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One of the main purposes of clothing is to provide the wearer protection against undesirable environments. The properties of clothing materials have critical influences on the comfort of the wearer. Also, clothing is not just a passive cover for the skin, it interacts with and modifies the heat regulating function of the skin and has effects that are modified by the environment condition. Up to the present, most physiological studies have been on the thermal regulation of the human body without clothing. Although it is a necessary first step, more realistic and valuable information can only be obtained through studies of the interaction between clothing and the physiological aspects of the human wearer. This study reports an investigation into the combined effects of the properties of the clothing material and environment conditions on the rectal temperature of human wearers. The rectal temperature was the highest for the clothing with the lower air permeability and moisture regain during both the cooling and heating periods. In the hot environment after heating, the rectal temperature was the lowest for the clothing with the higher air permeability and moisture regain in environments of both with and without wind.
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Since the 1970s, occupational burnout has become a popular topic of research and an important concern for career counsellors. The majority of studies on burnout focussed on…
Abstract
Since the 1970s, occupational burnout has become a popular topic of research and an important concern for career counsellors. The majority of studies on burnout focussed on documenting its existence within certain occupational groups. The assumption underlying these studies is that occupational burnout is a universal phenomenon that can be best explained by the stresses characterising a particular occupation or organisation. Few studies examined burnout cross‐culturally. The present study attempted to demonstrate the importance of such a cross‐cultural perspective using a comparison between Israeli Jews and Arabs, who live in the same country but are culturally different: Arabs traditional and collectivist, Jews modern and individualistic. Interviews with representative samples of the Jewish and Arab populations in Israel show significant differences in occupational burnout and various burnout correlates. Thus, Arabs’ burnout correlated negatively with the quality of relationships with mother and father, Jews’ with superiors and co‐workers. Arabs were significantly less likely than Jews to talk about a work‐related problem or approach a counsellor. These findings have both theoretical and practical implications for career counselling.
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I‐V characteristics of GaAs n‐i‐n structures are calculated by considering impact ionization of carriers. Impact ionization at reverse‐biased n‐i junction becomes a cause of steep…
Abstract
I‐V characteristics of GaAs n‐i‐n structures are calculated by considering impact ionization of carriers. Impact ionization at reverse‐biased n‐i junction becomes a cause of steep current rise when an acceptor density in the i‐layer is high. It is shown that an optimum acceptor density exists to keep a good isolation. Photoconduction transients of GaAs n‐i‐n structures are also simulated, and are shown to be strongly affected by existence of n‐i junctions.
Yuqi Tang, Zhantong Mao, Anni Li and Lina Zhai
The purpose of this paper is to study the heat transfer effect of copper sensor and skin simulant on skin.
Abstract
Purpose
The purpose of this paper is to study the heat transfer effect of copper sensor and skin simulant on skin.
Design/methodology/approach
For the sensor, the physical and mathematical models of the thermal sensors were used to obtain the definite conditions in the heat transfer process of the sensor, and the heat transfer models of the two sensors were developed and solved respectively by using ANSYS WORKBENCH 19.0 software. The simulation results were compared with the experimental test results. For the skin, the numerical model of the skin model was developed and calculated. Finally, the heat transfer simulation performance of the two sensors was analyzed.
Findings
It is concluded that the copper sensor is more stable than the skin simulant, but the material and structure of the skin simulant is more suitable for skin simulation. The skin simulant better simulates the skin heat transfer. For all the factors in the model, the thermal properties of the material and the heat flux level are the key factors. The convective heat transfer coefficient, radiation heat transfer rate and the initial temperature have little influence on the results, which can be ignored.
Research limitations/implications
The results show that there are still some differences between the experimental and numerical simulation values of the skin simulant. In the future, the thermal parameters of skin simulant and the influence of the thermocouple adhesion should be further examined during the calibration process.
Practical implications
The results suggest that the skin simulant needs to be further calibrated, especially for the thermal properties. The copper sensor on the flame manikin can be replaced by the skin simulant with higher accuracy, which will be helpful to improve the accuracy of performance evaluation of thermal protective clothing.
Social implications
The application of computational fluid dynamics (CFD) technology can help to analyze the heat transfer simulation mechanism of thermal sensor, explore the influence of thermal performance of thermal sensor on skin simulation, provide basis for the development of thermal sensor and improve the application system of thermal sensor. Based on the current research status, this paper studies the internal heat transfer of the sensor through the numerical modeling of the copper sensor and skin simulant, so as to analyze the effect of the sensor simulating skin and the reasons for the difference.
Originality/value
In this paper, the sensor itself is numerically modeled and the heat transfer inside the sensor is studied.
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Ali Mohamadi Sani and Mahya Sheikhzadeh
This paper aims to provide information on the different methods of aflatoxin (AFT) degradation in rice.
Abstract
Purpose
This paper aims to provide information on the different methods of aflatoxin (AFT) degradation in rice.
Design/methodology/approach
Crops that are affected by AFT contamination include cereals, oilseeds, spices and tree nuts. AFT in rice may harm health to great extent, and if not properly determined, may cause death. The production and occurrence of mycotoxins differ depending on the geographic and climatic and environmental conditions; however, these toxicants can never be removed completely from the food supply.
Findings
Mycotoxins are commonly present in cereal grains such as rice and are not completely destroyed during their cooking and processing.
Originality/value
No review on detoxification of AFT has been found in rice.
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Yelin Ko, Sora Shin, Yong Seok Choi, Byung-Hee Hong, Sang-Yoon Park and Joo-Young Lee
The purpose of the study was to explore heat-accumulative and thermal-conductive characteristics of copper-graphene composite film (Cu-G film) while applying it to a human-skin…
Abstract
Purpose
The purpose of the study was to explore heat-accumulative and thermal-conductive characteristics of copper-graphene composite film (Cu-G film) while applying it to a human-skin analogue.
Design/methodology/approach
In the preliminary experiment, the authors evaluated the thermal conductive characteristics of the Cu-G film in three covered conditions (no film, copper film, and Cu-G film conditions). For the first factorial experiment, the heat-accumulative properties over heated pig skin were compared at air temperatures of 10, 25 and 35°C. For the second factorial experiment, 105 trials were conducted on pig skin by combining air temperatures, trapped air volumes, and numbers of film layers.
Findings
The results from the preliminary experiment showed that the Cu-G film distributed the surface heat to the outside of the Cu-G film, which resulted in even distribution of heat inside and outside the Cu-G film, whereas the copper film accumulated heat inside the copper film. The human-skin analogue of pig skin, however, showed the opposite tendency from that of the plastic. The pig-skin temperatures beneath the Cu-G film were higher than those beneath the copper film, and those differences were remarkable at the air temperature of 10°C. The accumulative heat was affected by the trapped air volume, fit to the skin, and number of Cu-G film layers.
Originality/value
In conclusion, the Cu-G film more effectively accumulated heat on the human-skin analogue than copper film, and those effects were more marked in cold environments than in mild or hot environments.
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Meng Deng, Yunyi Wang and Peijing Li
The purpose of this paper is to provide the details of developments to research works in the distribution characteristics of the air gaps within firefighters’ clothing and…
Abstract
Purpose
The purpose of this paper is to provide the details of developments to research works in the distribution characteristics of the air gaps within firefighters’ clothing and research methods to evaluate the effect of air gaps on the thermal protective performance of firefighters’ clothing.
Design/methodology/approach
In this paper, the distribution of air gaps within firefighters’ clothing was first analyzed, and the air gaps characteristics were summarized as thickness, location, heterogeneity, orientation and dynamics. Then, the evaluation of the air gap on the thermal protective performance of fighters’ clothing was reviewed for both experimental and numerical studies.
Findings
The air gaps within clothing layers and between clothing and skin play an important role in determining the thermal protective performance of firefighters’ protective clothing. It is obvious that research works on the effects of actual air gaps entrapped in firefighters’ clothing on thermal protection are comparatively few in number, primarily focusing on static and uniform air gaps at the fabric level. Further studies should be conducted to define the characteristic of air gap, deepen the understand of mechanism of heat transfer and numerically simulate the 3D dynamic heat transfer in clothing to improve the evaluation of thermal protective performance provided by the firefighters’ clothing.
Practical implications
Air gaps within thermal protective clothing play a crucial role in the protective performance of clothing and provide an efficient way to provide fire-fighting occupational safety. To accurately characterize the distribution of air gaps in firefighters’ clothing under high heat exposure, the paper will provide guidelines for clothing engineers to design clothing for fighters and optimize the clothing performance.
Originality/value
This paper is offered as a concise reference for researchers’ further research in the area of the effect of air gaps within firefighters’ clothing under thermal exposure.
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Shuang Huang, Xin Wu and Peixing Li
In the textile industry, liquid ammonia treatment is an important way to modify the structure of natural fibers. The purpose of this paper is to reveal the diffusion behaviors of…
Abstract
Purpose
In the textile industry, liquid ammonia treatment is an important way to modify the structure of natural fibers. The purpose of this paper is to reveal the diffusion behaviors of liquid ammonia in cellulose.
Design/methodology/approach
To analysis the diffusion behaviors of liquid ammonia in cellulose, the cellulose model and the system of ammonia and cellulose are built. Infrared spectrum is carried out to test the model of cellulose, which is found to agree with experiment. Diffusion coefficients, free volume and hydrogen bonds are discussed to explain diffusion behaviors.
Findings
The results demonstrate that diffusion coefficients and free volume of systems rise with increasing temperature. The diffusion coefficients of ammonia are larger than those of water, a result in agreement with free volume. To understand the mechanism of diffusion, the numbers of hydrogen bonds are tracked. It is found that without ammonia, intrachain hydrogen bonds decrease with the increase of temperature, which indicate that the structural stability of cellulose is deteriorated. And the increased interchain hydrogen bonds show that swelling properties of cellulose become better with the increase of temperature. After ammonia treatment, the numbers of intrachain hydrogen bonds remain stable, indicating that the structure stability of cellulose chain is maintained. But, there is a substantial rupture of interchain hydrogen bonds, ammonia molecule destroys the hydrogen bond network between the original cellulose molecular chains, which intensifies the activity of cellulose molecular chains and enlarges the distance between cellulose molecular chains, showing good swelling properties.
Originality/value
The research findings give a detailed information about the diffusion behaviors of liquid ammonia in cellulose, which provide the theoretical evidence for liquid ammonia treatment.
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Ping Wang, Yixia Hu, Qiao Li and Hanqin Yang
Journalism students, a special user group with the dual perspective of both social media general users and online journalists, and their trust in rumours is a valued but…
Abstract
Purpose
Journalism students, a special user group with the dual perspective of both social media general users and online journalists, and their trust in rumours is a valued but understudied topic in relation to preparing rational information users and professionals for rumour control. To reveal these trust mechanisms, this paper aims to identify salient psychological and behavioural factors related to journalism students’ different levels of trust.
Design/methodology/approach
Using structural equation modelling to analyse the survey data of 234 journalism students, this paper tested a theoretical model that considers self-efficacy and the expressive and consumptive use of social media rumours as the antecedents and consequences of trust belief and trust action, respectively.
Findings
Self-efficacy has a positive effect on trust belief but a negative effect on trust action. Trust belief positively affects expressive use of rumours, whereas trust action negatively affects consumptive use.
Practical implications
This study contributes to the cultivation of future online news gatekeepers.
Originality/value
This paper distinguishes journalism students’ trust mechanisms from those of general users and online journalists. The integration of dual process theories provides insights into trust-building processes related to rumours and advances the understanding of the anchoring and adjustment effects of self-efficacy on trust.
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Markus Weder, René M. Rossi, Cyril Chaigneau and Brice Tillmann
The purpose of this investigation is to measure seven different underwears on a sweating torso with differing relative air humidity (30, 50, 80 and 95 per cent RH) and at a fixed…
Abstract
Purpose
The purpose of this investigation is to measure seven different underwears on a sweating torso with differing relative air humidity (30, 50, 80 and 95 per cent RH) and at a fixed ambient temperature of 30°C to determine the influence of the water vapour partial pressure of the environment on the moisture transport properties of various materials.
Design/methodology/approach
All measurements in this investigation were accomplished with the authors' sweating torso which simulates the thermal‐ and humidity release of the human body. Four different sweating rates (50, 75, 100 and 150 g/h*torso) were selected for this investigation.
Findings
It was established that the partial pressure difference did not correlate directly with the evaporative cooling. In general, higher evaporation rates were observed in the dry climate conditions. However, with low‐sweat rates, the highest relative humidity (95 per cent) generally resulted in greater evaporative cooling than the lowest surrounding humidity conditions (30 per cent). In this investigation, a blended fabric made of PES/Vinal exhibited the most efficient evaporative cooling for all the sweat rates, as well as for the four relative humidity conditions chosen.
Research limitations/implications
All received results are based on a surrounding temperature of 30°C (summer climate), for other temperatures the results may be different.
Originality/value
The investigation shows that both the relative humidity and the sweat rate have a major influence on the heat loss.
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