• Journal of the Korean Ceramic Society
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• v.40 no.1
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• pp.24-30
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• 2003

A formation and conversion of AFm phases decisively play role in the hydration, hardening and corrosion processes of various cement. In this study, the conversion of Alumino-Ferrite Monohydrates(AFm) phases under the addition of $CaCO_3,;CaCl_2;and;CaSO_4{cdot}2H_2O$was investigated by the XRD quantitative analysis. The thypical AFm phases are $M_S(monosulfoaluminate),;M_C(monocarboaluminate);and;M_{Cl}(monochloroaluminate and also Called Friedel's salts)$in this cementitious system, The conversion reaction were not occurred in $M_C-CaCO_3,;M_{Cl}-CaCO_3$ and $M_{Cl}-CaCl_2$system. However, in $M_S-CaCO_3$ system, ettringite and $monocarboaluminate(M_C)$ were formed. In $M_S-CaCl_2;system;M_S$ was transformed to Friedel's $salts(M_{Cl})$ and ettringite was formed. In the case of $CaSO_4{cdot}2H_2O$ addition, all AFm $phases(M_S,;M_C;and;M_{Cl})$ were transformed to ettringite. The order of stabilization of AFm phases under $CaCO_3,;CaCl_2;and;CaSO_4{cdot}2H_2O$ was as follows : $M_S< M_C

• Journal of Powder Materials
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• v.22 no.3
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• pp.208-215
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• 2015

Fe-TiC composite powders were fabricated by planetary ball mill processing. Two kinds of powder mixtures were prepared from the starting materials of (a) (Fe, TiC) powders and (b) (Fe, $TiH_2$, Carbon) powders, respectively. Milling speed (300, 500 and 700 rpm) and time (1, 2, and 3 h) were varied. For (Fe, $TiH_2$, Carbon) powders, an in situ reaction synthesis of TiC after the planetary ball mill processing was added to obtain a homogeneous distribution of ultrafine TiC particulates in Fe matrix. Powder characteristics such as particle size, size distribution, shape, and mixing homogeneity were investigated.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.9 no.1
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• pp.14-19
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• 1999

Using a single precursor of hexamethyldisilane $(Si_{2}(CH_{3})_{6})$, $\beta$-SiC film was successfully deposited on a Si substrate at $1100^{\circ}C$ by a chemical vapor deposition method. Selectivity of SiC deposition on a Si substrate partially covered with a masking material was investigated by introducing HCl gas into hexamethyldisilane/$H_{2}$ gas system during the deposition. The schedule of the precursor and HCl gas flows was modified so that the selectivity of SiC deposition between a Si substrate and a mask material should be improved. It was confirmed that the selectivity of SiC deposition was improved by introducing HCl gas. Also, the pulse gas flow technique was effective to enhance the selectivity.

• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1320-1322
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• 1997

The distribution of coercivity in the thickness direction were investigated by using Kerr hysteresis loop tracer for the Co-Cr films deposited by Facing Targets Sputtering apparatus. It $H_{c{\bot}}(S)- H_{c{\bot}}(I)$ correlated strongly with ${\Delta}H_c$, which represents the degree of distribution of coercivity. Furthermore, the Cr content was varied in order to improve the coercivity of intial growth layer $H_{c{\bot}}(I)$ took a maximum value of 750 Oe and the distribution of coercivity became sharper at the Cr content of 25 at.%.

• Bulletin of the Korean Mathematical Society
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• v.44 no.1
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• pp.117-123
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• 2007

In this paper, we first adapt Runge's Theorem to work on certain domains in any complex Banach space. Then, using this result, we extend Birkhoff's Theorem on the hypercyclicity of translations on $H(\mathbb{C})$ and Costakis' and Sambarino's result on the existence of common hypercyclic functions for uncountable families of translations on $H(\mathbb{C})$ to subs paces of $H_b(E)$ (in some cases all of $H_{b}$(E)), E being in a large class of Banach spaces.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.251-252
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• 2008

• Proceedings of the Korean Vacuum Society Conference
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• 1996.02a
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• pp.115-116
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• 1996

• 대한생식의학회:학술대회논문집
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• 1999.11a
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• pp.71.2-72
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• 1999

• Korean journal of food and cookery science
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• v.13 no.2
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• pp.106-112
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• 1997

The effect of low concentrations of allspice (Pimenta dioica L.) in culture broth as an antibacterial agent against Escherichia coli 0157:H7 and Staphylococcus aureus 196E was tested at 35,5 and -20$^{\circ}C$. Tryptic soy broth (TSB) containing 0∼2% (w/v) of allspice was inoculated with 10$\^$5/∼10$\^$6/ cells/$m\ell$ of E. coli and S. aureus and incubated at each temperature. The growth of E. coli was not inhibited at 0.1∼1.0% allspice and growth occured at 2％ allspice but only after a prolonged lag period. Growth of S. aureus was inhibited with increasing concentration of allspice at 35$^{\circ}C$. Growth of S. aureus occured at the presence of 0.1∼0.3% allspice but the viability of S. aureus at 0.5∼2.0% allspice was decreased during storage at 35$^{\circ}C$. During refrigerated storage at 5$^{\circ}C$, inhibition of E. coli and S. aureus was increased with the progress of time and increasing spice concentration. During frozen storage at -20$^{\circ}C$, antibacterial activity of allspice against E. coli was increased with increasing storage time and spice concentration while that activity against S. aureus was effective during early period of storage. There was no major changes in population of S. aureus in TSB with different concentration of spice frozen at -20$^{\circ}C$. Viable counts of E. coli and S. aureus at 0.l％ of allspice was less than that of control during frozen storage.

• Journal of Nutrition and Health
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• v.8 no.1
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• pp.65-69
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• 1975

Human chorionic gonadotropin hormone(H.C.G.) is secreted from the villus tissues of the placenta and excreted in lange amount into the urine. Its isolation is chiefly made from the urine of a pregnant woman. Recently, Matsushima attempted isolation of H.C.G. directly from the placenta itself. In order to prepare H.C.G. from human placenta, general method of extractiag and purifying proteins was applied. Its way was as follow: Crude H.C.G. was extracted from placenta with pH 9.0 and pH 5.0 aqua ammonia, and purified with pH 8.0 ammonia and 50% ethanol at pH 4.8. The purified H.C.G. showed two moving bands on the anode by paper electrophoresis. On the other hand, the H.C.G. from pregnancy urine (Standard. Pharm. Co.) showed same two bands but their moving ratio were different. The purified H.C.G. showed gonadotropin effect when it was injected young fomale rats 40r/cc per day for 5 days and weighted the increased ovary weight.