• Nuclear Engineering and Technology
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• v.23 no.1
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• pp.66-80
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• 1991

The LOFT intermediate break experiment L5-1, which simulates 12 inch diameter ECC line break in a typical PWR, has been analyzed using the reactor thermal/hydraulic analysis code RELAP5/MOD2, Cycle 36.04. The base calculation, which modeled the core with single flow channel and two heat structures without using the options of reflood and gap conductance model, has been successfully completed and compared with experimental data. Sensitivity studies were carried out to investigate the effects of nodalization at reactor vessel and core modeling on major thermal hydraulic parameters, especially on peak cladding temperature(PCT). These sensitivity items are : single flow channel and single heat structure (Case A), two flow channel and two heat structures (Case B), reflood option added (Case C) and both reflood and gap conductance options added (Case D). The code, RELAP5/MOD2 Cycle 36.04 with the base modeling, predicted the key parameters of LOFT IBLOCA Test L5-1 better than Cases A,B,C and D. Thus, it is concluded that the single flow channel modeling for core is better than the two flow channel modeling and two heat structure is also better than single heat structure modeling to predict PCT at the central fuel rods. It is, therefore, recommended to use the reflood option and not to use gap conductance option for this L5-1 type IBLOCA.

• Journal of the Korean Society of Food Culture
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• v.22 no.5
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• pp.603-608
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• 2007

Optimal winterizing condition of com oil was cooling temperature of bleached oil from $105^{\circ}C$ to $40^{\circ}C$. Then, filtering it after keeping $1{\sim}2^{\circ}C$ by lowering the temperature gradually with treating perlite of 0.3%(w/w) amount about bleached oil and stirring. We could measure that triglyceride(TG) that extracted from lipid components from spent perlite(SP) obtained through filtration after winterizing by SACC method is major causing materials of clouding in com oil. The result of separating TG fraction by agentation TLC was that it classified into 4 kinds -U3, SU2, S2U, S3 type and the most were U3 type. From this, it's easy to identify cause of clouding in com oil is TG fraction and most of them form wax materials that can observed. The results were they kept clear appearance at $0^{\circ}C$ generally during 39.6 to 96.5 hours, especially the result of A sample that had the lowest temperature condition while they have some difference by condition of treating temperature.

• Food Science and Preservation
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• v.11 no.4
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• pp.485-490
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• 2004

Crude corn oil (CCO) was obtained through the expression-extraction process from corn germ. The CCOs of final process at $90^{\circ}C,\;70^{\circ}C\;and\;50^{\circ}C$ were stored in outdoor storage tanks. From the samples, refined CCO (RCCO) were prepared with $0\%,\;10\%\;and\;20\%$ excessive of phosphoric acid, caustic solution and acidic clay were used in degumming-alkali refining-bleaching process. RCCOs were stored at room temperature in dark places. The color change was not effected by the amount of phosphoric acid, caustic solution and acidic clay, but temperature of process affects the color change. Finally, the prevention for color reversion of RCCO could be obtained by lowering the temperature of final process and optimal temperature of RCCO in summer was found about less than $50^{\circ}C$.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.10
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• pp.1493-1498
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• 2010

This paper present the characteristics of micro- and meso-scale milling processes in which compressed cold air, minimum quantity lubrication (MQL) and $MoS_2$ nanofluid MQL are used. For process characterization, the microand meso-scale milling experiments are conducted using desktop meso-scale machine tool system and the surface roughness is measured. The experimental results show that the use of compressed chilly air and nanofluid MQL in the micro- and meso-scale milling processes is effective in improving the surface finish.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.12
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• pp.881-889
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• 2019

The pre-swirl system is the device that minimizes energy loss of turbine cooling airflow from the stationary parts into rotating parts. In this paper, an off-design analysis was conducted for the ambient air temperature and turbine load conditions. The discharge coefficient was constant for ambient air temperature and turbine load. However, adiabatic effectiveness was increased. This is due to the volume flow rate. The volume flow rate was increased at higher ambient temperature and higher turbine load. It means that the volume of cooling air was increased and the cooling performance of the air was improved. Consequently, adiabatic effectiveness increased by 30.46% at 100% turbine load compared to 20% turbine load. And increased by 18.42% at 55℃ ambient air temperature compared to -20℃ ambient air temperature.

• Journal of the Korean Society of Propulsion Engineers
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• v.26 no.2
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• pp.72-78
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• 2022

A vacuum brazed cooling passage for an aircraft engine controller was designed. In order to predict the total pressure loss, which is the main design factor of the cooling passage, theoretical and numerical methods for the major loss and the minor loss considering the overall shape of the cooling passage are presented. This design and evaluation method can predict the pressure loss of the complex cooling passage shape for various flow conditions at the initial design step.

• 월간낙농육우
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• v.35 no.10
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• pp.101-104
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• 2015

목장에서 겨울철 젖소에게 따뜻한 물을 공급하기도 하고, 착유장비(우유의 이송관 등)과 원유 냉각탱크를 세척하기 위해서도 사용하는 온수기는 깨끗하고 신선한 유질을 유지하기 위해 꼭 필요한 장비로 꼽힌다. 목장 경영의 필수품인 온수기를 수입해 농가에 공급하며 유질의 향상과 생산비 절감을 위해 노력하고 있는 (주)에버하트(서울시 성동구 성수동) 이길주 대표는 가격대비 최고의 제품을 목장에 공급하는 한편, 400여 곳 이상의 대리점을 확보해 목장에서 온수기 사용에 불편함이 없도록 전력을 기울이고 있다.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1990.10a
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• pp.53-56
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• 1990

When oil flows and rubs against various materials in transformer, electrostatic charges are separated at the interface of the oil and the solid material. Using simplified model transformer, authors investigated the basic characteristics of the streaming electrifica-tion which is caused by forced oil circulation. As the result of the study, it was concluded that the electrostatic charge distribution on test pipe of the transformer showed larger leakage current at the inlet and the outlet.

• Journal of the KSME
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• v.35 no.7
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• pp.638-646
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• 1995

직접접촉 얼교환 기술은 냉각탑, 접촉급수 가열기 및 공기분리기 등과 같은 장치에 예전부터 이용되어 왔는데, 그 주요한 적용이유는 가열유체와 수열유체의 사이에 일어나는 전열이 일반 열교환기와는 달리 고체벽(금속 열전달표면)을 통과하지 않고 열교환을 함으로써, 종래의 열교 환기에 비하여 상대적으로 설비의 간단화, 부식 및 스케일 부착문제가 경감됨에 따른 적은 유 지보수비 및 높은 열전달률을 얻을수 있는 이점이 있으며, 저 온도차에서의 효율적인 사용이 가능하기 때문이다. 이 글에서는 직접접촉응축 현상의 장점을 이용하는 직접접촉식 교환기의 구조와 형태, 그리고 그 응용분야에 대해서 알아보고자 한다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.04b
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• pp.215-219
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• 1995

요사이 공작기계는 고생산성을 위해 고속절삭과 강력 절삭이 가능하도록 설계되고, 고성능의 Controller를 부착하여 이송과 공구착탈에 필요한 비절삭 시간을 급격히 단축시켜 나가고 있다. 본 연구에서는 공작기계 주축 베어링의 비대칭 벌열의 원인과 발열형태를 이론적으로 예측하고, 실험에 의해 비대칭 발열과 냉각특성 을 운전조건 별로 확인하였다. 또한 비대칭 발열이 주축대의 열변형에 어떤 영향을 미치는지 알기 위해 유 한요소법에 의해 열변위 특성을 분석하였다.