• Korean Journal of Materials Research
• /
• v.24 no.11
• /
• pp.625-631
• /
• 2014

To investigate the deformation properties of TiC-(5-20) mol% Mo solid solution single crystals at high temperature by compression testing, single crystals of various compositions were grown by the radio frequency floating zone technique and were deformed by compression at temperature from 1250K to 2270K at strain rates from $5.1{\times}10^{-5}$ to $5.9{\times}10^{-3}/s$. The plastic flow property of solid solution single crystals was found to be clearly different among a three-temperature range (low, intermediate and high temperature ranges) whose boundaries were dependent on the strain rate. From the observed property, we conclude that the deformation in the low temperature range is controlled by the Peierls mechanism, in the intermediate temperature range by the dynamic strain aging and in the high temperature range by the solute atmosphere dragging mechanism. The work softening tends to become less evident with an increasing experimental temperature and with a decreasing strain rate. The temperature and strain rate dependence of the critical resolved shear stress is the strongest in the high temperature range. The curves are divided into three parts with different slopes by a transition temperature. The critical resolved shear stress (${\tau}_{0.2}$) at the high temperature range showed that Mo content dependence of ${\tau}_{0.2}$ with temperature and the dependence is very marked at lower temperature. In the higher temperature range, ${\tau}_{0.2}$ increases monotonously with an increasing Mo content.

• Journal of Environmental Science International
• /
• v.16 no.8
• /
• pp.897-906
• /
• 2007

Effect of seawater temperature (temperature) on the production of anchovy, Engraulis japonica and laver, Porphyra tenera Kjellman, were investigated in the eastern part of South Sea of Korea (ESS). Bimonthly temperature data (Feb., Apr., Jun., Aug., Oct., Dec.) from 1980 to 2002 were collected from Korean Oceanographic Data Center (KODC) and monthly anchovy catch and laver production from 1980 to 2002 were used from published sources by the Ministry of Maritime Affairs & Fisheries, Korea. Effects of temperature on the two organisms were examined in four cases. In case of lower anchovy catch and higher laver production (1993), temperature during main spawning season of anchovy was about $0.2-0.6^{\circ}C$ lower than normal condition, and temperature during seed collecting season of laver in Namhaedo, Kojedo went down below $22.0^{\circ}C$. In case of higher anchovy catch and higher laver production (1995), optimum temperature for catch was formed in main fishing ground, temperature for seed collection was lower than $22.0^{\circ}C$, In case of lower anchovy catch and lower laver production (1996), temperature for spawning and catch was about $0.6-1.6^{\circ}C$ lower than normal condition, and temperature during seed collection in nursery was about $0.5-1.0^{\circ}C$ higher than optimum temperature for seed collection. In case of higher anchovy catch and lower laver production (1998), temperature during main fishing and spawning season was about $1.0-1.8^{\circ}C$ higher than normal condition, and temperature during laver seed collection in nursery was $1.5^{\circ}C$ higher than optimum temperature for seed collection.

• Journal of Biosystems Engineering
• /
• v.39 no.4
• /
• pp.336-344
• /
• 2014

Purpose: In this study, the effect of milling on paddy rice stored at low temperature, the changes in grain temperature of bulk storage bags exposed at room temperature, the post-milling water content of paddy rice, the whiteness of rice, and the rate of pest incidence were investigated and data were analyzed. Methods: Changes in temperature inside the bulk storage bags kept at low temperature and grain temperature after exposure to room temperature were measured. Experiments were conducted for identifying the reasons of post-milling quality changes in paddy rice stored at low temperature. Results: It was determined that a short-term increase of water content in paddy rice was directly related to surface condensation, and that rice should be milled at least 72 h after removal from low-temperature storage, in order to completely eliminate surface condensation of paddy rice kept in bulk storage bags. It was observed that post-milling quality of rice changed, but water content was maintained at high levels for more than 18 d in rice that was milled when condensation occurred, regardless of paper or vinyl packaging. Rice whiteness rapidly decreased in rice that was milled when condensation occurred, regardless of packaging, while rice that was milled 72 h or more after removal from low temperature storage did not show any significant changes in whiteness. No pest incidence was observed up to 12 d after removal from low temperature storage, regardless of packaging. Starting at 18 d, after removal from low temperature storage, rice that was milled when condensation occurred, was affected by pests, while 24 d after removal from low temperature storage, all portions of rice were affected by pests. Conclusions: Our results suggest that changes in post-milling quality of rice could be significantly reduced by exposing paddy rice to room temperature for at least 72 h before milling, in order to allow the increase of grain temperature and prevent surface condensation.

• Journal of the Korean Institute of Rural Architecture
• /
• v.20 no.2
• /
• pp.29-36
• /
• 2018

Even in modern times, we are accustomed to the lifestyle of floor heating system in which the floor is heated for warmth like Ondol, which is the traditional Korean heating system. So, this study was designed to understand the preferred floor temperature through the questionnaires targeting the local residents living in K region. This study would also find out the floor temperature which is preferred by young people and old people through the experiments. The findings are as follows; (1) the old people do not prefer the temperature higher than young people do. It was found that the old people prefer the floor temperature of $40^{\circ}C$ under the air temperature of $20^{\circ}C$ or the floor temperature of $41^{\circ}C$ under the air temperature of $20^{\circ}C$. (2) Both young people and old people tend to like the average skin temperature of $35.5^{\circ}C$. The skin temperature which both young and old people like was $35.2^{\circ}C$ under the air temperature of $24^{\circ}C$ and the skin temperature preferred by young people was $0.4^{\circ}C$ higher than that preferred by under the air temperature of $20^{\circ}C$ (p<0.01). (3) It was found in the questionnaires that the young people prefer the higher floor temperature in terms of age and that the people who get older in their 50s or higher tend to prefer the lower temperature.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.27 no.3
• /
• pp.137-145
• /
• 2015

In this study, the actual energy consumption of the secondary side of District Heating System (DHS) with different hot water supply temperature control methods are compared. Three methods are Set-point Control, Outdoor Temperature Reset Control and Outdoor Temperature Prediction Control. While Outdoor Temperature Reset Control has been widely used for energy savings of the secondary side of the system, the results show that Outdoor Temperature Prediction Control method saves more energy. In general, Outdoor Temperature Prediction Control method lowers the supply temperature of hot water, and it reduces standby losses and increases overall heat transfer value of heated spaces due to more flow into the space. During actual energy consumption monitoring, Outdoor Temperature Prediction Control method saves about 7.1% in comparison to Outdoor Temperature Reset Control method and about 15.7% in comparison to Set-point Control method. Also, it is found that at when partial load condition, such as daytime, the fluctuation of hot water supply temperature with Set-point Control is more severe than Outdoor Temperature Prediction Control. Therefore, it proves that Outdoor Temperature Prediction Control is more stable even at the partial load conditions.

• Korean Journal of Agricultural Science
• /
• v.35 no.1
• /
• pp.1-9
• /
• 2008

There were four types of Doenjang fermentation as following conditions for investigation ; 1) low temperature fermentation at $13^{\circ}C$ for 180 days, 2) low temperature at $13^{\circ}C$ for 7 days to room temperature at $30^{\circ}C$ for 10 days, to low temperature at $13^{\circ}C$ for 163 days, and for 173 days, 3) low temperature at $13^{\circ}C$ 7 days to room temperature at $30^{\circ}C$, 4) room temperature at $30^{\circ}C$ for 180 days. There were no changes of moisture, NaCl and total nitrogen content during fermentation period of four types conditions, but pH and amino type nitrogen decreased in room temperature at $30^{\circ}C$ for 180 days. It required 3 times more fermentation period until same quantity of the amino type nitrogen. The low temperature fermentation sample was lower than room temperature fermentation sample in pH and amino type nitrogen. The yeast decreased in low temperature fermentation sample taken 15 to 30 days longer than room temperature sample. The yeast is increased up to 30 days, and decreased little by little. After 60 days, it remained a few without effectiveness on the Doenjang quality. The low temperature fermentation sample showed brighter than room temperature fermentation sample. Different fermentation condition affected Doenjnag quality, especially, low temperature fermentation sample showed bright color in Doenjnag. So low temperature fermentation must be expected as good method for getting high quality Doenjnag.

• The Korean Journal of Community Living Science
• /
• v.22 no.3
• /
• pp.485-491
• /
• 2011

This study was to present the preferred and the suggested indoor temperature of college students in winter based on their body composition. A total of 14 subjects(6 males and 8 females) participated in this study. They sat in a climatic chamber controlled at $24^{\circ}C$ wearing experimental garments(0.7clo). The air temperature decreased $1^{\circ}C$ every 15 minutes until it reached $19^{\circ}C$. After the stepwise temperature change, subjects were asked to select a comfortable air temperature by dialing the temperature control switch inside the chamber. The preferred temperature was determined when subjects did not change the air temperature for 10 minutes. The measurements were oxygen consumption, rectal temperature, skin temperature, and subjective sensation. Main results are as follows. In a mild cold condition, females demonstrated lower oxygen consumption and mean skin temperature than males while keeping a constant rectal temperature. Females increased rectal temperature and decreased mean skin temperature greater than males from $24^{\circ}C$ to $19^{\circ}C$. Males showed larger oxygen consumption increase than females. It appears that the thermo-physiological responses in a mild cold condition might be different between males and females. The preferred winter indoor temperature was $22.3^{\circ}C$ for males and $23.4^{\circ}C$ for females, and the suggested temperature was $21^{\circ}C$ for males and $23^{\circ}C$ for females.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2022.10a
• /
• pp.168-168
• /
• 2022

According to the 5th Climate Change Report, global average temperature in 2081~2100 will increase 1.8℃ based on RCP 4.5 and 3.7℃ based on RCP 8.5 from the current climate value (IPCC Working Group I AR5). As temperature is expected to increase due to global warming and the intensity and frequency of rainfall are expected to increase, damage to crops is expected, and countermeasures must be taken. This study intends to evaluate rice growth in terms of nitrogen utilization efficiency according to future climate change conditions. In this experiment, Oryza sativa cv. Shindongjin were planted at the SPAR facility of the NICS in Wanju-gun, Jeollabuk-do on June 10, and were planted and grown according to the standard cultivation method. Cultivation conditions are high temperature, high CO₂ (current temperature+4.7℃·CO₂ 800ppm), high temperature (current temperature+4.7℃·CO₂ 400ppm), current climate (current tempreture·CO₂ 400 ppm). Nitrogen was varied as 0, 9, 18 kg/10a. The N content and C/N ratio of all rice leaves, stems, and seeds increased at high temperature, and the N content and C/N ratio decreased under high temperature and high CO₂ conditions com pared to high temperature. Compared to the current climate, NUE increases by about 8% under high temperature and high CO₂ conditions and by about 2% under high temperature conditions. This seems to be because the increase in temperature and CO₂ induced the increase in biomass. ANUE related to yield decreased by about 70% compared to the current climate under high temperature conditions, and decreased by about 45% at high temperature and high CO₂, showing a tendency to decrease compared to high temperature. This appears to be due to reduced fertility and poor ripening due to high temperature stress. However, as the nitrogen increased, the number of ears and the number of grains increased, slightly offsetting the production reduction factor.

• Sleep Medicine and Psychophysiology
• /
• v.23 no.2
• /
• pp.47-52
• /
• 2016

Changes in core body temperature are closely related to initiation and maintenance of sleep, and are influenced by various factors such as air temperature, room temperature, clothing, human activities, and medications. These factors are closely related to sleep fragments, insomnia and other sleep disorders. Understanding the effect of the temperature related to human surroundings on the core body temperature and sleep, will be useful for understanding the physiology of sleep and to treat sleep disorders.

• Tribology and Lubricants
• /
• v.9 no.1
• /
• pp.16-21
• /
• 1993

A method has been developed to measure the surface temperature in a sliding tribosystem. The determination of the surface temperature was inferred from the temperature of hot spots which were generated by frictional heat. The temperature of hot spots was determined by regressing those digitized data on Gecim-Winer's theoretical model. The experimental results are discussed considering the important factors such as PV and frictional heat. The surface temperature rise is related to the thermal conductivity in low PV range. As PV increases, it reaches nearly constant value called the critical temperature.