• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.1
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• pp.86-91
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• 1989

Since most chemicals effect to the non-target organisms, present study was conducted to determine the effects of some herbicides to soybean nodule bacteria(Rhizobium japonicum) in vitro. Selective upland herbicides Alachlor, Linuron, Simazine and nonselective Paraquat were medicated to the YEMA media and survival rate of the bacteria in the medium was measured a week after incubation. Survival of soybean nodule bacteria in the media medicated with recommended concentration 400 ppm of Alachlor and Linuron were decreased significantly by 27.4 ％ and 57.8 ％, respectively. While little effect was observed in Simazine, a marked reduction of survival was observed in 200 ppm of Paraquat. Effects of Alachlor was different with isolates of the nodule bacteria. Isolate I -122 was relatively resistant and I -145 was more sensitive. than other isolates tested. Intermediate K-5 was the most resistant at the recommended dose and the survival dose was drastically reduced with increment of concentration. Nodule formation of the soybean plants was different with the varieties and isolates. The most nodulation was observed in the resistant isolates I -122 and K-S, for which the nodulation might be related with the resistance to the environmental stress factors.

• Korean journal of food and cookery science
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• v.8 no.2
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• pp.155-163
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• 1992

Rhamsan gum produced by Alcaligenes was rheologically characterized, and compared to that of xanthan gum. The rheological properties were derermined from the change in the value of intrinsic viscosity with pH and salt concentration. at the range of pH 2~11 and salt concentration of 0~1.0 M KCl, the intrinsic viscosties of rhanisan gum were in the range of 8.2 to 36.2 dl/g and those of xanthan gum 8.19 to 44 dl/g. In the absence of salt, the intrinsic viscosity of rhamsan gum and Xanthan gum increased as the pH of solution increased up to neutral pH, and then decreased at alkaline pH. The intrinisc viscosities of rhamsan and anthan gum were not affec6ted by the increment of salt concentration. the chain stiffness paramenter for the rhamsan gum was 0.016. The overlap paramoeters of rhamsan and xanthan gum were 0.025 and 0.022 g/dl, respectively. rhamsan and xanthan gum were shear rate dependent or pseudoplastic. The yield stress of rhamsan gum increased slightly, but the shear index decreased as the concentration increased. The apparent viscosityes of rhamsan and xanthan gum decreased as the temperature increased. The salt effect of divalent cations (calcium, magnesium) was lower than monovalent cations (sodium, potassium).

• Journal of the Korean Geosynthetics Society
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• v.2 no.2
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• pp.13-24
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• 2003

This paper presents the results of investigation on the effects of foundation stiffness and surface loading on the performance of soil-reinforced segmental retaining walls using the finite element method of analysis. A parametric study was performed by varying the foundation stiffness and the location of surface loading. The results of the analyses indicate that the wall deformation and reinforcement tensile load tend to increase with decreasing foundation stiffness with little variation in the horizontal and vertical stress distributions at the back and the base of the reinforced soil zone. Also revealed is that the increment of reinforcement tensile load due to the presence of surface load may be significantly over-estimated when using the conventional approach. Furthermore, the external stability should be carefully examined when a surface loading is present just behind the reinforced soil zone. The implications of the findings from this study to current design approaches are discussed in detail.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.25 no.2
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• pp.163-173
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• 2012

This study covers the nonlinear analysis of anchor head for high strength prestressing strand and presents necessary process in improving the performance of anchor head. The surface of wedge for strand is contacted to the surface of the wedge hole on anchor head when it is fitted into the wedge hole, and the contact condition changes according to the level of load applied through the wedge. In order to analyze detailed behavior, nonlinear material model and contact element were used in analysis. It was found from the analysis that the behavior of anchor head is affected by the interaction with the wedge contacted so that the wedge in FE model should have the same figure as the actual object. Circular array of wedge hole presents better stress distribution than layer array even though the small difference in maximum deformation. Increment of thickness of anchor head and distance of wedge hole also improve the performance of anchor head.

• Korean Journal of Food Science and Technology
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• v.37 no.6
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• pp.951-956
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• 2005

Selection of oxygen-tolerant strains and elucidation of their oxygen tolerance mechanism were crucial for effective use of bifidobacteria. Oxygen-tolerant bifidobacteria were able to significantly remove environmental oxygen (oxygen removal activity) as compared to oxygen-sensitive strains. Most oxygen removal activity was inhibited by heat treatment and exposure to extreme pH (2.0) of bifidobacterial cell. NADH oxidase was major enzyme related to oxygen removal activity. Oxygen-tolerant bifidobacteria possessed high NADH peroxidase activity level to detoxify $H_2O_2$ formed from reaction of NADH oxidase. Addition of oxygen to anaerobic culture broth significantly increased activities of HADH oxidase and NADH peroxidase within 1hr and rapid increment of oxygen concentration was prevented. Results showed NADH oxidase and NADH peroxidase of oxygen-tolerant bifidobacteria played important roles in elimination of oxygen and oxygen metabolite $(H_2O_2)$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.6
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• pp.716-722
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• 2003

This study determined the optimum dosage for coagulation reactions of red tide organisms (RTO) using a combination of ignited oyster shell powder (10sp) and loess and examined the electrokinetic and rheological characteristics of their flocs. Two kinds of RTO, Cylindrotheca closterium and Skeletonema costatum, were sampled in Masan Bay and cultured in the laboratory. Coagulation experiments were conducted using various concentrations of IOSP, loess, IOSP+1oess, RTO, and a jar tester RTO cell numbers were counted for both the supernatant and RTO culture solution. The removal rates increased rapidly with increasing IOSP concentrations up to 50 mg/L and loess concentrations up to 800 mg/L. A removal rate of $100\%$ was reached at 400 mg/L of IOSP and 6,400 mg/L of loess. The highest increment $(16.7\%)$ of the rates of coagulation reaction occurred using both IOSP and loess (50+200 mg/L) in comparison with IOSP alone. The rate of coagulation reaction using both IOSP and loess (50+200 mg/L), $90.6\%,$ was similar to employing either IOSP of 150 mg/L or loess of 3,200 mg/L. All of the coagulation liquids for RTO, IOSP (200 mg/L), loess (200 ma/L), and IOSP+1oess (200+200 mg/L) revealed non-Newtonian fluid properties and therefore their shear rate vs. shear stress curves were non-linear. The coagulation liquids revealed elastic body properties at a lower shear rate increasing in the following order: RTO, IOSP (200 mg/L), loess (200 mg/L), and IOSP+1oess (200+200 mg/L. IOSP+1oess (200+200 mg/L) especially demonstrated plastic flow properties at a lower shear rate.

• Journal of the Korean Geotechnical Society
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• v.21 no.7
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• pp.5-12
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• 2005

In order to investigate the strength and deformation anisotropy of compacted decomposed granite soils, a series of unsaturated-drained triaxial compression tests were performed. The sample used in the study was decomposed granite soil from Shimonoseki in Yamaguchi prefecture. The sample had three different angles of the axial (major principal) direction to the sedimentation plane (compaction plane), 0, 45 and 90 degrees. The compression strain of specimens subjected to isotropic compression was strongly influenced by the sedimentation angle. In addition, the time dependence was independent of the sedimentation angle in relation to the deformation behavior during the secondary compression process. The effect of the sedimentation angle on the triaxial compression strength and deformation was clear with low confining stress. Moreover, it was recognized that although the sedimentation angle and preparation methods were different, the dilatancy rate was relative to the increment of strength due to dilatancy. Therefore, it may be concluded that the compacted specimen has anisotropic mechanical properties similar to those of sand with initial fabric anisotropy.

• Journal of Korean Academy of Nursing
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• v.33 no.4
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• pp.510-518
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• 2003

Background. Ischemic heart disease results from athesclerotic changes of the coronary artery. These changes are aggravated by hypercholesterolemia, smoking, obesity, lack of exercise, coronary-prone personality, and stress. Because these risk factors affect not only the prevalence of the ischemic heart disease but also recurrence of the disease, cardiac rehabilitation programs were introduced to help patients with ischemic heart disease reduce risk factors. Diverse cardiac rehabilitation programs are needed to motivate participation in cardiac rehabilitation and to enhance patients' quality of life. Objectives. To examine the effect of a self-efficacy promoting cardiac rehabiltation program on self-efficacy, health behavior and quality of life of patients with ischemic heart disease. Methods. Data were collected from 45 hospitalized ischemic heart disease patients. Medical records were reviewed to obtain demographic and clinical characteristics. Data regarding self-efficacy, health behavior, and quality of life were obtained from interviews using structured questionnaires. The nonequivalent control group non-synchronized design was used to conduct this study. One session of conventional group education was given to patients in the control group while they were in the hospital. Patients in the experimental group participated in a newly developed cardiac rehabilitation program. It focused on strengthening self-efficacy with four self-efficacy sources-performance accomplishment, vicarious experiences, verbal persuasion and physical status using two individualized in-hospital education sessions and four weekly telephone counseling follow-up calls after discharge. Results. Four weeks after discharge, the increment of total self-efficacy score was significantly higher in the experimental group than in the control group (p<.0l). There was also a significant difference in the total quality of life scores increments between the two groups (p<.0l). However, no significant changes were noted in the increments of total health behavior scores between the two groups. Conclusion. A cardiac rehabilitation program focusing on promoting self-efficacy was effective in improving self-efficacy, and quality of life of patients with ischemic heart disease.

• Corrosion Science and Technology
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• v.9 no.6
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• pp.239-246
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• 2010

When galvanized steel strip is produced through a continuous hot-dip galvanizing process, the thickness of the adhered zinc film is controlled by impinging a thin plane nitrogen gas jet. The thickness of the zinc film is generally affected by impinging pressure distribution, its gradient and shearing stress at the steel strip. These factors are influenced by static pressure of gas spraying at air knife nozzle, a nozzle-to-strip distance and strip and a geometric shape of the air knife, as well. At industries, galvanized steel strip is produced by changing static pressure of gas and a distance between the air knife nozzle and strip based on experimental values but remaining a geometric shape of nozzle. Splashing and check-mark strain can generally occur when a distance between the air knife nozzle and strip is too short, while ability of zinc removal can lower due to pressure loss of impinging jet when a distance between the air knife nozzle and strip is too long. In present study, buckling of the jet and change of static pressure are observed by analyzing flow characteristics of the impinging jet. The distance from the nozzle exit to the strip varies from 6 mm to 16 mm by an increment of 2 mm. Moreover, final coating thickness with change of a distance between the air knife nozzle and strip is compared with each case. An ability of zinc removal with the various distances is predicted by numerically calculating the final coating thickness.

• Journal of Ginseng Research
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• v.19 no.1
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• pp.62-72
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• 1995

During the controlled atmosphere storage (CA), fresh ginseng showed good appearance in quality, and other deterioration of freshness was not observed until 12 weeks. On the other hand, MA storage had kept freshness only in treatment of 1 until 8 weeks. There was no significant difference between treated and non-treated sample with preservatives, and not treated sample was not infected with various different fungi. Moisture contents and hardness of ginseng in all treatments were not changed much until 12 weeks, and surface shrinkage did not occur either. But shear stress increased somewhat in all treatments after 12 weeks. The granule of microstructure in tissue diminished slightly. The apparent Quality of red ginseng was good until 4 weeks of treatment. But as time passed, white skin and wrinkled skin were generated and darkened in its color. B-1 in CA and E-1 in MA were found to be the most favorable one. The content of crude saponin did not change significantly during storage of CA or MA by preservation conditions and period. Though a small increase in saponin content from 4.92% to 5.43% was recognized in B-1, which was treated with preservative and 6.0% In B-2, control, this could rather explain increment of soluble component by butanol. Thus, there was no change in total contents of ginsenoside pattern and composition of each content. The Rbl content in B-1 and B-2 were 0.98%, and 0.97%, respectively, whereas that of control was 0.96%. E-1 of MA, treated with preservative was 5.32% after 12 weeks, but was 5.73% in control, indicating that ginsenosides pattern was quite similar to that of CA storage.