• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.649-652
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• 2005

It is reported that semi-solid forming process takes many advantages over the conventional forming process, such as long die lift, good mechanical properties and energy saves. Rheology material has a thixotropic, pseudo-plastic and shear-thinning characteristic. Therefore, general plastic or fluid dynamic analysis is not suitable for the behavior of rheology material. So it is difficult for a numerical simulation of the rheology process to be performed because complicated processes such as the filling to include the state of the free surface and solidification in the phase transformation must be considered. Moreover, it is important to predict the deformation behavior for optimization of net shape forging process with semi-solid materials and to control liquid segregation for mechanical properties of materials. In this study, so, molecular dynamics simulation was performed for the control of liquid segregation in compression experiment as a part of study on analysis of rheology forming process.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1337-1340
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• 2005

A rheology casting technology has some advantages compared with conventional forming processes such as die casting, squeeze casting and hot/cold forming. The liquid segregation is important on mechanical properties of materials using rheology casting. In this study, so, molecular dynamics simulations were performed for the control of liquid segregation. Because the dynamics of fluid flow about nano-scaled materials is completely different from continuum, molecular dynamics simulations were used. The behavior of particles was far from the truth according to boundary conditions in simple flow. But various movement of particles appear at two or more molecular simulations.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.774-777
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• 2004

A rheology casting technology has some advantages compared with conventional forming processes such as die casting, squeeze casting and hot/cold forming. The liquid segregation is important on mechanical properties of materials using rheology casting. In this study, so, molecular dynamics simulations were performed for the control of liquid segregation. Because the dynamics of fluid flow about nano-scaled materials is completely different from continuum, molecular dynamics simulations were used. The behavior of particles was far from the truth according to boundary conditions in simple flow. But various movement of particles appear at two or more molecular simulations.

• Journal of Korean Neurosurgical Society
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• v.44 no.6
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• pp.382-384
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• 2008

Gas forming brain abscess is a rare disease caused by Klebsiella pneumoniae occurring in patients with impaired host defense mechanism such as diabetes mellitus or liver cirrhosis. A 59-year-old man with 2-year history of diabetes mellitus and 20-year history of liver cirrhosis presented to the hospital with headache. On the day after admission, severe headache was developed and he deteriorated rapidly. Brain CT showed a non-enhanced mass including multiple air density as well as surrounding edema seen in the right occipital lobe, and isodensity air-fluid level seen in the right lateral ventricle. Despite emergent ventricular drainage and intraventricular and intravenous administration of antibiotics, his condition progressively worsened to sepsis and to death after 5 days. Bacterial culture of blood and ventricular fluids disclosed a Gram (-) rod, Klebsiella pneumoniae. In this report we review the pathogenic mechanism and its management.

• Progress in Superconductivity
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• v.8 no.1
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• pp.104-107
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• 2006

For the practical application on SCFCL(Superconducting fault current limiters), Bi-2212 tubes were fabricated by Centrifugal Forming Process(CFP). The tubes were annealed at 830, 840, $850^{\circ}C$, respectively for 80 hours in oxygen atmosphere. The tubes heat treated at $840^{\circ}C$ demonstrated better electric characteristics than the tubes heat treated at 830 and $850^{\circ}C$. The typical value measured at 77 K in the self field was around 556 A. In terms of cooling effect on superconducting properties, it was found the electrical properties were quite dependent on the mold design and shapes. In order to check uniformity along the tube, EFDLab fur heat and fluid analysis of NIKA was adopted. It was found out that the simulation data was quite well matched with experimental results.

• Journal of the Semiconductor & Display Technology
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• v.9 no.3
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• pp.29-34
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• 2010

Nanoimprint lithography (NIL) is an emerging technology enabling cost effective and high throughput nanofabrication. To successfully imprint a nanometer scale patterns, the understanding of the mechanism in nanoimprint forming is essential. In this paper, a numerical analysis of polymer flow in thermal NIL was performed. First, a finite element model of the periodic mold structure with prescribed boundary conditions was established. Then, the volume of fluid (VOF) and grid deformation method were utilized to calculate the free surfaces of the polymer flow based on an Eulerian grid system. From the simulation, the velocity fields and the imprinting pressure for constant imprinting velocity in thermal NIL were obtained. The velocity field is significant because it can directly describe the mode of the polymer deformation, which is the key role to determine the mechanism of nanoimprint forming. Effects of different mold shapes and various thicknesses of polymer resist were also investigated.

• Parasites, Hosts and Diseases
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• v.30 no.3
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• pp.209-218
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• 1992

When cystic fluid of Taenia solium metacestodes (CF) was filtrated through Sephacryl S-300 Superfine, major proteins were in fractions III add IV Major protein in fraction III was Band C protein of 150 kDa and that in fraction IV was Band N protein (Choi et of., 1990). When CF was electrophoresed in 0.9% agarose gel and reacted with anti-CF rabbit serum (RACF), two main bands, a long outer and a short inner band, were precipitated, together with 8 minor bands. RACF reacted with fraction III forming the long outer band whereas RACF formed the short infer band with fraction IV in immunoelectrophoresis (IEP) The long outer precipitin band of CF fraction III was similar to antigen B in hydatid fluid (HF) of Oriol et at. (1971), while the short inner band of CF fraction IV was similar to HF antigen 5 of Caption et at. (1967) . When HF was reacted with RACF, the short inner band was immunoprecipitated without forming the long outer band. Common antigenicity between CF and HF seemed to exist in fraction IV rather than in fraction III of CF. Patient sera of neurocysticercosis reacted more frequently with fraction III than with fraction IV.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.1888-1893
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• 2007

In this study, the microchannel plated heat exchanger were numerically studied for the enhancement of heat transfer in the channel configuration. Unit cold and hot fluid region with the microchannel were modeled and periodic boundary condition at the side wall was applied to continuously repeating geometry. The material of micro-structured plate is STS304 and working fluid is water. Triangular obstacles were placed in micro channel to enhance heat transfer. The performance of microchannel plated heat exchangers were numerically investigated with various obstacle configuration and Reynolds number under the parallel and counter flows. Heat transfer rate has increased about 18% compared with straight channel, but pressure drop also increased about 3.5 times. The main factor of increasing of pressure drop and heat transfer rate is considered that the momentum was lost to collide against obstacles, generation of secondary flow and boundary layer separation, wake and vortex forming phenomena.

• Korea-Australia Rheology Journal
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• v.18 no.2
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• pp.41-49
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• 2006

A modified Volume-of-Fluid (VOF) numerical method is used to predict the dynamics of a liquid drop of a low viscosity dilute polymer solution, forming in air from a circular nozzle. Viscoelastic effects are rep-resented using an Oldroyd-B model. Predicted drop shapes are compared with experimental observations. The main features, including the timing of the shape evolution and the 'bead-on-a-string' effect, are well reproduced by the simulations. The results confirm published conclusions of the third author, that the deformation is effectively Newtonian until near the time of Newtonian pinch-off and that the elastic stress becomes large in the pinch region due to the higher extensional flow there.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2006.11a
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• pp.407-410
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• 2006

This study describes a simulation of two-dimensional bubble forming and motion by the Lattice Boltzmann Method with the phase field equation. The free energy model is used to treat the interfacial force and deformation of binary fluids system, drawn into a T-junction the micro channel. A numerical simulation of a binary flow in a cross-junction channel is carried out by using the parallel computation method. The aim in this investigation is to examine the applicability of LBM to numerical analysis of binary fluid separation and motion in the micro channel.