• Nuclear Engineering and Technology
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• 제35권4호
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• pp.309-317
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• 2003

The mass balance of the unit processes of the Advanced spent fuel Conditioning Process was calculated to obtain basic information. Based on this mass balance, the changes in decay heat and radioactivity of the spent fuel due to the metallization in the high temperature molten salt system were estimated. The decay heat and the radioactivity were calculated by using the ORIGEN2 computer code, and the result showed that the decay heat and the radioactivity of the metallized spent fuel ingot were $24.27\%\;and\;24.24\%$, respectively, compared to those of oxide spent fuel.

• Journal of applied mathematics & informatics
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• 제9권2호
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• pp.731-744
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• 2002

The temperature distribution in human skin and subdermal tissue layer is presented using bioheat transfer equation. The body temperature is determined by the balance between heat produced and heat lost by our body. The time-dependent solutions have been found to be affected by the metabolic heat generation rate, blood mass flow, the rate of evaporation of perspiration and also by the atmospheric temperature. The analytic solutions for different layers have been calculated numerically and are also shown graphically.

• 터널과지하공간
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• 제21권4호
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• pp.297-306
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• 2011

본 연구에서는 지하 압축공기에너지 저장공동 주변 지하수 및 압축공기의 유체유동과 열전달 거동 해석을 위한 다상다성분 열유동 해석 결과를 이용하여 지하 저장공동의 열역학적 에너지수지 분석을 통한 에너지 효율평가를 실시하였다. 복공재인 콘크리트 라이닝이 충분한 기밀성능을 발휘할 경우, 주입 압축과정에서 저장공동으로부터 손실되는 에너지의 대부분은 콘크리트 라이닝 및 주변 암반에의 열전도를 통해 발생함을 확인하였다. 지하 압축공기에너지 저장공동의 에너지 효율은 압축공기 주입온도에 민감한 결과를 보였으며, 주입온도가 주변 암반의 온도에 근사할 경우, 손실된 에너지의 대부분이 토출 팽창과정에서 저장공동으로 유입 회수되는 결과를 보였다. 한편, 콘크리트 라이닝의 열전도특성이 저장공동의 에너지효율에 미치는 영향은 크지 않았다.

• 한국연소학회지
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• 제21권1호
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• pp.18-30
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• 2016

Pyro-process of solids is the way to heat solid materials under high temperature. In this processing, energy efficient use is one of the main concerns due to its high energy consumption of bulk materials. To calculate the energy use of processes, heat & mass balance in simplified 0-dimensional model was performed. Energy calculation by this simplified model can lead to confusion due to simplification. Thus, it is necessary to understand considerations of energy analysis. In this study, cement manufacturing as a very common example of pyro-processing of solids, was introduced for explaining considerations of energy analysis for energy efficient use.

• 운동영양학회지
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• 제13권1호
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• pp.75-81
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• 2009

This study aims to find out the effect of ingestion of 3 mg·kg^-1 caffeine on fluid-electrolyte balance and Tty change during exercise under heat environment of 30~32℃ (40-50% humidity). Five trained males who routinely trained for approximately 60 min·d^-1, 3-6 d·wk^-1 (age; 28.20±3.56yrs, height; 174.56±5.46 cm, body mass; 76.13±9.02 kg, body fat(%); 14.24±3.99, VO₂max; 54.00±4.30 mL·kg^-1·min^-1, exercise career; 4.20±1.95yrs) performed 40min of treadmill running in heat chamber. The study was a double-blind, randomized, crossover design. Body mass change following exercise was higher for the PLAC (Placebo) and CAFF (Caffeine) in comparison to the CON (Control), there was no significant difference between the CAFF, PLAC, CON (p= .997). The U_sg not significant differences (p= .731) and Osm_urine not significant differences between the CAFF, PLAC, CON (p= .901). There also were not significant between the CAFF, PLAC, CON for [Na⁺]_urine and [K⁺]_urine (p= .928, p= .469). In the case of Tty, although the increase rate of Tty was the highest for the CAFF on exercise early, exercise the second half in comparison to the CON and PLAC, there was not significant interaction effect between the CAFF, PLAC, and CON of Tty (p= .067), In conclusion, it was confirmed that the 3 mg·kg^-1 caffeine ingestion prior to exercising in heat environment does not impart negative effect on body fluid, electrolyte balance and changes in Tty.

• KEPCO Journal on Electric Power and Energy
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• 제6권4호
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• pp.427-432
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• 2020

본 연구에서는 화력 발전소 보일러에 대한 연소 및 열전달 해석을 위하여 화로 내부를 다중영역으로 나누고 각 영역에서 energy와 mass balance는 1차원으로 계산하고, 복사열전달은 3차원으로 계산하는 다중영역분할 화로해석 기법을 활용하였다. 그리고 적용 기법에 대한 신뢰성 검증을 위하여 국내 500 MW 급 석탄화력 보일러 화로에 대한 계산 값과 보일러 제작사의 설계 데이터를 비교하여 양호함을 확인하였고, 동일한 설비에 대한 CFD 해석과 비교한 결과 유사한 경향을 얻었다. 본 계산 기법은 CFD 화로해석 보다는 덜 상세하지만, 빠른 시간에 연료반응성, 화로형상 및 운전변수에 따른 특성을 계산할 수 있는 장점이 있으므로 발전소 현장에서의 설비감시진단 및 일일 연료/운전 계획 수립 등 활용성 측면에서 유용할 것으로 예상된다.

• 대한금속재료학회지
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• 제47권5호
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• pp.304-310
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• 2009

Recently, manganese nodule has been focused on alternative resources because of its high grade of noble metallic elements such as Co, Ni, and Cu etc. From the viewpoint of an optimization the operating variables for energy efficiency of smelting reduction process, thermodynamic model for smelting reduction process of Manganese nodule was developed by using energy and material balance concept. This model provided that specific consumption of pure oxygen and coke was strongly depended on post combustion ratio (PCR) and heat transfer efficiency (HTE). The dressing and dehydrating process of low grade manganese can be proposed an essential process to minimize the specific energy consumption with decreasing slag volume. The effect of electricity coal base smelting reduction process was also discussed from the energy optimizing point of view.

• 대한한의학회지
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• 제42권4호
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• pp.185-196
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• 2021

Objectives: Many symptoms of cold and heat patterns are related to the thermoregulation of the body. Thus, we aimed to study the association of cold and heat patterns with anthropometry/body composition. Methods: The cold and heat patterns of 2000 individuals aged 30-55 years were evaluated using a self-administered questionnaire. Results: Among the anthropometric and body composition variables, body mass index (-0.37, 0.39) and fat mass index (-0.35, 0.38) had the highest correlation coefficients with the cold and heat pattern scores after adjustment for age and sex in the cold-heat group, while the correlation coefficients were relatively lower in the non-cold-heat group. In the cold-heat group, the most parsimonious model for the cold pattern with the variables selected by the best subset method and Lasso included sex, body mass index, waist-hip ratio, and extracellular water/total body water (adjusted R² = 0.324), and the model for heat pattern additionally included age (adjusted R² = 0.292). Conclusions: The variables related to obesity and water balance were the most useful for predicting cold and heat patterns. Further studies are required to improve the performance of prediction models.

• 한국농공학회지
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• 제32권E호
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• pp.88-94
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• 1990

Several models physically based to predict the evolution of the snowpack have been proposed. Validity of these models for hourly estimation is, however, questionable, since they have been tested only on a daily basis. A computational model to predict the amount of snowpack on an hourly basis in terms of snowload from a set of meterological measurements was developed and investigated the rapid snowmelt conditions during Fohn events in the Takada plain.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집B
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• pp.104-107
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• 2000

Evaporative heat transfer characteristics of carbon dioxide has been investigated. Experiment has been carried out for seamless stainless steel tube with outer diameter of 9.55 mm and inner diameter of 7.75 mm. Direct heating method is used for supplying heat to the refrigerant was uniformly heated by electric current which was applied to the tube wall. The saturation temperature of refrigerant is calculated from the measured saturation pressure by using an equation of state. Inner wall temperature was calculated from measured outer wall temperature, accounting for heat generation in the tube and heat conduction through the tube wall. Mass Quality of refrigerant was calculated by considering energy balance in the preheater and the test section. Heat fluxes were set at 12, 16, 20, 23, and $27kW/m^2$, mass fluxes were controlled at 212, 318, 424, and $530 kg/m^2s$, and saturation temperature of refrigerant were adjusted at 0, 3.4, 6.7 and $10.5^{\circ}C$. From this study, heat transfer coefficients of carbon dioxide have been provided with respect to quality for several mass fluxes, heat fluxes. Finally, the experimental results in this study are compared with the correaltion by Gungor and Winterton(1987).