• 한국세라믹학회지
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• 제46권2호
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• pp.146-154
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• 2009

It is necessary to minimize the thickness of Ni inner electrode layer and to improve the coverage of inner electrode, for the purpose of developing the ultra high-capacity multi layered ceramic capacitor (MLCC). Thus, low temperature sintering of dielectric $BaTiO_3$ ceramic should be precedently investigated. In this work, the relationship between dielectric properties of MLCC and batch condition such as mixing and milling methods was investigated in the $BaTiO_3$(BT)-Dy-Mg-Ba system with borosilicate glass as a sintering agent. In addition, several chip properties of MLCC manufactured by low temperature sintering were compared with conventionally manufactured MLCC. It was found that low temperature sintered MLCC showed better DC-bias property and lower aging rate. It was also confirmed that the thickness of Ni inner electrode layer became thinner and the coverage of inner electrode was improved through low temperature sintering.

• Journal of Pharmaceutical Investigation
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• 제33권1호
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• pp.15-19
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• 2003

The rheological behavior of poloxamer 407 solution as function of concentration and temperature was evaluated by rotational viscometer. The viscosity of poloxamer 407 solution was increased as the concentration of poloxamer 407 and temperature increased. At $4^{\circ}C$, poloxamer 407 solution showed the Newtonian flow characteristics regardless of concentration. Upon increasing temperature the poloxamer solution changed to the pseudoplastic flow pattern. And at gelation temperature, rheological profiles showed the abrupt increase in viscosity. Gelation temperature was decreased as the concentration of poloxamer 407 increased, while it increased as the concentration of poly(ethylene glycol) 4000 increased. Poly(ethylene glycol) might be expected to reduce the driving force for hydrophobic interaction resulting in slow gelation. From the viscoelastic properties of poloxamer gel system, we obtained the storage and loss modulus depending on the shear stress and frequency. And the sol-gel transition temperature was also obtained from the viscoelastic properties of poloxamer 407 gel.

• Journal of Biosystems Engineering
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• 제39권4호
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• pp.336-344
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• 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.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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• pp.433-436
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• 2006

This study is basic experiment for estimating influence of strength by curing temperature of concrete's heat of hydration and estimate relationship of compressive strength development by initial curing temperature factor, and then asume temperature factor which influence compressive strength development and for showing basic document of quality control. According to the result of managerial test pieces by the curing temperature factor high-curing temperature shows high strength on 3 day compare with low curing-temperature, shows higher strength than the piece of high curing temperature.

• International Journal of Industrial Entomology and Biomaterials
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• 제7권2호
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• pp.203-208
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• 2003

Rearing temperature influences food consumption, conversion and cocoon production in silkworm Bombyx mori L. Young age $({1^st}to{3^rd} instar)$ worms of Pure Mysore, a multivoltine were reared at 26, 28, 30 and $32^{\circ}C$ followed by combinations of these temperature levels during late age $({4^th} and {5^th} instar)$. Food consumption, conversion, larval duration and growth for each instar were recorded. The influence of combinations of these temperature levels during rearing on survival and cocoon production was assessed. Food consumption increased with the temperature up to $4^th$ instar and decreased during $5^th$ instar. Temperature beyond $28^{\circ}C$ during young age followed by higher temperature ($30^{\circ}C$ and above) has shown deleterious effect on cocoon production. The paper discusses the rearing performance in relation to food intake and conversion under the tested temperature levels.

• International Journal of Industrial Entomology and Biomaterials
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• 제29권2호
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• pp.153-161
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• 2014

The aim of this study is to investigate the effects of ambient thermal environments on the development of swallowtail butterflies (Sericinus montela Gray). Developmental durations and survival rates of S. montela were examined at two crucial developmental stages, embryonic and larval development, at varying temperatures ranging from $15^{\circ}C$ to $35^{\circ}C$. As expected, our results indicated that increasing temperatures decreased the developmental duration and survival rate of the eggs. However, the larvae and pupae showed maximum survival rates at $20.0^{\circ}C$ and $25.0^{\circ}C$, and the represented durations were similar to those of the eggs. Larval development was stage-specific, revealing that the fourth and fifth instars at the later stages were more susceptible to temperature variation. When considering both parameters, the optimal development of S. montela occurred within the temperature range of $20.0-25.0^{\circ}C$. The lower threshold for the complete development of S. montela from eggs to eclosion of adults was calculated at $10.6^{\circ}C$ by linear regression analysis. The estimated value is similar to that of other endemic insects distributed in temperate climate zones, which indicates that S. montela belongs to a small group of swallowtails adjusted to low ambient temperatures. From the results, we predict that the full development of S. montela could be achieved within the temperature range of $17.5-30.0^{\circ}C$. Embryonic development ceased at both test temperature extremes, and no further larval development proceeded after the third instar at $35.0^{\circ}C$. These results suggest that embryogenesis can be significantly influenced by slight variations in the ambient thermal environment that fall below the optimal range.

• The Plant Pathology Journal
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• 제18권4호
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• pp.199-203
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• 2002

Soft rot occurred severely in onion bulbs stored under low temperature ($5^{\circ}C$) in storage houses at Changyoung, Kyungnam province, Korea in early 2000. Water-soaking and yellowish-brown lesions initially appeared on the outside scales of diseased onion bulbs, gradually progressing into the inside scales. Among the bacterial isolates obtained from the lesions, K-2 isolate was found to be responsible for the disease, which grew at a temperature range of from $0^{\circ}C$ to $36^{\circ}C$ with optimum temperature of $00^{\circ}$-$33^{\circ}C$. However, it showed strong pathogenicity to onion bulbs at $25^{\circ}C$ and $5^{\circ}C$ at 3 days and 2 months, respectively. The bacterium also caused soft rot on potato and showed hypersensitive reactions to tobacco and potato. The causal bacterium of onion soft rot was identified as Pseudomonas marginalis based on morphological, biochemical, and physiological characteristics including LOPAT, Soft rot in onion under low temperature storage caused by P. marginalis has not been previously reported.

• 한국환경과학회지
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• 제18권10호
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• pp.1171-1179
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• 2009

The solitary ascidian, Halocynthia aurantium, which is commonly called the sea peach because of its coloration and general shape, is a valuable organism of benthic marine population in the northern region of the East Sea, Korea. It is seldom found at a depth of less than 10 meters and the sea peach is frequently observed in large populations between 20 and 100 meters. It appears to prefer attachment to vertical rocks faces and artificial cement blocks exposed to the currents. Mass mortality and reduction of resources in sea peach, H. aurantium, were occurred in the benthic area of the northern region of the East Sea because of the rapid fluctuation of environmental factors such as temperature and salinity due to mass rainfall in summer and going up north of a strong warm current in winter. Therefore, we examined the effects of temperature and salinity on embryonic development of fertilized eggs, tadpole larva to metamorphosis, and attachment to siphon development. Laboratory-raised larvae were studied using a two-factorial experimental design with four levels of temperature(8, 12, 16 and $20^{\circ}C$) and four levels of salinity(20, 25, 30 and 34 psu). The ascidian larvae of H. aurantium survived environmental conditions between temperature of $8{\sim}20^{\circ}C$ and salinity of 25~34 psu and exhibited positive growth at $8{\sim}16^{\circ}C$ and 30~34 psu. Fertilized eggs have not developed at lower salinity of 20 psu irrespective of temperature range tested and have showed an abnormal development at the salinity of 25 psu between higher temperatures of 20 and $24^{\circ}C$. This result suggests that temperature increase and salinity reduction depending on environmental fluctuation may have significant impacts on population variation of H. aurantium in the northern region of the East Sea.

• 한국농공학회논문집
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• 제62권5호
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• pp.85-91
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• 2020

In order to calculate the Crop Water Stress Index (CWSI), it is necessary to collect weather data (air temperature, humidity, wind speed and solar radiation) and canopy temperature. However, it is not always available to have necessary data sets for CWSI calculation. Therefore, this study was aimed to develop an easy and simple CWSI equation (CWSI_EE) using only two data, air and canopy temperatures. Infrared sensors and weather sensors were installed on apple and peach trees and nearby a study area and every ten-minute data were collected from June to October in 2018 and 2019, respectively. A relationship between air-canopy temperature difference and CWSI was statistically analyzed and used to develop CWSI_EE using the three dimensional Gaussian model. The performance of CWSI_EE against original CWSI showed R² and NSE to 0.780 and 0.710 for apple trees and R² and NSE to 0.884 and 0.866 for peach trees. This study found that the level of crop water stress could be easily calculated using CWSI_EE with only air and canopy temperature data.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.150-150
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• 2022

Plant reproduction associated with crop yields is highly vulnerable to global climate change components such as high and cold temperatures. The objectives of this study were to determine the effects of season-high exposure to temperature treatments in pollen morphology on Adzuki bean (V. angularis) and Mung bean (V. radiate). V. angularis and V. radiata were treated at high temperatures in the high temperature gradient greenhouse designed to cause temperature deviation. The pollen shapes treated at high temperature were compared by an electron scanning microscope. As a result, it was confirmed that the number of abnormal pollens morphology at high temperature was the least in V. radiata, and V. angularis was vulnerable to high temperatures. Also, it was found that the number of abnormal pollen morphology atT4 (Con +5~6℃) varied according to the cultivars of V. angularis. Therefore, the differences in Vigna species or cultivars with thermo-tolerance in pollen morphology to high temperature are projected to occur in the changeable future climate.