• Asian-Australasian Journal of Animal Sciences
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• v.7 no.3
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• pp.373-382
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• 1994

A bacterial strain No. 40, which produced extracellular endoglucanase, was isolated from the rumen of Korean native goals and identified to be a genus of Actinomyces sp. The optimum conditions for endoglucanase production in PY-CMC medium were initial pH of 7.0 and 4 days of cultivation at $39^{\circ}C$. When localization of endoglucanase activity of Actinomyces sp. was determined, 68% of the enzyme activity was found in the extracellular fraction, 11% of the activity was detected in the periplasmic space and the remaining activity was in the intracellular and cell-bound fractions. The maximal endoglucanase activity was observed at pH 5.0 and it was most s table at pH 5.0. The optimum temperature of this enzyme activity was $55^{\circ}C$, but enzyme activity was gradually lost at temperature above $60^{\circ}C$. The crude enzyme was activated by addition of 10 mM cysteine and 10 mM DTT. But it was inhibited by addition of 10 mM $Cu^{{+}{+}}$ and $Fe^{{+}{+}}$. This crude enzyme could digest carboxymethylcellulose (CMC), and degrade xylan, avicel, pNPG, and pNPC to a less extent.

• The Plant Pathology Journal
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• v.27 no.1
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• pp.59-67
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• 2011

A bacterial strain CH-67 which exhibits antagonism towards several plant pathogenic fungi such as Botrytis cinerea, Fulvia fulva, Rhizoctonia solani, Sclerotinia sclerotiorum, Colletotrichum sp. and Phytophthora sp. was isolated from forest soil by a chitin-baiting method. This strain was identified as Burkholderia cepacia complex (Bcc) and belonging to genomovar IX (Burkholderia pyrrocinia) by colony morphology, biochemical traits and molecular method like 16S rRNA and recA gene analysis. This strain was used to develop a bio-fungicide for the control of tomato leaf mold caused by Fulvia fulva. Various formulations of B. pyrrocinia CH-67 were prepared using fermentation cultures of the bacterium in rice oil medium. The result of pot experiments led to selection of the wettable powder formulation CH67-C containing modified starch as the best formulation for the control of tomato leaf mold. CH67-C, at 100-fold dilution, showed a control value of 85% against tomato leaf mold. Its disease control efficacy was not significantly different from that of the chemical fungicide triflumidazole. B. pyrrocinia CH-67 was also effective in controlling damping-off caused by Rhizoctonia solani PY-1 in crisphead lettuce and tomato plants. CH67-C formulation was recognized as a cell-free formulation since B. pyrrocinia CH-67 was all lethal during formulation process. This study provides an effective biocontrol formulation of biofungicide using B. pyrrocinia CH-67 to control tomato leaf mold and damping-off crisphead lettuce and tomato.

• Bulletin of the Korean Chemical Society
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• v.8 no.2
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• pp.96-101
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• 1987

2-Ethoxy-6-methoxy-5-cyano-3,4-dihydro-2H-pyran (1_a$), 2-n-butoxy-6-methoxy-5-cyano-3,4-dihydro-2H-pyr an (1b), 2-isobutoxy-6-methoxy-5-cyano-3,4-dihydro-2H-py ran ($1_c$), and 2-ethoxy-6-methoxy-3-methyl-5-cyano-3,4-dihydro -2H-pyran ($1_d$) were prepared by (4 + 2) cycloaddition reaction of methyl $\alpha$-cyanoacrylate with the corresponding alkyl vinyl ethers. Compounds $1_{a-d}$ were ring-open polymerized by cationic catalyst to obtain alternating head-to-head (H-H) copolymers. For comparison, head-to-tail (H-T) copolymer $3_a$ was also prepared by free radical copolymerization of the corresponding monomers. The H-H copolymer exhibited minor differences in its $1_H% NMR and IR spectra, but in the $^{13}C$ NMR spectra significant differences were observed between the H-H and H-T copolymers. Glass transition temperature ($T_g$) of H-H copolymer was higher than that of the H-T copolymer, but thermal decomposition temperature of the H-H copolymer was lower than that of the H-T copolymer. Compounds $1_a$, $a_b$, and $1_c$, copolymerized well with styrene by cationic catalyst, but compound 1d failed to copolymerize with styrene. All of the H-H and H-T copolymers were soluble in common solvents and the inherent viscosities were in the range 0.2-0.4 dl/g.

• Journal of Microbiology and Biotechnology
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• v.13 no.6
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• pp.984-988
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• 2003

The actinomycete strain KH-6l4 possessed strong antifungal activity, especially antagonistic to the rice blast fungus, Pyricularia oryzae. Diaminopimelic acid (DAP) type and morphological and physiological characteristics, examined by scanning electron microscopy (SEM), indicated that KH-614 belonged to the genus Streptomyces. Antifungal agent produced by this strain was found to be most active, when the strain was cultured in the presence of glucose, polypeptone, and yeast extract (PY) medium for 6 days at $27^{\circ}C$. Based on the spectral report data, MS and NMR, the antifungal agent was identified as cyclo(L-leucyl-L-prolyl). According to the antimicrobial activity test measured by minimal inhibitory concentration (MIC), the cyclo(1eu-pro) exhibited the activity against Candida albicans IAM 4905, Mucor ramannianus IAM6218, Rhizoctonia solani IFO 6218, Aspergilus fumigatus ATCC 42202, Glomerella cingulata IFO 9767, Trichophton mentagrophytes ATCC 18749, and Trichophyton rubrum ATCC 44766, the order of MIC values were 50, 12.5, 5, 50, 25, 5, $5\;\mu\textrm{g}/ml$, respectively. Specifically, cyclo(1eu-pro) was one of the most effective elements against Pyricularia oryzae IFO 5994 with the MIC value of $2.5\;\mu\textrm{g}/ml$, thus indicating that cyclo(leu-pro) is a potential antifungal agent.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 1999.04b
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• pp.361-365
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• 1999

This study examined the effects of multiple recycling on deinkability and properties of recycled paper from laser computer printout (LCPO). First, alkaline paper with a 20% printed area was disintegrated by TAPPI standard disintegrator at room temperature. After dewatering, the pulp was flotated and dried in oven at80$^{\circ}C$ for 24 hrs. A sequence of wetting, disintegrating, flotating and drying was one recycling cycle and this cyclic treatment was repeated from zero to five times. The recycled handsheet dropped to 90% of the original brightness after five cycles, and lost the most brightness after five cycles, and lost the most brightness in the first two cycles. However, it had a gain of 10% in opacity after five cycles as the same as the case of nonprinting. And, in this study, the method for determining residual ink(toner) content in recycled handsheets ere established by means of SEM-EDX and Py-GC. The change of residual ink percentage on recycled paper showed the effect of recycling numbers on deinkability of waste paper. A slight decrease in deinkability was noted for the recycled handsheets, which may be due to the change of fiber surface free energy connected with fiber swelling.

• Microbiology and Biotechnology Letters
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• v.18 no.3
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• pp.292-295
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• 1990

The bacterial strain KH-1167, identified as Ctoetridiunt sp. was found to produce the antibiotics KG-1167A & KG-1167B which showed a broad spectrum antibacterial activity. The highest antibiotics production was obtained in fermentation medium containing glucose, casamino acid and salt complex solution. Optimum culture condition for the maximum production of the antibiotics was also determined. Antibiotic productivity of the Clostridium sp. KH-1167 was increased to about 450% compared to that in the medium used for the primary isolation procedure.

• Journal of the Korean Chemical Society
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• v.41 no.10
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• pp.524-534
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• 1997

Analysis of additives in cured rubber is often a difficult task for analytical chemists because of a wide variety of complex components. Conventional analyses of additives and rubbers have been done in multistep, off-line processes with large sample size and extensive sample preparations. The coumarone-indene resin, resorcinol-formaldehyde resin, and prevulcanization inhibitor have been characterized by their pyrolysis pathways and mass spectra of characteristic pyrolyzates. Pyrolysis Gas Chromatography/Mass Spectrometry (Py-GC/MS) was used in the identification of additives without any sample pretreatment. This result shows that several organic additives in cured rubber can be directly analyzed.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.63-63
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• 2010

Ability to transport extracted carriers from NQDs is essential for the development of most NQD based applications. Strategies to facilitate carrier transport while preserving NQDs' optical characteristics include: 1) Fabricating neat films of NQDs with modified surfaces either by adapting series of ligands with certain limitations or by applying physical processes such as heat annealing 2) Coupling of NQDs to one-dimensional nanostructures such as single walled carbon nanotubes (SWNTs) or various types of nanowires. NQD-nanowire hybrid nanostructures are expected to facilitate selective wavelength absorption, charge transfer to 1-D nanostructures, and efficient carrier transport. Even with the vast interests in using NQD-SWNT hybrid materials in optoelectric applications, still, no reports so far have clearly elucidated the optoelectric behavior when they were assembled on the FET mainly because the complexity involving in both components in their preparation and characterization. We have monitored the optical properties of both components (NQDs, SWNTs) from the synthesis, to the assembly, and to the device. More importantly, by using pyridine molecules as a linker to non-covalently attach NQDs to SWNTs, we were able to assemble NQDs on SWNTs with precise density control without harming their electronic structures. Furthermore, by measuring electrical signals from the fabricated aligned SWNTs-FET using dielectrophoresis (DEP), we were able to elucidate the charge transfer mechanism.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2000.04a
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• pp.147-147
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• 2000

본 연구는 화장지용 펼프원료로 저급지인 색지(color ledger)고지를 사용함으로써 생산원 가를 절감하기 위한 목적으로 실시되었다. 일반적으로 색지 고지는 azo dyes, stilbene dyes, c copper phthalocyanine dyes와 같은 직접염료(direct dye)로 착색돼있는 것으로 보고되고있 다[) 한편, 펄프표백에 사용되는 약품은 hydrogen peroxide(HzOz), ozone(03), sodium h hypochloriten업oeD와 같은 산화표백제들과 F AS (formamidine sulfinic acid), sodium h hydrosulfite(NazSz04)와 같은 환원표백제들이 사용되는 것으로 널리 알려져 있다. 보통 화 장지용 펄프는 백색도가 78%이상이 되어야만 제품생산에 사용할 수 있는 것으로 인식되고 있다. 따라서 색지 고지를 이 목표로 달성하기 위한 탈색방법을 확립코자 다음과 같은 2가 지 실험을 실시하였다. 먼저, 색의 3원색인 빨강, 노랑, 파랑색의 색지 고지를 동일한 양으로 혼합하여 PY, HY, YH, YH, HY와 같은 5가지 방법의 실험을 실시하였다. 이중 YH 방법 이 가장 우수한 것으로 나타났다. 이 결과를 근거로 하여 여러 가지 색으로 구성된 색지 고 지가 50% 함유한 백상지 고지를 사용하여 Table과 같은 약품 및 조건으로 표백을 겸한 탈 묵실험을 실시하였다. 이 실험에서 백색도 81.8%, L* 93.3, a* -0.5, b* 4.1의 결과를 얻었다. 색지 고지의 탈색은 Y 단계에서 pH와 온도에 큰 영향을 받는 것으로 본 실험을 통하여 알 수가 있었다.

• Journal of the Korean Wood Science and Technology
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• v.47 no.4
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• pp.486-497
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• 2019

The non-isothermal and isothermal pyrolysis properties of H lignin and P lignin extracted from different biorefinery processes (such as supercritical water hydrolysis and fast pyrolysis) were studied using thermogravimetry analysis (TGA) and pyrolyzer-gas chromatography/mass spectrometry (Py-GC/MS). The lignins were characterized by ultimate/proximate analysis, FT-IR and GPC. Based on the thermogravimetry (TG) and derivative thermogravimetry (DTG) curves, the thermal decomposition stages were obtained and the pyrolysis products were analyzed at each thermal decomposition stage of non-isothermal pyrolysis. The isothermal pyrolysis of lignins was also carried out at 400, 500, and $600^{\circ}C$ to investigate the pyrolysis product distribution at each temperature. In non-isothermal pyrolysis, P lignin recovered from a fast pyrolysis process started to decompose and produced pyrolysis products at a lower temperature than H lignin recovered from a supercritical water hydrolysis process. In isothermal pyrolysis, guaiacyl and syringyl type were the major pyrolysis products at every temperature, while the amounts of p-hydroxyphenyl type and aromatic hydrocarbons increased with the pyrolysis temperature.