• The Journal of the Petrological Society of Korea
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• v.18 no.1
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• pp.31-47
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• 2009

We performed petrological, geochemical, and geochronological study for the Pyeonghae granite gneiss and the Hada leuco-granite gneiss intruding the Paleoproterozoic meta-sedimentary rocks (pyeonghae formation and Wonnam formation) of the Pyeonghae area located in northeastem part of the Yeongnam (Sobaeksan) massif. The Pyeonghae granite gneiss generally has higher abundance of mafic minerals (biotite etc.), and posesses higher ${Fe_2}{O_3}^t$, MgO, CaO, $TiO_2$, $P_{2}O_{5}$ contents but lower $SiO_2$ and $K_{2}O$ contents than the Hada leuco-granite gneiss which tends to have slightly high $Al_{2}O_{3}$ and $Na_{2}O$ contents and slightly high larger negative Eu anomalies. However both gneisses reveal very similar REE concentrations and chondrite-normalized patterns and apparently show differentiation trend affected by crystallization of biotite, plagioclase, apatite and sphene. Their peraluminous and calc-alkaline chemistry suggests tectonic environment of volcanic arc. SHRIMP Zircon U-Pb age determinations yield upper intercept ages of $1990{\pm}23\;Ma$ ($2{\sigma}$) and $1939{\pm}41\;Ma$ ($2{\sigma}$), and weighted mean $^{207}Pb/^{206}Pb$ ages of $1982{\pm}6.3\;Ma$ ($2{\sigma}$) and $1959{\pm}28\;Ma$ ($2{\sigma}$) for the Pyeonghae granite gneiss and the Hada leuco-granite gneiss respectively, showing overlapping ages within the error. Our study suggests that the Precambrian granitoids in this area intruded contemporaneously with the Buncheon granite gneissin volcanic arc environment.

• Journal of The Korean Society of Grassland and Forage Science
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• v.32 no.3
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• pp.301-308
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• 2012

Near infrared reflectance spectroscopy (NIRS) has become increasingly used as a rapid and accurate method of evaluating some chemical compositions in forages. This study was carried out to explore the accuracy of near infrared spectroscopy (NIRS) for the prediction of chemical parameters of Italian ryegrass silages. A population of 267 Italian ryegrass silages representing a wide range in chemical parameters and fermentative characteristics was used in this investigation. Samples of silage were scanned at 2 nm intervals over the wavelength range 680~2,500 nm and the optical data recorded as log 1/Reflectance (log 1/R) and scanned in intact fresh condition. The spectral data were regressed against a range of chemical parameters using partial least squares (PLS) multivariate analysis in conjunction with spectral math treatments to reduced the effect of extraneous noise. The optimum calibrations were selected on the basis of the highest coefficients of determination in cross validation ($R^2$) and the lowest standard error of cross validation (SECV). The results of this study showed that NIRS predicted the chemical parameters with very high degree of accuracy. The $R^2$ and SECV were 0.98 (SECV 1.27%) for moisture, 0.88 (SECV 1.26%) for ADF, 0.84 (SECV 2.0%), 0.93 (SECV 0.96%) for CP and 0.78 (SECV 0.56), 0.81 (SECV 0.31%), 0.88 (SECV 1.26%) and 0.82 (SECV 4.46) for pH, lactic acid, TDN and RFV on a dry matter (%), respectively. Results of this experiment showed the possibility of NIRS method to predict the chemical composition and fermentation quality of Italian ryegrass silages as routine analysis method in feeding value evaluation and for farmer advice.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.9
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• pp.1419-1425
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• 2013

The aim of this study was to investigate the method validation for the determination of eleutherosides (B and E) and ${\beta}$-glucan in Acanthopanax (A.) koreanum. This medicinal plant reportedly mainly included eleutherosides which exhibit the pharmacological effects, and ${\beta}$-glucan substantially enhances the function of the immune system by activating macrophages. The specificity, linearity, precision, accuracy, limit of detection (LOD, S/N=3), and limit of quantification (LOQ, S/N=10) were measured by HPLC and enzymatic methods. Our results showed that the coefficient of calibration correlation ($R^2$) for eleutheroside B and E were 0.9997 and 0.9999, respectively. The limits of detection (LOD) for eleutheroside B and E were $0.050{\mu}g/mL$ and $0.025{\mu}g/mL$, respectively. The recovery rate of eleutheroside B and E were revealed in the high range of 100.66~110.04% and 94.26~111.62%, respectively. The inter-day precision of eleutheroside B and E in the root and stem in A. koreanum were 1.4~5.0% and 1.1~2.5%, respectively. The intra-day precision of eleutheroside B and E in the root and stem in A. koreanum were 2.8~2.9% and 0.4~1.1%, respectively. Furthermore, the inter-day and intra-day precision of ${\beta}$-glucan in the stem, leaf, and fruit of A. koreanum were 1.32~5.67% and 8.01~11.76%, respectively. In conclusion, the methods were validated for the detection of eleutherosides and ${\beta}$-glucan in A. koreanum.

• The Korean Journal of Pesticide Science
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• v.19 no.1
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• pp.5-13
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• 2015

A chromatographic method for the determination of imazapyr, a non-selective herbicide, in agricultural commodities was developed to use safety control of pesticide residue on crops, and was fully validated as an official method for residue analysis. Agricultural commodities, mandarin (fruit), hulled rice (cereal grains), pepper (vegetables), potato (potatoes) and soybean (beans) were extracted with methanol and partitioned with dichloromethane to remove the interference obtained from sample extracts, adjusting pH to 2.5 by 4N hydrochloric acid. Finally, they were analyzed by high performance liquid chromatography coupled to UV detector (HPLC-UVD). The developed method had the linearity in the range of test concentrations with coefficients of determination ($r^2$) more than 0.99. Recovery studies were carried out at three concentration levels (LOQ, 10LOQ, and 50LOQ) performing five replicates at each level. Recoveries were ranged between 72.1 to 108.0%, with relative standard deviations less than 10%. A consistent recovery was determined according to the CODEX guidelines (CAC/GL40, 2003). Finally, LC/MS with selected ion monitoring was also applied to confirm the suspected residues of imazapyr in agricultural samples. This developed method for determination of imazapyr residues in agricultural commodities. can be used as an official method.

• Journal of The Korean Society of Grassland and Forage Science
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• v.36 no.1
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• pp.50-57
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• 2016

This study was conducted to determine the effect of mathematical transformation on near infrared spectroscopy (NIRS) calibrations for the prediction of chemical composition and fermentation parameters in corn silage. Corn silage samples (n=407) were collected from cattle farms and feed companies in Korea between 2014 and 2015. Samples of silage were scanned at 1 nm intervals over the wavelength range of 680~2,500 nm. The optical data were recorded as log 1/Reflectance (log 1/R) and scanned in intact fresh condition. The spectral data were regressed against a range of chemical parameters using partial least squares (PLS) multivariate analysis in conjunction with several spectral math treatments to reduce the effect of extraneous noise. The optimum calibrations were selected based on the highest coefficients of determination in cross validation ($R^2{_{cv}}$) and the lowest standard error of cross validation (SECV). Results of this study revealed that the NIRS method could be used to predict chemical constituents accurately (correlation coefficient of cross validation, $R^2{_{cv}}$, ranging from 0.77 to 0.91). The best mathematical treatment for moisture and crude protein (CP) was first-order derivatives (1, 16, 16, and 1, 4, 4), whereas the best mathematical treatment for neutral detergent fiber (NDF) and acid detergent fiber (ADF) was 2, 16, 16. The calibration models for fermentation parameters had lower predictive accuracy than chemical constituents. However, pH and lactic acids were predicted with considerable accuracy ($R^2{_{cv}}$ 0.74 to 0.77). The best mathematical treatment for them was 1, 8, 8 and 2, 16, 16, respectively. Results of this experiment demonstrate that it is possible to use NIRS method to predict the chemical composition and fermentation quality of fresh corn silages as a routine analysis method for feeding value evaluation to give advice to farmers.

• Korean Journal of Remote Sensing
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• v.26 no.2
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• pp.251-262
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• 2010

In order to provide quantitative control of the standard products of Geostationary Ocean Color Imager (GOCI), on-board radiometric correction, atmospheric correction, and bio-optical algorithm are obtained continuously by comprehensive and consistent calibration and validation procedures. The calibration/validation for radiometric, atmospheric, and bio-optical data of GOCI uses temperature, salinity, ocean optics, fluorescence, and turbidity data sets from buoy and platform systems, and periodic oceanic environmental data. For calibration and validation of GOCI, we compared radiometric data between in-situ measurement and HyperSAS data installed in the Ieodo ocean research station, and between HyperSAS and SeaWiFS radiance. HyperSAS data were slightly different in in-situ radiance and irradiance, but they did not have spectral shift in absorption bands. Although all radiance bands measured between HyperSAS and SeaWiFS had an average 25% error, the 11% absolute error was relatively lower when atmospheric correction bands were omitted. This error is related to the SeaWiFS standard atmospheric correction process. We have to consider and improve this error rate for calibration and validation of GOCI. A reference target site around Dokdo Island was used for studying calibration and validation of GOCI. In-situ ocean- and bio-optical data were collected during August and October, 2009. Reflectance spectra around Dokdo Island showed optical characteristic of Case-1 Water. Absorption spectra of chlorophyll, suspended matter, and dissolved organic matter also showed their spectral characteristics. MODIS Aqua-derived chlorophyll-a concentration was well correlated with in-situ fluorometer value, which installed in Dokdo buoy. As we strive to solv the problems of radiometric, atmospheric, and bio-optical correction, it is important to be able to progress and improve the future quality of calibration and validation of GOCI.

• Clean Technology
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• v.25 no.2
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• pp.107-113
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• 2019

Numerical model that considered the shrinking core model and elutriation and degradation of particles was developed to predict selective chlorination of ilmenite and carbo-chlorination of $TiO_2$ in a two stage fluidized bed chlorination furnace. It is possible to analyze the fluidized bed chlorination reaction to be able to reflect particle distribution for mass balances and the chlorination reaction. The numerical model showed an accuracy with error less than 6% compared with fluidized bed experiments. The chlorination degree with particle size change was greater with a smaller particle size, and there was a 100 min difference to obtain a chlorination degree of 1 between $75{\mu}m$ and $275{\mu}m$. This was not shown to such a great extent with variation of temperature ($800{\sim}1000^{\circ}C$), and there was only a 10 min difference to obtain a chlorination degree of 0.9. In the first selective chlorination process, the mass reduction rate approached to the theoretical value of 0.4735 after 180 min, and chlorination changed the Fe component into $FeCl_2$ or $FeCl_3$ and showed nearly 1. In the second carbo-chlorination process, the chlorination degree of $TiO_2$ approached 0.98 and the mass fraction reached 0.02 with conversion into $TiCl_4$. In the first selective chlorination process, 98% of $TiO_2$ was produced at 180 min, and this was changed into 99% of $TiCl_4$ after an additional 90 min. Also the mass reduction rate of $TiO_2$ was reduced to 99% in the second continuous carbo-chlorination process.

• Journal of Applied Biological Chemistry
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• v.64 no.2
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• pp.113-119
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• 2021

Olive (Olea europaea L.) leaves, a raw material for health functional foods and cosmetics have abundant polyphenols including oleuropein (major bioactive compound) with various biological activities: antioxidant, antibacterial, antiviral, anticancer activity, and inhibit platelet activation. Oleuropein has been reported as skin protectant, antioxidant, anti-ageing, anti-cancer, anti-inflammation, anti-atherogenic, anti-viral, and anti-microbial activity. Despite oleuropein is the important compound in olive leaves, there is still no quantitative approach to reveal oleuropein content in commercial products. Therefore, a validated method of analysis has to develop for oleuropein. In this study, the components and oleuropein content in 10 types of products were analyzed using a developed method with ultra-performance liquid chromatography to quadrupole time-of-flight mass spectrometry, charge of aerosol detector, and photodiode array. The total of 18 compounds including iridoids (1, 3, 4, 14, and 16-18), coumarin (2), phenylethanoids (5, 9, and 11), flavonoids (6-8, 10, 12, and 13), lignan (15), were tentatively identified in the leaves extract based high resolution mass spectrometry data, and the content of oleuropein in each product was almost identical between two detection methods. The oleuropein in three commercial product (A, G, H) was contained more over the suggested content, and it of five products (B, E, H, I, J) were analyzed within 5-10% error range. However, the two products (C, D) were found far lower than suggested contents. This study provides that analytical results of oleuropein could be a potential information for the quality control of leaf extract for a manufactured functional food.