• Title/Summary/Keyword: night temperature

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Structural and temperature coefficient of resistance characteristics of colossal magnetoresistance Mn oxides prepared by RF sputtering

  • Choi, Sun-Gyu;Ha, Tae-Jung;Reddy, A.Sivasankar;Yu, Byoung-Gon;Park, Hyung-Ho
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.11a
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    • pp.361-361
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    • 2007
  • A lot of efforts have been paid to develop infrared imaging systems in last decades. Bolometer has a wide range of applications from military to commercial, such as military night vision, medical imaging system and so on. Bolometer is a resistive sensor that detects temperature changes through resistance change. To improve detecting ability, bolometer should have a good resistive film which has high temperature coefficient of resistance (TCR) value. Colossal magnetoresistance (CMR) $L_{1-x}A_xMnO_3$ (where L and A are trivalent rare-earth ions and divalent alkaline earth ions, respectively.) are received attention to apply bolometer resistive film because it has a high TCR property which was discovered in the metal to semiconductor phase transition temperature region. In this work, CMR films were deposited on various substrates in relative low substrate temperature by RF magnetron sputtering. The influence of deposition parameters such as substrate temperature, gas partial pressure, and so on have been studied. The structural and TCR properties of the films were also investigated for applying to microbolometer.

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Experimental Study of a Low Cost Batch Type Solar Water Heater (저가 Batch형 온수급탕시스템의 실험적 연구)

  • Lee, K.D.;Yoon, H.G.;Kong, Y.H.;Lee, R.J.;Auh, P.C.M.
    • Solar Energy
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    • v.5 no.2
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    • pp.60-69
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    • 1985
  • A low cost batch type solar heaters (capacity 200 litres) comprising horizontal tanks, which performs the dual function of absorbing heat and storing the heated water, have been designed and fabricated for the purpose of side-by-side testing. Experimental results have indicated that the sufficient hot water can be obtained in the early morning if the glazing is aided by a reflector/insulation cover. The water heater with best thermal performance such as type B supplied water at a maximum mean temperature of $46-49^{\circ}C$ in the summer afternoon and the temperature of $36-39^{\circ}C$ can be obtained in the early morning if insulation cover is used during night time. The equation has been developed for the prediction of hourly variation of the water temperature in the tank.

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A Study of Autonomic Responses due to Vehicular Speed Changes (자동차 속도 변화에 따른 자율신경계의 반응 연구)

  • 김철중;민병찬;정순철;김상균;오지영;민병운;김유나
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.22 no.52
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    • pp.203-210
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    • 1999
  • We report on some of the preliminary results of the physiological responses resulting from vehicular speed changes. Healthy human subjects (n=5) were studied for the experiments. We measured the physiological responses of the subjects such as Heart Rate Variability (HRV), Galvanic Skin Response (GSR), and skin temperature for day and night vehicular speed change experiments, respectively. Before and after the tasks, we carried out a self-report for acquiring correlation with experiment results. Mean heart rate variability (HRV) and amplitude of GSR and skin temperature were calculated for 3 minutes duration in each state. The analysis of the physiological measures of ANS activity revealed that vehicle speed change-based affective state evoked arousal response pattern featured by HR acceleration, decrease of skin temperature, and increase of GSR amplitude. The obtained results show that despite some differences observed between each state, overall physiological responses show that the activity of the sympathetic nervous system increases as a result of the increase of speed.

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A Study on Daily Cooling Load Forecast Using Fuzzy Logic (퍼지 논리를 이용한 일일 냉방부하 예측에 관한 연구)

  • 신관우;이윤섭
    • Journal of Institute of Control, Robotics and Systems
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    • v.8 no.11
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    • pp.948-953
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    • 2002
  • The electric power load during the peak time in summer is strongly affected by cooling load, which decreases the preparation ratio of electricity and brings about the failure in the supply of electricity in the electric power system. The ice-storage system and heat pump system are possible solutions to settle this problem. In this study. the method of estimating temperature and humidity to forecast the cooling load of ice-storage system is suggested, then the method of forecasting the cooling load using fuzzy logic is suggested by simulating that the cooling load is calculated using actual temperature and humidity. The forecast of the temperature, humidity and cooling load are simulated, and it is shown that the forecasted data approach to the actual data. Operating the ice-storage system by the forecast of cooling load with night electric power will improve the ice-storage system efficiency and reduce the peak electric power load during the summer season as a result.

Evaluation of Pasquill Stability Class with Monin-Obukhov Length and Estimation Scheme of Stability Parameter (Pasquill 安定度階級의 評價와 安定度 Parameter 測定方法의 開發)

  • Lee, Chong Bum;Kim, Yong Goog
    • Journal of Korean Society for Atmospheric Environment
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    • v.6 no.2
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    • pp.168-175
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    • 1990
  • Pasquill stability class (PSC) was evaluated with Monin-Obukhov length (L) using the data observed at a height of 213m meteorological tower in Tsukuba, Japan. PSC was determined with wind speed and insolation (net radiation at night), and L was calculated with the heat flux and the friction velocity obtained at 25m by the eddy correlation method. To evaluate PSC with L, for every class of Pasquill stability (from A to F class), percentiles and median of L were used. Results show that for every class of Pasquill stability, L varies so widely that PSC does not adequately represent the atmospheric stability conditions. The scheme which estimates L using air temperature at two levels and wind speed at single level was developed. Comparison between estimated L by the scheme and observed L reveals that the scheme is better than PSC. Furthermore, the scheme is more advantageous than PSC because it uses air temperature at two levels instead of insolation which is more difficult to observe in the field than air temperature.

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Effects of Different Day / Night Temperature Regimes on Growth and Clove Development in Cool-type Garlic (Allium sativum L.) (한지형 마늘의 생육 및 인편 발달에 미치는 주야간 온도의 영향)

  • Oh, Soonja;Moon, Kyung Hwan;Koh, Seok Chan
    • Horticultural Science & Technology
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    • v.35 no.1
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    • pp.1-10
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    • 2017
  • We investigated growth, clove development, and photosystem II activity in garlic (Allium sativum L.) grown under different day/night temperature regimes using Soil-Plant-Atmosphere - Research (SPAR) chambers to determine the optimum cultivation temperature and to assess the impact of temperature stress on garlic. In the early stages of growth, plant growth increased markedly with temperature. At harvest time, however, the pseudostem diameter decreased significantly under a relatively low day/night temperature range ($14/10-17/12^{\circ}C$), suggesting that these temperature conditions favor regular bulb growth. At harvest time, the bulb diameter and height were great at $14/10-23/18^{\circ}C$, whereas the bulb fresh weight and number of cloves per bulb were greatest at $17/12-20/15^{\circ}C$. However, the number of regularly developed cloves per bulb was highest at the relatively low temperature range of $14/10-17/12^{\circ}C$, as were the clove length and fresh weight. The photochemical efficiency ($F_v/F_m$) and potential photochemical efficiency ($F_v/F_o$) of photosystem II in the leaves of garlic plants were higher at $14/10-20/15^{\circ}C$ and lower at temperatures below $14/10^{\circ}C$ or above $20/15^{\circ}C$, implying that the $14/10-20/15^{\circ}C$ temperature range is favorable, whereas temperatures outside this range are stressful for garlic growth. Furthermore, at temperatures above $20/15^{\circ}C$, secondary growth of garlic, defined as lateral bud differentiation into secondary plants, continuous growth of the cloves of the primary plants, or the growth of bulbil buds into secondary plants, was enhanced. Therefore, to achieve commercial production of fresh scapes and bulbs of garlic, it may be better to grow garlic at relatively low temperature ranges of $14/10-17/12^{\circ}C$.

Thermal Characteristics of Nutrient Solution and Root Media in Recycled Soilless Culture Systems (순환식 무토양재배시스템의 양액 및 배지의 온도변화 특성)

  • Son, Jung-Eek;Park, Jong-Seok
    • Journal of Bio-Environment Control
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    • v.7 no.1
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    • pp.71-77
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    • 1998
  • The root-zone environment is an important factor to the plant growth and it is closely related to the thermal characteristics of the root media. In this study thermal characteristics of root media with ambient environmental conditions were analyzed. The temperatures of nutrient solution as well as inside air of culture bed were measured in Nutrient Film Technique(NFT) and Deep Flow Technique(DFT) systems, and also the temperatures of root media measured in aggregate culture systems , The temperature of nutrient solution of NFT system with as low as 3$\ell$/min of flow rate was 3$^{\circ}C$ higher than that with 5 $\ell$/min of flow rate in the daytime, and the temperature of inside air was 2$^{\circ}C$ higher at night. And the temperature of nutrient solution of DFT system with as low as 0.8 cm of water level was 1-2$^{\circ}C$ higher than that with 1 8 cm in the daytime, and the temperature of inside air was almost same at night. The root-zone temperatures in the perlite and rockwool granulate systems with film mulching were 3$^{\circ}C$ higher than those without film mulching in the daytime. However, the rockwool slab system with film mulching showed the same trend as rockwool granulate system, but relatively higher temperature than any other medium because of the exposure of media surface to the ambient air. Additionally the temperature below the plant was measured 3$^{\circ}C$ lower than that between plants.

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Preference and Competition for Shelters at Day and Night between Adult and Juvenile Schlegel's Japanese Gecko (Gekko japonicus) in an Indoor Vivarium (실내 사육장에서 도마뱀부치(Gekkojaponicus) 성체와 유체의 주야간 은신처 선호와 경쟁)

  • Park, Il-Kook;Kim, Dae-In;Jang, Se-Yoon;Kim, Do-Yeon;Choi, Woo-Jin;Kim, Jong-Sun;Koo, Kyo-Soung;Park, Daesik
    • Korean Journal of Environment and Ecology
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    • v.32 no.4
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    • pp.373-380
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    • 2018
  • We examined activities of adult (n=9, 3 females and 6 males) and juvenile (n=4) Schlegel's Japanese gecko (Gekko japonicus) in an indoor vivarium for 47 days to study the preference and competition for shelters at day and night. The result showed the strong correlation between the temperature inside the shelter and the body temperature of Schlegel's Japanese gecko and more individuals observed outside the shelters at nighttime than daytime. Both adults and juveniles showed a preference for certain shelters. The adults preferred the warmer shelters in the daytime while the juveniles preferred the same shelter in both daytime and nighttime. Both adults and juveniles observed outside the shelter at the nighttime had higher body temperature than those found inside. In the daytime, the body temperature of adults was higher than that of juveniles, but there was no significant difference in the nighttime. The results imply that G. japonicus, which is the nocturnal lizard, prefers the shelters with higher temperature and that there is the competition for shelters between adults and juveniles. This study provides the reference data on the relationships between the body temperature and the activities of G. japonicus.

Effects of Temperature and Dormancy Breaking on Germination of Newly Developed Rice Varieties (온도 및 휴면타파가 수도신품종의 발아에 미치는 영향)

  • ;Hyun-Ok Choi;Jong-Hoon Lee;Moon-Hee Lee
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.22 no.2
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    • pp.18-22
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    • 1977
  • Germination ability of a japonica and 15 indica$\times$japonica varieties was tested at day/night tempuratures of 25/2$0^{\circ}C$ and 12/12$^{\circ}C$. Germination ability of a japonica variety, "Jinheung" and two indican$\times$japonica varieties. "Suweon #251" and "Suweon #278" was greater than that of other indica$\times$japonica varieties tested. Germination pattern of varieties was made into 4 groups.ieties was made into 4 groups.

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