Interfacial diffusion between Ni–Zn–Cu ferrite and Ag during sintering

The interfacial diffusion between Ni–Zn–Cu ferrite and Ag during sintering in the temperature range of 850–950°C was investigated utilizing the scanning electron microscopy-energy–dispersive X-ray analysis technique. It was found that diffusion increased with an increase in the sintering temperature. Furthermore, some impurities in the ferrite powders, especially SiO2 and NH4Cl, promoted the interfacial diffusion. The interfacial diffusion of Ag can be explained by the liquid-phase formation at the grain boundary in the sintered ferrite. © 1998 chapman & Hall     

Phase stability of B1-type carbides in nickel-based alloys

In nickel-based superalloys, the B1-type monocarbides contain several kinds of transition elements. At elevated temperatures, the monocarbides transform to other carbides, such as M₂₃C₆ and M₆C as a result of the reaction with the alloy. The phase stability of monocarbides was investigated by X-ray diffraction techniques. The degree of stability is strongly affected by the composition of the monocarbides and is related generally to the magnitude of the lattice parameter of the monocarbides. That is, the larger the lattice parameters of the monocarbides, the higher their stability in nickel-based alloys.     

Learning control and knowledge representation

Practising to operate an unknown system and observing the input and output of the system, in a sense, helps to optimally control that system. The acquired knowledge, is, in turn, used to solve future analogous control problems. This means that it is very important to know how to memorize the acquired knowledge and to utilize it for learning. In this paper, we propose a new knowledge representation and reasoning method and develop a learning machine (KBLC: Knowledge-Based Learning Controller) by using them. A simple implementation has been constructed that demonstrates the feasibility of building such a machine.     

Treatment of the porphyrias

There are seven porphyrias which are caused by defective functions of the enzymes in the haem biosynthesis. The clinical classification of porphyrias are divided into three types which are neuroporphyria, neurocutaneous porphyria and cutaneous porphyria. For acute porphyric attack of neuroporphyria and neurocutaneous porphyria, the treatments of choice are administration of glucose and/or hematin, haem arginate and tinprotoporphyrin. Porphyria cutanea tarda in cutaneous porphyria is controlled by removal of iron by phrebotomies or low-dose chloriquine. A novel approach of intravenous administration of interferon may be useful to control the associated case of chronic hepatitis type C. Skin symptoms in erythropoietic protoporphyria can be alleviated with beta carotene. Hepatic failure due to protoporphyria may need a liver transplantation. Cimetidine, a H2-receptor antagonist, may be useful in the treatment of acute porphyric attack and in remission stage in neuroporphyrias, neurocutaneous porphyrias and cutaneous porphyrias such as porphyria cutanea tarda and protoporphyria.     

UPGRADING OF COAL-DERIVED LIQUIDS. 1. CATALYTIC ACTIVITIES OF ZEOLITE CATALYSTS AND COMMERCIAL HDS CATALYSTS

The applicability of various zeolite catalysts and commercial HDS catalysts to the secondary hydrotreatment of coal-derived liquids was examined in relation to the chemical structure of upgraded liquids. The catalytic activities of zeolite catalysts for HI conversion is lower than are the activities of Ni-Mo, Ni-Co-Mo, Co-Mo and Ni-W catalysts. However, as regards hydrogenation and the removal of nitrogen, zeolite catalysts such as natural clinoptilolite and mordenite have almost the same activity as do Co-Mo and Ni-W catalysts. As to the removal of oxygen, it was proved that zeolite catalysts had a functionality to remove oxygen as COx gas, and HDS catalysts had a high activity for hydrodeoxygenation.     

Color error from an RGB‐stripe pixel structure

Abstract— Most direct‐view color displays have a sub‐pixel structure similar to the RGB‐stripe structure. The video data for R and B are produced on the condition that they are reproduced at the same position as G but they are displayed on the screen with 1/3 of a pixel separation from the corresponding G pixel. This pixel structure thus entails a convergence error of 1/3 of a pixel. The modified s‐CIELAB method was applied to investigate color errors produced by the RGB‐stripe pixel structure. The results show that the pixel structure can degrade the image quality even for a viewing distance where the pixel structure is not visible because the color difference caused by the structure has a low‐frequency component and the human vision can detect it. The same method was applied to the convergence error and it was shown that the necessary convergence accuracy is around 1/4 of a pixel.     

Characterization of miniaturized one-side-electrode-type fluid-based inclinometer

In this study, electrical double-layer theory is applied to realize a one-side-electrode-type fluid-based inclinometer combined with complementary metal oxide semiconductor (CMOS) circuitry. Substrate penetration lithography was applied in the fabrication of high-aspect-ratio SU-8 container molds, and molds with heights 1.0 mm were fabricated. Polydimethylsiloxane (PDMS) was used as the container material, and electrodes were fabricated on a ceramic substrate. Considering the electrical double-layer property, low surface tension, the dielectric constant and the problem of volatilization, methanol and propylene carbonate were tested as electrolytes. A charge-balanced capacitance–voltage (C–V) conversion circuit was designed as a detection circuit for this sensor and it was fabricated using 0.35 μm CMOS technology. The sensor part and detection circuit were integrated in one ceramic packaging for realize a miniaturization of inclination sensor system. To overcome the surface tension of the PDMS surface, silicone oil was injected in the container to cover the entire inner surface so that the movement of solution in the container became smooth. The linearity of the analog output of ±60° inclination for container dimensions of Ø 4.0 mm × 1.0 mm (diameter × thickness) was less than 6%/F.S. The minimum moving angle and response time were 0.4° and 0.9 s, respectively, when propylene carbonate was used as the electrolyte. The change in temperature did not affect the output voltage of the sensor between 0 and 50 °C. The effect of vibration was demonstrated in this paper.     

Estimation of formation mechanism of spherical fine ZrO2-SiO2 particles by ultrasonic spray pyrolysis

Spherical fine ZrO₂-SiO₂ (11) particles were synthesized from a hydrolysed mix-solution of Si(OC₂H₅)₄ and ZrOCI₂ · 8H₂O by ultrasonic spray pyrolysis, and the formation mechanism of the particles discussed. All of the resultant particles identified as t-ZrO₂ and amorphous SiO₂ with an atomic order dispersion were spherical, and mainly of diameter 0.8 to 1.0m. It was estimated that the three-dimensional ladder siloxane chains containing an equimolar Zr⁴⁺ homogeneously dispersed were formed by hydrolysis, and an atomized droplet itself converted into an isolated ZrO₂-SiO₂ (11) particle without aggregation.