• Analytical Science and Technology
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• v.24 no.6
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• pp.421-428
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• 2011

In this study, headspace disk type monolithic material sorptive extraction (HS-MMSE) was developed, validated and applied to the analysis of volatile aroma compounds from vanilla perfume by gas chromatography -mass spectrometry (GC/MS). HS-MMSE uses monolithic material (MonoTrap) based on silica bonded with octadecyl silane (ODS) and activated carbon as a sorbent. Aroma compounds was adsorbed onto the MonoTrap in headspace and extracted by only 100 ${\mu}L$ of solvent. Total 12 volatile compounds from vanilla perfume were successfully analyzed using HS-MMSE. The influence of extractive parameters was investigated and optimized, using benzyl acetate, linalyl acetate, vanillin, ethyl vanillin as target compounds. Under the optimum condition, the limit of detection (S/N = 3) and the limit of quantification (S/N = 10) of proposed method for the target compounds were obtained within the range of 8.35~13.76 ng and 27.82~45.88 ng, respectively. The method showed good linearity with correlation coefficient more than 0.9888, satisfactory recovery and reproducibility. These results showed that HS-MMSE using disk type MonoTrap is a new promising technique for the analysis of volatile aroma compounds from vanilla perfume.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.42 no.1
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• pp.1-10
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• 2006

Present study was conducted to improve the spring frame net trap for conger eel, Conger myriaster which prevents by-catch and protects immature fish. A series of comparative fishing experiment was carried out in water off the south-east coast of Korea from Nov. 2004 to Jul. 2005. And analyzed the amount of catch, by-catch rate, and CPUE, etc. of experimental traps which were the spring frame net traps, sorted four types of flappers. And the compared gear was a plastic conger eel pot. The conclusions were as follows. By-catch rates of spring frame net trap with the compressed flapper bound by nylon mono-filament was about 0-3%. CPUE of spring frame net trap with the compressed flapper was about 50-60% lower than that of traditional and plastic pot. And in case of conger eel that the total length is over 350mm, CPUE was little different on each type of flapper of every mesh size.

• Journal of Dairy Science and Biotechnology
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• v.15 no.1
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• pp.1-9
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• 1997

This study was conducted to efficiently separate the Ig from Korean native cattle colostrum and to utilize them as an immunogen for the production of antibodies aginst rabbit. The results obtained were as follows : 1. About 84% of Ig G could be separated from Korean native cattle colostrum by·gel filtration using Superose 12 column on HPLC. The separation profile of Korean native cattle colostral immunoglobulin was similar that of Holstein colostral Ig. 2. Separation of Korean native cattle colostral Ig by anion exchange chromatography using Mono Q column on HPLC was poor resolution chromatographic pattern. 3. Hi-Trap Protein G column showed better results than the Protein A Sepharose CL-4B column in the Ig G binding capacity from Korean native cattle colostral Ig. 4. Protein G Sepharose Fast Flow system resulted in higher Ig g binding capacity as the industrial size scale-up approach. 5. Sufficient titer reaction of antibody to Korean native cattle colostral Ig G was confirmed by ELISA.

• Journal of Life Science
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• v.21 no.3
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• pp.464-467
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• 2011

Quercetin is a major flavonoid present in onions, which acts as an antioxidant. Quercetin exists both as a free compound and conjugated with carbohydrates, primarily as glucosides in onion. Aged black onion was made through a 30 day aging process in which the onions were kept in an environment of $60^{\circ}C$ and high humidity (90% RH). Quercetin and quercetin glucosides were assayed in onion bulbs before and after the aging process, using high performance liquid chromatography-electrospray ion trap mass spectrometry (HPLC-ESI/MS/MS). Quercetin mono- and diglucosides were identified in fresh onion bulbs, whereas quercetin aglycone was the only form present in aged black onion bulbs. These findings indicate that the quercetin mono- and di-glucosides present in fresh onions undergo complete deglycosylation during the aging process. Such profiling will provide a rapid method that can be used to assess changes in the two major quercetin glycosides during the aging process of onion bulbs.

• Bulletin of the Korean Chemical Society
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• v.32 no.12
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• pp.4275-4280
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• 2011

Present study describes the optimization of disk type sorptive extraction using monolithic material (Mono Trap) for the analysis of volatile aroma compounds from Lantana camara L. in combination with gas chromatography/mass spectrometry (GC/MS). Monolithic material sorptive extraction (MMSE) is a new sampling technique using a monolithic hybrid adsorptive disk (O.D. 10 mm, 1 mm thickness) made of high purity silica and activated carbon having a large surface area chemically bonded with octadecyl silane (ODS). The experimental parameters that may influence the MMSE efficiency have been optimized. Linearity, accuracy, precision and detection limits were evaluated to assess the performance of the proposed method. The method was validated with real plant samples of Lantana camara L. Twenty eight compounds including the main representative compounds of ${\alpha}$-curcumene and ${\beta}$-caryophyllene were found in analyzed samples. Results proved that proposed method could be used as a good alternative for the analysis for such volatile aroma compounds in plant samples.

• Journal of the Korean Society of Tobacco Science
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• v.20 no.1
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• pp.115-123
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• 1998

The semi-volatile fraction of cigarette mainstream smoke contains the most important aroma and taste that enhance smoke flavor. The components in mainstream smoke were analysed for commercially available cigarettes. To compare the semi-volatile components delivered from mainstream smoke of domestic cigarette with imported cigarette, we analyzed three types of filter cigarettes such as cellulose acetate mono filter, carbon dual filter and slim filter cigarette. Mainstream smoke was collected with a combination of Cambridge filter pad and liquid trap containing a small amount of acetone cooled by dry ice-methanol. We have identified 43 components from mainstream smoke by GC and GC/MS and found that benzene, toluene, 4-hydroxy-4-methyl-2-pentanone, 5-methyl-2-furaldehyde, acetic acids nicotine and triacetin were the main peaks in mainstream smoke. Also we have compared the relative amounts of semi-volatile compounds delivered from the domestic and imported cigarettes with three different filters. From the results of this study, the relative amounts of limonene, acetic acid, 5-methyl-Lfuraldehyde delivered from the imported cigarettes were generally higher than those of the domestic one's.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.340-340
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• 2012

최근 MOS 소자들이 게이트 산화막을 Mono-layer가 아닌 Multi-Layer을 사용하는 추세이다. Bulk와 High-k물질간의 Dangling Bond를 줄이기 위해 Passivation 층을 만드는 것을 예로 들 수 있다. 이러한 Double Layer의 쓰임이 많아지면서 계면에서의 Interface State Density의 영향도 커지게 되면서 이를 측정하는 방법에 대한 연구가 활발히 진행되고 있다. 본 연구에서는 $SiO_2$ Double Layer의 Interface State Density를 Conductance Method를 사용하여 구하는 연구를 진행하였다. Wet Oxidation과 Chemical Vapor Deposition (CVD) 공정을 이용하여 $SiO_2$ Double-layer로 증착한 후 Aluminium을 전극으로 하는 MOS-Cap 구조를 만들었다. 마지막 공정은 $450^{\circ}C$에서 30분 동안 Forming-Gas Annealing (FGA) 공정을 진행하였다. LCR meter를 이용하여 high frequency C-V를 측정한 후 North Carolina State University California Virtual Campus (NCSU CVC) 프로그램을 이용하여 Flatband Voltage를 구한 후에 Conductance Method를 측정하여 Dit를 측정하였다. 본 연구 결과 Double layer (Wet/CVD $SiO_2$)에 대해서 Conductance Method를 방법을 이용하여 Dit를 측정하는 것이 유효하다는 것을 확인 할 수 있었다. 본 실험은 앞으로 많이 쓰이고 측정될 Double layer (Wet/CVD $SiO_2$)에 대한 Interface State Density의 측정과 분석에 대한 방향을 제시하는데 도움이 될 것이라 판단된다.

• Korean journal of applied entomology
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• v.57 no.4
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• pp.415-423
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• 2018

Aphid is a typical vector that transfers various kinds of viruses to potatoes. Therefore, it is very important to control aphids moving into potato fields. We investigated the seasonal movement pattern of aphids and its virus transmission rates mainly in the three seed potato production regions at highland in Gangwon-do, Korea. In addition, we identified the aphid species with over-wintering eggs collected from barks or twigs of total 57 tree species around potato fields in winter season. The peak time of summer and winter migration of aphid was at the mid-June and the early October, respectively. A 2.8% of total aphid trapped in yellow water-pan trap was turned out PLRV-borne, and the virus transmission rate was 15.4% by Myzus persicae and 9.1% by Macrosiphum euphorbiae. PLRV-borne aphids started to flow in from the late May, and virus transmission rate of aphid trapped in mid-June was the highest with 10.4%. Totally 14 species of aphid eggs wintered in the 17 species of trees including Acer pictum subsp. mono and Acer pseudosieboldianum at the 11 sites. In particular, because it is not certain that Betula platyphylla var. japonica and Yamatocallis hirayamae do transmit potato virus, but they over-wintered in host plants distributed over a wide area, further research on transmission ability is necessary.