• 제목/요약/키워드: kinetic energy

검색결과 1,855건 처리시간 0.032초

Determination of the Kinetic Energy Release Originating from the Reverse Critical Energy in Unimolecular ion Dissociation

  • Yeh, In-Chul;Lee, Tae-Geol;Kim, Myung-Soo
    • Bulletin of the Korean Chemical Society
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    • 제15권3호
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    • pp.241-245
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    • 1994
  • A method has been developed to estimate the kinetic energy release originating from the reverse critical energy in unimolecular ion dissociation. Contribution from the excess energy was estimated by RRKM theory, the statistical adiabatic model and the modified phase space calculation. This was subtracted from the experimental kinetic energy release distribution (KERD) via deconvolution. The present method has been applied to the KERDs in $H_2$, loss from $C_6H_6^+$ and HF loss from ${CH_2CF_2}^+$. In the present formalism, not only the energy in the reaction coordinate but also the energy in some transitional vibrational degrees of freedom at the transition state is thought to contribute to the experimental kinetic energy release. Details of the methods for treating the transitional modes are found not to be critical to the final outcome. For a reaction with small excess energy and large reverse critical energy. KERD is shown to be mainly governed by the reverse critical energy.

영상기법을 이용한 수직상향 기포유동에 관한 연구 (A Study on the Vertical upward Bubble Flow using Image Processing Technique)

  • 서동표;오율권
    • Journal of Advanced Marine Engineering and Technology
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    • 제27권5호
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    • pp.617-623
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    • 2003
  • In the present study, the characteristics of upward bubble flow were experimentally investigated in a liquid bath. The velocity of upward bubble flow was calculated for two different experimental conditions:1) bubble flow without kinetic energy 2) bubble flow with kinetic energy. Bubble flow without kinetic energy starts to undergo the effect of buoyancy l0cm away from the nozzle. Whereas. kinetic energy is dominant before 30 cm away from the nozzle in bubble flow but after this point kinetic energy and inertial force are applied on bubble flow at the same time In addition, as the flow rate increases the maximum velocity point moves to the nozzle. The velocity Profiles near free surface is extremely irregular due to surface flow. Gas volume fraction is high near the nozzle due to gas concentration. but decreases with the increasement of axial position. Gas volume fraction does not vary after the axial position, z=60 in spite of the increasement of flow.

기-액 기둥에서 기포유동에 관한 연구 (A Study on the Bubble Flow in the Gas-Liquid Plume)

  • 서동표;홍명석;오율권
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 춘계학술대회
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    • pp.2105-2108
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    • 2003
  • The characteristics of upward bubble flow were experimentally investigated in a liquid bath. In the present study, a thermal-infrared camera and high speed CCO camera were used to measure their temperature and local rising velocity, respectively. Heat transfer from bubble surface to water is largely completed within z=10mm from the nozzle, and then the temperature of bubble surface reaches that of water rapidly. The rising velocity of bubble was calculated for two different experimental conditions: 1) bubble flow without kinetic energy 2) with kinetic energy. Bubble flow without kinetic energy starts to undergo the effect of inertia force 10cm away from the nozzle. Whereas, kinetic energy is dominant before 30 cm away from the nozzle in bubble flow, but after this point, kinetic energy and inertial force are applied on bubble flow at the same time.

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PIV 계측에 의한 $180^{\circ}$곡관 출구에 연결된 직관에서 층류정상유동의 운동에너지 (Kinetic energy of Laminar Steady flows in the Exit Reguon Connected to the straight Square-sectionnal $180^{\circ}$ curved Duct by using PIV)

  • 이종구;이홍구;손현철;이행남;박길문
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2002년도 학술대회지
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    • pp.521-524
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    • 2002
  • In the present study, kinetic energy of laminar steady flow in the exit region connected to the square-sectional $180^{\circ}$curved duct was investigated experimentally. The experimental study for air flows was conducted to measure kinetic energy distributions by using the Particle Image Velocimetry(PIV) system with the data acquisition and processing system of Cactus 2000 software. The results obtained from experimental studies are summarized as follows : (1) The critical Reynolds number for a change from laminar steady flow to transitional steadt flow was about 1910, in the 50 region of dimensionless axial position (x/Dh) whirh was considered as a fully developed flow region. (2) Maximum kinetic energy of laminar steady flow was gradually increased as the Reynolds number increased.

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가동형 차양 시스템의 구성과 에너지 효율 (Implementation and the Energy Efficiency of the Kinetic Shading System)

  • 한승훈
    • KIEAE Journal
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    • 제14권5호
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    • pp.67-73
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    • 2014
  • This study aims at examining kinetic efficient shading systems and their implementation methods. These days, the importance of the shading devices are getting more significant due to the energy problem. Cordially, suitable shade designs are required as an important element for the exterior envelope of the building. This study employs the optimal shading design as an efficient shading method with the kinetic system that can be converted actively by the altitude of the sun. The proposed kinetic shading system works not only as a lightshelf in case the altitude of the sun is high but also as a vertical louver when the sun is getting lower in order to block the direct sunlight. This study has analyzed the thermal performance and shading coefficient of the kinetic shading system in comparison to existing fixed shading devices using the Ecotect. The results, in sum, conclude that the suggested kinetic shading system could decrease direct sunlights 26.2% more than the existing shading methods.

眞空 蒸着에 관한 速度論的 모델 (Kinetic Model on the Vacuum Deposition)

  • 김대수
    • 한국표면공학회지
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    • 제19권2호
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    • pp.51-58
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    • 1986
  • A theoretical model was proposed to predict the rate of particles impinging on the negatively biased substrate and the total kinetic energy per unit time. The model takes into an account of kinetic theory based on Maxwell statistics and elementary plasma theory, incorporated with Hertz-Knudsen's evaporation theory. It is found that as the bias potential increases the ion flux and kinetic energy increases to a value above which the effect of potential is insignificant.

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폐기물로부터 메탄발생량 예측을 위한 Sigmoidal 식과 1차 반응식의 통계학적 평가 (Statistical Evaluation of Sigmoidal and First-Order Kinetic Equations for Simulating Methane Production from Solid Wastes)

  • 이남훈;박진규;정새롬;강정희;김경
    • 유기물자원화
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    • 제21권2호
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    • pp.88-96
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    • 2013
  • 본 연구의 목적은 고형폐기물의 메탄발생 특성을 나타내기 위한 1차 반응식과 S형태 식들의 적합성을 평가하는 것이다. S형태 식은 수정 Gompertz와 Logistic 식을 사용하였다. 모델의 적합성을 평가하기 위해 잔차제곱합, 표준제곱근 오차, Akaike's information criterion 등의 통계분석을 실시하였다. AIC (Akaike's information criterion)는 모델의 변수 개수 차이에 따른 모델 적합성을 비교하기 위하여 적용하였다. 1차 반응식의 경우 지체기를 고려하지 않을 때보다 고려하였을 경우 잔차제곱합과 표준제곱근 오차는 감소하는 것으로 나타났다. 그러나 1차 반응식의 경우 S형태 식보다 AIC가 상대적으로 높게 나타났다. 이는 S형태 식이 1차 반응식보다 메탄발생특성을 나타낼 때에 더욱 적합한 것으로 사료된다.

압축비에 의한 엔진 출력 변화 특성 (The Compression Ratio Change Characteristics of Engine Horse Power Characteristics)

  • 양현수;임주헌
    • 대한안전경영과학회지
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    • 제10권2호
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    • pp.85-94
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    • 2008
  • The object of this study is to investigate the penetration characteristics according to the change of stacking sequences and curvature radius in the composite laminated shell. They are staked to [02/902]S and [0/902/0]s, their interlaminar number are two and four. We are manufactured to composite laminated shells with various curvature radius. Curvature radius of composite shell is 100, 150, 200mm and ${\infty}$(it's meaning flat-plate). In general, kinetic energy after impact-kinetic energy before impact increased linearly in all specimens. Absorbed energy increased linearly as the curvature increased, and absorbed energy of [02/902]S specimen, which is small interlaminar number, was higher than [0/902/0]s specimen.