• The Korean Journal of Mycology
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• v.20 no.3
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• pp.229-233
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• 1992

Although there were differences depending on strains and environmental conditions, virus infected oyster mushroom, Pleurotus florida showed slow growth on sawdust and rice straw substrates. Many harmful microorganisms occurred on the cultural bed of virus infected isolates. Pinhead formed too densely or too rarely sometimes. Stipes of the mushrooms were long slightly bent with small cap. The virus infected mushrooms formed branch on their stipes. The first pinheading days of the infeeted mushroom were later than that of healthy culture. The loss of fruit body yield was about 30% compared with that of virus free culture. Spores which contaminated by viruses damaged more seriously than the other source. The authors would like to call these symptoms as a new disease in oyster mushroom culture in the world.

• Applied Biological Chemistry
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• v.27 no.3
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• pp.139-145
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• 1984

For the ultimate manufacture of vinegar with watermelon juice, we examined the preliminarily alcoholic fermentation of watermelon juice using Saccharomyces cerevisiae, Saccharomyces cerevisiae var. ellipsoideus and Kluyveromyces fragilis. The juice contained 3.2% total reducing sugar by the Somogyi-Nelson method. Strains of yeast culture, pH, temperature and concentration of sugar in the juice were important factors affecting alcoholic fermentation. Saccharomyces cerevisiae var. ellipsoideus produced 5.3% alcohol from the juice fortified with 12% glucose under the conditions of pH 5.73 and $27^{\circ}C$ for 8 days. Generally, small quantities of various salts and N-sources affected little the alcoholic fermentation of the juice. The sterilization of the juice by autoclaving improved efficiency of fermentation than that by $SO_2$ sterilization. Determination of alcohol was carried out by the gas chromatographic method using Chromosorb W: Carbowax as packing material.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.766-777
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• 2008

Currently in increasing number of urban tunnels with small overburden are excavated according to the principle of the New Austrian Tunneling Method (NATM). Successful design, construction and maintenance of NATM tunnel demands prediction, control and monitoring of ground displacement and support stress high accuracy. A magnetic anisotropy sensor is used for nondestructive measurement of stress on surfaces of a ferromagnetic material, such as steel. The sensor is built on the principle of the magneto-strictive effect in which changes in magnetic permeability due to deformation of a ferromagnetic material is measured in a nondestructive manner, which then can be translated into the absolute values of stresses existing on the surface of the material. This technique was applied to measure stresses of H-beams, used as tunnel support structures, to confirm expected measurement accuracy with reading error of about 10 to 20 MPa, which was confirmed by monitoring strains released during cutting tests The results show that this method could be one of the promising technologies for non-destructive stress measurement for safe construction and maintenance of underground rock structures encountered in civil and mining engineering.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.1392-1397
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• 2010

Currently in increasing number of urban tunnels with small overburden are excavated according to the principle of the New Austrian Tunneling Method(NATM). Successful design, construction and maintenance of NATM tunnel demands prediction, control and monitoring of ground displacement and support stress high accuracy. A magnetic anisotropy sensor is used for non-destructive measurement of stress on surfaces of a ferromagnetic material, such as steel. The sensor is built on the principle of the magneto-strictive effect in which changes in magnetic permeability due to deformation of a ferromagnetic material is measured in a non-destructive manner, which then can be translated into the absolute values of stresses existing on the surface of the material. This technique was applied to measure stresses of H-beams, used as tunnel support structures, to confirm expected measurement accuracy with reading error of about 10 to 20MPa, which was confirmed by monitoring strains released during cutting tests The results show that this method could be one of the promising technologies for non-destructive stress measurement for safe construction and maintenance of underground rock structures encountered in civil and mining engineering.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.2
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• pp.313-319
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• 2013

This study shows the results of safety analysis obtained from the three different wire rope connections in the RPSD (Rope Platform Screen Door) system, which are the rope connected at both ends, the ropes connected by a pulley at both ends, and the ropes connected by many pulleys at both ends. With a constant load applied, the displacements in the ropes connected by a pulley at both ends and the ropes connected by many pulleys at both ends are smaller than that in the rope connected at both ends. There are no any special different displacements between the ropes connected by a pulley at both ends and the ropes connected by many pulleys at both ends. The displacement in the wire rope diameter of 6mm is smallest of 4.83mm and the strains from the displacements in the ropes connected by a pulley at both ends and the ropes connected by many pulleys at both ends are very small.

• Molecular & Cellular Toxicology
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• v.3 no.1
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• pp.53-59
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• 2007

This study was conducted to evaluate the mutagenic potential of dimethyl isophthalate (DMIP) using Ames bacterial reverse mutation test, chromosomal aberration test and mouse lymphoma $tk^{+/-}$ gene assay. As results, in Ames bacterial reversion assay, DMIP was tested up to the concentration of 5,000 ${\mu}g$/plate and did not induce mutagenicity in Salmonella typhimurium strains TA98, TA100, TA1535 and TA1537, and Escherichia coli WP2uvrA with or without metabolic activation (S9 mix). Using cytotoxicity test, the maximal doses of DMIP for chromosomal aberration assay were determined at 1,250 ${\mu}g/mL$, which was a minimum precipitation concentration ($IC_{50}>1,940\;{\mu}g/mL$ or 10 mM) and at 155 ${\mu}g/mL$ ($IC_{50}:155\;{\mu}g/mL$) in the presence and the absence, respectively, of S9 mix. DMIP in the presence of S9 mix induced statistically significant (P<0.001) increases in the number of cells with chromosome aberrations at the dose levels of over 250 ${\mu}g/mL$, when compared with the negative control. However, DMIP in the absence of S9 mix did not caused significant induction in chromosomal aberrant cells. In MLA, DMIP at the dose range of 242.5-1,940 ${\mu}g/mL$ in the presence of S9 mix induced statistically significant increases in mutation frequencies related to small colony growth, whereas any significant mutation frequency was not observed in absence of S9 mix. From these results, it is conclusively suggested that dimethyl isophthalate may be a clastogen rather than a point mutagen.

• Research in Plant Disease
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• v.9 no.4
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• pp.213-216
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• 2003

A bacterial disease of tea plants(Camellia sinensis L.) was found in the graftage nursery grown under vinyl house conditions in Suncheon city, Korea, in spring of 2002. The primary symptoms of the disease include small, water-soaked and dark brown spot development on the young leaves. This spot gradually increases in size, especially taking on elongate shape along the midrib or vein of the leaf, and then turns black. The diseased leaves were defoliated easily. Ten strains were isolated from the infected leaf. Inoculation on tea leaf with these isolates produced the same symptoms of naturally infected plants. On the basis of stain reactions, morphological characterization, colony pattern, physiological and biochemical reactions, the bacterium was identified as Pseudomonas syringae pv. theae. This is the first report of brown blight of tea plant in Korea.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.5
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• pp.657-664
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• 2013

By using shear mixing and ultrasonication, we fabricated specimens of well-dispersed multi-walled carbon nanotube composites. To confirm the proper dispersion of the filler, we used scanning electron microscopy images for quantitative evaluation and a tensile test for qualitative assessment. Furthermore, the coefficients of thermal expansion of several specimens having different filler contents were calculated from the measured thermal strains and temperatures of the specimens. Based on the microscopy images of the well-dispersed fillers and the small deviations in the measurements of the tensile strength and stiffness, we confirmed the proper dispersion of nanotubes in the epoxy. As the filler contents were increased, the values of tensile strength increased from 58.33 to 68.81 MPa, and those of stiffness increased from 2.93 to 3.27 GPa. At the same time, the coefficients of thermal expansion decreased. This implies better thermal stability of the specimen.

• Food Science of Animal Resources
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• v.36 no.4
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• pp.558-565
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• 2016

The aim of this study was to investigate the influence of proteolytic pork hydrolysate (PPH) on yoghurt production by Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus. Fresh lean pork was cut into pieces and mixed with deionized water and dealt with protease, then the resulting PPH was added to milk to investigate the effects of PPH on yoghurt production. The fermentation time, the viable cell counts, the flavor, free amino acids compounds, and sensory evaluation of yoghurt were evaluated. These results showed that PPH significantly stimulated the growth and acidification of the both bacterial strains. When the content of PPH reached 5% (w/w), the increased acidifying rate occurred, which the fermentation time was one hour less than that of the control, a time saving of up to 20% compared with the control. The viable cell counts, the total free amino acids, and the scores of taste, flavor and overall acceptability in PPH-supplemented yoghurt were higher than the control. Furthermore, the contents of some characteristic flavor compounds including acids, alcohols, aldehydes, ketones and esters were richer than the control. We concluded that the constituents of PPH such as small peptide, vitamins, and minerals together to play the stimulatory roles and result in beneficial effect for the yoghurt starter cultures growth.

• Journal of Ginseng Research
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• v.42 no.1
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• pp.57-67
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• 2018

Background: Ginseng contains many small metabolites such as amino acids, fatty acids, carbohydrates, and ginsenosides. However, little is known about the relationships between microorganisms and metabolites during the entire ginseng fermentation process. We investigated metabolic changes during ginseng fermentation according to the inoculation of food-compatible microorganisms. Methods: Gas chromatography mass spectrometry (GC-MS) datasets coupled with the multivariate statistical method for the purpose of latent-information extraction and sample classification were used for the evaluation of ginseng fermentation. Four different starter cultures (Saccharomyces bayanus, Bacillus subtilis, Lactobacillus plantarum, and Leuconostoc mesenteroide) were used for the ginseng extract fermentation. Results: The principal component analysis score plot and heat map showed a clear separation between ginseng extracts fermented with S. bayanus and other strains. The highest levels of fructose, maltose, and galactose in the ginseng extracts were found in ginseng extracts fermented with B. subtilis. The levels of succinic acid and malic acid in the ginseng extract fermented with S. bayanus as well as the levels of lactic acid, malonic acid, and hydroxypruvic acid in the ginseng extract fermented with lactic acid bacteria (L. plantarum and L. mesenteroide) were the highest. In the results of taste features analysis using an electronic tongue, the ginseng extracts fermented with lactic acid bacteria were significantly distinguished from other groups by a high index of sour taste probably due to high lactic acid contents. Conclusion: These results suggest that a metabolomics approach based on GC-MS can be a useful tool to understand ginseng fermentation and evaluate the fermentative characteristics of starter cultures.