• Title/Summary/Keyword: Electronic Heating

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The Electric Properties And Fabrication of High Temperature Heating Elements of $MoSi_2$ (이규화몰리브덴 고온발열체의 전기적 특성 및 제조에 관한 연구)

  • 이후인;심건주;한상옥
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.07a
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    • pp.605-608
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    • 2001
  • Molybdenum disilicide is widely used for manufacturing high-temperature heating elements owing to its low electrical resistivity, good thermal conductivity, and ability to withstand oxidation at high temperatures. MoSi$_2$heating elements with 4-5wt% of montmorillonite type bentonite as plasticzer and a small amount of Si$_3$N$_4$, ThO$_2$, and B as additives was manufactured. Extruded rods of 3.7mmø and 6.7mmø diameter and 400mm long were fabricated using a vacuum extruder, which were then sinrered for 4-5 hrs. at the max. temperrature of 140$0^{\circ}C$. After 10 minute's oxidation treatment, the diameter of the rod is reduced. The heating elements thus prepared was stable at 1$700^{\circ}C$ and the physical properties such as specific electrical resistivity, hardness, apparent densisty, thermal expansion coefficient, and bending strength were almost identical with thoes of commercial heating elements. In this study we have tried to gain the practical knowledge of manufacturing MoSi$_2$heating elements so that it may be utilized later in a research of pilot scale and eventually be transferred to industry.

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A Study on Thermo-Bed Design Development of HPT System (HPT 방식의 온열침대 디자인 개발에 관한 연구)

  • Lee, Bong-Kyu
    • Journal of the Korea Furniture Society
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    • v.22 no.1
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    • pp.72-81
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    • 2011
  • These days, beds have been developed not as furniture to sleep in but Healthcare Furniture. The function of heating, non-electronic-waves and far-infrared rays have been added. Also, eco-friendly materials such as stone, mud, rubber and wood are combined to them together with the radiation-heating method using heat conduction through electronic coil and hot water circulation. Modern people suffer from stress and fatigue. The hot issue is "health." Focused on the health, the development of design for beds considering the influence electronic waves, anions, deep sleep and the density of toxic materials have on human bodies has become urgent. In this study, the trend, specification and efficiency of the functional health-related electronic coil technology are analyzed. Through the analysis, the environmental standards are set. According to them, technology, eco-friendly materials and additional functions for the development of the design are considered. Also, the government is promoting the IEC international standardization for the Korean traditional floor heating style beds. In preparation for that, we adopted new HPT method technology. It enables non-electronic-waves, low electricity and stable temperature maintenance control for the warm top and the cool bottom. Also, the head boards and the frames of the beds can be separated. Through this separation, the beds can be easily moved or installed. Eco-friendly materials such as Hinoki cypress wood and red clay and the existing tables function are combined to the head boards so they can be used as drawers and display shelves. If they are used as separate items, they can be used as covers. This is how we suggest the design for the heating beds.

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New Solid-phase Crystallization of Amorphous Silicon by Selective Area Heating

  • Kim, Do-Kyung;Jeong, Woong-Hee;Bae, Jung-Hyeon;Kim, Hyun-Jae
    • Journal of Information Display
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    • v.10 no.3
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    • pp.117-120
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    • 2009
  • A new crystallization method for amorphous silicon, called selective area heating (SAH), was proposed. The purpose of SAH is to improve the reliability of amorphous silicon films with extremely low thermal budgets to the glass substrate. The crystallization time shortened from that of the conventional solid-phase crystallization method. An isolated thin heater for SAH was fabricated on a quartz substrate with a Pt layer. To investigate the crystalline properties, Raman scattering spectra were used. The crystalline transverse optic phonon peak was at about 519 $cm^{-1}$, which shows that the films were crystallized. The effect of the crystallization time on the varying thickness of the $SiO_2$ films was investigated. The crystallization area in the 400nm-thick $SiO_2$ film was larger than those of the $SiO_2$ films with other thicknesses after SAH at 16 W for 2 min. The results show that a $SiO_2$ capping layer acts as storage layer for thermal energy. SAH is thus suggested as a new crystallization method for large-area electronic device applications.

Control of Connectivity of Ni Electrode with Heating Rates During Sintering and Electrical Properties in BaTiO3 Based Multilayer Ceramic Capacitors

  • Yoon, J.R.;Shin, D.S.;Jeong, D.Y.;Lee, H.Y.
    • Transactions on Electrical and Electronic Materials
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    • v.13 no.4
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    • pp.181-184
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    • 2012
  • $BaTiO_3$ based multilayer ceramic capacitors with Ni electrodes can be explained as 2-2 composites with different thermal expansion coefficient and sintering behaviors. To achieve the high capacitance and reliability of MLCCs, a homogenous Ni electrode configuration with high connectivity is required. We controlled the heating rates during sintering to achieve densification by suppressing grain growth. Experimental results revealed that a large heating rate gave high connectivity of Ni electrode, high capacitance, small dissipation factor, high breakdown voltage, and high reliability of MLCC chips.

A study on the efficiency of sloped type Double-skin System for the Curtailment of Heating/Cooling Load (냉난방부하 절감을 위한 경사형 이중외피시스템의 성능연구)

  • An, Hyung-Jun;Kim, Young-Tag;Choi, Chang-Ho;Lee, Hyn-Woo
    • Journal of the Korean Solar Energy Society
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    • v.24 no.4
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    • pp.77-87
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    • 2004
  • BIPV or double skin applied to the surface of the building, power and thermal load cannot both be increased. In the case of BIPV, because it is applied to the facade, incident solar energy decreases and efficiency drops off. The system in this paper complements these disadvantages and aims to decrease the heating & cooling load by transforming solar energy to electronic and thermal energy. The research in this paper is about the applicability of the clear PV attached double-skin system. And the PV electronic generation and the factors that affect the heating & cooling load such as the daily radiation, sun shading ratio, heating & cooling load, daylight luminance and glare distributions in the building are simulated.

Electrostatic Discharge Analysis of n-MOSFET (n-MOSFET 정전기 방전 분석)

  • 차영호;권태하;최혁환
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.11 no.8
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    • pp.587-595
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    • 1998
  • Transient thermal analysis simulations are carried out using a modeling program to understand the human body model HBM ESD. The devices were simulated a one-dimensional device subjected to ESD stress by solving Poison's equation, the continuity equation, and heat flow equation. A ramp rise with peak ESD voltage during rise time is applied to the device under test and then discharged exponentially through the device. LDD and NMOS structures were studied to evaluate ESD performance, snap back voltages, device heating. Junction heating results in the necessity for increased electron concentration in the space charge region to carry the current by the ESD HBM circuit. The doping profile adihacent to junction determines the amount of charge density and magnitude of the electric field, potential drop, and device heating. Shallow slopes of LDD tend to collect the negative charge and higher potential drops and device heating.

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Effects of sintering conditions of (Cd+Te) films on the properties of sintered CdS/CdTe solar cells ((Cd+Te)막의 소결조건이 CdS/CdTe 태양전지의 특성에 미치는 영향)

  • 노재성;임호빈
    • 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.

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Dielectric and Piezoelectric Characteristic of Low Temperature Sintering PMN-PNN-PZT Ceramics according to the Heating Rate (승온속도에 따른 저온소결 PMN-PNN-PZT 세라믹스의 유전 및 압전특성)

  • Kim, Kook-Jin;Yoo, Ju-Hyun;Hong, Jae-Il
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.11a
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    • pp.253-254
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    • 2007
  • In this study, in order to develop low temperature sintering multilayer piezoelectric actuator, PMN-PNN-PZT system ceramics were fabricated using $Li_2CO_3-Bi_2O_3$-CuO as sintering aids and their piezoelectric and dielectric characteristics were investigated as a function of heating rate. At sintering temperature of $900^{\circ}C$, with increasing heating rate, electromechanical coupling factor(kp), mechanical quality factor(Qm) and dielectric constant $({\varepsilon}_r)$ were increased.

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Optimization for Friction Welding of AZ31 Mg Alloy by Design of Experiments (실험계획법에 의한 AZ31마그네슘합금의 마찰접합시 최적공정설계)

  • Kang, Dae-Min;Kwak, Jae-Seob;Choi, Jong-Whan;Park, Kyeong-Do
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.10 no.4
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    • pp.64-69
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    • 2011
  • Magnesium alloy has been known as lightweight material in automobile and electronic industry with aluminum alloy, titanium alloy and plastic material. Friction welding is useful to join different kinds of metals and nonferrous metals they are difficult to be joined by such as gas welding, resistance welding and electronic beam welding. In this study, friction welding was performed to investigate optimization process of Mg alloy with a 20mm diameter solid bar. For that, the orthogonal array $(L_{9}(3^{4}))$ was used that contained four factors and each factor had three levels. Control factors were heating pressure, heating time, upsetting pressure and upsetting time. Also tensile tests were carried out to measure mechanical properties for welded conditions. The levels of heating pressure and upsetting pressure used were 15, 25, 35MPa, and 30, 50, 70MPa, respectively. In addition those of heating time and upsetting time were 0.5, 1, 1.5 sec and 3, 4, 5 sec., respectively, rotating speed of 2000rpm. From the experimental results, optimization condition was estimated as follows; heating pressure=35MPa, upsetting pressure=70MPa, heating time=1.5sec, upsetting time=3sec.

Development of Heating Roller Monitoring System for Lamination (라미네이션을 위한 히팅롤러 모니터링 시스템 개발)

  • Oh, Jae-Jun;Choi, Woon-Shik;Choi, Seong-Ju
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.30 no.10
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    • pp.677-682
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    • 2017
  • Lamination is used extensively in various industries. The type of lamination applied to the material depends on the precision level required, which varies for materials needed for everyday use, materials used in high-tech industries, and processes employed to fabricate finished products. Especially in hot lamination, the distribution of the surface temperature of the heating roller is very important to avoid the generation of internal bubbles and ensure flatness of the attached materials, and thus maintain a good standard of quality and productivity. In this study, we have developed a system to monitor the surface temperature of the heating rollerby applying a heterogeneous controller and a non - contact temperature sensor. This monitoring system accurately measures the surface temperature of the heating roller and applies the RS485 MODBUS communication method for easy expansion. Using this system, a laminated prototype was fabricated, and its efficacy for non-contact temperature sensor calibration, Ethernet IP communication, stoppage of the heating roller, and determination of temperature distribution with rotation was examined for its potential usage in industries.