• Korean Journal of Agricultural Science
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• v.13 no.2
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• pp.279-288
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• 1986

One hundred and fifty one mutant strains were obtained from the parent strain Aspergillus oryzae MF by ultra-violet ray irradiation. Among those mutants a strain, Asp. oryzae UM-36 which hyperprodued protease, was selected and its morphological characteristics and the production of enzymes protease, ${\alpha}$-amylase, and glucoamylase on wheat bran koji and on soy-sauce koji were studied. The results obtained were as follows 1. The selected mutant showed slower growth and weak sporulation on malt agar and on Czapek agar than the parent strain. 2. The conidiophores of the mutant were generally shorter than those of the parent when grown on malt agar. 3. Sectoring in colonies was not found when grown on malt agar and on Czapek agar. 4. The level of protease production by the mutant was increased approximately 1,4-fold higher on wheat bran koji and 2-fold higher on soysauce koji than by the parent. 5. The production of ${\alpha}$-amylase and glucoamylase by the mutant were also increased as compared with the parent on wheat bran koji and on soy sauce koji. 6. In the case of parent strain and mutant strain, the highest activity of protease appeared after three days in wheat bran medium at $30^{\circ}C$ incubation, but the highest activities of ${\alpha}$-amylase and glucoamylase appeared after two days.

• Korean Journal of Poultry Science
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• v.39 no.3
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• pp.241-244
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• 2012

This study was performed to analyze the generational transmission and the expression of the foreign gene in the GFP transgenic chickens. The transmission rate and the expression of the GFP gene was investigated from the GFP transgenic rooster (G2) as the first founder to the ninth (G8). Analysis of GFP expression in hatched chickens was used the UV lamp. When GFP was expressed in the wings, bill and legs of a chick, the bird only was selected as a transgenic chick. The average transmission rate of the overall transgenic was 38~58%. These results showed that the transmission of the GFP gene in the transgenic chickens in accordance with the laws of Mendel's continues to the next generation without gene silencing.

• Applied Chemistry for Engineering
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• v.9 no.5
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• pp.634-638
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• 1998

Monodisperse, spherical $PMSQ/TiO_2$ composite fine powders were prepared by modified sol-gel process where 300 nm $TiO_2$ fine powders were used as seed particles for hetero-condensation with hydrolyzed MTMS (Methyltrimethoxysilane). The reaction was carried out under $N_2$ atmosphere at ambient temperature using $NH_3$ as a catalyst. Methanol was used as a solvent. Powder was obtained by the filtration of the solution with a glass filter and washing with acetone. The stirring rate, reaction temperature, $[H_2O]/[MTMS]$ and $[MTMS]/[TiO_2]$ ratio were varied to investigate shapes and sizes of particles. Monodisperse particles of $1-2{\mu}m$ diameter were obtained with [MTMS]=0.2 M, $[NH_3]=0.6M$, $[H_2O]/[MTMS]=100$, $[MTMS]/[TiO_2]=10-50$ at ambient temperature with mild stirring condition. These composite particles had a contact angle of almost 180 degree contact angle with water, which proves their excellent hydrophobicity. The study of UV absorption spectra showed that they have UV protecting effect.

• Polymer(Korea)
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• v.36 no.1
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• pp.98-103
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• 2012

Poly(2,6-dimethyl-1,4-phenylene ether) (PPE) was synthesized using $Cu(NO_2)_2{\cdot}3H_2O$ or CuCl catalyst with various amounts of ligand and base in several different solvent systems. CuCl/1-methylimidazole/ammonium hydroxide was found to be an effective catalyst system which showed the highest polymer yield and molecular weight. The effects of catalyst/monomer ratio, different amine ligands, and the content of mono-functional reagent 2,4,6-trimethylphenol (TMP) additive on the polymer yield and molecular weight were investigated. Among the co-solvent systems used in this polymerization, chloroform/methanol 9/1(v/v) gave the highest polymer yield and molecular weight ($\overline{M_n}$ 55 K, $\overline{M_w}$ 92 K, PDI 1.7). The catalytic activity between CuCl and CuI was compared by oxygen-uptake experiments and the formation of sideproduct, 5,5'-tetramethyl-4,4'-diphenoquinone (DPQ), was analyzed by ultraviolet spectroscopy.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.6
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• pp.80-85
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• 2019

Vanadium dioxide is a well-known metal-insulator phase transition material. Lots of researches of vanadium redox flow batteries have been researched as large scale energy storage system. In this study, vanadium oxide($VO_x$) thin films were applied to cathode for lithium ion battery. The $VO_x$ thin films were deposited on Si substrate($SiO_2$ layer of 300 nm thickness was formed on Si wafer via thermal oxidation process), quartz substrate by RF magnetron sputter system for 60 minutes at $500^{\circ}C$ with different RF powers. The surface morphology of as-deposited $VO_x$ thin films was characterized by field-emission scanning electron microscopy. The crystallographic property was confirmed by Raman spectroscopy. The optical properties were characterized by UV-visible spectrophotometer. The coin cell lithium-ion battery of CR2032 was fabricated with cathode material of $VO_x$ thin films on Cu foil. Electrochemical property of the coin cell was investigated by electrochemical analyzer. As the results, as increased of RF power, grain size of as-deposited $VO_x$ thin films was increased. As-deposited thin films exhibit $VO_2$ phase with RF power of 200 W above. The transmittance of as-deposited $VO_x$ films exhibits different values for different crystalline phase. The cyclic performance of $VO_x$ films exhibits higher values for large surface area and mixed crystalline phase.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.5
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• pp.1-6
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• 2019

Organic dye-doped silica nanoparticles are used as a promising nanomaterials for bio-labeling, bio-imaging and bio-sensing. Fluorescent silica nanoparticles(NPs) have been synthesized by the modified $St{\ddot{o}}ber$ method. In this study, dye-free fluorescent silica NPs of various sized were synthesized by Sol-Gel process as the modified $St{\ddot{o}}ber$ method. The functional material of APTES((3-aminopropyl)triethoxysilane) was added as an additive during the Sol-Gel process. The as-synthesized silica NPs were calcined at $400^{\circ}C$ for 2 hours. The surface morphology and particle size of the as-synthesized silica NPs were characterized by field-emission scanning electron microscopy. The fluorescent characteristics of the as-synthesized silica NPs was confirmed by UV lamp irradiation of 365 nm wavelength. The photoluminescence (PL) of the as-synthesized silica NPs with different size was analyzed by fluorometry. As the results, the as-synthesized silica NPs exhibits same blue fluorescent characteristics for different NPs size. Especially, as increased of the silica NPs size, the intensity of PL was decreased. The blue fluorescence of dye-free silica NPs was attributed to linkage of $NH_2$ groups of the APTES layer and oxygen-related defects in the silica matrix skeleton.

• Korean Journal of Food Science and Technology
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• v.53 no.4
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• pp.501-508
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• 2021

The purpose of this study was to evaluate the application of ATP bioluminescence assay for effect assessment of hygiene visiting education on children's foodservice facilities in the local small town. The sanitary inspection results of the hygiene visiting education showed significant improvement in all items except 'To regularly disinfect cooking facilities, storage rooms, etc.' ATP bioluminescence analysis was performed on cooking utensils to evaluate the educational effect, and the results showed a correlation with the effect in most items. In the case of knives and cutting boards, all facilities showed a value of 20 RLU/cm² or less after the educational support, and in particular, it was approximately 10 RLU/cm² or less in national/public, corporation and private facilities. Correlation analysis between the post-education sanitary inspection results and ATP values for three items related to knives and cutting boards showed that they have a negative and high correlations.

• 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.

• Korean Journal of Plant Resources
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• v.37 no.2
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• pp.101-109
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• 2024

In this study, we investigated the antioxidant effects and active ingredients of Gynura Procumbens extracts obtained through various extraction methods for the development of natural-based cosmetics and pharmaceutical materials. The contents of compounds, total flavonoids, chlorogenic acid, and caffeic acid were compared at different concentrations, revealing the highest content of active ingredients in the 100% ethanol extract. Antioxidant activity assessed by DPPH and ABTS radical scavenging assays showed a concentration-dependent increase in antioxidant activity with the ethanol concentration. Additionally, we validated the DNA damage inhibition and anti-inflammatory effects of Gynura Procumbens extracts through UVB irradiation on Hs68 cell models. The 100% ethanol extract demonstrated significant inhibition of the expression of p-p53, γ-H2AX, iNOS, and COX-2 induced by UVB, indicating its potential in alleviating photodamage effects. Consequently, the efficient extraction of Gynura Procumbens for skin functional material development was confirmed, suggesting the suitability of ethanol or alcohol-based solvents.

• Journal of the Korea Institute of Military Science and Technology
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• v.11 no.2
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• pp.136-143
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• 2008

A three-wavelength solar bank is a very important part for a solar simulator with commercial superlux lamps. It is projected metal halide lamps to satisfy following points simultaneously: $\pm$10% of uniformity for irradiance of target area and irradiance in each wave region, and $1,232W/m^2$ of maximum solar irradiance in summer. The developed solar lamp bank has been analyzed numerically by commercial programs in this study to carry out experiments. In conclusion, designed B-type heat lamp is not concentrated in one place than designed A-type heat lamp, it is spreaded widely, and it was proved numerical computation. We suggest that solar simulator is applied to actual experiment test through heat flow numerical analysis in solar lamp bank and the lamp is applied private industry or the military using complex environmental assessment test.