• Journal of the Korea Concrete Institute
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• v.18 no.1 s.91
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• pp.13-19
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• 2006

This paper reports the test results for shrinkage properties of low shrinkage high performance concrete developed by the authors depending on specimen size and constraint of reinforcing bar. As properties in fresh concrete low shrinkage high performance concrete(LSHPC) combined with expansive additives and shrinkage reducing admixture resulted in increase SP dosage due to loss of fluidity compared with that of control mixture concrete, while the dosage of AE agent was decreased. LSHPC exhibited higher compressive and tensile strength than control mixture concrete. For the effect of specimen size, an increase in specimen size led to a reduction of drying shrinkage. However, it was found that the autogenous shrinkage was not affected by the specimen size and measuring method. For constraint condition, an increase in the ratio of reinforcing bar caused the slight reduction in the strain of reinforcing bar, while it increased the autogenous shrinkage stress. It was seen that LSHPC was effective to reduce autogenous shrinkage by as much as 70% compared with control mixture high performance concrete.

• Journal of Life Science
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• v.18 no.2
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• pp.255-263
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• 2008

Bacteria that antagonize plant pathogenic fungi were isolated from the sediment soil at the Ansan industrial estate. One isolate of them showed growth inhibition of Rhizoctonia solani, Botrytis cenerea, and Fusarium oxysporum. This strain was identified as Pandoraea sp. based on phenotypic and phylogenetic characteristics and termed Pandoraea sp. BCNU 315. Tryptone as nitrogen source and sucrose as carbon source were found to be most effective for the microbial growth. In addition, the optimum temperature and pH for microbial growth were $30^{\circ}C$ and pH 7.0, respectively. The substances generated from Pandoraea sp. BCNU 315 were purified and analyzed by column chromatography, HPLC, GC-MS and NMR. As a result, one compound was determined to be indole, another compound was predicted as cyclopentadecaheptene. Detailed structural clarification of the all of the rest six compounds from Pandoraea sp. BCNU 315 has to be accompanied in the further studies.

• Applied Biological Chemistry
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• v.40 no.1
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• pp.65-70
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• 1997

Among 980 fungal strains isolated from the lesions of Trifolium repens L. and various weeds, three Penicillium sp. F40362, F40496, F40497 were selected by the first selection test and a pathogenicity test. The spores of these strains germinated readily 90 to 100% and readily infected the respective plant. The wheat bran-corn starch formulation of F40362 strain showed 100% mycoherbicidal activity against clover plant at $4{\times}10^8$ spores/pot. The same formulations of F40496 and F40497 strains showed 100% mycoherbicidal activity against clover plant at $12{\times}10^8{\sim}4{\times}10^8$ spores/pot. The same formulations of tee strains showed over 30% mycoherbicidal activity against Leguminosae plants. This method of pelletiation was potentially useful for the production of inoculum formulation as mycoherbicides and it was effective enough to treat $2{\sim}2.5\;g$ formulation($4.5{\times}10^7\;spores/mg$) to a $350\;cm^2$ pot. The three strains, F40362, F40496 and F40497 have selective mycoherbicidal activity between Trifolium repens L. and Zoysia japonica and nonselective mycoherbicidal activities against some other crop plants and weeds.

• Journal of the Korean GEO-environmental Society
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• v.9 no.6
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• pp.31-41
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• 2008

Consolidation characteristics of reclamated ground with dredged soil and methods of evaluating them are investigated in this paper. For a dredged and reclamated ground with a very high water content, self-weight consolidation being progressed, its consolidation characteristics are difficult to find since it is almost impossible to have a undisturbed sample. In order to overcome such a problem, methods of laboratory tests with disturbed sample were studied to obtain consolidation parameters required to analyze consolidation settlement in practices, using the conventional infinitesimal consolidation theory, were evaluated by carrying out various laboratory tests with disturbed soils such as oedometer test, constant rate of deformation test, Rowe-cell tests with ring diameters of 60 mm, 100 mm and 150 mm and the centrifuge model tests with 40 g-levels. Constitutive relations of void ratio - effective vertical stress - permeability were evaluated by using the inverse technique implemented with the finite strain consolidation theory and results of centrifuge model tests. Design soil parameters related to consolidation such as compression index, swelling index, coefficient of volume change and vertical and horizontal consolidation coefficients were proposed properly by analyzing the various test results comprehensively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.5
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• pp.939-944
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• 2002

We have screened the microorganisms from pigs feces for the development of probiotics which have acid-and bile-tolerance. Among them, a strain which was identified as Enterococcu durans LP44 was selected. Sixty Duroc$\times$Yorkshire$\times$Landrace pigs (6.30$\pm$0.04 kg average initial body weight) were used in a 14 days growth assay to determine the effects of Enterococco duran Lf44 culture on growth performance of weaned pigs. Dietary treatments included 1) DF (dry feeding),2) W (wet feeding),3) WF+5ED (wet feeding+5% Enterocucu duran LP44 culture),4) WF+ 10ED (wet feeding +10% Enterococcus durans LP44 culture). For overall periods, average daily gain in pigs fed % diet tended to increase compared to pigs fed DF diet without significant difference. Also, there was no significant difference in gain/feed. At 5 days after the onset of the experiment, pigs fed WF+5ED and WF+10ED diets were significantly increased in dry matter and nitrogen digestibilities compared to pigs fed DF and W diets (p<0.05). At 14 days after the onset of the experiment, pigs fed WF+ 10ED diet were significantly increased in dry matter digestibility compared to pigs fed DF diet (p<0.05). Also, pigs fed WF + 10ED diet were significantly increased in nitrogen digestibility compared to other treatments (p<0.05). In conclusion, supplemental Enterococcus durans LP44 was an effective means of improving ADG and nutrient digestibility.

• Journal of Mushroom
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• v.5 no.3_4
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• pp.98-102
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• 2007

Tricholoma gigantium, an edible mushroom, belongs to Tricholomataceae of Tricholoma and is distributed at Jeju-Do in Korea. It is also well-known as the medicinal mushroom in Taiwan. The cultivation method using the compost was developed in Korea in 1995. To develop a mass cultivation method and a superior strain, four strains were collected and tested. To establish the optimal cultivation conditions, various examinations were accomplished. Bag cultivation was more effective than box cultivation and the optimal relative humidity was more than 80%. Although the mycelial growth was tested in the substrate supplemented with different additives, such as rice bran and wheat bran, there's no significant difference between them. It suggested that the environmental conditions were more important than the substrate additives for cultivation.

• Journal of Korean Society of Steel Construction
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• v.25 no.4
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• pp.389-398
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• 2013

The structural provisions of rectangular CFT (concrete-filled tubular) columns in the 2005/2010 AISC Specification, ACI 318-08, and EC4 were comparatively analyzed as a preliminary study for establishing the unified standards for composite structures. The provisions analyzed included those related to the nominal strength, the effect of confinement, plate slenderness, effective flexural stiffness, and the material strength limitations. Small or large difference can be found among the provisions of AISC, ACI, and EC4. Generally, the 2010 AISC Specification provides the revised provisions which reflect up-to-date test results and tries to minimize the conflict with the ACI provisions. For example, the 2010 AISC Specification introduced a more finely divided plate slenderness limits for CFT columns. In seismic applications, the plate slenderness limits required for highly and moderately ductile CFT columns were separately defined. However, the upper cap limitations on material strengths in both the AISC and EC4 provisions are too restrictive and need to be relaxed considering the high-strength material test database currently available. This study found that no provisions reviewed in this paper provide a generally satisfactory method for predicting the P-M interaction strength of CFT columns under various material combinations. It is also emphasized that a practical constitutive model, which can reasonably reflect the stress-strain characteristics of confined concrete of rectangular CFT columns, is urgently needed for a reliable prediction of the P-M interaction strength.

• Journal of the Korean Geotechnical Society
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• v.27 no.2
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• pp.43-52
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• 2011

The characteristics of shear zone in granular soils largely affect the stability of geo-structures. The goal of this study is to evaluate shear zone in a direct shear test using shear wave, electrical resistivity, and cone tip resistance. Bender elements and electrical resistivity probe are embedded into the wall of a direct shear box made of transparent acrylic material to estimate the shear wave velocities and the electrical resistivity at shear and non-shear zones. At the point of peak and residual strength, micro cone penetration test which can be available to measure tip resistance has been performed. Experimental results show that the shear wave velocities at upper shear zone increase during shearing while the values remain constant at bottom and lower shear zone. Also, resistivities at lower shear zone depend on relative density while resistivities at bottom remain constant. The results of cone penetration test demonstrate the correlation of the cone tip resistance and small strain shear modulus at shear zone. This study suggests that the application of the modified direct shear box including shear wave, electrical resistivity and the micro cone tip resistance may become effective tools for analyzing the characteristics of a shear zone.

• Korean Journal of Pharmacognosy
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• v.38 no.2 s.149
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• pp.197-203
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• 2007

Benign prostatic hyperplasia (BPH) is one of the common disease in elderly men. Recently old-age population is increased and we are growing more and more interested in clinical importance of BPH. In this study, the effect of PLX, which was the mixture of tomato extract (including 2% of lycopene) and chitooligosaccharide, on prostatic cancer cell and testosterone-induced BPH in adult rats of the Sprague Dawley strain was determined. The cell viability was evaluated by MTT method using L929 and LNCaP cell line, pretreated with various concentrations of PLX. The expression of prostatic specific antigen (PSA) and 5${\alpha$}$-reductase genes were evaluated by realtime PCR using LNCaP cell line and compared various concentrations of PLX with 50 ${\mu}$M of finasteride. An experimental prostatic hyperplasia was induced in male Sprague Dawley rats by giving testosterone for 8 weeks. After 2 weeks from start of giving testosterone, PLX and finasteride were administered orally once a day. The results were analyzed with prostate weight per body weight at 8 weeks. Cell viability of L929 cell line decreased specifically at the concentration of 2000 ${\mu}$g/mf of PLX. The cytotoxicity of PLX to the LNCaP cell line was shown at above 500 ${\mu}$g/ml of PLX. The inhibitory effect of PLX to the expression of PSA and 5${\alpha$}$-reductase genes in LNCaP cell line increased with the concentration of PLX. In vivo study, the results of PLX and finasteride administered group were 3.75${\pm}$0.60 and 3.49${\pm}$0.49 prostate weight ${\times}10^3$/body weight, which were lower than the result of BPH induced group (4.74${\pm}$0.58). These results suggested that PLX may be an effective material in BPH by having the role of the 5a-reductase inhibitor.

• Korean Journal of Microbiology
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• v.39 no.1
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• pp.21-26
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• 2003

Ninety strains of photosynthetic bacteria were isolated from a local stream at Kyonggi-do, Korea and were further screened. Using these isolated strains, experiments were performed under various light and oxygen conditions in order to select strains with high nitrogen $(NH_3-N,\; NO_3^--N)$ removal efficiencies. Results showed that all the strains screened removed $NH_3-N$, the light had no effect on nitrogen removal, and the nitrogen removal rate was higher aerobically than anaerobically. The removal of $NO_3^--N$ was showed up to 35.3% in some specific strains. Results of batch experiments using Rhodocyclus gelatinosus, an isolated strain with a superior removal rate of $NH_3--N$ and $NH_3-N$, under the anaerobic condition, showed that the removal rate of organics and $NH_3-N$ was the highest (98.2 and 89.0%, respectively) at the CODcr (mg/L)/biomass (mg/L) ratio of 0.2, and the $NH_3-N$ concentration did not increase with the decreasing $NH_3-N$ concentration. Experimental results from various C/N ratios confirmed that the effective removal rate (75.8%) of $NH_3-N$ occurred even at the low (5:1) C/N ratio as well as high ratios, and the simulataneous removal of $NO_3^--N$ (96.0%).