• Journal of Korean Society of Environmental Engineers
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• v.27 no.2
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• pp.123-129
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• 2005

In situ permeable reactive barrier (PRB) technologies have been proposed to reductively remove organic contaminants from the subsurface environment. The major reactive material, zero valent iron ($Fe^0$), is oxidized to ferrous iron or ferric iron in the barriers, resulting in the decreased reactivity. Iron-reducing bacteria can reduce ferric iron to ferrous iron and iron reduced by these bacteria can be applied to dechlorinate chlorinated organic contaminants. Iron reduction by iron reducing bacteria, Shewanella algae BrY, was observed both in aqueous and solid phase and the enhancement of TCE removal by reduced iron was examined in this study. S. algae BrY preferentially reduced Fe(III) in ferric citrate medium and secondly used Fe(III) on the surface of iron oxides as an electron acceptor. Reduced iron formed reactive materials such as green rust ferrihydrite, and biochemical precipitation. These reactive materials formed by the bacteria can enhance TCE removal rate and removal capacity of the reactive barrier in the field.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.817-820
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• 2008

The river environments of many streams in korea have been deteriorate through the rapid industrialization and urbanization since the 1960s. In korea, on the other hand, much efforts on the research and project have been made for the restoration of the deteriorated streams to close-to-nature. in order to restore the deteriorated streams, therefore, it is necessary to investigate such advanced technologies and materials. In view of this requirement, various research paths are being taken focusing on coarse aggregates to make multi-functional porous concrete having continuous voids so as to improve water and air permeability, acoustic absorption, water purification and applicability to vegetation. The Purpose of this study is to investigate the method for recovery of the environment in the streams area using porous concrete retaining wall block. the multi-P.O.C block applies for test in the Jangduri-cheon have been monitored planting, stability etc. after 6 months, plant grows flourishing and reconstructed in state such as nature rivers.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.36 no.1
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• pp.71-77
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• 2010

The water fern Azolla belongs to the Azollaceae and forms a symbiotic association with a $N_2$-fixing cyanobacterium, referred to as Anabaena azollae, and this association has currently been demonstrated to have potential as a nitrogen source for rice production. Because of that, Azolla fern has been used not only as organic manure in southern China and northern Vietnam for a long time but also as food for animate creatures in the underwater and decontaminant in the water. However, the phenolic compounds and active materials of Azolla have not been examined in detail in the past studies. In the present study, anti-oxidant ability test and experiment to find a particular active material of Azolla imbricata and Azolla imbricata fraction (AIF) were performed. In anti-oxidant test such as DPPH test and lipoxygenase inhibition test, the value of test represented high activities compared with authentic sample - green tea and NDGA (nordihydroguaiaretic acid). In MMP-1 test, related to collagen protection and elasticity of skin, its inhibitory effect was measured over 75 %, and the phenolic compounds of AIF related with this activity were confirmed luteolin derivatives by using FT-IR spectroscopy, element analyzer (EA) and Liquid chromatography-MASS spectroscopy.

• Journal of Soil and Groundwater Environment
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• v.13 no.3
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• pp.8-14
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• 2008

The effects of surfactant types and the ratio of nonionic and anionic surfactants on the washing of diesel contaminated soil were investigated. In batch tests, the nonionic surfactant, which has HLB within 12-13, showed a high diesel removal efficiency and Tergitol 15-S-7 (T15S7) with 20 g/L concentration exhibited the highest removal efficiency of 79-88% among the tested nonionic surfactants. Anionic surfactants, in general, showed lower removal efficiency than nonionic surfactants. In case of mixed surfactant system, the removal efficiency increased with nonionic surfactant concentration. With mixed surfactants of T15S7 and SDS as 3 : 1 ratio, diesel removal was enhanced to 76% with 10 g/L of the mixed surfactants. These results could be used in the selection of proper surfactants for remediation of diesel contaminated soils.

• Composites Research
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• v.35 no.2
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• pp.115-119
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• 2022

The performance of carbon fiber is important for the production of these high-quality polymer composite materials such as CFRP (Carbon Fiber Reinforced Plastic). For this purpose, it is essential to use an optimized spinning process for improving the mechanical, physical, and structural properties of the precursor fiber, which greatly affects the properties of the carbon fiber, and the use of a suitable precursor polymer. In this study, the content of MAA (Methacrylic Acid), MAA injection time, and concentration of AIBN (2,2'-Azobis(2-methylpropionitrile)) were set as parameters for the polymer synthesis process, and Poly(AN-co-MAA) (poly(acrylonitrile-co-methacrylic acid)) was polymerized by solution polymerization. Poly(AN-co-MAA) with a molecular weight of 305,138 g/mol and an MAA ratio of 4.2% was dissolved in DMF (N,N-dimethylformamide) at a concentration of 16.0 wt%, and then a precursor fiber was prepared through dry-jet-wet spinning. The precursor fiber had a tensile strength of ~1.06 GPa and a tensile modulus of ~22.01 GPa, and no voids and structural defects were observed on the fiber.

• Journal of Life Science
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• v.32 no.9
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• pp.721-728
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• 2022

This study investigated the diversity of intestinal microbial communities isolated from the intestine of topshell (Turbo cornutus) from the coast of Jeju Island (Beobhwan, Seogwipo city). Pure cultivation using the standard marine agar (MA) medium showed the most significant number of clusters. Aerobic and anaerobic culture allowed isolation of strains of 1.8×10⁵ CFU·g^-1 and 0.4×10 CFU·g^-1 on average, respectively. The microbial population in the topshell intestine was classified into 4 phyla, 12 families, 26 genera, and 67 species. The microbes in the topshell intestine were detected by homology with 93~100% with standard strains. The microbes in the topshell intestine consisted of Proteobacteria 39%, Firmicutes 34%, Actinobacteria 21%, and Bacteroidets 6%. The identified families were Alteromonadaceae (1), Shewanellaceae (4), Vibrionaceae (12), Phyllobacteriaeceae (1), Rhodobacteraceae (8), Bacillaceae (21), Paenibacillaceae (2), Cellulomonadaceae (1), Mycobacteriaceae (6), Nocardiaceae (4), Streptomycetaceae (3) and Flavobacteriaceae (4). Bacillus sp. and Vibrio sp. accounted for the greatest portion of the separated strains. Among the isolated microorganisms, some strains had probiotic functions.

• Clean Technology
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• v.29 no.4
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• pp.272-278
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• 2023

There is a lot of interest in methods for pollutants using adsorption, and recent research is being conducted to show that biochar can be used to remove organic and inorganic pollutants. In particular, wood waste as waste biomass requires a biomass recycling method, and a method to increase the adsorption capacity of biochar produced using wood waste is needed. Biochar is created by Hydrothermal carbonization (HTC) using, which uses low temperature and high pressure, has low energy consumption and does not require moisture removal pretreatment, and biochar is created through chemical activation using KOH, NaOH, and ZnCl₂ chemicals. The adsorption characteristics of biochar were determined by analyzing iodine adsorptivity, specific surface area, pore diameter, pore volume, pore distribution, and SEM according to the activation. The results of analyzing the selecting biochar by activating the biochar produced at HTC 300℃, 4 hr by KOH, NaOH, and ZnCl₂ chemicals, the specific surface area was 774~1.387 m²/g, showing a high specific surface area similar to activated carbon, and it was confirmed that micropores with an average pore diameter in the range of 21~24 Å were formed. As a result of SEM observation, the surface was uniform with a certain shape depending on activation. It was confirmed that one pore was developed and the number of pores increased.

• Journal of Soil and Groundwater Environment
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• v.11 no.1
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• pp.14-22
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• 2006

Laboratory column experiment for simultaneous removal of Cd and Cr(VI) were conducted using newly developed material of Fe-loaded zeolite having both reduction ability and sorption capacity. The solution containing Cd and Cr(VI) was injected into the column and the breakthrough curves (BTCs) for the contaminants were observed at the effluent port. Cd breakthrough was not initialized until Cr(VI) breakthrough was completed. Therefore it could be concluded that overall efficiency of Fe-loaded zeolite should be determined by the reactivity for Cr(VI). The relative concentration of Cr(VI) BTC increased to the unit value while initial breakthrough was delayed and the propagation of breakthrough was slowed. In order to quantitatively describe the shape of Cr(VI) BTC, new parameters of ${\alpha}\;and\;{\beta}$ designated to be shape parameters, were defined and applied in contaminant transport concentration. These parameters were employed to represent the degree of initial breakthrough delay and the degree of breakthrough propagation, respectively. As initial contaminant concentration increased, ${\alpha}$ decreased, which indicated the delay of BTC's initiation. And as initial contaminant flow rate increased, ${\beta}$ decreased, which represented the faster propagation of the BTC. From these results, Fe-loaded zeolite was found to be an effective reactive material for PRBs against heavy metals having different ionic forms in groundwater. And it could be expected that as groundwater flows faster, the propagation of breakthrough would be faster and as contaminant concentration is higher, the initial point of breakthrough would appear earlier.

• Korean Journal of Medicinal Crop Science
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• v.13 no.4
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• pp.154-160
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• 2005

This study was performed to compare anticancer and immune activities between natural Artemisia capillaris Thunb. extract and tissue cultured plant extract (hairy root, in vitro culture, callus). The inhibitory effect of cancer cell growth, human B cell growth and productivity of cytokines were examined. Furthermore, HPLC analysis was performed to confirm the components. The anticancer activities increased by more than 55% with the cultured callus of Artemisia capillaris T. for four cancer cell lines(Lung carcunoma, Stomach adenocarcinoma, Hepatocillular carcinoma, Breast adenocarcinoma), showing higher effect than natural Artemisia capillaris T. The extracts from hairy root and in vitro culture of Artemisia capillaris T. significantly increased the immune B cell growth. The immune B cell growth effect of natural Artemisia capillaris T. was higher than that of the tissue culture plants such as hairy root, in vitro culture and callus. Both natural and tissue cultured plants showed similar effects on cytokine secretion. The similar peak size was observed between natural Artemisia capillaris T. and cultured callus in HPLC analysis. As a results, the biological activities were not observed the difference between natural Artemisia capillaris T. and cultured callus. Thus, the cultured callus will be altered natural Artemisia capillaris T. in the environmental side and the resources preservative side

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.10
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• pp.1258-1263
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• 2008

The current study examined the effects of radish leaves powder on the excretion of fecal triglyceride, and sterol and hepatic UDP-glucuronyl transferase (UDPGT) activity in rats fed hypercholesterolemic diet. Male Sprague-Dawley rats weighing 100$\pm$10 g were randomly assigned to normal control group (N group), normal diet with 5% radish leaves powder supplemented group (NR) and hypercholesterolemic groups, which were sub-divided into radish leaves powder free diet group (HC) and 2.5% (HRL), 5% (HRM), and 10% (HRH) radish leaves powder supplemented groups. The experimental diets were fed ad libitum for 4 weeks. Fecal weights and water contents were significantly increased in all radish leaves powder supplemented groups (NR, HRL, HRM, and HRH) than that of N and HC groups. Fecal total lipid contents including fecal neutral and acidic sterols in radish leaves powder supplemented groups were higher than those of the HC group, and especially that of HRH group was the highest among all experimental groups. Hepatic UDPGT activity of HRH group was 38% higher than that of HC group. Excretions of fecal bile acid were increased 2.3 and 2.7 folds in HRM and HRH groups compared with that of HC group. And neutral sterol, coprostanol, and coprostanone contents of them were higher in radish leaves supplemented groups than in HC group. These results suggest that radish leaves may act as potential substitute for a dietary fiber capable of improving a gastrointestinal function and lipid metabolism.