Poling condition and heat resisting properties were discussed for leadzirconate titanate (PZT) cearmics.High temperature poling which was carridout by applying constant current from above Curie temperature to below Curietemperature in air gave superior heat resisting properties to normal polingmethod in silicon oil bath. Moreover, distinct domain structures were observedin high temperature poling sample. From these results, it was concludedthat high temperature poling resulted in stable domain structures, and consequently brought about superior heat resisting properties.

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In the pyrometallurgical treatment of tin, it has been known that the selectionof optimum slag composition has a significant to promote a smelting efficiency.
In order to decide the slag composition, it is essential to investigatethe thermodynamic characteristics of the molten slag, such as the activity of SnO in the slag.
In the present study, the activity of SnO in the molten SnO-SiO₂ binary systemwhich is the basic system of tin smelting slag was studied by EMF methodusing a zirconia solid electrolyte, and then the influence of addition of CaO, FeO and Al₂O₃ components on the activity of SnO was also examinated.
The results obtained are summarized as follows:
1) The activity of SnO in the molten SnO-SiO₂ system shifts from positive tonegative compared with Raoult's low as the molar ratio of SiO₂ is raised.
2) The activity of SnO raises by additing CaO to SnO-SiO₂ system, and this effecttend to be remarkable with increase of SiO₂ content in the slag.
3) The influence of FeO addition on the activity of SnO in SnO-SiO₂ system isnot observed remarkably, but the activity of SnO raises slightly only in thecase in which SiO₂ content in slag is high.
4) The influence of Al₂O₃ addition on the activity of SnO in the SnO-SiO₂ systemis not so observed.

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In this paper, in order to create a new concept of “light” in future materialscivilization, the light technologies in various pre-modern materials civilizations accepting “night and day” as they are, were taken into notice and discussedfrom a point of materials civiliqation. As the result, “electric candle” was conceptually presented as a new concept “light”accepting “night and day” as they are.
And the feasibility was fundamentally discussed from a point of materials engineering and culturology.
The following results were obtained.
i) In various pre-modern materials civilizations accepting “night and day” as they are, natural regenerable materials can be pointed out to be chosen as lightmaterials and satisfy the condition of the keeping the consumption not to increase enermously.
ii) The “electric candle” accepting “night and day” as they are, is operated byuse of water and sun light only as energy sources. And it satisfies thecondtion of i).
iii) The “electric candle” accepting “night and day” as they are, is assembledby three of water decomposition by sun light, hydrogen fuel cell, and whitecolor light emitting diode.
iv) SiTiO₃, Sr_0.875 Pb_0.125 TiO₃, and Sr_0.75 Pb_0.25 TiO₃, are selected as optimum waterdecomposition catalysts and are assembled as the catalyst elements by pinconjunction.
v) Thin film of Zr_1-y-z Ca_y Ge_x O_2-y (y=0.2-0.3, z=0.18-0.20) is pointed out tobe able to be used as soild electrolyte operating at normal temperature.
vi) White color light emitting diode is realized by the combination of GaAs (red), GaP_1-0.25N_0.25 (green), and Zn_1-0.055Mg_0.05Se_1-0.05So_0.05 (blue).
Vii) Necessaryd imensionsofelectric light to emit white color light of 1candle for two hours in night after being irradiated by daylight for seven hours are estimatedas follows; Hydrogen fuelcell, white color light emitting diode and waterdecomposition part are respectively 5cm×2cm×2cm, 1.0cm∅×0.65m, and4.0cm∅×150cm.
viii) The concept of “electric candle” can be taken to indicate the “proto type” of white colour light in futue materials civilization.

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Acid leaching of indium-lead-tin alloy wire scrap has been studied. Anexperimental study was excuted to produce leaching liquor for subsequent separationof the concerned metals from the scrap material. Two leaching solutions were investigatedhydrochloric acid and hydrochloric-nitric acid oxidationleaching. Parameters affecting leaching processes such as time, temperature, acid concentration and acid: scrap stoichiometric ratio havebeen evaluated. Results obtained revealed that hydrochloric acid failed toextract metals completely, the maximum extraction efficiency was in the orderof indium 97.1, lead 94.1 and tin 89.2% by using 5M HCl for 6 hours at 95°C, HCl: scrap ratio was 5. Addition of nitric acid as oxidizing agent resulted incomplete extraction for metals, the optimum leaching conditions were conductedby addition of 0.6ml of 1:1HNO₃/g scrap to the leachate of 5M HClfor 1.45 hours at 80°C with HCl: scrap ratio of 2.5. Another advantage forusing of HCl-HNO₃ leaching was that about 71% of the lead content was separatedas pure crystals of PbCl₂ on cooling the resulting solution.

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Magnetic properties and domain structures have been investigated for CO₈₀Cr₁₆ Ta₄ and CO₈₀ Cr₂₀ films with perpendicular magnetic anisotropy. MFMobservation for the remanent magnetization state shows a bright-dark contrastwith a mean wave length of 0.4-0.6μm for the films prepared at the substratetemperature T_s>500K and a maize type domain pattern for the films preparedat room temperature. The magnetization process is understood as the domainwall movement for the films with T_s-300K and the irreversible rotation ofmagnetization of single domain particles for the films with T_s>500K. Therelation between the bright-dark contrast observed by MFM and the magneticmicrostructure is discussed.

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The particle shape affects the grindability of powdered or granular materials. In this work, the compressive crushing of quartz glass in powder bedswere carried out in order to eliminate flakelike or acicular particles and getmore spherical ones. The sample used was 3.5-4mesh (5.66-4.76mm) quartzglass. The shape index defined by (diameter of a circumcircle/thickness) wasmeasured manually with great care by slide caliper. The effect of the mass offeed and the applied load on the shape index of unfractured particles were studied. The relationship between the shape index of unfractured particles and theenergy input in a powder bed or the probability of crushing were calculated experimentally. As a result, it was found that the mean shape index ofunfractured particles decreased with increase in the energy input, that is, increasein the probability of crushing and the experimental equations betweenthese were obtained.

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Catalytic performance of several metallic oxides, i.e., Al₂O₃, Cu₂O, CuO, Cr₂O₃, Fe₂O₃, Mn0₂, Ni₂O₃ and V₂0₅, and some of their partially-reduced samplesto the elimination reaction of NO in NO-CO-CO₂-N₂ and NO-N₂ systemswere examined using a flow-type reactor. The catalytic mechanism in the presentcondition was also discussed.
The experimental results show that most of the metallic oxide samplesgive a catalytic effect on NO/CO reaction with different extent. Fe₂O₃, CuO, Ni₂O₃ and Cr₂O₃ show large catalytic activities, while those of Cu₂O, MnO₂ and Al₂O₃ are quite small. Further, it was found that the pre-reduced Ni₂O₃ samplealso showed remarkable catalytic activity for direct decomposition of NO.

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Effect of tetragonality on the capacitance aging under dc field has been studied. BaTiO₃-based dielectrics with X7R characteristics and Y5V characteristicsfor multilayer ceramic capacitors (MLCCs) with Ni internal electrodes havebeen used for this study. Capacitance change strongly depends on grain sizeand temperature. It is supported that these factors affect tetragonality, and the change of tetragonality causes variation of capacitance change. New equationfor capacitance aging is proposed considering the effect of particle volume, temperature, dc electric field and tetragonality. Effect of internal stress of MLCCs is also discussed. Capacitance change is also a function of internalstress.

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The coarsening behavior of Si precipitates for over-aging stage was observedin A1-1.03mass% Si alloy. The coarsening data were agreement with Lifshiz-Wagner theory on diffusion-controlled coarsening. The influence of this Ostwaldgrowth of Si precipitates on elevated temperature deformation in this alloy wasstudied at temperatures from 473K to 623K in air and at initial strain rates from 7.94×10^-5 to 1.76×10^-2S^-1. It was showed that the steady state flow stress isdecreased with the Ostwald growth of Si precipitates. TEM observation revealed. that the interaction between dislocations and Si precipitates is of attractiveinteractiontype, indicating that the stress field of a dislocation is relaxed atthe Si precipitates/matrix interface.

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The effect of the addition of BaTiO₃ and CaTiO₃ on the electrical propertiesof the SrTiO₃-based varistor have been investigated.The addition of BaTiO₃ and CaTiO₃, especially the addition of BaTiO₃ decreased the grain size of ceramics, nonlinear coefficient (α) and varistor voltage. The capacitance equivalentto the dielectric constant of the varistor was increased by the addition of BaTiO₃.
As the result, the height of Schottkey barrier decreased with the addition of BaTiO₃.
We thought that the decrease of nonlinear coefficient (α) was the result of the decrease in height of Schottky barrier.

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