• Korean Journal of Ecology and Environment
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• v.47 no.spc
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• pp.100-115
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• 2014

For this study, we collected fishes of seven times at the 51 sites by stream orders (2-6) from November 2007 to September 2010. In the results, 55 species belonging 12 families were collected. And there were one species (1.8%) of Natural monument, 6 species (10.9%) of endangered and 22 species (40.0%) of Korea endemic. Dominant species was Zacco koreanus and subdominant species was Zacco platypus in whole. Stream orders (2-6) increased with increasing species, diversity (H'), evenness (EI), richness (RI), tolerant (TS), omnivore (OS) and decreasing individual, dominance (DI), sensitive (SS) insectivore (IS), total IBI score. Principal component analysis results showed location of variable (species, individual, community index, relative abundance of tolerant, sensitive, omnivore, insectivore species) and each site changes in upstream and down-stream changes in their distribution. Correlation analysis showed significant differences between stream orders (2-6) and variable (species: Sp, diversity index: H', omnivore species: OS, stream depth: SD, stream width: SW and water temperature: WT).

• Nutrition Research and Practice
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• v.10 no.1
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• pp.11-18
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• 2016

BACKGROUND/OBJECTIVES: Type 2 diabetes (T2D) is more frequently diagnosed and is characterized by hyperglycemia and insulin resistance. $\small{D}$-xylose, a sucrase inhibitor, may be useful as a functional sugar complement to inhibit increases in blood glucose levels. The objective of this study was to investigate the anti-diabetic effects of $\small{D}$-xylose both in vitro and stretpozotocin (STZ)-nicotinamide (NA)-induced models in vivo. MATERIALS/METHODS: Wistar rats were divided into the following groups: (i) normal control; (ii) diabetic control; (iii) diabetic rats supplemented with a diet where 5% of the total sucrose content in the diet was replaced with $\small{D}$-xylose; and (iv) diabetic rats supplemented with a diet where 10% of the total sucrose content in the diet was replaced with $\small{D}$-xylose. These groups were maintained for two weeks. The effects of $\small{D}$-xylose on blood glucose levels were examined using oral glucose tolerance test, insulin secretion assays, histology of liver and pancreas tissues, and analysis of phosphoenolpyruvate carboxylase (PEPCK) expression in liver tissues of a STZ-NA-induced experimental rat model. Levels of glucose uptake and insulin secretion by differentiated C2C12 muscle cells and INS-1 pancreatic ${\beta}$-cells were analyzed. RESULTS: In vivo, $\small{D}$-xylose supplementation significantly reduced fasting serum glucose levels (P < 0.05), it slightly reduced the area under the glucose curve, and increased insulin levels compared to the diabetic controls. $\small{D}$-xylose supplementation enhanced the regeneration of pancreas tissue and improved the arrangement of hepatocytes compared to the diabetic controls. Lower levels of PEPCK were detected in the liver tissues of $\small{D}$-xylose-supplemented rats (P < 0.05). In vitro, both 2-NBDG uptake by C2C12 cells and insulin secretion by INS-1 cells were increased with $\small{D}$-xylose supplementation in a dose-dependent manner compared to treatment with glucose alone. CONCLUSIONS: In this study, $\small{D}$-xylose exerted anti-diabetic effects in vivo by regulating blood glucose levels via regeneration of damaged pancreas and liver tissues and regulation of PEPCK, a key rate-limiting enzyme in the process of gluconeogenesis. In vitro, $\small{D}$-xylose induced the uptake of glucose by muscle cells and the secretion of insulin cells by ${\beta}$-cells. These mechanistic insights will facilitate the development of highly effective strategy for T2D.

• Korean Journal of Optics and Photonics
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• v.13 no.5
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• pp.455-459
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• 2002

The transport and optical properties of $In_2O_3$:Zn(IZO) thin films grown by DC magnetron sputtering deposition have been studied. The deposition temperatures ($T_s$) were varied from room temperature to $400^{\circ}C$ in $50^{\circ}C$ steps. The IZO films are an amorphous phase for $T_s$<$300^{\circ}C$ and polycrystalline phase for $350^{\circ}C$＜$T_s$. In contrast to ordinary films, amorphous IZO films have lower resistivity and higher optical transmittance than polycrystalline IZO films. The resistivity of amorphous IZO was in the range of 0.29~0.4 m$\Omega$cm and that of polycrystalline IZO was in the range of 1~4 m$\Omega$cm. The carrier type for IZO film was found to be n-type, and the carrier density, was $3~5{\times}10^{20}/cm^3$. The Hall mobility, $({\mu}_H)$, was 20~$50\textrm{cm}^2$/V.sec. The predominant scattering mechanisms in both amorphous and polycrystalline IZO films were believed to be ionized impurity scattering and lattice scattering. The visible transmittance of the IZO films, which decreases with an increase of TS, was above 80%.

• The Korean Journal of Archival Studies
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• no.67
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• pp.5-55
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• 2021

The purpose of this study is to promote future research and practical application in the field of records systems by informing the revision of the ISO 16175 standard set and analyzing its main contents, which was widely used as a record management functional requirements. Based on the experience of participating in the developing process of this International Standard since 2015, this study analyzed the context and process of revision, and the main contents of the standard, and sought to draw limited implications and proposed follow-up researches connected to the practice of the Korean records systems. The previous ISO 16175 sets had been produced as ISO 16175-1, 2, 3 in 2010-2011, and which were restructured and revised into new ISO 16175-1, 2 in 2020 in line with the revision of ISO 15489 and changes in the digital environment. Main title of the International Standard is processes and functional requirements for software for managing records, and Part I provides high-level functional requirements and associated guidance for applications that manage digital records, Part II provides guidance for selecting, designing, implementing and maintaining software for managing records. This standard assumes that the records system does not necessarily have to be a single system or software solely for records management and that it should be able to perform record management function in any forms.

• Research in Plant Disease
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• v.30 no.2
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• pp.194-198
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• 2024

Pathogens of fire blight can survive for a long time on pruning tools, etc., and fire blight can be spread through agricultural implements. In particular, in Korea, pruning is frequently performed to remove flowers, immature fruits, and succulent shoots, and this farm work is known to be a major factor of the spread of fire blight. Therefore, in this study, in order to completely sterilize pathogens on pruning shears, we verified the disinfection effect of disinfectants distributed domestically and used them to identify an effective disinfection method. When disinfecting by immersion after inoculating Erwinia amylovora TS3128 on the scissor blade, 70% ethanol and 1% and 0.2% sodium hypochlorite sterilized immediately 10 sec after immersion, while 30% chlorine dioxide showed little disinfection effect. When disinfecting by spraying, 70% ethanol sterilized bacteria 1 sec after spraying, but 1% and 0.2% sodium hypochlorite disinfected bacteria after 10 and 60 sec, respectively. After cutting the naturally disease occurring branches five and 100 times, the bacteria were not hardly sterilized in immersion treatment in 70% ethanol for 30 sec but perfectly disinfected over 60 sec. Considering these results, pruning shears should be disinfected by frequently immersing them in 70% ethanol for at least 60 sec during pruning work in the field.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.1
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• pp.93-100
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• 2005

Comparative thickening and dewatering characteristics of municipal wastewater sludge were investigated in terms of separated and combined treatment of primary and secondary BNR sludge. Also, various conditioning methods such as cation polymer addition, steam and ultrasonication treatment were examined to improve dewaterability of sludge. The dewaterability was measured by using specific resistant test, wedge zone simulator and centrifuge. The result of the sludge thickening test revealed that separated thickening was better in terms of solids recovery and supernatant quality. Particularly, the thickening of primary sludge with high solids (about 3.5% TS) showed very poor solid separation. The addition of cation polymer showed better conditioning characteristic for dewatering and the optimal polymer dosage was 0.26% for primary sludge, 0.43% for secondary sludge and 0.38% for combined sludge. Contrary to the result of the thickening, the dewatering test revealed that dewatering of the combined sludge is better than that of separated sludge, representing better solids separation and filtrate quality. The polymer addition was essential to improve dewaterability in filter (belt) press type dewatering but it was inefficient for the dewatering of secondary sludge only. The centrifuge type dewatering showed better performance and the dewaterability was slightly improved when the polymer was added. Based on the results of this research a sustainable sludge treatment process, particularly in terms of the recycle water quality and solids recovery, was proposed.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.367-370
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• 2003

This study was carried out to investigate the possibility for reuse of solid organic wastes such as saccharified newspapers and boxes by two-phase anaerobic fermentation system. When 15g of newspaper and box wastes were digested for 24 days by batch fermentation, tCOD removal rate were found to be 60.9 and 62.4%, respectively. During this period, the amounts of biogas produced were 6.95 and 6.43L. The removal efficiencies of total solid were 34.8 and 33.4%, and those of volatile solid were 40.0 and 39.2%, respectively. That pH was around 7.5 after 20-days operation means methane fermentation is well advanced. In case of semicontinuous reaction, tCOD removal efficiencies of newspaper and box wastes were 64.7 and 65.0%, respectively for 14-days operation. It has been shown that each of the average biogas amounts produced after 25 days operation (stabilization stage for methane fermentation) was 0.31 and 0.30L/g dry wt./day, respectively, and each methane contents was 57.3 and 56.2%, respectively. After the reaction continued for 25 days, pHs in the anaerobic acidogenic and methanogenic fermenters were shown to be 5.0 and 7.5, respectively.

• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.2
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• pp.93-101
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• 2000

The objective of this study was to evaluate the possibility of co-digestion of food waste and sewage sludge mixture using anaerobic system. The Biochemical methane Potentials of cabbage and food waste were $297ml\;CH_4/g$ VS and $306.7ml\;CH_4/g$ VS, respectively. The biodegradability of food waste was 60%. The concentrations of acetate, propionate, and isobutyrate produced during the aerobic acidogenesis of food waste for 36 hours were 7,000~7,200 ppm, 260~280 ppm, 380~400 ppm, and 40~50 ppm, respectively, of which acetate was over 85%. The concentrations of acetate, propionate, and isobutyrate produced during the anaerobic acidogenesis for 36 hours were 1,400~1,600 ppm, 30~40 ppm, 220~250 ppm, and 260~300 ppm, respectively, of which acetate was over 70%. The biodegradabilities of aerobic and anaerobic acidogenesis were 30% and 25%, respectively. Methanogensis could be activated under 1 % of NaCl and 1,000 ppm of volatile fatty acids at the range of pH 6.8~7.2. The maximum mixture ratio of food waste and sewage sludge in the present study was 2:8 by the result of VS removal rate and Methane production.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.1
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• pp.121-125
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• 2006

To study the effects of plasticizer concentration and its ratio on the physical properties of silk fibroin films, polyethylene glycol (PEG) was used at 4 different concentrations; 1, 2, 3, $4.5\%$ (w/v). Tensile strength (TS) and water vapor permeability (WVP) increased with the increase of PEG concentration, while opposite trend was observed for percent elongation of silk fibroin films. WVP of silk fibroin films increased from $2.54\;ng{\cdot}m/m^2spa$ for $1\%$ of PEG to $5.41\;ng{\cdot}m/m^2sPa$ for $4.5\%$. In addition, a mixture of PEG and glycerol (Gly) as a plasticizer was used at the ratio of 100:0, 75:25, 50:50, 25:75, and 0:100 (w/w). Percent elongation of the films was improved to $130.95\%$ when the ratio of 75:25 was used. On the contrary, WVP of silk fibroin films increased with the decrease of the ratio of PEG:Gly. Effect of the plasticizer concentration and its ratio on the color of silk fibroin films was negligible. These results suggest that mixture of PEG and Gly as a plasticizer provide more flexible than PEG alone in silk fibroin films, and the best ratio of PEG to Gly was 75:25.

• KSBB Journal
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• v.18 no.4
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• pp.318-323
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• 2003

This study was carried out to investigate the possibility of reusing newspaper or paperbox waste by methane fermentation. When 15 g of newspaper and box wastes were digested separately for 24 days by batch fermentation, the amount of total organic acids produced were 2461 and 4978 mg/L, respectively. The tCOD removal rates were found to be 60.9 and 62.4%, respectively. In addition, the removal efficiencies of total solid were 34.8 and 33.4%, and those of volatile solid were 40.0 and 39.2%, respectively. During this period, the amounts of biogas produced were 6.95 and 6.43 L. In a semicontinuous reaction, tCOD removal efficiencies for newspaper and box wastes were 64.7 and 65.0%, respectively, after 14 days of digestion. After 25 days, which were needed to stabilize the methane fermentation, the amounts of biogas produced daily were 0.31 and 0.30 L/g.dry wt, respectively. Methane contents were 57.3 and 56.2%, respectively, and the pHs in the anaerobic acidogenic and methanogenic fermenters were 5.0 and 7.5, respectively.