• Journal of the Korean Society of Groundwater Environment
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• v.2 no.2
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• pp.85-92
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• 1995

This study was conducted to find out the relationship between microflora in groundwater and its physico-chemical environmental factors at the 59 sites, where distributed at 3 cities and 18 counties in Jeonranam-Do, Korea. The average values of environmental factors were as followings; pH 6.9, temperature 20.1 $^{\circ}C$, dissolved oxygen 6.5 mg/1, the depth of wells 80.1 m, and nitrate 10.7 mg/1. The average value of microbial population size; Heterotrophic bacteria-NA (HPC-NA) and heterotrophic bacteria-YEPD (HPC-YEPD) were 1.4${\times}$10$^3$CFU/ml and 0.59${\times}$10$^3$ CFU/ml respectively HPC-YEPD numbers were 42.1% of HPC-YEPD. Coliform bacteria were detected at 16 sites, and its average numbers were 6.7 CFU/ml. General fungi were detected at 14 sites, and its had average numbers were 3.9 CFU/ml. The correlation coefficient was calculated value as relation index between the microbial population sizes and environmental factors in groundwater. In case of HPC-NA, the correlation coefficient value with dissolved oxygen was 0.087 But it showed negative correlation coefficient with other factors. In case of HPC-YEPD, the correlation coefficient value with pH, temperature and nitrate were 0.0957, 0.0019 and 0.0151 respectively. It was concluded that the population size of HPC-NA were influenced by the order of temperature, dissolved oxygen, pH and the depth of wells and that HPC-YEPD were influenced by the order of pH, dissolved oxygen, nitrate, the depth of wells and temperature.

• Journal of the Korean Society of Radiology
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• v.9 no.4
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• pp.187-195
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• 2015

The active transport characteristics of anions of cell membrane model which irradiated by $^{60}Co\;{\gamma}-ray$ was investigated. The cell membrane model used in this experiment was a sulfonated copolymerized membrane of poly(1-methyl-4-vinylpyridiniumiodide-co-divinylbenzene : MeVP-DVBI). First, the initial flux of $OH^-$ and $Cl^-$, $Na^+$ of membrane which was not irradiated was decreased with increase of thickness of membrane $80-200{\mu}m$, increased with increase of NaOH concentration 0-0.5mol/L and MeVP-DVBI concentration 20-80% was increased with initial flux of $OH^-$ and $Cl^-$, decreased with initial flux of $Na^+$. Second, the initial flux of membrane which was irradiated was less than that. And the driving force of pH of irradiated membrane was significantly increased more than membrane which was not irradiated. The initial flux of the $OH^-$ ion was decreased with increase of $H^+$ ion concentration. As selective transport of $OH^-$ and $Cl^-$ of cell membrane model were abnormal, cell damages were appeared at cell.

• Journal of Ocean Engineering and Technology
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• v.21 no.3 s.76
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• pp.58-64
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• 2007

New artificial fishing reefs are developed using modified sulfur concrete. Modified sulfur concrete, which is made of by-product aggregates and modified sulfur binder, has good properties, including high density, less water absorption, high strength, high salt resistance, and good affinity for living organisms. This paper shows the mechanical properties of modified sulfur concrete and its field tests under the sea. We have found that the pH-neutral materials attach microalgae and seaweed more readily, compared to the pH-high materials.

• Journal of Ocean Engineering and Technology
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• v.22 no.3
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• pp.103-108
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• 2008

Topics discussed in this paper are engineering design of artificial reefs, design considerations of compressive strength and pH, materials of silica fume concrete and volcanic stones for reef construction, and field monitoring of artificial reefs. Six artificial reefs were deployed offshore at Biyangdo in July 2006, and succession patterns on the reefs were investigated bimonthly from July 2006 to October 2007. The spore-bag method, which has been widely used in Korea for the attachment of seaweed on artificial reefs, was applied to the developed reefs using the kelp Ecklonia cava, which is the dominant species in Jeju, and recruitment and growth patterns were observed.

• Journal of the Korea Convergence Society
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• v.9 no.7
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• pp.149-154
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• 2018

This article intended to examine the anti-plaque activity of 4 essential oils of Lavender, Tea tree, Eucalyptus, Lemongrass against Streptococcus mutans. In the results of measuring the anti-plaque effect against Streptococcus mutans, Minimum anti-adhesive concentration of Lavender oil was 1.0% and that of Tea tree, Eucalyptus, lemongrass essential oils was 0.5 %. Also, it was confirmed that the essential oils have the effect of inhibiting acid generation by Streptococcus mutans. It was confirmed that pH of the concentration was lowered by the acid generation under the MAC by measuring pH of the solution after incubating Streptococcus mutans and the essential oils in the thermostatic bath varying their concentration. From these results, the essential oils, particularly, Tea tree, Eucalyptus, Lemongrass essential oils are the natural material inhibiting the plaque generation and the potential that they can be used to develop the oral care products was confirmed.

• Journal of Korean Society of Water and Wastewater
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• v.24 no.4
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• pp.395-406
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• 2010

In this study, anaerobic digestion, electro-oxidation and electro-fenton oxidation processes were investigated to reduce oily refinery sludge. Anaerobic digestion process was not suitable for oily activated sludge reduction because of characteristics itself and, as experimental results revealed, reduction efficiency was low for electro-oxidation process. However, 40% total suspended solid reduction of oily activated sludge was obtained by electro-fenton oxidation process, operating at pH=1, 0.5 A and $Fe^{2+}$:$H_2O_2$ ratio = 1:30. In addition, higher reduction efficiency was obtained as reaction time was increased (30, 60, 90, 120 min) despite of low $H_2O_2$ concentration. From the results, it has been investigated that electro-fenton oxidation is efficient process for oily activated sludge reduction.

• Journal of Hydrogen and New Energy
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• v.25 no.4
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• pp.344-354
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• 2014

Activated charcoal supported nickel molybdenum carbide (carburized Ni-Mo/AC) catalysts were prepared by wet-impregnation followed by temperature-programmed carburization using 20% $CH_4/H_2$ gas. The effects of pH and initial Ni/Mo mole ratio during wet-impregnation step on the characteristics of the carburized Ni-Mo/AC catalysts were investigated using ICP, XRD, XPS, BET and $CO_2$-TPD techniques, and correlated with the catalytic activity of the carburized Ni-Mo/AC in methane dry reforming reaction. Comparison of the results of methane dry reforming reaction kinetics with the results of characterization of the carburized Ni-Mo/AC catalyst showed that the catalytic activity in methane dry reforming reaction was higher at higher initial Ni/Mo mole ratio or at lower pH(3~natural value). This phenomenon was related to the crystal size of metallic Ni in the carburized Ni-Mo/AC catalyst.

• Journal of the Korean Society of Radiology
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• v.11 no.2
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• pp.157-165
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• 2017

The active transport characteristics of $K^+$ and $Na^+$ pumping system of cell membrane model which irradiated by high energy x-ray(linac 6MeV) was investigated. The cell membrane model used in this experiment was a $Na^+$ type sulfonated copolymerized membrane of styrene and divinylbenezene. The initial flux of the ion was increased with increase of both $H^+$ ion concentration. In this experiment range(pH 1.5-5, temperature $36.5^{\circ}C$), the initial flux of $K^+$ which was not irradiated by radiation was found to be from $2.09{\times}10^{-4}$ to $1.32{\times}10^{-3}mole/cm^2{\cdot}h$ and that of $Na^+$ from $7.09{\times}10^{-4}$ to $1.09{\times}10^{-3}mole/cm^2{\cdot}h$. the initial flux of $K^+$ which was irradiated by radiation was found to be from $21.0{\times}10^{-4}$ to $16.7{\times}10^{-3}mole/cm^2{\cdot}h$ and that of $Na^+$ from $62.0{\times}10^{-4}$ to $20.6{\times}10^{-3}mole/cm^2{\cdot}h$. The ratio $K^+$/$Na^+$ of membrane was about 1.10. And the driving force of pH of irradiated membrane was significantly increased about 9-20 times than membrane which was not irradiated. As active transport of $K^+$ and $Na^+$ of cell membrane model were abnormal, cell damages were appeared at cell.

• The Journal of Engineering Geology
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• v.10 no.1
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• pp.51-62
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• 2000

The $CO_2$-richrich water pumps or springs out at two sites (Sinchon and Kohran) consisting of Cretaceous sedimentary rocks in Kyungpook area. The water has been long known as its soda pop-liketaste and therapeutic effect against calcium deficit, stomach and skin troubles, etc. The water arecharacterized by a high $CO_2$ concentration $(P_{CO2}=0.29~l.01 atm)$ and electrical conductance (1,093~2,810$\mu$S/cm). The $CO_2$-rich water belongs to Ca(Na)-$HCO_3$ type in chemical classification. The contents of Ca, Mg, Na, HCO$_3$ and Fe of $CO_2$-rich water show much higher values than those of general groundwater Environmental isotopic data $(^2H/^1H, ^{18}O/^{16}O and ^3H/^1H)$ indicate that the water is ofmeteoric origin recharged after 1950s. The $CO_2$ in the springs seems to be originated from deep-seatedsource related to acidic porphyry and granite nearby sedimentary rocks. Carbonate minerals and albiteare likely to be the major source minerals of the dissoved inorganic constituents in the $CO_2$-rich water.The equilibrium state between major minerals and $CO_2$-rich water was calculated by a thermodynamicprogram.

• 한국지구물리탐사학회:학술대회논문집
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• 2005.05a
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• pp.267-272
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• 2005

Geophysical surveys were performed in three abandoned mines: Jangpoong, Kwangyang, Imchon. The main objectives of the researches include delineating the pathways of leachate from acid mine drainage(AMD), mapping buried rock wastes and tailings, detecting drainage pipes, and investigating the gallery and membrane, if they exist, Geophysical responses were well correlated with the results from water sample data(i.e., pH, EC, heavy metal contents, $SO_4^{-2}$). Main pathways of the leachate were successfully detected in electrical resistivity sections and self-potential(SP) profiles, whereas waste rocks, drainage pipes, and membranes were effectively located by incorporating seismic refraction, electrical resistivity and GPR methods.