• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.6
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• pp.11-20
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• 2014

This paper aims at comparing and analyzing shear buckling characteristics between sinusoidal corrugation shape and trapezoidal one. For this, I adopted the equal-length trapezoidal corrugation and sinusoidal one for the analytical models, and analyzed their shear buckling characteristics through linear buckling analysis and on its theory. Generally, the shear buckling shapes of corrugated steel plates are classified into local buckling, global buckling, and interactive buckling from the two buckling modes. Sinusoidal corrugation shape, unlike trapezoidal corrugation, does not have flat sides, which causes another tendency in shear buckling mode. Especially, the changes and different aspects of shear buckling on the boundary between local buckling and global buckling appear in different corrugation shapes. According to the analysis results, interactive buckling mode appeared on the boundary of local buckling and global bucking in trapezoidal corrugation. However, in the case of corrugated steel plates with sinusoidal configuration, interactive buckling mode appeared in the part where global bucking takes place. Besides, trapezoidal shapes are of advantages on shear buckling resistance in the local buckling section, and so are sinusoidal shapes in the global buckling section.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.24 no.2
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• pp.16-39
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• 1998

앞으로의 화장품 연구에 있어서 과거 화장품 기술이 어떻게 발전되어 왔으며, EH 현재 중점적으로 연구되고 있는 분야에 관하여 살펴 보았다. 이러한 분야 중 주름방지, 미백, 자외선차단, 방향효과, 제형개발, 안전성 유효성 연구에 관하여 현재의 연구되고 있는 분야를 간략히 살펴보았다. 그리고 앞으로 화장품은 어떠한 방향으로 이루어지며, 또 이러한 화장품을 개발하기 위하여 방향에서 연구가 이루어져야 하는지에 관하여 개략적으로 살펴보았다.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.37 no.4
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• pp.289-295
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• 2011

Recently, the number of customers who want natural cosmetics without petroleum originated cosmetic ingredients is increasing over the world, however, there are few natural cosmetics that claim functionality in the products. Because there are few functional cosmetic ingredients from nature and though so, it is very difficult to stabilize the final products manufactured by using those functional cosmetic ingredients in the long period. This study is on stabilization of oleanolic acid, insoluble anti-wrinkle cosmetic ingredients from nature, with hydrogenated lecithin in the solubilization product, aiming for developing a formulation of solubilization products which can be certified as organic cosmetics. In case of other synthetic solubilizers, they showed unstability at $45^{\circ}C$ within 2 ~ 3 days, however, for natural origin hydrogenated lecithin a stable product was made without particle size change during 4 weeks. The stability of oleanolic acid in the solubilization product was measured for 24 weeks at $25^{\circ}C$ and $40^{\circ}C$, both samples showed over 90 wt% value of the initial one, which can prove that oleanolic acid was stabilized in the product without any degradation. Also through clinical tests, the effect of moisturizing, anti-wrinkle, safety were confirmed.

• Journal of Life Science
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• v.29 no.4
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• pp.442-446
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• 2019

We recently reported the characteristics of Chrysanthemum boreale MAKINO essential oil (CBMEO) at different harvesting stages and its in vitro antioxidant, whitening, skin regeneration, and antiwrinkle properties. In the present study, we investigated the effectiveness of cosmetic creams containing 0.1% of CBMEO in terms of wrinkle reduction and safety. The participants were 22 women aged 42 to 60 y with natural wrinkles. All the participants applied the CBMEO-containing cream to the eye area for 8 weeks. Visual observations of the skin by a dermatologist were used to assess the safety of the product, and improvements in skin wrinkles (roughness) were analyzed using a skin visiometer. Neither the CBMEO-containing cream nor the placebo caused abnormal reactions, such as erythema or allergies, during the test period. The CBMEO-containing cream-exposed test regions showed a greater reduction in the roughness index as compared with those of the placebo-exposed control regions. The R1, R2, and R3 indices showed a statistically significant decrease in the test regions as compared with the placebo control regions after using the cream for 2 weeks (p<0.05). Therefore, this study demonstrated that CBMEO-containing cosmetics are safe for human use and that they have skin wrinkle improvement properties. In the future, CBMEO may be a promising product for use in the development of functional anti-wrinkle cosmetics.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.49 no.1
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• pp.47-58
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• 2023

Recently, along with the remarkable increase in interest in microbiome cosmetics, the application of microbiome extracts in the complex efficacy as anti-aging, brightening etc. has become very important. In this study, Bifidobacterium bifidum (B. bifidum), which has excellent anti-wrinkle efficacy among the microbiome, was selected through an in vitro test using cells and 3D human skin equivalents. And the anti-wrinkle efficacy of cosmetics containing B. bifidum was evaluated by clinical test. Thereafter, the cytotoxicity, anti-oxidation, anti-inflammatory and anti-wrinkle efficacy of the of the bifida fermented filtrate were tested. An emulsion containing bifida fermented filtrate at a concentration of 5% (v/v) with no cytotoxicity and excellent efficacy was prepared with the placebo emulsion. The clinical test was conducted on a total of 21 women at 2 weeks comparing the bifida emulsion and placebo emulsion. Wrinkles around the eyes were instrumentally evaluated using Antera 3D. The wrinkle reduction rate of the Bifida emulsion group compared with the placebo emulsion group differed by 5.6%. Overall, the selection of microbiome using 3D human skin equivalents and the efficacy study of cosmetics with the microbiome extracts would be actively studied to the development of microbiome cosmetics and skin microbiome mechanisms.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.49 no.3
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• pp.203-212
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• 2023

This study was conducted to investigate the possibility of peanut shell, a by-product of peanut, as a functional cosmetic ingredient. Peanut shell extract showed high antioxidant activity with IC₅₀ values of 75.00, 46.33, and 472.83 ㎍/mL for DPPH and ABTS radical scavenging and SOD-like activity, respectively. Furthermore, peanut shell extract was efficiently decreased the MMP-1 and MMP-3 protein level in the UVB treated-HaCaT cell and maintained procollagen protein level similar to normal control. Similar to anti-wrinkle related protein expression assay, the IC₅₀ value of elastase and collagnease inhibition in peanut shell extract was lower as 0.30 and 0.09 mg/mL, respectively, than that of the positive control. Additionally, eriodictyol and luteolin, which are isolated from peanut shell extract, showed 53.8 and 98.0% elastase inhibition rate, respectively, and 60.1 and 72.5% collagenase inhibition rate, respectively, at a concentration of 0.1 mg/mL. Thus, luteolin was assumed to be the effective ingredient for wrinkle inhibition in peanut shell extract. As a result of stability evaluation of lotion and cream formulations containing peanut shell extract, it was confirmed to be a stable formulation with no significant changes. Therefore, it is considered that peanut shell extract can be applied as a cosmetic ingredient for wrinkle inhibition.

• Korean Chemical Engineering Research
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• v.52 no.6
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• pp.701-705
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• 2014

Water extracts of root, leaf, branch and fruit of Cudrania tricuspidata were tested to use as natural antiwrinkle and whitening cosmetic ingredient. Root extract indicated 86.5 mg/g polyphenol concentration and 55.5 mg/g flavonoid concentration. From MTT test, root, branch and fruit extract did not show cell toxicity up to $1,000{\mu}g/mL$, however, leaf extract displayed significant cell toxicity in concentrations higher than $200{\mu}g/mL$. Cudrania tricuspidata root extracts displayed excellent 81% tyrosinase inhibition (whitening effect), 58% elastase inhibition (antiwrinkle effect) at $500{\mu}g/mL$ and showed minor UVB absorbance. When solution and lotion formulation were made including Cudrania tricuspidata root extract, they are stable at $25^{\circ}C$ for 21 days, but showed significant deviation in viscosity and particle size at $47^{\circ}C$. From the study, Cudrania tricuspidata root extract demonstrated good potential for natural whitening and antiwrinkle cosmetic agent.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.4 s.48
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• pp.457-462
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• 2004

Anti-wrinkle effect of N-Acetyl-D-glucosamine (NAG) was evaluated by collagen synthesis and proliferation of normal human fibroblast. NAG was obtained by purifying deacetylated chitin which can be derived from chitin-rich crab shell. We studied in in-vitro cultures of human normal fibroblast, whether synthesis of collagens and fibroblast growth activation in these cells can be enhanced in the presence of NAG. It 야d not show any adverse effects in human shin irritation patch test. In in-vivo mouse test, it showed anti-wrinkle effect in hairless mouse (6W/F). From the HPLC analysis, the stability of NAG in the cosmetics product could be maintained for a long time. These results demonstrated that NAS can be useful anti-wrinkle cosmetic ingredient.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.3
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• pp.10-19
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• 2014

Corrugated steel plates are made by fabricating thin steel plates to have trapezoidal or sinusoidal corrugation, and the corrugated plates are able to maintain high out-of-plane rigidity even when they are used instead of thick flat plates. Also, corrugated steel plates have almost no axial rigidity due to the accordion effect. Thus, if they are applied to the webs of plate girders, designing can be easily conducted so that the webs bear only shear stresses. However, unlike flat plates, the shear buckling of corrugated steel plates has very complex characteristics where buckling occurs due to the interaction of local and global buckling, besides local buckling and global buckling. For the investigation of the cause and characteristics of this interactive buckling, studies on sinusoidal corrugated steel plates are fewer than studies on trapezoidal corrugated steel plates. Therefore, in this study, the shear buckling characteristics of sinusoidal corrugated steel plates and the occurrence pattern of interactive buckling were investigated. For the calculation of shear buckling strength, a finite element program was used, and the analysis results were compared with the exact solution. In addition, the characteristics of buckling stress change and the change of buckling mode shape depending on corrugation thickness and shape parameter were analyzed, and by comparing these results with the results of a theoretical equation, the timing of buckling mode change was analyzed.

• Korean Chemical Engineering Research
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• v.53 no.3
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• pp.289-294
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• 2015

In this research, water and ethanol extract of Momordica charantia shells, fruits and seeds were tested to see possibility as natural functional cosmetic agent. Water and ethanol extract showed 69.45 mg/g and 70.87 mg/g polyphenol concentration, respectively. Momordica charantia water and ethanol extracts did not indicate cell toxicity up to $1,000{\mu}g/ml$ concentration in MTT assay. Tyrosinase inhibition effects of water and ethanol extract were lower than arbutin, however, ethanol extract showed better DOPA oxidation inhibition effect than arbutin. Elastase inhibition effects of ethanol extract displayed similar efficacy with adenosine at higher concentrations. Solution formulations (5% extract) were stable for 28 days in both extracts, however, lotion formulation (1% extract) showed considerable variation in viscosity whereas ethanol extraction indicated relative stability. In conclusion, water and ethanol extract of Momordica charantia shells, fruits and seeds indicated strong possibility for whitening and antiwrinkle functional cosmetic ingredient.