• Mass Spectrometry Letters
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• v.6 no.3
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• pp.71-74
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• 2015

Low temperature plasma (LTP) ionization mass spectrometry (MS) is one of the widely used ambient analysis methods which allows soft-ionization and rapid analysis of samples in ambient condition with minimal or no sample preparation. One of the major advantages of LTP MS is selective analysis of low-molecular weight, volatile and low- to medium-polarity analytes in a sample. On the contrary, the selectivity for particular class of compound also implies its limitation in general analysis. One of the critical factors limiting LTP ionization efficiency is poor desorption of analytes with low volatility. In this study, a home-built LTP ionization source with Peltier heating sample stage was constructed to enhance desorption and ionization efficiencies of analytes in a sample and its performance was evaluated using standard mixture containing fatty acid ethyl esters (FAEEs). It was also used to reproduce the previous bacterial identification experiment using pattern-recognition for FAEEs. Our result indicates, however, that the bacterial differentiation from FAEE pattern recognition using LTP ionization MS still has many limitations.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1400-1404
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• 2005

This paper presents the temperature control of aluminum plate by using Peltier element. Peltier effect is heat pumping phenomena by electric energy as one of the thermoelectric effect. So if current is charged to Peltier element, it absorbs heat from low temperature side and emits heat to high temperature side. In this experiment, Peltier element is used to control the temperature of small aluminum plate with current control and operating cooling fan only while cooling duration. Operating cooling fan only while cooling duration is proper to get more rapid heating and cooling duration. As a result of experiment, it takes about 100sec period to repeating temperature between $35^{\circ}C$ and $70^{\circ}C$ and about 80sec from $40^{\circ}C$ to $70^{\circ}C$ in ambient air temperature $25^{\circ}C$ and while operating cooling fan only in cooling duration. Future aim is to apply this temperature control method in actuating SMHA(special metal hydride actuator) which is applicable in Siver project acting in low frequency range by using Peltier element for heating and cooling.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.665-667
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• 2005

VIATRON TECHNOLOGIES has developed FE-RTP system that enables LTPS LCD and AMOLED manufacturers to produce poly-Si films at low cost, high throughput, and high yield. The system employs sequential heat treatment methods using temperature control and rapid thermal processor modules. The temperature control modules provide exceptionally uniform heating and cooling of the glass substrates to within ${\pm}2^a\;C$. The rapid thermal process that combines heating with field induction accelerates the treatment rates. The new FE-RTP system can process $730{\times}920mm$ glass substrates as thin as 0.4 mm. The uniform nature of poly-Si films produced by FE-RTP resulted in AMOLED panels with no laser-Muras. Furthermore, FE-RTP system also showed superior performances in other heat treatment processes involved in poly-Si TFT fabrications, such as dopant activation, gate oxide densification, hydrogenation, and pre-compaction.

• Journal of the Korean Society for Heat Treatment
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• v.18 no.3
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• pp.172-176
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• 2005

Modern automobiles are built with a steadily increasing variety of materials and semifinished products. The traditional composition of steel sheet and cast iron is being replaced with other materials such as aluminum and magnesium. But low formability of these materials has prevented the application of the automotive components. The formability can be enhanced by conducting the warm hydroforming using induction heating device which can raise the temperature of the specimen very quickly. The specimen applied to the test is A6061, A7075 extruded tubes which belong to the age-hardenable aluminum alloys. But in the case of A6061 age hardening occurs at room temperature or at elevated temperatures before and after the forming process. In this study the effects of the heating condition such as heating time, preset temperature, holding time during die closing and forming time on the hydroformability are analyzed to evaluate the phenomena such as dynamic strain hardening and ageing hardening at high temperatures after the hydroforming process.

• Journal of Ginseng Research
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• v.22 no.3
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• pp.193-199
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• 1998

The purpose of this study was to Investigate characteristics of the water soluble browning reaction products (WS-BRPs) from Korean red ginseng by heat treatment. Absorbance of WS- BRPs was increased with increases of heating temperature and time, but pH value were decreased In Muter color value L and b value were decreased, while a value was increased. and absorbance at 280 nm in spectrum of the WS-BRPs was increased according to the increase of heating temperature. When the WS-BRPs were applied on Bio-Gel P-30 column after heating and pH treatment, two majors browning products increased according to the progress on time. And pH 3.0 increased in quantity of high molecular fractions and pH 8.0 increased in quantity of low molecular fractions.

• Journal of Sensor Science and Technology
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• v.29 no.4
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• pp.220-226
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• 2020

Graphene has been widely considered a promising candidate for high-quality chemical sensors, owing to its outstanding characteristics, such as sensitive gas adsorption at room temperature, high conductivity, high flexibility, and high transparency. However, the main drawback of a graphene-based gas sensor is the necessity for external heaters due to its slow response, incomplete recovery, and low selectivity at room temperature. Conventional heating devices have limitations such as large volume, thermal safety issues, and high power consumption. Moreover, metal-based heating systems cannot be applied to transparent and flexible devices. Thus, to solve this problem, a method of supplying the thermal energy necessary for gas sensing via the self-heating of graphene by utilizing its high carrier mobility has been studied. Herein, we provide a brief review of recent studies on self-activated graphene-based gas sensors. This review also describes various strategies for the self-activation of graphene sensors and the enhancement of their sensing properties.

• Journal of The Korean Society of Agricultural Engineers
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• v.50 no.4
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• pp.59-66
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• 2008

Anaerobic digestion system is getting more attractive in that it produces biogas in the process of organic waste stabilization. Net energy production is important when biogas production is concerned. In this study, net energy production was evaluated with respect to biogas production and heat losses in a hypothetical digester. Under the condition of digester operation with slurry inflow of 5% of TS, additional fuel is required to maintain digester temperature during the winder season. Substrate therefore, needs to have higher VS contents through co-digestion of silage or food waste that has greater values of methane production rate. Heating input slurry is important in cold season, which covers over 80% of heating requirement. Heat recovery from digestate is valuable to reduce the use of biogas for heating. It seems desirable to minimize slurry inflow when temperature is very low. Psychrophilic digestion may be a feasible option for reducing heating requirement.

• Electrical & Electronic Materials
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• v.1 no.1
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• pp.26-34
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• 1988

Sintered CdS/CdTe solar cells have been farbricated by coating a (Cd+Te) slurry on sintered CdS films followed by the sintering at 625.deg.C for one hour with various heating rates. When cadmium and tellurinm powders are used instead of CdTe powder to form CdS/CdTe junction, CdTe is formed in the temperature range of 290.deg.C-400.deg.C. The microstructure of the CdTe films depends strongly on the heating rate of the sintering due to the low melting temperature and the high vapor pressure of the elemental Cd and Te. An optimum heating rate obtain CdTe films with uniform and dense microstructure which, in turn, improves the efficiency of the sintered CdS/CdTe solar cells. All-polycrystalline CdS/CdTe solar cells with an efficiency of 9.57% under 50mW/cm$^{2}$ tungsten light have been farbricated by using a heating rate of 14.deg.C/min.

• Journal of the Institute of Convergence Signal Processing
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• v.19 no.2
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• pp.61-67
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• 2018

Welding preheating means that the surface of the base material to which the metal is welded before the main welding is heated to a constant temperature. It prevents the cracks of the adjacent influences such as reduction of material hardening degree by controlling the cooling rate, suppression of segregation of impurities, prevention of thermal deformation, and moisture removal. For this reason, it is a necessary operation for high quality welding. Induction heating is an efficient heating method that converts electric energy into heat energy by applying electromagnetic induction phenomenon. Compared with combustion heat generated by gas and liquid, it is clean, stable, and economical as well as rapid heating. It can be heated regardless of the shape, depth and material of the heating body by modifying the shape of the frequency and the coil with a simple structure. In this paper, we implemented a low frequency welding preheating system using induction heating technique and observed the temperature changes of coil resistance, inductance and automotive transmission parts according to the height of each transmission in winding coil for three kinds of automotive transmission parts. We confirmed that the change of current is a very important factor in the low frequency heating.

• Proceedings of the KAIS Fall Conference
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• 2001.05a
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• pp.281-283
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• 2001

The low foamed high strengthen styrofoam samples made by dielectric heating are discussed. We used the oscillator which have the frequency of 13.6MHz and the Power of 7kW. 3 times expanded beads by steaming method were used in our foam-molding test. Internal fusion properties and density of internal structure were improved by dielectric foaming process. At the temperature of 105-110$^{\circ}C$, the internal fusion property was maximally improved.