• Title/Summary/Keyword: thermal activation

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Improvement of Carrier Mobility on Silicon-Germanium on Insulator MOSFET Devices with a Strained-Si Layer

  • Cho, Won-Ju;Koo, Hyun-Mo;Lee, Woo-Hyun;Koo, Sang-Mo;Chung, Hong-Bay
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.20 no.5
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    • pp.399-402
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    • 2007
  • The effects of heat treatment on the electrical properties of strained-Si/SiGe-on-insulator (SGOI) devices were examined. We proposed the optimized heat treatment processes for improving the back interfacial electrical properties in SGOI-MOSFET. By applying the additional pre-RTA (rapid thermal annealing) before gate oxidation step and the post-RTA after source/drain dopant activation step, the electrical properties of strained-Si channel on $Si_{1-x}Ge_x$ layer were greatly improved, which resulting the improvement of the driving current, transconductance, and leakage current of SGOI-MOSFET.

NO gas sensing properties of modified multi wall carbon nanotubes (MWCNTs) by thermal fluorination and activation (열처리로불소화 및 활성화된 탄소나노튜브의 NO 가스센서 특성)

  • Kim, Min Il;Park, Mi-Seon;Lee, Sei Hyun;Lee, Young-Seak
    • Proceedings of the KIEE Conference
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    • 2015.07a
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    • pp.1543-1543
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    • 2015
  • 반도체식 가스센서의 한계를 극복하기 위하여 열불소화 방법과 활성화 방법을 이용하여 NO 가스 감지용 가스센서를 제조하였으며, 각각의 특성을 평가하였다. 열불소화 처리된 탄소나노튜브는 열처리 온도에 따라 반도체적 성질이 p-type에서 n-type으로 변화한 후 다시 p-type으로 변화하였으며, 활성화 처리된 탄소나노튜브는 비표면적이 증가할수록 NO 감지에 따른 저항변화가 증가하였다. 저항변화율은 $200^{\circ}C$에서 불소화 처리된 탄소나노튜브가 가장 크게 나탔으나 응답시간을 고려할 경우 $600^{\circ}C$에서 불소화 및 6M의 KOH를 이용한 경우 가장 우수한 특성을 보였다.

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A Study on Spontaneous Ignition of Granulated Activated Carbon (입상활성탄의 자연발화에 관한 연구(I))

  • 목연수;최재욱;김상렬;최광재
    • Journal of the Korean Society of Safety
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    • v.6 no.4
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    • pp.66-72
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    • 1991
  • Spontaneous ignition characteristics were observed by performing experiments for granulated activated carbon at constant ambient temperature in an oven. As the results of the experiments, the critical spontaneous ignition temperature of sample for large, intermediate and small vessels was 158.5$^{\circ}C$ , 165.5$^{\circ}C$ and 174.5$^{\circ}C$, respectively. It was found that the critical spontaneous ignition temperature decreased and the ignition induction time increased as the sample vessel size increased. Apparent activation energy of the sample calculated from the Frank= kamenetskii's thermal ignition theory was 17.81*10$^3$J/mol.

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Development and Applications of Frame Retardant Nano and Microcapsule (난연기능 nano 및 microcapsule의 개발 및 응용(Ⅰ))

  • Kim, Hea-In;Hong, Yo-Han;Park, Soo-Min
    • Textile Coloration and Finishing
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    • v.20 no.4
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    • pp.31-42
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    • 2008
  • Tricrecyl phosphate(TCP)-containing polyurea microcapsules were prepared by interfacial polymerization using aromatic 2,4-toluene diisocyanate(TDI) and ethylenediamine(EDA) as wall forming materials. The effects of the protective colloids of polyvinylalcohol(PVA) and gelatin were investigated through experimentation. The mean size of prepared polyurea microcapsules was smaller and the surface morphology of the microcapsule prepared by the PVA as protective colloid was much smoother than the gelatin. As the concentration of protective colloid increased, the wall membrane of the polyurea microcapsules became more stable, the thermal stability of the wall membrane increased, the mean particle size became smaller, and the particle distribution was more uniform. PET containg microTCPs have a higher activation energy of decomposition, higher char content and lower heat of combustion.

A Fundamental Study for a Photocatalytic Reactor Design (광촉매 반응치 설계를 위한 기초 연구)

  • 손건석;윤승원;고성혁;김대중;송재원;이귀영
    • Transactions of the Korean Society of Automotive Engineers
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    • v.10 no.2
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    • pp.40-47
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    • 2002
  • Because UV wavelength lights can activate photocatalysts, plasma is used as a light source of a photocatalytic reactor. Even though plasma has good intensity for photo reaction, substrate of catalyst coating was limited by the geometry of plasma generator. Usually bead type substrate was used for a pack bed type reactor. Honeycomb monolith type substrate was used with UV lamps instead plasma, due to the light penetration the honeycomb monolith length was too short to show good activity In this study a photocatalytic reactor, which is using a honeycomb monolith substrate, was investigated with plasma as an activation light source. As a parametric study the effects of 1311owing factors on plasma generation and power consumption are examined; supply voltage, substrate length, environment condition, catalyst loading and ratio. Using the test results, the practicability test was done with simulated synthetic gases representing bad smells and automotive exhaust gases.

Performance Evaluation of Hinge Driving Separation Nut-type Holding and Releasing Mechanism Triggered by Nichrome Burn Wire

  • LEE, Myeong-Jae;LEE, Yong-Keun;OH, Hyun-Ung
    • International Journal of Aeronautical and Space Sciences
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    • v.16 no.4
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    • pp.602-613
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    • 2015
  • As one of the mission payloads to be verified through the cube satellite mission of Cube Laboratory for Space Technology Experimental Project (STEP Cube Lab), we developed a hinge driving separation nut-type holding and releasing mechanism. The mechanism offers advantages, such as a large holding capacity and negligible induced shock, although its activation principle is based on a nylon cable cutting mechanism triggered by a nichrome burn wire generally used for cube satellite applications for the purpose of holding and releasing onboard appendages owing to its simplicity and low cost. The basic characteristics of the mechanism have been measured through a release function test, static load test under qualification temperature limits, and shock measurement test. In addition, the structural safety and operational functionality of the mechanism module under launch and on-orbit environments have been successfully demonstrated through a vibration test and thermal vacuum test.

The Electrical Characteristics of Amorphous $Te_{80}Se_{10}Sb_{10}$ Thin Film (비정질$Te_{80}Se_{10}Sb_{10}$ 박막의 전기적 특성)

  • 김흥석;이영종;정홍배
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1996.11a
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    • pp.238-241
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    • 1996
  • In this paper, we investigated the electrical characteristics which is d.c. and a.c. conductivity of the amorphous Te$_{80}$Se$_{10}$Sb$_{10}$thin film prepared by thermal evaporation. As the results, the d.c. conduction mechanism was followed thermally activated conduction and from the data of d.c. conductivity, the acti-vation energy and mobility gap were obtained. the d.c. conductivity was increased with temperature and a.c. conductivity also was increased with temperature and frequency. It can consider that the annealing is indispensable for higher conductivity since the activation energy decreased but d.c. and a.c. conductivity increased with annealing.aling.

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Low- Temperature Decomposition of Epoxy Resin

  • Katsuhiko Saido;Hiroyuki Taguchi;Yoichi Kodera;Takeshi Kuroki;Park, Jeong-Hun;Chung, Seon-Yong
    • Macromolecular Research
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    • v.12 no.5
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    • pp.490-492
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    • 2004
  • We report a new method using a heating medium for the thermal decomposition of epoxy resin (EP) at temperatures ranging from 50 to 200$^{\circ}C$. EP decomposition also occurred below 50$^{\circ}C$ during a 6-day period to generate bisphenol A (BPA) at concentrations as high as 5 ppm. When polyethylene glycol was used as a heating medium, we determined the kinetics of the EP decomposition at low temperature. We determined the apparent activation energy of the overall decomposition to be 40.8 kJ/mol and the frequency factor to be 2.3${\times}$10$^3$ by monitoring the rate of BPA formation. Thus, EP is clearly unstable upon the application of heat.

Activated Physical Properties at Air-Polymer Interface

  • Kajiyama, Tisato
    • Macromolecular Research
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    • v.15 no.2
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    • pp.109-113
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    • 2007
  • The surface molecular motion of monodisperse polystyrene (PS) films was examined using scanning vis-coelasticity microscopy (SVM) in conjunction with lateral force microscopy (LFM). The dynamic storage modulus, E', and loss tangent, $tan\delta$, at a PS film surface with number-average molecular weights, $M_n$, smaller than 30 k were found to be smaller and larger than those for the bulk sample, even at room temperature, meaning that the PS surface is in a glass-rubber transition or fully rubbery sate at this temperature when the $M_n$ is small. In order to quantitatively elucidate the dynamics of the molecular motion at the PS surface, SVM and LFM measurements were performed at various temperatures. The glass transition temperature, $T_g$, at the surface was found to be markedly lower than the bulk $T_g$, and this discrepancy between the surface and bulk became larger with decreasing $M_n$. Such an intensive activation of the thermal molecular motion at the PS surfaces can be explained in terms of an excess free volume in the vicinity of the film surface induced by the preferential segregation of the chain end groups.