• 제목/요약/키워드: thermal NO

검색결과 2,439건 처리시간 0.05초

저공해 스토커형 도시폐기물 소각로 설계를 위한 열유동 수치해석 연구 (The Study of Numerical Simulation on the Thermal Flow Performance for the Design of Low Emission Stoker Type Municipal Waste Incinerator)

  • 전영남;송형운;김미환
    • 한국환경과학회지
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    • 제11권6호
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    • pp.543-551
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    • 2002
  • A Numerical simulation on the thermal flow performance was carried out to propose the incinerator type for the domestic refuses and to investigate the design factor and operating conditions. The SSTI(Standard Stoker Type Incinerator) proposed in this study was modified from the type with central f)ow. It has the characteristics of good mixing between refuse and hot combustion gas in primary combustion chamber and between unburned gas inflowing and secondary air jet in secondary chamber. By predictive results, the SSTI was no recirculation zone in secondary chamber so that mixing time was increased with high residence time. It has good characteristics of combustion and low emission. Parametric screening studies have been understood with phenomenon of combustion in incinerator.

Fe-Ni Invar 합금 박막의 증착 및 박막 특성 평가 (Fabrication and characterization of fe-Ni Invar alloy thin films)

  • 김상섭;고영호;최장현;김병일;박용범
    • 한국진공학회지
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    • 제8권2호
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    • pp.116-120
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    • 1999
  • Fe-Ni alloy thin films with about 3.5 $\mu\textrm{m}$ thickness were successfully grown on Al-killed steel substrates employing DC magnetron sputtering method, and then the4 film properties were characterized. The deposited film exhibited a fibre texture structure with the relationship of ${110}_\textrm{film}//{111}_\textrm{substrate}$. We found that the adhesion between the film and the substrate was fairly good considering no debonding behavior after the thermal cyclic test of 5,000 times from room temperature to $200^{\circ}C$. Also we found that the Fe-Ni alloy deposition induced a significant decrease of thermal expansion in the film processing, a new material system with much lower thermal expansion coefficient which can be applied more as shadow mask materials than an Al-killed steel sheet.

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기판 삽입층을 갖는 팁 구조 탄소 나노튜브 이미터의 전계방출 특성 (Field emission properties of tip-type carbon nanotube emitters with substrate interlayer)

  • 장한빛;김종필;김부종;박진석
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2011년도 제42회 하계학술대회
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    • pp.1410-1411
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    • 2011
  • Tip-type carbon nanotube(CNT) based electron emitters were fabricated by forming a hafnium(Hf) interlayer between the CNT and the substrate. The CNTs were deposited by using the electrophoretic deposition method and thermally treated. No significant change in the microscopic structure of the CNTs, such as the ratio of length to diameter, was observed after the deposition of Hf interlayer and thermal treatment. As compared with the CNT emitter without the Hf-interlayer and thermal treatment, the CNT emitter with the Hf-interlayer and thermal treatment showed noticeably improved electron-emission properties due to the enhanced adhesion.

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환경변화에 의한 열 압착용 실리콘 고무의 정전기 대전 특성에 관한 연구 (A Study on Electrostatic Electrification Properties of Silicone Rubber for Thermal Bonding According to the Variation of Environment)

  • 이성일
    • 한국전기전자재료학회논문지
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    • 제23권9호
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    • pp.718-723
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    • 2010
  • In this paper, the following results were obtained from the experiment in which electrification voltage of silicone rubber specimen for thermal bonding were measured under various time, temperature ($10{\sim}40^{\circ}C$), and humidity (30~90%) conditions and different amount of carbon additives (0~15 phr (per hundred resin)). Electrostatics electrification voltage decreased when carbon is up to 10 phr, and there was no electrification voltage in 15 phr condition. The electrostatics electrification voltage did not change over time. When the temperature was constant, electrostatics electrification voltage sharply dropped when the humidity was around 70%. That means, this condition might be appropriate for prevention of charging. The electrification voltage decreased as humidity and amount of carbon increased.

345kV 인천화력 송전선로 철탑도괴 원인분석 및 대책 (345kV Overhead Transmission Line Collapse Analysis and Countermeasures)

  • 박재웅;신태우;최진성;최한열;민병욱
    • 전기학회논문지
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    • 제59권3호
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    • pp.531-535
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    • 2010
  • 345kV Incheon Thermal Power Plant Transmission Line Collapse Analysis and Countermeasures. The Typhoon Galmaegi which had been formed in July 15, 2008 diminished into a tropical cyclone and cooled the air above the West Sea. The cooled air colliding with the warm inland air caused a strong whirlwind at some places in the west seaside; the whirlwind battered the 345kV Incheon Thermal Power Plant Transmission Line to be collapsed. The resistance of transmission towers against wind pressure, one of the key elements in transmission line engineering, is designed to endure the pressure corresponding to the maximum instantaneous wind speed. Before the above accident happened, no transmission line has ever been collapsed by a whirlwind. So this paper is aimed to analyze causes that collapsed 345kV Incheon Thermal Power Plant transmission line and to introduce countermeasures.

345kV 인천화력 송전선로 철탑도괴 원인분석 및 대책 (Analysis and Countermeasures of 345kV Incheon-TP Overhead Transmission Lines Collapse)

  • 민병욱;신태우;최진성;최한열;박재웅
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2009년도 제40회 하계학술대회
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    • pp.323_324
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    • 2009
  • 345kV Incheon Thermal Power Plant Transmission Line Collapse Analysis and Countermeasures. The Typhoon Galmaegi which had been formed in July 15, 2008 diminished into a tropical cyclone and cooled the air above the West Sea. The cooled air colliding with the warm inland air caused a strong whirlwind at some places in the west seaside; the whirlwind battered the 345kV Incheon Thermal Power Plant Transmission Line to be collapsed. The resistance against wind pressure, one of the key elements in transmission line engineering, is designed to endure the pressure corresponding to the maximum instantaneous wind speed. Before the above accident happened, no transmission line has ever been collapsed by a whirlwind. So this paper is aimed to analyze causes that collapsed 345kV Incheon Thermal Power Plant transmission line and to introduce countermeasures.

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고능률 고속연삭에서 열원 모델에 관한 연구 (A Study on Heat Source Model to High Efficiency Speed Grinding)

  • 김남경
    • 한국공작기계학회논문집
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    • 제10권3호
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    • pp.1-6
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    • 2001
  • An analytical thermal model of HESG(higt efficiency speed grinding) is presented, in which the heat flux to workpiece in grinding zone is modeled as time dependent and moves along a slope decided by contact chord(approximation of con-tact arc). By matching the maximum surface temperature of workpiece derived from this model to the maximum surface temperature of grinding wheel composite as done in Lavins simple thermal model, the relation of maximum surface tem-perature and energy partition of workpiece to grinding speed is obtained. In high speed grinding, as wheel speed increases, energy partition decreases with no regard to table speed.

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A new model for transient heat transfer model on external steel elements

  • Chica, J.A.;Morente, F.
    • Steel and Composite Structures
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    • 제8권3호
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    • pp.201-216
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    • 2008
  • The Eurocode system provides limited information regarding the structural fire design of external steel structures. Eurocode 1 provides thermal action for external member but only in steady-state conditions. On the other hand, Eurocode 3 provides a methodology to determine heat transfer to external steelwork, but there is no distinction in cross section shapes and, in addition, the calculated temperature distribution is assumed to be uniform in the cross section. This paper presents the results of a research carried out to develop a new transient heat transfer model for external steel elements to improve the current approach of the Eurocodes. This research was carried out as part of the project EXFIRE "Development of design rules for the fire behaviour of external steel structures", funded by the European Research Programme of the Research Fund for Coal and Steel (RFCS).

Radiofrequency Thermal Ablation in Painful Myeloma of the Clavicle

  • Gharaei, Helen;Imani, Farnad;Vakily, Masoud
    • The Korean Journal of Pain
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    • 제27권1호
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    • pp.72-76
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    • 2014
  • A 57-year-old male patient had myeloma. He had severe pain in the left clavicle that did not respond to radiotherapy; therefore, it was treated with radiofrequency thermal ablation (RFTA). Under fluoroscopic guidance, two RF needles at a distance of 1.5 cm from each other were inserted into the mass and conventional radiofrequency ($90^{\circ}C$ and 60 seconds) at two different depths (1 cm apart) was applied. Then, 2 ml of 0.5% ropivacaine along with triamcinolone 40 mg was injected in each needle. The visual analogue pain score (VAS from 0 to 10) was decreased from 8 to 0. In the next 3 months of follow-up, the patient was very satisfied with the procedure and the mass gradually became smaller. There were no complications. This study shows that RFTA could be a useful method for pain management in painful osteolytic myeloma lesions in the clavicle

메탄 분류 화염에서의 연소 조건에 따른 NOx 배출 특성 (NOx Emission Characteristics in Parametrically Varied Methane-Air Coflow Flames)

  • 이상한;오창보;이창언
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2000년도 제20회 KOSCO SYMPOSIUM 논문집
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    • pp.35-44
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    • 2000
  • It was numerically studied that NOx emission characteristics of confined $CH_{4}$ jet flames with the variation of the diameter of inner fuel nozzle, the flow rate of $CH_{4}$ and equivalence ratio. Parabolic type equations were adopted in the calculation and GRI-2.1I mechanism was used for the chemical reaction. NOx emission index (EINOx) was introduced to evaluate NOx emission quantitatively in parametrically varied flames and the contribution of Thermal and Prompt NO mechanism was discussed. The results showed that Total EINOx varied sensitively with the variation of the flow rate of$CH_{4}$ but it was not sensitive to the variation of the diameter of inner fuel nozzle. Thermal EINOx showed the similar tendency to total EINOx and Prompt EINOx showed insensitivity to the variation of the diameter of inner fuel nozzle and the flow rate of $CH_{4}$.

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