• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.537-542
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• 2003

The stress-strain curve of concrete confined with both spiral and carbon fiber sheet(CFS) is different to that of concrete confined with only spiral or CFS. The objective of this study is to investigate the stress-strain relation of concrete confined by composite material. In this study, 24 concrete cylinders were tested. The main variable of the cylinders was the content rate of spiral to CFS. The test results indicated that while the compressive strength of cylinder confined with both spiral and CFS increased proportionally to the aided amount of two materials, the maximum strain of cylinder depended on the larger strain of spiral or CFS.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2002.05a
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• pp.159-162
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• 2002

In this paper the stress-strain curves of bearing steels at hot working conditions are obtained by compression test with a computer controlled servo-hydraulic Gleeble 3800 testing machine and elongations and reductions of area of the bearing steels are obtained by tensile test with a computer controlled servo-hydraulic Gleeble 1500 testing machine. These tests have been focused to obtain the flow stress data and optimal hot forging conditions under various conditions of strain rates and temperatures. The strain rate sensitivity exponent and reduction of area of the materials are evaluated. Experimental results are resented for various conditions of temperatures and strain rates.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1996.03a
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• pp.172-184
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• 1996

Superplastic forming of thin sheet into complex shape is an important manufacturing process especially in aerospace industry. The main interest in modeling the superplastic forming process is to predict the forming pressure cycle to maintain optimum strain rate and the resulting thickness distribution. Many researchers have attemped to model superplastic forming using the various techniques including finite element method. But in most of their researches have disregarded the strain hardening effect which which occurs in several superplastic materials. In this study ABAQUS finite element code was used for prediction of process variables for axisymmetric cup forming of Supral 100 and 7075Al alloys considereing strain hardening. The performance of numerical results were compared with the experimental results.

• Pediatric Infection and Vaccine
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• v.23 no.1
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• pp.54-61
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• 2016

Purpose: Bacille Calmette-$Gu{\acute{e}}rin$ (BCG) lymphadenitis is a relatively frequent local adverse reactions after BCG vaccination. Its incidence rate is usually <1%. However, this rate may be different according to BCG strain, vaccination method or skill, etc. In the Republic of Korea, two BCG strains are used: intradermal Danish-1331 or percutaneous Tokyo-172. We surveyed the incidence rates of BCG lymphadenitis. Methods: This survey was performed in total 25 centers (5 general hospitals, 20 private pediatric clinics). Immunized type of BCG strain in study subjects was verified by directly observing the scar. The occurrence of BCG lymphadenitis was asked to their parent. In cases of BCG lymphadenitis, location, diameter size, progression of suppuration, and treatment method were investigated, as well. Results: The total number of study subjects was 3,342. Among these, the subjects suitable for enrollment criteria (total 3,222; Tokyo strain 2,501, Danish strain 721) were analyzed. BCG lymphadenitis regardless of its size developed in each five of subjects per strains, therefore, its incidence rate was 0.20% in Tokyo and 0.69% in Danish strain, respectively (P=0.086). However, when applying the WHO criteria - the development of lymph node swelling with diameter 1.5 cm or more, the incidence rate of BCG lymphadenitis was 0.16% (4 cases) in Tokyo and 0.42% (3 cases) in Danish strain, respectively. Conclusions: The incidence rate of lymphadenitis in two BCG types, percutaneous Tokyo and intradermal Danish strain BCG, is 0.20% and 0.69%, respectively. Both rates are acceptable.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2001.05a
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• pp.83-88
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• 2001

In this study, the tensile and compressive tests of glass fiber epoxy composites were performed to measure the strength variation with respect to strain rates of 1-200 $\textrm{sec}^{-1}$. In addition, tensile and compressive tests of 50-200 $\textrm{sec}^{-1}$ strain rates were conducted at a low temperature ($-60^{\circ}C$) to investigate the effects of temperature on the strength variation. From the test results, it was found that the tensile and compressive strengths increased about 100% and 70%, respectively, at the strain rates of 10-100 $\textrm{sec}^{-1}$ compared to the quasi-static strengths while the strengths were little affected by the environmental temperature variation.

• Mycobiology
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• v.44 no.4
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• pp.283-290
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• 2016

A double-stranded RNA (dsRNA) mycovirus was detected in malformed fruiting bodies of Pleurotus ostreatus strain ASI2792, one of bottle cultivated commercial strains of the edible oyster mushroom. The partial RNA-dependent RNA polymerase (RdRp) gene of the P. ostreatus ASI2792 mycovirus (PoV-ASI2792) was cloned, and a cDNA sequences alignment revealed that the sequence was identical to the RdRp gene of a known PoSV found in the P. ostreatus strain. To investigate the symptoms of PoV-ASI2792 infection by comparing the isogenic virus-free P. ostreatus strains with a virus-infected strain, isogenic virus-cured P. ostreatus strains were obtained by the mycelial fragmentation method for virus curing. The absence of virus was verified with gel electrophoresis after dsRNA-specific virus purification and Northern blot analysis using a partial RdRp cDNA of PoV-ASI2792. The growth rate and mycelial dry weight of virus-infected P. ostreatus strain with PoV-ASI2792 mycovirus were compared to those of three virus-free isogenic strains on 10 different media. The virus-cured strains showed distinctly higher mycelial growth rates and dry weights on all kinds of experimental culture media, with at least a 2.2-fold higher mycelial growth rate on mushroom complete media (MCM) and Hamada media, and a 2.7-fold higher mycelial dry weight on MCM and yeast-malt-glucose agar media than those of the virus-infected strain. These results suggest that the infection of PoV mycovirus has a deleterious effect on the vegetative growth of P. ostreatus.

• Journal of Welding and Joining
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• v.21 no.7
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• pp.49-58
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• 2003

It has been well known that ductile fracture of steel is accelerated by triaxiality stresses. The characteristics of ductile crack initiation in steels are evaluate quantitatively using two-parameter criterion based on equivalent plastic strain and stress triaxiality. Recently, the characteristics of critical crack initiation of steels are quantitatively estimated using the two-parameter, that is, equivalent plastic strain and stress triaxiality, criterion. This study is paid to the fundamental clarification of the effect of geometrical heterogeneity and strength mismatching, which can elevate plastic constraint due to heterogeneous plastic straining, and loading rate on critical condition to initiate ductile crack using two-parameter. Then, the crack initiation testing were conducted under static and dynamic loading. To evaluate the stress/strain state in the specimens especially under dynamic loading, thermal elastic-plastic dynamic FE-analysis considering the temperature rise was used. The result showed that the critical global strain to initiate ductile fracture in specimens with strength mismatch under various loading rate cu be estimated based on the local criterion, that is two-parameter criterion obtained on homogeneous specimens under static tension, by mean of FE-analysis taken into account accurately both strength mismatch and dynamic loading effects on stress/strain behavior.

• Korean journal of applied entomology
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• v.43 no.3 s.136
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• pp.233-239
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• 2004

The potential of five entomopathogenic nematodes, Steinernema carpocapsae Pocheon strain, S. logicaudum Nonsan strain, S. glaseri Dongrae strain, Heterorhabditis bacteriophora Hamnyang strain, and Heterorabditis sp. Gyeongsan strain were evaluated as biological control agents against a mushroom fly, Mycophila speyeri in the mushroom, Pleurotus ostreatus cultivation house. Control effect of M. speyeri was significantly different according to nematode species. Heterorhabditis was more effective than Steinernema. H. bacteriophora Hamnyang strain showed the highest control effect representing $49.0\%$ (7 days), $89.5\%$ (14 days) and $89.1\%$ (21 days post-treatment) at the rate of $1\times10^6$ and $46.5\%$ (7 days), $76.6\%$ (14 days) and $85.4\%$ (21 days post-treatment) at the rate of $1.0\times10^5$ Ijs/$1.5 m^2$ in Changnyoung, Gyeongnam, respectively. In Jinju, Gyeongnam, control effects of the sa me species were $54.0\%$ (7 days), $74.5\%$ (14 days), and $79.8\%$ (21 days post-treatment) at the rate of $1\times10^6$ and $49.0\%$ (7 days), $76.6\%$ (14 days), and $61.1\%$ (21 days post-treatment) at the rate of $1.0\times10^5$ Ijs/$1.5 m^2$, respectively.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.2
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• pp.187-193
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• 2008

Biological removal capacities for volatile organic compounds (VOCs) were determined using a yeast strain, Candida tropicalis. In this study, VOCs including toluene, benzene, p-xylene, and styrene as single substrates or mixtures were tested in the batch culture of the yeast strain. In addition, a kinetic model was applied to evaluate substrate interactions between the VOCs. The yeast strain was able to biodegrade each VOC effectively as a growth substrate, implying it could applied to wide range of VOCs. When the yeast strain was subjected to VOCs in mixtures, the biodegradation rate of one substrate were either increased (stimulated) or decreased (inhibited) by the presence of the others. Both benzene and toluene were inhibited by the other VOCs, and substrate interaction parameters estimated in the model indicated that styrene was the strongest inhibitor for the benzene and toluene biodegradation. Meanwhile, the biodegradation of p-xylene and styrene was stimulated by the presence of either benzene or toluene. The biodegradation rate of p-xylene was significantly increased especially by the presence of toluene, and the styrene biodegradation was enhanced greatly by the benzene addition. The results of the substrate interaction by the yeast strain suggest that the biodegradation rates for the VOCs in mixtures should be carefully evaluated. Furthermore, the competitive inhibition coefficient could be applied as a useful index to determine the substrate interaction

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.2
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• pp.190-198
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• 1996

The Neomycin resistant gene in transposon 5 (Tn5) was introduced into a mutant of Bradyrhizobium japonicum RJB 6 $str^rnal^r$ by conjugation. This marked strain was used in coinoculation of soybean with Pseudomonas fluorescens(Ps-3) and Bacillus subtilis(BCAC-4) and in antibiotic treatment of soybean for studying rate of nodule formation and growth promoting effect on soybean plant. When the marked strain RJB 6 $str^rnal^rneo^r$ with Ps-3, BCAC-4, and Ps-3 plus BCAC-4 was coinoculated into two soils, the recovery rate of the marked strain was 8.5, 4.3 and 2.9 percent in soybean cultivated soil, and 10.3. 6.0 and 5.0 percent in soybean uncultivated soil. The best growth promoting effect of coinoculation on soybean plant was found with the marked strain plus Ps-3. When the marked strain was inoculated into soybean with antibiotic treatment, the rate of nodule formation in soybean cultivated soil was between 12.5 and 25.4 percent, while that in soybean uncultivated soil was between 23.7 and 43.2 percent. The highest rate of nodule formation with the marked strain was found in streptomycin 1000 ppm treatment plot.