• Korean Journal of Metals and Materials
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• v.49 no.3
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• pp.231-236
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• 2011

Nanopowder of $Fe_2O_3$, Al, Cr and Si was fabricated by high energy ball milling. A dense nanostuctured $A_2O_3$ and $6.06Fe_{0.33}Cr_{0.16}Al_{0.23}Si_{0.29}$ composite was simultaneously synthesized and consolidated using high frequency induction heated sintering method within 1 minute from mechanically activated powders of $Fe_2O_3$, Al, Cr and Si. The grain sizes of $Al_2O_3$ and $Fe_{0.33}Cr_{0.16}Al_{0.23}Si_{0.29}$ in composite are 80 and 18 nm, respectively.

• Journal of the Korean Institute of Rural Architecture
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• v.12 no.2
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• pp.125-133
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• 2010

The advanced rural village development project started in 2005, and this project of purpose is improvement of housing environment and promotion of region activation. Researcher investigated about the advanced rural village development project of nine complex through field survey. The aim of this study is to be offered data of idyllic housing policy by examination actual conditions of study subject. Based on this study, mainly three results can be drawn as follows ; first, this project makes a great contributed to flow in population from urban to activate rural areas. Second, the project success depends on improvement an institution and planed, timely approach. Third, central government must plan network system with rural development project in political, and must support local government into political frame. The local government must consider a regional housing plan overall and must make an effort itself for the project success.

• Proceedings of the Korean Nuclear Society Conference
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• 2005.10a
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• pp.400-401
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• 2005

• Journal of Powder Materials
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• v.14 no.4
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• pp.245-250
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• 2007

Dense nanostructured $2MoSi_{2}-SiC$ composites were synthesized by the pulsed current activated combustion synthesis (PCACS) method within 3 minutes in one step from mechanically activated powders of $Mo_{2}C$ and 5Si. Simultaneous combustion synthesis and densification were accomplished under the combined effects of a pulsed current and mechanical pressure. Highly dense $2MoSi_{2}-SiC$ with relative density of up to 96% was produced under simultaneous application of a 60 MPa pressure and the pulsed current. The average grain size of $MoSi_{2}$ and SiC were about 120 nm and 90 nm, respectively. The hardness and fracture toughness values obtained were 1350 $kg/mm^{2}$ and 4 $MPa{\cdot}m^{1/2}$, respectively.

• Korean Journal of Metals and Materials
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• v.48 no.7
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• pp.639-643
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• 2010

Nanopowder of FeAl was synthesized by high energy ball milling. Using the pulsed current activated sintering method, a dense nanostuctured FeAl was consolidated within 2 minutes from mechanically synthesized powders of FeAl and horizontally milled powders of Fe+Al. The grain size and hardness of FeAl sintered from horizontally milled Fe+Al powders and high energy ball milled FeAl powder were 150 nm, 50 nm and $466\;kg/mm^2$, $574\;kg/mm^2$, respectively.

• Korean Journal of Metals and Materials
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• v.48 no.11
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• pp.1009-1013
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• 2010

Extremely dense WC with a relative density of up to 99% was obtained within five minutes under a pressure of 80 MPa using the High-Frequency Induction Heated Sintering method. The average grain size of the WC was about 71 nm. The advantage of this process is not only rapid densification to obtain a neartheoretical density but also the prohibition of grain growth in nano-structured materials. The hardness and fracture toughness of the dense WC produced by HFIHS were $2660kg{\cdot}mm^{-2}$ and $7.2MPa{\cdot}m^{1/2}$, respectively.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.173-173
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• 2010

Recently, a patterned sapphire substrate (PSS) has been intensively used as one of the effective ways to reduce the dislocation density for the III-nitride epitaxial layers aiming for the application of high-performance, especially high-brightness, light-emitting diodes (LEDs). In this paper, we analyze the growth kinetics of the atoms and crystalline quality for the undopped-GaN depending on the facets of the pattern fabricated on a sapphire substrate. The effects of the PSS on the device characteristics of InGaN/GaN LEDs were also investigated. Several GaN samples were grown on the PSS under the different growth conditions. And the undoped-GaN layer was grown on a planar sapphire substrate as a reference. For the (002) plane of the undoped-GaN layer, as an example, the line-width broadening of the x-ray diffraction (XRD) spectrum on a planar sapphire substrate is 216.0 arcsec which is significantly narrower than that of 277.2 arcsec for the PSS. However, the line-width broadening for the (102) plane on the planar sapphire substrate (363.6 arcsec) is larger than that for the PSS (309.6 arcsec). Even though the growth parameters such as growth temperature, growth time, and pressure were systematically changed, this kind of trend in the line-width broadening of XRD spectrum was similar. The emission wavelength of the undoped-GaN layer on the PSS was red-shifted by 5.7 nm from that of the conventional LEDs (364.1 nm) under the same growth conditions. In addition, the intensity for the GaN layer on the PSS was three times larger than that of the planar case. The spatial variation in the emission wavelength of the undoped-GaN layer on the PSS was statistically ${\pm}0.5\;nm$ obtained from the photoluminescence mapping results throughout the whole wafer. These results will be discussed in terms of the mixed dislocation depending on the facets and the period of the patterns.

• Plant Biotechnology Reports
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• v.4 no.2
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• pp.173-178
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• 2010

An efficient protocol for shoot regeneration was developed for sesame (Sesamum indicum L.) internodes using the transverse thin cell layer (tTCL) culture method. The frequency of shoot regeneration and the number of adventitious buds produced from regenerated shoots depend significantly on explant age, thickness of the tTCL sections, and the phytohormones supplemented to the culture medium. A combination of 6-benzyladenine (2.0 $mg\;l^{-1}$) and a-naphthaleneacetic acid (0.5 $mg\;l^{-1}$) was found to be the best phytohormone combination for shoot bud induction, with the maximum number of shoots obtained when the tTCL sections were 0.5-1.0 mm thick and derived from 4- to 6-week-old seedlings of sesame. Well-developed shoots were rooted on MS medium without phytohormones, and 80% of the regenerated plantlets were successfully established in soil.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.3
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• pp.273-278
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• 2016

This study makes a relative comparison of the results of tensile test and quasi-static analysis using AGL(Adjuster Guide Loop) model that plays a role in adjusting the height of shoulder belt, of the components of the vehicle seatbelt system and attempts to propose a method of reducing the error rate of the quasi-static analysis technique effectively. This study selects two major factors affecting the result of an analysis, draws the result of analysis through the method of experimental design, one of the statistical techniques and understands the contribution rate of the major factors affecting the result of the analysis through ANOVA(Analysis of Variance).

• BMB Reports
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• v.28 no.1
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• pp.79-82
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• 1995

Exposure of spleen lymphocytes to 2-chloroethylethyl sulfide (CEES) leads to a reduction of the intracellular ATP level, followed by a decrease in cell viability. Addition of nicotinamide, an inhibitor of poly(ADP-ribose) polymerase (PADPRP), restores both ATP level and viability, indicating that an activation of PADPRP is responsible for the cytotoxicity of CEES. The involvement of a $Ca^{2+}$-mediated process in cytotoxicity is suggested. Verapamil, EGTA, trifluoperazine, and butacaine exhibit a partial protection (20 to 58%) against the cytotoxicity of CEES. Investigation of the causative role of proteolytic degradation in cell death indicate that pepstatin and leupeptin exert a substantial protective effect (60 to 70%), suggesting the involvement of lysosomal destabilization in CEES-induced cytotoxicity. Also, lysosomotropic agents markedly decrease the cytotoxicity. Lysosomal labilization may be a mechanism for the cytotoxicity of CEES.