• 대한의용생체공학회:의공학회지
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• 제12권1호
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• pp.57-62
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• 1991

ABA type block copolymers composed of poly($\gamma-benzyl$ L-glutamate) (PBLG) as the A component and poly (ethylene glycol) as the B component were obtained by polymerization of $\gamma-benzyl$ L-gletamate N -carboxyanhydride, initiated by amino groups at both ends of poly(ethylene glycol) . From circular dichroism measurements in ethylene dichloride solution as well as from infrared spectTa measurements in solid state, it was found that the polypep- tide block exists in the a-helical conformation, as in PBLG homopolymer. $Poly-N^5$ (3-hydroxypropyl glutamine) (PHPG)/poly(ethylene glycol)block copolymer hydrogel was obtained by the treatment of PBLG/PBG block copolymer with the mixture of 3-ammine-1-propanol and diamlnooctane. The water content of PHPG/PEG block copolymer hydrogel was about 80wt% when the concentration of crosslinking agent was below 5 mole % per polymer.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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• pp.1526-1528
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• 2007

In this report, Manganese doped magnesium germanate ($Mg_4GeO_2:Mn$) phosphor has been synthesized by the solid state method. Also, this phosphor was prepared by simple process under an air atmosphere for oxidation of Mn. The prepared phosphor shows a main luminescent peak at 661nm. Therefore, this phosphor is possible to be applicable to white LED lamp by GaN or InGaN chips.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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• pp.1529-1530
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• 2007

The manganese co-doped $Ca_8Mg_1(SiO_4)_4Cl_2:Eu^{2+}$,$Mn^{2+}$ phosphor was synthesized by solid-state reaction and its photoluminescence characteristics were investigated. The synthesized phosphor show two emission spetrums: green band of 512nm and yellow band of 550nm. White light-emitting diodes (LEDs) were fabricated through combination of a 405nm-emitting InGaN chip and a synthesis phosphor in a single package. Under 20mA current, its CIE chromaticity coordinates are x=0.40 and y=0.45 and a color temperature of 4053K.

• Applied Science and Convergence Technology
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• 제24권3호
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• pp.47-52
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• 2015

The correlation between admittance and dielectric spectroscopy of dielectric relaxation in lead scandium noibate, have been investigated. Lead scandium niobate, with composition $PbSc_{0.5}Nb_{0.5}O_3$, was prepared by conventional solid state synthesis. Conductance Y'(G), susceptance Y"(B) and capacitance C of lead scandium niobate as a function of frequency and temperature were measured. From the temperature-dependence of RLC circuit, insight into physical significance of the dielectric properties of lead scandium niobate is obtained. The relative strong frequency dependent of dielectric properties in lead scandium niobate is observed, and the phase transition occurred at a broad temperature region. Also, the value of critical exponent ${\gamma}$=1.6 showed on heating process. The long relaxation times part enlarged diffuse by conductivity effects with increasing temperature, and the ordering between $Sc^{3+}$ and $Nb^{5+}$ in PSN influences complex admittance and dielectric properties. Confirmed the typical characteristic of lead-type relaxor in the Raman spectra of lead scandium niobate and major ranges are between 400 and $900cm^{-1}$.

• 한국결정성장학회:학술대회논문집
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• 한국결정성장학회 1998년도 PROCEEDINGS OF THE 14TH KACG TECHNICAL MEETING AND THE 5TH KOREA-JAPAN EMGS (ELECTRONIC MATERIALS GROWTH SYMPOSIUM)
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• pp.115-119
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• 1998

Possibilities of substitution was investigated in the Langadite({{{{ {La }_{3 } {Ga }_{ 5}{SiO }_{14 }}}}}) system.{{{{{TiO}_{2 }}}}} was substitutes for{{{{{SiO}_{2 }}}}} followed by the substitution of{{{{{Nd}_{2 }{O}_{3}}}}}fo{{{{{La}_{2 }{O}_{3}}}}}. An effort to replace GeO2, which is reported to have been substitution for{{{{{SiO}_{2 }}}}} in the Langasit e system, for{{{{{TiO}_{2 }}}}} i n{{{{{ Nd}_{ 3} {Ga }_{5 } {TiO }_{14 } }}}} was also undertaken. In another experiment,{{{{{ Y}_{ 2}{ O}_{3 } }}}} was substituted for{{{{{ La}_{2 } {O }_{ 3} }}}}. All of substitution possibilities were investigated through solid state reactions and analyzed with XRD. Further analysis was carried out with an SEM. Lastly, the dielectric constants of the sintered body were measured.

• Bulletin of the Korean Chemical Society
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• 제32권9호
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• pp.3333-3337
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• 2011

$ZnMn_2O_4$ has been prepared by a mechanochemical process using a mixture of $Mn_2O_3$ and ZnO as starting materials, and investigated as a possible anode material for lithium-ion batteries. The phase evolution and morphologies of the ball-milled and annealed powders are characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) with energy dispersive microanalysis (EDX), respectively. The solid-state reaction for the formation of $ZnMn_2O_4$, under the given experimental conditions, is achieved in a short time (30 min), and the prepared samples exhibit excellent electrochemical performances including an enhanced initial coulombic efficiency, high reversible capacity, and stable capacity retention with cycling.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.591-593
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• 2008

In this report, cerium doped lutetium aluminate ($Lu_3Al_5O_{12}$:Ce) phosphor has been synthesized by the solid state method under reduction atmosphere with mixture gas. The prepared phosphor shows a main luminescent peak at 555nm. Consequently, this phosphor is possible to be applicable to white LED lamp by InGaN chips.

• The Korean Journal of Ceramics
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• 제5권3호
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• pp.217-223
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• 1999

Proten-conductive $SrZr_{0.95} Y_{0.05} O_{2.975}$ powder was prepared by citrate gel method its characteristics and sinterability were investigated. Amorphous gel could be obtained from a citric acid solution that $SrCO_3$ and metal nitrates were dissolved. The initial decomposition of the gel proceeded up to $250^{\circ}C$, followed by combustion of its decomposition products in the temperature range from $250^{\circ}C$ to $500^{\circ}C$. A well-crystallized perovskite phase with a stoichiometric composition after calcination at $1000^{\circ}C$. Sintering green compacts of this powder for 6 h showed a considerable densification to start at $1200^{\circ}C$ and resulted in 86.8% and 96.5% relative densities at $1400^{\circ}C$ and $1600^{\circ}C$, respectively. Whereas, the powder compacts prepared by solid state reaction had much lower relative densities, 73% at $1400^{\circ}C$ and 92% at $1600^{\circ}C$.

• Bulletin of the Korean Chemical Society
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• 제35권7호
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• pp.2077-2080
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• 2014

Cobalt-immobilized SBA-15 6a-c was synthesized from alkyne-attached SBA 5a-c by the reaction with $Co_2(CO)_8$ in toluene. Alkyne group was introduced into amino SBA-15 (4) by imine-linkage or substitution with propargyl bromide to afford iminoalkyne 5a and aminoalkyne 5b, respectively. Meanwhile, alkyne 5c was prepared in one-step by reacting triethoxysilyl hexyne with SBA-15. Dicobalt-complexes 6a-c were characterized by means of FT-IR, solid-state NMR and elemental analysis.

• Applied Science and Convergence Technology
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• 제23권6호
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• pp.371-375
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• 2014

Diffusion coefficient of Fe in polycrystalline host ZnSe as a mid-IR gain medium has been measured in the annealing temperature ranges of 850 to $950^{\circ}C$. The synthesis of the samples was carried out in quartz ampoule in which the Fe thin film deposited by physical vapor evaporation method on the ZnSe. One can realize that the diffusion coefficient strongly depends on the surface active surfactants through the cleaning process and the substrate temperature during the thin film deposition leading to $2.04{\times}10^{-9}cm^2/s$ for $Fe^{2+}:ZnSe$. The Annealing temperature dependence of the Fe ions diffusion in ZnSe was used to evaluate the activation energy, $E_a$=1.39 eV for diffusion and the pre-exponential factor $D_0$ of $13.5cm^2/s$.