• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.676-683
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• 2003

A laboratory experiment using artificial fracture rocks was used to understand the 3-dimensional dispersion of a tracer and the mixing process in a fractured network. In this experiment, 12cm polystyrene foam cubes with two electrodes for monitoring electric conductivity (EC) were used as artificial fractured rocks. Distilled water with 0.5mS/m was used as a tracer in water with 35mS/m and the difference of EC between the tracer and the water was monitored by a multipoint simultaneous measurement system of electrical resistance. The results showed that even if the fracture arrangement pattern was not straight in the direction of the flow, the tracer did not diffuse along individual fractures and an oval tracer plume, which was the distribution of tracer concentrations, tended to be form in the direction of the flow. The vertical cross section of the tracer distribution showed small diffusivity in the vertical direction. The calculated total tracer volume passing through each measurement point in the horizontal cross section showed while that the solute passed through measurement points near the direction of hydraulic gradient and in other directions, the passed tracer volumes were small. Using Peclet number as a criterion, it was found that the mass distribution at the fracture intersection was controlled in the stage of transition between the complete mixing model and the streamline routing model.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.4
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• pp.554-559
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• 2004

The objective of the present study was to investigate the accuracy of mastitis diagnostic indicators for different dairy goat breeds. Biweekly milk samples were collected from individual half mammary gland of seven Saanen and seven Alpine dairy goats in the period of 40 to 120 days in milk. With threshold value set at 2.8 and 3.1 for Alpine and Saanen dairy goats, respectively, log (SPC) offered good sensitivity (0.89, 0.93), specificity (0.88, 0.95), positive predictive value (0.75, 0.85) and negative predictive value (0.95, 0.98) as a mastitis diagnostic tool. The correlations of log (SPC) with milk yield, log (SCC), ALP, LDH, $Na^{+}$, $K^{+}$ and EC were significant in Saanen dairy goats (p<0.05), with the highest correlation coefficient (0.653) existing between log (SPC) and log (SCC). The correlations of log (SPC) with milk yield, milk fat, milk protein, log (SCC), $Na^{+}$, $K^{+}$, EC were significant in Alpine dairy goats (p<0.05), with the highest correlation coefficient (0.416) existing between log (SPC) and log (SCC). There were different best-fit regression equations with different multiple diagnostic indicators for Saanen and Alpine dairy goats. In conclusion, different breeds of dairy goats may have to adapt different mastitis diagnostic parameters for a better diagnosis.

• Korean Journal of Plant Resources
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• v.28 no.4
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• pp.533-540
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• 2015

Germination properties, leachate electrical conductivity (EC), and inorganic compound leaching were analyzed to ascertain the storage ability and change of physiological characteristics during storage of Hippophae rhamnoides seeds. Seeds were placed in an incubator at 25℃ and sown in different soil media (sand, vermiculite and horticultural substrate) after being stored for 6, 18 and 30 months at 2℃. All germination properties decreased in accordance to an increase of the seed storage period. Compared with the seed storage for 18 months, germination percentage (GP), germination performance index (GPI), and germination value (GV) of seeds stored for 30 months decreased by more than 50%. When the seeds were sown in different soil media in a greenhouse, those germination properties were similar to the seeds germinated in an incubator, and mean germination time, GPI and GV had a significant difference except GP among soil media. EC and inorganic ion concentration had a strong positive correlation with the seed storage period, but the ratios of inorganic ions from stored seeds revealed that K⁺/Mg²⁺ and Na⁺/Mg²⁺ were inversely correlated with the storage period.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.2
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• pp.100-104
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• 2004

This study was conducted to investigate the effect of the salinity on growth, inorganic ion content, and photosynthetic rate ($\textrm{P}^{N}$) in Korean ginseng (Panax ginseng C.A. Meyer) with complex fertilizer (CF) and NaCl concentrations. The salinity was applied to plant using NaCl and CF, and controlled an EC as 0.0, 1.0, 2.0 and 3.0 dS $\textrm{m}^{-1}$. The salinity treated three times at 35, 42 and 49 d after transplanting. The leaf area in different electrical conductivity (EC) decreased only the higher NaCl 1.0 dS $\textrm{m}^{-1}$. The root growth increased with CF and especially, it was two times higher at 3.0 dS $\textrm{m}^{-1}$ than that of control. But the root growth sharply decreased with NaCl compared to CF. The light saturation point of Korean ginseng was around 100 $\mu\textrm{mol}\;\textrm{m}^{-2}\textrm{s}^{-1}$ photosynthetically active radiation (PAR), and $\textrm{P}^{N}$ increased as CF increased but decreased with NaCl especially at the late growth stage. The $\textrm{Na}^{+}$ content in Korean ginseng increased sharply with NaCl.

• Journal of Soil and Groundwater Environment
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• v.17 no.4
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• pp.19-26
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• 2012

The influence of operation time on electrokinetic restoration was investigated to remove salts from sulfate-accumulated greenhouse soil. Operation time is directly related to the process cost, therefore, we determined the relationship between operation time and removal of salts. Nitrate and sodium were removed almost completely within 2 weeks, chloride and calcium was removed in proportion to the operation time. Sulfate was accumulated at the center of anode and cathode. The soil electrical conductivity (EC), an indicator for soil salinity, showed similar shape with the residual sulfate after electrokinetic treatment. The soil EC was not changed after 2 weeks, however, the energy consumption increased with operation time. Based on the experimental results, most salts except sulfate were removed within 2 weeks, but sulfate was not removed during same time period. For the further removal of sulfate, longer operation time is in need.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.6
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• pp.615-622
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• 2017

This study was conducted to evaluate the odor reduction efficacy of the dip injection wet scrubber (DIWS) using tap water as washing fluid. The $NH_3$ and $H_2S$ removal efficiency of 7 day batch operated DIWS was evaluated twice over a total of 14 days of experiment. The $NH_3$ removal efficiency ranged from 26 to 37%. The $H_2S$ removal efficiency was between 22 and 30%. The pH of the washing fluid maintained below 8 and the $NH_4{^+}$ concentration tended to keep constant around 350 ppm after 5 days of washing-fluid replacement. Therefore, the 5-day washing fluid replacement interval is more preferable than the 7-day interval. The $NH_4{^+}$ concentration and the electrical conductivity (EC) showed a high correlation. The EC measurement can be used as an alternative to conventional $NH_4{^+}$ concentration measurement method for real time monitoring of washing fluid condition.

• Journal of Environmental Science International
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• v.32 no.9
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• pp.627-634
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• 2023

Tire wear particles(TWPs), regarded as a microplastic, is generated in significant quantities each year and exist in various spaces and have a negative impact on the surrounding environment. Particularly, roadside environments fall within the direct influence of TWPs, necessitating proactive investigation for contamination management and response. Therefore, this study aimed to investigate the soil acidity and electrical conductivity(EC) and TWPs in the roadside soil of six sites based on traffic volume. The analysis revealed that the soil in all sites exhibited subacidity, and there were no significant differences in EC. Microscopic and FT-IR analysis revealed the presence of microscopic particles in soil samples that exhibited common visual characteristics of TWPs. In the road with the highest traffic volume, 48,300 TWPs were detected per unit area. Furthermore, a proportional relationship between traffic volume and TWPs particles was established. However, influences other than traffic volume on TWPs particle count within the soil were observed. Therefore, for the management of TWPs contaminated roadside soil, a proactive response is necessary in areas with high traffic volumes. However, in order to effectively address the factors contributing to the generation and dispersion of TWPs, further research is required with a multidimensional approach.

• Journal of Bio-Environment Control
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• v.21 no.3
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• pp.186-191
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• 2012

Experiments were conducted to investigate the effect of fertigation (fertilizer-added irrigation) on soil EC (electrical conductivity), nitrogen and calcium content in soil, vine growth and fruit yield of oriental melon (Cucumis melo L. var. makuwa Mak.). Soil EC was increased with the frequency of fertigation (Yamazaki's solution for melon, 900 L/1,000 plants, each time) up to $0.8dS{\cdot}m^{-1}$ as compared to that of conventional irrigation ($0.2dS{\cdot}m^{-1}$). Ca content in soil also increased in fertigation fields. Vine dry weigh (20 days after planting) was significantly increased in fertigation plot. Markedly increases in marketable fruit yield and lower rate of off-shape fruit were recorded with the increase in fertigation frequency. Mean fruit weight and soluble solids contents ($^0Brix$) in fruit were not affected by fertigation. Fresh weight loss during storage was significantly higher in fruits harvested from 2 times fertigation (09:00 and 18:00) plot than conventional irrigation and the 1 time fertigation ones.

• Proceedings of the KIEE Conference
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• 1998.11c
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• pp.822-824
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• 1998

The lithium polymer battery with polymer electrolyte is expected as a safe and long cycle life battery. This paper reports primarily the recent development results of a solid polymer electrolyte, which is a key point of the secondary battery system. The new type of polymer electrolyte was prepared under a dry Ar atmosphere by dissolving $LiCIO_4$ in a matrix of EC, PC and then dispersing polyacrylonitrile(PAN). Also adding some inorganic filler $Al_2O_3$. The dispersed solution heated at $120^{\circ}C$. The polymer electrolyte were characterized by EIS(Electrochemical Impedance Spectroscopy), TGA(Thermo Gravimetric analysis), DMA(Dynamic Mechanical Analyzer), DSC (Differential Scanning Calorimetry). The lithium ion yield is 0.29 when PAN-$Al_2O_3$ which was applied DC 5mV. The ionic conductivity of PAN, PAN-$Al_2O_3$ polymer electrolytes were showed $1.0{\times}10^{-4}S/cm$, $8.4{\times}10^{-4}S/cm$ at room temperature. When inorganic filler was added in the polymer electrolyte, ionic conductivity and lithium yield more larger than without inorganic filler.

• Journal of Microbiology and Biotechnology
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• v.24 no.12
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• pp.1707-1718
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• 2014

In this study, the phylogenetic diversities of bacterial and archaeal communities in a plant-microbial fuel cell (P-MFC) were investigated together with the environmental parameters, affecting its performance by using rice as a model plant. The beneficial effect of the plant appeared only during a certain period of the rice-growing season, at which point the maximum power density was approximately 3-fold higher with rice plants. The temperature, electrical conductivity (EC), and pH in the cathodic and anodic compartments changed considerably during the rice-growing season, and a higher temperature, reduced difference in pH between the cathodic and anodic compartments, and higher EC were advantageous to the performance of the P-MFC. A 16S rRNA pyrosequencing analysis showed that the 16S rRNAs of Deltaproteobacteria and those of Gammaproteobacteria were enriched on the anodes and the cathodes, respectively, when the electrical circuit was connected. At the species level, the operational taxonomic units (OTUs) related to Rhizobiales, Geobacter, Myxococcus, Deferrisoma, and Desulfobulbus were enriched on the anodes, while an OTU related to Acidiferrobacter thiooxydans occupied the highest proportion on the cathodes and occurred only when the circuit was connected. Furthermore, the connection of the electrical circuit decreased the abundance of 16S rRNAs of acetotrophic methanogens and increased that of hydrogenotrophic methanogens. The control of these physicochemical and microbiological factors is expected to be able to improve the performance of P-MFCs.