• 한국의류산업학회지
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• 제22권6호
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• pp.853-861
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• 2020

Various types of clothing are being developed to boost thermal comfort during cold winters along with research on change of body temperature when heating is applied. There is a noticeable behavioral difference by gender when using heating panels in a cold environment; however, research on women has been insufficient. This study find a temperature range that provides sustainable thermal comfort in a low temperature environment by observing temperature and change of temperature when subjects are classified according to physical activities or cold sensitivities. For the study results, 8 women in their 20s were subjected to experiment in a low temperature environment for 75 minutes (sitting position: 30 min., running: 15 min., and sitting position: 30 min.). Subjects were asked to turn on/off the heating panel freely to analyze the range of comfortable temperature and clothing microclimate; in addition, skin temperature and heating panel temperature were measured and analyzed at 9 points. As a result, temperature at which subjects turn on and off the heating panel indicated a statistically meaningful difference between the cold sensitivity group depending on exercise or non-exercise. The range of comfortable abdomen temperature was wider than the lower back and was significantly reduced when the subject was running. The range of comfortable temperature was also largest for the heating panel temperature, microclimate, and skin temperature in suggesting that adequate adjustment will be required depending on the surrounding environment or movement of the wearer.

• Journal of Plant Biology
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• 제31권4호
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• pp.299-307
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• 1988

The electron transport activities of choloroplasts isolated from hte detached rise (Oryza sativa L. cv. Chucheong) leave stored under low temperature(4$^{\circ}C$) with light illumination were investigated to understand the role of light in the low temperature inhibition of photosynthesis in the chilling-sensitive plants. Chlorophyll content of the detached leaves upon incubation at 28$^{\circ}C$ and 4$^{\circ}C$ in the dark was also measured. The rice seedlings were grown with Hoagland medium in the growth chamber of 28$^{\circ}C$ temperature and 400 ft.c fluorescent light with the photoperiod of 16 h. Although chlorophyll content of the detached leaves stored in the dark declined by 61.7% after 28$^{\circ}C$ treatement, there occurred only 5.2% decrease of chlorophyll with 4$^{\circ}C$ treatment. Low temperature treatment(4$^{\circ}C$) for 6 days brought about decreases in total photosystem(PS II＋PS I) activities by 35.2% and 73.6% in te presence and absence of light, respectively, while after 28$^{\circ}C$ treatment of the detached leaves for 6 days in the dark there was only 27.6% decrease in PS II＋PS I activity. PS II activities were also decreased by 35.6% and 72.2% in the light and dark, respectively. PS I activities were decreased slightly, however, by 7.6% and 16.2% in the light and dark, respectively. Investigations into DPClongrightarrowDCPIP and NH2OHlongrightarrowDCPIP activities revealed that low temperature inhibition of PS II activities was not due to the inactivation of the water oxidation capacity at low temperature. It was concluded that light protects the electron transport activities of isolated rice chloroplasts from the inhibitory effect of low temperature in the detached leaves.

• Fisheries and Aquatic Sciences
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• 제4권3호
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• pp.112-119
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• 2001

Aim of this research is to investigate the effect of temperature shocks on the physiological responses of cultured olive flounder (Paralichthys olivaceus) and black rockfish (Sebastes schlegeli). Olive flounder and black rockfish were suffered with high and low temperature shocks for 4 and 8h, respectively, in laboratory conditions and then the changes in glucose, lactate, total protein, uric acid, and triglycerides-glycerol in blood plasma were analyzed. We observed that lactate and uric acid increased for up to 4h and then decreased for up to 8h by the high and low temperature shocks, and total protein decreased for up to 4h and then recovered for up to 8h by the high temperature shock in both fishes. Glucose by the high and low temperature shocks and triglycerides-glycerol by the low temperature shock increased for up to 4h, and then decreased in olive flounder, but increased for up to 8h in black rockfish. From the result, we speculated that the two fishes have an interspecific variation in the regulatory systems of glucose and triglycerides-glycero1. Glucose would play important role as an energy source during the temperature shocks and for an intermediate substance for low temperature tolerance, and glycerol of triglycerides-glycerol would play an important role for low temperature tolerance. In olive flounder, the turnover of chemical change by temperature shock took more than 4h, all chemicals returned almost to the initial level for up to 8h, but fish death followed only in 8h with the high temperature shocked group within two days. Therefore, we suggested that fish would be damaged severely by the longer time exposure of high temperature and mortality would occur after a certain time later than the shocked time as a post-effect.

• 한국산학기술학회논문지
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• 제7권3호
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• pp.344-349
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• 2006

[ $60{\sim}70nm$ ] 급의 design rule을 가진 고집적 반도체 소자를 제작하려면, 트랜지스터 형성 이후의 공정에서 thermal budget을 줄이기 위하여 공정의 온도를 낮추는 것이 중요하다. 본 연구에서는 고온의 습식 산화막을 대체할 수 있는 저온의 LPCVD (Low-Pressure Chemical Vapor Deposition) $SiO_2$(LTO : Low-Temperature Oxide) 박막 증착공정을 제시하였으며, ONO (Oxide/Nitride/Oxide) 구조의 커패시터를 형성하여 증착된 LTO 박막의 전기적인 신뢰성을 평가하였다. LTO 박막은 5 MV/cm 이하의 전기장 영역에서는 고온의 습식 산화막과 크게 차이가 없는 누설전류 특성을 보였으나, 더 높은 전기장의 영역에서는 훨씬 더 우수함을 보여주었다.

• 한국식품저장유통학회지
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• 제6권2호
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• pp.143-147
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• 1999

양파의 저장조건을 저온(2-4$^{\circ}C$, 80% RH), 움식(3-15$^{\circ}C$, 75-85% RH), 실온방열(10-23$^{\circ}C$, 75-98% RH) 및 상온(2-$25^{\circ}C$, 62-72% RH)으로 구분하여 저장 중 물리적 및 화학적 변화를 조사하였다. 저장 중 양파의 발아율은 저온 저장된 양파를 제외하고는 모두 높게 나타났으며, 저온 저장된 양파에서는 저장 11개월까지 거의 발아되지 않았다. 양파의 부패율은 실온방열 저장된 양파를 제외하고는 7개월까지 낮았으나 7개월 이후에는 모두 급격히 부패되었다. 중량감소는 기간이 경과함에 따라 계속되었으며, 저온 저장된 양파에서 가장 적게 일어났다 수분함량은 저온 및 움식 저장된 양파에서 증가하였으나 실온방열 및 상온에서 저장된 양파에서는 감소하였다. 전당과 환원당의 함량은 시간의 경과와 함께 완만하게 감소하였다. Vitamin C는 저장 중 큰 변화가 없었으나 저온 저장된 양파의 경우에는 다소 증가하였다.

• Journal of Plant Biology
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• 제17권4호
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• pp.31-37
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• 1974

Seedlings of Nongbaek representing strong cold tolerant variety of rice plant, Jinheung of medium variety and Tongil of weak variety were used respectively for the present study. These seedlings were water cultured in phytotron which maintained at the daytime and night temperature of 30-$25^{\circ}C$, 20-2$0^{\circ}C$, 20-15$^{\circ}C$ and 15-1$0^{\circ}C$. The growth rate of plant height, tillering rate, increase in dry weight and absorption pattern of important mineral nutrients at their early growth stage under each temperature conditions were observed. Generally, it appeared that Nongbaek was more active in the growth of plant height than Jinheung, and Jinheung was more active than Tongil under low temperature condition. The tillering rate of these three varieties was equally rapid while it was decreased in the order of weak cold tolerant variety, such as Tongil, Jinheung and Nongbaek as the temperature declined gradually. The dry weigh tincreasing curve showed almost the same pattern in the varieties at the treatment of each temperature. Under low temperature conditions, Nongbaek showed higher absorption rate of N per dry weight and higher absorption amount of per plant body, Jinheung followed and Tongil was the lowest. The absorption amount of P2O5 increased in the top part compared with the roots as temperature rose and decreased as temperature declined. There seemed to be no difference of absorption among the varieties which have different cold tolerance each other. Under low temperature the absorption rate of K per dry weight was high, as a whole, especially Nongbaek was markedly higher than the other two. The absorption rate of Ca, Mg and Fe was also equally high in all varieties under low temperature and Nongbaek showed a more absorptive tendency in the absorption amount under low temperature.

• 한국약용작물학회지
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• 제20권3호
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• pp.184-189
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• 2012

This study was carried out to have the basic and applied informations relating to increase the productivity and quality of ginseng. 2 years-old ginseng was cultivated under hydroponic culture with the controlled environment conditions in a greenhouse. Major growth characters and yields were investigated with two different temperatures and several growth stages. The plant height and stem diameter were higher at low temperature than those at high temperature. They were not clearly different with six different growth stages. The root length was not clearly different between two temperatures; however it was continuously grown from June until August. The root diameter was higher at low temperature than that at high temperature. It was rapidly increased from June until August. The length, width, and area of leaf were higher at low temperature than those at high temperature. The fresh and dry weights of different plant tissues were also heavier at low temperature than those at high temperature. The moisture content of ginseng root was continuously decreased from June until August. The yield of ginseng was higher at low temperature compared to that at high temperature. The cultivating conditions in hydroponic culture of ginseng, especially temperature, would be an important factor to have better growth and production.

• 한국재료학회지
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• 제25권11호
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• pp.583-589
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• 2015

This paper presents a study on the room- and low-temperature impact toughness of hypoeutectoid steels with ferrite-pearlite structures. Six kinds of hypoeutectoid steel specimens were fabricated by varying the carbon content and austenitizing temperature to investigate the effect of microstructural factors such as pearlite volume fraction, interlamellar spacing, and cementite thickness on the impact toughness. The pearlite volume fraction usually increased with increasing carbon content and austenitizing temperature, while the pearlite interlamellar spacing and cementite thickness mostly decreased with increasing carbon content and austenitizing temperature. The 30C steel with medium pearlite volume fraction and higher manganese content, on the other hand, even though it had a higher volume fraction of pearlite than did the 20C steel, showed a better low-temperature toughness due to its having the lowest ductile-brittle transition temperature. This is because various microstructural factors in addition to the pearlite volume fraction largely affect the ductile-brittle transition temperature and low-temperature toughness of hypoeutectoid steels with ferrite-pearlite structure. In order to improve the room- and low-temperature impact toughness of hypoeutectoid steels with different ferrite-pearlite structures, therefore, more systematic studies are required to understand the effects of various microstructural factors on impact toughness, with a viewpoint of ductile-brittle transition temperature.

• 터널과지하공간
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• 제7권2호
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• pp.91-99
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• 1997

To stabilize the energy price, the more storage facilities of energy are required and among the storage methods of LPG and LNG, the method of storage at low temperature under normal confining pressure is considered. It is needed to understand the mechanical and thermal characteristics of rock under temperature variation so that the behaviors of rock can be predicted. In this paper, the variation of the rock charateristics of the Hwangdeung granite and the Boryung sandstone is studied at low temperature. The mechanical characteristics of rock under low temperatures are that as temperature decreased, unaxial compression strength and Young's modulus increased for Hwangdeung granite; strength and Young's modulus in wet condition were greater than those in dry condition. In the case of Boryung sandstone, as temperature decreases unaxial compression strength and Young's modulus increase but decrease below -10$0^{\circ}C$ in dry condition and below -16$0^{\circ}C$ in wet condtion. The mechanical characteristics of rock after cooling to previous temperature and thawing are that uniaxial compression strength and Young's modulus decrease as temperature decreases. Uniaxial compression strength and Young's modulus in wet conditon decrease more than those in dry condition. Brazilian tension strength decreases as temperature decreases.

• 대기
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• 제22권2호
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• pp.187-197
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• 2012

This study investigates the relationship between the Korean temperature and the atmospheric circulation such as Arctic Oscillation, Siberian High and Aleutian Low during the winter (December-January) for the period of 1970-2011. It is found that all indices to represent aforementioned circulations are significantly correlated with Korean winter temperature for the period of 1970 - 2011. There are marked contrasts in such relationship, however, before and after the mid-1980s when a significant regime shift of Korean winter temperature occurred. While Korean winter temperature has a close relationship with Arctic Oscillation after the mid-1980s, its relationship with Siberian High and Aleutian Low is weakened. The composite analysis between a positive and negative phase of Arctic Oscillation before and after the mid-1980s is conducted to examine a recent strengthening of Arctic Oscillation-Korean winter temperature relationship. It is found that the structural changes of low-level wind and the geopotential height at 500 hPa between the two phases of Arctic Oscillation are more effective to influence Korean winter temperature after the mid-1980s. This may induce a close relationship between the Korean winter temperature variability and Arctic Oscillation after the mid-1980s compared to before the mid-1980s.