• Journal of Korean Society on Water Environment
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• v.22 no.1
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• pp.51-58
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• 2006

The effluent limitations for individual industry based on the best available technology economically achievable (BAT) have been required to achieve effective regulation. BAT assessment criteria that are suitable for the circumstances of Korean industry were developed in the previous study. The criteria were applied to determine the BAT for leather tanning and finishing industry. For the evaluation BAT, a subcategorization for the industry considering wastewater characteristics, source equipments, raw material and so on should be suggested. Three subcategories: A) Unharing, Chrome Tan, Retan-Wet Finish, B) Chrome Tan, Retan-Wet Finish, and C) Furskins were proposed in this study. Wastewater discharged from the each category contains high concentration of COD, chrome, nitrogen and sulfide. In particular, the concentration of nitrogen from the subcategory A is significantly greater. Twenty sites were surveyed and wastewater qualities were analyzed. Therefore, six different technologies were applied to the subcategory A for the end-of-pipe treatment technology, and a technology was used in the subcategory B and C, respectively. The technology candidates were evaluated in terms of environmental impacts, economically achievability, treatment performance and economical reasonability. As the result, the technology options for each subcategories: A) primary chemical precipitation + modified Ludzack-Ettinger process (MLE) + secondary chemical precipitation, B) chemical precipitation + typical activated-sludge process + Fenton oxidation, C) chemical precipitation + typical activated-sludge process + batch Fenton oxidation or batch activated carbon treatment were selected as the BAT, respectively.

• Korean Journal of Agricultural Science
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• v.45 no.4
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• pp.741-748
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• 2018

This study was conducted to evaluate the nutritional value of total mixed rations (TMR) containing rice grain in an in vitro rumen fermentation system. Three types of grains (corn, wheat, and rice), timothy, and soybean meal (SBM) were used to prepare the experimental TMR: Corn TMR, Wheat TMR, and Rice TMR. The rumen fermentation characteristics of all the experimental TMRs were evaluated by an in vitro anaerobic system using rumen fluid for 24 and 48 h. The digestibility of the nutrients (dry matter [DM], crude protein [CP], and neutral detergent fiber [NDF]), pH, ammonia ($NH_3-N$), and volatile fatty acids (VFA) were determined. Rice TMR showed a higher DM digestibility than that of the Corn TMR at 48 h (p < 0.05). In all treatments, the CP digestibility was more than 80% at 48 h, but no significant differences were observed among the treatments. The NDF digestibility tended to be the lowest in the Wheat TMR (p = 0.06), and the pH tended to be the lowest in the Rice TMR (p = 0.09) among the treatments for the 48 h incubation. The Wheat TMR had the highest $NH_3-N$ concentration among the treatments (p < 0.01). Rice TMR had a lowest total VFA concentration among the treatments (p = 0.05) at 24 h, but no significant differences were observed at 48 h. Based on this in vitro result, it was considered that a rice grain has the potential to replace conventional grain ingredients when the TMR was formulated.

• Journal of Animal Science and Technology
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• v.65 no.2
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• pp.351-364
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• 2023

The experiment was carried out to study the effect of Korean wild ginseng adventitious root supplementation on the laying performance, egg quality, cytokine expression, ginsenoside concentration, and microflora quantity of Institut de selection Animale (ISA) brown laying hens at 24 weeks old. A total of 90 laying hens were subjected to a completely randomized design at three treatments, five repetitions and six laying hens per replicate. The experiments were divided by diets into the basic feed (CON), basic feed + 0.1% wild ginseng (WG1), and basic feed + 0.5% wild ginseng (WG2). The feeding trial was carried out over a duration of 12 weeks after an initial acclimation period of 2 weeks. Feeds and water were administered ad libitum in mash form, and light was available for 16 hours per day. At the end of study, henday egg production (HDEP), average egg weight (AEW), and egg mass (EM) were increased (p <0.05) in WG2 at week 12. Feed conversion ratio (FCR) was decreased (p < 0.05) in WG2 at week 12. The ginsenoside content in egg yolk was increased (p <0.05) in laying hens in the WG2 treatment at week 12. Relative expression of tumor necrosis factor alpha (TNF-α) was reduced (p < 0.05) in the WG supplemented diets at week 12. The fecal microflora quantity of Lactobacillus was increased (p < 0.05) in WG2 at week 8 to week 12, and Escherichia coli (E. coli) was significantly decreased (p < 0.05) in the WG2 at week 12. We concluded that the result observed in the HDEP, AEW, EM and FCR was due to an increase in ginsenoside content, leading to an improvement in the TNF-α, and fecal microflora quantity such as Lactobacillus and E. coli in the WG2 supplemented diets. We therefore recommend the use of WG at application level 0.5% per basal diet for optimum laying performance in layer hens.

• Journal of the Korea Safety Management & Science
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• v.25 no.1
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• pp.7-14
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• 2023

We attempted to provide an overview of the laws and current state of the 3D printing industry in South Korea and around the world, using the annual industry surveys and the Wohler report. Additionally, we reviewed articles relating to the potential exposure to hazards associated with 3D printing using metal materials. In South Korea, there were 406 3D printing-related businesses, employing 2,365 workers, and the market size was estimated at 455.9 billion won in 2021. Globally, the average growth rate of the 3D printing industry market over the past 10 years was 27.4%, and the market size was estimated at $11.8 billion in 2019. The United States had the highest cumulative installation ratio of industrial 3D printers, followed by China, Japan, Germany, and South Korea. A total of 6,168 patents related to 3D printing were registered in the US between 2010 and 2019. Harmful factors during metal 3D printing was mainly evaluated in the powder bed fusion and direct energy deposition printing types, and there is a case of material extrusion type with metal additive filaments. The number, mass, size distribution, and chemical composition of particles were mainly evaluated. Particle concentration increases during the opening of the chamber or post-processing. However, operating the 3D printer in a ventilated chamber can reduce particle concentration to the background level. In order to have a safe and healthy environment for 3D printing, it is necessary to accumulate and apply knowledge through various studies.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.5
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• pp.596-605
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• 2023

Sik-hae is a traditional Korean salt-fermented seafood having a low salt content and a high concentration of Lactobacillus, unlike most salt-fermented fish and fish sauce, which have a high salt content and low concentration of Lactobacillus. This study aimed to investigate the health-promoting functional properties of 10 types of commercial sik-haes. The results showed that for the commercial sik-haes studied, angiotensin-I-converting enzyme inhibitory activity, DPPH radical scavenging activity, α-glucosidase inhibitory activity, xanthine oxidase inhibitory activity, and sodium nitrite scavenging activity ranged from 29.0% to 46.3%, 35.5% to 65.4%, 0% to 20.0%, 20.1% to 78.8% , and 17.9% to 82.6%, respectively. Antimicrobial activity against Escherichia coli, Vibrio parahaemolyticus and Staphylococcus aureus was rarely detected. The results on healthy functional properties suggest that the commercial sik-haes are expected on the antioxidative activity in F-1-F-5, AP-1, BES, and S, xanthine oxidase inhibitory activity in the other 9 types expected for A, and sodium nitrite scavenging activity in the other 9 types expected for AP-2.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.909-910
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• 2007

The volatile organic compounds exposure is governed by the source distance and dispersion of the pollutant into air and groundwater. The purpose of this study was to validate suggested models for the prediction of concentration distributions. The study design was organized into different methods to simulate industry site. The distribution models generally showed a fair agreement with measured data. For graphical representation of concentration of volatile hydrocarbon, it has to obtain a continuous representation of the contamination of the site. Therefore, the used interpolative methods examined for this project are the IDW(inverse Distance Weighting) and kriging method. In the results, in summary, all two different methods can be used to quantify exposures at a particular source area, and thus provide, a solid foundation for making risk-based decisions. All the calculations can be performed using Excel's built-in functions, and the capabilities of geospatial analysis allow the results to be displayed visually. However, anyone who uses these methods should understand all of the assumptions and limitation.

• Journal of the Korean Ceramic Society
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• v.42 no.11 s.282
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• pp.743-748
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• 2005

The effect of reaction parameters in the characteristic of $Pb(Zr_{0.52} Ti_{0.48})O_3$ powders by hydrothermal process was investigated in this study. In the preparation of PZT, the types of starting material and concentration of mineralizer on phase fraction and morphology was investigated respectively. Regardless the types of Pb precursor, PZT was able to synthesize ranging from 7 to 20 on KOH concentration and from 13.01 to 13.55 on pH of solution. The particle size of the PZT powders can be controlled by the mineralizer concentration and various types of precursor.

• Journal of Microbiology and Biotechnology
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• v.12 no.4
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• pp.617-621
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• 2002

In order to optimize the carrot hairy root culture for SOD production, a fed-batch culture of hairy roots was performed in a bioreactor. Maximum SOD activity was obtained when the hairy roots were transferred to the MS medium containing 110 g/1 concentration of sucrose. By controlling the sucrose concentration (70 g/1 sucrose for growth and 110 g/1 sucrose far production, respectively) In a two-stage fed-batch culture, 29 g/1 of the hairy roots was obtained based on the final dry mass. The volumetrically determined SOD activity and productivity in the fed-batch culture were about 6 times higher than those from the flask culture containing sucrose at 30 g/1 concentration.

• Nutritional Sciences
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• v.6 no.3
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• pp.141-147
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• 2003

Fruits and vegetables reportedly have a protective effect against hyperlipidemia and oxidative disease. Accordingly, this study aimed to investigate the lipid-lowering effect and antioxidative capacity of persimmon leaf extract (PLE) in rats fed a high-cholesterol diet. Male rats were fed a high-cholesterol (1% wt/wt) or high-cholesterol diet supplemented with Lovastatin (0.02% wt/wt) or PLE (0.2% wt/wt) for 5 weeks. The concentration of plasma total cholesterol was significantly lower in the PLE group than in the lovastatin group. However, the concentration of plasma HDL-cholesterol and the ratio of HDL-cholesterol/total-cholesterol (%) were significantly higher in the PLE group than in the control group. The PLE supplement also significantly lowered the contents of hepatic cholesterol and triglyceride. In comparing fecal sterol contents, the PLE group saw a significant increase of both neutral and acidic sterol compared to the other groups. The PLE supplement significantly lowered plasma GOT and GPT activity, which ave indices of hepatic toxicity. Plasma TBARS concentration was significantly lower in the PLE group than in the control group, while hepatic TBARS level was not significantly different between the groups. In a comparison of hepatic antioxidant parameters, SOD, catalase and GSH-Px activity were significantly higher in the PLE group than in the control group. However, the PLE supplement significantly towered antioxidant enzyme activity in the erythrocyte. Furthermore, these results suggest that supplementation of PLE promoted the excretion of fecal sterols, thereby leading to decreased absorption of dietary cholesterol. In addition, PLE may play an important role in regulating antioxidative capacities by altering SOD and ChT activity.

• The Korea Journal of Herbology
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• v.22 no.3
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• pp.85-91
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• 2007

Objective : In this study, anti-oxidant and cosmeceutical activities of Isatis tinctoria L. extracted from water, ethanol and supercritical fluid condition were confirmed to investigate cosmeceutical activities for utilization as cosmetic ingredient. Methods: Anti-oxidant and cosmeceutical activities were investigated by using electron donating ability, xanthine oxidase, tyrosinase, astringent effect. Result : Isatis tinctoria L. extracts by supercritical fluid, water and ethanol showed good electron donating ability which were 82.7%, 62.6% and 44.8% at the concentration at 1,000ppm, respectively. Xanthine oxidase activity related with purine metabolism was inhibited by ethanol extract about 52.3% at the concentration at 1,000ppm. Tyrosinase inhibition effects, by supercritical fluid extract, ethanol extract and water extract, were 83.3%, 52.9% and 41.2% respectively at 1,000ppm. In the measurement of astringent effect, supercritical fluid extract at the concentration to 5,000ppm showed 85.7% in related activity. The water extract showed 95.9% nitrite scavenging activity at 5,000ppm. Conclusion : According to these results, it is possible that the extract of Isatis tinctoria L. can be used as a new natural material of cosmetic industry.