• Applied Microscopy
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• v.31 no.4
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• pp.315-323
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• 2001

In situ TEM heating experiments utilizing kaolinite powder samples result in the following facts. (1) The water recirculation system adopted in the Gatan's heating holder is required to prevent specimen drift above $500^{\circ}C$. (2) Since the degree of phase changes depends on the thickness of powders below $600^{\circ}C$, examinations of both thin and thick specimens are required. (3) Sample preparation using Mo-grids is required for TEM heating experiments above $900^{\circ}C$. At these temperature ranges the effect of heating rate and holding time on the phase transition process increases drastically, so that a programmed temperature control is required. (4) TEM heating experiments of the embedded powders by epoxy for the cross-sectional view was limited due to the severe epoxy movement during heating above $300^{\circ}C$. Better methods of sample preparation are required to overcome this problem.

• Journal of the Society of Naval Architects of Korea
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• v.39 no.2
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• pp.34-44
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• 2002

Approximately 70 percent of shop's hull plate consists of three-dimensional curved shell. Concerning with the research on the automation of plate forming many studies have been carried out for the last decade. The purpose of this study is to develop the simulator of heating on the basis of the reasonable mechanical model representing a heating phenomenon. The beating experiment has been carried out with varying parameters influencing on the results of heating information at the kinematics analysis, simulatorestimate the shape of deformed plate that process along the processing information. When we get the initial shape and the object shape, we calculate the processing information first, using kinematics analysis. In a simulator we estimate deformed shape from the processing information. After this we compare deformed shape and object shape. If the error of deformed shape and object shape is in the proper limits, that information is determined the final processing information. Else we repeat the process changing variable.

• Proceedings of the KAIS Fall Conference
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• 2000.10a
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• pp.223-225
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• 2000

일반적으로 많이 사용되는 고강도 스티로폼은 원료모분을 스팀발포기를 사용하여 수십배로 일차 발포한 후 금형에 넣어 스팀으로 성형한다. 이러한 스티로폼은 단열성이 뛰어난 장점이 있지만 강도가 약하여 내구성이 요구되는 재료로는 부적당하였다. 한편 자동생산공정에 사용되는 로봇 트레이는 고강도 정전기 방지 기능이 필요하게 되었고, 5배 정도의 저발포 스티로폼을 이용한 로봇 트레이가 일부 생산되고 있다. 스팀을 이용한 성형 가공의 경우 모분이 표면에서 발포 융착된 후 내부로 열이 잘 전달되지 못하여 내부 융착이 잘되지 않는 단점을 가지고 있다. 이 단점을 보완하기 위하여 물의 높은 유전율을 이용한 유전가열을 사용하여 내부 융착을 용이하게 시킬 수 있다. 본 연구는 원료모분을 3배이하로 일차 발포한 폴리스틸렌 원료를 이용하여, 스팀에 의한 성형이 아닌 고주파 유전가열을 이용한 성형 방법에 의하여 만들어진 성형물의 비젼과 문제점을 제시하였다. 본 연구에 사용한 고주파는 나무 집성가공에 많이 사용되는 13.6MHz를 사용하였고, 금형은 두랄루민 금형과 목형을 사용하여 시험하였으며, 이의 장단점 및 문제점을 비교하였다. 스팀성형가공에 비하여 내부융착이 훨씬 뛰어났으며, 일부 문제점을 보완하면 진보된 생산공정이 될 것으로 기대된다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.1237-1238
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• 2010

• Vending industry
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• v.5 no.1 s.13
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• pp.43-45
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• 2005

먹기 편한 레토로트 즉석죽을 발열체가 내장된 파우치에 포장해 자동판매기를 통해 판매하는 사업이 선보였다. 지엘텍은 신개념의 죽자판기 사업을 선보이고 식품자판기 분야의 새로운 사업 유형을 제시하고 있다. 기존 즉석죽 시장의 성장과 함께 무인 유통사업으로의 큰 성장을 노리는 웰빙 죽자동판매기의 흥미진진한사업 행보를 따라가 봤다.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.12
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• pp.828-836
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• 2010

The drying is a process that involves coupled and simultaneous heat and mass transfer. When a wet solid is subjected to thermal drying, two processes occur simultaneously. Drying is classified according to heat transfer characteristics in terms of conduction, convection and radiation. In thermal drying, radiation is easier to control than conduction and convection drying and involves a relatively simple structure. In this study, we measured energy consumption, surface hardness of paint and surface gloss with variation of surface temperature of drying materials and drying time. Drying characteristics and energy consumption between heating panels and hot air heating have been presented. The present study shows that a dryer using heating panels is more effective than a hot air dryer from the viewpoint of energy conservation. The hot air dryer, however, was not optimized and more studies on various parameters related to drying will need to be investigated for definite comparison of drying characteristics of the dryers. The result, even if limited, would present the effective availability of paint drying.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.352-358
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• 2011

This paper describes on the study of mitigation technique in which a pyrosensor is automatically sensing the rate of risk of fire or explosion of solid rocket motor exposed to an unexpected fire and makes the rocket motor burn itself safely. SCO test was carried out with a rocket motor loaded with HTPB propellant, in which a thermal pyrosensor igniter was installed. The rocket motor in SCO test was located in an oven at $50^{\circ}C$ for 7 hours. The temperature was regulated to be elevated at the rate of $3.3^{\circ}C$ per hour. Results showed Type V(Burning) reaction in this SCO test.

• Journal of the Korean Society of Propulsion Engineers
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• v.16 no.6
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• pp.85-91
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• 2012

This paper describes the results of study on reaction of insensitive igniter in which a pyrosensor is automatically sensing the rate of risk of fire or explosion of solid rocket motor exposed to an unexpected fire and makes the rocket motor burn itself safely. The Slow Cook Off(SCO) test following the regulation of MIL-STD-2105D was carried out with a rocket motor loaded with HTPB propellant, in which a thermal pyrosensor igniter was installed. The auto-ignition temperature measured was approximately $140^{\circ}C$ and it corresponded to Type V(Burning) reaction in SCO test, while the temperature by Kissinger equation was calculated to be $165.5^{\circ}C$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.1
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• pp.93-98
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• 2005

Total tocopherol and phenol contents were determined for virgin and pure oilve oil, and their autoxidation and thermal oxidation were compared with those of commercial soybean oil, in the presence or absence of fluorescent light. The total tocopherol contents of virgin, pure olive oil, and soybean oil were 15.7, 11.2, and 80.7 mg/100 g, respectively. Their total phenol contents were 10.4, 1.6 and 0.5 mg/l00 g, respectively. In autoxidation under dark place at 45$^{\circ}C$, the oxidative stability of the substrate oils decreased in order of virgin oilve oil, pure olive oil, and soybean oil. The average temperature coefficients of the virgin, pure olive oil and soybean oil in the range of 45∼$65^{\circ}C$ were 1.73, 1.83 and 1.64, and the activation energies were 26.86, 29.49, and 24.07 KJ/mol, respectively. In temperature range of 45∼$65^{\circ}C$, pure olive oil was the most susceptible to temperature change, whereas soybean oil the least. In autoxidation under fluorescent light at 45$^{\circ}C$, the oxidative stability of substrate oils decreased in the order of soybean oil, pure olive oil, and virgin olive oil. In thermal oxidation at 18$0^{\circ}C$, the oxidative stability of substrate oils decreased in order of pure olive oil, virgin olive oil, and soybean oil.

• Proceedings of the KAIS Fall Conference
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• 2001.05a
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• pp.224-228
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• 2001

자동차용 Al Wheel의 반복 금형 주조 공정에 있어서의 적정 냉각조건 확립 및 수축공 등의 주조결함을 제어하기 위하여 3차원 응고, 유동, 응력 해석 프로그램 연동 기술과 자동 금형온도 조절장치를 실제 현장에 적용하여 생산되는 Al Wheel 제품의 최적 주조조건 및 냉각조건을 확립하였다. 주조과정 중의 금형의 온도 변화 및 주물의 응고, 유동 거동은 수치해석 결과와 잘 일치하는 경향을 나타내었다. 또한 금형온도 자동 조절 장치를 사용함으로서 금형 작업온도의 가열 및 유지가 정량적으로 제어 가능하며, 제품 품질의 유지 및 Cycle Time 최적화를 이룰 수 있으며 궁극적으로는 금형 수명 연장 및 생산성 향상 등을 이룰 수 있었다.