• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2011년도 춘계학술대회 논문집
• /
• pp.421-422
• /
• 2011

• 한국분말재료학회지
• /
• 제11권5호
• /
• pp.421-426
• /
• 2004

The microstructure and mechanical property of hot-pressed $Al_2O_3/Cu$ composites with a different temperature for atmosphere changing from H$_{2}$ to Ar have been studied. When atmosphere-changed from H$_{2}$ to Ar gas at 145$0^{\circ}C$, the hot-pressed composite was characterized by inhomogeneous microstructure and low fracture strength. On the contrary, when atmosphere-changed at low temperature of 110$0^{\circ}C$ the composite showed more homogeneous microstructure, higher fracture strength and smaller deviation in strength. Based on the thermodynamic consideration and microstructural analysis, it was interpreted that the Cu wetting behavior relating to the formation of CuAlO$_{2}$ is probably responsible for strong dependence of microstructure on atmosphere changing temperature. The reason for a strong sensitivity of fracture strength and especially of its deviation to atmosphere changing temperature was explained by the microstructural inhomogeneity and by the role of CuAlO$_{2}$ phase on the interfacial bonding strength.

• Structural Engineering and Mechanics
• /
• 제20권4호
• /
• pp.421-434
• /
• 2005

In this paper, the finite element method is applied to investigate the effect of the lateral boundary in homogenous soil on the seismic response of a superstructure. Some influencing factors are presented and discussed, and several parameters are identified to be important for conducting soil-structure interaction experiments on shaking tables. Numerical results show that the cross-section width L, thickness H, wave propagation velocity and lateral boundaries of soil layer have certain influences on the computational accuracy. The dimensionless parameter L/H is the most significant one among the influencing factors. In other words, a greater depth of soil layer near the foundation should be considered in shaking table tests as the thickness of the soil layer increases, which can be regarded as a linear relationship approximately. It is also found that the wave propagation velocity in soil layer affects the numerical accuracy and it is suggested to consider a greater depth of the soil layer as the wave propagation velocity increases. A numerical study on a soil-structure experimental model with a rubber ring surrounding the soil on a shaking table is also conducted. It is found the rubber ring has great effect on the soil-structure interaction experiments on shaking table. The experimental precision can be improved by reasonably choosing the elastic parameter and width of the rubber ring.

• Geomechanics and Engineering
• /
• 제17권5호
• /
• pp.421-427
• /
• 2019

Coastal erosion is becoming a significant problem in Greece, Bangladesh, and globally. For the prevention and minimization of damage from coastal erosion, combinations of various structures have been used conventionally. However, most of these methods are expensive. Therefore, creating artificial beachrock using local ureolytic bacteria and the MICP (Microbially Induced Carbonate Precipitation) method can be an alternative for coastal erosion protection, as it is a sustainable and eco-friendly biological ground improvement technique. Most research on MICP has been confined to land ureolytic bacteria and limited attention has been paid to coastal ureolytic bacteria for the measurement of urease activity. Subsequently, their various environmental effects have not been investigated. Therefore, for the successful application of MICP to coastal erosion protection, the type of bacteria, bacterial cell concentration, reaction temperature, cell culture duration, carbonate precipitation trend, pH of the media that controls the activity of the urease enzyme, etc., are evaluated. In this study, the effects of temperature, pH, and culture duration, as well as the trend in carbonate precipitation of coastal ureolytic bacteria isolated from two coastal regions in Greece and Bangladesh, were evaluated. The results showed that urease activity of coastal ureolytic bacteria species relies on some environmental parameters that are very important for successful sand solidification. In future, we aim to apply these findings towards the creation of artificial beachrock in combination with a geotextile tube for coastal erosion protection in Mediterranean countries, Bangladesh, and globally, for bio-mediated soil improvement.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2006년도 추계학술대회 논문집
• /
• pp.421-422
• /
• 2006

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2007년도 춘계학술대회 논문집
• /
• pp.421-422
• /
• 2007

• 한국식품과학회지
• /
• 제15권4호
• /
• pp.421-425
• /
• 1983

• Preventive Nutrition and Food Science
• /
• 제7권4호
• /
• pp.421-426
• /
• 2002

In order to obtain basal data for industrial application of inulinase from Bacillus sphaeicus 188-1, its intracellular inulinase was purified by ammonium sulfate fractionation and column chromatography on DEAE-Sephadex A-50 and Sephadex G-100. The enzyme was homogeneous as judged by SDS-polyacrylamide gel electrophoresis, with an apparent molecular weight of 29 kDa. Inulinase activity was optimal at pH 6.5 and 4$0^{\circ}C$. The enzyme activity was significantly inhibited by Cu$^{2＋}$, Cd$^{2＋}$ and Hg$^{2＋}$. The inulinase exhibited an apparent Km value of 0.014% for inulin.

• Bulletin of the Korean Chemical Society
• /
• 제28권3호
• /
• pp.421-426
• /
• 2007

A linking ligand containing sulfur donor atoms in the terminal thiophene rings, 1,2-bis(thiophen-2-ylmethylene) hydrazine (L), was prepared by Schiff-base condensation. Ligand L reacted with [PdCl2(NCPh)2] to produce a molecular Pd compound [PdL2Cl2] (1). On the other hand, it reacted with AgNO3 and AgClO4 to produce a 2-D network [AgL0.5(NO3)] (2) and a 1-D polymer [AgL]ClO4 (3), respectively, whose structures are based on secondary intermolecular forces such as H-bonding, van der Waals interaction, and π-π stacking. Polymer 2 exhibited photoluminescence at room temperature in the solid state.

• 한국식생활문화학회지
• /
• 제29권5호
• /
• pp.421-427
• /
• 2014

This study was conducted to promote the utilization of fish paste added with green laver powder as a food product. The tested concentrations of green laver powder were 0, 3, 5, and 7%. The pH of the samples ranged from 6.71 to 6.90, and moisture content ranged from 70.03 to 70.57%. The L and a values of the samples decreased as the concentration of green laver powder increased and b value increased. Folding test in all test samples showed AA that mean good flexibility. In the texture meter test, hardness, cohesiveness, and springiness increased according to increasing concentration of green laver powder. However, gumminess and brittleness of the fish paste decreased upon addition of green laver powder. In the sensory evaluation, fish paste prepared with 5% green laver powder was preferred over other fish pastes. These results suggest that green laver powder can be applied to fish paste for the purpose of high quality and functionality.