• Proceedings of the PSK Conference
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• 2003.10b
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• pp.236.1-236.1
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• 2003

Evaluation of solid surface properties is very important for formulation of solid dosage form, specially insoluble drugs. The contact angle of insoluble drugs was measured by the penetration rate into powder bed using Washburn equation and wicking method. From the measured contact angle data, the surface free energy value of pharmaceutical powders ${\gamma}$s was divided and analysized into the polar component, ${\gamma}$s$\^$p/ and the dispersion component, ${\gamma}$s$\^$d/. Furthermore, the data was interpreted for acid part, ${\gamma}$s$\^$+/ and base part, ${\gamma}$s$\^$$\square$/ of surface free energy. (omitted)

• Journal of the Korean Society for Precision Engineering
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• v.27 no.11
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• pp.46-56
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• 2010

The present research works investigated into the low velocity impact characteristics of DP 780 high strength steel sheet with 1.7 mm in thickness subjected to free boundary condition using three-dimensional finite element analysis. Finite element analysis was carried out via ABAQUS explicit code. Hyper-elastic model and the damping factor were introduced to improve an accuracy of the FE analysis. An appropriate FE model was obtained via the comparison of the results of the FE analyses and those of the impact tests. The influence of the impact energy and nose diameter of the impact head on the force-deflection curves, impact time, absorption characteristics of the impact energy, deformation behaviours, and stress-strain distributions was quantitatively examined using the results of FE analysis. The results of the FE analysis showed that the absorption rate of impact energy lies in the range of the 70.7-77.5 %. In addition, it was noted that the absorption rate of impact energy decreases when the impact energy increases and the nose diameter of the impact head decreases. The local deformation of the impacted region was rapidly increased when the impact energy was larger than 76.2 J and the nose diameter was 20 mm. A critical impact energy, which occur the instability of the DP780, was estimated using the relationship between the plastic strain and the impact energy. Finally, characteristics of the plastic energy dissipation and the strain energy density were discussed.

• Korean Chemical Engineering Research
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• v.57 no.1
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• pp.85-89
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• 2019

Cell-free protein synthesis utilizes the translational machinery in a cell extract. Unlike the conventional cell-based expression methods, not being affected by the conditions for cell growth, cell-free protein synthesis enables flexible manipulation of individual factors affecting the efficiency protein biosynthesis. However, the high cost and low stability of the energy sources to regenerate ATP have limited the use of cell-free synthesis for large-scale production of recombinant proteins. One of the approaches to address this problem is to use glucose as an alternative energy source to regenerate ATP through the glucose-metabolizing pathways in a cell extract. In this study, in an attempt to improve the efficiency of ATP regeneration by reinforcing oxidative phosphorylation process, we supplemented with cellular lipids to a glucose-fueled reaction mixture for cell-free protein synthesis. As a result of the lipid supplementation, the productivity of chloramphenicol acetyltransferase in a cell-free synthesis system using glucose increased more than 6 fold compared to when the lipid was not supplemented.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.781-781
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• 2003

• Korean Journal of Food Science and Technology
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• v.34 no.2
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• pp.170-173
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• 2002

Electron spin resonance (ESR) spectroscopy was used to detect free radicals in irradiated wheat flour and glutinous rice flour. They were irradiated with doses of 0, 0.1, 0.5, 1 and 2 kGy at room temperature using a Co-60 irradiator. Free radicals detected for irradiated wheat flour and glutinous rice flour were higher than those of unirradiated ones. Since concentration of free radicals linearly increased with applied doses $(0.1{\sim}2\;kGy)$, highly positive correlation coefficients $(R^2=0.9995{\sim}0.9998)$ were obtained between irradiation doses and free radical concentrations right after irradiation. Although concentration of free radicals slowly decreased with storage time, the characteristic ESR signals of free radical in irradiated samples were observed even after 4 weeks of storage at room temperature.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2006.11a
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• pp.325-326
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• 2006

• Proceedings of the Korean Nuclear Society Conference
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• 1999.05a
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• pp.436-436
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• 1999

• Proceedings of the Korean Nuclear Society Conference
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• 2003.10a
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• pp.246.1-246.1
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• 2003

• Journal of the Korean Solar Energy Society
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• v.38 no.6
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• pp.37-49
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• 2018

In this paper a new kind of unit-prefabricated building is shown. The unit-prefabricated buildings are made up living unit, energy unit, water unit. The design trend implemented the energy insulation, solar PV panels, energy storage system which are maintained for zero energy buildings. We made a prototype for zero energy flexible residential unit. The first step, we was evaluated the physical performance, insulation, airtightness. The second step, we was evaluated energy performance building to design heating and cooling system to combined PV system. As a results, the insulation performance wall was $0.18W/(m^2{\cdot}K)$. The results of air-tightness was 12.13 ACH@50 (1/h). The building energy demand ratings and solar energy generation has the possible to be ballanced.

• Structural Engineering and Mechanics
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• v.11 no.2
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• pp.185-197
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• 2001

This paper presents the effect of axial stretching on large amplitude free vibration of an extensible suspended cable supported at the same level. The model formulation developed in this study is based on the virtual work-energy functional of cables which involves strain energy due to axial stretching and work done by external forces. The difference in the Euler equations between equilibrium and motion states is considered. The resulting equations govern the horizontal and vertical motion of the cables, and are coupled and highly nonlinear. The solution for the nonlinear static equilibrium configuration is determined by the shooting method while the solution for the large amplitude free vibration is obtained by using the second-order central finite difference scheme with time integration. Numerical examples are given to demonstrate the vibration behaviour of extensible suspended cables.