• The Research Journal of the Costume Culture
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• v.24 no.6
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• pp.817-824
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• 2016

The introduction of natural dyes into modern dye houses is very promising green chemistry concept that should be popularized more to reduce the dependency of leather dyeing on some toxic and non-biodegradable synthetic dyes. In this study, the properties of dyeing of cochineal on cow leather were evaluated. The proper dyeing conditions were identified with dye uptake (K/S values) depending on the colorant concentration, dyeing duration, dyeing temperature, and dye bath pH. For the proper mordanting conditions, color changes for different mordants were observed as $La^{*}b^{*}$ and H V/C values. Color fastness (light, rubbing, and dry cleaning) was also examined. Additionally, antibacterial properties and UV protection were examined. The results were as follows: The optimized dyeing conditions were 300% o.w.f., $40^{\circ}C$, 40 min., and pH 5. The cow leather color was red in the absence of mordanting, while it was red purple after being mordanted with Al and Cu, and purple mordanted with Fe. The K/S value of cow leathers increased in the order of the dyeing using $AlK(SO_4)_2$ > $CuSO_4$ > $FeSO_4$. The colorfastness to light and rubbing were reduced compared to original (untreated) cow leather. However dry cleaning fastness was very satisfactory, with a 4~5 rating. The dyed and pre-mordanting dyed cow leather showed excellent antibacterial properties.

• Journal of Ginseng Research
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• v.30 no.2
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• pp.82-87
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• 2006

Quantitative difference in five phenolic acids between white and red ginsengs was measured in this study. As the results, white ginseng has higher contents of cinnamic acid, quercetin and p-coumaric acid than red ginseng. Maltol was mainly included in red ginseng. These five compounds were recently reported to have tyrosinase inhibitory effects. These reports led us to investigate the de-pigmenting effect of ginseng products. In our examination of effect on tyrosinase activity, UV-protection and melanin production in melan-a cells, ethyl acetate traction of white ginseng extract and cinnamic acid showed potent de-pigmenting properties. The results indicated that white ginseng might be useful as skin whitening material and cinnamic acid proved to be one of active ingredient.

• Textile Coloration and Finishing
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• v.27 no.1
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• pp.80-95
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• 2015

In this study, the properties such as color, dye uptake and antibacterial function were examined through the application of combination dyeing and mixed dyeing with extracts from Humulus japonicus(hwansam) and the pruned branches of Prunus persica(peach) tree. In terms of dye uptake and surface color changes subject to the kind of mordants, methods and mixing ratio of dye, it was found that fabrics dyed by the pre-mordanting method with $CuSO_4$ showed the red green yellow group colors, which were not seen in fabrics dyed with hwansam only. Color fastness was found strong at grade 4-5 with 96.3% of UV protection ratio. While the fastness to light was as fair as grade 3, it showed an excellent result of 99.9% bacteria reduction rate against Staphylococcus aureus with fair 58% deodorization rate and 21.2% antibacterial rate against Klebsiella pneumoniae. As stated above, the combination and mixed dyeing resulted in the meaningful outcomes with regard to color variations, dye uptake, color fastness and functional properties.

• Journal of Life Science
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• v.23 no.4
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• pp.479-486
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• 2013

The DNA-binding protein from starved cells (DPS), originally identified as a DNA binding protein in Escherichia coli, is known to play an important role in DNA protection. The aim of this study was to evaluate the functional roles of DPS in E. coli against various kinds of external stresses by comparing the properties of wild-type E. coli cells and dps knockout mutant E. coli (${\Delta}dps$) cells. Under various stress conditions, we measured the cell growth of the wild-type E. coli and the dps knockout mutant E. coli (${\Delta}dps$) cells using a UV spectrophotometer. The growth rate of the cells was compared to investigate the functional roles of the DPS protein in E. coli. In comparison to the properties of the wild-type E. coli cells, the dps knockout mutant E. coli (${\Delta}dps$) cells showed highly sensitive phenotypes under various stress conditions, such as heat shock, acidic pH, nutrient deficiency, and different concentrations of reactive oxygen species (ROS), suggesting that DPS plays key roles in E. coli in combating diverse external stresses. The DPS DNA-binding protein in E. coli plays crucial roles in bacterial cell growth and in the protection of the cells from environmental stresses by tightly binding and preserving their DNA molecules.

• Applied Chemistry for Engineering
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• v.24 no.5
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• pp.499-506
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• 2013

As the usuage of tempered glass for touch panel increased rapidly with the development of industry, the amount of UV curable coating solution used to protect glass surfaces during a tempered glass manufacturing process increased as well. The UV curable coating has advantages compared to thermal curing such as shortened curing time and non-solvent. Appropriated polymer and monomer were used as an acid polymer to grant an alkali peeling ability. The monomers were 2-hydroxyl methylacrylate, 1,6-hexanediol diacrylate and dipentaerythritol hexaacrylate which have acryl groups of 1, 2, and 6, respectively. The combination of three different types of photoinhibitors were used and bisphenol A epoxy diacrylate was used as an oligomer. In this study, experiments were carried out by controlling the amount of photoinitiator, oligomer, and additive while maintaining the constant content of the acid polymer and the acrylic monomer. The changes in physical properties according to the additive content were investigated. It was found that the combination of photoinitiators was necessary to achieve the hardness above 4H and it was possible to control the delamination type of the coating film from a sheet to pieces by the addition of TPO as an initiator. The increase in oligomer contents increased the hardness and adhesiveness alongside dissection time. Talc content of 20 wt% showed the best results.

• Korean Journal of Materials Research
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• v.25 no.3
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• pp.125-131
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• 2015

Fluorine-doped $SnO_2$ (FTO) thin film/Ag nanowire (NW) double layers were fabricated by means of spin coating and ultrasonic spray pyrolysis. To investigate the optimum thickness of the FTO thin films when used as protection layer for Ag NWs, the deposition time of the ultrasonic spray pyrolysis process was varied at 0, 1, 3, 5, or 10 min. The structural, chemical, morphological, electrical, and optical properties of the double layers were examined using X-ray diffraction, X-ray photoelectron spectroscopy, field-emission scanning electron microscopy, transmission electron microscopy, the Hall effect measurement system, and UV-Vis spectrophotometry. Although pure Ag NWs formed isolated droplet-shaped Ag particles at an annealing temperature of $300^{\circ}C$, Ag NWs covered by FTO thin films maintained their high-aspect-ratio morphology. As the deposition time of the FTO thin films increased, the electrical and optical properties of the double layers degraded gradually. Therefore, the double layer fabricated with FTO thin films deposited for 1 min exhibited superb sheet resistance (${\sim}14.9{\Omega}/{\Box}$), high optical transmittance (~88.6 %), the best FOM (${\sim}19.9{\times}10^{-3}{\Omega}^{-1}$), and excellent thermal stability at an annealing temperature of $300^{\circ}C$ owing to the good morphology maintenance of the Ag NWs covered by FTO thin films.

• Ceramist
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• v.19 no.3
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• pp.26-35
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• 2016

The purpose of this study is to find the optimum conditions for manufacturing titanium dioxide using a hybrid self-assembly forming method, to confirm the shape, properties and synergy effect of UV protection for hybrid titanium dioxide. Hybrid titanium dioxide, manufactured by forming self-assembly of different sizes consisting of two kinds of titanium dioxides, has micro titanium dioxide (250nm~300nm) for support material, Nano titanium dioxide (20~30nm) for surface material, coating support material. Adjustment experiments of $AlCl_3$ concentration and both titanium dioxide ratio were conducted to find the optimized conditions for the surface coating of titanium dioxide striking a negative charge, a sample made of the optimized process was confirmed through an optical analysis, particle size analysis, and potentiometric analysis. The SPF in-vitro value of the cosmetics samples containing hybrid titanium dioxide showed 15~30% higher levels than the cosmetics samples containing both titanium dioxides mixture.

• Textile Coloration and Finishing
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• v.28 no.3
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• pp.219-229
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• 2016

The purpose of this study was to investigate the dyeability of silk fabrics with sweet potato stem leaf extract. To obtain the optimal dyeing conditions it was examined at various dyeing conditions(temperature, pH, time and bath ratio). The dyeability and the depths of shade which were evaluated in terms of K/S and CIELAB color difference values of the dyed and mordanted fabrics were also investigated. After dyeing, various color fastness(wash fastness, dry cleaning fastness, light fastness, rub fastness, and perspiration fastness) was measured and reviewed for UV protective, deodorant and antimicrobial functionality. The optimun output, as a result, was shown at 100% of dye concentration, $90^{\circ}C$ of dyeing temperature and 80 minutes of dyeing time while in terms of dye uptake depending on the kind of mordants and mordanting, it was found that among four mordants of $Alk(SO_4)_2$, $CuSO_4$, $SnCl_2$, and $FeSO_4$, post-mordanting with $SnCl_2$ showed the best results. Color fastness to dry cleaning, washing and rubbing was found strong at grade 4-5 and the grade to perspiration was as good as 3 while to light fastness was good at 4 as well. In aspects of functional properties, it showed excellent results of 98.3% UV protection rate and 88% deodorization rate. Antibacterial activity was 99.9% against staphylococcus aureus and 73.3% against klebisella pneumoniae. In conclusion, we validated that the dyestuffs from the disused sweet potato stem leaf extract would be useful as a natural dye material using the optimized conditions and dyeability for silk dyeing.

• Journal of Korean Ophthalmic Optics Society
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• v.10 no.1
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• pp.27-34
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• 2005

Photochromic lens is the color changing lens from colorlessness to colorness when exposed to UV light. It can protect eyes from UV-B light which cause the cataract and can be used as sunglass in the summer since it can cut off 70~80% of sun light. Surface coating technique was used to develop lens which has 70% light transmittance and of which fading time of color change is within 5 min. Various color lenses were developed so that these had various color such as blue, green, brown, violet, yellow and red etc. Lens has an excellent physical properties, 100% adhesion and 4~5H hardness. The chemical and the scratch resistance of this lens were the greatest and the thermal stability was also higher. The clinical trial of developed lens were applied to 65 patients who had photophobia by various reasons at ophthalmology of Soonchunhyang University Hospital. Results showed that glaring was significantly reduced and the visual health were remarkably improved. Especially, anti-glaring effect in the night was great for the patient who had the LASIK operation. Protection of UV-B and blue light also can prevent the patient from cataract and the yellowish crystalline lens at old ages. Through the result of clinical. trial, we know that photochromic lens could be a new technique for both cure and precaution of photophobia.

• Nuclear Engineering and Technology
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• v.53 no.6
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• pp.2025-2037
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• 2021

The influence of lead cations on natural quartz (QZ) from Egypt as a glass shielding material for the composition with nominal formula (10Na₂O - (90 - x) QZ - xPbO (where x = 30, 35, 40, 45 and 50 mol %)) was examined. The studied samples are synthesized via the melt quenching method at 1050 ℃. The X-ray diffraction XRD patterns were confirmed the glass nature for studied samples. Moreover, the optical properties, and the transparency for all compositions were examined by UV-Vis spectroscopy. Also, the major elemental composition of the natural quartz were estimated via the X-ray fluorescence (XRF) technique. Further, the density and molar volume were determined. Furthermore, the nuclear shielding parameters such as, mass attenuation coefficient, effective atomic number, electronic density, the total atomic, and electronic cross sections as well as the mean free path, and the half value layer with different gamma ray energies (81 keV-1407 keV) were calculated. Besides, the results showed that the shielding behavior towards the gamma ray radiation for all glass samples was increased as the increment in PbO concentration in the glass system.