• Bulletin of the Korean Chemical Society
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• v.29 no.3
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• pp.641-646
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• 2008

Equilibrium molecular dynamics simulations in a canonical ensemble are performed to evaluate the transport coefficients of several Lennard-Jones (LJ) mixtures at a liquid argon states of 94.4 K and 1 atm via modified Green-Kubo formulas. Two component mixture of A and B is built by considering the interaction between A and A as the attractive (A) potential, that between A and B as the attractive potential (A), and that between B and B as the repulsive potential (R), labelled as AAR mixture. Three more mixtures - ARA, ARR, and RAR are created in the same way. The behavior of the LJ energy and the transport properties for all the mixtures is easily understood in terms of the portion of attractive potential (A %). The behavior of the thermal conductivities by the translational energy transport due to molecular motion exactly coincides with that of diffusion constant while that of the thermal conductivities by the potential energy transport due to molecular motion is easily understood from the fact that the LJ energy of AAR, ARR, and RAR mixtures increases negatively with the increase of A % from that of the pure repulsive system while that of ARA changes rarely.

• Journal of Ocean Engineering and Technology
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• v.27 no.5
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• pp.99-104
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• 2013

Recently, various nanoparticles have been used for filler in polymer matrices. The particles of nano size are whether high or not cross-link density in polymer affects the thermal and mechanical properties of one. The properties change as a result of chemical reactions between the nanoparticles and the surface of the polymer. There are two models for nanocomposites: "repulsive interaction" and "attractive interaction" between the nanoparticles and matrix. In this study, the variation in the curing mechanism was examined when nano-size $TiO_2$ was dispersed into an epoxy (Bisphenol A, YD-128) with different curing agents. The results of this study showed that the exothermic temperature and Tg in the case of the nanoparticles used (Jeffamine) (D-180) at room temperature were reduced by an increase in the $TiO_2$ contents because of the "repulsive interaction" between the nanoparticles and the matrix. The tensile strengths were increased by increasing amounts of $TiO_2$ until 3 wt% because of a dispersion strengthening effect caused by the nanoparticles, because of the repulsive interaction. However, such tensile properties decreased at 5 wt% of $TiO_2$, because the $TiO_2$ was agglomerated in the epoxy. In contrast, in the case of the nanoparticles that used NMA and BDMA, the exothermic temperature and Tg tended to rise with increasing amounts of $TiO_2$ as a result of the "attractive interaction." This was because the same amounts of $TiO_2$ were well dispersed in the epoxy. The tensile strength decreased with an increase in the $TiO_2$ contents. In the general attractive interaction model, however, the cross-link density was higher, and tensile strength tended to increase. Therefore, for the nanoparticles that used NMA, it was difficult to conclude that the result was caused by the "attractive model."

• Journal of the Korean Ceramic Society
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• v.14 no.4
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• pp.226-229
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• 1977

The infrared absorption spectrum of Synthesized magnesite is shown in the wve number region 2510 and 745cm-1. By using Wilson's GF matrices the force constants' of the Urey-Bradley force field were deterined from the infrared absorption frequencies. For magnesite the stretching force constant K=5.41, the bending force constant H=0.46, the repulsive force constant F=1.97, and the force constant for the out-of-plane vibration fθ=0.65md/Å. For calcite they are K=5.51, H=0.38, F=1.88 and fθ=0.64md/Å.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.1101-1102
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• 2010

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.658-662
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• 1991

In this paper, a real-time obstacle avoidance for mobile robot based on the readings of the ultrasonic sensors is presented. The twenty eight ultrasonic sensors are arranged in ring and controlled by microprocessor. The readings of the ultrasonic sensor is converted into the virtual forces called repulsive forces, which are the elastic and damping forces. Then, the direction and speed of mobile robot in the cluttered environment are determined by the virtual forces. The effectiveness of the proposed method is verified from a series of simulation studies.

• Proceedings of the KIEE Conference
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• 2002.04a
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• pp.18-20
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• 2002

In this paper, various forces generated in the Gas Circuit Breaker(GCB) such as operating force, repulsive force, spring force, and dashpot force are analyzed with the fluid properties and the mechanical structure. The operation of GCB can be understood. A stroke curve from the result of simulation is compared with experimental one.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.101-103
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• 2001

Suspension effect has been studied by using superconductor of BiPbSrCaCuO ceramics containing Ag$_2$O It has been cleared that Ag$_2$O acts as pinning center which plays an important role to the suspension effect. Magnetic repulsive force which affects a superconductor located in magnetic flux from toroidal magnet has been investigated. It has been concluded that the suspension effect arises from the interaction between the pinning effect and the diamagnetic effect.

• Journal of Electrical Engineering and Technology
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• v.11 no.5
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• pp.1253-1264
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• 2016

• Proceedings of the KIEE Conference
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• 2002.11a
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• pp.69-70
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• 2002

Suspension effect has been studied by using superconductor of BiPbSrCaCuO ceramics containing $Ag_2O$. It has been cleared that $Ag_2O$ acts as pinning center which plays an important role to the suspension effect. Magnetic repulsive force which affects a superconductor located in magnetic flux from toroidal magnet has been investigated. It has been concluded that the suspension effect arises from the interaction between the pinning effect and the diamagnetic effect.

• Proceedings of the Korean Biophysical Society Conference
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• 1997.07a
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• pp.35-35
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• 1997

We model the voltage-gated cation channel on the basis of stochastic process by taking into account transmembrane movement of S4 group interacting electrostatically with permeant ions. It is assumed that the interaction between the ion and S4 group is repulsive harmonic force and the ionic motion is much faster than that of the S4 group.(omitted)