• 한국수산과학회지
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• 제27권3호
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• pp.215-222
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• 1994

본 연구는 강릉지역에 향토식품으로만 명맥을 유지하고 있는 오징어 식해를 제조하여 숙성온도 및 숙성기간을 달리하였을 경우의 여러가지 화학적인 변화를 실험하였으며 그 결과를 요약하면 다음과 같다. 숙성기간동안 일반성분 및 염도의 변화는 거의 없었으며, 단지 조단백은 숙성기간이 증가함에 따라 다소 감소하는 경향을 나타내었다. pH는 $5^{\circ}C$를 제외하고는 숙성기간이 증가함에 따라 감소하였으며 특히 $15^{\circ}C$와 $20^{\circ}C$ 숙성에서는 숙성초기부터 급격하게 감소되었으며, 젓산 생성은 pH 감소와 반비례하여 증가하였다. 총 arginine량은 숙성초기에는 다소 증가하는 경향을 보였으나 전반적으로 변화가 거의 없었다. 아미노태 질소량은 숙성 15일까지는 급격하게 증가하다가 그 후로는 서서히 증가하였다. TMAO 량은 $5^{\circ}C$ 및 $10^{\circ}C$에서는 서서히 감소하였으며 $15^{\circ}C$ 및 $20^{\circ}C$에서는 숙성초기에 급격하게 감소하였다. TMA량은 숙성초기에는 $20^{\circ}C$를 제외한 숙성온도에서는 서서히 증가하다가 20일 이후 감소하는 경향을 보였다. 핵산관련물질은 숙성 초기에만 AMP가 존재하였고 Inosine 및 hypoxanthine 이 핵산관련물질의 대부분을 차지하였다. 이상의 결과를 고려할 때 식해숙성 조건은 15일 정도가 최적이며 저온($5^{\circ}C$ 이하)에서는 조금 더 숙성기간이 길어진다고 생각된다.

• 대한치과기공학회지
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• 제32권4호
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• pp.307-315
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• 2010

Purpose: The purpose of this study was to investigate the change of microstructures and mechanical properties of pure titanium casting specimens as a function of mold temperatures. Methods: The pure titanium castings were fabricated using the centrifugal vacuum casting method with different mold temperatures of $200{\sim}500^{\circ}C$. The resulting castings were characterized by optical microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy and vicker,s hardness tester. Results: In case of the mold temperatures over $400^{\circ}C$, the porosity, surface crack and large grain size were observed in resulting castings. Conclusion: In this work, The most suitable mold temperature in casting of pure titanium was $300^{\circ}C$.

• Steel and Composite Structures
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• 제20권1호
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• pp.185-203
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• 2016

Shear connectors are key components to ensure the efficient composite action and satisfactory transfer of shear forces at the steel-concrete interface in composite beams. Under hazardous circumstances, such as fire in a building, the performance of a composite beam significantly relies on the performance of shear connectors. Studies on the behavior of shear connectors subjected to elevated temperatures performed in the last decade are reviewed in this paper. The experimental testing of push-out specimens, the design approaches provided by researchers and different codes, the major failure modes, and the finite element modeling of shear connectors are highlighted. The critical research review showed that the strength of a shear connector decreases proportionally with the increase in temperature. Compared with the volume of work published on shear connectors at ambient temperatures, a few studies on the behavior of shear connectors under fire have been conducted. Several areas where additional research is needed are also identified in this paper.

• Coupled systems mechanics
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• 제3권1호
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• pp.73-88
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• 2014

The paper deals with a model founded on the physical processes in concrete subject to high temperatures. The model is developed in the framework of continuum damage mechanics and the theory of porous media and is demonstrated on selected structures. The model comprises balance equations for heat transfer, mass transfer of water and vapour, for linear momentum and for reaction. The balance equations are completed by constitutive equations considering the special behaviour of concrete at high temperatures. Furthermore, the limitation and decline of admissible stresses is achieved by using a composed, temperature depending crack surface with a formulation for the damage evolution. Finally, the complete coupled model is applied to several structures and to different concrete in order to determine their influence on the high-temperature-behaviour.

• 한국지열·수열에너지학회논문집
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• 제14권4호
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• pp.13-19
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• 2018

The Effects of hot water supply temperature on indoor thermal characteristics for floor radiant heating system in residential apartment were researched by computer simulation. The parametric study on hot water supply temperatures with different outdoor air temperatures was done with regard to energy performance and control characteristics, respectively. As a result, the maximum overshoot of indoor air temperature and energy consumption were reduced by adjusting the hot water supply temperatures with outdoor air temperatures.

• 한국산학기술학회논문지
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• 제14권2호
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• pp.517-522
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• 2013

아이스크림제조기는 원액통과 냉각통의 증발온도가 $4^{\circ}C$와 $-8^{\circ}C$로 각각 다르므로 다수의 모세관을 이용하는데 이 경우 서로 냉매 유량에 영향을 주므로 냉동사이클 설계가 복잡하다. 본 연구에서는 증발온도가 서로 다른 두개의 증발기(냉장 및 냉동)가 장착된 소프트 아이스크림 제조기의 성능을 해석하였다. 압축기 해석에는 효율모델을 적용하였고, 모세관은 1차원 유동으로 간주하여 해석하였으며, 응축기와 증발기는 UA-LMTD법을 적용하여 해석하였다. 요소부품에서의 엔탈피, 압력 및 질량의 평형을 적용하여 냉동사이클 시뮬레이션 프로그램을 개발하였고 R404A를 사용하는 아이스크림 제조기에 적용한 결과, 냉장과 냉동 증발기의 온도를 $3^{\circ}C$ 이내로 예측하여 측정치와 대체로 일치하였다.

• ALGAE
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• 제39권1호
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• pp.31-41
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• 2024

Acadian marine plant extract powder (AMPEP) and Kelpak are commercial biostimulants derived from brown algae Ascophyllum nodosum. This study was to determine if AMPEP and Kelpak can induce thermal resistance in Pyropia yezoensis. P. yezoensis blades were exposed to different concentrations (control: 0, low: 0.001, high: 1 ppm) of AMPEP and Kelpak at 10℃ for 6 and 7 days, respectively. Those blades were then cultivated in von Stosch enriched seawater medium at different temperatures (10, 15, 20, and 25℃) with 12 : 12 L : D photoperiod and 100 µmol m^-2 s^-1 of photosynthetically active radiation for additional 15 days. Results showed that P. yezoensisreproduced archeospores at 20 and 25℃ at all biostimulant conditions within 15 days. At lower temperatures (10 and 15℃), only AMPEP-treated P. yezoensis reproduced archeospores. P. yezoensis exposed to 1 ppm Kelpak exhibited higher phycoerythrin and phycocyanin contents than control and 0.001 ppm conditions at 15℃. AMPEP-treated conditions showed higher phycoerythrin and phycocyanin contents than control at 10℃. These results suggest that AMPEP and Kelpak may not enhance the thermal resistance of P. yezoensis. However, AMPEP stimulated archeospores release at lower temperatures. The treatment of AMPEP and Kelpak also increased the pigment contents in P. yezoensis. These results suggest that the use of seaweed-derived biostimulants can provide some economic benefits in P. yezoensis aquaculture. The enhancement of archeospores formation by AMPEP at lower temperature may also increase the productivity since Pyropia farming relies on the accumulation of secondary seedings via asexual reproduction.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2005년도 제31회 KOSCO SYMPOSIUM 논문집
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• pp.110-119
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• 2005

The combustion characteristics of binary component single droplets hanging at the tip of a quartz fiber are studied experimentally at different environmental pressures and temperatures under normal gravity. Normal Heptane and Normal Hexadecane are selected as two fuels with high difference in boiling temperatures. A falling electrical furnace in a high pressure vessel has provided high temperature environment. Nitrogen and air have formed the environment to study evaporation and combustion, respectively. The initial diameter of droplet was ranging from 1.1 to 1.3 mm. The evaporation and combustion processes were recorded by a high speed digital camera. Some characteristics of droplet burning under different environment conditions and different droplet composition have been investigated. Microexplosion of droplet take places under atmospheric pressure. Bubble formation and its consequent result, incomplete droplet disintegration which presents in all binary compositions, do not appear at high pressure. The initiation of combustion, always takes place in the bottom of droplet due to buoyancy effect of relatively cold fuel vapor. Also, the burning of binary droplet produces soot when the pressure is high.

• 한국막학회:학술대회논문집
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• 한국막학회 1995년도 제3회 심포지움 (분리막 연구의 최신동향)
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• pp.39-55
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• 1995

Modified polycrylonitrile(PAN) membranes were prepared by emulsion or emulsifier-free emulsion polymerization technique. Separation capacity was determined at several operating temperatures(25, 40, 55 and 70 $^{\circ}$C) to dehydrate 56wt% pyridine aqueous solution through modified PAN membranes having different functional groups. All these PAN-based membranes were selective toward water to different degrees depending on the nature of functional groups present in the membranes. Pervaporation characteristics of PAN-based membranes are so different and classified into three categories depending on the type of the functional groups in PAN copolymers. Among PAN-based membranes, the in-situ complex membranes show the best separation capacity over the operating temperatures.

• 한국지열·수열에너지학회논문집
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• 제15권4호
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• pp.32-38
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• 2019

In this study, the effect of hot water supply flow rates on energy consumption for radiant floor heating system in apartment were researched by computer simulation. The parametric study of different hot water supply flow rates was done with regard to energy performance and control characteristics, respectively. Also the effect of different hot water supply flow rates on the hot water supply temperatures is studied. As a result, energy consumption were reduced but the response time is increased by reducing the supply flow rate. And energy consumption can be saved by adjusting the hot water supply temperatures with different supply flow rates.