A study on the effect of fine mineral powders with distinct vitreous contents on the fluidity and rheological properties of concrete

This paper presents an investigation on the effects of fine mineral powders on the fluidity and rheological properties of concrete. It was observed that the fluidity of concrete increased noticeably, and the plastic viscosity decreased, when vitreous powders were substituted partially for cement. It was found that vitreous powders have a strong dispersion effect on the fluidity and rheological properties of concrete, and this effect can be correlated with the vitreous content of the powders incorporated.     

The Direct Spectroscopy of Positronium Hyperfine Structure Using a Sub-THz Gyrotron

Positronium is an ideal system for research on Quantum Electrodynamics (QED), especially in a bound state. A discrepancy of 3.9 standard deviations has been found between the measured hyperfine structure (Ps-HFS) and the QED predictions. This may be due to the contribution of unknown new physics or common systematic effects in previous measurements, in all of which the Zeeman effect was used. We propose a new method to directly measure the Ps-HFS using a high power gyrotron. We compare two resonators which have been developed to supply sufficient power to drive the direct transition, a Fabry-Pérot resonator and a ring resonator with a diffraction grating. We plan to perform first direct measurement of Ps-HFS within the next six months.     

Adsorption and photocatalytic decomposition of methylene blue on mesoporous metallosilicates

Mesoporous silica and mesoporous metallosilicates with Al, Ti and Fe as foreign metal species were successfully synthesized by the rapid room temperature method. Mesoporous metallosilicates with low contents of foreign metals possessed high surface area (S_a), large mesopore volume (V_mp) and highly ordered hexagonal mesoporous structure. Increases in foreign metal contents caused disordering the mesoporous structures and lowering the S_a and V_mp values. Bleaching of aqueous methylene blue (MB) by mesoporous silica and metallosilicates was investigated. Mesoporous aluminosilicate and ferrosilicate with cation-exchangeable ability showed the excellent property for the adsorption of MB of cationic dye, while mesoporous ferrosilicate and titanosilicate which absorbed UV lights catalyzed the photocatalytic decomposition of MB under UV-illumination.     

Identification and characterization of a major lysosomal membrane glycoprotein, LGP85/LIMP II in mouse liver

To develop a less reactogenic but equally immunogenic vaccine, this study of 91 human volunteers compared the safety and immunogenic potency of a new, cell culture-derived vaccinia virus vaccine administered intradermally and intramuscularly with the licensed vaccinia vaccine administered by scarification. Cutaneous pox lesions developed in a higher proportion of scarification vaccinees. Scarification and intradermal vaccine recipients who developed cutaneous pox lesions had more local reactions but also achieved significantly higher cell-mediated and neutralizing antibody responses than those who did not develop pox lesions. Although less reactogenic, intradermal or intramuscular administration of vaccinia vaccine without the concomitant development of a cutaneous pox lesion induced lower immune responses.     

Time‐frequency analysis of a pressure wave caused by impulse tree using wavelet transform

This paper describes results of time‐frequency analysis of a pressure wave caused by impulse tree extension using wavelet transform. Pressure waves were measured by a piezo sensor which was located on the back of the plane electrode when high‐voltage nanosecond pulses were applied to a point electrode in a low‐density polyethylene block. Frequency of the pressure wave from induced charges on the plane electrode was higher than that of the pressure wave from tree. In addition, the frequency of the pressure wave from tree tended to decrease with increasing gap length because of the dispersion of the pressure wave during its propagation. When a large tree extension occurred between a 5‐mm gap, pressure waves of about 10 MHz propagated from the tree tip and a pressure wave of 1 MHz propagated from the tree stem. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 142(1): 1–7, 2003; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10097     

The effect of phenobarbital on the multiple neuronal activity in the hippocampus of El mice

Phenobarbital (PB) (5, 25 and 50 mg/kg), which was administered intraperitoneally to evaluate the effect of it on El mice, inhibited convulsive seizures dose-dependently. On the other hand, microelectrodes were implanted continually into the hippocampus of El mice, after which changes in the neuronal activity caused by a seizure were studied, as well as the effect of PB (5, 25 and 50 mg/kg) on the neuronal activity. The neuronal activity increased during the convulsive seizure when compared to the neuronal activity as the mice moved about freely. Further, after the convulsive seizure, five or six groups of bursts were seen periodically. PB reduced the neuronal activity dose-dependently judging by the number of bursts in the initial group of bursts.     

Banet — a local area network for distributed data processing

A broadcast architecture network (Banet) suitable for distributed data processing is proposed. One feature of Banet is that the broadcast-within-a-group function is supported not only by the datalink level but by the transport or session-level network structure. The commitment control scheme is included in the network protocol. Design goals, physical structure and protocols are discussed.     

The ductile to brittle transition in tin-lead alloys near melting temperatures

Tensile tests were carried out on tin containing up to 2.0 wt pct lead between 160 and 220 °C at strain rates of 8.3 x 10^-3 and 8.3 x 10^-4 s^-1. Both as-cast and heavily deformed samples were examined. The samples exhibited a ductile-brittle transition at a temperatureTDB below the equilibrium solidus temperature of the corresponding alloy.TDB was found to increase with decreasing strain rate and was sensitive to the structure of the test sample. The smooth faceted surface of the brittle failures indicated the presence of a liquid layer at the grain boundaries at failure. Homogenizing the samples prior to testing markedly increasedTDB to near the solidus temperature. Formerly Visiting Scientist, Department of Metallurgical Engineering, University of British Columbia