• Bulletin of the Korean Chemical Society
• /
• v.30 no.2
• /
• pp.429-434
• /
• 2009

The OH($X^2{\Pi},\;{\nu}$"=0, 1) internal state distributions from the reaction of electronically ground state oxygen atoms with HSi$Cl_3$ were measured using laser-induced fluorescence. The ground-state O$(^3P_J)$ atoms with kinetic energies above the reaction barrier were produced by photolysis of N$O_2$ at 355 nm. The OH product revealed strong vibrational population inversion, P(${\nu}$"=1)/P(${\nu}$"=0) = 4.0 ${\pm}$ 0.6, and rotational distributions in both vibrational states exhibit substantial rotational excitations to the limit of total available energy. However, no preferential populations in either of the two $\Lambda$ doublet states were observed from the micropopulations, which supports a mechanism involving a direct abstraction of hydrogen by the atomic oxygen. It was also found that the collision energy between O and HSi$Cl_3$ is effectively coupled into the excitation of the internal degrees of freedom of the OH product ($$ = 0.62, and $<\;f_{rot}>$ = 0.20). The dynamics appear consistent with expectations for the kinematically constrained reaction which supports the reaction type, heavy + light-heavy $\rightarrow$ heavy-light + heavy (H + LH′ $\rightarrow$ HL + H′). The dynamics of oxygen atom collision with HSi$Cl_3$ are discussed in comparison to those with Si$H_4$.

• Journal of the Korean Institute of Gas
• /
• v.20 no.4
• /
• pp.65-77
• /
• 2016

Modeling for complex reacting flow in Fischer-Tropsch reactor is one of the challenges in the field of Computational Fluid Dynamics (CFD). It is hard to derive each and every reaction rate for all chemical species because Fisher-Tropsch reaction produces many kinds of hydrocarbons which include lots of isomers. To overcome this problem, after analyzing the existing methodologies for reaction rate modeling, non-Anderson-Schulz-Flory methodology is selected to model the detailed reaction rates. In addition, the inside flow has feature of multi-phase flow, and the methodologies for modeling multi-phase flow depend on the interference between the phases, distribution of the dispersed phase, flow pattern, etc. However, existing studies have used a variety of inside flow modeling methodologies with no basis or rationale for the feasibility. Modeling inside flow based on the experimental observation of the flow would be the best way, however, with limited resources we infer the probable regime of inside flow based on conventional fluid dynamics theory; select the appropriate methodology of Mixture model; and perform systematic CFD modeling. The model presented in this study is validated through comparisons between experimental data and simulation results for 10 experimental conditions.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2013.05a
• /
• pp.1515-1516
• /
• 2013

• 제어로봇시스템학회:학술대회논문집
• /
• 1989.10a
• /
• pp.395-398
• /
• 1989

A two dimensional pseudo-homogeneous model for the methanol reforming reaction was developed and its steady and dynamic states were studied by a computer simulation. The reactor tube diameter, the catalyst density in the fixed bed, the feed flow rate, the feed temperature and the external temperature were chosen to be adjusted to determine the length of the reactor. The dynamics of the reactor showed that the system was highly nonlinear and sensitive to the feed disturbances.

• 한국가시화정보학회:학술대회논문집
• /
• 2003.11a
• /
• pp.51-54
• /
• 2003

Fluid is an effective element in computer animation. Recently, the techniques from CFD have been actively applied to CG production. In this paper, we describe our fluid animation system which implements a variety of established simulation and rendering methods. We also explain our new techniques such as chemical reaction and hardware-assisted fluid animation that are being developed to enhance the features of our software system.

• Bulletin of the Korean Chemical Society
• /
• v.34 no.5
• /
• pp.1454-1456
• /
• 2013

The fluctuations in concentrations of reactants dominate the long-time dynamics of the single (A + A ${\rightarrow}$ 0) and two species (A + B ${\rightarrow}$ 0) diffusion-influenced annihilation reactions. Although hierarchical Smoluchowski approaches can provide a systematic and flexible framework to deal with the fluctuation effects, their results are too complicated to be analytically solved. For the efficient numerical calculation of the complicated fluctuation effect terms, we show that the presented point particle approximation is not only practical but also quite accurate for most conditions in diffusion-influenced reaction systems.

• Bulletin of the Korean Chemical Society
• /
• v.12 no.6
• /
• pp.692-698
• /
• 1991

The reaction path Smoluchowski equation approach developed in a recent work to calculate the rate constant for a diffusive multidimensional barrier crossing process is extended to incorporate the configuration-dependent diffusion matrix. The resulting formalism is then applied to the investigation of stilbene photoisomerization dynamics. Adapting a model two-dimensional potential and a model diffusion matrix proposed by Agmon and Kosloff [J. Phys. Chem.,91 (1987) 1988], we derive an eigenvalue equlation for the relaxation rate constant of the stilbene photoisomerization. This eigenvalue equation is solved numerically by using the finite element method. The advantages and limitations of the present method are discussed.

• Bulletin of the Korean Chemical Society
• /
• v.20 no.10
• /
• pp.1136-1144
• /
• 1999

The collision-induced reaction of gas-phase atomic hydrogen with hydrogen atoms chemisorbed on a silicon (001)-(2×1) surface is studied by use of the classical trajectory approach. The model is based on reaction zone atoms interacting with a finite number of primary system silicon atoms, which then are coupled to the heat bath, i.e., the bulk solid phase. The potential energy of the Hads‥Hgas interaction is the primary driver of the reaction, and in all reactive collisions, there is an efficient flow of energy from this interaction to the Hads-Si bond. All reactive events occur on a subpicosecond scale, following the Eley-Rideal mechanism. These events occur in a localized region around the adatom site on the surface. The reaction probability shows the maximum near 700K as the gas temperature increases, but it is nearly independent of the surface temperature up to 700 K. Over the surface temperature range of 0-700 K and gas temperature range of 300 to 2500 K, the reaction probability lies at about 0.1. The reaction energy available for the product states is small, and most of this energy is carried away by the desorbing H2 in its translational and vibrational motions. The Langevin equation is used to consider energy exchange between the reaction zone and the bulk solid phase.

• Bulletin of the Korean Chemical Society
• /
• v.27 no.10
• /
• pp.1659-1663
• /
• 2006

A many-body master equation is constructed by incorporating stochastic terms responsible for chemical reactions into the many-body Smoluchowski equation. Two forms of Langevin-type of memory equations describing the time evolution of dynamical variables under the influence of time-independent perturbation with an arbitrary intensity are derived. One form is convenient in obtaining the dynamics approaching the steady-state attained by the perturbation and the other in describing the fluctuation dynamics at the steady-state and consequently in obtaining the linear response of the system at the steady-state to time-dependent perturbation. In both cases, the kinetics of statistical averages of variables is found to be obtained by analyzing the dynamics of time-correlation functions of the variables.

• Proceedings of the KIEE Conference
• /
• 2008.10b
• /
• pp.325-326
• /
• 2008

서비스 로봇은 인간과 상호 교감을 하기 때문에 감성기반 인터렉션을 가지고 있어야 한다. 그리고 로봇이 인지하는 상황과 환경이 같을지라도 감정 기반 행동 결정 모델의 출력이 달라질수 있도록 한다. 이는 설계하고자 하는 감정 기반 행동 결정 모델의 특성을 변화함으써 해결하고자 하며, 감정 모델의 특성은 성격을 의미한다. 따라서 사람과 같이 성격을 달리함으로써 로봇이 감정을 느끼고 이에 따른 반응을 행동으로 옮길 때, 성격을 반영한 결과를 보이게 된다. 본 논문에서 제안하는 감정 엔진 모델은 reaction dynamics와 internal dynamics, emotional dynamics, behavior dynamics, 성격 등의 다섯 가지 요소로 구성되어 있다. 모든 dynamics는 성격에 영향을 받아 결과를 출력한다. 실험을 위하여 시뮬레이터를 구현하여 성능을 검증하고, 실제 로봇에 적용하기 위하여 3D 캐릭터기반의 헤드 로봇 시스템을 사용하였다.