• Journal of Microbiology and Biotechnology
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• v.30 no.2
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• pp.237-243
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• 2020

A novel psychrotolerant Psychrobacillus strain PB01, isolated from an Antarctic iceberg, was comparatively analyzed with five related strains. The complete genome of strain PB01 consists of a single circular chromosome (4.3 Mb) and a plasmid (19 Kb). As potential low-temperature adaptation strategies, strain PB01 has four genes encoding cold-shock proteins, two genes encoding DEAD-box RNA helicases, and eight genes encoding transporters for glycine betaine, which can serve as a cryoprotectant, on the genome. The pan-genome structure of the six Psychrobacillus strains suggests that strain PB01 might have evolved to adapt to extreme environments by changing its genome content to gain higher capacity for DNA repair, translation, and membrane transport. Notably, strain PB01 possesses a complete TCA cycle consisting of eight enzymes as well as three additional Helicobacter pylori-type enzymes: ferredoxin-dependent 2-oxoglutarate synthase, succinyl-CoA/acetoacetyl-CoA transferase, and malate/quinone oxidoreductase. The co-existence of the genes for TCA cycle enzymes has also been identified in the other five Psychrobacillus strains.

• Geomechanics and Engineering
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• v.3 no.4
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• pp.323-337
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• 2011

Israel's coastal region consists, mainly, of Pleistocene and Holocene sands with varying degrees of calcareous cementation, known locally as "kurkar". Previous studies of these materials emphasized the difficulty in their geotechnical characterization, due to their extreme variability. Consequently, it is difficult to estimate construction stability, displacements and deformations on, or within these soils. It is suggested that SPT and Menard pressuremeter tests may be used to characterize the properties of these materials. Values of elastic modulus obtained from pressuremeter tests may be used for displacement analyses at different strain levels, while accounting for the geometric dimensions (length/diameter ratio) of the test probe. A relationship was obtained between pressuremeter modulus and SPT blow count, consistent with published data for footing settlements on granular soils. Cohesion values, for a known friction angle, are estimated, by comparing field pressuremeter curves to curves from numerical (finite element or finite difference) analyses. The material analyzed in the paper is shown to be strain-softening, with the initial cohesion degrading to zero on development of plastic shear strains.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.375-380
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• 2000

Experimental and numerical studies were done to investigate seismic performance of slender sheat wall with no boundary confinement. 1/3 scale-specimens that model the plastic region of long slender shear walls subjected to combined axial load and bending moment were rested to investigate strength, ductility, capacity of energy dissipation and strain distribution. The experimental results show that the slender walls fail due to early crushing in the compressive boundary, and then have very low ductility. The measured maximum compressive strain is 0.0021, which is much less then 0.004 being commonly used for estimation of ductility. The experimental results indicates that the maximum compressive strain is not a fixed value but is affected by moment gradient along the shear wall height and distance from neutral axis to the extreme compressive fiber.

• Journal of the Korea Concrete Institute
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• v.12 no.5
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• pp.47-57
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• 2000

Experimental and numerical studies were done to investigate seismic performance of slender shear walls with no boundary confinement that are principal structural members of high0rise bearing wall buildings. 1/3 scale specimens that model the plastic region of long slender shear walls subjected to combined axial load and bending moment were tested to investigate strength, ductility, capacity of energy dissipation, and strain distribution, The experimental results show that the slender shear walls fail due to early crushing in the compressive boundary, and then have very low ductility. The measured maximum compressive strain is 0.0021, much less than 0.004 being commonly used for estimation of ductility. This result indicates that the maximum compressive strain is not a fixed value but is affected by moment gradient along the shear wall height and distance from the neutral axis to the extreme compressive fiber.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2001.11a
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• pp.118-123
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• 2001

The objectives of this research are to verify the structural stability and estimate the resisting performance of Stressed-Arch system during the construction process. Full scale models are taken to obtain the objective shape by the Dynamic Relaxation Method. As a result, it measured more strain than yielding strain at the extreme fiber of top chord member on the crown, but it is shown that members have the sufficiently compressive resisting performance as well as a considerable strain recovery capacity under unloading. Therefore, it is confirmed that Stressed-Arch system apparently have sufficient range of the structural capacity, but it is required that the elasto-plastic behavior of this system must be verified more detailed by numerical analysis and experiments.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.18 no.2
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• pp.50-53
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• 2022

To investigate the validity of the finite element analysis program to assess structural integrity of a spent nuclear fuel transport cask subjected to extreme impact loads, structural integrity of the cask for the case of an aircraft engine collision is evaluated using three FE analysis programs: Autodyn, Speed and ABAQUS explicit version. As a result of all analyses, it is confirmed that no penetration occurred in the cask wall. Even though the different programs are used, it is identified that there are insignificant differences in the FE analysis variables such as von Mises effective stress and equivalent plastic strain among the programs.

• Applied Biological Chemistry
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• v.33 no.3
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• pp.247-251
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• 1990

A bacterial strain which produce a high level of protease was isolated from a commercial salted fish, squid jetkal. This strain was identified as a strain belong to the genus Halobacterium and was found to be extremely halophilic : more than 2.0M of sodium chloride was required for the growth. The protease production by the strain was maximized when grown on Norberg & Hofsten medium containing 4.5M sodium chloride, 1.5% gelatin and 0.4% yeast extract (initial pH 7.0) for 108hrs at $38^{\circ}C$.

• Structural Engineering and Mechanics
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• v.66 no.3
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• pp.305-315
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• 2018

Interaction of lateral loading, combined with axial force needs to be determined with care in reinforced concrete (RC) one-dimensional structural members (1D SMs) such as beam-columns (BCs) and columns. RC 1D SMs under heavy axial loading are known to fail by brittle mode and small lateral displacements. In this paper, a macro element-based algorithm is proposed to analyze the RC 1D SMs under monotonic or cyclic combined loading. The 1D SMs are discretized into macro-elements (MEs) located between the critical sections and the inflection points. The critical sections are discretized into fixed rectangular finite elements (FRFE). The nonlinear behavior of confined and unconfined concretes and steel elements are considered in the proposed algorithm. The proposed algorithm has been validated by the results of experimental tests carried out on full-scale RC structural members. The evolution of ultimate strain at extreme compression fiber of a rectangular RC section for different orientations of lateral loading shows that the ultimate strain decreases with increasing the axial force. In the examined cases, this ultimate strain ranges from 0.0024 to 0.0038. Therefore, the 0.003 value given by ACI-318 code for ultimate strain, is not conservative and valid for the combined load cases with significant values of axial force (i.e. for the axial forces heavier than 70% of the ultimate axial force).

• Journal of Microbiology and Biotechnology
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• v.30 no.7
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• pp.1005-1012
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• 2020

Acid mine drainage (AMD) has been a serious environmental issue that threatens soil and aquatic ecosystems. In this study, an acid-tolerant sulfate-reducing bacterium, strain S4, was isolated from the mud of an AMD storage pond in Vietnam via enrichment in anoxic mineral medium at pH 5. Comparative analyses of sequences of the 16S rRNA gene and dsrB gene involved in sulfate reduction revealed that the isolate belonged to the genus Desulfovibrio, and is most closely related to Desulfovibrio oxamicus (with 99% homology in 16S rDNA sequence and 98% homology in dsrB gene sequence). Denaturing gradient gel electrophoresis (DGGE) analyses of dsrB gene showed that strain S4 represented one of the two most abundant groups developed in the enrichment culture. Notably, strain S4 was capable of reducing sulfate in low pH environments (from 2 and above), and resistance to extremely high concentration of heavy metals (Fe 3,000 mg/l, Zn 100 mg/l, Cu 100 mg/l). In a batch incubation experiment in synthetic AMD with pH 3.5, strain S4 showed strong effects in facilitating growth of a neutrophilic, metal sensitive Desulfovibrio sp. strain SR4H, which was not capable of growing alone in such an environment. Thus, it is postulated that under extreme conditions such as an AMD environment, acid- and metal-tolerant sulfate-reducing bacteria (SRB)-like strain S4 would facilitate the growth of other widely distributed SRB by starting to reduce sulfate at low pH, thus increasing pH and lowering the metal concentration in the environment. Owing to such unique physiological characteristics, strain S4 shows great potential for application in sustainable remediation of AMD.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.5
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• pp.1158-1167
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• 1995

In this study, the dynamic instabilities of a beam, subjected to periodic short impulsive loading, are investigated using simple 2-DoF beam model. The behaviors of beam model whose axial motions are constrained are studied for the case of elastic and elastic-plastic behavior. In the case of elastic behavior, the chaotic responses due to the periodic pulse are identified, and the characteristics of the behavior are analysed by investigating the fractal attractors in the Poincare map. The short-term and long-term responses of the beam are unpredictable because of the extreme sensitivities to parameters, a hallmark of chaotic response. In the case of elastic-plastic behavior, the responses are governed by the plastic strains which occur continuously and irregularly as time increases. Thus the characteristics of the response behavior change continuously due to the plastic strain increments, and are unpredictable as well as the elastic case.