• Journal of the Korean Society of Clothing and Textiles
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• v.23 no.6
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• pp.853-863
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• 1999

the change of physical properties (thickness, weight, air permeability) and mechanical properties(abrasion resistance breaking load and displacement) of samples were determined after heat exposure by a RPP tester. The effect of exposure time and heat flux intensity on the changes and the relationship between physical properties and mechanical properties were investigated. FR treated cotton Kevlar/PBI and Nomex with different structureal characteristics were chosen for specimens. The changes of physical properties and mechanical properties were calculated based on their initial values before heat exposure. The longer exposure time and the high heat flux intensity the more changes of those properties. Heat flux intensity was more effective on the changes, The showed to be affected by an interplay of shrinkage and pyrolysis products loss. The changes of thickness and abrasion resistance showed to be higher for plain weave fabric and those of air permeabiliyt and breaking load and displacement for twill weave fabric. While FR treated cotton which have high RPP value experienced serious and detrimental changes after heat exposure Kevlar/PBI which has low RPP value showed no high changes. In conclusion it could be confirmed that when total performance of a protective clothing is estimated retention capability of physical and mechanical properties after heat exposure as well as RPP value must be considered.

• Journal of the Korean Society of Clothing and Textiles
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• v.46 no.1
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• pp.132-146
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• 2022

To explore the potential use of Ecklonia cava as a natural dye for textiles, silk fabric was dyed with Ecklonia cava extracted by hot water under varied conditions, including temperature, duration, dye concentration, mordanting, and pH adjustment. The fabric was also evaluated for fastness, sun-protective property, and deodorization. Ecklonia cava extract was estimated by FT-IR to have polyphenol as a main functional colorant in plants, while the existence of phlorotannins through the UV-spectrum method was also confirmed. The fabric was optimized for maximum dye uptake at a temperature of 80℃ for a duration of 50 minutes along all dye concentrations. The dyed fabric showed a hue of Yellow Red under all dyeing conditions while additional color tones, such as grayish and dark, were generated through mordanting and pH adjustment. Both good sun-protective properties and a positive deodorization rate were also recorded, with more than 20% (owf) Ecklonia cava extract on silk fabric. These results imply that Ecklonia cava has great potential to be used as an eco-friendly natural dye and in fashion goods with skin-health functions made of silk.

• Microbiology and Biotechnology Letters
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• v.50 no.3
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• pp.375-386
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• 2022

In the present study, four distinctly colored bacterial isolates that show intense pigmentation upon brief ultraviolet (UV) light exposure are chosen. The strains are identified as Micrococcus luteus (Milky yellow), Cryseobacterium pallidum (Yellow), Cryseobacterium spp. (Golden yellow), and Kocuria turfanensis (Pink) based on their morphological and 16S rDNA analysis. Moderate salinity (1.25%), 25-37℃ temperature, and pH of 7.2 are found to be the most favorable conditions of growth and pigment production for all the selected isolates. The pigments are extracted using methanol: chloroform (1:1) and the purity of the pigments are confirmed by high-performance liquid chromatography (HPLC) and thin-layer chromatography (TLC). Further, Fourier transform infrared (FTIR) and UV-Visible spectroscopy indicate their resemblance with carotenoids and flexirubin family. The antioxidant activities of the pigments are estimated, and, all the pigments have shown significant antioxidant efficacy in 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picryl-hydrazyl (DPPH), and ferric reducing antioxidant power (FRAP) assays. The UV protective property of the pigments is determined by cling-film assay, wherein, at least 25% of UV sensitive Escherichia coli survive with bio-pigments even after 90 seconds of UV exposure compared to control. The pigments also hold a good sun protective factor (SPF) value (1.5-4.9) which is calculated with the Mansur equation. Based on these results, it can be predicted that these bacterial pigments can be further developed into a promising antioxidant and UV-protectant for several biomedical applications.

• Journal of Ginseng Research
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• v.36 no.1
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• pp.68-77
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• 2012

In this study, we investigated the protective effects of processed Panax ginseng, sun ginseng (SG) against the UVB-irradiation on epidermal keratinocytes and dermal fibroblasts. Pretreatment of SG in HaCaT keratinocytes and human dermal fibroblasts reduced UVB-induced cell damage as seen by reduced lactate dehydrogenase release. We also found that SG restored the UVB-induced decrease in anti-apoptotic gene expression (bcl-2 and bcl-xL) in these cells, indicating that SG has an anti-apoptotic effect and thus can protect cells from cell death caused by strong UVB radiation. In addition, SG inhibited the excessive expression of c-jun and c-fos gene by the UVB in HeCaT cells and human dermal fibroblasts. We also demonstrated that SG may exert an anti-inflammatory activity by reducing the nitric oxide production and inducible nitric oxide synthase mRNA synthesis in HaCaT keratinocytes and human dermal fibroblasts. This was further supported by its inhibitory effects on the elevated cyclooxygenase-2 and tumor necrosis factor-${\alpha}$ transcription which was induced by UVB-irradiation in HaCaT cells. In addition, SG may have anti-aging property in terms of induction of procollagen gene expression and inhibition of the matrix metalloprotease-1 gene expression caused by UVB-exposure. These findings suggest that SG can be a potential agent that may protect against the dermal cell damage caused by UVB.

• Korean Journal of Pharmacognosy
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• v.41 no.4
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• pp.264-269
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• 2010

In this study, the cellular protective effect, antioxidative property and component analysis of Euphorbia humifusa extracts were investigated. The ethyl acetate fraction ($3.68\;{\mu}g/mL$) and aglycone fraction ($3.15\;{\mu}g/mL$) of Euphorbia humifusa extract showed prominent free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activity ($FSC_{50}$). Reactive oxygen species (ROS) scavenging activity ($OSC_{50}$) of Euphorbia humifusa extract on ROS generated in $Fe^{3+}$-EDTA/$H_2O_2$ system was investigated using the luminol-dependent chemiluminescence assay. The ethyl acetate fraction ($0.43\;{\mu}g/mL$) and aglycone fraction ($0.35\;{\mu}g/mL$) of extract showed higher ROS scavenging activity than L-ascorbic acid ($1.50\;{\mu}g/mL$). The cellular protective effects of fractions of Euphorbia humifusa extract on the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. The ethyl acetate fraction and aglycone fraction of extract protected cellular membranes against ROS in a concentration dependent manner ($5{\sim}25\;{\mu}g/mL$), and was more effective than (+)-${\alpha}$-tocopherol, lipid peroxidation chain blocker. Aglycone fraction from Euphorbia humifusa extract showed 2 bands in TLC and 2 peaks in HPLC. In HPLC chromatogram of aglycone fraction, peak 1 and peak 2 were identified as quercetin and kaempferol, respectively. And these components are very effective as antioxidant. Thus, these results indicate that fractions of Euphorbia humifusa extracts can function as antioxidant in biological systems, particularly skin exposed to UV radiation by scavenging $^1O_2$ and other ROS, and protect cellular membranes against ROS. Fractions of Euphorbia humifusa extracts can be applicable to new functional cosmetics for antioxidant.

• Journal of Korean Vacuum Science & Technology
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• v.6 no.2
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• pp.105-107
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• 2002

a-C:H films were coated on windows of mobile telephone by RF plasma chemical vapor deposition equipment made in our company. Thickness of the coatings is about 0.7 micrometers and they have high hardness, low friction coefficient, good adhesion, high optical transparency and chemical inertness. Knoop hardness of the diamond-like carbon films on glass substrate is 2328 kg/mm$^2$. The adherence between films and substrate is good and shows to be 69 N by scratching test. The optical performance is improved obviously owing to coat the film on it. The index of the coated windows is 2.5, transmission of visible light is larger than 90%, and transmission of ultraviolet light decreases by 30% and the ultraviolet light can be obstructed obviously. The coated glass also has self-clean effect and decontamination ability. The films have hydrophobic character and the soakage angle of water drop is larger than 90 degrees. The windows have fog-proof ability owing to eliminate the capillary phenomena in the inner surface. The physics and chemical properties of the coated windows are steady. Study indicates that the performance of a-C:H coated mobile phone windows are improved notably on wear-resistance, corrosion-proof and optical properties and it is excellent mobile windows protective coatings.

• Textile Coloration and Finishing
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• v.29 no.3
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• pp.131-138
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• 2017

Most of high performance fabrics for the car racing protective clothing have been developed to have thermal resistance, flame retardant property, impact resistance and anti-frictional properties to protect the racer from the crucial accident. In this study, the meta-aramid fabric, which has inherent flame retardant, was coated with nanoparticles of SiC to enhance the impact resistance and anti-friction properties. Uniform coating of the nanoparticles onto the fabrics was obtained by using tape casting method. As the experimental parameters, size and content of the SiC nanoparticle were varied with the coating conditions of the fabric surface. The effects of the nanoparticle coating on the properties of meta-aramid fabric were examined with various instrumental analyses such as SEM, tensile strength and abrasion test.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.5
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• pp.58-64
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• 2012

In electric power supply systems, an earthing system determines the electric potential of the conductors related to that of the Earth's surface. The choice of earthing system has implications for the safety of the power supply systems. There are considerably different regulations for earthing (grounding) systems in each country. A protective earth(PE) conductor ensures that all exposed conductive surfaces are at the same electric potential as the earth surface. This paper deals with that when PEN conductor of TN-C-S system is disconnected, dangerous touch voltage causes personnel body to be harmed and human being's property to be damaged seriously. For this reason, this paper explains how serious problems can occur when the fault current flows. As a consequence, we can understand how we can design earthing system properly to ensure the personnel safety against earth faults. The result shows the way that TN-C-S system can be applied safely in Korea.

• Journal of the Korean Society of Clothing and Textiles
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• v.42 no.3
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• pp.516-529
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• 2018

This study investigated the dyeing properties and bio-functions of cotton fabrics dyed with naturally fermented Ecklonia cava extract in order to compare it with a comparison of unfermented extract. Hot water-extracted Ecklonia cava was fermented naturally under the various conditions of a fermenting period (2-8 days) and amount of molasses (0.1-1.8% v/v); in addition, it was also tested for characterization by FT-IR, antioxidant activity, total polyphenol content, and anti-microbial activity. For dyed cotton fabrics, color strength (K/S), physical color properties, dyeing fastness, sun protective property, and anti-microbial activity were evaluated considering dyeing conditions. As a result, the fermented dye under fermentation condition of 0.1% v/v with molasses during 4 days was revealed as having a similar chemical structure to the unfermented one and showed a total polyphenol content with 32.88mg/g and better antioxidant activity than the unfermented one. As for dyed fabrics, the color strength value by K/S was the highest under the condition of 0.1% v/v of molasses during 4 days among all fermenting conditions. The dyed fabrics had a reasonably good fastness (except for light). Anti-microbial activity against K. pneumoniae was better for the fermented extract-dyed fabric especially with lower dye concentrations.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.8
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• pp.1179-1186
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• 2010

The antiradical property of hot water extract from dried radish (DR) or dried radish roasted with pressure (DRRP) was investigated in vitro and in LLC-PK1 cell system. The contents of total free amino acid and reducing sugar in DR were decreased by 72.86% and 3.17%, respectively, after pressurized roasting. In vitro test, $IC_{50}$ for DR and DRRP for DPPH radical scavenging activity were 646.70 and $135.45\;{\mu}g/mL$, 896.10 and $566.98\;{\mu}g/mL$ for superoxide anion radical, and 722.26 and $531.84\;{\mu}g/mL$ for hydroxy radical, respectively. The radical scavenging effects of DRRP was significantly greater than those for DR (p<0.001). These radical scavenging effects of DR and DRRP were confirmed in LLC-$PK_1$ at which oxidative stresses were induced by superoxide, nitric oxide and peroxynitrite generated in the treatment of pyrogallol, SNP, and SIN-1, respectively. Cell viability was increased in the presence of DR or DRRP, dose dependently (p<0.05), and TBARS formation was decreased. The protective effects of DRRP against oxidative damage in LLC-$PK_1$ were greater than those of DR at the same concentration tested (p<0.05). This superior antiradical activity of DRRP might be due to the products produced during the pressurized roasting in addition to the antioxidative compounds originally present in the radish. 5-hydroxyl methyl furfural (5-HMF) known as an intermediate product of the maillard reaction was detected in DRRP (0.57 mg/g), but not from DR. In conclusion, daily consumption of DRRP may prevent oxidative damage by retarding oxidative stress.