• Title/Summary/Keyword: heat exposure

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The Impact of Environmental Health Factors on Extreme-heat Vulnerability Assessment in a Metropolitan City (환경보건적 요소가 도시 내 폭염 취약성 평가 결과에 미치는 영향 분석)

  • Lee, Won-Jung;Kang, Jae-Eun;Kim, Yoo-Keun
    • Journal of Environmental Health Sciences
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    • v.39 no.6
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    • pp.492-504
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    • 2013
  • Objectives: This analysis seeks to evaluate the impact of environmental health factors (EHF; e.g. hospital beds per capita, employees of medical institutions) on extreme-heat vulnerability assessment in Busan Metropolitan City during 2006-2010. Methods: According to the vulnerability concept suggested by the Intergovernmental Panel on Climate Change (IPCC), extreme-heat vulnerability is comprised of the categories of Exposure, Sensitivity, and Adaptive Capacity (including EHF). The indexes of the Exposure and Sensitivity categories indicate positive effects, while the Adaptive capacity index indicates a negative effect on extreme-heat vulnerability. Variables of each category were standardized by the re-scaling method, and then each regional relative vulnerability was computed with the vulnerability index calculation formula. Results: The extreme-heat vulnerability index (EVI) excepting EHF was much higher in urban areas than in suburban areas within the metropolitan area. When EHF was considered, the difference in the EVI between the two areas was reduced due to the increase of the Adaptive capacity index in urban areas. The low EVI in suburban areas was induced by a dominant effect of natural environmental factors (e.g. green area) within the Adaptive capacity category. Conclusions: To reduce the vulnerability to extreme heat in urban areas, which were more frequently exposed to extreme heat than others areas, public health and natural environments need to be improved in sensitive areas.

Thermoregulatory Characteristics of Feet and Legs in aspects of Covering Effect (피복효과면에서 본 발과 다리의 체온조절적 특성)

  • 이종민
    • Journal of the Korean Society of Clothing and Textiles
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    • v.23 no.7
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    • pp.965-970
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    • 1999
  • This study was conducted to investigate the thermoregulatory characteristics of feet and legs by comparing with the physiological responses according to the covering parts of lower limbs. Five healthy female subjects wore three types of clothing-covered legs and feet(LF-C) with long trousers and socks exposed the legs(L-E) with half trousers and socks and exposed the legs and feet(LF-E) with only half trousers-when the subjects rested at $25^{\circ}C$ and were exposed to 18$^{\circ}C$ for 90 min. Rectal temperatures (Tre) were maintained higher in LF-E than L-E and LF-C at both environments. Decreases of The after exposure to 18$^{\circ}C$ were significantly smaller in LF-E than L-E and LF-C and almost same in L-E and LF-C Heat production in both environments increases of heat production and weight loss after exposure to 18$^{\circ}C$ were not significant among three types of clothing. From these findings it would be suggested that the legs would play the little role of voluntary thermoregulation as vasoconstriction and the role of the legs depend on thermal conditions of feet while the feet play the positive role of voluntary thermoregulation in terms of heat conservation in cool environment.

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Effect of Heat Treatment on Radiation Shielding Properties of Concretes

  • Singh, Vishwanath P.;Tekin, Huseyin O.;Badiger, Nagappa M.;Manici, Tubga;Altunsoy, Elif E.
    • Journal of Radiation Protection and Research
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    • v.43 no.1
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    • pp.20-28
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    • 2018
  • Background: Heat energy produced in nuclear reactors and nuclear fuel cycle facilities interactions modifies the physical properties of the shielding materials containing water content. Therefore, in the present paper, effect of the heat on shielding effectiveness of the concretes is investigated for gamma and neutron. The mass attenuation coefficients, effective atomic numbers, fast neutron removal cross-section and exposure buildup factors. Materials and Methods: The mass attenuation coefficients, effective atomic numbers, fast neutron removal cross-section and exposure buildup factors of ordinary and heavy concretes were investigated using NIST data of XCOM program and Geometric Progression method. Results and Discussion: The improvement in shielding effectiveness for photon and reduction in fast neutron for ordinary concrete was observed. The change in the neutron shielding effectiveness was insignificant. Conclusion: The present investigation on interaction of gamma and neutron radiation would be very useful for assessment of shielding efficiency of the concrete used in high temperature applications such as reactors.

Reduced Protein Denaturation in Thermotolerant Cells by Elevated Levels of HSP70 (열내성이 유도된 세포에서 HSP70 단백질 증가에 의한 단백질 변성 감소)

  • Han, Mi-Young;Park, Young-Mee
    • The Korean Journal of Pharmacology
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    • v.32 no.3
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    • pp.433-444
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    • 1996
  • We describe a novel approach to evaluate quantitatively the amounts of denatured proteins in cells upon heat exposure. A thiol compound, diamide [azodicarboxylic acid bis (dimethylamide)] causes protein cross-linking with exposed sulfyhydryl residues of denatured proteins. Since denatured proteins expose normally well-hidden sulfhydryl groups, these will be preferentially cross-linked by diamide. Thus diamide acts to 'trap' denatured proteins. We observed that protein aggregates (high molecular weight protein aggregates, HMA) appeared on SDS-polyacrylamide gels run under non-reducing conditions and that the amount of HMA can be quantified by scanning the gels using a gas flow counter. Heating cells followed by a fixed dose of diamide exposure resulted in HMA increases in a heat-dose dependent manner, demonstrating that the quantitation of HMA could serve as a measure of heat-denatured proteins. We compared thermotolerant and nontolerant cells and found decreased HMA in tolerant cells upon heat treatment. As an attempt to examine the kinetics of protein renaturation (or 'repair'), we measured the amounts of aggregates formed by the addition of diamide at various times after heat shock. Such experiments demonstrate an equally rapid disappearance of HMA in previously unheated and in thermotolerant cells. Levels of HMA in tolerant cells increased significantly after electroporation of HSP70 specific mAbs, suggesting an involvement of HSP70 in reducing HMA levels in thermotolerant cells upon heat exposure. Immunoprecipitation studies using anti-HSP70 antibody indicated an association of HSP70 with heat-denatured proteins. Our results suggest that heat induces protein denaturation, and that elevated level of HSP70 present in thermotolerant cells protects them by reducing the level of protein denaturation rather than by facilitating the 'repair' (or degradation) process.

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Surface morphology modification of vertically-aligned carbon nanotubes by water vapor exposure

  • Adil, Hawsawi;Jeong, Goo-Hwan
    • Proceedings of the Korean Vacuum Society Conference
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    • 2015.08a
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    • pp.238.2-238.2
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    • 2015
  • Surface modification of vertically-aligned carbon nanotube (VACNT) is essential in order to meet specific demands for particular applications such as field emission displays, heat dissipation device and potential sun energy conversion due to their superior electrical and thermal conductivity and strong light absorption. In this study, we observe the effect of exposure to water vapor on a different lengths of the surfaces of VACNT. The study was conducted on three different lengths of the VACNT: short length around $200{\mu}m$, medium-length around $500{\mu}m$, and high length around 1 mm. Water exposure time ranges between 2-10 min and temperature of the water ranges from 60 to 120 oC. The result of water vapor exposure mainly show that increasing the exposure time and water temperature give rise to increase of the speed of change on the surface of the VACNT. Especially, the shorter VACNT change their surface morphology most rapidly.

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Influence of Regular Jjimjilbang Exposure on Farmers' Physiological Responses (정기적인 찜질노출이 농업인의 생리반응에 미치는 영향)

  • Choi, Jeong-Wha;Song, Eun-Young;Park, Joon-Hee
    • Journal of the Korean Home Economics Association
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    • v.46 no.1
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    • pp.39-45
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    • 2008
  • We analyzed the effects of regular Jjimjilbang(Korean sauna) exposure on the physiological responses in seven elderly farmers(Male=3, Female=4). Jjimjil training group took a bath in Jjimjilbang 8 times twice a week. Jjimjibang exposure was limited three times per day. Rectal temperature, total sweat rate, body fat (%), blood pressure, pulse, $Na^+$ concentration in sweat, and subjective sensation were measured during Jjimjil training exposure. The results are as follow: During Jjimjil exposure, changes of rectal temperature in male farmers were more stabilized than female farmers. The gradual decrease in total sweat rate and Na+ concentration in sweat was observed in both sexes. After Jjimjil exposure, the decrease in blood pressure was observed in both sexes, but not observed changes according to regular Jjimjil exposure. Subjective thermal comfort sensation was changed positively. In conclusion, the regular Jjimjil exposure has positive effects upon improvement in regulation of body temperature, blood pressure, and $Na^+$ concentration especially in heat tolerance.

Analysis of Changed Bio-Signal to Radiation Exposure of Nuclear Medicine Worker (핵의학 종사자의 방사선 피폭에 따른 생체신호 변화 분석)

  • Lee, Hwun-Jae;Lee, Sang-Bock
    • Journal of Radiation Protection and Research
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    • v.32 no.1
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    • pp.27-34
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    • 2007
  • In this paper, We are evaluated about bio-signal between general workers and nuclear medicine workers which is more radiation exposure relatively. In order to reciprocal evaluated two group, we experimented nuclear medicine workers in Chung-Buk National University Hospital at department of nuclear medicine and worker in Chon-Nam National University Hospital at CT room, general radiographic room, medical recording room, receipt room, general office room. Used of experimental Equipments as follows, for a level of radiation measurement by pocket dosimeter which made by Arrow-Tech company, for heart rate and blood pressure measurement by TONOPORT V which made by GE medical systems company, for heat flux and skin temperature and energy expenditure measurement by Armband senseware 2000 which made by Bodymedia company. Result of experiment obtains as follows: 1) Individual radiation exposure is recorded 3.05 uSv at department of nuclear medicine and order as follows CT room, general radiograpic room, medical recording room, receipt room, general office room. Department of nuclear medicine more 1.5 times than other places. 2) Radiation accumulated dose is not related to Heat flux, Skin temperature, Energy expenditure. 3) Blood pressure is recorded equal to nuclear medical workers, general officer, general people about systolic blood pressure and diastolic blood pressure. Compared to blood pressure between nuclear medical works which is more radiation exposure and other workers was not changed. Consequently, more radiation exposed workers at nuclear medicine field doesn't have hazard.

Meat quality and safety issues during high temperatures and cutting-edge technologies to mitigate the scenario

  • AMM Nurul Alam;Eun-Yeong Lee;Md Jakir Hossain;Abdul Samad;So-Hee Kim;Young-Hwa Hwang;Seon-Tea Joo
    • Journal of Animal Science and Technology
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    • v.66 no.4
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    • pp.645-662
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    • 2024
  • Climate change, driven by the natural process of global warming, is a worldwide issue of significant concern because of its adverse effects on livestock output. The increasing trend of environmental temperature surging has drastically affected meat production and meat product quality, hence result in economic losses for the worldwide livestock business. Due to the increasing greenhouse gas emissions, the situation would get prolonged, and heat exposure-related stress is expected to worsen. Heat exposure causes metabolic and physiological disruptions in livestock. Ruminants and monogastric animals are very sensitive to heat stress due to their rate of metabolism, development, and higher production levels. Before slaughter, intense hot weather triggers muscle glycogen breakdown, producing pale, mushy, and exudative meat with less water-holding capacity. Animals exposed to prolonged high temperatures experience a decrease in their muscle glycogen reserves, producing dry, dark, and complex meat with elevated final pH and increased water-holding capacity. Furthermore, heat stress also causes oxidative stresses, especially secondary metabolites from lipid oxidation, severely affects the functionality of proteins, oxidation of proteins, decreasing shelf life, and food safety by promoting exfoliation and bacterial growth. Addressing the heat-related issues to retain the sustainability of the meat sector is an essential task that deserves an inclusive and comprehensive approach. Considering the intensity of the heat stress effects, this review has been designed primarily to examine the consequences of hot environment temperatures and related stresses on the quality and safety of meat and secondarily focus on cutting edge technology to reduce or alleviate the situational impact.

Experimental Analysis of Radiative Heat Interchange on Furnace Exit Plane of a Steam Boiler

  • Ahn, Kook-Young;Antonovsky, Vjacheslav-Ivanovich
    • Journal of Mechanical Science and Technology
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    • v.15 no.2
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    • pp.239-247
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    • 2001
  • Measured radiative heat fluxes on the furnace exit plane of a heavy duty power boiler of steam output 1650 T/h are discussed. A high-ash pulverized bituminous coal was used. Such measurements are necessary to improve heat fluxes inside a steam boiler furnace was manufactured. An extra small heat radiation sensor was placed in the water cooled head of the probe. The sensor had no direct contact with furnace gases and measured only the radiant energy. There was no exposure to convective heat transfer. With the radiometric probe, one can obtain a spherical indicatrix of radiation intensity as well as hemispherical radiative heat flux incident on any surface passing through a measuring point inside the furnace. Thus, the quantity of radiation energy, passing through the furnace exit plane, to the convective heating surfaces and the quantity of radiation energy going in the opposite direction were measured. A formula for relative radiative heat flux on the furnace exit plane has been proposed.

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