• International Journal of Highway Engineering
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• v.17 no.6
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• pp.19-26
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• 2015

PURPOSES : This study intends to develop an inorganic soil pavement material using industrial by-products and to evaluate its applicability as a road pavement material. METHODS : In this study, a compressive strength experiment was conducted based on the NaOH solution molarity and water glass content to understand the strength properties of the soil pavement material according to the mixing ratio of alkali activator. In addition, the strength characteristic of the inorganic soil pavement material was analyzed based on the binder content. The performance of the soil pavement was evaluated by conducing an accelerated pavement test and a falling weight deflectometer (FWD) test. RESULTS : As a result of the soil pavement material test based on the mixture ratio of alkali activator, it was identified that the activator that mixed a 10 M NaOH solution to water glass in a 5:5 ratio is appropriate. As a result of the inorganic soil pavement materials test based on the binder content, the strength development increased sharply when the amount of added binder was over 300 kg; this level of binder content satisfied 28 days of 18 MPa of compression strength, which is the standard for existing soil pavement design. According to the measured results of the FWD test, the dynamic k-value did not show a significant difference before or after the accelerated pavement testing. Furthermore, the effective modulus decreased by approximately 50%, compared with the initial effective modulus for pedestrian pavement. CONCLUSIONS : Based on these results, inorganic soil pavement can be applied by changing the mixture proportions according to the use of the pavement, and can be utilized as road pavement from light load roads to access roads.

• Polymer(Korea)
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• v.31 no.6
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• pp.491-496
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• 2007

In the polymeric dental restorative composites, the resin matrix mainly contains 70 wt% 2,2-bis[4-(2-hydroxy-3-methacryloyloxy propoxy) phenyl] propane (Bis-GMA), as a base resin and 30 wt% triethylene glycol dimethacrylate (TEGDMA) as a diluent. Even though the viscosity of the resin matrix is rapidly decreased by adding TEGDMA, addition of TEGDMA to the Bis-GMA results in reduction in the mechanical properties and increase in the curing shrinkage of the dental composite. In order to fabricate dental composite exhibiting excellent properties by reducing TEGDMA content in the resin matrix, in this study, Bis-GMA derivatives, which do not contain hydroxyl groups, were used instead of Bis-GMA. The curing characteristics of Bis-GMA derivatives were similar with those of Bis-GMA, while the former exhibited lower viscosity and water absorption than the latter. Comparing the curing shrinkage of the dental composite containing Bis-GMA derivative with that prepared from Bis-GMA, the reduction in curing shrinkage was about 25%. Dental composites prepared from new resin matrices also exhibited low water uptake and better properties in mechanical strength.

• Journal of Korean Society on Water Environment
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• v.23 no.5
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• pp.723-730
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• 2007

This study was conducted to develop a combined method for remediating a Chlorinated Aliphatic Hydrocarbons (CAHs) mixtures-contaminated aquifer. The process is consist of two processes. A chemical process (1st) using natural zinc ores for reducing higher concentrations of CAH mixtures to the level at which biological process is feasible; and A biological process (2nd) using aerobic cometabolism for treating lower concentration of CAH mixtures (less than 1 mg/L). Natural zinc ore showed relatively high transformation capacity, average dehalogenation percentage, and the best economic efficiency in previously our study. To evaluate the feasibility of the process, we operated two columns in series (that is, chemical and biological columns). In the first column filled with natural zinc ore and sand, CAH mixtures were effectively transformed with more than 95% efficiency, the efficiency depends on the Empty Bed Contact Time (EBCT) and the mass of zinc ore packed. Scanning Electron Microscope (SEM), X-Ray Diffraction (XRD) analysis were performed to make sure whether natural zinc ore played an key role in the dechlorination of the CAH mixtures. The characteristics of zinc metal surface changed after exposure to CAHs due to oxidation of $Zn^0$ to $Zn^{2+}$. In the biological column injecting propane, DO and effluent of the chemical column, only 1,1,1-TCA was cometabolically transformed. Consequently, the combined process would be effective to remediate an aquifer contaminated with high concentrations of CAH mixtures.

• Korean Journal of Veterinary Research
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• v.57 no.3
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• pp.147-154
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• 2017

The present study was performed to evaluate the hangover relieving effect of germinated buckwheat (GB) and Sanghwang mushroom mycelium cultured in GB (SGB). Both GB and SGB showed 1,1-diphenyl-2-picrylhydrazyl radical scavenging activities and significantly increased (p < 0.001) aldehyde dehydrogenase (ALDH) activities; up to 140% increase at concentrations of $16{\mu}L/mL$. Locomotor activity test results from alcohol-SGB and alcohol-GB groups showed improved motor activities over that of the alcohol-water group at 90 min post-administration. Both alcohol-GB and alcohol-SGB groups had significantly reduced (p < 0.001) alcohol ($40.02{\pm}33.38{\mu}g/mL$, $66.01{\pm}22.04{\mu}g/mL$, respectively) and aldehyde ($5.72{\pm}0.47{\mu}g/mL$, $6.72{\pm}1.70{\mu}g/mL$, respectively) concentrations in blood compared to those in the alcohol-water group ($199.75{\pm}33.83{\mu}g/mL$, $50.43{\pm}13.88{\mu}g/mL$, respectively) at 90 min post-administration. Based on cDNA microarray analysis, expressions of ALDH genes ALDH1a7 and ALDH18a1 and cytochrome P450 (CY450) gene CYP4a30b were upregulated in the alcohol-GB and alcohol-SGB groups compared to levels in the control group. Overall, the results suggest that both GB and SGB have hangover relieving effects by reducing blood acetaldehyde levels. The molecular mechanisms may involve ALDH activation and upregulated expression of alcohol metabolism-related genes such as ALDH and CYP450.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.1
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• pp.55-68
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• 2012

Impervious surface increase due to urbanization, one of the leading causes of pavement increased the runoff coefficient, peak flow, and reducing the infiltration flow and thereby causing flooding and river erosion is occurring in aquatic ecosystems are known to impair. This study aimed to classify use type of detailed land into the road, reststop, tollgates and etc. focused on major domestic highways, to understand the characteristics of rainfall runoff pollutants and to calculate applicable unit pollution load. Because of high runoff coefficient and short travel time to drainage. first flush occurred clearly. Average EMCs of runoff in the highway was investigated as TSS 108.47 mg / L, COD 28.16 mg / L, BOD 13.61 mg / L, TN 6.38 mg / L, TP 0.03 mg / L, Cu 118.17 ${\mu}g$ / L, Pb 345.3 ${\mu}g$ / L, Zn 349.47 ${\mu}g$ / L. Unit pollution loads calculated by detailed land use area of highways based on average annual rainfall, EMCs, applicable basin areas and etc. were 46.6 kg/km2/day of BOD, 1.4 kg/km2/day of TP, 8.81 kg / km2/day of TN and these were BOD 50.8%, TP 66.7%, TN 64.4%in comparison of the unit pollution loads which applies fallow land standards of the TMDL(Total Maximum Daily Load). It was considered that discharged loads can be excessively calculated in case highway non-point management plans based on unit pollution load of the current land standard.

• Korean Journal of Medicinal Crop Science
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• v.25 no.1
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• pp.29-36
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• 2017

Background: Ganoderma lucidum cultured on hulled barley was investigated as a potential natural source of antioxidants and anti-inflammatory agents. Methods and Results: The yields from Ganoderma lucidum cultured on hulled barley water and ethanol extract were 17.69% and 25.77%, respectively. The antioxidant activity of Ganoderma lucidum cultured on hulled barley extracts was confirmed by various methods including assayss of 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azino-bis-(3-ethylbenzo thiazoline-6-sulfonic acid) (ABTS), nitrite radical scavenging, and $Fe^{3+}$ to $Fe^{2+}$ reducing power activity. The ethanol extract of Ganoderma lucidum cultured on hulled barley showed improved DPPH, ABTS and nitrite radical scavenging activity compared with the water extract. After treatment of RAW264.7 cells with Ganoderma lucidum cultured on hulled barley ethanol extracts, the cell viability compared with the control was 92.82%, even at a concentration of $3,000{\mu}g/m{\ell}$. The ethanol extract inhibited reactive oxygen species (ROS) generation in RAW264.7 cells stimulated with $H_2O_2$, even at low concentrations. In addition, the ethanol extract showed an inhibitory effects on the production of lipopolysaccharide-induced nitric oxide (NO) in RAW264.7 cells. Conclusions: This study suggests that the extract of Ganoderma lucidum cultured on hulled barley is a potential source of natural antioxidants and anti-inflammatory agents.

• Journal of the Korean Chemical Society
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• v.62 no.1
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• pp.30-35
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• 2018

The purpose of this study was to decrease the protein adsorption and improve the function of the hydrophobic acrylic Intraocular lens(IOL). Hydrophobic acrylic intraocular lenses were prepared by using ethyleneglycol phenyletheracrylate (EGPEA), styrene and 2-hydroxyethyl methacrylate (HEMA). Polyvinyl pyrrolidone (PVP) and 2-methacryloyloxyethyl phosphorylcholine (MPC) were used as additives. Water contents, wettability, light transmittance and protein adsorption amount were measured to evaluate the physical properties of the intraocular lens. The water content and wettability of all samples containing additives were increased and the amount of protein adsorption decreased. In particular, samples containing MPC showed a further decrease in protein adsorption. The hydrophobic acrylic intraocular lens with PVP and MPC was found to improve the function of the intraocular lens by reducing the protein adsorption while having basic physical properties.

• Journal of Environmental Health Sciences
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• v.19 no.2
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• pp.46-54
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• 1993

This study was carried out on the stabilized/solidified treatment for the reducing leachability of hazardous heavy metals copper, lead, chromium and cadmium in the hazardous sludge which treated to be unleached heavy metals by sodium diethyl dithiocarbamate. Cement matrix was analyzed for the leachability of 24 hrs and dynamic leaching test, structure and the optimum condition for the stabilization and solidification of the hazardous sludge. In 28 days of curing time the unconfined compressive strength was 21.5 kg/cm$^2$ at the ratio of portland cement (0.5)+fly ash (0.25) and 23.5 kg/cmz at the ratio of portland cement (0.5)+fly ash (0.25) + cake (0.25). High concentration of Pb, Cr and Cd in the sea water and Cu in the distilled water were leached at the dynamic leaching test. The concentration of leaching heavy metals for specimens which were tested 24 hrs were found low leachability with decreasing pH of leachant. According to dynamic leaching test, the low level of copper, lead, cadmium and chromium were leached in the cement matrix with sodium diethyl dithiocarbamate. But the effective diffusion coefficient of unleached cement matrix which was treated sodium diethyl dithiocarbamate was decreased above 2 times than that of cement matrix. The relation of leachant renewal period (Y) and cumulative fraction ion leached (X) was the following regression equations. Solidification with unleached agent. Y$_{Cu}$ = 1413752X + 247, Y$_{Pb}$ = 223501IX + 214, Y$_{Cr}$ = 8310601X - 472, Y$_{Cd}$ = 168787X + 1061 The structure of' solidified matrix with X-ray diffraction analysis was composed more Ca(OH)$_2$, Si, Mg(OH)$_2$ and Al in the unleached cement matrix than those in cement matrix.

• Journal of Environmental Science International
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• v.16 no.12
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• pp.1369-1382
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• 2007

To find proper water quality management strategy for oxygen consumption organic matters in Jinhae bay, the physical process and net supply/decomposition in terms of COD was estimated by three-dimensional eco-hydrodynamic modeling. The estimation results of physical process in terms of COD showed that transportation of COD was dominant in loading area from land to sea, while accumulation of COD was dominant in $middle{\sim}bottom$ level. In case of surface level, the net supply rate of COD was $0{\sim}60\;mg/m^2/day$. The net decomposition rate of COD was $0{\sim}-0.05\;mg/m^2/day$($-5{\sim}-10$ m, in depth) to 2 level, and $-0.05{\sim}-0.20\;mg/m^2/day(10m{\sim})$ to bottom level. These results indicate that the biological decomposition and physical accumulation of COD are occurred for the most part of Jinhae Bay bottom. The variation of net supply or net decomposition rate of COD as reducing land based input loading is also remarkable. Therefore, it is important to consider both allochthonous and autochthonous oxygen demanding organic matters to improve the water quality of Jinhae Bay.

• Journal of the Korea Concrete Institute
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• v.18 no.5 s.95
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• pp.703-708
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• 2006

The slurry infiltrated fiber concrete(SIFCON) is recognized as one of the most promising new construction materials. Compressive and direct tensile tests are performed to investigate the mechanical property of SIFCON. Hooked-end steel fibers are used in the mix with fiber volume fraction varied from 4% to 10%. The water/cement ratio is kept constant at 0.4. The amount of silica fume added is 10% by weight of cement and 0.5% of water reducing agent is added to improve the workability of the slurry. The test results in this study show that the compressive strength of SIFCON is about 1.59 to 2.68 times in comparison with the cement paste. Tensile strength is showed the enhancement of about 2.51 to 8.77 times. It is also observed that the toughness and ductility of SIFCON are increased significantly with the increasing in fiber volume fraction.