• International Journal of Concrete Structures and Materials
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• v.11 no.1
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• pp.69-84
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• 2017

This paper presents results of an experimental investigation on the behaviour of bond between external glass fibre reinforced polymer reinforcement and concrete exposed to three different environmental conditions, namely, temperature cycles, wet-dry cycles and outdoor environment separately for extended durations. Single shear tests (pull-out test) were conducted to investigate bond strengths (pull-out strengths) of control (unexposed) and exposed specimens. Effect of the exposure conditions on the compressive strength of concrete were also investigated separately to understand the effect of changing concrete compressive strength on the pull-out strength. Based on the comparison of experimental results of exposed specimens to control specimens in terms of bond strengths, failure modes and strain profiles, the most significant degradation of pull-out strength was observed in specimens exposed to outdoor environment, whereas temperature cycles did not cause any deterioration of strength.

• Computers and Concrete
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• v.29 no.5
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• pp.285-301
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• 2022

This study aims at developing a torsional strength model based on a nonlinear analysis method presented in the previous studies. To this end, flexural neutral axis depth of a reinforced concrete section and effective thickness of an idealized thin-walled tube were formulated based on reasonable approximations. In addition, various sectional force components, such as shear, flexure, axial compression, and torsional moment, were considered in estimating torsional strength by addressing a simple and linear strain profile. Existing test results were collected from literature for verifications by comparing with those estimated from the proposed model. On this basis, it can be confirmed that the proposed model can evaluate the torsional strength of RC members subjected to combined loads with a good level of accuracy, and it also well captured inter-related mechanisms between shear, bending moment, axial compression, and torsion.

• Coupled systems mechanics
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• v.11 no.5
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• pp.373-387
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• 2022

In this paper,soil-structure interaction effects on the seismic response of multistory frame structure on raft foundation are numerically analyzed. The foundation soil profile is assumed to consists of a clay layer of variable thicknessresting on bedrock. Amodified plane-strain numerical model isformed in the software Plaxis, and both free vibration analysis, and earthquake analysis for a selected ground motion accelerogram are performed. The behavior of the structure is assumed to be linear elastic with Rayleigh viscous damping included. The behavior of the clay layer is modeled with a Hardening soil model with small strain stiffness. The computed results in terms of fundamental period and structural horizontal displacementsfor the case of fixed base and for different thicknesses of clay layer are presented, compared, and discussed.

• Proceedings of the Korean Vacuum Society Conference
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• 2002.06a
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• pp.162-162
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• 2002

• Journal of the Korean Chemical Society
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• v.51 no.1
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• pp.51-55
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• 2007

The fatty acid composition of thiocyanate utilizing Bacillus brevis isolated from carbonization wastewater was determined by Gas Chromatography and the results were analyzed. In addition to the saturated and unsaturated straight chain fatty acids this B. brevis strain contained a hydroxy fatty acid. The hydroxy fatty acids in general are shown to be interesting chemotaxonomic markers of bacteria. Cyclopropane fatty acids are totally absent in this strain. A comparison of the fatty acid composition of this strain with B-33 and B-34 strains of Bacillus brevis shows that there are deviations among these strains. The deviation in Bacillus brevis could be due to the stress effect of thiocyanate. This result supports that fatty acid synthesis depends highly on the environment.

• The Journal of Korean Society of Virology
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• v.28 no.2
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• pp.139-146
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• 1998

Recombinant polioviruses have been developed by many research groups for use as vaccine vector because poliovirus induces mucosal immunity as well as humoral immunity through oral uptake. We assessed the potential use of poliovirus as a T-cell epitope carrier. Recombinant poliovirus V129 5L was constructed to have a substituted T-helper epitope from the core protein of Hepatitis B virus at neutralization antigenic site 1 on its VP1 capsid protein. The recombinant virus replicated less efficiently than type 1 poliovirus Mahoney strain. The V129 5L formed a little smaller plaques than the Mahoney strain and showed some 1.25 log unit lower titer at the peak in the one-step growth kinetics though it had similar growth profile to that of the Mahoney strain. Since V129 5L recombinant virus was genetically stable even after 24 successive passages in HeLa cells, the antigenic site 1 on VP1 capsid protein was confirmed for its ability of carrying T cell epitope. The genetic stability of V129 5L also indicated that recombinant poliovirus can be successfully utilized for the development of the multivalent vaccines.

• YAKHAK HOEJI
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• v.42 no.2
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• pp.175-180
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• 1998

Bifidobacterium bifidum OFR9 that exhibits acquired resistance to rifampicin and fluoroquinolones was selected by MNNG and multi-step mutation method. To investigate the resistance mechanism to rifampicin in the strain, RNA polymerase from B. bifidum parent strain and rifampicin-resistance OFR9 was partially purified and its sensitivity to rifampicin was assayed. The profile of RNA polymerase preparation of B. bifidum parent and B. bifidum OFR9 is similar to that of E. coli RNA polymerase that includes the basic subunits of ${\beta}$`, ${\beta},\;{\sigma},\;{\alpha}$ but which are a little different in size when they are compared with E. coli RNA polymerase subunits. RNA polymerase isolated from the parent strain was inhibited by 1${\mu}$g/ml rifampicin but that from B. bifidum OFR9 was not affected by 100${\mu}$g/ml concentration of rifampicin. RNA polymerase activity of B. bifidum OFR9 was maintained over 90% through that rifampicin concentration. This result is consistent with MIC values of in vitro test. It can be concluded that the mechanism of rifampicin resistance in B. bifidum OFR9 is due to an alteration of RNA polymerase.

• The Journal of the Korean Society for Microbiology
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• v.22 no.3
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• pp.267-273
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• 1987

In the analysis of plasmid profile obtained by agarose gel electrophoresis, the strain harvoring multiple reference plasmids of known molecular weight were needed to estimate the size of unknown molecular weight plasmids. Six strains of E. coli isolated from clinical specimens carried multiple plasmids and these strains could be available as a reference plasmids harvoring strain. These E. coli strains showed 4 to 9 plasmids of various size ranging 2.5 to 94.3 megadalton (Mdal). The correlation coefficients of linear regression between the relative mobility and molecular weight were 0.99966 to 1.00000. Among them, E. coli KE327 from throat which contained 7 plasm ids as follows: 79 Mdal, 46 Mdal, 33 Mdal(pKY3027 C), 4.9Mdal, 3.8Mdal(pKY3027 E), 3.5Mdal, and 2.7 Mdal. Relative amount of the pKY3027 C was the smallest(7.09%) and that of the pKY3027 E was the largest (24.24%) among the plasmid fractions of E. coli KE327.

• Steel and Composite Structures
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• v.33 no.3
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• pp.463-472
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• 2019

Initial thermo-elastic and steady state creep deformation of a rotating functionally graded simple blade is studied using first-order shear deformation theory. A variable thickness model for cantilever beam has been considered. The blade geometry and loading are defined as functions of length so that one can define his own blade profile and loading using any arbitrary function. The blade is subjected to a transverse distributed load, an inertia body force due to rotation and a distributed temperature field due to a thermal gradient between the tip and the root. All mechanical and thermal properties except Poisson's ratio are assumed to be longitudinally variable based on the volume fraction of reinforcement. The creep behaviour is modelled by Norton's law. Considering creep strains in stress strain relation, Prandtl-Reuss relations, Norton' law and effective stress relation differential equation in term of effective creep strain is established. This differential equation is solved numerically. By effective creep strain, steady state stresses and deflections are obtained. It is concluded that reinforcement particle size and form of distribution of reinforcement has significant effect on the steady state creep behavior of the blade.

• Journal of Microbiology and Biotechnology
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• v.20 no.1
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• pp.15-20
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• 2010

A Gram negative, aerobic, nonspore-forming, straight or curved rod-shaped bacterium, designated Gsoil $317^T$, was isolated from soil of a ginseng field in Pocheon Province (South Korea) and was characterized using a polyphasic approach. Cells were dimorphic, with stalk (or prostheca) and nonmotile or nonstalked and motile, by means of a single polar flagellum. Comparative analysis of 16S rRNA gene sequences revealed that strain Gsoil $317^T$ was most closely related to Caulobacter mirabilis LMG $24261^T$ (97.2%), Caulobacter fusiformis ATCC $15257^T$ (97.1 %), Caulobacter segnis LMG $17158^T$ (97.0%), Caulobacter vibrioides DSM $9893^T$ (96.8%), and Caulobacter henricii ATCC $15253^T$ (96.7%). The sequence similarities to any other recognized species within Alphaproteobacteria were less than 96.0%. The detection of Q-10 as the major respiratory quinone and a fatty acid profile with summed feature 7 ($C_{18:1}\;{\omega}7c$ and/or $C_{18:1}\;{\omega}9t$ and/or $C_{18:1}\;{\omega}12t;$ 56.6%) and $C_{16:0}$ (15.9%) as the major fatty acids supported the affiliation of strain Gsoil $317^T$ to the genus Caulobacter. The G+C content of the genomic DNA was 65.5 mol%. DNA-DNA hybridization experiments showed that the DNA-DNA relatedness values between strain Gsoil $317^T$ and its closest phylogenetic neighbors were below 11%. On the basis of its phenotypic properties and phylogenetic distinctiveness, strain Gsoil $317^T$ should be classified as representing a novel species in the genus Caulobacter, for which the name Caulobacter ginsengisoli sp. novo is proposed. The type strain is Gsoil $317^T$ (=KCTC $12788^T=DSM\;18695^T$).