Dielectric and Piezoelectric Properties of Pb(Co1/3Nb2/3)O3-PbTiO3-PbZrO3 Solid Solution Ceramics

Ceramic and piezoelectric properties of the Pb(Co_1/3Nb_2/3)O₃-PbTiO₃-PbZrO₃ system were investigated. The system contains rhombohedral, tetragonal, and pseudocubic phases at room temperature. The triple point is at 0.07Pb(Co_1/3Nb_2/3)O₃-0.43PbTiO₃-0.50PbZrO₃. High dielectric constants (750 to 1500) and radial coupling coefficients (40 to 45%) and low average temperature coefficients of resonant frequency (of the order of 10^-6°C) were obtained for compositions near the morphotropic phase boundary.     

高温流化床的流化特性及结焦非流化行为

在 8 0 mm× 30 mm和 80 mm× 10 mm石英流化床中 ,以低温粘结的高密度聚乙烯和聚丙烯 ,高温粘结的玻璃珠为实验物料 ,研究了高温流化床的流化特性及高温下物料结焦产生的非流化行为。结果表明 ,在本文实验条件下 ,Geldart A、B类高温表面粘结物料 ,床层温度小于其最小粘结温度时 ,床层温度增大 ,颗粒的最小流化速度减小 ;Geldart D类高温表面粘结物料的最小流化速度随温度增加而增大。得出了不同温度下颗粒最小流化速度预测式。床层温度大于最小粘结温度时 ,流化床需在较高的表观气速下才能保持流化 ,床层温度愈高床层流化所需的表观气速越大。研究同时发现 ,颗粒物料的粒径减小 ,流化颗粒的最小粘结温度减小。     

Formation of Myofibrillar Fragments and Reversible Contraction of Sarcomeres in Chicken Pectoral Muscle

SUMMARY— As morphological changes occurred in the pectoral muscles of chicken carcasses during 48 hr storage at 5°C, two notable phenomena were observed: (1) fragmentation of myofibrils and (2) reversible or irreversible contraction of sarcomeres. When blendorized, myofibrils tend to break into small fragments composed of 1-4 sarcomeres with time post-mortem. It was also found that besides an irreversible post-mortem contraction of sarcomeres generally accepted, a reversible contraction can take place under particular conditions.     

A Cooperative Control Algorithm for Multiple SVRs Using Correlation of Measurement Data of Distribution Line

In this paper, a cooperative control algorithm for multiple step voltage regulator (SVR) using correlation of measurement data of distribution line is proposed. Conventionally, the control time constant of a SVR placed on the feeder end side was set slower than a SVR placed on the substation side. The unnecessary tap movement of SVR was reduced by this setting. In this case, on the condition that “the photovoltaic power generation output of the feeder end fluctuates” and “only SVR of the end side works”, it is a problem that control of SVR becomes slow. By the proposed method, the SVR settled in end side of a feeder can change its tap rapidly only if the SVR settled in sending side of a feeder will not change its tap by using proposed method. The features of the method are followings: (1) to estimate tap change possibility of the sending side SVR using correlation model of both of the SVR, (2) only use local measurement data of the SVRs for tap change control. By the proposed method, unnecessary tap change operation and lag of tap control are reduced without communication networks.     

Antioxidant Effect of Riboflavin Tetrabutylate in Emulsions

The antioxidant effects of riboflavin tetrabutylate in emulsions in the dark and under irradiation were studied, as was the effect of racemic (rac) α-tocopherol on the antioxidant action. Riboflavin tetrabutylate had an antioxidant effect in the dark, but an oxidative effect when irradiated, perhaps because the activated oxygen and hydrogen peroxide produced induced lipid peroxidation. The effect of racα-tocopherol on the antioxidant action of riboflavin tetrabutylate was synergistic in the dark. The results showed that riboflavin tetrabutylate was satisfactory as an antioxidant when the emulsion was protected from light and that the effect was increased by the addition of racα-tocopherol.     

Structural Analysis of SiO2-Al2O3 Glasses

The structure of SiO₂-Al₂O₃ glasses with up to 60 wt% Al₂O₃ was investigated using the radial distribution function together with the correlation method based on X-ray scattering intensity data. Radial distribution curves are interpreted on the basis of glass-in-glass separation with the constituents of SiO₂-rich and Al₂O₃-rich glasses. The structure of the Al₂O₃-rich glass has a short-range ordering similar to the crystal structure of mullite. The calculated S- i (S) curve of this model gives good agreement with the observed one.     

AGGLOMERATION BEHAVIOR IN A BUBBLING FLUIDIZED BED AT HIGH TEMPERATURE

Minimum fluidization velocity and agglomeration behavior were investigated at high temperature in an 80?×?30?mm two-dimensional quartz fluidized bed and in an 82?mm i.d. circular fluidized bed. Bed materials tested were two sizes of glass beads as well as three sizes of fluidized bed combustor (FBC) ash. The minimum fluidization velocity decreased with increasing bed temperature, whereas the minimum sintering fluidization velocity increased with the bed temperature. The sintering of glass beads belongs to visco plastic sintering, the first type. FBC ash agglomerate has higher amounts of SiO₂, Al₂O₃, Na₂O, K₂O, and SiO₂ than in the original ash, indicating that low melting eutectics were formed and that the liquid phase in a silicate system was formed. The agglomeration of FBC ash belongs to the second type, an excessive quantity of liquid being formed by melting or chemical reaction.     

Vacuum Vaporization in the System MgO-Cr2O3

The vaporization of the system MgO-Cr₂O₃ was studied in a vacuum of 10⁻⁵ torr (10⁻³N/m²) at 1500° to 1700°C using the Langmuir and Knudsen methods. It was found that the phases in the system vaporize nearly congruently and the logarithm of the vaporization coefficient, α, of MgCr₂O₄ increases linearly with increasing reciprocal temperature. Alpha tends to unity at a temperature near the melting point (2525±23°C). The additivity rule can be applied to the Langmuir vaporization rates on the basis of the surface area ratios of the phases in the 2-phase system MgO-Cr₂O₃. The enthalpies of vaporization of MgCr₂O₄ were 695.0 and 549.2 kcaVmol for activated and equilibrium processes, respectively.