• Composites Research
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• v.35 no.6
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• pp.425-430
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• 2022

In this study, the mechanical properties of the pressure vessel composite exposed to the thermal environment were evaluated to establish the standard for high temperature static pressure test of the pressure vessel for hydrogen bus. As the tensile strength of the composite material approaches the glass transition temperature of the epoxy resin, the strength decreases due to the deterioration of the epoxy resin. In addition, it was confirmed that the tensile strength increased again due to the post-curing of the epoxy resin during long-term exposure. Therefore, the accelerated stress rupture test conditions of the pressure vessel for the hydrogen bus should be set based on the epoxy resin properties of the carbon fiber composite material.

• Journal of Mushroom
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• v.16 no.2
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• pp.79-85
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• 2018

This study was carried out to separately assess the production of post-culture, germinating, growing, and resting stages of Lentinula edodes grown in a smart cultivation facility based on ICT technology. The cultivation environment of the greenhouse facility was controlled to remain at different set points throughout a range of high ambient temperatures. Production of Sanjo-701-ho, which is a typical summer cultivar, and the new cultivar Sanjo-701-ho were tested in this ICT-based smart cultivation system. Sanjo-701-ho produced 353.7 g/bag of mushrooms from June to October, while Sanjo-701-ho produced 270.4 g/bag. These production amounts were stable over the high-temperature range of $20-35^{\circ}C$.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1995.10a
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• pp.71-73
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• 1995

시금치는 명아주과로서 고온 장일 조건하에서 추대가 촉진되고 고온에는 극히 생육이 약하여 $25^{\circ}C$ 이상이 되면 생육장해나 병충해가 만연한다. 이러한 생육특성으로 고온, 건조, 장일과 같은 불량 환경조건이 가중되는 여름철 수확재배는 대단히 어렵다. 따라서 매년 여름철에 입하되는 양은 절대적으로 부족하며 그 중에서도 특히 7월-9월에는 대단히 고가이다. 본 실험은 여름철 평지에서도 양질의 시금치를 대량생산할 수 있는 기술 확립을 위한 연구로 여름철 온실의 재배시기별 차광효과를 구명코자 실시하였다. (중략)

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.232-235
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• 2017

Scramjet combustor materials are exposed at ultra high temperature over 2000K and severe erosion environment. Inconel alloys are usually applied for combustor material however its mechanical properties are decreased beyond temperature of 1000K so that is impossible for long term operation and reuse. In this study, fiber reinforced ceramic material was used as scramjet combustor material and its feasibility studied. To increase combustion efficiency, regenerative combustor system developed and channel fabrication in composite material also studied.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.21 no.1
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• pp.125-131
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• 1976

To study the effects of temperature, day length, and various plant growth regulator treatments on the tuber formation of Irish cobbler, this experiment was carried out with 2 combinations of day-length and temperature and 11 kinds of growth regulator, including GA, and their combinations. For the tuber formation, low temperature-short day condition played decisive role, and exceeded the effects of growth regulators. 4 times foliar application of 10 ppm GA resulted marked elongation of stolon but did not inhibit the tuber formation even under high temperature longday condition.

• Journal of the Korea Concrete Institute
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• v.26 no.1
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• pp.71-78
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• 2014

The long term integrity of concrete cask is very important for spent nuclear fuel dry storage system. However, there are serious concerns about early deterioration of concrete cask from creaking and corrosion of reinforcing steel by chloride ion because the cask is usually located in seaside, expecially by combined deterioration such as chloride ion and heat, carbonation. This study is to investigate the relation between temperature and chloride ion diffusion of concrete. Immersion tests using 3.5% NaCl solution that were controlled in four level of temperature, i.e. 20, 40, 65, and $90^{\circ}C$, were conducted for four months. The chloride ion diffusion coefficient of concrete was predicted based on the results of profiles of Cl- ion concentration with the depth direction of concrete specimens using the method of potentiometric titration by $AgNO_3$. Test results indicate that the diffusion coefficient of chloride ion increases remarkably with increasing temperature, and there was a linear relation between the natural logarithm values of the diffusion coefficients and the reciprocal of the temperature from the Arrhenius plots. Activation energy of concrete in this study was about 46.6 (W/C = 40%), 41.7 (W/C = 50%), 30.7 (W/C = 60%) kJ/mol under a temperature of up to $90^{\circ}C$, and concrete with lower water-cement ratio has a tendency towards having higher temperature dependency.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2020.10a
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• pp.79-79
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• 2020

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2020.10a
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• pp.80-80
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• 2020

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2017.10a
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• pp.45-45
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• 2017

• Journal of the Korean Data and Information Science Society
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• v.28 no.6
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• pp.1437-1445
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• 2017

This paper suggests a temperature guidance which must be addressed in the preparation of specifications for military equipment used in ocean/coastal environment of the Korean peninsula. It would often be costly to design materiel to operate under the most extreme environmental conditions ever recorded. Therefore, military planners usually accept equipments designed to operate under environmental stresses for all the time except a certain small percentage of the time. In this study, an 1-percent frequency of occurrence is recommended. Pohang and Shineiju are chosen to represent the hottest and coldest regions, respectively, based on surface weather observations among 28 costal regions from 1904 to 2015. The 1st and 99th percentile temperatures for Pohang and Shineiju are $37.7^{\circ}C$ and $-23.7^{\circ}C$, respectively. Diurnal cycles, including solar radiation, relative humidity and wind-speed are also provided.