• Korean Journal of Veterinary Research
• /
• v.38 no.4
• /
• pp.793-802
• /
• 1998

Salmonellosis caused by a number of serotypes of Salmonella is an infectious, acute or chronic, zoonotic disease and characterized by enteritis and diarrhea, septicemia in animal. In these studies we investigated the prevalent serotypes of Salmonella causing animal salmonellosis in Korea and the 71 strains of Salmonella spp. were isolated from materials such as mesenteric lymph nodes, fecal samples from slaughtered animal. With the identification test results, the most prevalent serotypes were, in order, S stanley 31 strains (43.7%), S typhimurium 19 strains (26.8%) and S montevideo 11 strains (15.5%), respectively. And we could establish the method for detection of antibodies to broad variety of Salmonella serotypes. Lipopolysaccharide(LPS) antigen extracted from Salmonella was more sensitive and specific than outer membrane protein antigen from that for detection of Salmonella antibody by using an indirect ELISA. The optimal concentration of antigen was 100ng/ml of LPS, the dilutions of conjugate and serum were 1 : 1,000~2,000 and 1 : 200~400, respectively. The mix LPS-ELISA which was used by mixing LPS from S typhimurium (group B), S choleraesuis (group C) and S enteritidis (group D) were more rapid and effective than that used LPS from individual strain for detection of Salmonella serogroup O4, O7 and O9 antibody at the same time. We could obtain the high values of optical density ($0.73{\pm}0.32$) by mix LPS-ELISA on the farm which had occurred salmonellosis, but very low values of $0.17{\pm}0.06$ on the negative farm of salmonellosis. So, the mix LPS-ELISA may be used to monitor the serological surveillance for the presence of infection with a number of serotypes of Salmonella and would be useful for prevention and control of salmonellosis in animal.

• Journal of the Korean Geotechnical Society
• /
• v.30 no.5
• /
• pp.67-75
• /
• 2014

In this paper, isotropically consolidated drained triaxial compression test device installed with bender elements is used to measure stress, stain, and shear wave velocity, from which the characteristics of shear strength and Poisson'ratio are investigated. The results show that there is a unique relationship between maximum shear modulus determined from shear wave velocity and effective vertical stress at failure, which is defined as the sum of vertical and radial stresses at failure. The correlation is very useful since it is possible to predict the shear strength and internal friction angle from shear wave velocity. In addition, Poisson's ratio is determined from measured axial and volumetric strains. It is demonstrated that the range of measured Poisson's ratio is between 0.15 and 0.6, and increases with the axial strain. The ratios at axial strains smaller than 0.2% corresponds to the range recommended in design codes, which are approximately from 0.3~0.35. However, at axial strains exceeding 1%, the measured ratios are between 0.5 and 0.6. It is therefore shown that use of ratios commonly used in practice will result in pronounced underestimation at large strains.

• Journal of Elementary Mathematics Education in Korea
• /
• v.20 no.4
• /
• pp.695-715
• /
• 2016

This study is on the teaching method for the students who belong to the same school (one, the gifted class, passed gifted education of Science High school ), 1-1, face-to-face learning (two, good students in regular classroom) with a teacher, paired learning teams (4 people, gifted classes), and group lessons (20 people, gifted classes) and using the justification analysis framework tool(PIRSO) of Kim(2010) analyzes the justification element of the students in the group classes regular polygons paper was to explore ways to improve the justification of the folding maps activities. As a result, the width of the largest polygon difficulty level appropriate to the class for gifted elementary school classes but the individual learning style of the 1-1 face-to-face with a teacher or discussion with colleagues and cooperative approach is justified, rather than the material of the study of origami activities it turned out to be more effective in improving the level of justification. Unlike the individual learning activities, the exploration for class is the need to strain in parallel to the student is selected as needed, rather than serial manner was confirmed that it is necessary to clearly present problems even from the beginning. Development of teaching through the implications obtained from this method of reconstruction activities and proposed improvement measures for questioning.

• Journal of the Korea Institute of Building Construction
• /
• v.17 no.2
• /
• pp.175-181
• /
• 2017

The purpose of this study is evaluating the characteristics of tensile strength of UHPC and examining tensile performance of notched specimens by direct tensile test. For test variables, 120, 150, and 180MPa of target design standard strength were aimed at. With general water curing and $90^{\circ}C$ high temperature steam as curing conditions, the properties were reviewed. Overall, it was represented that the specimens of notch-type direct tensile strength concrete was effective in inducing central cracks compared with existing direct tension specimens. Through this, it was judged that data construction with high reliability was possible. Above all, in a graph of direct tensile strength and strain, in the case of steam curing at high temperature, there was great difference of initial tensile strength compared with water curing. As passing of ages, an aspect that the difference gradually decreased was shown. Maximum tensile strength was found to increase steadily with increasing age for all target design strengths in water curing, in the case of steam curing, the tendency to increase significantly due to the initial strength development effect at 7 days of age. The initial crack strength increases with age in case of underwater curing, in the case of steam curing, it was higher than that of water curing in 7 days, while the strength of 28 days was lowered. In this part, it is considered necessary to examine the arrangement condition of the steel fiber.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.6
• /
• pp.693-699
• /
• 2016

In this study, the replacement effects of cementitious materials (fly ash, blast furnace slag, and blended mixtures) were assessed for normal strength concrete with very low shrinkage properties under $350{\mu}{\varepsilon}$ strain using a powder type shrinkage reducing agent. In addition, through mock-up tests of actual size walls restrained with four sides, the shrinkage characteristics using the power type shrinkage reducing agent were measured and the crack reducing ability was assessed. The slump and air contents were measured as the properties of fresh concrete, and the length changes of the prismatic specimens, $100{\times}100{\times}400mm$ in size, were measured for the shrinkage characteristics. To reduce the shrinkage of concrete, the maximum replacing ratio of the fly ash is effective to 20 percent; however, the use of blast furnace slag and ternary mixtures did not reduce the shrinkage.

• Journal of Food Hygiene and Safety
• /
• v.34 no.6
• /
• pp.591-594
• /
• 2019

Some strains of Escherichia coli are categorized as pathogenic bacteria and alternative antimicrobials including bacteriophages for controlling these bacteria have been studied. In this study we screened antimicrobial candidates that present synergistic inhibition of the growth of E. coli DH5α as a model when co-treated with the bacteriophage ECP27 to target the bacteria. As candidates, CaCl₂, lactic acid, and citric acid were tested. CaCl₂ showed a synergistic inhibition against the strain by dose-dependent manner at 6 h of incubation but the viable cell count was recovered at 12 h. However, lactic acid and citric acid at 30 mM concentration showed synergistic inhibitions at 6 h of incubation and cleared the viable cells of E. coli DH5α at 12 h when co-treated with the bacteriophage even though lactic acid or citric acid alone was effective. Therefore, co-treatment using the bacteriophage and organic acids such as lactic acid and citric acid can be a solution for synergistic inhibition of the growth of E. coli.

• Tuberculosis and Respiratory Diseases
• /
• v.59 no.2
• /
• pp.179-185
• /
• 2005

Background : To evaluate the clinical efficacy of pulmonary resection combined with first-line antituberculous drug therapy in patients with well-localized, cavities-containing pulmonary multidrug-resistant tuberculosis (MDR-TB). Method : From February 1998, seventeen patients with well-localized, cavities-containing pulmonary MDR-TB were enrolled and followed prospectively up to December 2004. After radical pulmonary resection, the patients were treated with antituberculous drugs comprising of isoniazid (H), rifampin (R), pyrazinamide (Z), ethambutol (E), and streptomycin (S) (3HERZS/3HERS/6HER). Results : All recovered isolates of M. tuberculosis were resistant to both isoniazid and rifampin, and to a mean of 4.8 antituberculous drugs (range, 2 to 7 drugs). Surgical procedures included lobectomy (13 patients), lobectomy plus segmentectomy (3 patients), and pneumonectomy (1 patient). The median time for postoperative sputum smear and culture conversion was 2 days (range, 1 to 23 days). Fifteen (94%) patients had durable cures (mean follow-up period, 39.0 months). One patient failed to convert her sputum and was successfully switched to second-line therapy; one patient developed active disease again almost 7 years later, likely due to re-infection with a new M. tuberculosis strain. Conclusion : Radical resection combined with administration of first-line antituberculous agents was effective in patients with well-localized, cavities-containing pulmonary MDR-TB.

• Journal of the Korea Concrete Institute
• /
• v.18 no.1 s.91
• /
• pp.13-19
• /
• 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
• /
• v.18 no.2
• /
• pp.255-263
• /
• 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
• /
• v.40 no.1
• /
• pp.65-70
• /
• 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.