• The Microorganisms and Industry
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• v.19 no.3
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• pp.41-45
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• 1993

The cultural conditions of the osmophilic red color yeasts (Strain L$_{1}$, L$_{2}$, L$_{3}$ and L$_{4}$) isolated and identified in the previous report were examined and the results obtained were as follows ; 1. The optimum medium for growth of these osmophilic red color yeasts was soy sauce medium. 2. These strains were grown exceedingly well on the medium containing 3 percent of NaCl but somewhat restrained on the medium containing 6% or more. 3. The optimum temperautre for growth of these strains was 25.deg.C and their lethal temperature was 68.deg.C(treatment for 5 minutes). 4. The optimum pH for growth of these strains was 6.0.

• The Journal of the Korean dental association
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• v.14 no.12
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• pp.941-943
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• 1976

The author performed the mearsurement of Korean male aging 20 to 25 years, at right and left molar teeth using statham strain gauge and RS Dymograph of Beckman. The conclusion obtained are as follow. 1. The maximum bite force at the thickness 20mm. of Korean male teeth was 27.58kg. 2.The minimum bite force at the thickness 20mm. of Korean male was 23.25kg. 3. The bite force on tje right side was stronger than the left side in average score. 4. The bite force on the left side were stronger than the right in 40 percent of the cases.

• Korean Journal of Veterinary Research
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• v.18 no.1
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• pp.15-18
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• 1978

Ten strains of Salmonella were isolated from feces and lymph nodes of swine slaughtered at Daegu slaughter-house and the rate of isolation was 6.0 percent. Nine strains of Salmonella were isolated by enrichment in selenite F broth and one strain by direct culture on SS agar, but none of Salmonella were isolated from MacConkey ager and in SS broth. Among Salmonella isolated, Salmonella typhimurium occupied over half (6 strains) and the importance of Salmonella in swine for the incidence of food poisoning in man was discussed.

• Structural Engineering and Mechanics
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• v.62 no.5
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• pp.551-565
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• 2017

Based on the strain gradient theory (SGT), vibration analysis of an embedded micro cylindrical shell reinforced with agglomerated carbon nanotubes (CNTs) is investigated. The elastic medium is simulated by the orthotropic Pasternak foundation. The structure is subjected to magnetic field in the axial direction. For obtaining the equivalent material properties of structure and considering agglomeration effects, the Mori-Tanaka model is applied. The motion equations are derived on the basis of Mindlin cylindrical shell theory, energy method and Hamilton's principal. Differential quadrature method (DQM) is proposed to evaluate the frequency of system for different boundary conditions. The effects of different parameters such as CNTs volume percent, agglomeration of CNTs, elastic medium, magnetic field, boundary conditions, length to radius ratio and small scale parameter are shown on the frequency of the structure. The results indicate that the effect of CNTs agglomeration plays an important role in the frequency of system so that considering agglomeration leads to lower frequency. Furthermore, the frequency of structure increases with enhancing the small scale parameter.

• Journal of Advanced Marine Engineering and Technology
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• v.24 no.4
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• pp.460-469
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• 2000

A study on the corrosion behavior of RE36 steel for marine structure was investigated with parameters such as micro-Vickers hardness, corrosion potential and corrosion current density measurement of weld metal(WM), base metal (BM) and heat affected zone(HAZ), Al anode generating current and Al anode weight loss quantity in case of cathodic protection. And we carried out slow strain rate test(SSRT) in order to research mechanical properties such as stress at maximum load, percent strain, time to fracture and strain to failure ratio etc and to find out limiting cathodic polarization potential for hydrogen embrittlement with applied cathodic polarization potential. Hardness of HAZ part was the highest among those three parts and also galvanic corrosion susceptibility was the highest in HAZ part among those three parts due to the lowest corrosion potential than other parts. However corrosion current density was the highest in WM part among those three parts. And the optimum cathodic polarization potential showing the best mechanical properties obtained by SSRT method with applied constant cathodic potential was from - 770mV to - 875mV(SCE). However it is suggested that limiting cathodic polarization potential indicating hydrogen embrittlement on the mechanical properties was under - 900mV(SCE).

• Computers and Concrete
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• v.7 no.2
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• pp.191-202
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• 2010

A laboratory investigation was conducted to characterize the constitutive property behavior of Cor-Tuf, an ultra-high-performance composite concrete. Mechanical property tests (hydrostatic compression, unconfined compression (UC), triaxial compression (TXC), unconfined direct pull (DP), uniaxial strain, and uniaxial-strain-load/constant-volumetric-strain tests) were performed on specimens prepared from concrete mixtures with and without steel fibers. From the UC and TXC test results, compression failure surfaces were developed for both sets of specimens. Both failure surfaces exhibited a continuous increase in maximum principal stress difference with increasing confining stress. The DP tests results determined the unconfined tensile strengths of the two mixtures. The tensile strength of each mixture was less than the generally assumed tensile strength for conventional strength concrete, which is 10 percent of the unconfined compressive strength. Both concretes behaved similarly, but Cor-Tuf with steel fibers exhibited slightly greater strength with increased confining pressure, and Cor-Tuf without steel fibers displayed slightly greater compressibility.

• Applied Biological Chemistry
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• v.48 no.3
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• pp.228-232
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• 2005

A yeast strain producing phytase, isolated from a mash of Korean traditional Yakju, was identified as a strain of Saccharomyces cerevisiae and designated as Saccharomyces cerevisiae CY strain. Phytase was produced by CY strain both intracellularly and extracellularly. Total phytase activity by the shaking culture was about two times higher than that of the static culture. The portion of extracellular phytase to total phytase activity ranged between 23 and 49 percent, depending on the glucose concentration in the culture medium. Phytase production was reached at approximately 1 U/ml as total phytase activity and the maximum intracellular phytase activity was 0.17-0.19 U/mg-DCW at late logarithmic growth phase. The optimum reaction pH and temperature of intracellular phytase were 3.5 and $40^{\circ}C$, respectively. Over 95% of the phytate was degraded by growing cells after 36 hours yeast cell culture and about 90% of total phytate was effectively degraded by suspending the whole cell with the biomass of 0.4 mg-DCW/ml-reaction solution after 12 hours degradation reaction.

• Mycobiology
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• v.36 no.4
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• pp.249-254
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• 2008

Minimal growth inhibitory concentrations (MICs) of chitosan acetate (M.W. 60 kDa) on heterotrophic bacteria (strains MK1, S, and R) isolated from the soft-rotten tissues of Neungee mushroom (Sarcodon aspratus) were measured. The slimy substance produced by the MK1 strain was responsible for the diseased mushroom’s appearance. The S and R strains were members of the Burkholderia cepacia complex. These strains showed different levels of susceptibility toward chitosan acetate. The MIC of chitosan acetate against the MK1 and S strains was 0.06%. The MIC against the R strain was greater than 0.10%. Survival fractions of the MK1 and S strains at the MIC were $3\;{\times}\;10^{-4}$ and $1.4\;{\times}\;10^{-3}$ after 24 h, and $2\;{\times}\;10^{-4}$ and $7\;{\times}\;10^{-4}$ after 48 h, respectively. Survival fractions of the R strain after 24 and 48 hr at 0.1% chitosan acetate were $1\;{\times}\;10^{-2}$ and $6.9\;{\times}\;10^{-3}$, respectively. Compared to the MK1 and S strains, the low susceptibility of the R stain towards chitosan acetate could be due to the ability of the R strain to utilize chitosan as a carbon source. Thirty-eight percent of Neungee pieces treated in a 0.06% chitosan acetate solution for $2{\sim}3$ second did not show any bacterial growth at 4 days, whereas bacterial growth around untreated mushroom pieces occurred within 2 days. These data suggest that chitosan acetate is highly effective in controlling growth of indigenous microorganisms on Neungee. The scanning electron micrographs of the MK1 strain treated with chitosan revealed a higher degree of disintegrated and distorted cellular structures.

• Geotechnical Engineering
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• v.12 no.3
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• pp.17-34
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• 1996

The objective of this paper is to evaluate the asphalt mixture performance with pyrolyzed carbon black(CBP) and air -cooled iron blast furnace slag. Marshall mix design was performed to determine the optimum binder content, The optimum binder content ranged from 6.3 percent to 7.75 percent. Dynamic creep testing was carried out using mixtures at the optimum binder content. Based on the test results, the use of pyrolyzed carbon black and slag in the asphalt pavement showed a positive result, such as the increase of Marshall stability, the decrease of the strain rate and the decrease in the mix stiffness rate at high temperature(5$0^{\circ}C$) and 137.9 kPa confinement. Within the limits of this research. it was concluded that pyrolyzed carbon black as an additive and slag as a coarse aggregate could be used to produce an asphalt paving mixture that has good stability, stiffness, and rutting resistance.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.7 no.1
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• pp.83-92
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• 1987

Fatigue fracture of reinforced concrete structures are characterized by considerably larger strains and microcracking as compared to fracture of R.C. structures under static loading. The strain of stirrup is increased suddenly by the occuring of inclined crack and the average strain ${\epsilon}_{\omega}$ of all stirrups in a structure at maximum load increase approximately in proportion to log N. The structures critical in longitudinal reinforcement seemed to have an endurance limit of 60~70 percent of static ultimate strengths for 1,000,000 cycles. In this test, the average fatigue strength at 1,000,000 cycles for all structures tested was approximately 65 percent of the static ultimate strength.