• Korean Journal of Food Science and Technology
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• v.47 no.6
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• pp.733-737
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• 2015

For testing the ultraviolet (UV)-blocking property of functional films coated with Nano-$TiO_2$ particles, UV-Vis spectra of oriented polypropylene (OPP) films uncoated and coated with $TiO_2$ of 3% and 5% in Polyurethane (PU) and polyvinyl butyral (PVB)-Cellulose binders were measured. The result of UV-Vis analyses showed that the film coated with 5% $TiO_2$ in PVB binders had a significant effect on UV protection of 90% compared with the film uncoated. Also The result of The photodegradation of methylene blue (MB), OPP films coated with 5% in both PU and PVB binders had a high photocatalytic activity for MB degradation. To evaluate the effect of the developed functional film coated with Nano-$TiO_2$ particles, fresh soybean sprouts were used. Nano-$TiO_2$ coated film was observed to decompose the off-flavor produced by soybean sprouts within packages during distribution, but uncoated film did not. Therefore, Nano-$TiO_2$ coated film package could give the greatest effect in extending the shelf life of soybean sprouts.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.24 no.1
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• pp.1-11
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• 2018

In this study, pro-oxidant($d2w^{(R)}$) and rPP/ZnO nanocomposite flexible films for food packaging were prepared, and their mechanical and antimicrobial properties were investigated. As a result, the carbonyl index and hydroxyl index increased with exposured time to heat and UV rays. Surface analysis showed that the addition of zinc oxide improved the dispersibility and compatibility of the polymer, so that the surface of the composite film was smooth and the zinc oxide particles were smaller than the compared film. And it kept the physical properties by heat and UV ray blocking effect, and it worked to reduce decomposition. In the antimicrobial activity test, the microbial reduction rate was 3 logs or more at the use concentration of zinc oxide. The tensile strength was increased and the elongation was decreased. Oxidative degradability of multi-layered film in UV exposured for 72 hours, the molecular weight of the film decreased by 75.6%, 1,294 g/mol Mn and 5,920 g/mol Mw. In the safety analysis of food packaging materials, we obtained that are in standard of polypropylene, a food contact material of domestic law.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.5
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• pp.363-371
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• 2019

In this study, 340 Korean women were surveyed to analyze the impact of the type of sunscreen and use status on the satisfaction of products and resale. Studies have shown that indoor activity is higher than outdoor activity, and both simple and complex sunscreen is often used to compensate for skin tone. Out of single sunscreen, sun cream was used and air cushion was used a lot. Although product usability and UV protection indices were important factors in purchasing, 30% experienced side effects while product satisfaction and willingness to repurchase were high. The recognition of safety, Effectiveness, convenience, usability, satisfaction, and repurchase were all higher than that of composite UV-blocking products, and among subcomponents of product usage recognition, the level of convenience, efficacy, usability, and safety affected satisfaction and repurchase in order. Consequently, the perception of simple UV protection products was higher when using products for UV protection, and its convenience had a significant impact on satisfaction and resale.

• Toxicological Research
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• v.21 no.2
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• pp.99-105
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• 2005

Photo-mutagenic compounds have been known to alter skin cancer rates by acting as initiators or by affecting subsequent steps in carcinogenesis. The objectives of this study are to investigate the utility of photo-chromosomal aberration (photo-CA) assay for detecting photo-clastogens, and to evaluate its ability to predict rodent photocarcinogenicity. Photo-CA assay was performed with five test substances that demonstrated positive results in photo-carcinogenicity tests: 8-Methoxypsoralen (photoactive substance that forms DNA adducts in the presence of ultraviolet A irradiation), chlorpromazine (an aliphatic phenothiazine an alpha-adrenergic blocking agent), lomefloxacin (an antibiotic in a class of drugs called fluoroquinolones), anthracene (a tricyclic aromatic hydrocarbon a basic substance for production of anthraquinone, dyes, pigments, insecticides, wood preservatives and coating materials) and Retinoic acid (a retinoid compound closely related to vitamin A). For the best discrimination between the test substance-mediated genotoxicity and the undesirable genotoxicity caused by direct DNA absorption, a UV dose-response of the cells in the absence of the test substances was firstly analyzed. All 5 test substances showed a positive outcome in photo-CA assay, indicating that the photo-CA test is very sensitive to the photo-genotoxic effect of UV irradiation. With this limited data-set, an investigation into the predictive value of this photo-CA test for determining the photo-carcinogenicity showed that photo-CA assay has the high ability of a test to predict carcinogenicity. Therefore, the photo-CA test using mammalian cells seems to be a sensitive method to evaluate the photo-carcinogenic potential of new compounds.

• The Korean Journal of Community Living Science
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• v.28 no.1
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• pp.143-154
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• 2017

This study was conducted to develop fabrics using non-toxic and eco-friendly natural dyes made from curcuma and coffee extract. The natural dyes were applied to non-printed cotton fabrics using the dip dyeing method, and the pattern was hand-printed onto the dyed fabrics to make dyed printed-fabrics. The four types of developed fabric samples were compared to analyze the effects of the dyeing materials and printing on the hygienic properties of curcuma- and coffee-dyed fabrics. The findings were as follows. First, air permeability of both curcuma- and coffee-dyed fabrics was greatly affected by the presence of patterns, although the type of dye did not seem to have an effect. Printing greatly reduced air permeability of the fabric, and coffee-dyed fabric showed greater reduction of dyeing method than curcuma-dyed fabric. Moisture regain also tended to decrease with printing, but the change was much smaller compared to air permeability. Second, increased UV blockage was observed in curcuma- and coffee-dyed fabrics with patterns compared to non-printed fabrics, showing that printing enhanced UV blocking. Third, deodorization rate tended to increase sharply for both curcuma- and coffee-dyed fabrics until 30 minutes and gradually increased thereafter to yield 30% for curcuma and 50% for coffee at 120 minutes, demonstrating higher deodorization of coffee dye. Coffee-dyed fabric showed an antibacterial rate about twice as high as that of curcuma-dyed fabric, and the observed data suggest that curcuma-dyed fabric had an insignificant level of antibiosis. Fourth, printing significantly enhanced wash, sunlight, and compound colorfastness of the two types of dyed fabrics. The effect of printing was most dramatic on sunlight and compound colorfastness, which are aspects in which natural dyed fabrics perform poorly in general. Eventually, the development and application of biologically- and environmentally-friendly fabrics with natural dyes correspond with increased interest towards the wellness and healthy attitudes of modern society.

• Journal of Microbiology and Biotechnology
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• v.30 no.10
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• pp.1567-1573
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• 2020

Ultraviolet (UV) is one of the major factors harmful to skin health. Irradiation with ultraviolet accelerates the decline of skin function, causing the skin to have deep wrinkles, dryness, decreased procollagen production, and degradation of collagen. Novel materials are needed to prevent the aging of the skin by blocking the effects of UV. Safflower seed oil (Charthamus tinctorius L., SSO) contains significantly high levels of unsaturated fatty acids and phytochemicals. SSO has been traditionally used in China, Japan, and Korea to improve skin and hair. Our objective in this study was to determine the effect of SSO and its active compound acacetin on UVB-induced skin photoaging in HaCaT cells and human dermal fibroblasts (HDF). SSO inhibited UVB-induced matrix metalloproteinase-1 (MMP-1) at both protein and mRNA levels in HaCaT cells and HDF. MMP-1 is known to play important roles in collagen degradation and wrinkle formation. Acacetin, a type of flavonoid, is present in SSO. Similar to SSO, acacetin also inhibited UVB-induced MMP-1 protein and mRNA levels in HaCaT cells and HDF. MMP-1 mRNA is primarily regulated by the mitogen-activated kinase (MAPK) signaling pathway. Acacetin regulated the phosphorylation of JNK1/2 and c-jun, but did not inhibit the phosphorylation of ERK1/2, p38 and AKT. Taken together, these results indicate that SSO and its active compound acacetin can prevent UVB-induced MMP-1 expression, which leads to skin photoaging, and may therefore have therapeutic potential as an anti-wrinkle agent to improve skin health.

• Atmosphere
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• v.21 no.1
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• pp.123-130
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• 2011

In this study, we have analyzed the radiative characteristics of erythemal ultraviolet-B (EUV-B from 1999 to 2005) over the Korean Peninsula. EUV-B measured at Gangneung, Anmyondo, Mokpo, and Gosan represents the measurements from clean areas and that at Seoul represents from a polluted area. The magnitudes of EUV-B increase in proportion to the latitudinal decrease. Monthly mean variation of EUV-B at noon shows the maximum value of $158.5mWm^{-2}$ in August and the minimum value of $36.4mWm^{-2}$ in December in the clean areas. Seasonal mean diurnal variation of EUV-B shows a peak around noon (12:00 ~ 13:00 hr) and its intensity varies along with a season in order of summer > spring > fall > winter. The maximum value of $56.4mWm^{-2}$ in summer is three times higher than that in winter ($14.3mWm^{-2}$). The value of EUV-B in the polluted area is lower than that in the clean areas, resulting from the effects of the blocking, reflection, and scattering of EUV-B due to high concentrations of PM10. UV-B is an essential element to synthesize vitamin D in human body. 200 IU(International Unite) of vitamin D can be formed by an exposure of 6-10% of body surface area to 0.5 MED(Minimal Erythemal Dose). In order to form vitamin D, the calculated exposure times to EUV-B are 15 min. in spring, 12 min. in summer, 18 min. in fall, and 37 min. in winter for the clean areas and 16, 16, 24, and 37 min. for the polluted area.

• Elastomers and Composites
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• v.44 no.3
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• pp.290-298
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• 2009

In this paper, the Fe-activated carbon fiber (ACF)/$TiO_2$ composite catalysts were prepared by a sol-gel method. The synthesized photocatalysts were used for the photo degradation of Methylene blue solution under UV light. From Brunauer-Emmett-Teller measurements (BET) data, it was shown the blocking of the micropores on the surface of ACF by treatment of Fe and Ti compound. As shown in SEM images, the ferric compounds and titanium dioxides were fixed onto the ACF surfaces. The result of X-ray powder diffraction showed that the crystal phase contained a mixing anatase and rutile structure and the 'FeO+$TiO_2$' from the composites. The EDX spectra for the elemental analysis showed the presence of C, O, and Ti with Fe peaks. Degradation activity of MB could be attributed to +OH radicals derived from electron/hole pair's reactions due to photolysis of $TiO_2$ and photo-Fenton effect of Fe.

• Journal of Powder Materials
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• v.29 no.3
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• pp.207-212
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• 2022

Nanosized rutile titanium dioxide (TiO₂) is used in inorganic pigments and cosmetics because of its high whiteness and duality. The high quality of the white pigments depends on their surface coating technique via the solgel process. SiO₂ coatings are required to improve the dispersibility, UV-blocking, and whiteness of TiO₂. Tetraethyl orthosilicate (TEOS) is an important coating precursor owing to its ability to control various thicknesses and densities. In addition, we use Na₂SiO₃ (sodium silicate) as a precursor because of its low cost. Compared to TEOS, which controls the pH using a basic catalyst, Na₂SiO₃ controls the pH using an acid catalyst, giving a uniform coating. The coating thickness of TiO₂ is controlled using a surface modifier, cetrimonium bromide, which is used in various applications. The shape and thickness of the nanosized coating layer on TiO₂ are analyzed using transmission electron microscopy, and the SiO₂ nanoparticle behavior in terms of the before-and-after size distribution is measured using a particle size analyzer. The color measurements of the SiO₂ pigment are performed using UV-visible spectroscopy.

• Advances in nano research
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• v.15 no.4
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• pp.295-304
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• 2023

In this paper, a powerful photocatalyst based on carbon nanocomposite is developed in order to obtain a new material applicable in water treatment and especially for the discoloration of effluents used in the textile industry. For that, TiO₂-graphene nanocomposites have been successfully synthesized by a mixture of Functionalized Graphene Sheet (FGS) and tetrachlorotitanium complexes to form FGS-TiO₂ nanocomposite. In the presence of an anionic surfactant, we used a new chemical process to functionalize graphene sheets in order to make them an excellent medium for blocking and preventing the aggregation of TiO₂ nanoparticles. The components of these nanocomposites are characterized by means of X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM), which confirms the successful formation of the FGS-TiO₂ nanocomposite. It was found that the TiO₂ nanoparticles were dispersed uniformly on the graphene plane which possesses better charge separation capability than pure TiO₂. The FGS-TiO₂ nanocomposites exhibited higher photocatalytic activity compared to pure TiO₂ for the removal of three dyes: such as Methylene Blue (MB), Bromophenol Blue (BB) and Alizarin Red-S (AR) in water. The removal process was fast and more efficient with FGS-TiO₂ nanocomposite in daylight (in the absence of UV irradiation) compared to pure TiO₂ nanoparticles without and under UV in all pH range.