• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.11a
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• pp.17-18
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• 2014

Recently, climate change have increased consumption of building heating and cooling energy. Therefore, various actions to reduce greenhouse gas and energy consumption have been prepared by world developed countries. The energy consumption by buildings approximately reaches 25% of total korea energy consumption. The greatest part in the buildings of the energy consumption is building facade. Especially the outer covering of the building has been made of concrete more than 70%. But a few research projects on concrete comprising more than 70% of outsider of buildings has been tried. This research is structural insulation concrete what improved insulation performance using Micro Form Admixture and Calcined Diatomite Powder and Lightweight Aggregate.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.12 no.5
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• pp.59-66
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• 2003

This study suggests the new ultraprecision finishing techniques for micro die and mold parts using magnetic field-assisted polishing. Conventional magnetic abrasives have several disadvantages, which are missing of abrasive particle and inequal mixture between magnetic particle and abrasive particle. Therefore, bonded magnetic abrasive particles are fabricated by several method. For example, plasma melting and direct bonding. Carbonyl iron powder is used as magnetic particle there silicon carbide and alumina are abrasive particles. Developed magnetic abrasives are analyzed using SEM. Feasibility of magnetic abrasive and polishing performance of this magnetic abrasive particles also have been investigated. After polishing, surface roughness of workpiece is reduced from 85.4 ㎚ Ra to 9 ㎚ RA.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2423-2428
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• 2008

A turbo classifier having a rotating rotor of two stage classification region has been developed to have a cut size of 1 micro meter. Particle number concentrations were counted using Aerosol Particle Sizer (APS, TSI co., USA) at inlet and outlet of the classifier. Partial classification efficiency was obtained at various rotation speeds, total flow rates, and feed rates of powders, and classification characteristic depending on design parameters was discussed. Classification performance was enhanced as rotation speed of rotor increased and total flow rate decreased.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.05a
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• pp.227-228
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• 2013

Recently, it is certain that the increase of heating and cooling energy consumption by radical change in climate condition has caused serious problems related to environmental and energy concerns associated with increase of fossil fuel usage and carbon dioxide production as well as global warming. So, various actions to reduce greenhouse gas exhaustion and energy consumption have been prepared by world developed countries. The energy consumption by buildings approximately reaches 25% of total korea energy consumption. The greatest part in the buildings of the energy consumption is building facade. but a few research projects on concrete comprising more than 70% of outsider of buildings has been tried. This research structural insulation concrete what improved insulation performance using insulation performance improve material.

• Proceedings of the KAIS Fall Conference
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• 2004.06a
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• pp.267-269
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• 2004

본 연구에서는 일반적인 미세구조물 제작공정인 lithography 공정을 이용하지 않고 SLS(Selective Laser sintering)형 RP(Rapid Prototyping system)을 이용하여 패턴의 깊이가 400$\mu$m인 미세구조물을 제작하였다. 제작 공정변수 중 재료의 상태가 new powder 이고 배치각이 $0^{\circ}$ 일 때 패턴의 깊이, 선폭과 표면조도가 가장 잘 구현되었다.

• Journal of Power System Engineering
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• v.15 no.5
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• pp.72-76
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• 2011

In this work, the parameter optimization for thermal-sprayed Al/SiC composites have been designed by $L_9(3^4)$ orthogonal array and analysis of variance(ANOVA). Al/SiC composites were fabricated by flame spray process on steel substrate. The hardness of composites were measured using micro-vickers hardness tester, and these results were analyzed by ANOVA. The ANOVA results showed that the oxygen gas flow, powder feed rate and spray distance affect on the hardness of the Al/SiC composites. From the ANOVA results, the optimal combination of the flame spray parameters could be extracted. It was considered that experimental design using orthogonal array and ANOVA was efficient to determine optimal parameter of thermal-sprayed Al/SiC composites.

• Korean Journal of Metals and Materials
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• v.48 no.8
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• pp.775-779
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• 2010

Functionally graded materials (FGM) of PSZ/NiCrAlY on Inconel substrate were fabricated by detonation gun spraying method. A thick ceramic layer generally has a high thermal barrier effect however, because failure often occurs, the use of an FGM layer gives an advantage in thermal property. During the thermal shock test, micro fracture processes were detected by the AE method. Also, the thermal shock test was performed for NFGM, FGM and the changed FGM in the layered composition profile. It was found through AE testing and the observation of fracture surface that FGM was superior to NFGM in thermal shock properties. The linear or metal-rich type FGM in composition profile had the best resisting property among the FGM. It was found that the controlled composition profile of the graded layers had better thermal properties.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.139-140
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• 2023

This study aims to determine the microstructural characteristics of waste glass beads, a lightweight aggregate manufactured from waste glass powder, when incorporated into mortar in order to examine its usability depending on the particle shape.

• Journal of Life Science
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• v.28 no.7
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• pp.827-834
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• 2018

In this study, the biological activities of aqueous, ethanol, and methanol extracts of larvae of the edible insect Protaetia brevitarsis seulensis, fermented using several kinds of microorganisms, were tested in in vitro experimental models. Six effective microorganisms were used for fermentation, namely Lactobacillus plantarum JBMI F3, Lactobacillus plantarum JBMI F5, Lactobacillus gasseri Ba9, Aspergillus kawachii KCCM 32819, Saccharomyces cerevisiae KACC 93023, and Bacillus subtilis KACC 91157. Biological activities (${\alpha},{\alpha}^{\prime}-diphenyl-{\beta}-picrylhydrazyl$ [DPPH] free radical scavenging activity, reducing power, and fibrinolytic activity), and biochemical properties (phenolic compounds and flavonoids) were examined in aqueous, ethanol, and methanol extracts from P. brevitarsis seulensis powder and fermented P. brevitarsis seulensis powder. The total phenolic compounds and flavonoid contents were highest in the aqueous extract of B. subtilis-fermented P. brevitarsis seulensis powder. DPPH radical scavenging activity and reducing power were stronger in the fermented group than the nonfermented group. Fibrinolytic activity were highest in the extract from B. subtilis-fermented P. brevitarsis seulensis powder. The ${\alpha}-amylase$ activity in starch was higher in the fermented group than the nonfermented group, but there was no significant difference. These results provide basic data to understand the biological activities of bioactive materials derived from fermented P. brevitarsis seulensis larvae for the development of functional foods.

• Journal of the Mineralogical Society of Korea
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• v.20 no.4
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• pp.339-349
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• 2007

For various types of the Pungchon limestone, diverse mineral characters of the limestone including their size and morphology are investigated by using of ELS and SEM to examine the possibility of application as fillers to paper industry. Also, the measurement of zeta potential and the evaluation of coagulation properties in calcite suspension was made for fine powders of the limestone to examine the applicability and efficiency in wet-papermaking process. Fine powder of the Pungchon lime-stone, largely controlled by original mineral characters of ore in mineralogical aspects, exhibits some-what different trend in particle morphology according to ore types, and thereby, the size distribution, zeta potential and coagulation properties also become different. The examined whiteness, brightness, opacity and sheet strength in hand sheet also show remarkable differences according to ore types. These are seemed to be basically due to the results of combined effects of whiteness, site distribution, refractive index, and morphology of the limestone powder on the properties of hand sheet. Considering the investigated results, all types of the Pungchon limestone appear to be sufficiently applicable to paper industry. Especially, the mega-crystalline calcite type is evaluated to be overall suitable for the purpose of paper industry due to the higher values in whiteness and brightness. In addition the fine powder of micro-crystalline calcite type is assessed particularly to have a good quality in sheet strength by virtue of irregular particle shape.