• Journal of Microbiology and Biotechnology
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• 제15권2호
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• pp.337-345
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• 2005

The degradation of phenanthrene, a model PAH compound, by microorganisms either in the mixed culture or individual strain, isolated from oil-contaminated soil in oil refmery vicinity sites, was examined. The effects of pH, temperature, initial concentration of phenanthrene, and the addition of carbon sources on biodegradation potential were also investigated. Results showed that soil samples collected from four oil refinery sites in Korea had different degrees of PAH contamination and different indigenous phenanthrene-degrading microorganisms. The optimal conditions for phenanthrene biodegradation were determined to be 30$^{circ}C$ and pH 7.0. A significantly positive relationship was observed between the microbial growth and the rate of phenanthrene degradation. However, the phenanthrene biodegradation capability of the mixed culture was not related to the degree of PAH contamination in soil. In low phenanthrene concentration, the growth and biodegradation rates of the mixed cultures did not increase over those of the individual strain, especially IC10. High concentration of phenanthrene inhibited the growth of microbial strains and biodegradation of phenanthrene, but was less inhibitory on the mixed culture. Finally, when non-ionic surfactants such as Brij 30 and Brij 35 were present at the level above critical micelle concentrations (CMCs), phenanthrene degradation was completely inhibited and delayed by the addition of Triton X100 and Triton N101.

• Korean Chemical Engineering Research
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• 제53권2호
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• pp.216-223
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• 2015

The present work explores the potential of wet air oxidation (WAO) for pretreatment of mixed lignocellulosic biomass to enhance enzymatic convertibility. Rice husk and wheat straw mixture (1:1 mass ratio) was used as a model mixed lignocellulosic biomass. Post-WAO treatment, cellulose recovery in the solid fraction was in the range of 86% to 99%, accompanied by a significant increase in enzymatic hydrolysis of cellulose present in the solid fraction. The highest enzymatic conversion efficiency, 63% (by weight), was achieved for the mixed biomass pretreated at $195^{\circ}C$, 5 bar, 10 minutes compared to only 19% in the untreated biomass. The pretreatment under the aforesaid condition also facilitated 52% lignin removal and 67% hemicellulose solubilization. A statistical design of experiments on WAO process conditions was conducted to understand the effect of process parameters on pretreatment, and the predicted responses were found to be in close agreement with the experimental data. Enzymatic hydrolysis experiments with WAO liquid fraction as diluent showed favorable results with sugar enhancement up to $10.4gL^{-1}$.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2003년도 춘계 학술발표대회
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• pp.102-102
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• 2003

The present study has been undertaken to characterize availability of camellia(Camellia japonica L.) as a medicinal plant with antineoplastic and chemosensitizing activities. The crude extracts from fresn camellia flower, young leaves and nutraceutical tea of camellia leaf and flower buds were evaluated on their potential activities against various human cancer cells and multidrug resistance to cancer cells in vitro. The range of cytotoxicity displayed from 120$\mu\textrm{g}$/mL to 200$\mu\textrm{g}$/mL. Catemix 1(CT-1) mixed with camellia and green tea showed high toxicity(respectively IC$\sub$50/=l16$\mu\textrm{g}$/mL, 129$\mu\textrm{g}$/mL) against AML-2/WT, acute myelogenous leukemia cell and MCF-7, brest adenocarcinoma pleual effusion cell. Generally camellia tea mixed with green tea showed higher cytotoxicity than the other camellia teas mixed with some herbs(CH). Methanol extract of steamed camellia tea and roasted camellia tea had a chemosensitizing effect to reverse Pgp-mediated MDR. In addition, camellia flower tea of insignificant cytotoxicity, chemosensitizing effect were increased remarkably chemosensitizing effect in mixed flower tea with some herbs.

• 한국전기전자재료학회논문지
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• 제31권1호
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• pp.29-33
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• 2018

Using a vanadium dioxide ($VO_2$) source, highly pure and amorphous vanadium oxide (VO) thin films were deposited using an e-beam evaporator at room temperature and high vacuum (<$10^{-7}$ Torr). Then, by controlling the post-annealing conditions such as $N_2:O_2$ pressure ratio and annealing time, we could easily synthesize a homogeneous $VO_2$ thin film and also mixed-phase VO thin films, including $VO_2$, $V_2O_5$, $V_3O_7$, $V_5O_9$, and $V_6O_{13}$. The crystallinity and phase of these were characterized by X-ray diffraction, and the surface morphology by FE-SEM. Moreover, the electrical properties and ethanol sensing measurements of the VO thin films were analyzed as a function of temperature. In general, mixed-phases as a self-doping effect have enhanced electrical properties, with a high carrier density and an enhanced response to ethanol. In summary, we developed an easy, scalable, and reproducible fabrication process for VO thin films that is a promising candidate for many potential electrical and optical applications.

• Journal of Preventive Veterinary Medicine
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• 제42권4호
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• pp.143-147
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• 2018

The present study aimed to develop growth prediction models of Listeria monocytogenes in processed meat products, such as mixed pressed hams, to perform accurate microbial risk assessments. Considering cold storage temperatures and the amount of time in the stages of consumption after opening, the growth of L. monocytogenes was determined as a function of temperature at 0, 5, 10, and $15^{\circ}C$, and time at 0, 1, 3, 6, 8, 10, 15, 20, 25, and 30 days. Based on the results of these measurements, a Baranyi model using the primary model was developed. The input parameters of the Baranyi equation in the variable temperature for polynomial regression as a secondary model were developed: $SGR=0.1715+0.0199T+0.0012T^2$, $LT=5.5730-0.3215T+0.0051T^2$ with $R^2$ values 0.9972 and 0.9772, respectively. The RMSE (Root mean squared error), $B_f$ (bias factor), and $A_f$ (accuracy factor) on the growth prediction model were determined to be 0.30, 0.72, and 1.50 in SGR (specific growth rate), and 0.10, 0.84, and 1.35 in LT (lag time), respectively. Therefore, the model developed in this study can be used to determine microorganism growth in the stages of consumption of mixed pressed hams and has potential in microbial risk assessments (MRAs).

• Asian-Australasian Journal of Animal Sciences
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• 제14권5호
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• pp.733-745
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• 2001

This review paper discusses the relevance and potential importance of food-feed systems in Asian agricultural systems, and in particular the role and contribution of legumes to these systems. A food-feed system is one that maintains, if not increases, the yield of food crops, sustains soil fertility, and provides dietary nutrients for animals. It involves a cropping pattern within which the feed crop has many beneficial effects without competing for land, soil nutrients and water with the food crops. The agricultural environment is described with reference to the priority agro-ecological zones and prevailing mixed farming systems in Asia. Within these systems, animal production is severely hampered by critical feed shortages which can however, be alleviated by the integration of suitable leguminous forages into the cropping systems. The review also focuses on the role and potential importance of leguminous forages in terms of biodiversity, their uses in farming systems, beneficial effects on animal performance, and draws attention to six case studies in different countries that clearly demonstrate many benefits of developing such food-feed systems. Considerable opportunities exist for widening the use of forage legumes in the development of systems with several complementary advantages (e.g. fenceline, cover crops, fodder banks, forage source and erosion control) to improve the development of sustainable crop-animal systems in Asia.

• 대한화학회지
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• 제28권2호
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• pp.86-94
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• 1984

${\beta}-Ag_3SI$의 단결정을 만들어 막전극으로의 응용을 살펴보았다. 그 결과 할로겐 이온들에 대해 감응함을 알았고, 분리용액법과 혼합용액법으로 할로겐 이온들에 대한 선택계수를 얻어 이론값과 비교검토 하였으며, 전위시간 곡선으로 부터 이 전극이 유리 전극기구에 의해 전도함을 알았고, 넓은 pH 범위에서 전위가 일정한 값을 가짐을 알았다. 한편 분석화학에의 응용을 살펴 본 결과 할로겐이온의 혼합용액에서 좋은 지시전극으로 사용할 수 있음을 알았다

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.653-655
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• 2005

More than 70 percent of terrestrial territory of Korea is mountainous areas where degradation becomes serious year by year due to illegal tombs, expanding golf courses and stone mine development. We elaborate the potential usage of high resolution image for the monitoring of the phenomena. We made the classification of tombs and the statistical radiometric characteristics of graves were identified from this project. The graves could be classified to 4 groups from the field survey. As compared with grouping data after clustering and discriminant analysis, the two results coincided with each other. Object-oriented classification algorithm for feature extraction was theoretically researched in this project. And we did a pilot project, which was performed with mixed methods. That is, the conventional methods such as unsupervised and supervised classification were mixed up with the new method for feature extraction, object-oriented classification method. This methodology showed about $60\%$ classification accuracy for extracting tombs from satellite imagery. The extraction of tombs' geographical coordinates and graves themselves from satellite image was performed in this project. The stone mines and golf courses are extracted by NDVI and GVI. The accuracy of classification was around 89 percent. The location accuracy showed extraction of tombs from one-meter resolution image is cheaper and quicker way than GPS method. Finally we interviewed local government officers and made analyses on the current situation of mountainous area management and potential usage of KOMPSAT-II images. Based on the requirement analysis, we developed software, which is to management and monitoring system for mountainous area for local government.

• 한국항행학회논문지
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• 제7권2호
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• pp.180-190
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• 2003

실수축 상의 적분 방법에 의한 정확한 closed-form 그린함수를 이용하여 코플래너 도파로의 불연속에 대한 공간영역 full-wave 해석을 하였다. MPIE(Mixed Potential Integral Equation)를 풀기 위한 수치계산 방법으로는 삼각형 요소를 이용한 갤러킨 방법을 사용하였다. 경계면에서 삼각형 요소상의 기저함수로는 선형함수를 사용하였으며, 관측점과 전원점이 일치하는 특이점 근방의 적분 계산을 위해 면적분을 선적분 형태로 바꾸어 피적분 함수의 특이점이 사라지도록 하는 해석적인 방법을 사용하였다. 실수축 적분방법에 의한 그린함수를 이용함으로써 불연속에 대한 정확한 특성을 구하였다.

• 한국전자파학회논문지
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• 제8권2호
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• pp.107-115
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• 1997

본 논문에서는 23 GHz 국간(Point-to-point) 통신용 Push-Push발진기를 Split Ring 공진기(Split Ring Resonator)를 사용하여 설계, 제작하였다. Split Ring 공진기(SRR)는 둥가회로를 이용한 이론적인 해석 및 MPIE(Mixed Potential Integral Equation)수칙해석 툴을 이용 해석하였다. 이 해석된 결과를 사용하여 전송 모드로 마이크로 스트립 라인과 결합된 SRR를 분석하였다. 제작된 발진기은 23 GHz에서 출력 전력은 4dBm, 기본 주파수 및 3차 고조파 억제는 - 20 dBc, - 34 dBc의 특성과 발진주파수에서 1 MHz offset에서 -109 d dEc/Hz의 SSB위상잡음 및 1.4%의 변환 효율을 나타내었다. 이 실험결과는 이론 및 시뮬레이션 결과와 일치함을 알 수 있다.