• Korean Chemical Engineering Research
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• v.46 no.3
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• pp.604-609
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• 2008

This study is about the modeling and simulation of heat transfer in the box for packaging and shipping of vaccines. Comparison of the simulation results with experimental data revealed that a one-dimensional model (a spherical model of using a radius equivalent to the rectangular geometry of box) showed good agreement with experimental data during cooling process but did not successfully simulate heating process. It is considered that a rigorous boundary condition is not properly applied for outer surface of the box. However, we could successfully develop a basic algorithm for simulating heat transfer through multi-slabs combined with different materials including phase change material.

• Solar Energy
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• v.18 no.3
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• pp.95-105
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• 1998

In this study, basic design data which were required for development of highly efficient ice storage system with low temperature latent heat were experimentally obtained. The ice storage system considered in this study was the one that has been widly used in the developed country and called the ice-on-coil type. Using the system, the ice storage performance for various design parameters which were the flow direction and the inlet temperature of the secondary fluid was tested. In addition, the timewise variation of the interface profiles between the solid and the liquid were visualized, and the heat transfer characteristics of the Phase Change Material(PCM) in the ice storage tank were Investigated. During the freezing processes in the ice storage tank with several vertical tubes, decrease of the heat transfer area and the heat resistance of the ice layer made the increasing rate of ice packing factor(IPF) less. The total freezing energy for the upward flow of the secondary fluid was higher than that for the downward flow. The average ice storage efficiency for the upward flow of the secondary fluid was higher than that for the downward flow.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.857-858
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• 2006

Estrangement hierarchical by bipolarization is deepened and time space that social welfare by graying corresponds great so. Specially, is real condition that indifference by patient's increase which is solitary life string is come to involve by social problem. Together, Jaetaek bone fracture patient's ratio is zooming. Domestic BT technology, medical treatment solution technology offer more important role than role assistance enemy of modern technology and utilize by creative technology can . Specially, if apply supersonic waves in bone fracture treatment, there is treatise data that can reduce bone fracture treatment period of bone that bone does not stick well about 40%. Supersonic waves operation frequency used on both end because do 1m Hz, 1.3mHz, supersonic waves origination that have 1.5mHz's Piezo-ceramic crystal tranducer material each 4 premature senilitys in this research, and outside diameter according to impedance and Phase d used Gakgak4mm, 5.4mm, Dukke0.5mm, transformer deuce of length 70mm. Manufactured, and investigated supersonic waves distribution chart by capacity 50m W. Supersonic waves used by diagnosis mainly but is seen to become convenient medical treatment mounting in bone fracture patient's treatment if supplement clinically. If supplement system furthermore, is going to apply to osteoporosis patient, and this research tried to design poetic theme width directly and study rain standardization special quality and approach basic form because do modelling.

• Korean Journal of Materials Research
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• v.30 no.11
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• pp.627-635
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• 2020

3D printing technology is a processing technology in which 3D structures are formed by fabricating multiple 2D layers of materials based on 3D designed digital data and stacking them layer by layer. Although layers are stacked using inkjet printing to release various materials, it is still rare for research to successfully form a product as an additive manufacture of multi-materials. In this study, dispersion conditions are optimized by adding a dispersant to an acrylic monomer suitable for inkjet printing using Co₃O₄ and Al₂O₃. 3D structures having continuous composition composed of a different ceramic material are manufactured by printing using two UV curable ceramic inks whose optimization is advanced. After the heat treatment, the produced structure is checked for the formation and color of the desired crystals by comparing the crystalline analysis according to the characteristics of each part of the structure with ceramic pigments made by solid phase synthesis method.

• Geomechanics and Engineering
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• v.13 no.5
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• pp.809-823
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• 2017

This paper describes lab test results of artificial rock-like material samples having a plane joint. Cyclic shear tests were performed under different normal loads and different shear displacement amplitudes. For this purpose, multi-stage normal loading tests (30 kN, 60 kN, 90 kN, 180 kN, 360 kN and 480 kN) with cyclic excitation at frequency of 1.0 Hz and different shear displacement amplitudes (0.5 mm, 1.0 mm, 2.0 mm, 4.0 mm, 5.0 mm, and 8.0 mm) were conducted using the big shear box device GS-1000. Experimental results show, that shear forces increase with the increase of normal forces and quasi-static friction coefficient is larger than dynamic one. With the increase of normal loads, approaching the peak value of shear forces needs larger shear displacements. During each cycle the normal displacements increase and decrease (rotational behavior in every cycle). Peak angle of inclination increases with the increase of normal load. A phase shift between maximum shear displacement and maximum shear force is observed. The corresponding time shift decreases with increasing normal load and increases with increasing shear displacement amplitudes.

• Advances in concrete construction
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• v.16 no.2
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• pp.107-117
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• 2023

Textile-reinforced concrete composite (TRC) is a new alternative material that can satisfy sustainable development needs in the civil engineering field. Its mechanical behaviour and properties have been identified from the experimental works. However, it is necessary for a numerical approach to consider the effect of the parameters on TRC's behaviour with lower analysis duration and cost related to the experiment. This paper presents obtained results of the numerical modelling for TRC composite using the cracking model for the cementitious matrix in TRC. As a result, the TRC composite exhibited a strain-hardening behaviour with the cracking phase characterized by the drops in tensile stress on the stress-strain curve. This model also showed the failure mode by multi-cracking on the TRC specimen surface. Furthermore, the parametric studies showed the effect of several parameters on the TRC tensile behaviour, as the reinforcement ratio, the length and position of the deformation measurement zone, and elevated temperatures. These numerical results were compared with the experiment and showed a remarkable agreement for all cases of this study.

• Transactions of the Korean hydrogen and new energy society
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• v.24 no.5
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• pp.367-372
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• 2013

Hydrogen storage as a metal hydride is the most promising alternative because of its relatively large hydrogen storage capacities near room temperature. TiMn2-based C14 Laves phases alloys are one of the promising hydrogen storage materials with easy activation, good hydriding-dehydriding kinetics, high hydrogen storage capacity and relatively low cost. In this work, multi-component, hyper-stoichiometric $Ti_{0.85}Zr_{0.13}(Fe_x-V)_{0.56}Mn_{1.47}Ni_{0.05}$ C14 Laves phase alloys were prepared by a vacuum induction melting for a hydrogen storage tank. Since pure vanadium (V) is quite expensive, the substitution of the V element in these alloys has been tried and some interesting results were achieved by replacing V by commercial ferrovanadium (FeV) raw material. In addition, the melt-spinning process, which was applied to the manufacturing of some of these alloys, could make the plateau slopes much flatter, which resulted in the increase of reversible hydrogen storage capacity. The improvement of sloping properties of melt-spun $Ti_{0.85}Zr_{0.13}(Fe_x-V)_{0.56}Mn_{1.47}Ni_{0.05}$ alloys was mainly attributed to the homogeneity of chemical composition.

• Journal of the Korea Computer Industry Society
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• v.7 no.3
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• pp.245-252
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• 2006

Estrangement hierarchical by bipolarization is deepened and time space that social welfare by graying corresponds great so. Specially, is real condition that indifference by patient's increase which is solitary life string is come to involve by social Voblem. Together, Jaetaek bone fracture patient's ratio is zooming. <중략>Supersonic waves operation frequency used on both end because do 1mHz, 1.3mHz, supersonic waves origination that have 1.5mHz's Piezo-ceramic crystal tranducer material each 4 premature senilitys in this research, and outside diameter according to impedance and Phase d used Gakgak4mm, 5.4mm, Dukke0.5mm, transformer deuce of length 70mm. Manufactured, and investigated supersonic waves distribution chart by capacity 50m W. Supersonic waves used by diagnosis mainly but is seen to become convenient medical treatment mounting in bone fracture patient's treatment if supplement clinically. If supplement system furthermore, is going to apply to osteoporosis patient, and this research tried to design poetic theme width directly and study rain standardization special qualify and approach basic form because do modelling.

• Journal of Ginseng Research
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• v.39 no.2
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• pp.125-134
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• 2015

Background: Black ginseng (Ginseng Radix nigra, BG) refers to the ginseng steamed for nine times and fine roots (hairy roots) of that is called fine black ginseng (FBG). It is known that the content of saponin of FBG is higher than that of BG. Therefore, in this study, we examined antitumor effects against MCF-7 breast cancer cells to target the FBG extract and its main component, ginsenoside Rg5 (Rg5). Methods: Action mechanism was determined by MTT assay, cell cycle assay and western blot analysis. Results: The results from MTT assay showed that MCF-7 cell proliferation was inhibited by Rg5 treatment for 24, 48 and 72 h in a dose-dependent manner. Rg5 at different concentrations (0, 25, 50 and $100{\mu}M$), induced cell cycle arrest in G0/G1 phase through regulation of cell cycle-related proteins in MCF-7 cells. As shown in the results from western blot analysis, Rg5 increased expression of p53, $p21^{WAF1/CIP1}$ and $p15^{INK4B}$ and decreased expression of Cyclin D1, Cyclin E2 and CDK4. Expression of apoptosiserelated proteins including Bax, PARP and Cytochrome c was also regulated by Rg5. These results indicate that Rg5 stimulated cell apoptosis and cell cycle arrest at G0/G1 phase via regulation of cell cycle-associated proteins in MCF-7 cells. Conclusion: Rg5 promotes breast cancer cell apoptosis in a multi-path manner with higher potency compared to 20(S)-ginsenoside Rg3 (Rg3) in MCF-7 (HER2/ER+) and MDA-MB-453 (HER2+/ER) human breast cancer cell lines, and this suggests that Rg5 might be an effective natural new material in improving breast cancer.

• Advances in concrete construction
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• v.1 no.3
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• pp.239-252
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• 2013

Mortar microstructure is considered as a three-phase composite material, which is cement paste, fine aggregate and interfacial transition zone. Interfacial transition zone is the weakest link between the cement paste and fine aggregate, so it has a significant role to determine the properties of cementitious composites. In this study, specimens (w/c = 0.35, 0.45, 0.55) with various volume fractions of fine aggregate ($V_f$ = 0, 0.1, 0.2, 0.3 and 0.4) were cast and tested. To predict the equivalent migration coefficient ($M_e$) and migration coefficient of interfacial transition zone ($M_{itz}$), double-inclusion method and Mori-Tanaka theory were used to estimate. There are two stages to estimate and calculate the thickness of interfacial transition zone (h) and migration coefficient of interfacial transition zone ($M_{itz}$). The first stage, the data of experimental chloride ion migration coefficient ($M_s$) was used to calculate the equivalent migration coefficient of fine aggregate with interfacial transition zone ($M_e$) by Mori-Tanaka theory. The second stage, the thickness of interfacial transition zone (h) and migration coefficient of interfacial transition zone ($M_{itz}$) was calculated by Hori and Nemat-Nasser's double inclusion model. Between the theoretical and experimental data a comparison was conducted to investigate the behavior of interfacial transition zone in mortar and the effect of interfacial transition zone on the chloride migration coefficient, the results indicated that the numerical simulations is derived to the $M_{itz}/M_m$ ratio is 2.11~8.28. Additionally, thickness of interfacial transition zone is predicted from $10{\mu}m$, 60 to $80{\mu}m$, 70 to $100{\mu}m$ and 90 to $130{\mu}m$ for SM30, M35, M45 and M55, respectively.