• 한국물환경학회지
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• 제34권1호
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• pp.46-56
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• 2018

A mcyB-specific Ultra-Rapid quantitative PCR was developed for the quantitative detection of Microcystis aeruginosa, which is often a dominant species in green tide. McyB-specific UR-qPCR was optimized under extremely short times of each step in thermal cycles, based on the specific primers deduced from the mcyB in microcystin synthetase of M. aeruginosa. The M. aeruginosa strain KG07 was used as a standard for quantification, after the microscopic counting and calculation by mcyB-specific UR-qPCR. The water samples from the river water with the Microcystis outbreak were also measured by using both methods. The $1.0{\times}10^8$ molecules of mcyB-specific DNA was recognized inner 4 minutes after beginning of UR-qPCR, while $1.0{\times}10^4$ molecules of mcyB-specific templates was detected inner 7 minutes with quantitative manner. From the range of $1.0{\times}10^2$ to $1.0{\times}10^8$ initial molecules, quantification was well established based on $C_T$ using mcyB-specific UR-qPCR (Regression coefficiency, $R^2=0.9977$). Between the numbers of M. aeruginosa cell counting under microscope and calculated numbers using mcyB-specific UR-qPCR, some differences were often found. The reasons for these differences were discussed; therefore, easy compensation method was proposed that was dependent on the numbers of the cell counting. Additionally, to easily extract the genomic DNA (gDNA) from the samples, a freeze-fracturing of water-sample using liquid nitrogen was tested, by excluding the conventional gDNA extraction method. It was also verified that there were no significant differences using the UR-qPCR with both gDNAs. In conclusion, the mcyB-specific UR-qPCR that we proposed would be expected to be a useful tool for rapid quantification and easy monitoring of M. aeruginosa in environmental water.

• 한국산학기술학회논문지
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• 제21권8호
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• pp.475-484
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• 2020

이 논문은 TV광고의 일반인 모델 인식에 관하여, 기능적인 양적 분석의 과거 행태로부터 탈피하여, 심층적이고 효과적으로 접근할 수 있는 주관성연구인 실증적인 Q방법론으로 연구되었다. 또한 이 분석에서는 기존 논의에서 연역적인 가설을 도출하는 종래의 연구 방법과는 달리, 사람들의 주관적 이미지에 의한 새로운 가설발견의 목적이 있다. 구체적으로 Q요인분석이란 통계방법을 사용하며, R방법의 변수를 요인화가 아닌 사람을 요인화하는 것이다. 이 연구에서는 TV광고의 일반인 모델에 대해 젊은 층의 수용행태 분석을 알아보는 것이다. 분석결과는 총 4가지의 유형{제 1유형[(N=7) : 광고 공감대형(Advertising Consensus Type)], 제 2유형[(N=7) : 광고 부정형(Advertising Negative Type)], 제 3유형[(N=5) : 광고 구매력 감소형(Advertising Purchasing Reduction Type)], 제 4유형[(N=1) : 광고 설득 지향형(Advertising Persuasion Orientation Type)]}으로 분류되었으며, 전반적으로 매우 차별적인 유형들로 발견되었다. 결론적으로, 이 연구는 TV광고의 일반인 모델인식에 대한 주로 젊은 응답자들의 주관적 수용 행태를 검토하였다. 또한 분석의 내용들은 관련 이슈와 아젠다 연구를 위한 발전적인 제안(개선)을 제시하는데 유의미한 논의를 제시하는 것이다.

• 한국식품조리과학회지
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• 제31권5호
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• pp.660-675
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• 2015

This study was performed to assess the nutrient intake and dietary diversity of Korean children and adolescents using the Korean dietary pattern index developed in previous studies. For this study, 6,462 children and adolescents aged 7~18y who participated in the dietary intake survey (24h recall method) of the 2007~2013 KNHANES were sampled. The food items included in the Korean dietary index were jusik-ryu, guk/tang-ryu, gui/jjim-ryu, namul-ryu, yeomjangchaeso-ryu, jang-ryu and mitbanchan-ryu. All the subjects and both age groups (7~12y, 13~18y) were divided into quartiles. According to the results of this study, the range of the Korean dietary pattern score was 0~58 for all of the subjects and also in the 13~18 age group, and was 0~52 in the 7~12y age group. When the pattern score for each food group was compared across the quartiles of the Korean dietary pattern score, in all the subjects as well as in the 7~12y and 13~18y age groups, the pattern score for jusik-ryu and yeomjangchaeso-ryu was highest in Q1~Q4. or all the food groups, the mean pattern score was highest in Q4. These results suggested that the Korean dietary pattern score is highly associated with jusik-ryu including rice and yeomjangchaeso-ryu including kimchi. Accordingly, it is considered necessary to develop an index that reflects the characteristics of Korean cuisine and, at the same time, assesses the nutritional status and food consumption tendency of Korean children and adolescents.

• Transactions on Electrical and Electronic Materials
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• 제10권4호
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• pp.121-124
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• 2009

In this study, in order to develop compositions of ceramics suitable for piezoelectric actuator and ultrasonic vibrator applications using low temperature sintering, multilayer, PMN-PNN-PZT ceramics were fabricated using $Li_2CO_3$ and $Na_2CO_3$ as sintering aids. Their structural, piezoelectric and dielectric characteristics were investigated according to the Zr/Ti ratio. As the Zr/Ti ratio increased, the electromechanical coupling factor $k_p$, and piezoelectric constant $d_{33}$ and the mechanical quality factor $Q_m$ all increased with Zr/Ti ratio and then decreased after the ratio exceeded 50/50. At the ratio of Zr/Ti =49/51 and sintering temperature of $900^{\circ}C$; the density, electromechanical coupling factor $k_p$, dielectric constant ${\varepsilon}_r$ piezoelectric $d_{33}$ constant and mechanical quality factor $Q_m$ all showed the optimum values of 7.900 $g/cm^3$, 0.576, 856, 312 pC/N, 1,326, respectively. These property values are very suitable for multilayer ceramics actuator applications.

• Journal of Microbiology and Biotechnology
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• 제23권10호
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• pp.1460-1471
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• 2013

Microalgal biofuel production from wastewater has economic and environmental advantages. This article investigates the lipid production from high chemical oxygen demand (COD) bioethanol wastewater without dilution or additional nutrients, using a newly isolated heterotrophic microalga, Chlorella vulgaris LAM-Q. To enhance lipid accumulation, the combined effects of important operational parameters were studied via response surface methodology. The optimal conditions were found to be temperature of $22.8^{\circ}C$, initial pH of 6.7, and inoculum density of $1.2{\times}10^8cells/ml$. Under these conditions, the lipid productivity reached 195.96 mg/l/d, which was markedly higher than previously reported values in similar systems. According to the fatty acid composition, the obtained lipids were suitable feedstock for biodiesel production. Meanwhile, 61.40% of COD, 51.24% of total nitrogen, and 58.76% of total phosphorus were removed from the bioethanol wastewater during microalgal growth. In addition, 19.17% of the energy contained in the wastewater was transferred to the microalgal biomass in the fermentation process. These findings suggest that C. vulgaris LAM-Q can efficiently produce lipids from high-concentration bioethanol wastewater, and simultaneously performs wastewater treatment.

• Bulletin of the Korean Chemical Society
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• 제15권10호
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• pp.832-835
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• 1994

The ${alpha}$-amylase gene of Bacillus licheniformis has been cloned and two mutant ${alpha}$-amylase genes of which histidine 235 was changed to glutamine (H235Q) and aspartic acid 328 to glutamic acid (D328E) have been produced by site-directed mutagenesis. The kinetic parameters, optimum pH and thermostability of wild type(WT) and these two mutant amylases expressed in E. coli MC1061 have been compared after purification. The $K_m$ values of WT, H235Q and D328E ${alpha}$-amylases were 0.22%, 0.73%, and 0.80% respectively, when using starch as the substrate. The $V_max$ values of wild type ${alpha}$ -amylase and mutant ${alpha}$-amylases were 0.6-0.7%/minute, and did not show any significant differences among them. The optimum pH of D328E ${alpha}$-amylase was shifted to more acidic pH. Also, the thermostability of H235Q ${alpha}$-amylase was increased compared to the wild type ${alpha}$-amylase.

• 한국응용곤충학회지
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• 제50권4호
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• pp.315-324
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• 2011

본 연구는 우리나라의 작물 재배지에서 문제가 되고 있는 뿌리혹선충의 환경친화적 방제를 위하여 30종의 약용식물(32 시료)을 선발하여 당근뿌리혹선충 2령충과 알에 대한 살선충 효과와 난 부화억제 효과를 검정하였다. 약용식물 추출물들 중 원화(Daphne genkwa), 건강(Zingiber officinale), 정향(Eugenia caryophyllata), 사군자(Quisqualis indica) 등이 1,000 ppm 농도에서 당근뿌리혹선충 J2 유충에 대하여 80%이상의 살선충 활성을 보였다. 이들 중 원화와 사군자는 125 ppm에서도 91 %와 99%의 살선충 활성을 보였다. 추출방법(메탄올 또는 헥산, 온수추출, 냉수 추출)에 따라 살선충 효과에 차이를 보였는데 건강과 사군자는 1,000 ppm 온수추출물 처리 시 각각 99%의 살선충 효과를 보였고, 냉수추출물에서는 36%와 98%의 살선충 효과를 보였다. 사군자는 모든 추출물 처리에서 높은 살선충 활성을 보였다. 빈랑(Areca catechu)과 원화, 청주항(Desmodium caudatum), 흑축(Pharbitis nil), 사군자, 건강 추출물을 이용하여 당근뿌리혹선충 알의 부화억제 효과를 조사한 결과 1,000 ppm 농도에서 원화와 흑축, 사군자 처리는 처리 7, 14, 21 일째까지 낮은 부화 수를 나타내었다. Pot와 인삼 밭에서 1,000 ppm 농도의 사군자 메탄올 추출물 처리 시 토양 중의 당근뿌리혹선충 밀도를 유의하게 감소시켰다. 따라서 사군자 추출물은 당근뿌리혹선충의 환경친화적 방제에 활용 가능할 것으로 판단된다.

• Journal of Microbiology and Biotechnology
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• 제11권1호
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• pp.40-49
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• 2001

The present work presents a novel approach for the dynamic quantification of respiration rates on a small scale by using lysine-producing Corynebacterium glutamicum ATCC 21253. Cells sampeld from batch cultures at different times were incubated ina 12-ml scale bioreactor equipped with a membrane mass spectrometer. Under dynamic conditions, gas exchange across the gas-liquid phase, specific respiration rates, and RQ values were precisely measured. For this purpose, suitable mass balances were formulated. The transport coefficients for $O_2$ and $CO_2$, crucial for calculating the respiration activity, were determined as $k_La_{O2}=9.18h^{-1}$ and $k_La_{CO2}=5.10h^{-1}$ at 400 rpm. The application of the proposed method to batch cultures of C. glutamicum ATCC 21253 revealed the maximum specific respiration rates of $q_{O2}=8.4\;mmol\;g^{-1}h^{-1}\;and\;q_{CO2}=8.7\;mmol\;g^{-1}h^{-1}$ in the middle of the exponential growth phase after 5 h of cultivation. When the cells changed from growth to lysine production due to the depletion of the essential amino acids theonine, methionine, and leucine, $q_{O2}\;and\;q_{CO2}$ decreased significantly and RQ increased. The respiration data exhibited an excellent agreement with previous cultivations of the strain [13]. This confirms the potential of the developed approach to realistically reflect the metabolic activities of cells at their point of sampling. The short-term influence of added threonine, methionine, and leucine was highest during the shift from growth to lysine production, where $q_{O2}\;and\;q_{CO2}$ increased 50% within one minute after the pulse addition of these compounds. Non-growing, yet lysine-producing cells taken from the end of the batch cultivation revealed no metabolic stimulation with the addition of threonine, methionine, and leucine.

• Journal of Ecology and Environment
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• 제35권3호
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• pp.243-249
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• 2012

Biomass expansion factors, which convert timber volume (or dry weight) to biomass, are used for estimating the forest biomass and accounting for the carbon budget at a regional or national scale. We estimated the biomass conversion and expansion factors (BCEF), biomass expansion factors (BEF), root to shoot ratio (R), and ecosystem biomass expansion factor (EBEF) for Quercus mongolica Fisch. and Quercus variabilis Bl. forests based on publications in Korea. The mean BCEF, BEF, and R for Q. mongolica was 1.0383 Mg/$m^3$ (N = 27; standard deviation [SD], 0.5515), 1.3572 (N = 27; SD, 0.1355), and 0.2017 (N = 32; SD, 0.0447), respectively. The mean BCEF, BEF, and R for Q. variabilis was 0.7164 Mg/$m^3$ (N = 17; SD, 0.3232), 1.2464 (N = 17; SD, 0.0823), and 0.1660 (N = 8; SD, 0.0632), respectively. The mean EBEF, as a simple method for estimating the ground vegetation biomass, was 1.0216 (N = 7; SD, 0.0232) for Q. mongolica forest ecosystems, and 1.0496 (N = 8; SD, 0.0725) for Q. variabilis forest ecosystems. The biomass expansion factor values in this study may be better estimates of forest biomass in Q. mongolica or Q. variabilis forests of Korea compared with the default values given by the Intergovernmental Panel on Climate Change (IPCC).

• 한국전기전자재료학회논문지
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• 제20권12호
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• pp.1049-1055
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• 2007

Lots of integration work has been done in order to miniaturize the devices for communication. To do this work, one of key work is to get miniaturized inductor with high Q factor for RF circuitry. However, it is not easy to get high Q inductor with silicon based substrate in the range of GHz. Although silicon is well known for its good electrical and mechanical characteristics, silicon has many losses due to small resistivity and high permittivity in the range of high frequency. MEMS technology is a key technology to fabricate miniaturized devices and LTCC is one of good substrate materials in the range of high frequency due to its characteristics of high resistivity and low permittivity. Therefore, we proposed and studied to fabricate and analyze the inductor on the LTCC substrate with MEMS fabrication technology as the one of solutions to overcome this problem. We succeeded in fabricating and characterizing the high Q inductor on the LTCC substrate and then compared and analyzed the results of this inductor with that on a silicon and a glass substrate. The inductor on the LTCC substrate has larger Q factor value and inductance value than that on a silicon and a glass substrate. The values of Q factor with the LTCC substrate are 12 at 3 GHz, 33 at 6 GHz, 51 at 7 GHz and the values of inductance is 1.8, 1.5, 0.6 nH in the range of 5 GHz on the silicon, glass, and LTCC substrate, respectively.