• 제목/요약/키워드: Mg substitution

검색결과 187건 처리시간 0.033초

Ca 함량 및 Sr 치환량의 변화에 따른 Mg-Ca-Sr-Ti-O계 세라믹스의 마이크로파 특성 (Effect of Ca Contents and Sr Substitutions on Microwave Characteristics of Mg-Ca-Sr-Ti-O System Ceramics)

  • 류현위;유완식;정하창;김배연
    • 한국세라믹학회지
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    • 제43권5호
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    • pp.284-292
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    • 2006
  • $MgTiO_3{\cdot}CaTiO_3{\cdot}SrTiO_3$ system ceramics (MCST) were synthesized to study the effect of Ca addition amount and Sr substitution on temperature coefficient of resonance sequency. Temperature coefficient of resonance frequency was slightly increased by small amount ($i.e.{\sim}5%$) of Sr substitution. In case of 50% to 75% addition amount of $MgTiO_3$, decrease of quality factor was not observed with increasing dielectric constant.

MgO의 첨가량에 따른 $(Ba_{0.5}Sr_{0.5}){TiO_3}$ 후막의 유전 특성 (Dielectirc Properties of $(Ba_{0.5}Sr_{0.5}){TiO_3}$ Thick Films Doped with MgO)

  • 강원석;남송민;고중혁;이영희
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년도 추계학술대회 논문집 전기물성,응용부문
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    • pp.5-6
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    • 2006
  • Using the $(Ba_{0.5}Sr_{0.5}){TiO_3}$(BST) powders prepared by the Sol-Gel method, the EST thick films were fabricated on the ${Al_2}{O_3}$ substrates coated with Pt by the screen printing method. Compared with pure EST thick films, the structural and dielectric properties of the EST thick films doped with 1${\sim}$10 wt % MgO were investigated. It was observed that the Mg substitution into EST causes a shift in the cubic-tetragonal EST phase transition peak to a lower temperature. The microstructure of the EST substituted with Mg was homogeneous and dense. Mg substitution into EST had a significant effect on the grain size reduction. Dielectric constant was decreased with increasing the MgO content and temperature. In the case of EST thick films doped with 1 wt% MgO, the relative permittivity and dielectric loss were 158] and 1.4 % at 1 MHz.

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SrTiO$_{3}$ 고용에 따른 Pb(Mg$_{1/3}$Nb$_{2/3}$)O$_{3}$-PbTiO$_{3}$계 세라믹스의 유전 및 전왜특 (Dielectric and strain properties of Pb(Mg$_{1/3}$Nb$_{2/3}$)O$_{3}$-PbTiO$_{3}$ Ceramic with Respect to the Variation of SrTiO$_{3}$ Substitution)

  • 지승한;이해영;이덕출;이진걸;이연학
    • 대한전기학회논문지
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    • 제45권2호
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    • pp.235-241
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    • 1996
  • In this paper dielectric and electrostrictive strain properties of (1-y-x)Pb(Mg$_{1/3}$Nb$_{2/3}$)O$_{3}$-PbTiO$_{3}$$-yPbTiO_{3}-xSrTiO_{3}[(1-y-x)PMN-yPT-xST]$ ceramics fabricated by using columbite precursor method have been investigated with the substitution of SrTiO$_{3}$(ST). Dielectric constant of the specimens increased with the increase of ST content up to 5[m/o] and decreased with further substitution of ST. And the pyrochlore phase decreased with the increase of ST content up to 5[m/o] in XRD analysis. The elimination of the pyrochlore phase improved dielectric constants. The electrostrictive strains generated by AC electric field have the highest value at 5[m/o] SrTiO$_{3}$ addition and the hysteresis of strain ranged from 12 to 20[%]. The electrostrictive strain at various temperature investigated in the temperature range of $-50[^{\circ}C]~74[^{\circ}C].$ In higher temperature than phase transition region, it showed paraelectric property which shows very small hystersis.

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ZnO-$SnO_2$계 Spinel 채료에 대한 NiO, $TiO_2$의 영향 (Influence of NiO, $TiO_2$ on ZnO-$SnO_2$ System Spinel Pigment)

  • 이응상;황성윤
    • 한국세라믹학회지
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    • 제14권3호
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    • pp.187-192
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    • 1977
  • For the purpose researching to the influence of tetrahedral and octahedral preference of cations of $Ni^{2+}$, $Ti^{4+}$ upon the formation and the color development of the $ZnO-SnO_2$ spinel containing $Ni^{2+}$ and $Ti^{4+}$ ions, the gradual substitution of $Ni^{2+}$ ions for $Zn^{2+}$ ions and of $Ti^{4+}$ ions for $Sn^{4+}$ ions of the spinel in NiO-ZnO-$SnO_2$-$TiO_2$ system was carried out. On samples prepared by calcining the oxide and basic cabonate mixtures at $1300^{\circ}C$ for 2 hours, the X-ray analysis, measurement of reflectance and the test of their stabilaity as a glaze pigment were also carried out. The results are summarized as follows 1) Single spinel was formed completely to x=1 in the $xNiO\cdot(2-x)ZnO\cdot{SnO}_2$system, and gave brilliant lightgreen hue. Moreover, $NiO\cdot{ZnO}\cdot{SnO}_2$ formed easily spinel than $NiO\cdot{MgO}\cdot{SnO}_2$ because Zn^{2+}$ ions had more strong tetrahedral preference than $Mg^{2+}$ ions. 2) As the gradual substitution of $Ti^{4+}$ ions for $Sn^{4+}$ ions in $NiO\cdot{MgO}\cdot{SnO}_2$ system, the spinels formed well and was nearly not changed in the hue. 3) The results of glaze test. (1) As the gradual substitution of $Ni^{2+}$ ions for $Zn^{2+}$ ions, the color changed from dull white to graish broun gradually in calcium-zinc glaze and calcium glaze, and from white to beige in tile glaze. (2) As the gradual substitution of $Ti^{4+}$ ions for $Sn^{4+}$ ions in $NiO-ZnO-SnO_2-TiO_2$ system, the color was become dull generally and was not change in tile glaze.

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$MnO_2$치환된 PMN계 세라믹스의 유전특성 (A study on Dielectric Properties usig PMN Ceramics with $MnO_2$ substitution)

  • 지승한;유도현;이은학;김영일;박광현;이덕출
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1997년도 하계학술대회 논문집 C
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    • pp.1537-1539
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    • 1997
  • In this study, the dielectric properties of $Pb(Mg_{1/3}Nb_{2/3})O_3-PbTiO_3$ Ceramics have been investigated as a addition of the amount of $MnO_2(0{\leq}x{\leq}0.9wt%)$. The Temperature-dependant dielectric characteristics of 0.9PMN-0.1PT relaxor ferroelectric system were improved by enhencing the extent of the diffuse phase transition(DPT). The maximum dielectric permittivity decreased by substitution $MnO_2$ and the dielectric loss decreased with increasing $MnO_2$ substitution amount. It is expected decreasing in inner heat energy for temperature with increasing $MnO_2$ substitution.

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장군 연-아연 광상의 모암변질대내 탄산염 광물의 산상 및 화학조성 (Occurrence and Chemical Composition of Carbonate Mineral from Wallrock Alteration Zone of Janggun Pb-Zn Deposit)

  • 유봉철
    • 광물과 암석
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    • 제36권3호
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    • pp.167-183
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    • 2023
  • 장군 연-아연 광상은 망간 광체, 연-아연 광체 및 철 광체로 구성된다. 이 망간 광체는 생성환경 및 광물 조합을 토대로 탄산망간 광체와 산화망간 광체로 구성된다. 이 광상 지질은 선캠브리아기의 원남층, 율리층군, 캠브리안기내지 오도비스기의 장산규암층, 두음리층, 장군석회암층, 석탄기내지 이엽기의 동수곡층, 재산층, 쥐라기의 동화지층 및 이들을 관입한 중생대의 춘양화강암류로 구성된다. 이 탄산망간 광체는 고생대 캠브리안기내지 오도비스기의 장군석회암층에 연-아연 열수용액과 반응에 의해 형성된 열수교대형 광체이다. 이 열수교대형 광체의 연-아연 광화작용과 관련된 모암변질작용은 주로 능망간석화작용과 일부 돌로마이트화작용, 황철석화작용, 견운모화작용 및 녹니석화작용 등이 관찰된다. 정출순서에 따른 모암변질작용 시 형성된 탄산염 광물은 Ca-돌로마이트(Co형, 모암) → 철백운석과 Ferroan 철백운석(C1형, 초기) → 철백운석(C2형) → 시데로플레사이트(C3형) → 시데로플레사이트 및 피스토메사이트(C4형, 후기)가 형성되어 Fe와 Mn 원소들이 부화되는 방향으로 진행되었다. 따라서 정출순서에 따른 모암변질작용 시 형성된 모암인 돌로마이트질 대리암(Mg, Ca 기원)과 연-아연 열수용액(Fe, Mn 기원)과 원소들의 치환관계를 살펴보면 다음과 같다. 1)초기 백운석 및 Ferroan 철백운석(C1형)은 Fe ↔ Mn 및 Mn ↔ Mg, Ca, Fe 원소들간 치환에 의해 형성, 2)철백운석(C2형)은 Fe ↔ Mn, Mn ↔ Mg, Ca 및 Mg ↔ Ca 원소들간 치환에 의해 형성, 3)시데로플레사이트(C3형)은 Fe ↔ Mn, Fe ↔ Ca 및 Mn ↔ Mg, Ca 원소들간 치환에 의해 형성과 4)후기 시데로플레사이트와 피스토메사이트(C4형)은 Fe ↔ Mg, Fe ↔ Mn 및 Mn ↔ Mg, Ca 원소들간 치환에 의해 형성되었다.

Combined Effects of Sodium Substitution and Addition of Cellulose or Chitosan on Quality Properties of Pork Sausages

  • Jin, Sang Keun;Hur, Sun Jin;Yim, Dong Gyun
    • 한국축산식품학회지
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    • 제39권4호
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    • pp.555-564
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    • 2019
  • The aim of this study was to assess the impacts of cellulose/chitosan addition in combination with sodium substitution, including KCl and $MgCl_2$, on the quality and sensory properties of sausages. Sausages (control, 100% NaCl; T1, 60% NaCl, and 40% KCl; T2, 50% NaCl, 40% KCl, and 10% $MgCl_2$) were formulated with cellulose/chitosan at concentrations of 3% and compared to control. T1 and T2 decreased the pH values (p<0.05), while the use of cellulose increased these values. Biopolymer addition reduced lipid oxidation (p<0.05). In sausages containing cellulose, volatile basic nitrogen (VBN) in T1 was lower than that in T2 (p<0.05). The use of cellulose increased L*-, a*-, and W color values in T1 (p<0.05). Furthermore, cellulose addition was associated with lower hardness (p<0.05). Cellulose addition contributed to better overall acceptability (p<0.05). Consequently, a combined mixture containing T1 and cellulose appears to be the best combination, indicating a possible synergistic effect.