• 대한한방체열의학회지
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• 제6권1호
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• pp.69-75
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• 2008

Purpose: We investigated the effect of far-infrared radiating products on cold hypersensitivity of lower limbs using CST. Methods: 7 patients with cold hypersensitivity of lower limbs were investigated in this study. Exclusive criteria was skin diseases, spinal nervous disease and external wounds. They were asked to answer the VAS of cold hypersensitivity at baseline and after 3 weeks. We measured temperature of lower limbs with Spectrum 9000 MB (Dorex Inc, USA). We performed cold stress test (CST) by 3 thermographic observation using DITI : 1st was taken after 15 minutes resting at $25^{\circ}C$, the 2nd was immediately taken after 1 minute soak in $20^{\circ}C$ water, the 3rd was taken at 15 minutes after soak. We performed 3 times of CST : 1st CST was perfomed at baseline, 2nd CST was perfomred after 1 week and just observation, 3rd CST was performed after 1 week using far-infrared radiating products (lasner, UMT, Korea). Results: After using products, temperature of foot incresed more than thigh area, but there was no significance. There was no statistical difference of VAS, change of temperature and CST between before and after using far-infrared radiating products. Conclusion: There was no statistical effect of far-infrared radiating products on change of temperature of lower limbs.

• 해양환경안전학회지
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• 제22권3호
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• pp.286-295
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• 2016

With the results of observations in 2013 and 2014 including ocean buoys, in-situ investigations and wind data, we examined the spatio-temporal variation of cold water masses along the eastern coast of Korea. Usually, a cold water mass first appears along the northern part of the eastern coast from May to July, and then along the southern part of the eastern coast from late June to mid-August. Cold water masses appear 3~5 times a year and remain for 5~20 days in the southwestern part of the East Sea. A distinctive cold water mass appeared usually in mid-July in this area, the surface temperature of which was below $10^{\circ}C$ in some cases. During the appearance of a cold water mass in the southwestern part of the East Sea, the horizontal temperature gradient was large at the surface and a significant low water temperature below $8^{\circ}C$ appeared at the bottom level. This appearance of cold water masses clearly corresponded to southwesterly winds, which generated coastal upwelling.

• 한국미생물·생명공학회지
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• 제50권2호
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• pp.235-239
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• 2022

Psychrophiles have evolved to produce cold-adapted enzymes to enable survival in low-temperature environments. In this study, the cold adaptation of 5-enolpyruvylshikimate-3-phosphate synthase (CpsEPSPS) from Colwellia psychrerythraea, a model psychrophile, was analyzed. The optimum temperature for the activity of CpsEPSPS was found to be 25℃, with 35% activity remaining at 5℃. However, the unfolding temperature of CpsEPSPS was 54℃. This phenomenon is frequently observed in cold-active enzymes. As is the cases for most cold-active enzymes, the K_m values of CpsEPSPS for its substrates were higher than those of Escherichia coli EPSPS. These results indicate that CpsEPSPS is cold-adapted, but not perfectly.

• 대한기계학회논문집
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• 제18권5호
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• pp.1227-1234
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• 1994

A cold spot temperature control system for the batch annealing furnace has been established in order to reduce energy consumption which is essential to improve productivity and stabilize the properties of products. A relationship between annealing cycle time and gas flow rate is developed and also for the variation of coil cold spot temperature with time during heating, and actual temperature measurements at mid-width of each coil during soaking. The results of the temperature variation effect on the cold rolled steel sheet batch annealing are as follows. (1) Cooling rate increasing gradually with increasing atmospheric gas flow, but heating rate is hardly increasing without atmospheric gas component change. (2) In case of short time heating, the slowest heating part is the center of B coil and in case of ling time heating, the low temperature point moves from the center of coil to inside coil. (3) The outside of top coil is the highest temperature point under heating, which becomes the lowest temperature point under cooling. (4) Soaking time determination depends on the input coil width, and soaking time for quality homogenization of 1214 mm width coil must be 2 hours longer than that of 914 mm width coil.

• 한국방사선학회논문지
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• 제7권1호
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• pp.99-106
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• 2013

본 연구는 급성염증과 비슷한 지연성 근육통이 있을 때 초기 한냉치료를 적용함에 있어 냉기에 의한 냉각통증을 최소화하면서, 근육온도를 낮출 수 있는 방법으로 냉기단독과 냉기와 적외선 조사 병용을 적용하여 피부온도에 미치는 영향을 측정하고, 냉기와 적외선 병용치료의 효율성을 평가함과 동시에 초음파를 통한 근 두께를 바탕으로 등척성 근기능을 평가해보고자 하였다. 본 연구의 결과 냉기와 적외선 병용치료 시 냉기 단독치료보다 냉각통증의 빈도가 낮게 나타났으며, 냉각통증 자각 시점도 늦게 나타났다. 또한 충분한 냉기적용 후 피부온도가 재가온되는데 있어서 냉기를 2회 적용할 때가 1회 적용할 때 보다 더 느려지며, 냉기 단독치료보다 냉기와 적외선 광선 조사 병용치료 시 더 느려짐을 나타내어 2회 이상의 반복적인 냉기 적용이 냉기의 효용이 있다고 나타났다. 또한 상완이두근 두께 변화에 있어서 병용군이 대조군보다 더 크게 나타나 이 효과를 뒷받침하게 되었다. 이러한 연구결과 자료는 향후 급성염증이 있는 환자에게 한냉치료와 관련된 치료적인 자료로써 활용될 수 있을 것이라 생각되고 근골격계 초음파 진단기를 활용하여 통증에 대한 자각도를 간접적으로 표현하는 것이 구체화되어 임상에서 널리 활용될 것으로 보여진다.

• Journal of Ecology and Environment
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• 제32권3호
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• pp.145-148
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• 2009

To understand whether experience of cold season in reproductive behaviors in the adults of Amaurobius ferox, the paired adults of a female and a male were exposed under 'cold-treated environment' and 'not cold-treated environment', respectively. I investigated effects of the cold treatment on the brood production of A. ferox. In not cold treatment in which male-female pairs were formed in October at a temperature of $20^{\circ}C$ (${\pm}2^{\circ}C$) and continuously kept under not cold-treated environment, only 3 of 50 pairs successfully reproduced (reproduction was defined as the emergence of spiderlings). In cold treatment where individuals were kept in cold conditions for 3 months prior to pair formation, 57 out of 60 couples succeeded in reproducing. Females which did not experience the low temperature displayed strong aggressiveness toward males. This behavioral inhibition might the primary barrier to copulation of A. ferox that decrease following a period of low temperature. The reproductive inhibition might help the females to allocate the maximum amount of energy in a given environment to reaching the adult stage and to delay reproduction in unfavorable wintering conditions.

• Steel and Composite Structures
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• 제14권3호
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• pp.205-227
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• 2013

Current design standards do not provide adequate guidelines for the fire design of cold-formed steel compression members subject to flexural-torsional buckling. Eurocode 3 Part 1.2 (2005) recommends the same fire design guidelines for both hot-rolled and cold-formed steel compression members subject to flexural-torsional buckling although considerable behavioural differences exist between cold-formed and hot-rolled steel members. Past research has recommended the use of ambient temperature cold-formed steel design rules for the fire design of cold-formed steel compression members provided appropriately reduced mechanical properties are used at elevated temperatures. To assess the accuracy of flexural-torsional buckling design rules in both ambient temperature cold-formed steel design and fire design standards, an experimental study of slender cold-formed steel compression members was undertaken at both ambient and elevated temperatures. This paper presents the details of this experimental study, its results, and their comparison with the predictions from the current design rules. It was found that the current ambient temperature design rules are conservative while the fire design rules are overly conservative. Suitable recommendations have been made in relation to the currently available design rules for flexural-torsional buckling including methods of improvement. Most importantly, this paper has addressed the lack of experimental results for slender cold-formed steel columns at elevated temperatures.

• 대한기계학회논문집
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• 제19권10호
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• pp.2647-2656
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• 1995

The present work was performed to axially and radially investigate the local cold storage performance in the cylindrical tank with the spherical capsules inserted n-Tetradecane as a new cold storage material. The local cold storage performance of the capsules in the tank was experimentally investigated for the inlet temperature of -7, -5, -3, 0.deg. C, for the flow rate of 0.95, 1.89, 2.84, 6.00 l/min, and for the diameter ratio of 4.9, 9.0, 13.1. The local cold storage performance in the case of using water applied for the commercial ice-ball system was axially investigated by changing the flow rate only with the inlet temperature of -7.deg. C and the diameter ratio of 9.0 in order to compare with the performance in the case of using n-Tetradecane. For the case of using n-Tetradecane, the difference of cold storage period between the first and the seventh story was increased as the inlet temperature was increased and the flow rate was decreased. The capsules at the center of the tank showed the supercooling and the increased cold storage period compared with the capsules at the wall of the tank due to the small porosity and insufficient cold storage performance at the center of the tank as the diameter ratio is increased. The case using water showed worse cold storage performance due to comparatively large supercooling than the case using n-Tetradecane.

• 대기
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• 제28권4호
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• pp.383-392
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• 2018

This study investigates synoptic characteristics of cold surges over South Korea during winter season (December-February). A total of 63 cold events are selected by quantile regression analysis using daily mean temperature observations from 11 KMA stations for 38 years (1979/80-2016/17). Large-scale pressure pattern during the cold surges is well characterized by high over Siberia and low over Aleutian regions, which elucidates cold advection over the Korean peninsula. However, the large-scale pattern cannot successfully explain the observed sudden decrease of temperature during the cold surges. Composite analyses reveal that a synoptic-scale cyclone developing over the northern Japan is a key feature that significantly contribute to the enhancement of cold advection by increasing pressure gradient over the Korean peninsula. Enhanced sensible and latent heat fluxes are observed over the southern ocean of Korea and Japan during the cold surges due to temperature and humidity differences between the near surface and the lower atmosphere over the ocean. The evaporated water vapor transported toward the center of the surface cyclone and condenses in the lower-to-middle troposphere. The released energy likely promotes the development of the surface cyclone by inducing positive PV near the surface of the heating region.

• 한국초전도ㆍ저온공학회논문지
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• 제22권4호
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• pp.45-50
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• 2020

In this research, the variation of round-trip efficiency in a liquid air energy storage system (LAES) is calculated and an optimal configuration is found. The multiple stages of cold energy storage are simulated with several materials that process latent heat at different temperature ranges. The effectiveness in the charging and discharging processes of LAES is newly defined, and its relationship with the round-trip efficiency is examined. According to defined correlation, the effectiveness of the discharging process significantly affects the overall system performance. The round-trip efficiency is calculated for the combined cold energy storage materials of aqueous dimethyl sulfoxide (DMSO) solution, ethanol, and pentane theoretically. The performance of LAES varies depending on the freezing point of the cold storage materials. In particular, when the LAES uses several cold storage materials, those materials whose freezing points are close to room temperature and liquid air temperature should be included in the cold storage materials. In this paper, it is assumed that only latent heat is used for cold energy storage, but for more realistic analyzes, the additional consideration of the transient thermal situation to utilize sensible heat is required. In the case of such a dynamic system, since there is certainly more increased heat capacity of the entire storage system, the volume of the cold energy storage system will be greatly reduced.