Sora Shin, Hae-Hyun Choi, Yung Bin Kim, Byung-Hee Hong and Joo-Young Lee
The purpose of this paper is to evaluate the effects of intermittent and continuous heating protocols using graphene-heated clothing and identify more effective body region for…
Abstract
Purpose
The purpose of this paper is to evaluate the effects of intermittent and continuous heating protocols using graphene-heated clothing and identify more effective body region for heating in a cold environment.
Design/methodology/approach
Eight males participated in five experimental conditions at an air temperature of 0.6°C with 40 percent relative humidity: no heating, continuous heating the chest, continuous heating the back, intermittent heating the chest, and intermittent heating the back.
Findings
The results showed that the electric power consumption of the intermittent heating protocol (2.49 W) was conserved by 71 percent compared to the continuous protocol (8.58 W). Rectal temperature, cardiovascular and respiratory responses showed no significant differences among the four heating conditions, while heating the back showed more beneficial effects on skin temperatures than heating the chest.
Originality/value
First of all, this study was the first report to evaluate cold protective clothing with graphene heaters. Second, the authors provided effective intermittent heating protocols in terms of reducing power consumption, which was able to be evaluated with the characteristics of fast-responsive graphene heaters. Third, an intermittent heating protocol on the back was recommended to keep a balance between saving electric power and minimizing thermal discomfort in cold environments.
Details
Keywords
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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Hong Chen, Byung Hee Lee and Asylgul Alymkulova
The purpose of this study is to investigate gender gaps in opportunity-driven entrepreneurship and illuminate the underlying mechanism of why women are less likely to create…
Abstract
Purpose
The purpose of this study is to investigate gender gaps in opportunity-driven entrepreneurship and illuminate the underlying mechanism of why women are less likely to create ventures in order to take advantage of the opportunity than men.
Design/methodology/approach
By drawing on human/social capital theory and expanding extant gender-related entrepreneurship literature, this study addresses how human and social capital mediates the relationship between gender and opportunity-driven entrepreneurship. A sample of 115,367 individuals across 62 countries drawn from the Global Entrepreneurship Monitor of 2016 was examined using multilevel logistic regression and Karlson-Holm-Breen (KHB) mediation analysis.
Findings
Findings of this study demonstrate that women’s lack of entrepreneurial relevant knowledge and skills, intrapreneurship experience as well as social networks with other entrepreneurs contribute to women’s less likelihood of engaging in opportunity-driven entrepreneurship than their male counterparts.
Originality/value
Compared to previous research mainly investigating macro-level determinants, this study further explores the explanatory factors affecting gender gaps in opportunity-driven entrepreneurship from the individual level. The findings provide an implication for public policy and give a direction to rethinking how to promote opportunity-driven entrepreneurship, especially for that led by women.