• 한국동물위생학회지
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• 제29권3호
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• pp.297-308
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• 2006

Fowl typhoid (FT) is a septicemic disease caused by Salmonella gallinarum. The purpose of this study was to investigate the antimicrobial resistance and pulsed -field gel electrophoresis (PFGE) patterns of S gallinarum isolated from broiler. During 1999 to 2004, there was isolated a total of 26 strains in liver and spleen. The biochemical characteristics of S gallinarum isolates was nonmotile, no production of $H_2S$, glucose gas, non-fermented rhamnose, indole-negative, fermentation of dulcitol, mannitol, maltose, and ornithine decarboxylase. At antimicrobial susceptibility, all of isolates were susceptible to amoxicillin/clavulanic acid, amikacin, neomycin, kanamycin, and cephalothin. Twenty-six isolates were divided into 19 resistant patterns and 6 strains was 8-multi-drug resistance. PFGE of Xba I restriction fragments of S gallinarum isolates was 22 patterns.

• 한국식품영양과학회지
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• 제30권1호
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• pp.193-195
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• 2001

A radiation-resistant bacterium was isolated from gamma irradiated dried laver (Porphyra tenera) and its microbiological characteristics were examined. As a result of resistance test to gamma irradiation, the isolate was survived $10^{3}$ CFU/mL even at 30 kGy and significant shoulder line zone was shown until 20 kGy. The $D_{10}$ value was 11.27 kGy. The isolate was gram-positive, non-motile coccus and catalase-positive. n culture, the red-pigmented smooth colony was observed. The biochemical test in API (analytical profile index) system showed that the isolate fermented glucose and fructose as the carbon source. Therefore, a radiation-resistant bacterium isolated from laver was potentially identified as Micrococcus roseus sp.

• International Journal of Concrete Structures and Materials
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• 제9권4호
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• pp.439-451
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• 2015

This study analyzed the isolation effect for a 15-story reinforced concrete (RC) building with regard to changes in the beam-column stiffness ratio and the difference in the vibration period between the superstructure and an isolation layer in order to provide basic data that are needed to devise a framework for the design of isolated RC buildings. First, this analytical study proposes to design RC building frames by securing an isolation period that is at least 2.5 times longer than the natural vibration period of a superstructure and configuring a target isolation period that is 3.0 s or longer. To verify the proposed plan, shaking table tests were conducted on a scaled-down model of 15-story RC building installed with laminated rubber bearings. The experimental results indicate that the tested isolated structure, which complied with the proposed conditions, exhibited an almost constant response distribution, verifying that the behavior of the structure improved in terms of usability. The RC building's response to inter-story drift (which causes structural damage) was reduced by about one-third that of a non-isolated structure, thereby confirming that the safety of such a superstructure can be achieved through the building's improved seismic performance.

• Earthquakes and Structures
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• 제7권6호
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• pp.1223-1240
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• 2014

Seismic isolation has been established as an effective earthquake-resistant design method and the lead rubber bearings (LRBs) are among the most commonly used seismic isolation systems. In the scientific literature, a sharp bilinear model is often used for capturing the hysteretic behaviour of the LRBs in the analysis of seismically isolated structures, although the actual behaviour of the LRBs can be more accurately represented utilizing smoothed plasticity, as captured by the Bouc-Wen model. Discrepancies between these two models are quantified in terms of the computed peak relative displacements at the isolation level, as well as the peak inter-storey deflections and the absolute top-floor accelerations, for the case of base-isolated buildings modelled as multi degree-of-freedom systems. Numerical simulations under pulse-like ground motions have been performed to assess the effect of non-linear parameters of the seismic isolation system and characteristics of both the superstructure and the earthquake excitation, on the accuracy of the computed peak structural responses. Through parametric analyses, this paper assesses potential inaccuracies of the computed peak seismic response when the sharp bilinear model is employed for modelling the LRBs instead of the more accurate and smoother Bouc-Wen model.

• 한국응용곤충학회지
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• 제34권3호
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• pp.243-248
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• 1995

효과적인 미생물 제제로 사용할 수 있는 Bacillus thuringiensis 균주들을 분리하기 위하여 경기도 일원의 72군데의 저곡창고에서 먼지를 채취하여 B. thuringiensis의 분포와 독성을 조사하였다. 총 411개의 채취된 저곡창고의 먼지에서 포자와 내독소 단백질을 생산하는 146개에 이르는 많은 수의 B. thuringiensis가 분리되었다. 저곡창고에서 분리된 146개 Bt의 독성 분포는 나비목의 누에 (Bombyx mori)유충에 독성을 띠는 균주가 84%로 가장 많이 분리되었고, 파리목의 빨간 집모기(Culex pipiens)유충에는 3%, 나비목과 파리목에 동시에 독성을 띠는 균주는 1%였다. 그러나 딱정벌레목의 쌀바구미(Sitophitus oryzae)에 독성을 띠는 균주는 분리되지 않았으며, 내독소 단백질은 형성하지만 독성을 띠지 않는 B. thuringiensis가 12%의 비율로 분리되어 흔히 존재함을 알 수 있었다. 이상의 결과로서 저곡창고는 B. thuringiensis의 유리한 분리장소임을 알 수 있었다.

• 식물병연구
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• 제19권2호
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• pp.121-123
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• 2013

사과, 호박, 고추에서 분리된 탄저병균들(Colletotrichum gloeosporioides, C. orbiculare, C. acutatum)이 복분자딸기에 병원성을 나타냈으며. 특히 사과에서 분리된 탄저병균은 무상처 접종에서도 병원성을 나타냈다. 복분자 딸기에서 분리한 탄저병균(Colletotrichum gloeosporioides, C. coccodes, C. acutatum)은 사과와 딸기에서는 dropping 접종에 의해 병원성을 보였으나 고추와 토마토에서는 낮은 병원성을 나타내었다.

• Structural Engineering and Mechanics
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• 제46권5호
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• pp.645-672
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• 2013

The differential settlements and rotations among footings cannot be avoided when the frame-footing-soil system is subjected to seismic/dynamic loading. Also, there may be a situation where column(s) of a building are located near adjoining property line causes eccentric loading on foundation system. The strap beams may be provided to control the rotation of the footings within permissible limits caused due to such eccentric loading. In the present work, the seismic interaction analysis of a three-bay three-storey, space frame-footing-strap beam-soil system is carried out to investigate the interaction behavior using finite element software (ANSYS). The RCC structure and their foundation are assumed to behave in linear manner while the supporting soil mass is treated as nonlinear elastic material. The seismic interaction analyses of space frame-isolated footing-soil and space frame-strap footing-soil systems are carried out to evaluate the forces in the columns. The results indicate that the bending moments of very high magnitude are induced at column bases resting on eccentric footing of frame-isolated footing-soil interaction system. However, use of strap beams controls these moments quite effectively. The soil-structure interaction effect causes significant redistribution of column forces compared to non-interaction analysis. The axial forces in the columns are distributed more uniformly when the interaction effects are considered in the analysis.

• 한국버섯학회지
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• 제15권1호
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• pp.8-13
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• 2017

An auxin-producing bacterial strain, designated 4-3, was isolated from waste button mushroom compost in Boryeong-si, Chungnam. The strain 4-3 was classified as a novel strain of Leucobacter tardus, based on chemotaxonomic and phylogenetic analyses. TLC and HPLC the isolated L. tardus strain 4-3 produced indole-3-acetic acid (IAA), the auxin. Maximum IAA productionof $94.3mg\;L^{-1}$ was detected for bacteria cultured in R2A medium with 0.1% l-tryptophan, incubated for 24 h at $35^{\circ}C$. Negative correlationwas observed between IAA production and pH of the culture medium, indicating that the increase inIAA caused acidification ofthe medium. The effect of supplementation with varying concentrations of l-tryptophan, a known precursor of IAA, was also assessed. production was maximal at 0.1% l, but decreased at lconcentrations above 0.2%. To investigate the plant growth-promoting effects of the bacterium, L. tardus strain 4-3 culture broth was used to inoculate water cultures and seed pots of mung bean. We found thatadventitious root induction and root growth were 2.2-times higher in thethan in the non-inoculated plants.

• 대한기계학회논문집A
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• 제20권1호
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• pp.127-134
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• 1996

In general, seismic isolators which are made of laminated rubber and shim plate have characteristics of complex hysteretic behavior. When shear deformation of the seismic isolator is small, the isolator hassimple hysteretic almost bi-linear behabior. But on large shear deformation hardening effects may occur. This paper proposes a moldeling method of the seimic isolator with modified hysteretic bi-linear model which can consider the hardening effects. From the results of the seismic analyses of the isolated system it is shown that the responses are singificantly reduced compared with those of the non-isolated system. The modified hysteretic bi-linear model of the isolator gives larger ZPA(zero period acceleration) than those of the simple hysteretic bi-linear model and the equivalunt spring-damper model.

• Journal of Microbiology and Biotechnology
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• 제1권2호
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• pp.96-101
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• 1991

Phenotypic changes after plasmid curing experiment suggested that the bacteriocin production phenotype ($Bac^{+}$) might be linked to a chromosomal DNA and the mucin production phenotype ($Muc^{+}$) might be linked to a 62.5 kilobase (kb) plasmid (pMUC62) in Lactobacillus plantarum 27 isolated from meat starter culture. The non-mucoid ($Muc^{-}$) variants were missing pMUC62 but they produced bacteriocin as the wild strain ($Bac^{+}$). There was no difference in antibiotic resistance and sugar fermentation patterns between the wild strain ($Bac^{+}$ $Muc^{+}$) and the nonmucoid ($Bac^{+}$ $Muc^{-}$) variants. Antimicrobial spectrum of bacteriocin produced by both wild strain and $Muc^{-}$ variant of Lb. plantarum 27 included strains of Pediococcus acidilactici (A, M, H), Pediococcus sp. isolated from meat, Lactobacillus sp. isolated from meat, Lb. plantarum NCDO 955 and Staphylococcus aureus 485. Neither of the tested Gram negative bacteria were inhibited by bacteriocin. Antimicrobial activity of crude bacteriocin was retained after autoclaving, DNase or catalase treatment and exposure from pHs 4 to 9 but was lost after treating with several proteolytic enzymes and exposure at pH 10.