• Mycobiology
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• 제44권3호
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• pp.171-179
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• 2016

In the screening of marine mangrove derived fungi for lovastatin productivity, endophytic Aspergillus luchuensis MERV10 exhibited the highest lovastatin productivity (9.5 mg/gds) in solid state fermentation (SSF) using rice bran. Aspergillus luchuensis MERV10 was used as the parental strain in which to induce genetic variabilities after application of different mixtures as well as doses of mutagens followed by three successive rounds of genome shuffling. Four potent mutants, UN6, UN28, NE11, and NE23, with lovastatin productivity equal to 2.0-, 2.11-, 1.95-, and 2.11-fold higher than the parental strain, respectively, were applied for three rounds of genome shuffling as the initial mutants. Four hereditarily stable recombinants (F3/3, F3/7, F3/9, and F3/13) were obtained with lovastatin productivity equal to 50.8, 57.0, 49.7, and 51.0 mg/gds, respectively. Recombinant strain F3/7 yielded 57.0 mg/gds of lovastatin, which is 6-fold and 2.85-fold higher, respectively, than the initial parental strain and the highest mutants UN28 and NE23. It was therefore selected for the optimization of lovastatin production through improvement of SSF parameters. Lovastatin productivity was increased 32-fold through strain improvement methods, including mutations and three successive rounds of genome shuffling followed by optimizing SSF factors.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2009년도 춘계 학술대회 제21권1호
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• pp.423-424
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• 2009

최근 자원의 재활용 및 알칼리-골재반응의 대책으로 F/a의 사용이 증가하는 추세이다. 그러나 F/a 치환량 증가에 따른 미연소탄소의 AE제 흡착으로 인하여 공기연행성능이 저하되어, 동결융해 작용에 의한 내구성 저하의 위험성이 고조되고 있다. 따라서 본 연구에서는 F/a 치환량 및 AE제 종류변화에 따른 굳지 않은 콘크리트의 공기연행성능을 분석함으로써 F/a를 다량 사용한 콘크리트의 기포안정성 향상을 위한 기초자료로 제시하고자 한다.

• 한국식품영양학회지
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• 제22권1호
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• pp.97-102
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• 2009

본 연구에서는 독성이 적고, 활성이 높으면서 안정한 새로운 tyrosinase 저해제를 미생물을 대상으로 얻고자 tyrosinase 저해제를 강하게 분비하는 방선균 F-97을 토양으로부터 분리하였다. 이 균의 기균사는 회색의 나뭇가지형 (tree type)이며, 포자의 끝부분이 유선형으로 회전되어 있고, 포자 표면은 구형의 smooth형으로 분류되었다. 세포벽의 DAP 성분은 LL-DAP이었으며, 세포균체의 당 성분은 검출되지 않았다. 기타 배양학적 및 생리적 특성을 종합한 결과 streptomyces aburaviensis 또는 근연균으로 추정된다.

• 지구물리
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• 제9권3호
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• pp.199-207
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• 2006

Fukuoka earthquake on March 20, 2005 showed the potential hazard of large events out of S. Korea. From the viewpoint of seismic hazard, seismic amplitude decrease Q-1 is very important. Related to the crustal cracks induced by the earthquakes, the value of Q-1- high Q-1 regions are more attenuating than low Q-1 regions - shows a correlation with seismic activity; relatively higher values of Q-1 have been observed in seismically active areas than in stable areas. For the southeastern and central S. Korea, we first simultaneously estimated QP-1 and QS-1 by applying the extended coda-normalization method to KIGAM and KNUE network data. Estimated QP-1 and QS-1 values are 0.009 f-1.05 and 0.004 f-0.70 for southeastern S. Korea and 0.003 f -0.54 and 0.003 f -0.42 for central S. Korea, respectively. These values agree with those of seismically inactive regions such as shield. The low QLg-1 value, 0.0018f -0.54 was also obtained by the coda normalization method. In addition, we studied QLg-1 by applying the source pair/receiver pair (SPRP) method to both domestic and far-regional events. The obtained QLg-1 for all Fc is less than 0.002, which is reasonable value for a seismically inactive region.

• 한국재료학회지
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• 제29권6호
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• pp.371-377
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• 2019

A flexible piezoelectric energy harvester(f-PEH) that converts tiny mechanical and vibrational energy resources into electric signals without any restraints is drawing attention as a self-powered source to operate flexible electronic systems. In particular, the nanocomposites-based f-PEHs fabricated by a simple and low-cost spin-coating method show a mechanically stable and high output performance compared to only piezoelectric polymers or perovskite thin films. Here, the non-piezoelectric polymer matrix of the nanocomposite-based f-PEH is replaced by a P(VDF-TrFE) piezoelectric polymer to improve the output performance generated from the f-PEH. The piezoelectric hybrid nanocomposite is produced by distributing the perovskite PZT nanoparticles inside the piezoelectric elastomer; subsequently, the piezoelectric hybrid material is spin-coated onto a thin metal substrate to achieve a nanocomposite-based f-PEH. A fabricated energy device after a two-step poling process shows a maximum output voltage of 9.4 V and a current of 160 nA under repeated mechanical bending. Finite element analysis(FEA) simulation results support the experimental results.

• Macromolecular Research
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• 제17권12호
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• pp.963-968
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• 2009

Liquid crystal (LC; E7 and/or ML-0249)-embedded, poly(vinylidenefluoride-co-hexafluoropropylene) (PVdF-co-HFP)-based, polymer electrolytes were prepared for use in dye-sensitized solar cells (DSSCs). The electrolytes contained 1-methyl-3-propylimidazolium iodide (PMII), tetrabutylammonium iodide (TBAI), and iodine ($I_2$), which participate in the $I_3^-/I^-$ redox couple. The incorporation of photochemically stable PVdF-co-HFP in the DSSCs created a stable polymer electrolyte that resisted leakage and volatilization. DSSCs, with liquid crystal(LC)-embedded PVdF-co-HFP-based polymer electrolytes between the amphiphilic ruthenium dye N719 absorbed to the nanocrystalline $TiO_2$ photoanode and the Pt counter electrode, were fabricated. These DSSCs displayed enhanced redox couple reduction and reduced charge recombination in comparison to that fabricated from the conventional PVdF-co-HFP-based polymer electrolyte. The behavior of the polymer electrolyte was improved by the addition of optimized amounts of plasticizers, such as ethylene carbonate (EC) and propylene carbonate (PC). The significantly increased short-circuit current density ($J_{sc}$, $14.60\;mA/cm^2$) and open-circuit voltage ($V_{oc}$, 0.68 V) of these DSSCs led to a high power conversion efficiency (PCE) of 6.42% and a fill factor of 0.65 under a standard light intensity of $100\;mW/cm^2$ irradiation of AM 1.5 sunlight. A DSSC fabricated by using E7-embedded PVdF-co-HFP-based polymer electrolyte exhibited a maximum incident photon-to-current conversion efficiency (IPCE) of 50%.

• 한국균학회지
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• 제25권4호통권83호
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• pp.362-368
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• 1997

재조합 DNA probe를 이용하여 국내 Fusarium oxysporum 분화형간의 분류 가능성을 탐색하고 그들의 유전적 변이를 분석하였다. F. oxysporum f. sp. lycopersici, cucumerinum, fragariae, garlic, sesami 등 5종의 분화형을 공시하여 RFLP 분석을 실시하였다. Repetitive copy clone인 세종의 재조합 클론 pFC46, pFC52, pFC57을 이용하여 HindIII로 처리한 F. oxysporum의 genomic DNA에 대해 southern hybridization한 결과 나타난 밴드의 양상은 분화형에 따라 차이가 명확히 밝혀져 이들을 이용한 분류가 가능하였다. 또한 RFLP 분석 결과 f. sp. sesami는 다른 분화형에 비해 다소 변이가 심했으나 다른 분화형들은 변이가 거의 없어 f. sp. sesami를 제외한 f. sp. lycopersici 등 4종의 Fusarium oxysporum 분화형의 균주들은 채집 지역에 관계없이 대체로 유전적으로 안정되어 있는 것으로 판단되었다. Hybridization밴드의 양상에 기초하여 유전적 유연관계를 집괴 분석한 결과 각 분화형별로 유사도가 매우 높게 별도의 유사군을 형성하였다.

• 한국음향학회지
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• 제19권5호
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• pp.60-64
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• 2000

본 논문에서는 소프라노가 성악 발성으로 한국어 단모음을 발음할 때, 그 단모음들의 포르만트가 F0(Fundamental frequency)에 따라 어떻게 바뀌어지는지 연구되었다. 일반적으로 다른 파트의 경우와는 달리, 소프라노가 노래를 할 때에는 포르만트가 그 F0의 영향을 크게 받는 것으로 알려져 있다. 따라서, 성악발성에 대한 연구를 위해서는 소프라노가 발성할 수 있는 전 음역 대의 F0에서 각 모음에 대한 포르만트 분석이 필요하다. 이러한 분석 결과를 바탕으로 성악 발성의 특징들을 패턴화하여 성악발성 평가 시스템이나 성악발성 합성 시스템을 구축할 수 있다. 5명의 전문 소프라노를 대상으로 '아, 에, 이, 오, 우' 5모음의 성악발성을 A3(220.0Hz)에서부터 A5(880.0Hz)까지의 피치에서 포르만트 분석을 하였다. 또한, 일반적인 대화 시 이 5가지 모음의 포르만트를 분석하여 성악발성의 경우와 비교하였다. 연구 결과, '아, 에, 이'의 F2/F1의 그래프가, B4(493.8Hz)이상의 F0에서는 거의 직선으로 나타났다. B4는 Changing Voice가 시작되는 곳으로, 성악가의 음색 변화가 포르만트 형태의 변화와 밀접한 관계가 있음을 알 수 있다. 또한, A5에서는 '아, 에, 이, 오, 우'의 F1, F2의 수치가 거의 일치하는 것으로 나타났다. 즉, 최고음부에서 불려지는 모음들은 서로 구별되기가 어렵게 되는 것이다. 본 논문은 성악발성 평가 시스템이나 성악발성 합성 시스템을 구축할 때에, '아, 오, 우'의 경우에는 B4에서 A5의 F1, F2를 F0대한 기울기로 규정화할 것을 제안한다. 이와 같은 규정화를 통하여 성악발성과 관련된 시스템 구축에 필요한 노력과 비용을 줄일 수 있을 것이다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2015년도 학술발표회
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• pp.106-106
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• 2015

The information of flow regimes continues to be norm in water resource and watershed management, in that stream flow regime is a crucial factor influencing water quality, geomorphology, and the community structure of stream biota. The objectives of this study were to estimate Korean stream flows from landscape variables, classify stream flow gages using hydraulic characteristics, and then apply these methods to ungaged biological monitoring sites for effective ecological assessment. Here I used a linear modeling approach (MLR, PCA, and PCR) to describe and predict seasonal flow statistics from landscape variables. MLR models were successfully built for a range of exceedance discharges and time frames (annual, January, May, July, and October), and these models explained a high degree of the observed variation with r squares ranging from 0.555 (Q95 in January) to 0.899 (Q05 in July). In validation testing, predicted and observed exceedance discharges were all significantly correlated (p<0.01) and for most models no significant difference was found between predicted and observed values (Paired samples T-test; p>0.05). I classified Korean stream flow regimes with respect to hydraulic and hydrologic regime into four categories: flashier and higher-powered (F-HP), flashier and lower-powered (F-LP), more stable and higher-powered (S-HP), and more stable and lower-powered (S-LP). These four categories of Korean streams were related to with the characteristics of environmental variables, such as catchment size, site slope, stream order, and land use patterns. I then applied the models at 684 ungaged biological sampling sites used in the National Aquatic Ecological Monitoring Program in order to classify them with respect to basic hydrologic characteristics and similarity to the government's array of hydrologic gauging stations. Flashier-lower powered sites appeared to be relatively over-represented and more stable-higher powered sites under-represented in the bioassessment data sets.

• Journal of Microbiology and Biotechnology
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• 제33권9호
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• pp.1170-1178
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• 2023

Food allergy represents a severe problem for many societies, including sensitive populations, academies, health authorities, and the food industry. Peanut allergy occupies a special place in the food allergy spectrum. To prevent consumption by consumers suffering from a peanut allergy, a rapid and sensitive detection method is essential to identify unintended peanut adulteration in processed foods. In this study, we produced four monoclonal antibodies (MAbs; RO 3A1-12, PB 4C12-10, PB 5F9-23, and PB 6G4-30) specific to thermo-stable and soluble proteins (TSSPs) of peanut and developed an enzyme-linked immunosorbent assay (ELISA) based on the MAbs. Among them, PB 5F9-23 MAb was firmly bound to Ara h 1, and other MAbs strongly reacted to Ara h 3 in the Western blot analysis. An antibody cocktail solution of the MAbs was used to enhance the sensitivity of an indirect ELISA, and the limit of detection of the indirect ELISA based on the antibody cocktail solution was 1 ng/ml and improved compared to the indirect ELISA based on the single MAb (11 ng/ml). The cross-reaction analysis revealed the high specificity of developed MAbs to peanut TSSPs without cross-reaction to other food allergens, including nuts. Subsequently, analyzing processed foods by indirect ELISA, all foods labeled as containing peanuts in the product description were confirmed to be positive. The results indicate that the developed antibodies exhibit high specificity and sensitivity to peanuts and can be used as bio-receptors in immunoassays or biosensors to detect intentional or unintentional adulteration of peanuts in processed foods, particularly heat-processed foods.