Properties of graphite prepared from boron-doped pitch as an anode for a rechargeable Li ion battery

Boron-doped graphites were derived from a naphthalene-based pitch mixed with para-xylene glycol (PXG) or dimethyl para-xylene glycol (DMPXG) as a cross-linking agent and three types of boron-containing compounds as a graphitization catalyst, and their anode performances were investigated. The structural analysis of the obtained graphites revealed that PXG functioned mainly as a two-dimensional cross-linking agent during the heat treatment process and DMPXG functioned partially as a three-dimensional. The average interlayer spacing decreased and lattice constant, a₀, and graphitizability increased with increasing the amount of boron atoms added. The result indicated that the carbon atoms were replaced by boron atoms. The anode performance was improved by the enhancement of graphitizability. The structural parameters and anode performance of boron-doped graphites did not depend on the kind of boron-containing compounds but the amount of boron atoms added in pitch and the kind of cross-linking agent.     

The measurement of hydrogen activities in molten copper using an oxide protonic conductor

We have developed a hydrogen sensor for in situ measurements of hydrogen activities in molten copper. The sensor consists of a concentration cell utilizing a proton conductor, CaZr_0.9In_0.1O_3-δ, as the solid electrolyte. The electromotive force (emf) of the cell was generated by both hydrogen and oxygen activity gradients across the cell in a high-temperature region simulating the fire refining processes of copper. However, accurate hydrogen activity in molten copper could be evaluated from the emf if oxygen activity in molten copper was determined simultaneously by another concentration cell and if the hydrogen and the oxygen activities at the reference electrode were known. The performance of the sensor was studied under various conditions. The observed good response and reliability of the sensor show that it should be a powerful tool for improvement of the fire refining process of the molten copper. Theoretical treatment of the calculation of the emf of the concentration cells using a mixed ionic conductor, i.e., protonic and oxide ionic conductor, as solid electrolytes is also discussed briefly.     

Enhancement of serotonergic neural activity contributes to cyclosporine-induced tremors in mice

Patients suffering from inflammatory or dysimmunitary diseases may develop various clinical responses to corticotherapy. This brief article describes the various cellular and molecular mechanisms which underly the genetic, endocrine and immunitary factors involved in corticosensitivity, corticoresistance and corticodependence.     

Heat and mass transfer during crystal growth

Quality of semiconductor and oxide crystals which are grown from the melts plays an important role for electronic and/or optical devices. The crystal quality is significantly affected by the heat and mass transfer in the melts during crystal growth in a growth furnace such as Czochralski or horizontal Bridgman methods. This paper reviews the present understanding of phenomena of the heat and mass transfer of the melts, especially instability of melt convection from the detailed numerical calculation, which helps to understand the melt convection visualized using X-ray radiography. Large scale simulation of melt convection during crystal growth is also reviewed.

Characteristics of flow instabilities of melt convection with a low Prandtl number (ratio between momentum and thermal diffusivities) are also reviewed by focusing on the instabilities of baroclinic, the Rayleigh-Benard and the Marangoni-Benard, from the points of view of temperature, rotating and/or magnetic field effects during crystal growth. Oxygen concentration in grown crystals is also discussed how melt convection affects.     

Life satisfaction and its related factors among institutionalized patients at a Hansen's disease sanatorium

We conducted a questionnaire survey on life styles and health status for 293 patients with Hansen's disease. They were admitted to the wards for disabled and physically able patients of Ohshima Seishoen, in Kagawa prefecture, in 1991. This institution is one of Japan's national leprosy sanitarians. We measured patients' life satisfaction with the Delighted-Terrible Scale. In this report, the distribution of life satisfaction and its associated factors were examined for 210(71.7%) respondents. Factors examined were length of treatment, physical health, and social aspects of life at the sanatorium. The major findings were as follows; 1. The patients aged under 60 had lower proportions of being satisfied with life than those aged 60 or older. The proportions of life satisfaction of the 40-59 age group were 17% for men and 22% for women, while for the 60 or older age groups were 33-44% for men and 41-45% for women. The proportions of life satisfaction in the 60 or older age groups were lower than those of community dwelling elderly persons. 2. We examined factors associated with life satisfaction for the respondents aged 60 or older. Dependence on activities of daily living (ADL) was associated with life satisfaction in some ADL items. Care and aid provided by the staff of the sanatorium may modify the relationship between ADL impairment and life satisfaction. For social aspects of life at the sanatorium, both having networks with family members and having resources other than family were associated with life satisfaction. Going out and positively spending their daily lives were associated with life satisfaction, too. These associations were significant for men. Similar patterns of association were observed for women, but were insignificant. This finding suggests that it is important for the health and medical care staff to pay attention to the social aspects of the life of elderly patients with Hansen's disease.     

Observations of high-field domains in GaxIn1 ? xSb Gunn diodes

The properties of high-field domains in GaxIn1-xSb Gunn diodes (0.4 < x < 0.82) have been studied by measuring the surface potential on the diodes. The domain velocities vary with the Ga composition x, 5.3?6.1×106 cm/s for0.8 > x > 0.55 and 10×106 cm/s for x = 0.4, but they are almost independent of the applied voltage, even if the electron concentration is increased by the impact ionisation in the domain at high applied voltages for the small-x samples.     

Integration of GaAs m.e.s.f.e.t.s and Gunn elements in a 4 bit-gate device

A GaAs m.e.s.f.e.t. and a Schottky electrode-triggered Gunn element have been integrated into a single device which operated as a negative logic inhibitor. A monolithic device of four such inhibitors, connected in cascade, was operated in a stable manner, with a signal delay per gate as small as 40 ps.     

Efect of normal pressure on intrinsic equations in the consistent second approximation theory of thin elastic shells

A linear thin shell theory of the lowest order second approximation is formulated in the case of the application of normal surface loads. A set of intrinsic equations are presented in terms of three stress resultants and three changes of curvature, where the 3-dimensional effect is shown to be necessary. A comparison is made with the refined interior equations derived by John.     

Covalent binding of peroxidized linoleic acid to protein and amino acids as models for lipofuscin formation

The fluorescent substances produced by the reaction of linoleic acid hydroperoxides (LOOH) with ca. 20 different amino acids and bovine serum albumin (BSA) were studied. Only the amino acids, lysine, glycine, arginine, histidine and phenylalanine, gave products with strong fluorescent properties. Products of lysine had a fluorescence intensity of ca. 10 times those of glycine and 100 times those of phenylalanine. The N-acylation of amino acids greatly reduced the fluorescence of the products of the reaction except lysine and arginine. The fluorescence of the products of the reaction of LOOH with N-acetyl BSA was only ca. 25% of the control BSA under the same conditions. It appeared that the substances formed from the reaction of LOOH with BSA were crosslinked polymers as evidenced by column chromatography and polyacrylamide gel electrophoresis. These products were insoluble in common organic solvents and their fluorescent intensities correlated well with the thiobarbituric acid (TBA) test. These observations appear to be highly important in the formation of lipofuscin substances, particularly those associated with the aging pigments which accumulate during aging in mammalian tissues.     

The chemistry of ‘alkali-aggregate’ reaction

To clarify ideas about the alkali aggregate reaction, the reaction between sodium hydroxide and various forms of silica has been studied. Variations with time in the sodium, hydroxyl and silica concentrations in solution have been followed and the volume change of solid silica immersed in solution has been measured.If the silica is an absorbant and reactive form such as silica gel, there is an immediate drop in both sodium and hydroxyl concentrations. Subsequently, as the silica dissolves, sodium concentration rises again. Both the final concentration of dissolved silica and the volume expansion of solid silicate pass through a maximum at an intermediate total Si0₂/Na₂0 mole ratio.