• Journal of Korea Foundry Society
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• v.25 no.1
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• pp.30-35
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• 2005

The structures and mechanical property of the unidirectionally solidified Al-Co eutectic alloy were investigated. Al-Co eutectic alloy was unidirectionally solidified with growth rates(R) between I cm/hr and 10 cm/hr in the induction furnace maintaining the thermal gradient (G) at solid-liquid interface, $32^{\circ}C$/cm. The eutectic microstructure was varied with the growth condition(G/R ratio). When the G/R ratio was larger than $8.5{\times}10^{3}^{\circ}C/cm^{2}/sec$, a lamellar structure was formed, But the G/R ratio was smaller than $8.5{\times}10^{3}^{\circ}C/cm^{2}/sec$, a colony structure was formed. It was found that the interlamellar spacing(${\lambda}$) was dependent on the growth rate(R) with the relationship, ${\lambda}^{2}{\cdot}R=constant$. The microhardness of this eutectic alloy increased with increase in the growth rate.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.18 no.2
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• pp.105-118
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• 2015

This study was conducted to obtain proper amount of solid swine manure and poultry manure in the beginning phase of Cornus kousa growth by investigating the initial germination, seedling growth increment, dry weight, chlorophyll content change, body nutrient uptake and chemical changes of soil according to the concentration of solid swine manure and poultry manure fertilization. When treated with solid swine manure and poultry manure, seed germination rate was the highest in the control. However germination rate showed a tendency to decrease when treated with high concentration of swine manure and poultry manure. The survey results of the growth increment were all higher than that of the control. At the 1.0% treatment of both swine and poultry manure, the seedling height growth was highest. Poultry manure treatment made higher result than swine manure treatment at each treatment. Dry weight was the highest at the 1.0% treatment by both swine and poultry manure. Dry amount declined sharply at the 2.0% treatment. Poultry manure was higher in weight than swine manure at every treatment. Chlorophyll content was the highest at the 1.0% treatment by both swine and poultry manure, but declined sharply at the 2.0% treatment. The survey content was higer than that of the control. The amount of nutrients absorbed in the seedling body was generally high at the 1.0% treatment of swine manure and poultry manure. For the planting soil of Cornus kousa the higher concentration of swine manure and poultry manure was, the lower pH became. However, nitrogen, got higher. available phosphoric acid, exchangeable K, Na, and Mg got higher.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.175-175
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• 2003

• Korean Journal of Materials Research
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• v.12 no.10
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• pp.825-830
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• 2002

The growth rate of solid grains in TiC-XC-2vol% and TiC-XC-30vo1% Ni cermets, where X=Zr, W or Mo, was fitted to an equation of the form $d^3$-$do^3$=Kt. The grain growth behavior during liquid phase sintering at 1673K decreased markedly with addition of $Mo_2$C or WC and increased with addition of ZrC. The contiguity ratio was greater in the alloys with smaller growth rate constant and decreased with increasing Ni content in the $TiC-Mo_2$C-Ni cermet. The grain growth mechanism could be explained by the effect of contiguous grain boundaries in restricting the overall grain growth.

• Journal of the Korean institute of surface engineering
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• v.9 no.2
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• pp.1-7
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• 1976

The dissolving and growth kinetics of intermetallic compounds for the reaction between solid iron and molten zinc were studied under nitorgen atmosphere over the temperature range between470$^{\circ}C$ and 680$^{\circ}C$. The rates of dissolution of solid iron into molten zinc were obtained under a static conditon, The amount of dissolution of sold iron and the growth of intermetalic compounds could be determined by means of microscopy. The thickness of intermetallic compound at a given temperature increases with increasing time, whereas for a given time decreases with increasing temperature . The rate of dissolution is controlled by the diffusion process of iron in the effective boundary layer of molten zinc over the temperature range 470$^{\circ}$-530$^{\circ}C$, 570$^{\circ}$-620$^{\circ}C$, and 650$^{\circ}$-665$^{\circ}C$, while by the surface reaction over the range 530$^{\circ}$-570$^{\circ}C$ and 620$^{\circ}$-650$^{\circ}C$.

• Journal of the Korean Ceramic Society
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• v.32 no.2
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• pp.234-238
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• 1995

MgFe2O4 formation, grain growth in Fe2O3, Fe solid-solution limit in MgO for MgO-Fe2O3 mixture were studied by means of investigating the distribution of phases and compositions in reaction area between MgO and Fe2O3. The reaction area at equlibrium was composed with MgO-FexO matrix and MgFe2O4 precipitation, MgFe2O4 was formed by precipitating from MgO-FexO matrix dependent on oxygen partial pressure. Fe contents was exponentially decreased with diffusion distance in MgO single crystal, and thus Fe solid-solution limitation in MgO was about 4mol%. The grain growth rate in Fe2O3 base was increased with Mg contents diffused from MgO single crystal.

• Journal of Korea Foundry Society
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• v.10 no.4
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• pp.309-315
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• 1990

Aluminum alloy matrix composites reinforced by SiC particles were prepared by rheocompocasting, a process which consists of the incoporation and distribution of reinforcement by stirring within a semi-solid alloy. When the volume fraction of SiCp and stirring speed were fixed, the dispersion of SiCp in Al-matrix alloy depended on stirring time and solid volume fraction in slurry. The results were as follows : 1) As a dispersed SiCp during stirring at $647^{\circ}C$ in 6063-Al alloy, SiC was better dispersed than that other temperature, where solid volume fraction was 43% in slurry. 2) When increased solid fraction in slurry, rate of dispersing SiC increased during stirring and porosities decreased in matrix alloy after casting. 3) Inspite of stirring with 800rpm, since solid particles of matrix alloy in slurry joined each other and occured joining growth, so that SiC was not dispersed into solid particle.

• Journal of computational fluids engineering
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• v.5 no.1
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• pp.27-32
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• 2000

This study investigates the problem of phase change from liquid to solid in the inviscid stagnation flow. The instantaneous location of the solid-liquid interface is fixed for all times by a coordinate transformation. Finite difference method is used to obtain the solution of the unsteady problem, and the growth rate of solid and the transient heat transfer from the surfaces of solid are investigated. The transient solution is dependent on the three dimensionless parameters, but the final steady state is determined by only one parameter of temperature ratio/conductivity ratio. It is observed that the instantaneous heat flux at the surface of solid can be obtained with sufficient accuracy by measuring the thickness of the solid or vice versa.

• Journal of Powder Materials
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• v.9 no.3
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• pp.189-198
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• 2002

In this work, transient liquid phase (TLP) bonding of Ni-Cr heat resisted cast alloy (HP) was investigated. And also the behaviors of the solid particles distributed in the interlayer during TLP bonding were investigated. The MBF-60 and solid particles (Ni, Fe, and $Al_2O_3$ powders respectively) added MBF-60 which will be a liquid phase coexisting with solid particles at the bonding temperature were used as insert metal. The effective and sound bonding was possible by spark plasma sinter-bonding due to the differences of electric resistance between base metal and liquid insert layer which creates high temperature region. During the isothermal solidification, $Al_2O_3$ particles and solid particles of liquid phase sintered insert metal have shown no growth, while Ni and Fe particles grow rapidly. In this TLP bonding using the MBF-60 and distributed Fe, Ni particles as insert materials, the whole isothermal solidification process was dominated by the growth rate of the solid particles distributed in the interlayer.

• Korean Journal of Microbiology
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• v.29 no.5
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• pp.314-318
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• 1991

We investigated the effect of Triton X-100 on the growth and morphology of Trichoderma koningii by comparing various parameters representing the frowth of mold in the presence or absence of Triton X-100. The specific growth rate and doubling time of T. koningii were not affected by the addition of 0.05% Triton X-100 in batch culture. However, in the presence of Triton X-100, cultures reached its stationary phase earlier and showed reduced level in total yield of biomass. The addition of Triton X-100 into solid medium also resulted in decrease in the colony radial growth rate and this response was correlated with the formation of mycelia which showed increase in branching and septation in the presence of Triton X-100.