• Environmental engineer
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• s.92
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• pp.14-19
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• 1994

• Proceedings of the Korean Environmental Sciences Society Conference
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• 1993.04a
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• pp.5-5
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• 1993

• Korean Journal of Construction Engineering and Management
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• v.20 no.1
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• pp.133-140
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• 2019

The concrete mix should be designed and produced to reflect the specific site conditions during concrete placement. That is, the concrete mix design should be planned considering temperatures, work environments, pouring methods, etc. The objective of this research is to understand the external factors of curing temperature and delay time that influence concrete strengths during pouring work, and provide concrete mix design that can be most robust to the effects of external factors. The Taguchi's robust method is used in preparing the concrete mix design to achieve the research objective. In a case study, an indoor concrete test was performed to find the optimal combination of concrete mixes with external factors of curing temperature and delay time. Concrete test cylinders were made to test concrete strengths given different external factors. The study results showed that the optimal performance of concrete strength can be achieved by applying the robust method when preparing a concrete mix design.

• Korean Journal of Environment and Ecology
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• v.37 no.3
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• pp.192-197
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• 2023

This study was conducted to determine whether the difference in egg hatching temperature of Korea Reeves' turtle (Mauremys reevesii) at the artificial nursery of Seoul National Grand Park affects the incubation period and growth. A total of 201 eggs were incubated at 26 ℃ (n=89), 28 ℃ (n=75) and 32 ℃ (n=37). The incubation period of eggs showed significant differences according to the hatching temperature. In this study, the higher the hatching temperature, the higher the hatching rate. The incubation period of the eggs hatched at 26 ℃, 28 ℃ and 32 ℃ was 66.1 (±4.0, n = 52) days, 65.3 (±3.3, n = 44) days and 58.8 (±7.7, n = 31) days, respectively. Eggs incubated at 32 ℃ (83.8%) had a higher hatching success than those at 26 ℃ (58.4%) and 28 ℃ (58.7%). The body mass of 14-day-old hatchlings incubated at 32 ℃ was greater than those incubated at 26 ℃ and 28 ℃. However, there was no significant difference in the mean body mass of 180 and 270-day-old turtles hatched at these different temperatures. This study showed that the hatching temperature significantly affected the incubation period and body mass in the early life of the Korea Reeves' turtle (M. reevesii).

• 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.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.4C
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• pp.163-174
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• 2009

Mechanical device using the load cell or strain gage sensor can be influenced by tempearute changes because temperature change can cause a shift in the load cell or straing gage output at zero loading. In this paper, micro cone penetrometers with 1~7mm in diameter, are developed by using an optical fiber sensor (FBG: Fiber Bragg Grating) to compensate the continous temperature change during cone penetration test. Note the temperature compensated method using optical fiber sensor which has hair-size in diameter, and is not affected by environmental conditions because the measured data is the wavelength shifting of the light instead of the intensity of the electric voltage. Temperature effect test shows that the output voltage of strain gage changes and increases with an increase in the temperature. A developed FBG cone penetrometer, however, achieves excellent temperature compensation during penetration, and produces continuous change of underground temperature. In addition, the temperature compensated FBG cone shows the excellent sensitivity and detects the interface of the layered soils with higher resolution. This study demonstrates that the fiber optic sensor renders the possibility of the ultra small size cone and the new fiber optic cone may produce more reliable temperature compensated tip resistance.

• Journal of Energy Engineering
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• v.8 no.1
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• pp.14-22
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• 1999

본 연구는 일반적으로 소·중용량의 냉동·공조기에 많이 사용되고 있는 플레이트 핀 코일형 공냉응축기를 대상으로 수치해석에 의해 응축기의 특성을 파악하였다. 해석에서는 응축기를 과열증기영역, 2상영역 및 과냉각액영역으로 구분하여 공냉 응축기의 성능에 큰 영향을 미치고 있는 공기온도, 공기측열전달률, 입구 냉매온도, 응축온도 및 질량유량 등을 파라메터로하여 이들의 상호관계와 이들이 응축완료점까지의 거리 및 방열량 등에 미치는 영향을 파악하였다. 해석결과로는 해석모델로부터 각 영역의 냉매 상태량, 온도분포 및 열전달률을 구할 수 있었고, 일반적으로 응축기의 성능에 많은 영향을 미치는 각종 파라메터들을 중심으로 광범위한 동작조건에서 이들의 상관관계 및 특성을 파악하므로서 응축기 설계를 위한 기초 자료 및 설치장소나 주위환경 등에 따라 서로간에 다양한 영향을 미치는 실제장치의 동적특성 해석을 위한 자료를 얻을 수 있었다.

• Proceedings of the Optical Society of Korea Conference
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• 2003.07a
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• pp.138-139
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• 2003

반사경을 지지하는 데에 있어서의 기계적, 열적 변형이 광학 부품에 미치는 영향을 최소화 하도록 광학 요소를 이러한 영향으로부터 차단하는 기계 장치를 플렉셔(flexure)라고 한다. 기계적 영향은 중력, 관성, 진동에 의한 하중 및 조립 시의 오차에 의한 응력 등에 의해 발생하는 변형을 말한다. 또한 열적 영향은 열적 평형 상태와 과도 상태 하에서 주위 환경의 온도변화에 의한 변형을 말한다. 예를 들어 작은 열팽창 계수를 가진 반사경 또는 렌즈와 큰 열팽창 계수를 갖는 지지구조가 어떤 온도 하에서 조립된 후 처음 온도와 다른 온도에 놓이는 경우를 생각해 보자. (중략)

• Journal of the Korean GEO-environmental Society
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• v.13 no.11
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• pp.51-60
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• 2012

In order to characterize the shear strength of the frozen sand for foundation design in cold region and prediction of adfreeze bond strength, many researchers developed test techniques and carried out many tests to analyze shear strength properties of the frozen sand for half a century. However, many studies for shear strength properties of the frozen sand have been carried out with limited circumstances, even though shear strength of the froze sand can be affected by various influence factors such as soil type, temperature conditions, and magnitude of normal stress. In this study, direct shear test equipment was used to analyze the shear strength characteristics of the frozen sand. Direct shear test equipment was designed for cold weather, and the direct shear tests were carried out inside of large-scaled low temperature chamber. Three soil types-two uniform sands and one well graded soil were used to analyze the shear strength of the frozen sand with three different temperature conditions and three different vertical confining pressures. In this research, a series of direct shear tests for shear strength of the frozen sand have been conducted to demonstrate the efficiency of effectiveness of the test equipment and low temperature chamber. This research also showed that shear strength of the froze sand increased with decreasing temperature condition, but the influence of vertical confining pressure was insignificant to the shear strength of the frozen sand.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2005.05a
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• pp.249-251
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• 2005

SA와 온도가 애기장대의 안토시아닌 생성에 미치는 영향을 조사하기 위하여 여러 농도의 SA와 다양한 온도를 처리하여 시간적 경과에 따른 안토시아닌 함량변화와 PAL 환성을 조사하였다. 10 ${\mu}$M 이하의 SA 처리구에서는 안토시아닌 함량에 있어서 큰 변화가 없었으나 100 ${\mu}$M 이상의 처리구에서는 크게 증가하였다. 25 ${\mu}$M SA처리구에서 안토시아닌 함량이 가장 높았으며 5일째에는 약 3.3배 증가하였다. 그러나 100 ${\mu}$M의 고농도 SA 처리구에서는 감소하는 경향을 나타내었다. PAL 활성은 25 ${\mu}$M SA 처리시 점차 증가하여 3일째에 가장 높은 활성을 보였다가 이후 서서히 감소하였다. 그러나 100 ${\mu}$M 이상의 SA 처리구에서는 PAL활성이 점차 감소하는 경향을 보여 주었다. 온도조건에 따라 안토시아닌 축적은 다소 차이를 보여 주었는데, 10$^{\circ}C$ 및 15$^{\circ}C$ 에서 안토시아닌 생성이 촉진되었으나, 온도가 상승함에 따라 점차 감소되어 30$^{\circ}C$의 고온에서는 현저하게 저하되었다. 따라서 본 연구결과로부터 애기장대의 안토시아닌 축적현상은 SA의 외적 처리와 온도요인에 의해 형성된 스트레스에 반응하여 유도된 것으로 추측되며 일종의 보호기능과 관련이 있음을 시사해 준다.