• KSBB Journal
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• v.30 no.3
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• pp.132-139
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• 2015

In order to use the symbiotic bacteria from ethomophatogenic nematodes as a biological control agent for agriculture, the cultural condition for maintaining phase I and antifungal activity was investigated. Symbiotic bacteria (SB) 1 stain from nematodes were selected from the three strains isolated from entomopathogenic nematodes. The growth of the SB 1 strain in NB, TSB, TY and YS medium was higher than that of the SB 2 and SB 3 strain. The packed cell volume of the SB 1 strain was reduced in NB medium which showed radical pH change. Phase I of the SB 1 strain was maintained in TSB medium after being stored for 2 weeks at $4^{\circ}C$. Culture broth with the SB 1 strain in TSB medium for 6 days and 7 days showed antifungal activities against Rhizoctonia solani KACC 40142, Botrytis cinerea Pers. KACC 40854, and Botrytis cinerea Pers. KACC 41008. Culture broth with the SB 1 strain in TSB medium containing 100 mM L-proline for 5 days showed antifungal activities against Rhizoctonia solani KACC 40142, and Botrytis cinerea Pers. KACC 40854.

• Korean Journal of Veterinary Research
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• v.55 no.4
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• pp.241-246
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• 2015

To develop a live vaccine strain against fowl typhoid and paratyphoid caused by Salmonella serovar Gallinarum biovar Gallinarum (Salmonella Gallinarum) and Salmonella serovar Enteritidis (Salmonella Enteritidis), respectively, several nalidixic acid resistant mutants were selected from lipopolysaccharide (LPS) rough strains of Salmonella Gallinarum that escaped from fatal infection of a LPS-binding lytic bacteriophage. A non-virulent and immunogenic vaccine strain of Salmonella Gallinarum, SR2-N6, was established through in vivo pathogenicity and protection efficacy tests. SR2-N6 was highly protective against Salmonella Gallinarum and Salmonella Enteritidis and safer than Salmonella Gallinarum vaccine strain SG 9R in the condition of protein-energy malnutrition. Thus, SR2-N6 may be a safe and efficacious vaccine strain to prevent both fowl typhoid and paratyphoid.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.312-315
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• 2002

This paper summarizes the results of a numerical study conducted to analyze the effect of selected process parameters on material flow and thread profile in thread rolling of large diameter blanks. Based on the previous work where a plane strain mode was found to provide a reasonable approximation of the thread rolling process, the effect of varying thread form, friction factor, flow stress, and blank diameter on effective strain and thread height was analyzed using the finite element code DEFORM. This study show that effective strain for flank angle, that blank diameter had important effect on the as-rolled thread while flow stress, friction factor, and crest round of dies had significant impact on effective strain at the thread root and crest and load of thread rolling. While the rate of strain harding was found to have an effect on the crest profile, the results indicate that it is the primary factor responsible for seam formation in rolled threads.

• Journal of Microbiology
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• v.44 no.4
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• pp.432-438
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• 2006

Twelve actinomycete strains were isolated from Egyptian soil. The isolated actinomycete strains were then screened with regard to their potential to generate antibiotics. The most potent of the producer strains was selected and identified. The cultural and physiological characteristics of the strain identified. the strain as a member of the genus Streptomyces. The nucleotide sequence of the 16S rRNA gene (1.5kb) of the most potent strain evidenced a 99% similarity with Streptomyces spp. and S. aureofaciens 16S rRNA genes, and the isolated strain was ultimately identified as Streptomyces sp. MAR01. The extraction of the fermentation broth of this strain resulted in the isolation of one major compound, which was active in vitro against gram-positive, gram-negative representatives and Candida albicans. The chemical structure of this bioactive compound was elucidated based on the spectroscopic data obtained from the application of MS, IR, UV, $^1H$ NMR, $^{13}C$ NMR, and elemental analysis techniques. Via comparison to the reference data in the relevant literature and in the database search, this antibiotic, which had a molecular formula of $C_{19}H_{29}NO_2$ and a molecular weight of 303.44, was determined to differ from those produced by this genus as well as the available known antibiotics. Therefore, this antibiotic was designated Meroparamycin.

• Journal of the Korea Concrete Institute
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• v.22 no.2
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• pp.263-271
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• 2010

The purposes of this study is to verify the fracture characteristic of steel which is manufactured in Korea, subjected to cyclic loading. This investigation deals with the low cycle fatigue behavior of longitudinal reinforcement in reinforced concrete bridge substructure (piles and columns of piers). Eighty-one specimens of longitudinal reinforcement were tested under axial strain controlled reversed cyclic tests with strain amplitudes. The selected test variables are ratio of tension strain to compression strain, yield stress of longitudinal reinforcement, ratio of diameter of longitudinal steel to clear length of longitudinal steel, size of longitudinal steel and strain amplitudes. Low cycle fatigue behavior and low-cycle fatigue life are investigated and discussed in this paper.

• Journal of Microbiology and Biotechnology
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• v.16 no.10
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• pp.1597-1604
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• 2006

To screen for an anti-yeast substance (AYS), many bacteria were isolated from soil and a strain AY2000 was selected. The strain AY2000 was identified as Rahnella aquatilis by morphology, biochemical properties, and 16S r-RNA nucleotide sequence analyses. The strain AY2000 showed anti-yeast activity against Candida albicans and Saccharomyces cerevisiae, whereas R. aquatilis ATCC33071 as a type strain did not show the activity against the yeasts under the same condition. The growth of yeast cell was significantly inhibited by AYS produced by the strain AY2000, as shown by optical density and MTT assay. The minimum inhibitory concentration (MIC) of the AYS against S. cerevisiae and C. albicans at $28^{\circ}C\;was\;20{\mu}g/ml\;and\;60{\mu}g/ml$, respectively. The MIC of AYS against hyphae of C. albicans at $37^{\circ}C\;was\;600{\mu}g/ml$. Scanning electron microscopic analysis revealed that yeast cells treated with AYS had an irregular form with a wrinkled and rough surface.

• Smart Structures and Systems
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• v.21 no.4
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• pp.407-420
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• 2018

In structural health monitoring, it is meaningful to comprehensively utilize accelerometers and strain gauges to obtain the modal information of a structure. In this paper, a modal estimation theory is proposed, in which the displacement modes of the locations without accelerometers can be estimated by the strain modes of selected strain gauge measurements. A two-stage sensor placement method, in which strain gauges are placed together with triaxial accelerometers to obtain more structural displacement mode information, is proposed. In stage one, the initial accelerometer locations are determined through the combined use of the modal assurance criterion and the redundancy information. Due to various practical factors, however, accelerometers cannot be placed at some of the initial accelerometer locations; the displacement mode information of these locations are still in need and the locations without accelerometers are defined as estimated locations. In stage two, the displacement modes of the estimated locations are estimated based on the strain modes of the strain gauge locations, and the quality of the estimation is seen as a criterion to guide the selection of the strain gauge locations. Instead of simply placing a strain gauge at the midpoint of each beam element, the influence of different candidate strain gauge positions on the estimation of displacement modes is also studied. Finally, the modal assurance criterion is utilized to evaluate the performance of the obtained multitype sensor placement. A bridge benchmark structure is used for a numerical investigation to demonstrate the effectiveness of the proposed multitype sensor placement method.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.12
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• pp.1645-1656
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• 2010

This study was conducted to investigate the effects of strain on broiler performance, and age at slaughter and postchilling (PC) aging time on meat quality traits. A total of 500 one-day-old chicks (250 Hubbard classic and 250 Lohman) were reared under commercial conditions. Half of the broiler birds from each strain were slaughtered at 32 days and the other half at 42 days old. At each processing day, 168 carcasses were randomly selected (84 Hubbard and 84 Lohman) and divided into groups of 28 carcasses within each strain, and aged for 0, 4 and 24 h after chilling. Average weekly body weight was comparable between strains. Feed conversion ratio was higher (p<0.05) for the Hubbard strain during the second and third week of age. Initial carcass pH was significantly (p<0.05) affected by age where younger birds (32-d-old) had lower pH values than older (41-d-old) birds. Breast temperature was higher (p<0.001) for Lohman than Hubbard at 0, 2 and 4 h of PC. Younger birds had a lower breast temperature (p<0.001) at all measured times of PC. Thaw loss, cook loss and water holding capacity were not significantly affected by strain, age or aging time. Lohman strain had more tender meat (p<0.05) than Hubbard strain, and tenderness was improved with the increase of broiler age and aging time. Meats from Hubbard were lighter and less red than those from Lohman strain where younger birds had darker color. In conclusion, strain, age at slaughter and PC aging duration are critical to breast meat quality characteristics, and 4 h of aging are required before deboning in order to obtain more tender fillets.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2004.10a
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• pp.38-39
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• 2004

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• Mycobiology
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• v.32 no.1
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• pp.11-16
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• 2004

Winter mushroom, Flammulina velutipes, needs low temperature during its cultivation. To save on farm costs, especially during summer, a strain adaptable to a higher or elevated-temperature must be developed. At the start of breeding program, parental strains which could endure high temperature were obtained. Seuenty four dikaryotic strains were collected and divided into four groups according to the nature of temperature. They also had different fruiting temperature. Finally we selected three brown strains ASI 4048, 4057 and 4072, and collected their spores. These selected strains can germinate even at a high temperature of $32^{\circ}C$, which were dramatically higher than the other strains. Based on these results, the new white strain adapted to mid-temperature by backcross mating was developed. Molecular markers were applied to select white fruitbody producing strains without cultivation. They showed a specific band which co-segregated with brown fruitbody forming strains in $BC_1F_1$ progenies. Selected white strains were tested under several elevated temperature conditions.