• Journal of the Korean Electrochemical Society
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• v.5 no.3
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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.

• Journal of Bio-Environment Control
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• v.19 no.2
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• pp.70-76
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• 2010

To investigate the ground water quality status for paprika hydroponics for export, its pH, EC (electrical conductivity) and inorganic ion concentrations were analyzed in Gangwan-do (27 samples), Gyeonsangnam-do (77 samples) and Jeollanam-do (54 samples) from November 2008 to September 2009. The average values of several components in ground water were as follows; 7.20 (6.57~7.54) in pH, 0.31 (0.05~0.49) $dS{\cdot}m^{-1}$ in EC, 97.81 (35.37~161.11) in $HCO_3$, 5.68 (0.45~15.48) in T-N, 0.67 (0.15~0.70) in P, 2.53 (0.59~6.70) in K, 35.68 (4.15~80.70) in Ca, 7.35 (1.46~14.87) in Mg, 17.89 (3.31~34.82) in Na, 0.01 (0~0.05) in Fe, 0.09 (0~0.51) in Mn, 0.06 (0~0.07) in Zn, and 0.03 (0~0.10) $mg{\cdot}L^{-1}$ in Cu, respectively. The values of pH, EC, $HCO_3$, Ca, Mg and Na in ground water were different depending on areas and farms. Frequency rates were 92.6% of pH 5.0~8.0, 89.3% of EC < 0.5 $dS{\cdot}m^{-1}$, 69.5% of $HCO_3$ < 100, 97.5% of Na < 30, 88.5% of Ca < 40, 97.5% of Mg < 20, 90.1% of Fe < 0.05, 99.6% of Mn < 0.6, and 98.3% of Zn < 0.5 $mg{\cdot}L^{-1}$, respectively, which can be used for nutrient fertilizers in hydroponics. The percentage of suitable water quality was 46.3% as 70 sites among the all analyzed ions. The pH value showed high significance of correlations with EC, Mg, $HCO_3$, Na, and Fe. Also the EC value showed high positive significance with T-N, K, Ca, Mg, $HCO_3$, Na and Mn.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1257-1257
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• 2001

Fourier transform near infrared (FT-NIR) spectroscopy was used as a rapid method to measure the $^{o}Brix$ content and to discriminate between different must samples in terms of their fee amino nitrogen (FAN) values. FT-NIR spectroscopy was also used as a rapid method to discriminate between Chardonnay wine samples in terms of the status of the male-lactic fermentation (MLF). This was done by monitoring the conversion of malic to lactic acid and thereby determining whether MLF has started, is underway or has been completed followed by classification of the samples. Furthermore, FT-NIR spectroscopy was applied as a rapid method to discriminate between table wine samples in terms of the ethyl carbamate (EC) content. EC in wine can pose a health threat and need to be monitored by determining the EC content in relation to the regulatory limits set by the authorities. For each of the above mentioned parameters, $QUANT+^{TM}$ methods were built and calibrations derived and it was found that a very strong correlation existed in the sample set for the FT-NIR spectroscopic predictions of $^{o}Brix$ (r = 0.99, SECV = 0.306), but the correlations for the FAN (r = 0.61, SECV = 272.1), malic acid (r = 0.58, SECV = 1.06), lactic acid (r = 0.51, SECV = 1.14) and EC predictions (r = 0.47, SECV = 3.67) were not as good. Soft Independent Modeling by Class Analogy (SIMCA) diagnostics and validation was applied as a sophisticated discrimination method. The must samples could be classified in terms of their FAN values when SIMCA was applied, obtaining results with recognition rates exceeding 80%. When SIMCA diagnostics and validation were applied to determine the progress of conversion of malic to lactic acid and the EC content, again results with recognition rates exceeding 80% were obtained. The evaluation of the applicability of FT-NIR spectroscopy measurement of FAN, $^{o}Brix$ values, malic acid, lactic acid and EC content in must and wine shows considerable promise. FT-NIR spectroscopy has the potential to reduce the analytical times considerably in a range of measurements commonly used during the wine making process. Where conventional FT-NIR calibrations are not effective, SIMCA methods can be used as a discriminative method for rapid classification of samples. SIMCA can replace expensive, time-consuming, quantitative analytical methods, if not completely, at least to some extent, because in many processes it is only needed to know whether a specific cut off point has been reach or not or whether a sample belongs to a certain class or not.

• Korean Journal of Microbiology
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• v.43 no.3
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• pp.217-221
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• 2007

The domestic cultured Campbell's Early and Geubong grapes were fermented far the production of red wines with the isolated wild yeast Saccharomyces cerevisiae IJ850. For the isolation of wild yeast, Geubong and Campbell's Early grapejuices were naturally fermented at room temperature for 6 days without adding stater culture. The strain isolated from Geubong which has 1.8 times higher fermentative ability than the strains isolated Campbell Early was selected. The selected strain was identified by using 26S rDNA sequencing. The strain showed 99.7% of similarity with Saccharomyces cerevisiae and thus identified as Saccharomyces cerevisiae IJ850. It was investigated the fermentative ability as the start culture. For the production of grapewine, the final sugar concentrations of grapejuices were adjusted to the $25^{\circ}Brix$ with anhydrous glucose. The grapejuices were fermented at room temperature for 10 days in the air-locked bottles filled with $CO_2$ gas. The final yield and alcohol concentration of Campbell's Early and Geubong grapewines fermented with the isolated wild yeast were 80.8%, 11.0% and 87.8%, 13.0%, respectively. Between the isolated wild yeast S. cerevisiae IJ850 and the commercial yeast S. cerevisiae EC1118, total acidities of grapewines produced with wild yeast were lower than those produced with the commercial yeast. The pH values and the values of color analysis of grapewines produced with both strains were similar. The total phenol contents of campbell's Early and Geubong wines produced with the isolated yeast and the commercial yeast were obtained in the range of 75 to 125mg/L. In conclusion, S. cerevesiae IJ850 isolated from the domestic cultured Geubong grape is able to use to produce grapewines as stater culture.

• Journal of Environmental Science International
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• v.9 no.3
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• pp.253-259
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• 2000

The purpose of this study is to investigate the physicochemical characteristics of salinization of groundwater at the estern area of Cheju island. For this purpose, the major ions of groundwater, spring water are analyzed. The concentration of $Cl^-$ and Na^++K^+$/ contained in the groundwater at near the coastline are higher than those at inland area away from the coastline. The water quality components of groundwater observed at this area can be classified into 4 types such as Na-Cl, $HCO_3, Na-Cl-HCO_3$ and Ca-HCO$_3$. The concentration ratio of $SO_4^1 to Cl^- is 0.1354(R^2=0.972)$ at this area. This value is very similar with Dittomer's ratio of 0.13. For Na^+, K^+, and Mg^{2+}/ versus Cl^-$, their ratios also show a significant relationship between sea water and groundwater in this area. From the chloride-bicarbonate ratio, it can be estimated that the intrusion distance of seawater from coastline to inland area is 2.8km at Onpyung-Nansan, Sangdo and Pyungdae areas, and 5.4km at Kosung-Susan area. The mixing ratio between seawater and fresh water by the intrusion of seawater is decreased with the distance toward inland from coastline. This ratio(fresh water : seawater) is 80:20 in spring water adjacent the coastlines, Onpyung area and 99.8:0.2 in the well at No.3 of Susan located at inland away from the coastline. The concentration of $Na^+$ observed at field is 25~45% lower than that theoretically calculated by this mixing ratio. Based on the data of EC, the equipotential line of 500$\mu$mhos/cm is located at 4~5km poing at Kosung-Susan area and 2.5km point at the other area. The equation of correlation between $Cl^-$ concentration and EC values is $Cl^-$=0.1927EC-16.683 for the area lower than 500 $\mu$mhos/cm and $Cl^-$=0.2773EC for the area beyond 500 $\mu$mhos/cm.

• Journal of Forest and Environmental Science
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• v.16 no.1
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• pp.82-92
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• 2000

The pH, EC and anion of stemflow in Quercus mongolica and Q. variabilis were surveyed and analyzed in order to examine the relationship between watershed conservation function and flood control function of forest in quality and quantity in the Experiment Forests. College of Forest Sciences, Kangwon National University. The results were as follows: 1. pH values of rainfall ranged from 4.47 to 6.55(average: 5.39), and pH values of throughfall ranged from 4.07 to 6.25(average 5.45) for Q. mongolica and from 4.34 to 6.57(average : 5.62) for Q. variabilis, and thus pH values were not different between these two species. Also, pH values of stemflow from Q. mongolica ranged from 4.08 to 6.13(average 5.17) and those of stemflow from Q. variabilis ranged from 3.62 to 6.11(average : 4.68), and pH values of rainfall gave little influence on pH values of stemflow. But, pH values of stemflow in Q. mongolica and Q. variabilis appeard significantly lower in spring and than those in summer and autumn. 2. EC of rainfall was $3.0{\sim}62.6{\mu}s/cm$(average: $18.8{\mu}s/cm$), and EC of throughfall was $5.4{\sim}85.0{\mu}s/cm$(average : $25.1{\mu}s/cm$) for Q. mongolica and $5.0{\sim}253.0{\mu}s/cm$(average : $31.2{\mu}s/cm$) for Q. variabilis. Also, EC of stemflow from Q. mongolica ranged from 9.5 to $500.0{\mu}s/cm$(average : $81.8{\mu}s/cm$) and that of stemflow from Q. variabilis ranged from 11.5 to $534.5{\mu}s/cm$(average : $80.2{\mu}s/cm$). Seasonal EC of rainfall had little variation in the range of 20 to $30{\mu}s/cm$: EC of stemflow showed more than $100{\mu}s/cm$ from March to April and about $30{\mu}s/cm$ in summer period. Seasonal EC of stemflow varied so much and appeared high again from October to November. 3. $Cl^-$, $NO_3{^-}$ and $SO_4{^{2- }}$ concentrations of rainfall and throughfall were from 1 to 15ppm. and $PO_4{^{2- }}$ concentrations showed 0.57ppm and 0.23ppm in rainfall, 0.08ppm in Q. mongolica and 0.14ppm, 0.12ppm and 1.19ppm in Q. variabilis. Also, $Cl^-$, $NO_3{^-}$ and $SO_4{^{2-}}$ concentrations of stemflow were relatively higher than rainfall, and showed differences among seasons. $PO_4{^{2-}}$ concentration of rainfall and throughfall were not possible to observe, but $PO_4{^{2-}}$ concentrations of stemflow ranged from 0.08 to 31.99ppm(average : 3.22ppm) for Q. mongolica and that of stemflow ranged from 0.06 to 12.28ppm(average : 1.93ppm) for Q. variabilis.

• Elastomers and Composites
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• v.51 no.3
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• pp.226-232
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• 2016

We studied the photocatalytic functionality such as deodorant, antibacterial, fine dust collection efficiency of polyester-based non-woven fabric filter treated with self-actuated photocatalyst. According to UV/visible result, the UV-visible peak of visible-light responsive photocatalyst was found to be red shift at 420 nm sensitive in the visible light region. The deodorizing performance was shown to be reduced more than 80% even without dark conditions. Fine dust particles collection efficiency was shown to be excellent at the size of not only $2.5{\mu}m{\sim}10.0{\mu}m$ but also less than $2.5{\mu}m$. Also antimicrobial and antifungus was shown to be reduced more than 99.9%.

• Elastomers and Composites
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• v.57 no.3
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• pp.92-99
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• 2022

A large amount of particles on the roads is produced by friction between the vehicles and the road surface and by inflow from outside. The type of these particles affects the abrasion behavior of tire tread. In this study, road dust collected at a bus stop was separated by size, and the particles with sizes of 106-212 mm were analyzed. The particles were separated by density using NaI and NaBr aqueous solutions with densities in the range of 1.10-1.80 g/cm³ with the 0.10 g/cm³ interval. In the road dust sample, the following particle types were found: tire-road wear particles (TRWPs), asphalt pavement wear particles (APWPs), plant-related particles (PRPs), road paint wear particles (RPWPs), and plastic particles (PPs). The densities of TRWPs, APWPs, PRPs, and RPWPs were 1.20-1.80, >1.60, >1.10, and >1.40 g/cm³, respectively, while PPs were found in all density ranges. Additionally, many small mineral particles were observed on the particles. Order of the relative content of the particles was PRP > TRWP > APWP ~ RPWP > PP. APWPs that were stuck to TRWP could be removed by chloroform treatment. The shapes of the particles were characterized using their magnified images.

• Ecology and Resilient Infrastructure
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• v.3 no.1
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• pp.22-34
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• 2016

We developed a biologically-derived substance naphthoquinone (NQ) derivate for the eco-safe mitigation of harmful cyanobacteria blooms such as Microcystis and Dolichospermum. NQ was reacted with various substituents ($R_n$) to produce different NQ derivatives. We tested a total of 92 algicidal compounds based on the algicidal activity of Microcystis and Dolichospermum. 22 compounds of NQ were selected as candidates (algicidal activity >80% at $1{\mu}M$). Among them, NQ 40 compound showed the highest algicidal activity of 99.6% and 100% at the optimal concentration of $1{\mu}M$ on Microcystis and Dolichospermum, respectively. No algicidal effects of NQ 40 ($1{\mu}M$) were observed against non-target algae such as Stephanodiscus, Cyclotella and Peridinium. According to the results of acute eco-toxicity assessment, the $EC_{50}$ values of NQ 40 compound for Selenastrum capricornutum and Daphnia magna were 3.2 and $14.5{\mu}M$, respectively, and the $LC_{50}$ for Danio rerio was $15.7{\mu}M$. In addition, for D. magna chronic eco-toxicity assessment, no toxicity toward survival, growth and reproduction was observed. Therefore, we suggested the NQ 40 ($1{\mu}M$) compound as an alternative eco-safe algicidal substance to effectively mitigate harmful cyanobacteria blooms.

• Journal of Bio-Environment Control
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• v.4 no.1
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• pp.80-88
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• 1995

This survey has been conducted, mostly in inorganic ions, to get some basic data for the culture solution composition, analyzing water quality of some hydroponic farms. pH range was shown from 5.95 to 7.61 and the average of 6.75. Relatively wide range of EC, from 0.07 to 0.97 mS/cm and the average of 0.35 mS/cm were obtained. 19.5 percent of farms investigated showed over 0.5 mS/cm of EC, which means more careful culture solution composition and its management are needed in these farms. Na concentration ranged from 5.0 to 41.4 ppm and Cl concentration ranged from 10 to 99 ppm were shown and their average were 20.38 ppm and 35.16 ppm, respectively. Higher Na concentration compared to standard of 11.5 ppm was shown in 75% of farms and Higher Cl concentration compared to standard of 35.5 ppm was shown in 33.3% of farms. These concentration were considered rather high, which can cause salt accumulation in substrate mats. Ca and Mg concentrations were ranged from 1.60 to 131 ppm and 0.96 to 34.1 ppm, respectively. Average concentrations were 26.11 ppm in Ca and 8.10 ppm in Mg. In case of HCO$_3$, 24 to 295 ppm of concentration range and average of 63.13 ppm were obtained. Fe range was 0.01 to 0.87 ppm and its average was 0.14 ppm. This results showed that Fe elimination was necessary in well water.