• Title/Summary/Keyword: kinetic energy

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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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    • v.15 no.3
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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.

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

  • 서동표;오율권
    • Journal of Advanced Marine Engineering and Technology
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    • v.27 no.5
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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.

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

  • Seo, Dong-Pyo;Hong, Myung-Seok;Oh, Yool-Kwon
    • Proceedings of the KSME Conference
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    • 2003.04a
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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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Kinetic energy of Laminar Steady flows in the Exit Reguon Connected to the straight Square-sectionnal $180^{\circ}$ curved Duct by using PIV (PIV 계측에 의한 $180^{\circ}$곡관 출구에 연결된 직관에서 층류정상유동의 운동에너지)

  • Lee J.G.;Lee H.G.;Sohn H.C.;Lee H.N.;Park G.M.
    • Proceedings of the KSME Conference
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    • 2002.08a
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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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Implementation and the Energy Efficiency of the Kinetic Shading System (가동형 차양 시스템의 구성과 에너지 효율)

  • Han, Seung-Hoon
    • KIEAE Journal
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    • v.14 no.5
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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.

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

  • Kim, Dae-Soo
    • Journal of the Korean institute of surface engineering
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    • v.19 no.2
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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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Statistical Evaluation of Sigmoidal and First-Order Kinetic Equations for Simulating Methane Production from Solid Wastes (폐기물로부터 메탄발생량 예측을 위한 Sigmoidal 식과 1차 반응식의 통계학적 평가)

  • Lee, Nam-Hoon;Park, Jin-Kyu;Jeong, Sae-Rom;Kang, Jeong-Hee;Kim, Kyung
    • Journal of the Korea Organic Resources Recycling Association
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    • v.21 no.2
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    • pp.88-96
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    • 2013
  • The objective of this research was to evaluate the suitability of sigmoidal and firstorder kinetic equations for simulating the methane production from solid wastes. The sigmoidal kinetic equations used were modified Gompertz and Logistic equations. Statistical criteria used to evaluate equation performance were analysis of goodness-of-fit (Residual sum of squares, Root mean squared error and Akaike's Information Criterion). Akaike's Information Criterion (AIC) was employed to compare goodness-of-fit of equations with same and different numbers of parameters. RSS and RMSE were decreased for first-order kinetic equation with lag-phase time, compared to the first-order kinetic equation without lag-phase time. However, first-order kinetic equations had relatively higher AIC than the sigmoidal kinetic equations. It seemed that the sigmoidal kinetic equations had better goodness-of-fit than the first-order kinetic equations in order to simulate the methane production.

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

  • Yang, Hyun-Soo;Lim, Ju-Hun
    • Journal of the Korea Safety Management & Science
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    • v.10 no.2
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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.