Abstract: A sintered body for thermistor element of the invention is a sintered body for thermistor element containing Sr, Y, Mn, Al, Fe, and O, wherein not only respective liquid crystal phases of a perovskite type oxide and a garnet type oxide are contained, but also a liquid crystal phase of at least one of an Sr—Al based oxide and an Sr—Fe based oxide. FeYO3 and/or AlYO3 is selected as the foregoing perovskite type oxide, and at least one member selected from Y3Al5O12, Al2Fe3Y3O12, and Al3Fe2Y3O12 is selected as the foregoing garnet type oxide, respectively by the powder X-ray diffraction analysis.

Abstract: Disclosed herein is a microwave dielectric ceramic composition which comprises as the main ingredient, a composition represented by xMgTiO.sub.3 .multidot.(1-x)CaTiO.sub.3 (0.93.ltoreq.x .ltoreq.0.95), to which 3-9 wt % of ZnO, 2-4 wt % of Ta.sub.2 O.sub.5, 1-6 wt % of Nb.sub.2 O.sub.5, 0.1-6 wt % of MnO.sub.2, 3-12 wt % of Al.sub.2 O.sub.3 or 3-12 wt % of Co.sub.2 O.sub.3 to xMgTiO.sub.3 .multidot.(1-x)CaTiO.sub.3. And the microwave dielectric ceramic compositions have a Qu value in the range of 3000 to 4600 (at 6 GHz), a temperature coefficient of the resonance frequency (.tau.f) in the range of -10 to +10 ppm/.degree.C. and relative dielectric constant (.epsilon..sub.r) in the range of 18 to 22. The dielectric ceramic compositions are capable of reducing .tau.f approximately to zero or optionally and stably controlling .tau.f to a desired value both to positive and negative sides around zero as the center while maintaining .epsilon..sub.

Abstract: A dielectric ceramic composition which comprises a composition represented by xBaO.yNd.sub.2 O.sub.3.zTiO.sub.2 (where 8.5.ltoreq.x.ltoreq.20, 5.ltoreq.y.ltoreq.23, 62.ltoreq.z.ltoreq.85, and x+y+z=100), Y.sub.2 O.sub.3 in an amount not more than 15 wt % of the amount of said composition, and Al.sub.2 O.sub.3 in an amount not more than 2 wt % of the total amount of the principal components BaO, Nd.sub.2 O.sub.3, TiO.sub.2, and Y.sub.2 O.sub.3. And a relative permittivity .epsilon.r of the dielectric ceramic is not less than 59, its dielectric loss (tan .delta.) is 3.times.10.sup.-4 .about.8.times.10.sup.-4 (2.7 GHz), and its temperature coefficient of resonant frequency .tau.f may be -30.about.+10 ppm/.degree.C. This microwave ceramic dielectric will be used for dielectric resonators in the microwave frequency region, microwave IC substrates, and impedance matching of microwave circuits.

Abstract: An aluminum oxide-based sintered object having excellent abrasion resistance includes .alpha.-aluminum oxide, a silicon compound and a tungsten compound, wherein the silicon compound and the tungsten compound are present in amounts based on starting amounts of SiC and W metal of from 5 to 40 mole % and from 0.5 to 25 mole %, respectively, based on the sintered object overall, with a W/SiC molar ratio of 4 or less, and in which particles of at least one of tungsten carbide and tungsten silicide having an average particle diameter of 0.5 .mu.m or less are dispersed as a crystalline phase.

Abstract: Disclosed is a BaO-xTiO.sub.2 dielectric ceramic composition (x=3.5 to 4.5) containing BaTi.sub.4 O.sub.9 and Ba.sub.2 Ti.sub.9 O.sub.20, wherein the content ratio of Ba.sub.2 Ti.sub.9 O.sub.20 {Ba.sub.2 Ti.sub.9 O.sub.20 /(BaTi.sub.4 O.sub.9 +Ba.sub.2 Ti.sub.9 O.sub.20)}obtained by a X-ray diffraction maximum peak height integration method described below is less than 0.19,content ratio of Ba.sub.2 Ti.sub.9 O.sub.20 ={a peak height ascribed to the (421) face of Ba.sub.2 Ti.sub.9 O.sub.20 +a peak height ascribed to the (222) face thereof}/[{a peak height ascribed to the (200, 140) face of BaTi.sub.4 O.sub.9 +a peak height ascribed to the (121) face thereof+a peak height ascribed to the (230, 150) face thereof}+{a peak height ascribed to the (421) face of Ba.sub.2 Ti.sub.9 O.sub.20 +a peak height ascribed to the (222) face thereof}].In the above dielectric ceramic composition, it is possible to prevent the occurrence of hexagonal pattern cracks and hence to improve the yield.

Abstract: A method of producing a sintered body by molding a mixture of a ceramic base powder, a sintering assistant powder and an organic binder and sintering the molded body in a non-oxidizing atmosphere is disclosed in which the ceramic base powder has such a particle size distribution that the amount of powder particles not greater than 1.0 .mu.m in size is not more than 15% by weight and the average particle diameter is not greater than 5 .mu.m. According to the method, therefore, sufficient passage of gas is secured in a degreasing step, resulting in an enhanced degreasing efficiency and exellent sintering properties. Where the sintering assistant powder has such a particle size distribution that the amount of powder particles not greater than 10 .mu.m in size is not more than 5% by weight, the amount of coarse powder is extremely small and, therefore, large voids are not formed.

Abstract: Disclosed herein is a ceramic composition which gives a microwave dielectric having a permittivity and unloaded Q in a practical range and a small temperature coefficient (.tau.f) in the neighborhood of zero of resonance frequency owing to the controlled amount of ZnO and Ta.sub.2 O.sub.5 added. The .tau.f value may be positive or negative in the neighborhood of zero according to need. The ceramic composition comprises a principal component represented by (BaO-3.7TiO.sub.2).xZnO, where x is in the range of 15.ltoreq.x.ltoreq.17 wt % and a secondary component containing 2-6 wt % Ta.sub.2 O.sub.5 and not more than 1 wt % MnO.sub.2 based on the amount of the principal component. The ceramic composition may also contain BaO-3.8TiO.sub.2, 12-16 wt % ZnO, and 2-6 wt % Ta.sub.2 O.sub.5, or contain BaO-3.6TiO.sub.2, 17-19 wt % ZnO, and 2-6 wt % Ta.sub.2 O.sub.5.

Abstract: Disclosed herein is a microwave dielectric ceramic composition which comprises a compound represented by the formula BaO.multidot.xTiO.sub.2 (where 3.7.ltoreq.x.ltoreq.4.5) which is incorporated with 1.0-10 wt. % Ba.sub.3 Ti.sub.12 Zn.sub.7 O.sub.34 and 2-8 wt. % Ta.sub.2 O.sub.5. It has well-balanced performance owing to a Q value not less than 8000 (at 4.5 GHz), a relative permittivity .epsilon. not less than 31, and a practical temperature coefficient in the range of -15 to +10 ppm/.degree.C. It may be further incorporated with 0.1-0.4 wt. % MnO.sub.2 for improved sinterability in addition to the above-mentioned performance.

Abstract: A concentration measuring method and an apparatus measures the concentration of an objective solvent in a mixed solution by flowing a mixed solution through a tube, transmitting light through the mixed solution as it flows through the tubing and measuring the quantity of light transmitted through the fluid. The concentration of the objective solvent in the mixed solution is measured on the basis of either the quantity of light transmitted, the diameter of a light beam received, or a point of convergence of the light transmitted through the mixed solution. These factors being dependent on the concentration of the objective solvent in the mixed solution.

Abstract: A ceramics spike pin is provided with a pin body having a horizontal cross section of a substantially circular shape, which pin body is provided with a rounded free end portion having a predetermined radius of curvature and a connecting base portion having a predetermined radius of curvature, and a horizontally expanded base connected to the connecting base portion, wherein a diameter (d) of the connecting base portion in horizontal cross section, the radius of curvature(r) of the connecting base portion, and a maximum diagonal length (D) of the horizontally expanded base satisfy the relationship of 0<r<d<D and r.sup.2 .times.d/D.gtoreq.1.36. Accordingly, the stress concentration can be greatly relieved, and the impact resistance can be improved to thereby the durability.