• Journal of the Korean Electrochemical Society
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• 제5권3호
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• pp.99-105
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• 2002

This study investigated characteristics of ICR18650 batteries with different electrolyte compositions in the range of $80^{\circ}C\~-30^{\circ}C$. ICR18650 cells using $1M\;LiPF_6,\;EC:\;DEC:\;DMC(3:5:5)\;and\; 1M\;LiPF_6,\;EC:\;DEC:\;DMC:\;EMC(3:5:4:1)$ electrolyte systems, which DMC and EMC solvent were added in $1M\;LiPF_6,\;EC:\;DEC$ electrolytes have high specific energy in the wide range of temperature. The specific energy of ICR18650 batteries using $1M\;LiPF_6,\;EC:\;DEC:\;DMC(3:5:5)\;and\; 1M\;LiPF_6,\;EC:\;DEC;\:\;DMC:\;EMC(3:5:4:1)$ electrolyte at $-30^{\circ}C\;was\;64\%\;and\;59\%$ of room temperature$(25^{\circ}C)$, respectively.

• The Korean Journal of Pesticide Science
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• 제16권2호
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• pp.163-170
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• 2012

Nineteen registered insecticides including 8 mixed formulations with buprofezin and 11 single formulations which is not including buprofezin were evaluated by spray application for their toxicity against adult and nymph of citrus mealybug, Planococcus citri. Five mixed formulations with buprofezin such as buprofezin 15EC+acetamiprid 4EC, buprofezin 10SC+clothianidin 3SC, buprofezin 20WP+dinotefuran 15WP, buprofezin 20SC+thiacloprid 5SC, and buprofezin 20SC+thiamethoxam 3.3SC showed high insecticidal activity (>93%) against nymph and adult of P. citri. Insecticidal activities of EPN 45EC, fenitrothion 50EC and methidathion 40EC in organophosphorous group showed 90 to 93% against nymph only. In addition to, insecticidal activities of acetamiprid 8WP, clothianidin 8SC, dinotefuran 20WG and thiamethoxam 10WG in neonicotinoids group showed above 90% against nymph only. In systemic and residual effect, five mixed formulations that was already proved to have high insecticidal activity showed low toxicity with below 60% against $3^{rd}$ instar nymph of P. citri in tomato and rose under greenhouse. Control efficacy of five mixed formulations with buprofezin was above 90%, 80% and 70% at 5 days after treatment (DAT), 10 DAT and 15 DAT, respectively.

• Journal of Bio-Environment Control
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• 제21권4호
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• pp.317-321
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• 2012

This study was carried out to investigate the effect of EC levels in nutrient solution on the growth of rose in coir substrate during the juvenile. Nutrient concentration were EC 0.6, 1.0, 1.4, and $1.8dS{\cdot}m^{-1}$. In spite of high concentration of nutrient solution was supplied, EC and inorganic ions content in the extract of substrate was no difference by 22 days after planting. After that, they was rapidly increased with higher concentration of nutrient solution. Number of shoot was highest in EC $1.8dS{\cdot}m^{-1}$ at 2nd growth cycle, 90 days after planting, after that was showed a tendency to increase with increasing nutrient concentration, but was no significant difference among treatment except EC $0.6dS{\cdot}m^{-1}$. Judging by results of growth of rose and contents of inorganic ion in extracts of media, our experiment suggests that the suitable nutrient concentration is EC $1.8dS{\cdot}m^{-1}$ until 90 days and then EC $1.4dS{\cdot}m^{-1}$ until 165 days after planting that is more higher than conventional nutrient concentration for absorption by coir.

• Journal of Environmental Science International
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• 제30권8호
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• pp.605-612
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• 2021

Supply electrical conductivity (EC) concentration of the nutrition solution is an important factor in the absorption of nutrients by plants and the management of the root zone, as it can control the vegetative/reproductive growth of a plant. Paprika usually undergoes its reproductive and vegetative growth simultaneously. Therefore, ensuring proper growth of the plant leads to increased yield of paprika. In this study, growth characteristics of paprika were examined according to the EC concentration of a coir and a rockwool substrate. The supply EC was 1.0, 2.0, and 4.0 mS·cm^-1 applied at the initial stages of the growth using the rockwool (commonly used by paprika farmers) and the coir substrate with a chip and dust ratio of 50:50 and 70:30. For up to 16 weeks of paprika growth, EC concentrations of 1.0 and 2.0 mS·cm^-1 were found to have a greater effect on the growth than EC at 4.0 mS·cm^-1. The normality (marketable) rate of fruit, the soluble solid content, and paprika growth showed that the coir was generally better than the rockwool regardless of the supply EC concentration. The values of the yield per plant at an EC concentration of 4.0 mS·cm^-1 was mostly similar at 1.6 kg (coir 50:50), 1.5 kg (coir 70:30) and 1.5 kg (rockwool), but the yield of the rockwool was 88%, which was lower than 98% and 94% yield of the coir substrate. Therefore, this concludes that coir substrate is more effective than rockwool at improving paprika productivity. The results also suggest that the use of coir substrate for paprika has many benefits in terms of reducing production costs and preventing environmental destruction during post-processing.

• Journal of Korea Water Resources Association
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• 제57권2호
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• pp.111-125
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• 2024

The study has examined alterations in groundwater quality by investigating the influence of rainfall on electrical conductivity (EC) and nitrate concentration in the groundwater of the Geum River Basin in South Korea. Mann Kendall and Sen's Slope estimator were employed to analyze the trends and estimate the trend's magnitude. The administrative map of the study area was utilized to assess the trends of these parameters within each administrative region. Seventeen years (from 2005 to 2021) of data on EC, groundwater levels (GWL), precipitation, and six years (from 2015 to 2020) of nitrate concentration data were utilized for this analysis. The results indicate that, in most administrative regions, there has been an increase in nitrate concentration, and EC, whereas precipitation has seen a slight decrease in a downstream and an increasing trend in upstream. The correlation coefficients calculated between these parameters reveal that there is no direct impact of precipitation on nitrate and EC, but a negative correlation was observed between GWL and EC. The most significant increasing trend in nitrate concentration was observed in two districts (Iksan and Gunsan ), which correspond to regions with significant agricultural activity; about 50% of these districts area are used for agricultural activities.

• Corrosion Science and Technology
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• 제12권1호
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• pp.56-64
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• 2013

An Eectrolytic Corrosion(EC) test method was evaluated by the comparison with Copper Accelerated Acetic Salt Spray(CASS) and Neutral Salt Spray(SS) tests. Those methods were applied in order to evaluate corrosion resistance of Ni-Cr plated and Zn-plated Fe substrates. The correlations between results obtained by different test methods were investigated. Results showed that the electrochemical method such as the EC test method was superior to the conventional methods such as CASS and SS, in terms of the quantitative accuracy and the test-time span. Furthermore, the EC test method provided the useful means to estimate the initiation of corrosion of each layer by monitoring the rest potentials of the coated layers such as Ni, Cr, and Zn on Fe substrate. With regard to test time spans, the EC test provided the 78 times and 182 times faster results than the CASS test in cases of $Fe+5{\mu}m$ $Ni+0.5{\mu}m$ Cr and $Fe+20{\mu}m$ $Ni+0.5{\mu}m$ Cr respectively, while the EC test was 85 times faster results than the Salt Spray test in the case of $Fe+20g/m^2$ Zn. Therefore, the EC test can be the better method to evaluate the resistance to corrosion of coated layers than the conventional methods such as the SS test and the CASS.

• Proceedings of the Korean Vacuum Society Conference
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.407.1-407.1
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• 2016

Electrochromism is defined as a phenomenon which involves persistently repeated change of optical properties between bleached state and colored state by simultaneous injection of electrons and ions, sufficient to induce an electrochemical redox process. Due to this feature, considerable progress has been made in the synthesis of electrochromic (EC) materials, improvements of EC properties in EC devices such as light shutter, smart window and variable reflectance mirrors etc. Among the variable EC materials, solid-state inorganics in particular, metal oxide semiconducting materials such as nickel oxide (NiO) have been investigated extensively. The NiO that is an anodic EC material is of special interest because of high color contrast ratio, large dynamic range and low material cost. The high performance EC devices should present the use of standard industrial production techniques to produce films with high coloration efficiency, rapid switching speed and robust reversibility. Generally, the color contrast and the optical switching speed increase drastically if high surface area is used. The structure of porous thin film provides a specific surface area and can facilitate a very short response time of the reaction between the surface and ions. The large variety of methods has been used to prepare the porous NiO thin films such as sol-gel process, chemical bath deposition and sputtering. Few studies have been reported on NiO thin films made by using sol-gel method. However, compared with dry process, wet processes that have the questions of the durability and the vestige of bleached state color limit the thin films practical use, especially when prepared by sol-gel method. In this study, we synthesis the porous NiO thin films on the fluorine doped tin oxide (FTO) glass by using sputtering and anodizing method. Also we compared electrical and optical properties of NiO thin films prepared by sol gel. The porous structure is promised to be helpful to the properties enhancement of the EC devices.

• Journal of Bio-Environment Control
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• 제7권3호
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• pp.246-252
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• 1998

This study was carried out to investigate the quality of ground water for hydroponics in Kyeongnam area in 1995. Water samples were collected and analyzed from 77 wells in green houses throughout Kyeongnam area. The values of several components in well water were as follows ; 7.4 in pH, 0.46dS/m in EC, 0.3mg/L in N $H_{4}$-N, 25.4mg/L in $Ca^{2＋}$, 42.6mg/L in C $l^{[-10]}$ and 72.5mg/L in S $O_{4}$$^{2-}$. The pH value showed high positive significance of correlationships with $Ca^{2＋}$ and EC. Also, the EC value showed high positive significance with N $a^{＋}$, $Ca^{2＋}$, S $O_{4}$$^{2-}$, $Mg^{2＋}$ and C $l^{[-10]}$ .

• Asian Journal of Atmospheric Environment
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• 제11권2호
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• pp.79-95
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• 2017

A number of field studies have provided evidence that biomass burning is one of the major global sources of atmospheric particles. In this study, we have collected $PM_{2.5}$ emitted from biomass burning combusted at open burning and laboratory chamber situations. The open burning experiment was conducted with the cooperation of 9 farmers in Chiba Prefecture, Japan, while the chamber experiment was designed to evaluate the characteristics of chemical components among 14 different plant species. The analyzed categories were $PM_{2.5}$ mass concentration, organic carbon (OC), elemental carbon (EC), ionic components ($Na^+$, ${NH_4}^+$, $Ca^{2+}$, $Mg^{2+}$, $K^+$, $Cl^-$, ${NO_3}^-$ and ${SO_4}^{2-}$), water-soluble organic carbon (WSOC), water-insoluble inorganic carbon (WIOC), char-EC and soot-EC. OC was the dominant chemical component, accounting for the major fraction of primary $PM_{2.5}$ derived from biomass burning, followed by EC. Ionic components contributed a small portion of $PM_{2.5}$, as well as that of $K^+$. In some cases, $K^+$ is used as biomass burning tracer; however, the observations obtained in this study suggest that $K^+$ may not always be suitable as a tracer for biomass burning emissions. Also, the results of all the samples tested indicate relatively low values of char-EC compared to soot-EC. From our results, careful consideration should be given to the usage of $K^+$ and char-EC as indicators of biomass burning. The calculated ratios of WSOC/OC and WIOC/OC were 55.7% and 44.3% on average for all samples, which showed no large difference between them. The organic materials to OC ratio, which is often used for chemical mass closure model, was roughly estimated by two independent methods, resulting in a factor of 1.7 for biomass burning emissions.

• The Journal of Korean Medicine
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• 제38권4호
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• pp.11-40
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• 2017

Objectives: We investigated whether a mixture of the main component of pomegranate concentrated powder (PCP) with appropriate proportions of Eucommiae Cortex (EC) and Achyranthis Radix (AR) could act synergistically as an effective treatment for osteoarthritis (OA). Methods: In order to evaluate the effects of PCP, EC, and AR against OA, knee thicknesses, maximum extension angle of each knee, anti - inflammation effects, the transcript levels of chondrogenic genes mRNA expressions in femur and tibia articular cartilage (AC) with synovial membrane (SM) were analyzed. In addition, the histopathology and immunohistochemistry of the femur and tibia AC or SM were performed. Results: The surgically-induced OA signs in rats were significantly inhibited by 28 days of continuous treatment of PCP, EC and AR single formulas, and PCP with EC:AR mixed formulas. Especially, PCP with EC:AR 4:1, 2:1 and 1:1 mixed formula treatment constantly showed significantly more favorable inhibitory activities, as compared with those of single formula of PCP, EC and AR treated rats. Conclusion: PCP and EC:AR 4:1 mixed formula showed similar OA refinement effects through potent anti-inflammatory pathways as compared with those of diclofenac treatment, and showed additional chondrocyte proliferating effects on the both femur and tibia AC.