• 한국초전도학회:학술대회논문집
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• 한국초전도학회 2000년도 High Temperature Superconductivity Vol.X
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• pp.70-75
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• 2000

We report results of a comparative study of the normal-state and superconducting properties in the GdBa$_2$(Cu$_{2.9}$Al$_{0.1}$)O$_z$ system with substitutions by Pr for the Gd and Ba sites. It is observed that, fur both Pr-doped systems, the superconducting transition temperature(T$_c$) decreases almost linearly with the Pr-content, but Pr at Ba sites results in a faster T$_c$ drop than that of Pr at Gd sites. The thermoelectric power measurements indicate that there is a strong correlation between the T$_c$ and the room temperature value of thermoelectric power. The experimental results are discussed in connection with existing models.

• 한국세라믹학회지
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• 제26권6호
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• pp.843-849
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• 1989

Effect of Bi2O3/Li2CO3 on low temperature sinteirng and dielectric property of BaTiO3 ceramics has been investigated. For the specimen sintered at 110$0^{\circ}C$, it was densified to 96% of BaTiO3 theoretical density by the addition of 1.0-1.25w/o Bi2O3/Li2CO3. Maximum dielectric constant increased and Curie temperature lowered with the increase of Bi2O3/Li2CO3 content, which probably can be explained by thne substitution of Bi3+, Li1+ on BaTiO3 lattice. The volatilization of Li1+, resulting from the increase of soaking time at 110$0^{\circ}C$ leads to the increase of Curie temperature and tetragonality of the specimen.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2004년도 SMICS 2004 International Symposium on Maritime and Communication Sciences
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• pp.6-8
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• 2004

The NdBaCuO superconductor samples were zone-melted in low oxygen partial pressure (1 % $O_2$＋99%Ar). The zone-melting temperature was decreased about 12$0^{\circ}C$ from 1, 06$0^{\circ}C$, the zone-melting temperature in air. Thus the loss of liquid phase (BaCu $O_2$and CuO) was reduced during the zone-melting process. The content of non-superconducting phase Nd422 in zone-melted NdBaCuO samples was clearly decreased and, therefore, the substitution of Nd for Ba was occurred. The superconductivity of zone-melted N $d_{1＋x}$B $a_{2－x}$C $u_3$ $O_{y}$prepared under low oxygen partial pressure was distinctively improved.d.d.d.

• Journal of Magnetics
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• 제21권4호
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• pp.496-502
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• 2016

Doped and undoped barium hexaferrite powders ($BaFe_{12}O_{19}$, $Ba_{0.7}Ti_{0.3}Fe_{12}O_{19}$ and $Ba_{0.7}La_{0.3}Fe_{12}O_{19}$) were produced by the sol-gel method. The effects of substituting elements were studied in terms of the magnetic properties of barium hexaferrite powders. The magnetic properties were remarkably changed by the substitution of $La^{3+}$ and $Ti^{4+}$ ions for the $Ba^{2+}$ ion and were accompanied by oxygen deficiency in the $BaFe_{12}O_{19}$. Coercivities ($H_C$) from 4200 to 5100 Oe, remanences ($M_R$) from 22 to 49 emu/g and saturation magnetizations ($M_S$) from 41 to 73 emu/g were obtained for different samples. The obtained results were discussed in detail.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2011년도 임시총회 및 하계학술연구발표회
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• pp.17-18
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• 2011

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2003년도 추계총회 및 연구발표회 초록집
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• pp.98.1-98
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• 2003

• 한국세라믹학회지
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• 제25권3호
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• pp.268-276
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• 1988

KCI을 사용한 용융염합성법에 의해 침상형$(Pb_{1-x}Ba_x)_{1-y}La_{2y/3}Nb_2O_6$ (PBLN)분말을 합성하고 합성분말의 형상에 미치는 Ba 및 La 치환의 영향을 조사하였다. 또 이 침상형 분말을 사용하여 doctor-blade법 및 hot-press 법에 의해 입자배향 세라믹스를 제작하고 유전적, 압전적, 광학적 성질을 조사하였다. 얻어진 PBLN 분말의 형상 및 입자배향 PBLN 세라믹스의 전기적 특성은 분말합성시의 열처리조건과 Ba 및 La 치환량에 따라 현저히 달랐다. 특히 PBLN 세라믹스의 유전율 및 전기기계결합계수는 입자배향 세라믹스 제작시의 가압방향에 따라 뚜렷한 이방성을 나타내었다.

• 한국초전도ㆍ저온공학회논문지
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• 제4권1호
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• pp.21-25
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• 2002

The effect of Ca-doping on the superconducting properties of Nd-Ba-Cu-O bulk superconductors, fabricated by the oxygen-controlled melt growth process, has been systematically investigated. Various c-axis textured bulk samples were grown using precursors with the nominal compositions of $Nd_{1.8-x}Ca_{x]Ba_{2.4}Cu_{3.4}O_{y}$ (x= 0.00, 0.02, 0.05, 0.10, 0.15) in a reduced oxygen atmosphere of 1%O$_2$ in Ar. Magnetization measurements revealed that the critical temperatures(Tc) were almost linearly depressed from 95K to 86K with increasing the Ca dopant from x : 0.0 to 0.15, respectively, and thus critical current densities(Jc) at 77K and for H//c-axis of specimens were gradually degraded with increasing x. Compositional analyses revealed that although the amounts of the Ca dopant both in $NdBa_2Cu_2O_y(Nd123) and Nd_4Ba_2Cu_2O_{10}(Nd422)$,/TEX> were increased with increasing x, only less than half of the initial Ca compositions were detected in melt-grown Ca-doped Nd-Ba-Cu-O bulk crystals. The supression of Tc is attributed to an increased Nd substitution for the Ba site in the Nd123 superconducting matrix with increasing the amount of the Ca dopant.

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2003년도 춘계총회 및 연구발표회 초록집
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• pp.186.2-186
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• 2003

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 가을 학술발표회 논문집
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• pp.775-780
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• 2002

Sandwich panel made by foamed styrene and ployuretane has been used generally in the construction area because of the high thermal conductivity and light weight but they occur harmful gases to both bodies and environments in the high temperature over $50^{\circ}C$. So, the purpose of this study is to investigate the physical properties of light-weight panel using the non-structural lightweight aggregate as a part of the substitution of foamed styrene and ployuretane. This paper dealt with the effect of the addition of polymer dispersion such as SBR, St/BA-1 and St/BA-2 having polymer-cement ratio as 5, 10, 15% and the filling ratio of continuous void as 50, 60% on the strength of polymer-modified sandwich panel core. From the results, we could know that the compressive and flexural strength of the sandwich panel core using non-structural lightweight aggregate and polymer dispersion such as SBR, St/BA-1 and St/BA-2 tended to be increased with an increase in the polymer-cement ratio and the filling ratio of continuous void.