No abstract

No abstract

No abstract

We theoretically investigated the adequate geometrical configuration of a saddle-shaped pick-up coil for the accurate measurement of the ac losses in oxide superconducting thin wires with large anisotropy. Defining the ratio of the apparent signal due to the magnetic moment in sample wires, which is detected by a saddle-shaped pick-up coil, to the actual one as a detection ratio, we calculated the dependences of the detection ratio on the height, width and length of the straight and opening parts of a saddle-shaped pick-up coil. We found out that it is possible to obtain the actual magnetization without compensation by supposing that the effective length of sample wires is equal to that of the straight part of a saddle-shaped pick-up coil and by considering that the signal which is detected by the opening part compensates for the shortage of the signal which is detected by the straight part. Finally, the recommendable dimensions of a saddle-shaped pick-up coil for the measurement of ac losses in currently developed oxide superconducting wires were concretely shown.

Copper and silver test specimens were subjected to indoor exposure tests carried out at 23 sites in Tokyo, Bandung, Singapore, and Bangkok. At the same time, the deposition rates of H2S, SO2, NO2, HC1, and NaC1 particles which had deposited on the sampling devices were measured. Corroded specimen surfaces were examined by electron probe microanalysis, Auger electron spectroscopy, x-ray photoelectron spectroscopy, infrared spectroscopy, and x-ray diffraction, and corrosion rates were measured by the electrolytic reduction method. On the surface of Cu, oxides, hydroxides, chlorides, sulfates, sulfides, nitrates, and carboxylates were detected. The Cu corrosion rate correlated with the HC1 deposition rate. On the surface of Ag, sulfides, sulfates, chlorides, and nitrates were found in the environments slightly polluted with H2S, but Ag2S only was found in the environments heavily polluted with H2S. The Ag corrosion rate showed a correlation with the H~S deposition rate.