• The Korean Journal of Pesticide Science
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• v.10 no.2
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• pp.131-137
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• 2006

This experiment was conducted to select prominent microorganisms with a good insecticidal activity among the ten species, which isolated from soil at the near of Chung-buk, Chung-nam, and Gang-won provinces and made protein crystal endotoxin. As a result, GB-413 strain was finally selected, which showed the high insecticidal activity against susceptible diamondback moth (Plutella xylostella), beet army worm (Spodoptera exigua) and tobacco cutworm (Spodoptera litura) as well as resistant diamondback moth strains. By modifying the cultivation process f.g. lowing the glucose concentration at early cultivation stage and adding the carbon after inducing the spores, the percentage of making spore as well as the number of active spore were increased and the time for cultivation and spore forming was reduced without a reduction of insecticidal activity. These results were not only applied successfully for the optimized cultivation process for a fermentation tank containing five tons capacity, but also improved the possibility of mass cultivation for commercial production.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.452-459
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• 2017

In recent years, to reduce self-weight of structural elements, the use of SCP (Steel Concrete Plate) instead of prestressed concrete is increasing. Because SCP has a complicated sectional shape and includes a large number of studs, the use of high-fluidity concrete is required. Therefore, in this study, to prevent the restrained shrinkage behavior by the stud, the effects of using an expansive agent (EA) and shrinkage reducing agent (SRA) were investigated, and the optimal mixture proportions to maximize the filling capacity were determined based on the fine aggregate ratio. The test results indicated that the combined use of EA and SRA exhibited the smallest shrinkage. The ratio of the crushed sand and washed sea sand was determined to be 5:5, and the proper fine aggregate ratio was found to be 55.6%, because when the ratio was too high, a decrease in strength and an increase in shrinkage strain were expected. The high-fluidity concrete effectively filled the large-sized SCP module.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.4
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• pp.111-116
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• 2018

This research examines the drop impact of an external cooling unit package of an air conditioner system. The packaging is composed of a shock-absorbing material, which protects the package contents by absorbing the impact energy and other parts for fixture. Accurate quantification of the impact acceleration experienced by the package contents is necessary to design an effective packaging with minimal volume and sufficient shock absorbing capacity. Explicit time integration was used for the drop impact analyses. A finite element model of the package was constructed, material testing and material model selection were carried out, and sensors for data acquisition were modeled to obtain accurate simulation results. The results were compared with real physical test data. Due to imprecise modeling of the damping, the acceleration and strain values predicted by the simulation were larger than those from physical test. However, the trend of the history data and the peak deceleration value in the direction of impact showed good agreements. Thus, the analysis model and scheme are suitable for the design of an air conditioner cooling unit package.

• Korean Journal of Microbiology
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• v.53 no.3
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• pp.180-192
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• 2017

The purpose of this study is to investigate the antioxidative and antimicrobial activities of sourdough fermented with the lactic acid bacteria (LAB) isolated from sliced radish kimchi. According to 16S rRNA gene sequence analysis, the isolated lactic acid bacteria were categorized as Leuconostoc dextranicum SRK03, Lactobacillus brevis SRK15, Pediococcus halophilus SRK22, Lactobacillus acidophilus SRK30, Lactobacillus plantarum SRK38, Leuconostoc citreum SRK 42, and Lactobacillus delbrueckii SRK60 with sequence similarity of 99%. After fermentation with L. dextranicum SRK03, L. acidophilus SRK30, L. plantarum SRK38 or L. delbrueckii SRK60 and Saccharomyces cerevisiae KCTC 7246 at $30^{\circ}C$ for 24 h LAB and yeast in sourdough were present at levels of $10^9$ and $10^7CFU/g$, respectively. In particular, the titratable acidity and ethanol and exopolysaccharide contents of sourdough fermented with L. dextranicum SRK03 were also significantly (P < 0.05) higher than those of sourdough fermented with L. acidophilus SRK30, L. plantarum SRK38, or L. delbrueckii SRK60. The sourdough fermented with L. dextranicum SRK03 and L. acidophilus SRK30 showed not only good DPPH radical-scavenging capacity but anti-lipid peroxidation activity. In addition, the viable counts of Bacillus cereus ATCC 11778 and Staphylococcus aureus ATCC 6538 in sourdough during storage for 5 days at $25^{\circ}C$ were significantly (P < 0.05) lower than those of pathogenic bacteria in the control group due to the organic acids and bacteriocin produced by L. acidophilus SRK30 strain.

• Journal of the Korea Concrete Institute
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• v.14 no.6
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• pp.892-899
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• 2002

Among the methods for enhancement of load-carrying capacity on flexural concrete member, recently, a concept is being investigated which replaces the steel in a conventional reinforced concrete member with a fiber reinforced polymer(FRP) shell. This study focuses on modeling of the structural behavior of concrete surrounded with FRP shells in flexural bending members. A numerical model of fiber cross-sectional analysis is proposed to predict the stress and deformation state of the FRP shell and concrete. The stress-strain relationship of concrete confined by a FRP shell is formulated to be based on the constitutive law of concrete in multi-axial compressive stress state, in assuming that the compression response is dependent on the radial expansion of the concrete. To describe the FRP shell behavior, equivalent orthotropic properties of in-plane behavior from classical lamination theory are used. The present model is validated to compare with the experiments of 4-point bending tests of FRP shell concrete beam, and has well predicted the moment-curvature relationships of the members, axial and hoop strains in the section, and the enhancement of confinement effect in concrete surrounded by FRP shell.

• Journal of the Earthquake Engineering Society of Korea
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• v.11 no.2 s.54
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• pp.95-104
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• 2007

Three types of high-rise RC building structures having irregularity in the lower two stories were selected as prototypes and were performed nonlinear static analysis by using OpenSees to verify the analysis technique and to investigate the seismic capacity of those buildings. The first one has a symmetrical moment resisting frame (Model 1), the second has an infilled shear wall in the central frame (Model 2), and the third has an infilled shear wall only in one of exterior frames (Model 3). Fiber model, which consists of concrete and reinforcing bar represented from stress-strain relationship, is adapted used for simulate the nonlinearity of members, and MVLEM(Multi vertical linear element model) is used for simulate the behavior of wall. The analytical results are simulate the behavior of piloti stories well, for example, the stiffness and yield farce of piloti stories, the up-lift of wall and the variation of lateral stiffness of column due to the variation of axial forces. Overstrength of Model 2 and Model 3 are about 2 times larger than that of Model 1. The reason of the high oversttrength and ductility of Model 2 and Model 3 is that the conservative design of Model 2 and Model 3, whose beam and column sections are the same as those of Model 1. The ductilities of Model 1 and Model 3 are slightly larger than that of Model 1 and Model 3. Model 1 and Model 3 reached mechanism condition, whereas Model 2 failed to the shear failure of shear wall and the large axial forces in columns due to large overturning moment.

• Parasites, Hosts and Diseases
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• v.48 no.4
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• pp.325-329
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• 2010

Toxoplasma gondii KI-1, a recent new isolate from Korea, shows similar pathogenicity and infectivity to mice compared to the virulent RH strain. To understand characteristics of host immunity, including immune enhancement or suppression, we investigated proliferative responses and phenotypes of spleen cells. In addition, kinetics of IFN-${\gamma}$, a Th1 cytokine, was examined in BALB/c mice up to day 6 post-infection (PI). Intraperitoneal injection of mice with $10^3$ KI-1 tachyzoites induced significant decreases (P < 0.05) in proliferative responses of spleen cells. This occurred at days 2-6 PI even when concanavalin A (con A) was added and when stimulated with KI-1 antigen, suggesting suppression of the immunity. $CD4^+$ T-cells decreased markedly at day 2 PI (P < 0.05), whereas $CD8^+$ T-cells, NK cells, and macrophages did not show significant changes, except a slight, but significant, increase of $CD8^+$ T-cells at day 6 PI. The capacity of splenocytes to produce IFN-${\gamma}$ by con A stimulation dropped significantly at days 2-6 PI. These results demonstrate that intraperitoneal injection of KI-1 tachyzoites can induce immunosuppression during the early stage of infection, as revealed by the decrease of $CD4^+$ T-cells and IFN-${\gamma}$.

• Journal of the Korean Geotechnical Society
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• v.19 no.4
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• pp.235-246
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• 2003

Since the study of Lee et al.(1994) there have been some case studies on the set-up effect of driven piles in Korea country. However, comprehensive examination on the analyses of the set-up effect with various testing data has not been carried out. In particular, the analysis of the influence of soil type and pile shape on the set-up effect has not been reported. It is necessary to analyse the test results of production piles in order to apply the set-up effect of driven piles for the field engineering. In this study some test piling and analyses were performed to give basic information to the piling design as well as the research on the set-up effect in sandy soils. The analyses on the set-up effect were performed with the monitoring data obtained from the high-strain dynamic loading tests. It was shown that the set-up effect of driven piles was not only affected by soil type but also by soil formation history It turned out that the set-up effect in sandy soils was considerable one that should not be ignored in the field, and that the bearing capacity increase of pile is mainly caused by the increase of shaft resistance. It was shown that the set-up effect of closed pile was larger than that of opened pile in clayey soils, while the set-up effect of opened pile was larger than that of closed pile in sandy soils.

• Journal of the Korean Geotechnical Society
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• v.30 no.12
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• pp.51-61
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• 2014

This paper presents an experimental study of the plugging effect on the capacity of open-ended piles installed in sandy soil. Full-scale tests, including dynamic and static axial-compression load tests, were carried out on three instrumented piles with different diameters (508.0, 711.2 and 914.4 mm). To measure the outer and inner shaft resistances acting on the piles, a double-walled system was utilized with instrumented strain gauges on the outside and inside walls of the pile. The results of field tests show that the inner shaft resistance was mostly mobilized at the location between the pile tip and 18-34% of the total plug length. It was found that the soil plugging in the lower portion has influence on the inner shaft resistance. In addition, it can be also demonstrated that the ratio of inner shaft resistance plus annulus load resistance to total resistance decreased with increasing pile diameters. The results of these tests show that the relationship between the degree of plugging and pile diameter is clearly established. Direct observations of the soil plugs were made and used to quantify both the plug length ratio (PLR) and the incremental filling ratio (IFR). Based on this result, it was found that the N value of the standard penetration test (SPT) is highly correlated with the IFR.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.4
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• pp.555-563
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• 2016

Purple rice is a strain of glutaneous rice rich in anthocyanins and ${\gamma}$-oryzanol. Both types of compounds are involved in antioxidant and lipid metabolism of mammals. Three experimental diet types were used which consisted approximately by half either of purple rice, white rice or corn. Diets were fed to $3{\times}10$ pigs growing from about 30 to 100 kg. Meat samples were investigated either as raw or cured loin chops or as smoked bacon produced from the belly. Various physicochemical traits were assessed and data were evaluated by analysis of variance. Traits describing water-holding capacity (drip, thaw, and cooking losses) and tenderness (sensory grading, shear force) of the meat were mostly not significantly affected by the diet type. However, purple rice feeding of pigs resulted in lower fat and cholesterol contents of loin and smoked bacon compared to white rice, but not compared to corn feeding except of the fat content of the loin. The shelf life of the raw loin chops was improved by purple rice as well. In detail, the occurrence of thiobarbituric acid reactive substances after 9 days of chilled storage was three to four times higher in the white rice and corn diets than with purple rice. The n-6:n-3 ratio in the raw loin chops was 9:1 with purple rice and clearly higher with 12:1 with the other diets, meat lipids. Level and kind of effect of purple rice found in raw meat was not always recovered in the cured loin chops and the smoked bacon. Still the impression of flavor and color, as well as overall acceptability were best in the smoked bacon from the purple-rice fed pigs, whereas this effect did not occur in the cured loin chops. These findings suggest that purple rice has a certain, useful, bioactivity in pigs concerning meat quality, but some of these effects are of low practical relevance. Further studies have to show ways how transiency and low recovery in meat products of some of the effects can be counteracted.