• Journal of Korean Society for Atmospheric Environment
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• v.15 no.6
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• pp.713-725
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• 1999

Air pollutants($SO_2$, NOx, $O_3$ and aerosol number) were measured using an aircraft to investigate the characteristical features of long-range transport of sulfur compounds over the Yellow Sea for the periods of 26~27 April and 7~10 November in 1998. The mean $SO_2$ concentrations of April 26th~27th and November 7th~10th flight were 0.6~1.8 ppb and 0.5~8.3 ppb, respectively, and the sulfur transport was largely limited to the atmospheric boundary layer. Especially, $SO_2$ increased up to 8.3 ppb altogether with the increase of particle number concentraton especially on November 8, 1998. In addition, $O_3$ was remarkably decreased against the increase of $SO_2$and particle number concentrations. This enhanced $SO_2$ concentration occurred in the low level westerlies in association with the anticyclonic flow over Southern China and the cyclonic circulation over Manchuria. Aerosol analyses at Taean site also showed that sulfate concentration increased 2~3 times higher than those of another sampling days, which could suggest possible interactions between aerosol particels and tropospheric ozone. A rigorous evaluation will be possible after the more intensive measurements and quantitative analyses with detailed chemistry model including the postulated heterogeneous mechanism.

• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.2
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• pp.13-20
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• 2019

In this study, the ignition delay time of blended aviation fuels was measured and analyzed to confirm the characteristic of ignition delay according to the blending ratio of bio-aviation fuel to petroleum-based aviation fuel. The ignition delay time of bio-aviation fuel(Bio-6308) was shorter than that of petroleum-based aviation fuel(Jet A-1) at all measured temperatures; further, the ignition delay time of the blended aviation fuels shortened as the ratio of Bio-6308 increased. It was confirmed that the aromatic compounds constituting the Jet A-1 affect these results; this was done by comparing the obtained ignition delay time with that of n-heptane/Toluene.

• Food Science of Animal Resources
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• v.39 no.3
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• pp.355-370
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• 2019

The present study aimed at evaluating effects of traditional sauce type and storage time on shelf-life and flavor compounds of marinated pork cooked by Sous-Vide method. Five different traditional sauces (Meju soy sauce, Brewed soy sauce, Fish-soy sauce, Ishiru fish sauce and Anchovy fish sauce) purchased from Asian countries were used. After marination with the sauces, polyvinylchloride film bags containing the marinated pork samples were cooked using Sous-Vide method for $55^{\circ}C$ for 5 h and $60^{\circ}C$ for 30 min, and were then stored for 8 wk at $10^{\circ}C$. Results showed that the pork samples marinated with the sauces retarded the growth of total plate counts (TPC) during storage. At $8^{th}$ wk storage, TPC counts were significantly lower in all samples marinated with the sauces compared to control (p<0.05). Lipid oxidation level was significantly lower in the T2 (Meju soy sauce) and T6 (Anchovy fish sauce) compared to those of T3 (Brewed soy sauce) and T5 (Ishiru fish sauce) or control after 8 wk storage (p>0.05). Forty volatile flavor compounds were detected from the control and marinated samples at $4^{th}$ wk of storage. The pork marinated with Anchovy fish sauce presented significantly higher amounts of importantly pleasant flavor compounds such as; pyrazines and sulfurcontaining compounds than those marinated with other remaining sauces and control. It is concluded that the marination with Anchovy fish sauce partly improved the shelf-life and increased amounts of pleasant flavor compounds of Sous-Vide cooked pork products during storage in comparison to the other remaining sauces.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.08a
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• pp.75-75
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• 2020

Potatoes were first introduced outside the Andes region four centuries ago, and have become an integral part of much of the world's food. Potatoes were first introduced into Europe in the 16th century and Korea in the early 19th century. Potatoes have a short growing season, high production per unit area, relatively strong environmental adaptability, and are cultivated in more than 130 countries around the world. It is the world's fourth-largest crop, following rice, wheat, bean and maize. In the nutritional aspects, potatoes contain abundant vitamins and minerals, as well as an assortment of phytochemicals such as carotenoids and natural phenols. Due to the high content of potato functional compounds, it has known that potatoes are effective in the prevention of various human diseases. In particular, the potato contains a large amount of polar compounds, including the saponin in the polar compounds, and the physiological activity of the saponins, such as immunity enhancement, antioxidant and anti-inflammatory is known. In this study, the antioxidative activity of polar compounds from five potatoes was examined by cell based anti-oxidation assay. The smallest amount of ROS(Reactive oxygen species) was generated when the compound was derived from 'Haryung' and 'hongyoung' and strong SOD(Superoxide dismutase) activity was observed in 'Sumi' and 'Jayoung'. The results of this study reveal the antioxidative effect of polar compounds extracted from various kind of potatoes, which will enable the acquisition of new bioactive candidates and the establishment of new profit generation models for farmers

• Journal of the Korean Chemical Society
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• v.38 no.2
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• pp.108-121
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• 1994

The retention indices of branched-chain alkane, benzene ring, alcohol, amine, ketone, aldehyde and cyclic compounds were measured at 150, 180 and $210^{\circ}C$ on OV-1701 and OV-1 capillary columns. The group retention factors (GRF) of the substituents and the st` ructure retention factors (SRF) of the molecular structure change are derived from the retention indices of reference compounds and series of homologues. The $GRF_f$ equation of `f'th substituent is $GRF_f\;=\;I_{obs}-(100Z + \sum\limits_{i{\neq}f}GRF_i$ + {\sum}$SRF_i$)and the SRFf equation of `f'th molecular structure group is $SRF_f\;=\;I_{obs}-(100Z + {\sum}GRFi + \sum\limits_{i{\neq}f}SRF_i$). The predicted retention indices for those compound were in agreement, within the error of $\pm2$ and $\pm3%$, with the observed values that were obtained using the OV-1701 and OV-1 capillary column, respectively. The $\Delta$ xi of the substituents and $\Delta$ yi of the molecular structure change according to temperature change are derived from the $\Delta'/^{\circ}C$ of reference compounds and series of homologues. The $\Delta$ xi equation of the `f'th substituent is ${\Delta}x_f = {$\Delta}'/^{\circ}C+ \sum\limits_{i{\neq}f}\Delta$ xi + {\sum}{\Delta}yi\;and\;{\Delta}yi$ equation of the `f'th molecular structure group is ${\Delta}y_f$ = {\Delta}'/^{\circ}C+{\sum}{\Delta}xi +\sum\limits_{i{\neq}f}{\Delta}yi$. The predicted $\Delta'/^{\circ}C$ for these compounds were in agreement, within the error of ${\pm}18%$ and 17%, with the observed values that were obtained using the OV-1701 and OV-1 capillary column, respectively.

• Environmental Engineering Research
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• v.10 no.5
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• pp.227-238
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• 2005

The characteristics of nitrogen removal by the free cell and the immobilized cell of R. capsulatus were investigated. Denitrification by R. capsulatus cells resulted in reduction of ORP with the rapid depletion of DO and the increase of pH. Without accumulation of nitrite, the removal efficiencies of ${NO_3}^-$-N for the free cell and the immobilized cell were 99.1 and 99.3%, respectively. During the three-month experiment of goldfish breeding equipped with a water-purification biofilter, the average values of pH and total cell numbers present in an aquarium were not significantly different between water-purification system and the control. The average concentrations of ${NH_4}^+$-N and ${PO_4}^{2-}$-P in water-purification system were relatively low, compared to that in the control. Goldfish died at $11^{th}$, $16^{th}$, $43^{rd}$, and $67^{th}$ days in the control, while goldfish died at $10^{th}$, $20^{th}$, and $39^{th}$ days in the water-purification system. On the days of goldfish's death, the total concentrations of nitrogenous compounds except for ${NO_2}^--N$ were higher than those on the other days of the experiment, especially with the concentrations of ${NH_4}^+$-N ranging from 7.4 to 13.5 mg/L. The water-purification system also showed the less turbidity of water with more active movement of goldfish than the control. PVA gel beads showed almost the full denitrifying ability even after the long-term experiment. As a result, the water-purification system was effective to remove nitrogenous compounds with better survival of goldfish.

• Korean Journal of Pharmacognosy
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• v.46 no.2
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• pp.160-166
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• 2015

Yijung-tang (YJT) is a traditional herbal formula comprising 4 medicinal herbs. In the present study, we performed the simultaneous analysis for three compounds of YJT and examined anti-allergic effects in vitro. The column for separation of three compounds was used Gemini C18 column and maintained at 40$^{\circ}C$. The mobile phase for gradient elution consisted of two solvent systems. To evaluate Th2 chemokines, YJT was treated into tumor necrosis factor (TNF)-${\alpha}$ and interferon (IFN)-${\gamma}$-stimulated HaCaT cells, and performed ELISA for thymus and activation regulated chemokine (TARC) and regulated on activation, normal T-cell expressed and secreted (RANTES). To measure Th2 cytokines, YJT was added into primary mouse splenocytes, and performed ELISA for interleukin (IL)-4, 5, 13. Calibration curves were acquired with r² >0.9999. The contents of liquiritin, glycyrrhizin, and 6-gingerol in YJT were 4.50 mg/g, 11.10 mg/g, and 1.33 mg/g, respectively. YJT inhibited production of TARC and RANTES in TNF-${\alpha}$ and IFN-${\gamma}$-treated HaCaT cells. YJT also reduced production of IL-4, 5, and 13 in primary mouse splenocytes. In conclusion, our data will be a valuable information to improve quality control and anti-allergic effects of YJT.

• Nuclear Engineering and Technology
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• v.51 no.5
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• pp.1373-1380
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• 2019

Besides promising implications as fertile nuclear materials, thorium carbonitrides are of great interest owing to their peculiar physical and chemical properties, such as high density, high melting point, good thermal conductivity. This paper reports first-principles simulation results on the structural, electronic and magnetic properties of cubic thorium carbonitrides $ThC_xN_{(1-x)}$ (X = 0.03125, 0.0625, 0.09375, 0.125, 0.15625) employing formalism of density-functional-theory. For the simulation of physical properties, we incorporated full-potential linearized augmented plane-wave (FPLAPW) method while the exchange-correlation potential terms in Kohn-Sham Equation (KSE) are treated within Generalized-Gradient-Approximation (GGA) in conjunction with Perdew-Bruke-Ernzerhof (PBE) correction. The structural parameters were calculated by fitting total energy into the Murnaghan's equation of state. The lattice constants, bulk moduli, total energy, electronic band structure and spin magnetic moments of the compounds show dependence on the C/N concentration ratio. The electronic and magnetic properties have revealed non-magnetic but metallic character of the compounds. The main contribution to density of states at the Fermi level stems from the comparable spectral intensity of Th (6d+5f) and (C+N) 2p states. In comparison with spin magnetic moments of ThSb and ThBi calculated earlier with LDA+U approach, we observed an enhancement in the spin magnetic moments after carbon-doping into ThN monopnictide.

• Environmental Analysis Health and Toxicology
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• v.13 no.3_4
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• pp.95-104
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• 1998

INTRODUCTION : Arsenic is a ubiquitous element present in various compounds throughout the earth's crust. The use of arsenic compounds increased greatly during the 18th and 19th centuries, including its use in pigments and dyes, as a preservative of animal hides, in glass manufacture, agricultural pesticides, and various pharmaceutical substances. The causal association between human arsenic exposure, usually in the form of inorganic compounds containing trivalent arsenite (As$^{III}$) or pentavalent arsenate (As$^V$), and various forms of human cancer has been known for many years.

• Applied Biological Chemistry
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• v.2
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• pp.29-35
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• 1961

The daily variation in the total quantity of flavin compounds (FAD, FMN, FR) in greenbean during its germination were measured by Yagi's methods. The results obtained were as follow. 1. The total quantity of flavin compounds of the greenbean sprouts was increased with growth of sprouts until the 8th days. After this period its contents were decreased slightly. 2. The flavin compounds of greenbean sprouts were comfirmed to be synthesized as free riboflavin during its germination. 3. FAD was the major pat of total flavin compounds in cotyledon but there was significant variation in the contents of FAD, FMN and FR in hypocotyl.