• 한국미생물·생명공학회지
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• 제51권4호
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• pp.425-431
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• 2023

The biopolymer produced by Lysinibacillus macroides can be useful as an emulsifying agent, flocculating agent, anti-oxidative agent, and anti-corrosive agent. The present work focused on the functional activities of this biopolymer such as bioflocculant and anti-corrosion. The results of the study for the biopolymer as a bioflocculating agent reveal that the biopolymer gave 72.3% flocculating activity against activated carbon at a concentration of 5 mg/l. In the optimization study, the highest bioflocculant activity was obtained in the presence of CaCl₂ mineral at 15% biopolymer concentration, 7.0 pH, and 40℃ temperature. The biopolymer was also studied for its anti-corrosive nature and observed that it was able to prevent corrosion of steel paper clips in a 6% CaCl₂ solution at a concentration of 0.5% after 7 days.

• The Plant Pathology Journal
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• 제18권6호
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• pp.301-307
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• 2002

Graft transmission and cytopathological studies of a severe pear disease, pear black necrotic leafspot（PBNLS), were carried out to determine the causal agent of the disease. No evidence was found that a fungal or bacterial pathogen could be the causal agent of the disease. Attempts to transmit the agent by sap-inoculation to other plants including herbaceous hosts failed. How-ever, the pathogen was readily graft-transmitted from symptomatic diseased pears to healthy pears. Graft transmission of the pathogen was also demonstrated by using an indicator plant, PS-95, developed in the laboratory through various grafting methods. Ultrastructural study of the disease revealed the consistent presence of flexuous rod-shaped virus-like particles (VLP) in the symptomatic leaves of both Niitaka cultivar and indicator pear, PS-95. The particles, approximately 12 nm in diameter with undetermined length, occurred in the cytoplasm of mesophyll parenchyma cells. Cells with VLPs also contained fibril-containing vesicles, which are common in cells infected with plant viruses with ssRNA genome. The vesicles were formed at the tonoplast. Based on the symptomatology, the presence of fibril-containing vesicles, and graft-transmissibility, it is believed that the VLPs that occurred on symptomatic leaves of black necrotic leafspot of pear are viral in nature, possibly those of a capillovirus.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2005년도 추계학술대회 및 정기총회
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• pp.189-206
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• 2005

Much of work on network externality assumed network effects are dependent on the network size. Therefore, very little consideration is given to the view that marginal benefits from joining the network may not increase with the network size if consumer benefits come from the direct interaction with neighbors, namely local network. In this study, we used the agent-based simulation method to reexamine the effectiveness of the traditional network market strategy under the presence of the local network where two incompatible technologies compete. We found that the strategy of growing an initial customer base is not effective under the presence of the local network. Our study also showed that targeting customers based on their technology Preference is not as effective as targeting customers within the same local network. As a result, the focus of a network market strategy should be directed to taking advantage of the customer network.

• 한국세라믹학회지
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• 제54권2호
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• pp.102-107
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• 2017

The dependence of the IR optical properties of PMMA/$Al_2O_3$ nanocomposite on the alumina content was investigated in the wavelength range of $3500-2800cm^{-1}$. The samples were prepared via emulsion polymerization technique using oleic acid as a coupling agent. Grafting density calculations were carried out by means of elemental analysis CHN to yield the best coupling agent content. FTIR analysis confirmed the existence of a chemical bond between aluminum oxide and oleic acid. The outcomes of XRD analyses showed the presence of cubic gamma aluminum oxide in the nanocomposite, in contrast to the amorphous nature of PMMA. TEM images showed the core-shell morphology of the particles other than pristine PMMA. Optical constants of the nanocomposite were calculated based on FTIR spectra and the Kramers-Kronig equations. The presence of nano alumina modified some of the optical indexes in IR region.

• 대한화학회지
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• 제29권4호
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• pp.437-440
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• 1985

유기아지드화물은 일산화탄소대기압하, 실온에서 높은 선택적 환원시약인 테트라카르 보닐철산염의 존재하에서 높은 수득율의 아민으로 환원되었다. 특히 벤조일아지드는 동일시약내 일산화탄소 대기압 실온에서는 에틸페닐카바메이트를 주나, -40$^{\circ}$에서는 정량적으로 벤즈아미드가 얻어졌다.

• 전기전자학회논문지
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• 제18권4호
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• pp.517-522
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• 2014

본 논문은 임의의 네트워크 시간 지연이 존재하는 선형 다개체 시스템의 일치문제를 다룬다. 다개체 시스템의 상태일치를 위한 충분조건은 선형행렬방정식을 이용하여 제공된다. 또한, 제안한 충분조건아래에서 임의의 크기를 갖는 네트워크 지연이 존재하는 경우에도 일치에 도달할 수 있음을 증명한다. 마지막으로 제안한 결과의 유효성을 증명하기 위하여 수치 예제를 제공한다.

• Archives of Pharmacal Research
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• 제24권1호
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• pp.16-20
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• 2001

2-(Allylthio)pyrazine derivatives were designed as a novel cancer chemopreventive agent that functions through selective inhibtion of cytochrome P-450 and induction of phase 11 enzymes involved in the detoxification of carcinogens. A practical preparation method of 2-(allylthio) pyrazine derivatives was established by the reaction of 2-mercaptopyrazine and allylbromides in the presence of a catalytic antioxidant, DABCO (1,4-diazabicyclo[2,2,2] octane), in dimethyl-formamide at below $50^{\circ}C$.

• 한국염색가공학회지
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• 제2권2호
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• pp.14-19
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• 1990

The setting behavior of disulfide-enriched wool and disulfide-crosslinked silk obtained by treatment with a disulfide-containing crosslinking agent, bis $(\beta-isocyanatoethyl)$ dissulfide was compared with that of untreated wool and silk under the absence and the presence of a reducing agent. Rearrangment of secondary bonds facilitated by cleavage of crosslinks as well as rearrangement of crosslinks itself seems to play an important role in the set stability.

• 충청수학회지
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• 제32권2호
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• pp.215-224
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• 2019

We investigate the optimal consumption and investment decision problem of an agent whose time preference is time-inconsistent. Specifically, for a time-separable utility function, the agent's subjective discount factor is supposed to be changed randomly in the future. We provide closed-form solutions in the presence of income process. The method can be extended into the case with a stochastic income process.

• Bulletin of the Korean Chemical Society
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• 제9권6호
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• pp.352-355
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• 1988

${\alpha},{\beta}$-unsaturated carboxylic acid derivatives such as esters, amides, and nitriles are readily reduced to the corresponding saturated derivatives by potassium triphenylborohydride, $KPh_3BH$, in the presence of phenol, a quenching agent, in excellent yields.