• Title/Summary/Keyword: additional heat-treatment

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Improved Surface Morphologies of Printed Carbon Nanotubes by Heat Treatment and Their Field Emission Properties

  • Lee, Hyeon-Jae;Lee, Yang-Doo;Cho, Woo-Sung;Kim, Jai-Kyeong;Lee, Yun-Hi;Hwang, Sung-Woo;Ju, Byeong-Kwon
    • Journal of Information Display
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    • v.7 no.2
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    • pp.22-25
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    • 2006
  • This paper presents heating process for obtaining standing carbon nanotube emitters to improve field-emission properties from the screen-printed multiwalled carbon nanotube (MWCNT) films. In an atmosphere with optimum combination of nitrogen and air for heat treatment of CNT films, the CNT emitters can be made to protrude from the surface. This allows for high emission current and the formation of very uniform emission sites without special surface treatment. The morphological change of the CNT film by this technique has eliminated additional processing steps, such as surface treatment which may result in secondary contamination and damage to the film. Despite its simplicity the process provides high reproducibility in emission current density which makes the films suitable for practical applications.

Precipitation Behavior of α-Cr Particle in B2-type Intermetallic Compounds β-NiAl (B2형 금속간화합물 β-NiAl중에 α-Cr입자의 석출거동)

  • Han, Chang-Suck;Kim, Youn-Che
    • Journal of the Korean Society for Heat Treatment
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    • v.9 no.2
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    • pp.91-102
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    • 1996
  • Microstructural control to produce multiphase structure has received much attention to improve the high temperature strength as well as low temperature ductility of intermetallics. Transmission electron microscopic investigation has been carried out concerning the effect of Cr-precipitation on the mechanical properties of B2-ordered NiAl containing 4 to 8 mol% of Cr. By aging at temperatures around 973 K after solution annealing, fine spherical precipitates took place homogeneously in the NiAl matrix and the alloys hardened appreciably. Selected area electron diffraction (SAED) patterns have not revealed any additional extra-spots during aging, because the Cr-particles show cube-cube orientation relationship and keep a perfect coherency with the ordered matrix lattice. Dislocations were confirmed to bypass the particles during deformation. Although the dispersion of Cr-particles increased the yield strength of NiAl at intermediate temperature, the strength decreased appreciably at higher temperatures.

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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.

A Systematic Review of effect on Heat-sensitive Moxibustion for Benign Prostatic Hyperplasia (전립선비대증에 대한 열민구(熱敏灸)의 효과에 관한 체계적 문헌 고찰)

  • Kim, MinSeok;Ju, HongMin;Kim, MinHwa;Park, SunYoung;Yun, YoungJu;Park, SeongHa
    • The Journal of Korean Medicine
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    • v.42 no.3
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    • pp.153-164
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    • 2021
  • Objectives: The aim of this study is to investigate the effect of Heat-sensitive Moxibustion on Benign Prostatic Hyperplasia Methods: We searched articles from Academic Journals(CAJ) online databases, Oriental Medicine Advanced Searching Integrated System (OASIS), Searching key words were '前列腺增生', '熱敏灸' and '열민구', '전립선비대'. The search range included randomized controlled trials (RCTs). Among the articles published to 2020, 10 articles were found. After review the title, abstract and original, 3 articles were selected finally to rule out treatment combined with completely different treatments. Result: The Heat-sensitive moxibustion at acupoints in the treatment of Benign prostatic hyperplasia were significantly superior to control group after treatment in the symptoms of patients, IPSS, QOL, PVR and Qmax(P<0.05). The Heat-sensitive moxibustion can significantly reduce the incidence of temporary urinary incontinence after Transurethral resection of the prostate(TURP) and improve life quality and satisfaction of patients(P<0.05). The individualized desensitization saturated time and amount of Heat-sensitive moxibustion is superior effective to general amount and time of traditional moxibustion in the total effective rate, IPSS, Ru and Qmax(P<0.01) for Benign prostatic hyperplasia. Conclusion: Heat sensitive moxibustion directly transfer heat to the source of a disease. So it can be considered as a good treatment for Benign prostate hypertrophy. It was also shown a better effect on BPH compared to traditional moxibustion, According to the thermo principles of tumor, if the tumor cell's death temperature of 43℃ is reached, that can cause tumor degeneration. Therefore I think Heat sensitive moxibustion can be applied to various tumor disease. The results of this study could be applied to clinical treatment of BPH. However, additional large-scale clinical researches should be conducted.

Antigenicity Changes of Ovomucoid and Ovalbumin in Chicken Egg White by NaOH, Heat and Protease Tratments (NaOH, 열, 및 효소 처리에 의한 계란 난백 중 ovomucoid와 ovalbumin의 항원성 변화)

  • Ryu, Ju-Hyune;Park, Chun-Wuk;Lee, Jong-Mee;Shon, Dong-Hwa
    • Korean Journal of Food Science and Technology
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    • v.36 no.1
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    • pp.147-151
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    • 2004
  • Antigenicities of ovomucoid (OM) and ovalbumin (OA) in chicken egg white (EW) before and after NaOH, heat, and pretense treatments were examined by competitive indirect enzyme-linked immunosorbent assay (ciELISA), using rabbit anti-OM and-OA antibodies, Enzymatic hydrolysis of EW did not effectively reduce antigenicity of OM, whereas that of OA was decreased to 1/5,000-1/100,000 by treatment of plant-derived or microbial pretenses. Heat treatment below $100^{\circ}C$ for 30min did not decrease antigenicity of OM, whereas that of OA in heated EW increased maximally to 100 times, Antigenicity of OM in EW effectively decreased by NaOH treatment, disappearing at over 1% NaOH, whereas that of OA increased. Additional heat treatment of NaOH-treated EW at $70^{\circ}C$ for 15min slightly reduced antigenicities of OM and OA.

Improvement in the Color Fastness of Cotton Fabrics Dyed with Kale-Extracted Colorants (케일 추출 색소로 염색된 면직물의 염색견뢰도 향상)

  • Lee, Yeonjoo;Kwak, Sukyung;Jang, Jinho
    • Textile Coloration and Finishing
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    • v.31 no.4
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    • pp.225-232
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    • 2019
  • The colorants of kale powders were optimally extracted using an 1:1 mixture solvent of ethanol and DMSO at 105℃ for 30 minutes obtaining a high yield of 359.7㎍/mL chlorophylls. Low color fastness of the dyed fabrics with the extracts, particularly against washing and solar radiation, can be overcome by the combined treatments of chitosan, heat setting and tannic acid. Washing fastness to color change was improved from rating 1-2 up to 5 due to the enhanced electrostatic interactions between the colorants and the positive glucosamine unit of the chitosan in the cationized cotton. In addition, the tannic acid treatment contributed to the additional increase in color fastness after the sequential treatments of chitosan pretreatment, dyeing and heat setting.

Experimental Study on the Radiative and Convective Cooling of Electronic Modules opposed to a Heated Vertical Plate (가열 수직 평판과 마주보는 전자모듈의 복사 및 대류 냉각에 대한 실험적 고찰)

  • Choi, In-Su
    • Journal of the Korean Society of Industry Convergence
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    • v.8 no.2
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    • pp.105-112
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    • 2005
  • The characteristics of natural convection heat transfer combined with radiation in a vertical parallel plates has been investigated experimentally. The vertical channel is consisted with a heated wall and three protruding heating sources attached on the opposite wall. The cooling of modules has been experimented with heating the wall as well as modules themselves at different aspects ratios and heating fluxes. As the location of module is higher, the temperature becomes higher, but the increasement is smaller. When the aspect ratio is lower than 26, its effect on the temperature is not significant rather than that of the radiation heat transfer. Furthermore, the correlation of Nusselt number with the Rayleigh number are attempted, but additional treatment is needed to accomodate the cases of heating module and/or opposite wall.

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Effect of Additional Cu and Natural Aging Treatment on Thermal Diffusivity in the Al-Mg-Si Alloy (Al-Mg-Si 합금에서 Cu 첨가와 자연시효 열처리가 열확산도에 미치는 영향)

  • Kim, Yu-Mi;Choi, Se-Weon
    • Journal of Korea Foundry Society
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    • v.41 no.6
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    • pp.528-534
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    • 2021
  • To confirm effects of natural and artificial aging of precipitate on thermal diffusivity and hardness, the studied Al-Mg-Si alloy were manufactured by gravity casting method with 0.6 wt% and 1.0 wt% additional Cu element. The samples were used for measuring thermal diffusivity and hardness. The addition of Cu, promoted by intermediates such as Q'' and θ'' phases, contributing to the improvement of hardness and high-temperature thermal diffusivity. The natural aging decreased the hardness of the Al-Mg-Si-Cu alloys with increasing time, but did not affect the thermal diffusivity.

Analysis of Heat Transfer Performance of Oxi-nitriding Surface during Droplet Evaporation (산질화 표면에서의 액적 증발 열전달 성능 분석)

  • Kim, Dae Yun;Lee, Seong Hyuk
    • Journal of ILASS-Korea
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    • v.24 no.4
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    • pp.203-208
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    • 2019
  • In general, the oxi-nitriding method is well known as such a surface treatment way for substantial enhancement in corrosion resistance, even comparable to that of titanium. However, there are still lacks of information on thermal performance of the oxi-nitriding surface being of additional compound layers on the base substrate. Above all, the quantitative measurement of its thermal performance still was not evaluated yet. Thus, the present study experimentally measures the thermal resistance of the oxi-nitriding surface during droplet evaporation and then estimates heat transfer performance with the use of the onedimensional heat transfer model in vertical direction. From the experimental results, it is found that the total evaporation time slightly increased with the thermal resistance caused by the oxi-nitriding layer, showing a maximum difference of approximately 20% with that of the bare surface. Although the heat transfer performance of oxi-nitriding surface became slightly lower than that of the bare surface, the oxi-nitriding surface exhibits much better heat transfer performance compared to titanium.

Stabilization of Plasma in a Three-Phase AC Plasma Generator (삼상 교류 플라즈마 발생의 안정화)

  • Lee, K.H.;Kim, K.S.;Lee, H.S.;Rim, G.H.
    • Proceedings of the KIEE Conference
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    • 2002.11a
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    • pp.209-211
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    • 2002
  • A simple-structured thermal plasma generator for waste gas treatment has been studied. The thermal plasma technology applied to waste treatment has undoubtedly gained high importance owing to its outstanding properties such as flexibility, compact reactor, and clean treatment. Moreover, the thermal plasma generated by ac power has some additional advantages such as simple electrode system and easy maintenance. A prototype 200kW class plasma generator with specifications of 10-30m/sec gas velocity and 3000-5000K temperature on the center just outside of the nozzle has been designed and tested. Case studies on heat transfer, heat flow, velocity distribution, and temperature distribution using a commercial simulation package show lots of flexibility in design. The experimental results from theprototype generator show that the ac thermal plasma is easily controlled by working gas flow once it is ignited. A stabilization condition is discussed with the data from monitoring arc voltage drops with respect to gas flow rate during the test.

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