• Natural Product Sciences
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• v.20 no.4
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• pp.243-250
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• 2014

A simple GC method with a FID detector was developed in order to determine two main compounds (${\beta}$-sitosterol and lupenone) for Adenophorae Radix. ${\beta}$-Sitosterol and lupenone were analyzed by the gradient thermal ramping method. Nitrogen was used as the carrier gas at 108 kPa. The flow rate of gas was 2.0 mL/min; $2{\mu}L$ of filtered sample was injected at a split ratio of 1 : 80. This method was fully validated with respect to linearity, precision, accuracy and robustness. Further, this GC-FID method was applied successfully in order to quantify two compounds in an Adenophorae Radix extract. The GC analytical method for classification analysis was performed by repeated analysis of 59 reference samples in order to differentiate between Adenophora triphylla var. japonica Hara and 14 Codonopsis lanceolata. The results indicate that the GC-FID method is suitable and reliable for the quality evaluation of Adenophorae Radix.

• Korean Journal of Food Science and Technology
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• v.28 no.2
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• pp.226-231
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• 1996

A serum-pulp method was applied to concentrate peach pulp with aroma recovery. The serum portion was concentrated to five-fold at $50{\sim}55^{\circ}C$ and $30{\sim}50$ mmHg with aroma recovery. The concentrated serum, insoluble pulp and aroma fraction were recombined to make a two-fold concentrated peach pulp. The results of GC and GC/MS analysis for volatile compounds and sensory evaluation of concentrated peach pulp indicated that flavor quality was significantly improved by addition of aroma fractions. A 10% aroma recovery appeared to be appropriate for peach pulp.

• Korean Journal of Veterinary Service
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• v.16 no.2
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• pp.103-110
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• 1993

The Aeromonas strains were isolated from diseased cultured catfsh (Silurus asotus) in the ponds near by Gochang of Chunbuk. The present isolates were identified as A. hydrophila based on their biological and biochemica1 characteristics. The isolates of A. hydrophila were named GC-1, GC-2, GC-3, GC-4 and GC-5, Five strains were grew optimally at temperatures $35^{\circ}C,$ pH 7.5 and in 0.5 to l% NaCl. This bacterium(GC-1) was injected into health catfish in order to prove the causative agent of ascites and haemorrhagic ulcers. The symptoms in cat fish infected by this challenge method were observed to be very similar to the symptoms of a natural infection, but controls did not show any abnormal symptoms during the experimental period. At 24 post-injection, the red spot developed around the injection site and the haemorrhagic ulcers was extended near the gill and ventral fin. Five strains were tested for drug sensitivity by plate method. All strains were sensitivity to gentamicin and resistant to penicillin, streptomycin and tetracycline.

• Journal of Marine Bioscience and Biotechnology
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• v.15 no.2
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• pp.96-102
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• 2023

Salicornia herbacea, a noted halophyte, has been widely researched for its diverse physiological activities. The continuous exploration of its compounds is essential. This study employed gas chromatography (GC) coupled with mass spectrometry (MS) for qualitative analysis. This involved pretreatment including trimethylsilyl (TMS) derivatization of the S. herbacea extract, facilitating its GC analysis. Five compounds, including various fatty acids and β-sitosterol, were identified by direct analysis of the methanol extract of S. herbacea without pretreatment by GC-MS. Conversely, the analysis of the TMS-derivatized extract revealed 28 distinct peaks. Quantitative analysis further indicated that the predominant compounds in the S. herbacea extract were sugars and sugar derivatives, notably glucose, fructose, and glucitol. The collective concentration of these sugars and its derivatives amounted to 116.45 mg/g, representing 11.6% of the dry weight of the raw S. herbacea. Following sugars and their derivatives, fatty acids constituted the next most abundant group of compounds. However, the presence of amino acids and organic acids was relatively low.

• Korean Journal of Remote Sensing
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• v.34 no.6_1
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• pp.1143-1153
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• 2018

For TOPS InSAR processing, high-precision image co-registration is required. We propose an image co-registration method suitable for the TOPS mode by comparing the performance of cross correlation method, the geometric co-registration and the enhanced spectral diversity (ESD) matching algorithm based on the spectral diversity (SD) on the Sentinel-1 TOPS mode image. Using 23 pairs of interferometric pairs generated from 25 Sentinel-1 TOPS images, we applied the cross correlation (CC), geometric correction with only orbit information (GC1), geometric correction combined with iterative cross-correlation (GC2, GC3, GC4), and ESD iteration (ESD_GC, ESD_1, ESD_2). The mean of co-registration errors in azimuth direction by cross correlation and geometric matching are 0.0041 pixels and 0.0016 pixels, respectively. Although the ESD method shows the most accurate result with the error of less than 0.0005 pixels, the error of geometric co-registration is reduced to 0.001 pixels by repetition through additional cross correlation matching between the reference and resampled slave image. The ESD method is not applicable when the coherence of the burst overlap areas is low. Therefore, the geometric co-registration method through iterative processing is a suitable alternative for time series analysis using multiple SAR data or generating interferogram with long time intervals.

• Korean Journal of Pharmacognosy
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• v.29 no.2
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• pp.129-135
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• 1998

Higenamine is known as a cardiotonic principle of Aconiti tuber. The analytical procedures were established for the detection of higenamine in plants. The amounts of higenamine in several Aconiti tubers and the embryo of Nelumbo nucifera, another plant species known to contain higenamine, were determined. The $H_2O$ soluble fraction prepared from MeOH extract was first treated with AD-2 resin and then applied to either HPLC or GC/MSD systems. With HPLC, $6.4{\sim}19.2\;{\mu}g/g$ of higenamine were detected from various Aconiti tubers and $182.3\;{\mu}g/g$ of higenamine from the embryo of Nelumbo nucifera. The results obtained with GC/MSD also provided comparable data with those obtained with HPLC.

• Korean Journal of Soil Science and Fertilizer
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• v.30 no.3
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• pp.295-300
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• 1997

Flavor components of natively grown tea plant(Camellia sinensis O. kuntze) in Korea, collected from 12 locations, were analyzed by gas chromatograph and mass spectrometer. Seventy to eighty flavor components in tea leaves were separated by GC. Total 52 flavor components were identified by comparing gas chromatograhp retention time and mass spectral date. They were classified as 19 alcohols, 5 aldehydes, 2 hydrocarbons, 6 ketones, 4 esters, 3 lactones, 2 acids, 3 phenols, 4 pyrazines, and 4 nitrogenous compounds. Major compounds identified were geraniol, linalool oxide, 1-hexanol and ethanol.

• Advances in Energy Research
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• v.3 no.2
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• pp.117-124
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• 2015

In this paper, we have reported an enhancement in thermoelectric properties of un-doped zinc oxide (ZnO) grown by molecular beam epitaxy (MBE) on silicon (001) substrate by annealing treatment. The grown ZnO thin films were annealed in oxygen environment at $500^{\circ}C-800^{\circ}C$, keeping a step of $100^{\circ}C$ for one hour. Room temperature Seekbeck measurements showed that Seebeck coefficient and power factor increased from 222 to $510{\mu}V/K$ and $8.8{\times}10^{-6}$ to $2.6{\times}10^{-4}Wm^{-1}K^{-2}$ as annealing temperature increased from 500 to $800^{\circ}C$ respectively. This observation was related with the improvement of crystal structure of grown films with annealing temperature. X-ray diffraction (XRD) results demonstrated that full width half maximum (FWHM) of ZnO (002) plane decreased and crystalline size increased as the annealing temperature increased. Photoluminescence study revealed that the intensity of band edge emission increased and defect emission decreased as annealing temperature increased because the density of oxygen vacancy related donor defects decreased with annealing temperature. This argument was further justified by the Hall measurements which showed a decreasing trend of carrier concentration with annealing temperature.

• Journal of Acupuncture Research
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• v.28 no.2
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• pp.89-95
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• 2011

Objectives : The purpose of this study was to investigate the composition of Rehmannia glutinosa's essential oils with Rehmanniae Radix herbal acupuncture Methods : I obtained the essential oils of Rehmannia Radix by hydrodistillation extraction method and supercritical fluid extraction(SFE) method, and then I analyzed those by GC/MS(gas chromatography/mass spectrum). Results : 1. With GC(gas chromatography) and GC/MS(gas chromatography/mass spectrum) analysis. I identified 9 compounds in the Rehmanniae Radix's essential oil obtained through the SFE method. The main compounds were as follows : Hexachloroethane(2.24%), N-Butyl-benzenesulfonamide(2.05%), hexadecanoic acid(1.93%), hexadecanoic acid, ethyl ester(3.49%), 9,12-Octadecadienoic acid(z,z)(2.70%), (9E)-9-Octadecenoic acid(6.14%), ethyl linoleate(4.43%), ethyl oleate(5.80%). 2. I failed to get Rehmanniae Radix's essential oil obtained through the hydrodistillation method. 3. With GC(gas chromatography) and GC/MS(gas chromatography/mass spectrum) analysis. I identified 4 compounds in the Rehmanniae Radix's essential oil obtained through the hydrodistillation method. The main compounds were as follows : Ethylbis(trimethylsilyl)amine(1.04%), 2-(Trimethylsiloxy)benzoic methyl ester(2.65%), Hexadecanoic acid trimethylsilyl ester(12.61%), octadecanoic acid, trimethylsilyl ester(6.28%). Conclusions : The substances by hydrodistillation method may not perfectly match with the substances by supercritical fluid extraction(SFE) method in essential oils extracted form Rehmanniae Radix. But, the main substances was assumed Hexadecanoic acid and octadecanoic acid.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.7 no.1
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• pp.17-23
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• 2009

Dihexyloctanamide(DHOA) was used as an extractant or phase modifier with the diamide extractants in a solvent extraction process for a radioactive liquid waste treatment. The degradation compounds of the DHOA extractant, irradiated with $^{60}Co$ gamma ray, were octanoic acid and dihexylamine which are identified by a Fourier transform infrared(FT-IR) and gas chromatograph/mass spectrometer(GC/MS) analysis, and determined by the GC/MS with selected ion monitoring(SIM) mode. Retention behavior of octanoic acid, tridecane (internal standard) and dihexylamine in total ion chromatogram (TIC) were 8.65 min., 9.79 min., and 10.27 min., respectively. With increasing the absorbed dose of the $\gamma$-ray irradiated DHOA, the concentration of octanoic acid was decreased and that of dihexylamine was increased.