecting implicit surfaces are then combined using a new family of N-ary composition operators, specially designed for untangling layers. Garment meshes are finally projected to the deformed implicit surfaces in linear time, while best preserving triangles and avoiding loss of details. Each of the untangling operators computes the target surface for a given garment in a single step, while accounting for the order between cloth layers and their individual thicknesses. As a group, they guarantee an intersection-free output configuration. Moreover, a weight can be associated with each layer to tune their relative influence during untangling, such as leather being less deformed than cloth. Results for each layer then reflect the combined effect of the other layers, enabling us to output a plausible configuration in contact regions. As our results show, our method can be used to generate plausible, new static shapes of garments when underwear has been added, as well as collision-free configurations enabling a user to safely launch animations of arbitrarily complex layered clothing.

The Reliability of Noninvasive Blood Pressure Measurement Through Layers of Autumn/Winter Clothing: A Prospective Study

In recent years a number of publications have appeared describing noninvasive blood pressure (NIBP) measurement with 1 layer of light cloth between the patient's skin and the NIBP cuff. In this study we investigated the reliability of NIBP measurements performed through 2 and 3 layers of autumn/winter clothing in 2 research groups: healthy volunteers and patients. Oscillometric NIBP measurements were made in a random order: 1) on the exposed arm; 2) on the arm covered by a standardized cotton and polar fabric test sleeve; and 3) with the arm covered by a cotton-polar fabric and down jacket test sleeve. The time taken for measurement was also recorded. We performed measurement in 101 volunteers and 50 patients and found no clinically or statistically significant differences in NIBP. Mean±SD values in the volunteer group were 1) 130/80±14/8 mm Hg; 2) 130/81±15/8 mm Hg; and 3) 128/81±14/8 mm Hg. In the patient group the values were 1) 140/82±34/15 mm Hg; 2) 140/84±33/15 mm Hg; and 3) 137/84±32/15 mm Hg. Measuring over a sleeved arm extended the time of measurement by an average of 3.5 s in comparison with bare arm measurement. Our findings confirm that it is possible to perform reliable NIBP measurements over 2 and 3 layers of autumn/winter clothing. Measuring NIBP with a clothed arm does not show clinical or statistically significant differences in comparison with measurements performed on the bare arm.

Determination for Thickness of the Multilayer Thermal Insulation Clothing Based on the Inverse Problems

In this paper, the optimal thickness of multilayer special clothing material under the high temperature operation based on the inverse problems is studied. We analyze the parameters of the thickness of thermal insulation clothing material and the surface temperature of the dummy. Using the least-squares fitting, the function with the distribution of the dummy surface temperature is established. Then the heat transfer model and optimization model to obtain the optimal thickness of different clothing layers are built, respectively. Taking the true data as an example, we give the application of thermal insulation clothing in fire area, and the results show that the models are feasible.

Protective Role of Lycopene on Hormonal Profile and Posttesticular Functions of Male Rat Exposed to Sublethal Doses of Cyermethrin

Aim: The aim of the study is to evaluate the Protective role of Lycopene on hormonal profile and posttesticular functions of male rats exposed to sublethal doses of Cypermethrin.
 Study Design: The study was a completely randomized design employing relevant statistical tools for analysis and interpretation.
 Place and Duration of Study: The study was carried out in the Reproductive Physiology and Genetics Research Laboratory of the Department of Applied and Environmental Biology, Rivers State University, Rivers State. The experiment lasted for 35 days.
 Methodology: For the sperm morphology assay, sperm reserves and hormonal profiling, semen samples were drawn from the caudal epididymis with a syringe and placed on a clean glass slide. A drop of freshly prepared eosin-Y was added to make a thin smear and examined under the microscope for morphological abnormalities. A portion of the testis and epididymidis was homogenized separately with sharp pointed scissors in normal (physiological) saline. The suspension was mixed and strained through a double layer of sterile cheese cloth into graduated test tubes. All the samples were covered and stored for 24 hours at 40C. A dilution was made for counting in Neubauer haemocytometer. The hormonal concentration was determined using the Randox Monza Laboratories assay kit from Co-Atrim, United Kingdom. 
 Results: Results of oral administration of Cypermethrin and co-administration of lycopene in rats showed Group G co-administered pure Lycopene had the lowest sperm head abnormalities of 3.5%, group B administered Cypermethrin only had the highest head abnormalities of 44.7%. Similarly, Group G, co-administered pure Lycopene had the lowest percentage of tail abnormalities of 10.1% while Group B had the highest percentage of sperm tail abnormalities of 32.4%. There was a was significant (p<0.001) decrease in concentration of all androgens considered in group B administered Cypermethrin only.
 Conclusion: Exposure to Cypermethrin only as in group B disrupted the production of all androgens considered, increased the percentage of abnormal spermatozoa, reduced sperm motility, viability and sperm reserves. However, results recorded from the co-administration of Solanum lycopersicum and pure lycopene, in groups C-G indicate the protective role of this potent antioxidant on spermatogenesis and hormonal profile.

A Meta-Analysis on the Advancement on the thermodynamic properties of clothing in extreme cold environments

When two systems with different energies are in contact, the heat from the higher energy system will move into the lower energy system and the two will reach equilibrium. Humans in extreme cold environments will perish if they do not keep appropriate heat contained within their system and thus it is the object of much historic research to maintain heat within a system for as long as possible. Research and development of cold weather clothing focuses on a range of methods regulating heat flow between clothing layers. Modern research focuses on air gaps between layers of clothing, development of new conventional insulating textiles and contemporary solutions such as the use of Phases Change [1]. The purpose of this paper is to conglomerate all of the current research into one meta-analysis highlighting the gaps in the research and potential areas in need of further study, and to propose a new article of cold weather apparel utilizing the most effective advancements from the papers collected in this study. It was found that each component of cold climate clothing affects an aspect of thermal resistivity. Thickness affects the windchill resistance, the specific heat increases thermal resistance of the fabric, while humidity increases thermal conductivity, air gaps reduce it and the rigidity affects all of these factors. Our findings suggest if the air gaps are above 8 mm, natural convection currents can occur which increase the thermal and moisture transfer between clothing layers. By analysing all of these factors, a new prototype garment was able to be proposed.
 Keywords: Cold environment; clothing; thermoregulation.

An investigation into the ease of ice removal properties of fabrics used for the outer layer of firefighter clothing

The ease of ice removal (EIR) property indicates how easy it will be to remove ice from materials. In this study, an EIR coating was built on to the outer layer of firefighter clothing using polyurethane-2540, Teflon emulsion, nano-silica powder, copper powder and fluorine-containing water and oil-repellent-581 using a knife coating method. This coating adds an EIR function to the fabrics. The properties of the samples prepared in this paper were investigated using field emission scanning electron microscopy, a video optical contact angle measuring instrument (OCA15), an impedance analyzer (KEYSIGHT E4991B) and an EIR property tester. At the same time, the thermal protective performance (TPP) of the samples, before and after coating treatment, was studied using a TPP tester. The results show that the EIR coating can significantly increase the EIR property of the fabrics used for the outer layer of firefighter clothing. Mechanical forces between the material and ice have obvious influence on the freezing adhesive strength. Materials with lower permittivity have lower freezing adhesive strength. The EIR coating described in this paper can increase the TPP of the fabrics.

Study on the Effectiveness Evaluation of Personal Protective Equipment for Health Care Staff Trained with Graphical Interpretation and Operation

Introduction:Proper use of personal protective equipment (PPE) is essential when facing emerging infectious diseases. Proper training methods can promote the use of the PPE correctly.Aim:To explore the effect of the training method of sequential operation training on medical staff to master PPE penetration and removal skills, and to study the memory attenuation after training.Methods:Fifteen medical staff with no experience of PPE operation in a hospital were trained to wear PPE in accordance with WHO standards by illustration and sequential operation method. The training included 30 minutes of theoretical teaching and 60 minutes of practical exercises. At the end of the training and 1 week after the training, the training objects were evaluated for PPE operation. A 2.5 x 2.5 cm fluorescent agent was applied on 6 parts, such as hands, chest, abdomen, and knees, to simulate contamination. After taking the PPE off, the parts of the whole body and the inner layer of clothing that were fluorescently contaminated were recorded. The whole operation process was recorded by video to evaluate whether the operation was correct. The error rates of two operations and the contamination position and frequency were compared.Results:The error rate of the operating PPE after training was 18.6%, rising to 31.9% after 1 week (Z=16.0, P<0.05). After the training, the average number of contaminated PPE removal was 1.96±1.56, which rose to 2.96±2.03 one month later. The difference was statistically significant (Z=8.92, P<0.05). The main vulnerable sites are the wrist, chest, abdomen, and left calf.Discussion:Illustrative sequential operation training is an important means to improve the way for medical staff to wear PPE, but it must be completed more than once to ensure that medical staff can firmly master the skills of wearing and removing PPE.

Microstructures and properties of glass fiber reinforced PTFE composite substrates with laminated construction

Three kinds of composite substrates have been fabricated by stacking layers of glass fiber cloth (GFC) or glass fiber mat (GFM) impregnated with polytetrafluoroethylene (PTFE). The difference of the three kinds of substrates is the layered structures, composed of simplex GFC or GFM, or GFC and GFM alternately. The effects of glass fiber types and laminated constructions on the physical properties of composite substrates, such as dielectric constant (εr), dielectric loss (tgδ), water absorption, coefficient of thermal expansion (CTE) and microstructures were studied. The PTFE/GFM composites show similar performances with PTFE/GFC composites. The results demonstrate that the dielectric constant (GFM up to 2.23, GFC up to 2.24) and dielectric loss (GFM up to 0.0016, GFC up to 0.0018) are increased with an increase of the number of layers, on the contrary, the temperature coefficient of dielectric constant (τε) of composites has a decreasing tendency (GFM of −121 ppm °C, GFC of −114 ppm °C). At the same time, the water absorption of composites is decreased with an increase of the number of layers, which is almost twice that of other literatures (GFM of 0.019% and GFC of 0.005%). In consideration of low CTEx and CTEy of PTFE/GFC composites and low CTEz of PTFE/GFM composites, composite substrates with PTFE and alternate GFC and GFM were prepared, exhibiting relatively low CTE of 28.64, 30.52, 223.7 ppm C−1 at X, Y, Z directions, which is obviously superior to other substrates of the same type.

Preparation and catalytic activities of CuFe2O4 nanoparticles assembled with graphene oxide for RDX thermal decomposition

A graphene oxide-based nano-metal composite oxide CuFe2O4/GO was successfully prepared by a versatile self-assembly approach. Structure and morphological characterization of CuFe2O4/GO nanocomposite were studied in detail by a series of characterization techniques including XRD, FT-IR, XPS, BET, SEM, and TEM. The results revealed that the self-assembly process did not destroy the composition and morphology of the spinel-structured CuFe2O4 particle, and the transparent GO sheets with wrinkled and rough texture are tightly coated on the surface of CuFe2O4 nanoparticles like a layer of thin gauze clothing. The particle size of CuFe2O4 is about 200 nm. Catalytic activity of as-prepared CuFe2O4/GO nanocomposite on the thermal decomposition of cyclotrimethylene trinitramine (RDX) was investigated via differential scanning calorimetry (DSC). The experimental results show that the CuFe2O4/GO nanocomposite has much higher catalytic activity than single CuFe2O4 nanoparticles and GO. Thermal decomposition temperature and apparent activation energy of RDX were reduced from 241.27 to 220.34 °C and from 172.6 to 142.56 kJ mol−1, respectively. The improved performance could be attributed to the “positive synergistic effect” between CuFe2O4 nanoparticles and GO.

Skin permeation of oxides of nitrogen and sulfur from short-term exposure scenarios relevant to hazardous material incidents

Permeation of oxides of nitrogen and sulfur gases through skin and the consequences of dermal exposure are still poorly understood. We measured the penetration profile of three common industrial gases through skin, for short-term exposures relevant to HAZMAT scenarios. Time variations of gas concentration, clothing effects, temperature and humidity on epidermal absorption and penetration were assessed. Fabric off-gassing profiles were also investigated. The results show oxides of nitrogen (NO and NO2) at airborne concentrations up to lethal inhalation levels (e.g. 3000 ppm) have little skin penetration ability. Skin absorption and reservoir effects were noted. Skin exposed to SO2 (3000 ppm/30 min) shows negligible skin absorption or penetration. Fabric on skin marginally increased SO2 absorption and subsequent ventilation did not reduce the absorbed fraction. Increased temperature and humidity had limited additional effect on skin penetration. Importantly, clothing demonstrated sink properties, especially for SO2. Short-term skin exposure relevant to accidents will not significantly contribute to body burden. The greatest concern will likely be off-gassing of chemical-laden fabric for asthma suffers. The risk-based management approach is to avoid potential secondary inhalation from fabric off-gassing by removal of outer layer of bulky clothing. Decontamination and moving into an area of enhanced ventilation may also be advised.

Electrical heating properties of various electro-circuit patterns coated on cotton fabric using graphene/polymer composites

To investigate the electrical heating performance of two types of electro-circuit patterns, stripe-pattern (SP) and horseshoe-pattern (HP) types were designed by using graphene/poly(vinylidene fluoride- co-hexafluoropropylene) composites to fabricate electrical heating textiles for the inner layers of clothing and gloves to maintain body temperature. To confirm the electrical properties of the pattern shape and area of the coated circuit, the surface resistivity of SP and HP types was measured with various sample lengths, namely 100, 75, and 50 mm, respectively. The surface resistivity of each sample tends to increase linearly with the increasing size of the coated area. In addition, the surface resistivity of the HP is found to be higher than that of the SP. It could be confirmed that the surface resistivity increases as the curvature increases. For the electrical heating properties of the HP, a white-zone and a red-zone appeared clearly, and locally excess heat appeared at the white-zone; the resistive heat can be explained by the collision of the free electrons in the curved shape of the HP area. In order to confirm the applicability of the fabric heating elements, HP100/cotton, HP75/cotton, and HP50/cotton were fabricated by applying the HP to cotton fabric. The difference of surface temperatures at two points of each line of HP100/cotton, HP75/cotton, and HP50/cotton were about 6.0 ± 2.4℃, 6.8 ± 4.5℃, and 3.5 ± 1.7℃, respectively. It has been confirmed that the heating performance is improved, due to the collision of electrons in the curved region with decreasing HP100/cotton to HP50/cotton ratio, and the white-zone is also increased.

A textile with thermostat threads

Most people deal with temperature changes in their surroundings with a sartorial strategy: for example, short sleeves for a balmy day outside and a sweater for the air-conditioned office. A new smart fabric could help regulate body heat and eliminate the need for multiple layers of clothing. The textile, knit from carbon nanotube–coated triacetate-cellulose fibers, cools wearers down or warms them up depending on how hot and sweaty their skin is. Two effects give the fabric its thermostat-like properties, says YuHuang Wang, who, along with Min Ouyang, led the team at the University of Maryland, College Park, that developed the textile. First, the carbon nanotubes act like a metal, Wang explains, effectively transforming the fibers into tiny antennas. Depending on the spacing between the fibers, these antennas interact differently with infrared radiation emitted from a person’s body. This IR radiation accounts for more than 40% of the heat exchanged between