• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.1 s.160
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• pp.119-130
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• 2007

The objects of this study were to investigate responses and peculiarity during local cooling by parts of the human body and to show permissible safety limits without injurious to his health because of excessive cooling when he works hot environments. It were measured rectal temperature, skin temperature, heart rate, total body weight loss, local sweat in back and thigh, clothing microclimate and subjective sensation on 8 subjects and cooling parts were head, neck, chest, abdomen, back, waist, hip, upper arm, forearm, hand, thigh, calf and foot. According to above-mentioned the first experiment, we chose permissible safety limits by parts of the human body for one hour. In the second experiment, it was showed permissible safety limits by parts which examined their safety about health through 4 hours cooling test on 3 subjects. The results are as follows: 1. As a result of the first experiment, we chose permissible safety limits by parts, as follows, head $25^{\circ}C$, neck $20^{\circ}C$, chest $27^{\circ}C$, abdomen $25^{\circ}C$, back $20^{\circ}C$, waist $20^{\circ}C$, upper arm $20^{\circ}C$, forearm $20^{\circ}C$, hand $23^{\circ}C$, thigh $20^{\circ}C$, calf $20^{\circ}C$ and foot $23^{\circ}C$ in $37^{\circ}C$, 50%R.H. environment for 1 hour. 2. As a result of the second experiment, cooling on these safety limits temperatures except chest didn't have a bad effect on health. So it was proved that right permissible safety limits of chest was $28^{\circ}C$. From these results, it has been suggested that skin temperature didn't fall below permissible safety limits when human body was to be cool by parts.

• The Korean Journal of Community Living Science
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• v.18 no.1
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• pp.87-95
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• 2007

This study was to determine the effect of cooling parts of the limbs without harm to health. The results provide basic data for the development of clothing which could increase work efficiency and reduce body strain in hot environments. Five male adults took part in the study, conducted in a climate chamber with an ambient temperature of $37^{\circ}C$ and a relative humidity of 50%. The limbs were divided into six areas to be cooled: upper arm, forearm, thigh, calf, hand, and foot. According to preceding studies, permissible cooling safety limits of skin temperature for each part of the body for one-hour were $20^{\circ}C$ on the upper arm, forearm, thigh, and calf, and $23^{\circ}C$ on the hand and foot. For this reason, cooling the skin of each region was carried out at the above mentioned temperatures. In conclusion, cooling the hand and foot reduced perspiration, rectal temperature and heart rate. Therefore, the heat stress of workers exposed to hot environments would be reduced by decreased subjective sensations of heat and increased comfort. The effectiveness of cooling was better on the arm than on the leg.

• Journal of Environmental Health Sciences
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• v.33 no.3
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• pp.211-216
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• 2007

This study was to determine the effect of cooling part of the trunk without harm for the health. The results provide basic data for the development of clothing which could increase work efficiency and reduce body strain in hot environment. Eight males took part in the study. The experiment was conducted in a climate-chamber controlled with $37{\pm}1^{\circ}C,\;50{\pm}5%R.H$. The trunk was divided into six areas to be cooled: head, neck, chest, abdomen, the upper back, the lower back. According to preceding studies, permissible safety cooling limits of skin temperature, of each part of the trunk for four hours cooling were $25^{\circ}C$ on the head, $20^{\circ}C$ on the neck, $27^{\circ}C$ on the chest, $25^{\circ}C$ on the abdomen, $20^{\circ}C$ on the upper back, $20^{\circ}C$ on the lower back. So cooling temperatures of each region set up temperatures above mentioned. In conclusion, the head, the neck and the upper back cooling could reduce sweating amount, rectal temperature and heart rates and reduce the heat stress of workers exposing in the hot environment by decreased subjective sensations of heat and comfort. Thus, it was concluded that effectiveness of cooling among the trunk was best on the head and the neck.

• Safety and Health at Work
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• v.8 no.3
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• pp.237-245
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• 2017

Background: Solar furnaces are used worldwide to conduct experiments to demonstrate the feasibility of solar-chemical processes with the aid of concentrated sunlight, or to qualify high temperature-resistant components. In recent years, high-flux solar simulators (HFSSs) based on short-arc xenon lamps are more frequently used. The emitted spectrum is very similar to natural sunlight but with dangerous portions of ultraviolet light as well. Due to special benefits of solar simulators the increase of construction activity for HFSS can be observed worldwide. Hence, it is quite important to protect employees against serious injuries caused by ultraviolet radiation (UVR) in a range of 100 nm to 400 nm. Methods: The UV measurements were made at the German Aerospace Center (DLR), Cologne and Paul-Scherrer-Institute (PSI), Switzerland, during normal operations of the HFSS, with a high-precision UV-A/B radiometer using different experiment setups at different power levels. Thus, the measurement results represent UV emissions which are typical when operating a HFSS. Therefore, the biological effects on people exposed to UVR was investigated systematically to identify the existing hazard potential. Results: It should be noted that the permissible workplace exposure limits for UV emissions significantly exceeded after a few seconds. One critical value was strongly exceeded by a factor of 770. Conclusion: The prevention of emissions must first and foremost be carried out by structural measures. Furthermore, unambiguous protocols have to be defined and compliance must be monitored. For short-term activities in the hazard area, measures for the protection of eyes and skin must be taken.

• Applied Chemistry for Engineering
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• v.29 no.4
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• pp.413-418
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• 2018

Cypress woods treated individually with boric acid (BA4), ammonium pentaborate (APB4), or BA4/APB4 additives were examined for combustion gases. Each of the specimens was painted with a 4 wt% solution of boron compounds three times. Dried at room temperature, the combustion gas was analyzed using a cone calorimeter (ISO 5660-1). Consequently, the second maximum oxygen consumption rate of the specimen treated with boron compounds was 0.1067 to 0.1246 g/s, which was 5.3 to 18.9%, respectively lower than that of the blank specimen. The specific extinction area of specimens treated with BA4 and APB4 was also 2.0 to 19.0% lower, respectively. However, treated with BA4/APB4 showed 21.2% higher than that of the blank specimen. The maximum carbon monoxide concentration of the specimens with boron compounds was reduced by 0 to 25%. It was estimated to be 1.6 to 2.2 times higher than the permissible exposure limits by Occupational Safety and Health Administration (OSHA), indicating a fatal toxicity. The boron compounds were effective in reducing carbon monoxide, but didn't meet the OSHA limit. The boron compound inhibited the burning behavior of the cypress wood, which suppressed the second maximum oxygen consumption rate by 5.3 to 18.9% and the maximum carbon monoxide generation by 0 to 25%.