• Journal of Sericultural and Entomological Science
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• v.28 no.1
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• pp.72-78
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• 1986

The studies were performed to investigate the optimum conditions for tannic processing of silk by use Chinese Gallotannin and synthesized tannic acid, which are aimed at weighting, dyeing and physical properties of tannin treated silk. 1. It was reasonable that the concentration of tannin solution is 30 grams per liter of Chinese Gallotannin, 15 grams per liter of tannic acid for the efficient weighting of processed silk. The temperature and time for tannin treatment was optimum at 80$^{\circ}C$, 60 minutes and the acidity of tannin solution at pH 2 to 3. 2. In dyeing the tannintreated silk by Acid dye Orange II, the temperature and time was reasonable at 60$^{\circ}C$, 90 minutes to control the desorption of tannin components weighted onto silk. 3. The colour differences ($\Delta$E) of dyed silk fabric by soaping could be remarkably narrowed by tannin treatment, resulting in improving the washing fastness of tannin treated silk by two grades more than that of untreated one. 4. The light fastness of tannin treated silk could be drastically improved by reducing the dye-loss of dyed silk fabric which was coused from the Ultra-violet ray irrdiation. 5. The rubbing fastness and water repellency of tannin treated silk was at the same level with that of untreated one. However, the Drape coefficient of tannin treated silk was decreased more than that of untreated one, which is closely related with fabric softness and dressing appearence.

• Journal of Dental Rehabilitation and Applied Science
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• v.37 no.3
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• pp.111-122
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• 2021

Purpose: The purpose of this in vitro study was to investigate the flexural strength and translucency of three layers in 5Y-ZP and to assess the effect of additional firings on these properties. Materials and Methods: Sintered zirconia blocks were sectioned according to three layers : incisal, transition, and body. Disc-shaped specimens were fabricated from each layer. The diameter of specimens was 15.0 mm and each thickness of specimens for biaxial flexural strength test and translucency was 1.2 mm and 1.0 mm. The specimens were classified into subgroups according to the number of firing (0, 1, and 3 times; n = 10/subgroup) and the additional firings were performed under 900℃ using a furnace. Biaxial flexural strength and translucency was measured using universal testing machine and uv-vis spectrophotometer. X-ray diffraction (XRD) analysis was used for measurement of the phase identification. One-way ANOVA, Tukey HSD test were performed (α = 0.05). Results: There was no significant difference in flexural strength between the three layers (P > 0.05), while there was significant difference in translucency between different layers (P < 0.05). The flexural strength of incisal and transition layer was decreased by the single additional firing, and the three additional firings significantly decreased the flexural strength of three layers. The translucency of layer was decreased by additional firings except the body layer. The XRD patterns of all groups were similar. Conclusion: Three layers of 5Y-ZP were different only in translucency. Additional firings affected the flexural strength and translucency differently depending on the layers but crystalline phases were not changed.

• Journal of the Microelectronics and Packaging Society
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• v.26 no.2
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• pp.15-21
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• 2019

We investigated the structural, electrical and optical properties of zinc oxide (ZnO) ultra-thin films grown at $150^{\circ}C$ by atomic layer deposition (ALD). Diethylzinc and deionized water were used as metal precursors and reactants, respectively, for the deposition of ZnO thin films. The growth rate per ALD cycle was a constant 0.21 nm/cycle at $150^{\circ}C$, and samples below 50 cycles had amorphous properties due to the relatively thin thickness at the initial ALD growth stage. With the increase of the thickness from 100 cycles to 200 cycles, the crystallinity of ZnO thin films was increased and hexagonal wurtzite structure was observed. In addition, the particle size of the ZnO thin film increased with increasing number of ALD cycles. Electrical properties analysis showed that the resistivity value decreased with the increase of the thin film thickness, which is correlated with the decrease of the grain boundary concentration in the thicker ZnO thin film due to the increase of grain size and the improvement of the crystallinity. Optical characterization results showed that the band edge absorption in the near ultraviolet region (300 nm~400 nm) was increased and shifted. This phenomenon is due to the increase of the carrier concentration with the increase of the ZnO thin film thickness. This result agrees well with the decrease of the resistivity with the increase of the thin film thickness. Consequently, as the thickness of the thin film increases, the stress on the film surface is relaxed, the band gap decreases, and the crystallinity and conductivity are improved.

• Korean Journal of Heritage: History & Science
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• v.46 no.4
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• pp.78-89
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• 2013

For safe conservation treatment of damaged accessory relics that were unearthed, the quality of the material should be accurately identified through a nondestructive analysis and failure analysis. This study provides the basic conservational scientific data regarding material analyses and conservation treatment that were conducted for 11 relics, including amber and agate that were discovered during the repair of Geumsansa Temple's Hall of Maitreya Buddha and Left Attendant Buddhas in June 2008. An ultraviolet analysis, SEM-EDS analysis and FT-IR microscope analysis revealed that the physical and chemical characteristics of the 11 relics are the same as those of amber. It is inferred that the cracks and exfoliation of the surface of most amber relics is attributable to darkening of the color due to C=C bond oxidation. It is also assumed that cracks and exfoliation occurred from the weathered layer on the amber surface. As such, it is appropriate to engage in conservation treatment of the damaged amber relics by using $Paraloid^{(R)}$ B67 reinforcing agent that is diluted in nonpolar solvent. The greatest care is needed for future handling of organic artifacts.

• Journal of Physiology & Pathology in Korean Medicine
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• v.33 no.3
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• pp.175-180
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• 2019

Torilis Japonica (TJ) has been used as an anti-allergy, antifungal, and antibacterial agent. Recent studies have reported that it also shows anti-cancer effects. It is report that TJ inhibits melanin synthesis in melanocyte in the skin. However, the effect and mechanism of TJ extract (TJE) on Ultraviolet (UV)B-induced photoaging are unknown. In this study, we investigated the preventive effects of TJE on matrix metalloproteinase (MMP)-1 and MMP-3 expressions and the underlying molecular mechanism in UVB-irradiated primary human dermal fibroblasts (HDFs). The effect of TJE on HDF cell viability was determined using the XTT assay and cell counting. MMP-1 and MMP-3 expressions levels were measured by western blotting and real-time PCR analysis. Activations of mitogen-activated protein kinase (MAPKinase), nuclear $factor-{\kappa}B$ ($NF-{\kappa}B$), and activator protein-1(AP-1) were measured by western blotting. Our results showed that TJE effectively reduced UVB-induced MMP-1 and MMP-3 protein and mRNA levels. Moreover, TJE significantly blocked the UVB-induced activation of MAPK (p38 and JNK) and transcription factors ($NF-{\kappa}B$ and AP-1), but not ERK. Taken together, our results suggest that the TJE inhibits UVB-induced MMP expressions in HDFs and its may be a potential agent for the prevention and treatment of skin photoaging.

• Microbiology and Biotechnology Letters
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• v.50 no.2
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• pp.165-192
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• 2022

The microbial metagenome characteristics of bioaerosols and particulate matter (PM) in the outdoor atmospheric environment and the effects of climate and environmental factors on the metagenome were analyzed. The concentrations of bacteria and fungi in bioaerosols and PM were determined by sampling different regions with different environmental properties. A variety of culture-independent methods were used to analyze the microbial metagenome in aerosols and PM samples. In addition, the effects of meteorological and environmental factors on the diversity and metagenomes of bacteria and fungi were investigated. The survival, growth, and dispersal of the microorganisms in the atmosphere were markedly affected by local weather conditions and the air pollutant concentration. The concentration of airborne microorganisms increased as the temperature increased, but their concentration decreased in summer, due to the effects of high temperatures and strong ultraviolet rays. Humidity and microbial concentration were positively correlated, but when the humidity was too high, the dispersion of airborne microorganisms was inhibited. These comprehensive data on the microbial metagenome in bioaerosols and PM may be used to understand the roles and functions of microorganisms in the atmosphere, and to develop strategies and abatement techniques to address the environmental and public health problems caused by these microorganisms.

• Research in Plant Disease
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• v.28 no.2
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• pp.61-68
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• 2022

Powdery mildew and two-spotted spider mite are detrimental to strawberry plants and are controlled with traditional pesticides. To accommodate consumer demand, eco-friendly methods of pest control are required. Strawberries were cultivated (in soil and in a hydroponic system) for two years, and ultraviolet B (UV-B) irradiation was used as an alternative pest control during the harvesting season. Three varieties were grown (Seolhyang, Kingsberry, and Durihyang), and four UV-B lamp/mulch (black, green, and light reflection sheet [LRS]) combinations were used during harvesting: UV-B+black or green mulch, UV-B+black or green+LRS, no UV-B+black or green, and no UV-B+black or green+LRS. In all varieties, powdery mildew was 65% more controlled when UV-B irradiation was used. The adult two-spotted spider mite density was lowest in the UV-B lamp+black or green+LRS treatments. Therefore, UV-B irradiation during the strawberry harvesting season could effectively control powdery mildew and two-spotted spider mite with little side effect on the plants.

• Journal of the Microelectronics and Packaging Society
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• v.30 no.2
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• pp.65-70
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• 2023

Nanoimprint lithography (NIL) has attracted much attention due to its process simplicity, excellent patternability, process scalability, high productivity, and low processing cost for pattern formation. However, the pattern size that can be implemented on metal materials through conventional NIL technologies is generally limited to the micro level. Here, we introduce a novel hard imprint lithography method, extreme-pressure imprint lithography (EPIL), for the direct nano-to-microscale pattern formation on the surfaces of metal substrates with various thicknesses. The EPIL process allows reliable nanoscopic patterning on diverse surfaces, such as polymers, metals, and ceramics, without the use of ultraviolet (UV) light, laser, imprint resist, or electrical pulse. Micro/nano molds fabricated by laser micromachining and conventional photolithography are utilized for the nanopatterning of Al substrates through precise plastic deformation by applying high load or pressure at room temperature. We demonstrate micro/nanoscale pattern formation on the Al substrates with various thicknesses from 20 ㎛ to 100 mm. Moreover, we also show how to obtain controllable pattern structures on the surface of metallic materials via the versatile EPIL technique. We expect that this imprint lithography-based new approach will be applied to other emerging nanofabrication methods for various device applications with complex geometries on the surface of metallic materials.

• Journal of Food Hygiene and Safety
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• v.38 no.5
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• pp.287-296
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• 2023

Mushroom consumption is gradually growing annually worldwide for many centuries. Oyster mushrooms (Pleurotus ostreatus), button mushrooms (Agaricus bisporus), and enokitake (Flammulina filiformis) are mainly consumed in Korea. However, mushrooms can be contaminated with pathogenic microorganisms, such as Listeria monocytogenes, because antibacterial treatment during mushroom cultivation and processing is insufficient. Therefore, many cases of mushroom contamination-related foodborne illnesses and food recalls have been reported. Three representative treatments are used to prevent microbial contamination in mushrooms: chemical, physical, and combination treatments. Among the chemical treatments, chlorine compounds, peroxyacetic acid, and quaternary ammonium compounds are commercially used and ozone and electrolyzed water has recently been used. Additionally, physical treatments, including ultrasound, irradiation, and cold plasma, are being developed. Combination techniques include ultraviolet/chlorine compounds, ozone/organic acid, and ultrasound/organic acid. This review describes the domestically consumed mushroom types and their characteristics, and investigates the mushroom contamination levels. Additionally, effective antibacterial technologies for reducing microbial contamination in mushrooms are also discussed.

• Applied Biological Chemistry
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• v.20 no.1
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• pp.66-80
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• 1977

This research was carried as a part of the basic study, in which the aptitude of theKorean oak varieties as barrels for aging apple fine spirits was investigated, and thefollowing results were obtained. 1. Following was the result of the chemical analysis of the fruits which are now mass-produced and can be used as a substitute for raw materials for wine production. Apple (Malus pumila Miller var. domestica Schneider) : Total sugar. total acid, volatile acid and pectin of Jonathan (Hong-og) were 13.95%, 0.46%, 0.012%, 0.20% respectively. Total sugar, total acid, volatile acid and pectin of Ralls (Koog-kwang) were 13.35%, 0.43%, 0.011%, 0.45% respectively. 2. Because of low yield of apple juice due to cellulose, pectin, hemicellulose which are present besides sugars, acids in apples, the apple juice were treated with xylanase of Aspergillus niger SUAFM-430, cellulase and pectinase of Aspergillus niger SUAFM-6. This treatment increased the yield of apple juice. And the apple juice was sterilized by adding potassium metabisulfite $(K_2S_20_5)$ and Saccharomyces cerevisae var. ellipsoideus Rasse Johannisberg II (SUAFM-1018) as a cultivation yeast, which has a strong fermentation power was used to ferment. The yield of apple wine based on raw material was 86-87%. The amount of ethanol, extract and methanol obtained from Jonathan and Ralls were 13.5%, 5.4%, 0.04-0.05% respectively. 3. Wines were distilled for two times by the pot still method to make fine spirits. The yield of fine spirits from apple wine mash was 86.6%, and the pH of fine spirits from Jonathan and Ralls were 4.1, 4.2 respectively. 4. The oak chips made of inner part or outer part of 24 Korean oak varieties were used to select the barrel for aging fine spirits. Two oak chips (one oak chip: $1{\times}1{\times}5cm$) of the inner part or of the outer part of each oak variety were dipped into 300 ml of fine spirits, which was bottled in 640ml beer bottle, and followed aging. The colors, flavors and tastes of the fine spirits were checked during 6 months. A. As a criterion for the first screening of oak barrels for aging fine spirits, the rate five of color extraction was determined. The oak chips showed good results in their order as follows and the best 5 varieties were selected. Gal-cham: Quercus aliena Blume (Inner part), Gul-cham: Quercus variabilis Blume (Outer part), Gal-chain: Quercus aliena Blume (Outer part), Jol-cham: Quercus serrata Thumb (Inner and Outer part). Sin-gal-cham: Quercus mongolica Fisher (Outer and Inner part) Sang-su-ri: Quercus acutissima Carruthers (Outer and Inner part) B. To find out the influence of aging temperature on aging, apple fine spirits were aged by dipping each oak chip at room temperature $(24-25^{\circ}C)$) and $45^{\circ}C$. Aging at $45^{\circ}C$ gave the best result followed aging at $30^{\circ}C$ and then at room temperature. C. Apple fine spirits was aged for six months by dipping oak chips in Erlenmeyer flasks and was irradiated with U.V light. The U.V irradiation enhanced the aging effect by nearly two times, compared with the aging without U.V irradiation. D. In aging apple fine spirits by dipping two oak chips, it was observed that the extent of the extraction of most components of oak chips were strongly dependent upon the pH of fine spirits. E. Oak chips of five selected oak varieties and a Limousin white oak from France as a control were used. Each apple fine spitits was dipped by two oak chips, and was aged at room temperature $(24-25^{\circ}C)$, $30^{\circ}C$, $45^{\circ}C$, and with the U.V irradiation at room temperature shaking every week. After six months of aging, the panel test of these aged fine spirits (Young Brandy) showed the following result. Young brandy of apples aged at $45^{\circ}C$ by dipping oak chips of Gal-chain was almost as the fine spirits which were aged at room temperature by dipping Limousin white oak chips from France. Young brandy of with U.V. irradiation at room temperature which were aged by dipping oak chips of Gal-chain was a little worse than that from the fine spirits aged at room temperature by dipping Limousin white oak chips from France. And so, Korean oak varieties are thought to be able to be used for aging every apple fine spirit which was here investigated.