Earticle

추운환경에서 옥외 작업자들은 추위스트레스에 시달린다. 특히 그들은 신체보다 발과 같은 말단부에서 더 추위를 지각한다. 일부 제조사들은 추운환경 작업자들을 위하여 리튬이온 배터리를 부착한 발바닥 발열패드를 공급하고 있다. 이것은 족부 또는 신체의 온열감각 개선에 기여할 수 있을 것으로 보이지만 그렇지 않을 수도 있다. 그러나 이 발열패드의 열쾌적 개선 성능에 관한 평가가 보고되지 않고 있다. 따라서 본 연구는 추운환경에서 발열패드를 착용한 피험자들 대상으로 열쾌적 개선 정도를 평가하고자 한다. 본 연구는 12명의 피험자를 다음의 4단계 열환경에 각 20분간씩 노출시키면서 온열반응을 측정하였다. 1) Ta 22℃(PMV; 0), 2) Ta 10℃(PMV; -3)에서 발열패드 전원을 끈 상태(case A), 3) Ta 22℃, 4) Ta 10℃에서 발열패드 전원을 켠 상태. 본 연구는 ASHRAE 7척도, 11척도에 의한 신체 각부의 주관적온열반응평가(TSV), 평균피부온도(MST), 발바닥피부온도를 측정 변수로 하였다. 발열패드 ON, OFF 두 사례 비교에서 MST 등은 오히려 감소하였고, 7척도 기준 전신 TSV는 미미한 수준으로 증가하였으며, 족부 TSV는 1.33 증가하였다. 결론적으로 발열패드는 족부의 온열감각 만을 증대시킬 뿐 전신 온열감각 개선에는 영향을 주지 못하는 것으로 판단된다.

The out door workers suffer from the cold stress in the cold environment. Especially, the out door workers more perceive the cold sensation at the limbs such as feet than the body. The manufactures of wears supply the portable thermo soles with the 2600mAh lithium ion battery for the working people in the cold environment. The thermo soles seems to be that it contribute to the thermal sensation in the feet and whole body or not. However, the improvement of thermal comfort on the thermo soles in the cold environment was not evaluated in the recently research. Therefore, this research aim is to the evaluation on the improvement of thermal comfort of subjects with the thermo soles in the cold environment. The research conduct the experiments on the thermal responses of 12 subjects in serial four conditions each 20 minutes; 1) air temperature is 22℃(PMV; 0), 2) air temperature is 10℃(PMV; -3) and not heating the sole(case A), 3) air temperature is 22℃, 4) air temperature is 10℃ and heating the sole(case B). The research measures the variations that ASHRAE 7 scale and 11 scale Thermal sensation vote(TSV, the whole body, the upper half of the body, the lower half of the body, the feet), Mean skin temperature(MST), Sole skin temperature(SST) of the subjects in each experiment conditions. In comparison with two cases, the experiment shows that MST, SST of subjects wearing thermo soles were decrease, whole body 7 scale TSV of the subjects were insignificant increase, and the feet 7 scale TSV of the subjects were 1.33 increase. In conclusion, the thermo soles influence only the thermal comfort of the feet but it not influence the thermal comfort of whole body, the upper half of the body.

The food cold chain refers to a technology and distribution supply chain applied to maintain a constant temperature suitable for the product from production (harvest) to delivery to consumers. In particular, in Korea, the insulation material used in the food cold chain is mostly EPS (Expanded Polystyrene), which is used as a transport container for various food cold chains. However, according to the government's eco-friendly policy, companies charge environmental contributions to the use of EPS, but due to its low price and convenience of handling, it is still used as a container for delivering food. In this study, in order to measure the domestic delivery environment of general refrigerated foods, changes in impact, temperature, and humidity during transport of the EPS packaging system containing foods and ice pack refrigerants were measured. As a result, there were 2?3 sections in which a high impact force of 40 G or more was generated during transport. This can cause damage to the product and EPS container. The difference in temperature and humidity changes by parcel transport routes is more than 30%, so it is necessary to present accurate standards for the domestic cold chain distribution environment. As a result of microbial experiments. the transportation period had a dominant effect on the increase in total viable count and E. coli count.

The reduction of running energy cost and fossil fuel pollutant is the big issue in the building industry, therefore the energy authority guide to the low room temperature in the heating season. However, the occupant feel unsatisfying TS(Thermal sensation) in actual condition that the room of low temperature as under 18℃. The heating on local body as sole and buttock is useful auxiliary way in the low temperature room in the heating season, but the papers on the human body response with the local body heating were no sufficient. This study aim is how to the human body responses as the change of CT(Core temperature) and MST(Mean skin temperature, ISO 9886 4 point), and TSV(Thermal sensation vote, ASHRAE 7 scale) of human body through the measures of CT, MST, PMV(Predicted mean vote, ISO 7730), the questionnaire TSV on three cases subjects in slightly cool ambient that the first is only heating the sole, the second is only heating the buttock, the third is the sole and buttock heating. And tow subjects participate in 6 days measuring in mid winter, the subjects sit in the half hour of each condition phases that the first is non heating corridor(Approximately ambient temperature 8±1℃, PMV is under -3.0), the second is in the room(16±1℃, PMV is approximately -1.5), the third is sole and buttock touching that the EHC(Electric heating cushions) in the room(16±1℃, PMV is same to second phase), the fourth is untouching the heating cushions in the comfort room(23±1℃, PMV is approximately 0.5). In conclusion, the CT of subjects were constant in every steps in all cases but the MST and TSV were slightly change that when local body heating. The change of MST were as follows; the first case Δt is 0.11℃, the second case Δt is 0.16℃, the third case Δt is 0.21℃. The difference of TSV were as follows; the first case is 0.75, the second case is 1.5, the third case is 2.0. According to this study, the heating of human local body as sole and/or buttock were a good auxiliary way of the heating in the slightly cool ambient in the winter season.

In this study, the experimental and analytic investigation with cold air system has been performed for improving the working environment of the conventional grinding fluid. Very simple cold air system was developed which could replace by the conventional grinding fluid system. The identification of heat of grinding Bone is very important for precision grinding. The experimental data was analysed to investigate the heat which was transferred to the workpiece. It was found that 45∼55％ of the total energy for dry grinding, 22∼28％ for wet grinding, and 32∼35％ for cold air system are conducted to the workpiece in grinding with cubic boron nitride wheel. Cubic boron nitride wheel could reduce the residual stress and thermal demage comparing with aluminium oxide wheel, because cubic boron nitride wheel has very high extreme thermal conductivity.

The results of internal temperature. productivity and immunity analysis of the laying hen house by the thermal environment and the supply of cold drinking water were as follows. The external temperature was changed from the minimum of 18℃ at night and the maximum of 36℃ during the day, and the internal temperature of the laying hens varied from 20~31℃. Thermal imaging analysis showed that the body temperature of the laying hen decreased by 2.4℃ with the supply of drinking water. The laying hen amount increased 2.36g and laying hen rate increased 3.62%p. Albumin increased 6.1%, decreased AST 15%, and decreased cholesterol 12.7%. Immune activators increased and T cells and B cells increased to increase immunity.

This study aims at providing a basic data for the development of high energy efficient environment system in the cage (poultry buildings) and cold potable water supply to reduce the summer heat stress. For this study, the cage area size was 273m 2 and the air-to-water heat pump capacity was 20RT for heating and cooling. As the result of this study, the temperature of the drinking water supplied by heat pump was maintained at the set temperature of 15℃. However, the water temperature of control was 23~28 ℃ due to the effect of outside temperature. The average internal cage temperature was 25.3 ℃ in the test group and 28.1 ℃ in the control group, which was 2.8 ℃ higher than that of the control group. The relative humidity was 76.2% in the test group and 75.0% in the control group. The broiler drank 23.2 L / day in the test group and 21.5 L / day in the control group. Daily feed intake was 937 g and and 725 g in the cold water and control water respectively. The feed intake of 212 g was higher than that of cold water. The feeding rates were 1.8 and 1.9. Body weights were 1,523 g and 1,164 g in the cold water and control water respectively. The weight gain was 359 g in the test group fed with cold water and 392 g in the control group. When compared with the control group, the mortality rate was reduced by 84% in the cold water feeding test. It is necessary that future research will continue to reduce the incidence of such livestock accidents.’.

The effect of local heating on physiological and psychological thermal responses were examined. Subjects were five healthy female students in a climatic chamber controlled at $25^{\circ}C$ and 50% r.h. Each subject's tympanic temperature, skin temperature, blood flow rate, thermal sensation and so forth, were measured during the experiment, which consisted of 30 minutes of control, 30 minutes of local heating and 30 minutes of recovery. The surface temperature of the 15$\times$20 cm heating pad was controlled by circulating 45$^{\circ}C$ water through a silicon tube. The heated regions were head, neck, chest, back, abdomen, loin, upper arm, forearm, hand, thigh, lower leg, foot. Results showed that physiological and psychological thermal responses to local heating were different among the heated body regions. The skin temperature beneath the heating pad increased significantly. Lower leg skin temperature(10.67$^{\circ}C$) was highest and was high in order of loin(9.14$^{\circ}C$), abdomen (8.99$^{\circ}C$), upper arm(8.9$0^{\circ}C$), thigh(8.53$^{\circ}C$), foot(8.47$^{\circ}C$), back(8.05$^{\circ}C$), chest(7.15$^{\circ}C$), forearm(7.07$^{\circ}C$), hand(6.86$^{\circ}C$), neck(5.63$^{\circ}C$), head(4.19$^{\circ}C$). The tympanic temperature increased on head and forearm local heating. While the others were tendency to falling. The change of blood flow was classified into three groups, subject HB and JM thermoregulate in finger, subject KS and SS in toe and subject KA changed a little in both part of the body, The effect of local heating on head and upper arms were large, but the change of regional thermal sensation was large on thigh, lower legs and feet local heating.(중략)

Objective: An experiment was conducted to evaluate the effects of dietary glutamine (Gln) and arginine (Arg) supplementation on performance, intestinal morphology and ascites mortality in broilers. Methods: A total of 675 day old chicks were randomly allocated to 9 experimental groups in a $3{\times}3$ factorial arrangement based on a completely randomized design with 5 replicates of 15 chicks. Three levels of dietary Gln (0%, 0.5%, and 1%) and Arg (100%, 130%, and 160% of Ross recommendation) supplementation were used in ascites inducing condition ($15^{\circ}C{\pm}1^{\circ}C$) from 7 to 42 days of age. Results: Dietary supplementation of Gln increased body weight gain during grower, finisher and total periods (p<0.05) and increased feed intake during total period. Ascites mortality was decreased by Gln supplementation (p<0.05). Gln supplementation increased the villus height (VH) and crypt depth (CD) in duodenum and jejunum (p<0.05). Arg supplementation decreased CD in duodenum and jejunum, and increased ileum villus width (VW) and also VH/CD ratio in duodenum and jejunum (p<0.05). Both Gln and Arg increased the goblet cell number (GCN) in duodenum whereas Gln supplementation decreased GCN in jejunum and ileum (p<0.05). The $Gln{\times}Arg$ interaction were observed for right ventricle (RV)/total ventricular (TV) ratio, VH, VW, CD, VH/CD. Conclusion: It was concluded that dietary 0.5% Gln alone or along with 130% Arg of Ross requirement, improve the intestinal morphology and performance and hence decrease the ascites mortality in broiler chickens with cold induced ascites.

This article investigates the way in which intermedia [int?media] came into play as an artistic discourse and practice by illustrating key intermediate exhibitions/events held in 1960s Japan. I argue that intermedia in Japan emerged not only as an aesthetic discourse but also took its shape on the basis of the US-Japanese network of artists/institutions/corporations in the context of the cold war geopolitics. To reveal this aspect, I explore the notion of ‘environment’ that had been interrogated as a pre-concept or prerequisite of intermedia in 1960s Japan by focusing on an exhibition, From Space to Environment [K?kan kara Kanky? e], held in 1966, Tokyo. Through this exhibition, a new media environment that attempted to push the boundaries of different artistic genres and materials was explored by artists, graphic designers, architects, media artists, critics, and so forth. These collective practices led to the emergence of intermedia in Japan. I explore the course of how intermedia was introduced to Japan by a Japanese filmmaker and video artist, Iimura Takahiko, and how his thoughts were developed based on his transpacific artistic practices. I specifically show that his works of intermedia revealed the interrelations between artistic practices and everyday lives. I finally examine an intermedia event, Crosstalk Intermedia 1969, that was held at the Yoyogi National Gymnasium and was the largest intermedia event before Expo ‘70. This Crosstalk event was an experimental field for various artists most of whom were scheduled to show their media works in the coming event of Expo ‘70. The artists from various fields displayed their intermedia artworks by exploring new media technologies and their environment.; it was also an ambivalent media event where techno-utopian visions and geopolitical context were entangled together, which served as a pre-show of Expo ‘70.

The outcomes of solution annealing and stress corrosion cracking in cold-worked 316L austenitic stainless steel have been studied using x-ray diffraction (XRD) and the slow strain rate test (SSRT) technique. The good compatibility with a high-temperature water environment allows 316L austenitic stainless steel to be widely adopted as an internal structural material in light water reactors. However, stress corrosion cracking (SCC) has recently been highlighted in the stainless steels used in commercial pressurized water reactor (PWR) plants. In this paper, SCC and inter granular cracking (IGC) are discussed on the basis of solution annealing in a chloride environment. It was found that the martensitic contents of cold-worked 316L stainless steel decreased as the solution annealing time was increased at a high temperature. Moreover, mode of SCC was closely related to use of a chloride environment. The results here provide evidence of the vital role of a chloride environment during the SCC of cold-worked 316L.

The development of passive buildings has been given more attention to realize the energy-saving and low carbonization of buildings. Controlling thermal bridges in the external envelope is the primary technological approach in achieving low-energy passive buildings. There are many climatic zones in China, and it is necessary to conduct in-depth research on different environments to clarify the impact of thermal bridge treatment on passive buildings under special conditions. Therefore, the researchers developed a simulation model in Ansys fluent in conducting a 24-hour transient simulation study of the thermal bridge design for passive buildings in cold, dry climates. The simulation model consists of the indoor environment and building envelope. Then the actual meteorological parameters in cold and dry climate regions were used as the boundary conditions of the proposed model to be close to reality. In this case, the temperature distribution inside the envelope layers, indoor temperature variation, and thermal energy consumption were studied under passive design (without thermal bridge) and conventional design (with thermal bridge). The analysis results showed that better thermal bridge treatment made it more difficult for the external cold air to pass through the outer structural layer of the envelope to the inner structural layer under the passive design. In addition, the indoor temperature under the passive design was 1oC higher than that under the conventional design. Moreover, the heating energy consumption under the passive design was about 0.8W/m2 lower than that under the conventional design. The findings of this paper are intended to provide reference for designers and researchers in understanding the impact of thermal bridges on the indoor thermal environment of passive buildings in cold and dry climates.

We investigated a relationship between self-identified cold tolerance and hand cold tolerance while wearing a single glove under cold stress. Twenty seven young adults (24 females and 3 males) participated in a hand dexterity test using a Purdue Pegboard and a finger cold-induced vasodilation (CIVD) test in a 3.6oC water at an air temperature of 5.6 ± 0.2oC. All subjects were divided into either a cold-tolerant (High self-identified cold tolerance, HSCT, 11 subjects) or intolerant group (Low self-identified cold tolerance, LSCT, 16 subjects) according to their self-identification. The results showed that (1) the HSCT group showed higher finger temperatures during the finger CIVD test than the LSCT group (p<0.05), (2) there was no significant difference in mean skin temperature between two groups, but hand and finger temperatures were higher for the HSCT than the LSCT (p<0.05), (3) heart rate showed more stable tendency during the CIVD test for the HSCT group compared to the LSCT group, (4) the HSCT group expressed less cold, less uncomfortable, and less painful while the CIVD test when compared to the LSCT group (p<0.05), and (5) hand dexterity under cold stress reduced by 27% for the bare hand condition and 13% for the gloved hand condition (p<0.001), with no difference between HSCT and LSCT. To sum up, wearing a single glove under cold stress was beneficial to improve another bare hand’s dexterity and the beneficial effect of wearing the single glove was greater for the self-identified cold-tolerant individuals than for intolerant individuals.

본 연구는 한랭 환경 하에서의 인체의 국소 가온 자극이 생리, 감각반응에 끼치는 영향을 검토했다. 건강한 성인여자 7명을 대상으로, 기온 $25^{\circ}C$, 습도50%의 환경 하에서 균일한 국소 가온을 부하 했을 때 피부온, 고막온, 손가락, 발가락 혈류량, 온냉감, 쾌적감의 반응에 미치는 영향을 검토한 결과는 다음과 같다. 1) 국소가온에 의해 가온 부위 피부온은 유의하게 상승하고 가온 부위에 따라 상승도에는 유의한 차가 보였다. 2) 국소가온에 의해 고막온은 머리의 가온 시에 높은 상승, 전완의 가온 시에 상승하고, 다른 가온 부위에서는 하강의 경향이 보였다. 3) 국소가온에 의해 혈류량의 변화는 3개의 군으로 분류된다. 가온과 함께 손가락 혈류량이 증가하는 군, 발가락 혈류량이 변화하는 군, 양쪽의 혈류량이 적게 변화하는 군으로 나누어진다. 이것을 각 피험자의 평균 피부온 수준 즉 체온조절 수준과 관계 있는 것으로 논할 수 있다 4)국소 가온에 의해 각 부 위 피부온으로의 파급효과는 머리, 상완의 가온 시에 크지만 대퇴, 하퇴 다리의 가온 시에는 대부분의 부위에서 영향이 보이지는 않았다. 5) 이와 같이 국소 가온에 의 한 생리, 감각반응은 가온 부위에 따라 다르고 머리, 상완의 가온 시에는 생리반응이 크고 하퇴, 다리의 가온시에는 국소의 감각변화가 컸다.

This study investigated the effects of regional down insulation on thermal sensation, thermal comfort, and shivering responses during cold exposure while wearing a baffle-type padded jacket. Eight healthy young males (23.4 ± 2.5 y) participated in nine trials in a climate chamber set at ?9.7 ± 1.0°C, each lasting 60 min in a seated posture. The experimental padded winter jacket was divided into eight compartments (chest, front waist, abdomen, upper back, lower back, hips, upper arms, and forearms), and insulation was selectively removed from one compartment per trial, with the fully filled jacket serving as the control. Whole-body and local thermal sensation and comfort were assessed every 10 min using standardized categorical scales, and shivering frequency and location were recorded. Removal of insulation from the chest, abdomen, or hips did not significantly affect whole-body thermal sensation or thermal comfort. In contrast, removing insulation from the upper back or upper arms significantly increased local cold sensation (p < 0.05) and reduced thermal comfort. Clothing insulation measured by a thermal manikin decreased only slightly (≤ 0.07 clo) when any single compartment was unfilled, suggesting minimal overall thermal impact. These results indicate that maintaining insulation at the upper back and upper arms is critical for preserving thermal sensation/comfort and reducing shivering, whereas partial insulation reduction at the chest or abdomen is possible without compromising overall thermal perception. The findings provide practical insights for designing energy-efficient winter jackets that minimize down usage while maintaining wearer comfort and supporting behavioral thermoregulation.

This study was to investigate the thermal physiological and psychological responses of clothing ensembles including long padded jackets with two different filling types (goose down and light weight polyester) in two cold environments with different velocities (less than 0.15 m·s-1 [windless condition] and 1.5 m·s-1 [windy condition] at an air temperature of 10°C). Ten males (22.6 ± 1.5 y in age, 175.9 ± 2.6 cm in height, 70.1 ± 4.5 kg in body weight, 1.86 ± 0.06 m2 in body surface area) participated in four experimental conditions. The results showed that there were significant differences by air velocity in mean skin temperature (mean Tsk), changes in mean Tsk, and energy expenditure (P<0.05). However, there were no significant differences by the filling materials in the windless condition, while significant differences were found in thigh, hand, and foot temperatures, microclimate temperatures on the chest and thigh for the windy condition by the filling material (P<0.001). It is recommended to wear a goose-down padded jacket rather than a polyester padded jacket in a cold and windy environment, but it seems that polyester padded jackets would provide similar insulation values as those of goose-down jackets in cold environments without any sensible airflow.