• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.1C
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• pp.53-62
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• 2008

A constitutive model, which can simulate the effect of principal stress rotation associated with direct simple shear test, is proposed in this study. The model is based on two mobilized planes. The plastic strains occur from the two mobilized planes, and depend on stress state, and they are added. The first plane is a plane of maximum shear stress, which rotates about the horizontal axis, and the second plane is a horizontal plane which is spatially fixed. The second plane is used to consider the effect of principal stress rotation on simple shear tests under different stress states. The soil skeleton behavior observed in drained simple shear tests is captured in the model. This constitutive model is incorporated into the dynamic coupled stress-flow finite difference program FLAC. The model is first calibrated with drained simple shear tests on loose Fraser River sand. The measured shear stress and volume change are partially induced by principal stress rotation and compared with model calculations. The model is verified by comparing predicted and measured settlements due to rigid footing resting on loose sands. Settlements predicted by the proposed model were very similar to measured settlements. Mohr-Coulomb model can not consider the effect of principal stress rotation and its prediction was only 20% of measured settlements.

• Research in Plant Disease
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• v.29 no.2
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• pp.145-157
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• 2023

Apple grower in the Cheongsong region, Korea has reported the increased loss of apple yield due to severe bitter rot incidence. We noticed that this indience is because the Colletotrichum population has developed resistance to commonly used fungicides. We isolated 39 Colletotrichum isolates from 13 orchards in Cheongsong, and all the isolated Colletotrichum species were identified as C. siamense or C. fructicola. These 39 strains were tested for mycelial growth and conidial germination against 12 fungicides. trifloxystrobin (30-55% in recommended concentrations) was shown lower inhibitory effect on mycelial growth. However, the inhibition of conidial germination was shown higher than mycelial growth (62-100%). Kresoxim-methyl was shown lower inhibitory effect on mycelial growth (29-55%). conidial germination inhibitory effect was shown 51% to 96%. dithianon was shown diversity response to inhibition of mycelial growth (43-100%). Tebuconazole was shown high inhibitory effect on mycelial growth (84-100%) and conidial germination inhibitory effect was shown to be 64 to 100%. metconazole has been found to display with high inhibitory effect on mycelial growth (79-100%) and conidial germination (70-80%). fluazinam was shown to possess high inhibitory effect on mycelial growth (87-100%) and conidial germination (94-100%). This study provides basic information for the effective management of apple bitter rot.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.6A
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• pp.625-639
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• 2009

Experimental and analytical studies are performed on the mechanical behavior of concrete-filled tubular(CFT) truss girders for different f/L ratios. Bending tests are conducted on two CFT truss girder specimens to determine fundamental structural characteristics such as the strength and deformation properties. Nonlinear material models for CFT members subjected to an axial compressive force are compared in this paper by using the nonlinear finite element program, ABAQUS. Previous researchers have proposed several nonlinear stress-strain models of confined concrete. In this study, the nonlinear analyses are performed applying several stress-strain models for confined concrete proposed by Mander, Sakino, Han, Susantha and Ellobody, and the results are compared with the experimental results in terms of load-deflection and load-strain relationships. Based on the comparisons of the load-deflection relationships, the models proposed by Mander and Susantha provide a maximum load about 12.0~13.8% higher and that by Sakino gives a maximum load about 7.6% higher than the experimental results. The models proposed by Han and Ellobody give a maximum load only about 0.2~1.2% higher than the test results, showing the best agreement among the proposed stress-strain models. However, the load-strain relations predicted by the existing models generally provide conservative results exhibiting larger strains than the experimental data.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.6C
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• pp.259-266
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• 2009

The steel pipe of steel-concrete composite piles increases the pile strength and induces the ductile failure by constraining the deformation of the inner concrete. In this research, the numerical models and the related input parameters were analyzed to simulate the axial load-movement relations, which were obtained from the compression loading tests for the cylindrical specimens of the steel pipe, the concrete, and the steel-concrete composite. As the results, the behavior of the steel pipe was simulated by the von-Mises model and that of the concrete by the strain-softening model, which decreases cohesion and dilation angles as the function of plastic strains. In addition, the reinforcing bars in the concrete were simulated by applying the yielding moment and decreasing the sectional area of the bars. The applied numerical models properly simulated the yielding behavior and the reinforcement effect of the steel-concrete composite piles. The parametric study for the real-size piles showed that the material strength of the steel-concrete composite pile increased about 10% for the axial loading and about 20~45% for the horizontal loading due to the reinforcement effect by the surrounding steel pipe pile.

• Journal of Practical Agriculture & Fisheries Research
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• v.21 no.1
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• pp.81-87
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• 2019

The investigation of mycelial growth for artificial cultivation in T. albuminosus determined that within PDA, YM, MEA medium, both KNCAF 9001 and 9002 strains showed the highest mycelial growth in MEA media with 89, 81 mm, respectively, followed by YM, PDA in respected order. Furthermore, optimal mycelial growth of 89 and 77 mm in 9001 and 9002, respectively, at 25 ℃. Mycelial growth rapidly decreased at 30 ℃, but it was confirmed that it survived at 40 ℃. At pH 6, mycelial growth was fast with growth of 89 and 88 mm for both 9001 and 9002, respectively. In the case of 9001, the addition of with cotton seed hull(80%) and rice bran (20%) each other resulted in maximum productivity of 99 mm/10 days. The result differed in order of corn cob(97 mm), oak sawdust(96 mm) and poplar sawdust(93 mm). Ultimately, the result confirmed that addition of rice bran in comparison to bran resulted in higher yield. Even with identical medium component, 9002 showed the same tendency as 9001 but its growth was relatively slower than 9001. The effect of mycelial growth on the moisture content of the medium was best at 101. 94 mm/10 days when the moisture content of 9001 and 9002 was 65%. Mycelial growth rate tended to be slower when the moisture content was higher or lower than 65%.

• Journal of Naturopathy
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• v.8 no.1
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• pp.21-28
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• 2019

Purpose: The purpose of this study was to examine the impact of 12 Lactobacillus strains and four yeast mixed fermentation broth on the blood characteristics of subjects who consumed for eight weeks. Methods: Blood samples taken from the subjects and clinicopathologic blood components examined. Results: In the white blood cell count the mean pre-test value of the experimental group consumed Zen fermentation broth was 5.73×10³ cells/µl, and the mean after-treatment was 5.37×10³ cells/µl, but the difference was not significant. The control group was not significant. In the hemoglobin content, the mean value before the intake of the Zen-test group was 13.58 g/dl, and the consumption after the consumption was 14.77 g/dl, which significantly increased. Albumin content was 4.33 g/dl before intake and 4.36 g/dl after ingestion in the Zen-test group, but it increased without significance. Triglyceride content was 109.8 mg/dl in the Zen-test group and 99.83 mg/dl in the post-test group, but it was not significant. In the LDL-content the mean of the premeasured value was 109 mg/dl in the Zen-test group, and that of the post-test was 97.87 mg/dl, and the difference significantly decreased to 11.13 mg/dl. In the HDL content, the mean value of the pre-test was 51.4 mg/dl in the Zen-test group and 56.87 mg/dl in the post-test. Conclusion: After intake of Zen fermentation broth, mean values of leukocyte, albumin, and triglyceride were not significantly different in the experimental group, but hemoglobin, LDL and HDL were significantly different.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.316-316
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• 2022

Azuki bean is the important bean crop in Korea, and is traditionally used as a filling material for red bean porridge, rice cakes, and bread, as well as for sediment. So far, the National Insititute of Crop Science has developed azuki bean varieties for various uses, such as for sediment, tea, and azuki bean sprouts. Among azuki bean elite lines, 25 strains were used to analyze the correlation between red bean quality characteristics and sediment yield. The crude protein of red beans was 25.0-28.9%, ash content was 3.8-5.3%, and fat was 0.4-1.0%. As for the appearance quality characteristics of azuki bean, one hundred seed weight was 11.1-19.5 g, the length of seed was 6.45-8.49 mm, the width seed was 4.84-6.45 mm, and the withd/lenght ratio was 0.72-0.89. When the azuki bean were boiled, the thickness of the seed coat was 0.14-0.27 mm and the length ratio of seed was 0.65-0.76 mm, showing that the length of seed was slightly larger than the width. The yield of azuki bean sediment was 239-284% for whole red bean paste, and 144-203% for fine azuki bean paste. As a result of analyzing the correlation between the quality characteristics of azuki beans, such as protein, husk and seed weight, and the yield of azuki bean sediment, the yield of whole azuki bean sediment showed a negative correlation with the seed coat thickness and the length ratio of the original grain at -0.62 and -0.45, respectively. The yield of fine sediment showed a negative correlation with the length ratio of whole azuki beans at -0.49, and a positive correlation with that of white beans at 0.41. However, protein and ash content did not show any correlation with sediment yield. In view of the above results, it is thought that it would be better to have a high seed weight or a low width/length ratio of seed to develope azuki bean cultivar for sediment.

• Journal of The Korean Society of Integrative Medicine
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• v.11 no.4
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• pp.125-133
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• 2023

Purpose : This study aimed to analyze the antibacterial activity of Liriope platyphylla ethanol extract (LPEE) against Streptococcus mutans and Porphyromonas gingivalis and to validate its potential for the prevention and treatment of dental caries, gingivitis, and periodontal disease. Methods : To verify the antibacterial effect of L. pulsatilla ethanolic extract (LPEE) against S. mutans and P. gingivalis, the disk diffusion method was used to determine the inhibition zones at concentrations of 50, 100, 200, and 300 mg/㎖. To determine the minimum inhibition concentration (MIC), the final dose of LPEE was .2, .4, .8, 1.6, 2.5, and 5.0 mg/㎖, and the minimum bactericidal concentration (MBC) was determined based on the MIC results. To confirm the growth inhibitory effect of LPEE on both pathogens, the absorbance was measured at 600 nm after each incubation for 0, 3, 6, 12, and 24 hr at concentrations of .8, 1.6, 2.5, and 5.0 mg/㎖. Results : The cytotoxicity of LPEE was evaluated and the cell viability was more than 70 % at 400 mg/㎖. Therefore, concentrations of 50, 100, 200, and 300 mg/㎖ were used in this study. The antimicrobial effect against S. mutans was seen at 100 mg/㎖ and grew in a concentration-dependent manner, while P. gingivalis was effective at 50 mg/㎖ with the dose dependency. The MIC was .8 mg/㎖ for both strains, and the MBC was 1.6 mg/㎖ with the same results. The growth inhibitory effect of LPEE on S. mutans and P. gingivalis was observed, even at low concentrations. Conclusion : The antibacterial effect of LPEE was evaluated through the analysis of MIC, MBC, and growth inhibition effect on S. mutans and P. gingivalis, which suggests LPEE might have the possibility of utilization as a preventive and therapeutic composition for oral diseases.

• Journal of Microbiology and Biotechnology
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• v.33 no.8
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• pp.1023-1029
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• 2023

Biosurfactants reduce surface and interfacial tension due to their amphiphilic properties and are an eco-friendly alternative for chemical surfactants. In this study, a new yeast strain JAF-11 that produces a biosurfactant was selected using drop collapse method, and the properties of the extracts were investigated. The nucleotide sequences of the strain were compared with closely related strains and identified based on the D1/D2 domain of the large subunit ribosomal DNA (LSU) and internal transcribed spacer (ITS) regions. Neodothiora populina CPC 39399^T, the closest species with strain JAF-11, showed a sequence similarity of 97.75% for LSU and 94.27% for ITS, respectively. The result suggests that the strain JAF-11 represents a distinct species that cannot be assigned to any existing genus or species in the family Dothideaceae. Strain JAF-11 produced a biosurfactant reducing the surface tension of water from 72 mN/m to 34.5 mN/m on the sixth day of culture and the result of measuring the critical micelle concentration (CMC) by extracting the crude biosurfactant was found to be 24 mg/l. The molecular weight 502 of the purified biosurfactant was confirmed by measuring the fast atom bombardment mass spectrum. The chemical structure was analyzed by measuring ¹H nuclear magnetic resonance (NMR), ¹³C NMR, and two-dimensional NMRs of the compound. The molecular formula was C₂₆H₄₆O₉, and it was composed of one octanoyl group and two hexanoyl groups to myo-inositol moiety. The new biosurfactant is the first report of a compound produced by a new yeast strain, JAF-11.

• Korean journal of applied entomology
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• v.62 no.4
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• pp.277-285
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• 2023

The onion moth, Acrolepiopsis sapporensis, was monitored in the farms cultivating the welsh onion, Allium fistulosum, using sex pheromone from transplantation to harvest. Two occurrence peaks were observed at early June and late July after the overwintering population. However, the population sizes were varied among different years and the cultivating environments. To effectively control A. sapporensis with microbial pesticides, different Bacillus thuringiensis strains were screened to select B. thuringiensis kurstaki (BtK). To enhance the insecticidal virulence of BtK, the culture broth of Photorhabdus temperata temperata (Ptt) was added to the BtK. This mixture of two entomopathogenic bacteria was called 'BtPlus', which was superior to BtK alone in the insecticidal virulence. The enhanced virulence was explained by the immunosuppressive activity of the secondary metabolites contained in the Ptt extract. The metabolites inhibited both cellular and humoral immune responses of A. sapporensis, resulting in the enhanced virulence of BtK. These results suggest that A. sapporensis occurs in the welsh onion fields and the resulting economic damage would be effectively prevented by BtPlus application.