• Transactions of Materials Processing
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• v.3 no.3
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• pp.335-346
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• 1994

The effect of sheet steel properties and lubrication on the optimal range of blank holding force (BHF) was investigated by means of the model die stamping of various sheet steels. The optimal range of blank holding force was expressed as the range between the lower BHF at flange wrinkling and the upper BHF at local necking. It showed that mechanical properties, thickness of sheet steel and lubrication condition were important factors affecting the optimal range of BHF in sheet steels. Especially, lubrication played an important role in the case of coasted sheet steels.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.05a
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• pp.415-418
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• 2008

We propose a criterion which predicts wrinkle initiation on workpiece in groove rolling process based on finite element analysis. Fundamental idea introduced in the criterion is to examine the difference between flat rolling which don't' cause wrinkling at all and groove rolling which usually accompanies it. The proposed criterion assumes that irregular distribution of shear strain on workpiece during groove rolling is attributable to the initiation of wrinkling. The proposed criterion has been applied to roughing train in the rod and bar mill of SEAH BESTEEL Inc. A new design for 2nd pass (square roll groove) was suggested, machined and applied. Results reveal that the proposed criterion in this study could point out the location of wrinkle initiation during groove rolling and could reduce onset of wrinkle on final products.

• Proceedings of the SCSK Conference
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• 2003.09a
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• pp.617-629
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• 2003

A recent development in cosmetics has been the pursuit of wrinkling in the skin. The cosmetics composed of anti-wrinkle agent stand out from the point of view of environmental contamination and pollution. Among them, Indole-3-acetic acid (IAA), studied with wrinkling pigmentation and swelling conditions in the area of the eye, showed clinically significant reduction in depth of lines during one month trial using skin treatment. But, IAA has shown some problems when used in cosmetic formulations, such as stability, permeability and toxicity. The results of the clinical examination were shown that its permeability and toxicity didn't matter. To increase the stability of IAA, antioxidants such as Licorice, ubiquinone, tocopherol, Baicalin, ferulic acid, BHT, ascorbic acid, sodium metabisulfite, and so on were employed in cosmetic formulations. Our main purpose is the study for the stability efficiency and effect of each other of cream formulations containing optimal dosage antioxidants (o/w type emulsion), This study evaluated wrinkle reduction effect of IAA, which is used in cosmetics.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2009.05a
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• pp.105-105
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• 2009

• Journal of Applied Biological Chemistry
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• v.58 no.2
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• pp.125-129
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• 2015

In this study, the antioxidant and anti-wrinkling effects of fraction from Vitex trifolia L. were investigated. Among the fractions, ethyl acetate fraction showed the highest antioxidant activities in 1-1-diphenyl-2-picryl-hydrazyl, 2,2'-azino-bis(3-ethylbenzothiazoine-6-sulfonic acid) radical scavenging and elastase inhibition with 76, 89, and 74%, respectively, at a concentration of $1,000{\mu}g/mL$. This fraction, at the concentration of $25{\mu}g/mL$, inhibited 70% fibroblast cell viability and 86% the matrix metalloprotease (MMP)-1. In addition, the results from Western blot assay showed that this fraction ($25{\mu}g/mL$) expressed the MMP-1 protein level by decreasing 50%. The findings suggest that the ethyl acetate fraction from V. trifolia has great potential as a cosmeceutical ingredient with antioxidant and anti-wrinkling effects.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.8
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• pp.36-43
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• 2003

In this study, a satellite payload module was optimized by considering local stabilities. As design constraints in the satellite structure, local instabilities such as wrinkling, dimpling, crippling for honeycomb structures and crippling failure mode for beams were considered in addition to frequency and stress constraints. The constraints for the local instabilities (uncommon in general structures) were taken for the optimization of a satellite structures under severe launching environments. The analysis was performed combining the finite element analysis and optimization program. From the optimization results, it was found that frequency, crippling and wrinkling were the most critical constraints to achieve the design goals. Also, the importance of each design variable was estimated. Finally, the optimum design of the payload module was achieved for various design constraints and design parameters.

• Microbiology and Biotechnology Letters
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• v.40 no.4
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• pp.364-370
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• 2012

In this study, the compounds of Prunus persica Flos were extracted with 70.0% acetone and were purified using a sephadex-LH-20 column chromatography. As a result, eight fractions were isolated. For whitening effects, the tyrosinase inhibitory activity was determined to be 92.2% in Fr.-8 isolated from P. persica Flos at 1.000 ppm. The melanoma cell-originated tyrosinase inhibitory effect of Fr.-8 from P. persica Flos was approximately 63.4% at 100 ppm. The inhibitory activity on melanin synthesis by Fr.-8 isolated from P. persica Flos was about 71.7% at 100 ppm concentration. For anti-wrinkling effects, the elastase inhibition activities by Fr.-5, 7 isolated from P. persica Flos were around 71.4 and 74.5% respectively at 1,000 ppm. The collagenase inhibition activity and collagen synthesis by Fr.-8 isolated from P. persica Flos was about 80.0% at 100 ppm. All these findings suggested that the fractions of P. persica Flos have great potential as cosmeceutical ingredients with whitening and anti-wrinkling effects.

• The Korea Journal of Herbology
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• v.31 no.4
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• pp.53-60
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• 2016

Objective : The purpose of this study was to investigate anti-aging and antioxidant effects of extracts of Nelumbo nucifera leaves (NN-L) using ethanol on skin .Methods : Each part of leaves(NN-L), flowers(NN-F) and stem(NN-S) was extracted with 70% ethanol. We performed radical scavenging assay(DPPH, ABTS+, Superoxide anion radical), elastase inhibition assay, collagenase inhibition assay. NN-L extracts were tested for cell viability(MTT assay), MMP-1 inhibition and MMP-1 protein expression on CCD-986sk cells (human fibroblast line).Results : Recently, many studies have reported that elastin is also involved in inhibiting or repairing wrinkle formation, although collagen is a major factor in the skin wrinkle formation. We measured its free radical scavenging activity, elastase inhibitory activity and expression of MMP-1 (matrix metalloprotease-1) in human fibroblast cells. Among the parts of Nelumbo nucifera, NN-L showed the highest antioxidant activities and in radical scavenging. DPPH, ABTS+ and Superoxide anion radical scavenging activity of NN-L at concentration of 1,000 μg/mL were 91.43%, 99.31% and 73.7% respectively. In vitro elastase and collagenase inhibition effects of NN-L at concentration of 1,000 μg/mL was 42.8% and 55.3% respectively. The ethanol extract of NN-L showed cell viability of 95.4% in 50 μg/mL concentration. In addition, The results from Western blot assay showed that NN-L decreased the expression of MMP-1 protein in a dose-dependent manner (by up to 35.0% at 50 μM).Conclusion : The findings suggest that the NN-L great potential as a cosmeceutical ingredient with antioxidant and anti-wrinkling effects.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.10a
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• pp.453-454
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• 2012

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.1313-1314
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• 2010