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삼산화안티몬(Sb<sub>2</sub>O<sub>3</sub>) 제조 사업장 주변의 토양과 지하수, 하천수를 대상으로 거리와 방향에 따른 안티몬(Sb) 농도변화를 고찰하여, 사업장에서 배출되는 안티몬이 주변 환경에 미치는 영향에 대해 검토 하였다. 토양시료 19개 지점 중 13개 지점에서 평균 농도 29.621㎎/㎏으로 Sb이 검출되었으며, NW 30m, S 50m, S 130m 지점의 Sb 농도는 각각 50.667, 93.333, 75.0㎎/㎏으로 비교적 높게 나타났다. 이는 ISCLT 모델링에 의한 최고 등농도곡선 0.6㎍/㎥ 범위인 300m 이내 지점이었으며, 주풍의 풍하방향인 남동과 북서의 경우, 사업장에서 멀어질수록 Sb 농도는 감소하였으며 50m 이내에서는 50㎎/㎏ 내외의 고농도를 보이다가 300m 이후 급격히 감소하여, 500m 이상의 지역에서는 검출되지 않는 것으로 나타나 사업장 주변 500m 이내 지역이 배출원의 영향권이라 판단되었다. 사업장과 인접한 하천수와 마을 지하수 시료 중 일부에서 Sb이 검출되어 대체급수 대책과 토양, 하천수, 지하수 등 환경 매체별 기준을 설정하여 관리할 필요성이 있는 것으로 나타났다. This study is aimed at investigation of the influence for Antimony(Sb) exhausted from Sb manufacturing companies to the adjacent contamination of soil. On analysis of the 19 soil samples, Sb concentration of the detected 13 samples were average 29.621㎎/㎏ and those for NW 30m, S 50m, and S 130m point which is within 300m of 60㎍/㎥ maxium equavlent concentration curve by ISCLT model were analyzed 50.667㎎/㎏, 93.333㎎/㎏, and 75.0㎎/㎏ on the 13 samples respectively. At the NE and NW that downwind direction of the main wind, Sb concentration has decreased as longer as the company, about higher 50㎎/㎏ within 50m, shrank suddenly after 300m, and didn`t detected over 500m. So, the effect sphere of Sb is considered within 500m around the exhausting source.
The sintering behavior and microwave properties of Ba₃Co<SUB>2-2x</SUB>Mn<SUB>2x</SUB>Fe₂₄O₄₁ ceramics were investigated. All samples were prepared by the conventional mixed oxide method and sintered at 1150℃∼1400℃. From the X-ray diffraction patterns of sintered Ba₃Co<SUB>2-2x</SUB>Mn<SUB>2x</SUB>Fe₂₄O₄₁ ceramics, the Z-type phase was existed as main phase at sintering temperature of 1350℃. The permittivity and permeability of Ba₃Co<SUB>2-2x</SUB>Mn<SUB>2x</SUB>Fe₂₄O₄₁ ceramics were increased with Mn additions and decreased rapidly over frequency of 600 ㎒. The loss tangent of permittivity and of permeability did not changed hardly with composition ratio and increased over frequency of 600 ㎒. The magnetic resonance frequency of Ba₃Co<SUB>2-2x</SUB>Mn<SUB>2x</SUB>Fe₂₄O₄₁ ceramics was about 600 ㎒. The permittivity, loss tangent of permittivity, permeability and loss tangent of permeability of Ba₃Co<SUB>1.4</SUB>Mn<SUB>0.6</SUB>Fe₂₄O₄₁ ceramics sintered at 1250℃ were 27.276, 0.171, 20.448 and 0.068 at 310 ㎒, respectively.
In this study, the sintering properties and structural properties of the Mg?Ta₄O₁? cation-deficient perovskite ceramics with Li₂CO₃ additions are investigated. The cation-deficient perovskite ceramics are prepared through the solid-state route. According to the XRD pattern, Mg₄Ta₂O?, MgTa₂O? and Mg?Ta₄O₁? phase existed in sintered pure Mg?Ta₄O₁? ceramics. With Li₂CO₃ additions, the peak intensities of Mg₄Ta₂O? and MgTa₂O? phase were reduced. Also, diffraction intensity of the Mg? Ta₄O₁? phase was increased with increments of Li₂CO₃ additions. The bulk densities were increased with increasing of Li₂CO₃ amount and approach the theoretical density of the Mg?Ta₄O₁? ceramics, more and more. Microstructure of the Mg?Ta₄O₁? ceramics were densified more and more by additions of Li₂CO₃. The bulk density of Mg?Ta₄O₁?+5wt% Li₂CO₃ ceramics sintered at 1500℃ for 10 hours was 5.88 g/㎤.
In this study, low temperature sintering property of the 0.6TiTe₃O?-0.4MgTiO₃ ceramics with sintering adds were investigated for LTCC application which enable to cofiring with Ag electrode. TiTe₃O? mixed with MgTiO₃ to improve the temperature property. In the X-ray diffraction patterns, the columbite structure of TiTe₃O?, phase and ilmenite structure of MgTiO₃ phase were coexisted in all specimens. In the case of H₃BO₃ addition, the bulk density and dielectric constant were decreased but quality factor was increased with amount of H₃BO₃ additions. The TCRF of the 0.6TiTe₃O?-0.4MgTiO₃+xwt%H₃BO₃ ceramics were moved to positive direction. In another case, SnO addition, the bulk density and dielectric constant were increased but quality factor was decreased with amount of SnO additions. The TCRF of the 0.6TiTe₃O?-0.4MgTiO₃+ywt%SnO ceramics were shifted to negative direction. The dielectric constant, quality factor and TCRF of the 0.6TiTe₃O?-0.4MgTiO₃ ceramics with 2wt%H₃BO₃ and 2.5wt%SnO sintered at 830℃ for 1h. were 28.5, 39,570㎓, +9.34ppm/℃ and 29.86, 35,800㎓, -0.58ppm/℃, respectively.
In this study, structural and micowave dielectric properties of the Mg?B₄O₁? (B=Ta, Nb) cation-deficient perovskite ceeramics. The specimens are prepared through the solid-state route. According to the XRD pattern, Mg₄Ta₂O? and MgTa₂O? phase exist in calcined and sintered Mg?Ta₄O₁? powder. Also Mg?Ta₄O₁? phase added with increasing sintering temperature. In the case of calcined and sintered Mg?Nb₄O₁? powder, single phase of Mg?Nb₄O₁? were appeared. The bulk density and quality factor of the Mg?B₄O₁? (B=Ta, No) ceramics were increased with sinterning temperature in 1400℃~1450℃, but these were decreased in another sintering temperature. Dielectric constant of the Mg?Ta₄O₁? ceramics was increased continuously with increasing of sintering temperature. And the dielectric constant of the Mg?Nb₄O₁? ceramics was increased in 1400℃~1450℃ but decerased in 1475℃. In the case of the Mg?Ta₄O₁? and Mg?Nb₄O₁? ceramics sintered at 1450℃ for 5h, the dielectric constant, quality factor, and temperature coefficient of the resonant frequency (TCRF) were 8.2, 259,473 ㎓, -10.91 ppm/℃ and 14, 37,350 ㎓, -52.3 ppm/℃. respectively.