• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.11a
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• pp.168-169
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• 2013

In this study, the chemical resistance of polyurea resin waterproofing and anti-corrosion materials that is applied to the social infrastructure was analyzed. The result in this study will be utilizing as a basic data for establishing the quality standards which are able to judge the chemically resistant characteristic of polyurea resin waterproofing and anti-corrosion materials.

• Proceedings of the KIEE Conference
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• 2002.11a
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• pp.31-33
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• 2002

변전기기뿐만아니라 모든 제품에 대해서 신뢰성의 증대가 요구되는 요즈음 당사에서는 에폭시절연물의 연구에 가일층 박차를 가하고있으며, 금번시험을 통하여 에폭시절연물의 성능검증방법이 향상되었음을 알게되었고 설계적인 측면에서 보완되어야할 사항이 무엇인가를 확인 할수 있었다.

• Journal of Applied Biological Chemistry
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• v.66
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• pp.503-511
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• 2023

The aim of this study was to investigate in vitro antioxidant activities of defatted Camellia japonica L. seeds (DCJS). The DCJS were extracted using ethanol and then fractionated with butanol (BuOH), ethyl acetate (EtOAc), chloroform, and hexane. To evaluate antioxidant activity of extract and fractions from DCJS, we investigated free radical scavenging activities such as 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS⁺), hydroxyl radical (^•OH), and superoxide anion (O₂^-) radicals. The five extract and fractions of DCJS dose-dependently increased DPPH, ABTS⁺ and O₂^- radical scavenging activities. The BuOH fraction of DCJS showed the highest free radical scavenging activities among other extract and fractions. The contents of total polyphenol and flavonoid in BuOH fraction of DCJS were 23.26 mg GAE/g and 32.39 mg QE/g, respectively. The polyphenol and flavonoids contents of BuOH fraction has highest than other extract and fractions. In addition, BuOH and EtOAc fraction of DCJS contained 102.37 and 165.05 ㎍/g of camelliaside B, respectively. Therefore, DCJS has higher antioxidant activity and may be useful as a natural antioxidant material.

• Food Science and Preservation
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• v.24 no.2
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• pp.196-205
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• 2017

This study was conducted to increase the functionality of Korean traditional beverage, Sikhye. The Sikhye were prepared by supplementation up to 20% of Seomaeyaksuk extract (SE) and saccharification for five hours (h). During the saccharification, turbidity of SE-added Sikhye (SES) was the highest at two hours of saccharification and then lowered gradually. L vlaue of SES did not show significant difference feduring saccharification, and both a and b value of Sikhye were increased as saccharification time passed and SE addition ratio was increased. The pH before saccharification was not significantly different by SE addition ratio but it was increased to 5.68-5.73 at 5 h saccharification. Soluble solid, total sugar and reducing sugar contents were enhanced as saccharification time and SE addition ratio were increased. The total phenolic compounds contents and DPPH radical scavenging activity showed a similar trend by saccharification time and SE addition. In sensory test, the evaluations of 5% SES and control were not significant different, but 20% SES group showed significant lower evaluation than other groups because strong color and mugwort flavor. From all of these results, physicochemical characteristics and antioxidant activity of SES was improved by SE addition but sensory characteristics was lower. Acceptable addition ratio of SE in Sikhye is determined to be within 15%.

• Korean Journal of Construction Engineering and Management
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• v.13 no.3
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• pp.43-55
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• 2012

A methodology for BIM Quality Assurance in the construction industry is becoming increasingly an important issue to determine the reliability of BIM. However, the quality assurance of BIM is currently limited to check 3D models, such as clash detection and space layout while verification methods for disciplinary BIM results from structural engineering, mechanical engineering, and estimation do not exist yet. Particularly, in the BIM-based estimation mathematical equations to take off quantities are not clearly exposed so that the results are not quite accepted at practices. With the concept of reliability engineering defined in the manufacturing industry to improve reliability of outcomes of BIM-based quantity take-off, impacting factors that affect reliability of BIM-based quantity take-off were derived. It was found that the factors also include the modeling method and the features of a BIM tool. Therefore, this research aims to propose modeling and verification methods to improve reliability of BIM-based quantity take-off through the pilot test that was performed with commercial BIM tools and IFC-based BIM data.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.10
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• pp.1601-1605
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• 2004

To develop the functional food, methanol extracts of dried plantain (Plantago asiatica L.) was fractionated in hexane, chloroform, ethyl acetate, butanol and aqueous fraction. DPPH radical scavenging effect, reducing power, nitrite scavenging effect and antimicrobial activities of these fractions were investigated. Ethyl acetate fraction among these fractions showed the highest effect of all experiments. Ethyl acetate fraction showed about 60% scavenging effect on the DPPH radicals at 400 $\mu$g/5 mL. Nitrite scavenging effect of ethyl acetate and butanol fraction was more than 70~80% at concentration above of 500 $\mu$g. Among various solvent fractions from methanol extracts of plantain, ethyl acetate fraction showed the highest inhibitory effect on the microorganism such as Staphylococcus aureus, Bacillus cereus and Vibrio parahaemolyticus at 5 mg/disc.

• Resources Recycling
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• v.24 no.1
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• pp.12-20
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• 2015

In this study, change of hydration property with contents and type of gypsum in ternary natural hydraulic lime containing blast furnace slag and gypsum was investigated. Anhydrite, hemihydrate and dihydrate were added 3 % and 10 %, respectively in natural hydraulic lime adding blast furnace slag 20 %. Hydration and physical behavior due to solubility and reactivity of different types of gypsum were analyzed in early hydration. As a result of analysis of hydration properties, in all samples, hydrates such as ettringite and C-S-H were produced in early hydration, and amount of hydrates with increase of hydration time was increased. In the case of compressive strength, when contents of gypsum are 3 %, it was higher compressive strength than other specimens. At hydration 28 days, for addition of anhydrite and hemihydrate, compressive strength was more than adding dihydrate.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.1
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• pp.845-852
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• 2015

This study examined the flexural strength of CFS reinforced concrete beams with various load histories. The RC beams to be reinforced by CFS have undergone various loading histories but neglecting the loading history results in a few problems in structural safety and cost. Structural behavior of CFS-strengthened RC beams were analyzed considering the strain status of RC beams under loads at the time of CFS strengthening. Nonlinear section analysis showed that the flexural strength of CFS-strengthened RC beams depends on the load history of the RC beams. From the result of this analysis, the flexural strength of a CFS-strengthened concrete beam is affected considerably by the load history and should be considered in CFS reinforcement.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.231-234
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• 2010

Analysis of conjugated heat transfer has been conducted for the diffuser exposed to hot combustion gas to design the mechanical durability in high temperature. All the heat transfer means, conduction, convection and radiation have been considered to calculate the total heat flux from hot gas to diffuser surface. The calculation has been implemented by two kinds of methods. One thing is one dimensional method based on empirical equations. The other is CFD(Computational Fluid Dynamics) axisymmetric calculation containing ${\kappa}-{\omega}$ SST(Shear Stress Transport) turbulent model and DO(Discrete Ordinate) radiation model. The derived results of two methods have compared and showed similar values. From this result, the amount of cooling water and the dimension of water cooling channel were decided.

• Journal of Animal Science and Technology
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• v.55 no.5
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• pp.475-481
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• 2013

The objective of this study was to investigate the effect of red ginseng extracted with water extract (WE) and 50% ethanol extract (EE) from white ginseng on cooked meat patties during storage. Different concentrations of extracts were examined (0.25%, 0.5%, and 1.%, respectively, dry base w/w). A significantly higher water holding capacity (WHC) was observed in samples supplemented with ${\geq}$ 0.5% WE (p < 0.01); however, EE had no significant effect on the WHC of meat patties. Samples supplemented with ${\geq}$ 0.5% WE or EE showed a significantly higher redness ($a^*$-value) compared to the control (p < 0.01). The total plate counts (TPC) and 2-thiobarbituric acid-reactive substances (TBARS) of all treated samples were lower than those of the control. However, there were no significant differences in volatile basic nitrogen (VBN) values and sensory evaluation scores between the samples. These results suggest that red ginseng extract improves color and inhibits lipid oxidation and bacterial population at doses > 0.25%, prolonging the shelf-life of meat products and acting as a natural colorant.