• Fire Protection Technology
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• s.56
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• pp.14-19
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• 2014

• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.1 s.53
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• pp.106-114
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• 2009

The steel design based on the width of transverse crack which is the major factor to affect a long-term performance of continuously reinforced concrete pavement was developed. For this study, twenty-one cities of Texas were selected and the temperature data was collected at those locations during the past ten years. From the data, zero-stress temperatures were calculated by the PavePro program and the widths of transverse crack were analyzed by the CRCP program. The variables used to this numerical analysis were slab thickness, coefficient of thermal expansion of concrete, steel ratio, and design temperature. The total of 448 factorial runs were made and the regression analysis was performed using the results. Steel ratios from the regression equations were backcalculated and a steel design table was proposed.

• Journal of Korean Tunnelling and Underground Space Association
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• v.25 no.6
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• pp.509-523
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• 2023

The high-level nuclear waste (HLW) repository is exposed to complex environmental conditions consisting of high temperature, high humidity, and radiation, resulting in structural deterioration. Therefore, structural health monitoring is essential, and piezo sensors are used to detect cracks and estimate strength. However, since the monitoring sensors installed in the disposal tunnel and disposal container cannot be replaced or removed, the quantitative life of the monitoring sensor and its suitability must be assessed. In this study, the life of a piezo sensor for monitoring was assessed using an accelerated life test (ALT). The failure mode and mechanism of the piezo sensor under high temperature conditions were determined, and temperature stress's influence on the piezo sensor's life was analyzed. ALT was conducted on temperature stress and the relationship between temperature stress and piezo sensor life was suggested. The life of the piezo sensor was assessed using the Weibull probability distribution and the Arrhenius acceleration model. The suggested relationship can be used in multiple stress ALT designs for more precise life assessment.

• Korean Journal of Poultry Science
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• v.48 no.4
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• pp.255-265
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• 2021

Global warming and scorching summer seasons affect the growth ability of broilers and animal welfare. In modern broilers, vital organs, such as the heart and lungs, grow disproportionally under intensive selection, making it difficult to adapt to warmer climates. Changes in environmental temperature can affect muscle formation during embryonic development and the early posthatching period. Satellite cells are highly sensitive to heat stress. Heat stress affects the proliferation and differentiation activity of satellite cells and muscle growth and structure. Therefore, thermal manipulation during broiler chick embryogenesis and environmental temperature management at the beginning of hatching are critical for the development and growth of broiler muscles. This review focuses on the thermoregulation mechanism of birds, the muscle development process of broilers, and the function of satellite cells, the relationship between heat stress and muscle development of chicks shortly after hatching, and studies on heat resistance and muscle growth of broilers.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.2
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• pp.348-354
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• 2009

It has analyzed that the device degradation by NBTI (Negative Bias Temperature Instability) stress induced the increase of gate-induced-drain-leakage(GIDL) current for p-MOSFETs. It is shown that the degradation magnitude, as well as its time, temperature, and field dependence, is govern by interface traps density at the silicon/oxide interface. from the relation between the variation of threshold voltage and subthreshold slope, it has been found that the dominant mechanism for device degradation is the interface state generation. From the GIDL measurement results, we confined that the EHP generation in interface state due to NBTI stress led to the increase of GIDL current. Therefore, one should take care of the increased GIDL current after NBTI stress in the ultra-thin gate oxide device. Also, the simultaneous consideration of reliability characteristics and dc device performance is highly necessary in the stress engineering of nanoscale CMOSFETs.

• Korean Journal of Agricultural and Forest Meteorology
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• v.16 no.4
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• pp.285-296
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• 2014

The impacts of high temperature and drought were studied on the seedlings of three families (superiorgangwon74, intermediate-gangwon77 and inferior-gangwon132) of P. densiflora which had been selected by the based on the growth indexes of 32-year-old. The seedlings were grown in controlled-environment growth chambers with combinations of four temperatures ($-3^{\circ}C$, $0^{\circ}C$, $+3^{\circ}C$ $+6^{\circ}C$; based on the monthly average for 30 years in Korea) and two water conditions (control, drought). The growth performance, photosynthetic parameters and photosynthetic pigment contents were measured at every 30 days under four temperatures and drought condition, and the end of each treatment. The superior family showed higher relative diameter at root collar growth rate and the dry weight than intermediate and inferior family in all treatments. Under elevated temperature and drought condition, growth rate was decreased, and seedlings showed lower growth rate than that of control in three families under low temperature. Photosynthetic rate, stomatal conductance and transpiration rate of three families decreased with the increase of temperature and drought condition, and that of seedlings under low temperature was lower than control. But under elevated temperature and drought condition, water use efficiency increased in three families. Photosynthetic pigment contents of leaves decreased under the increase of temperature and drought condition, but chlorophyll a/b ratio increased with the increase of temperature and drought condition in three families. The superior family showed higher total chlorophyll content than intermediate and inferior family in all treatments. In conclusion, P. densiflora is under changed temperature and drought condition, growth was decreased, seedlings more affected in elevated temperature than that of decreased temperature. The increase in monthly average temperature in Korea of more than $6^{\circ}C$, P. densiflora seedling growth in depending on region may decrease. In this study, the superior family(gangwon74) showed more excellent growth and physiological responses than intermediate (gangwon77) and inferior(gangwon132) family under changes temperature and drought.

• Venture DIGEST
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• no.2 s.127
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• pp.28-29
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• 2009

매일 아침 정해진 시간에 출근해 일하고, 퇴근하는 따분한 일상. 일상의 대부분을 회사생활속에서 스트레스의 해소는 물론, 직원 간의 끈끈한 정이 있는 작은 일탈은 약이 된다. 평생교육 및 성인자격증 콘텐츠를 인터넷 등을 통해 서비스하는 이러닝 산업의 선두주자, (주)유비온의 레저동아리 'COT'는 일탈을 꿈꾸는 유비온들의 휴식공간이 되어주는 사내동호회다.

• Feed Journal
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• v.2 no.9
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• pp.104-107
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• 2004

하절기 사육환경 온도가 상승함에 따라 젖소가 받는 스트레스로 인한 생산성 저하는 저능력우 보다 고능력우에서 증가하게 되는데, 이는 높은 산유량을 유지하는데 필요한 기초 에너지 소모가 증가하여 체온이 증가하기 때문이다. 또한 고능력우들은 높은 산유량을 유지하기 위하여 더 많은 에너지와 영양소를 섭취하여야만 하는데 고온스트레스로 인하여 사료 섭취량이 감소, 에너지 부족현상을 다른 젖소들보다 더 심각하게 겪으므로 대사성 질병 발생이나 번식능력의 저하가 현저히 나타나기 때문이다(외기의 적정온도 : 4~24℃). (중략)

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.229-230
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• 2000

여름철 우리나라 동해안에서 발생하는 냉수대로 인한 급격한 수온변화는 어류의 느린 성장과 질병 발생을 초래하는 요인이 되는 것으로 알려지고 있다. 또한 고수온 기인 여름철에는 발전소의 온배수 배출로 주변수역의 수온이 더욱 상승할 것으로 예상된다. 국외에서는 수온의 급변이 어체의 생리적 변화를 야기시키고 스트레스 요인으로 작용하여, 생체내 대사와 혈액성상의 변화를 일으키는 것으로 연구된 바 있다(Barton and Iwama, 1991). (중략)

• Korean Journal of Ichthyology
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• v.22 no.1
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• pp.1-8
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• 2010

We determined oxidative stress caused by thermal stress in olive flounder Paralichthys olivaceus based on the altered-mRNA expression and enzymatic activity of two key antioxidant enzymes, superoxide dismutase (SOD) and catalase (CAT), along with monitoring of several other biomarkers. When the fish were exposed to acute thermal change (from $20^{\circ}C$ to $25^{\circ}C$ and $30^{\circ}C$), the expression and activity of both enzymes were significantly higher at elevated temperatures ($25^{\circ}C$ and $30^{\circ}C$) than at $20^{\circ}C$. Lipid peroxidation (LPO) was also higher at $25^{\circ}C$ and $30^{\circ}C$ than at $20^{\circ}C$. In addition, the plasma $H_2O_2$ concentration was significantly increased by thermal stress. Furthermore, we investigated changes due to thermal stress by measuring levels of plasma alanine aminotransferase (AlaAT) and aspartate aminotrasferase (AspAT). Both were significantly increased by thermal stress. As an immune indicator, the lysozyme concentration was lower at $30^{\circ}C$ than at $20^{\circ}C$, indicating that thermal stress decreases immune function. Therefore, thermal stress could induce oxidative stress and suppress immune function and can cause physiological stress.