• Journal of Microbiology
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• 제44권5호
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• pp.530-536
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• 2006

Bacteriophage P4, a satellite phage of coliphage P2, is a very useful experimental tool for the study of viral capsid assembly and cos-cleavage. For an in vitro cos-cleavage reaction study of the P2-P4 system, new shortened and selectable markers containing P4 derivative plasm ids were designed as a substrate molecules. They were constructed by swapping the non-essential segment of P4 DNA for either the kanamycin resistance (kmr) gene or the ampicillin resistance (apr) gene. The size of the genomes of the resulting markers were 82% (P4 ash8 delRI:: kmr) and 79% (P4 ash8 delRI:: apr) of the wild type P4 genome. To determine the lower limit of genome size that could be packaged into the small P4-size bead, these shortened P4 plasmids were converted to phage particles with infection of the helper phage P2. The conversion of plasmid P4 derivatives to bacteriophage particles was verified by the heat stability test and the burst size determination experiment. CsCl buoyant equilibrium density gradient experiments confirmed not only the genome size of the viable phage form of shortened P4 derivatives, but also their packaging into the small P4-size head. P4 ash8 delRI:: apr turned out to be the smallest P4 genome that can be packaged into P4-sized head.

• 한국조명전기설비학회지:조명전기설비
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• 제8권4호
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• pp.38-45
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• 1994

본 논문에서는 신호감쇄 및 연집잡음(burst noise)이 존재하는 전력선 반송 채널에서 디지틀 데이터를 복조하기 위한 BPSK(Binary Phase Shift Keying) 복조기의 설계에 대하여 논한다. 이러한 BPSK 복조기의 실현에 있어서 반송파 동기호로는 소형화 및 안정화가 요구되며, 입력주파수의 변동에 대해서 낮은 위상 오차가 필요하게 된다. 이와 같은 요구조건을 만족하기 위해서 본 논문에서는 반송주파수가 10.4[kHz]이고, 전송속도가 110[bps]인 재변조방식의 BPSK 복조기를 설계 제작하였다. 설계 제작한 반송파 동기회로는 기존의 아날로그 소자로 구성되었던 승산기(multiplier) 및 지연회로를 PLL(Phase Locked Loop) IC로 대치하여 소형화 및 안정성을 확보하였으며, PLL회로 설계시에 주위온도 등을 고려하여 주파수 인입범위를 $\pm$4[kHz], 정상위상오차를 $\pm$60로 설정하였다. 기능시험 결과로부터, BPSK 복조기의 동작기능은 정상상태에서 설계조건에 만족함을 알 수 있었다.

• The Plant Pathology Journal
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• 제34권1호
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• pp.59-64
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• 2018

Bacteriophages of Acidovorax citrulli, the causal agent of bacterial fruit blotch, were isolated from 39 watermelon, pumpkin, and cucumber leaf samples collected from various regions of Korea and tested against 18 A. citrulli strains. Among the six phages isolated, ACP17 forms the largest plaque, and exhibits the morphology of phages in the Myoviridae family with a head diameter of $100{\pm}5nm$ and tail length of $150{\pm}5nm$. ACP17 has eclipse and latent periods of $25{\pm}5min$ and $50{\pm}5min$, respectively, and a burst size of 120. The genome of ACP17 is 156,281 base pairs with a G + C content of 58.7%, 263 open reading frames, and 4 transfer RNA genes. Blast search and phylogenetic analysis of the major capsid protein showed that ACP17 has limited homology to two Stentrophomonas phages, suggesting that ACP17 is a new type of Myoviridae isolated from A. citrulli.

• 한국정밀공학회지
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• 제7권3호
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• pp.75-82
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• 1990

Automatic monitoring of the cutting conditions is one of the most improtant technologies in machining. In this study, the feasibility in applying acoustic emission(AE) signals for the in-process detection of endmill wear and fracture has been investigated by performing experimental test on the NC vertical milling machine with SM45C for specimen. As the results of detecting and analyzing AE signals on various cutting conditions, the followings have confirmed. (1) The RMS value of acoustic emission is related sensitively to the cutting velocity, but is not affected largely by feed rate. (2) The burst type AE signals of high level have been observed when removing chips distorderly and discontinuously. (3) When the RMS value grows up rapidly due to the increase of wear the endmill are generally broken or fractured, but when the endmills fracture at the conditions of smooth chip-flow or built-up-edge(BUE) occurred frequently, the rapid change of the RMS arenot found. And it is expected that this technigue will be quite useful for in-process sensing of tool wear and fracture.

• BMB Reports
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• 제30권2호
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• pp.89-94
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• 1997

In this study, during the activation of neutrophil responses by sodium fluoride. involvement of protein tyrosine kinase was studied. Respiratory burst lysosomal enzyme release and elevation of $[Ca^{2+}]_i$stimulated by sodium fluoride in neutrophils were inhibited by protein kinase inhibitors, genistein and tyrphostin. The inhibitory effect of genistein and tyrphostin on superoxide and $H_{2}O_{2}$ production was less than that of protein kinase C inhibitors, staurosporine and H-7. Staurosporine and H-7 had little or no effect on the release of myeloperoxidase and acid phosphatase stimulated by sodium fluoride. EGTA and verapamil inhibited the elevation of $[Ca^{2+}]_i$ evoked by sodium fluoride. The inhibitory effect of staurosporine on the elevation of $[Ca^{2+}]_i$ was less than that of genistein. Phorbol 12-myristate 13-acetate (PMA)-stimulated superoxide production, which is sensitive to staurosporine, was further enhanced by genistein, whereas the stimulatory action of PMA on myeloperoxidase release was inhibited by genistein. A pretreatment of neutrophils with PMA signifcantly attenuated sodium fluoride-evoked elevation of $[Ca^{2+}]_i$ These results suggest that protein tyrosine kinase may be involved in the activation process of neutrophil responses due to direct stimulation of guanine nucleotide regulatory proteins. In neutrophil responses, PMA-stimulated neutrophils appear to show a different type of inhibition of protein tyrosine kinase.

• 펄프종이기술
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• 제41권4호
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• pp.65-72
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• 2009

We investigated the effect of polyelectrolyte types in Layer-by-Layer multilayering and furnish combination on physical properties of paper. Handsheets were made from pulp fibers with different polyelectrolytes composition, and their density, formation, tensile strength, strain, tear strength and burst strength were evaluated. The density of handsheet was slightly decreased by polyelectrolyte multilayering. Formation did not show a significant change, but all mechanical properties were increased by polyelectrolyte multilayering. Remarkable improvement in tensile and tear strengths was obtained when pulp fibers were treated with cationic starch and poly styrene 4-sulfonate. Irrespectively of final ionicity of pulp fiber, tensile index, strain and tear strength of paper could be improved simultaneously by polyelectrolyte multilayering.

• 한국압력기기공학회 논문집
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• 제5권2호
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• pp.20-26
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• 2009

The dominant incidents category for onshore and offshore natural gas transmission pipelines in the world is associated with outside forces. Incidents in the outside forces category embrace acts of nature, which typically cause widespread structural damage, as well as act of man, whose effects tend to cause dents and/or gouges localized at point of contact that are referred to as mechanical damage. Therefore, these damage types must be better addressed to avoid unnecessary and costly repairs and the possibility of catastrophic events. First of all, the characterizing features of mechanical damage in gas pipelines were evaluated by using of excavator or boring machine. There is no reliable method for evaluating the safe operating pressure of pipeline affected by mechanical damage. It is especially important to evaluate the remaining strength of damaged pipelines due to outside force. Therefore, the full scale burst tests were conducted to evaluate the remaining strength of pipe with mechanical damage that combines a dent and a gouge. This paper is supposed to provide information that will assist in developing a criterion to assess serviceability in pipelines with mechanical damage.

• 한국의류산업학회지
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• 제13권6호
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• pp.990-995
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• 2011

This study analyzed the effects of the knit stitch type, fiber composition, and yarn thickness on the mechanical properties of knitted fabric. The results were as follows: The course density was the highest in the case of the rib stitch. On the other hand, the wale density was the highest in the case of the float stitch. The thickness was the highest in the case of the rib stitch. The same results were obtained even for different fiber compositions and yarn thicknesses considered in this study. The burst strength of wool knit fabric was higher than that of A/W knit fabric. The stiffness was the lowest in the case of the plain stitch. The same results were obtained even for different fiber compositions and yarn thicknesses. The pilling properties were excellent for all knit stitches, fiber composition, and yarn thicknesses as pilling degree : 5. The air permeability decreased in the following order : rib > plain > float stitch. The same results were obtained even for different fiber compositions and yarn thicknesses. The heat retention rate decreased in the following order : rib > float > plain stitch. The same results were obtained even for different fiber compositions and yarn thicknesses.

• 천문학회보
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• 제35권2호
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• pp.45.2-45.2
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• 2010

We analyzed onset times of the largest six solar proton events during 1997-2006 of solar cycle 23, as observed at 1AU by two satellites of GOES/SEM (Geostationary Operational Environmental Satellites/the Space Environment Monitor) and SOHO/ERNE (Solar and Heliospheric Observatory/the Energetic and Relativistic Nuclei and Electron). We adopted the time shifted method suggested by Leon Kocharov and determined the path length by Sam Krucker's fitting method. We found some problems of those methods and tried to improve those. In this presentation, we will give details of the energy spectra of the 6 SPE events from the ERNE/HED, and onset time comparison among the SPE, flare, type II burst, and CME.

• Journal of Microbiology and Biotechnology
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• 제2권3호
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• pp.209-214
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• 1992

Serratia marcescens co-cultured with various phytopathogenic fungi, including Rhizopus stolonifer, Helminthosporium allii, Pyricularia oryzae, Fusarium oxysporium and Collectothricom cassiicola, in an LB- agar medium containing 1.5% swollen chitin, significantly inhibitied fungal growth. Fungal hyphae grew rapidly outward from the culture dish center, but the hyphal extensions of the pathogenic fungi were significantly inhibited in a perimetric contact area with S. marcescens. This was especially evident in pathogenic fungi which have a high chitin content in their cell walls. The extracellular chitinase activities of S. marcescens were increased seven fold by the addition of 1.5% swollen chitin to the LB-broth, compared to chitinase activities in a culture medium without chitin. The type of induction was dependent on the various forms of chitin used. When the culture supernatant of S. marcescens or the chitinases of Streptomyces griceus purchased from Sigma Chemical Co., were incubated with the mycelium of F. oxysporium, the mycelium gradually burst as cultivation time progressed and completely lysed after incubation for 2 days. On the other hand, E. coli extract did not hydrolyze the F. oxysporium mycelium at all. These data showed that the chitinolytic activities of S. marcescens play important roles in the biochemical control of phytopathogenic fungi.