Wear-resistant magnetic head using amorphous alloy material

An audio recording/playback head using an amorphous (Fe-Co-Ru-Cr) ₇₅(Si-B)₂₅ alloy was developed. Compared with a commercial Sendust head, three excellent features were observed. The wear of the amorphous alloy head when used with γ-Fe₂O ₃ is two-thirds that of the Sendust head. The output level at high-frequency (14 kHz) is 5 dB higher than that of the Sendust head. The bias current for the amorphous alloy head is half that of the Sendust head     

Efficient synthesis and magnetic properties of triphenylamine bearing three nitronylnitroxide radicals

Improved synthesis and reinvestigation of the magnetic properties of triphenylamine bearing three nitronylnitroxide radicals (1) were carried out. Single crystal X-ray crystallographic analysis of 1 established that its molecular shape had a C₃-symmetry. Our newly prepared 1 showed different physical properties from those of reported. SQUID measurements of 1 showed that each of the three spins of 1 behaved independently at room temperature. In contrast, the three spins coupled antiferromagnetically at lower temperature as low as ca. 1.8 K. These spin behaviors can be explained by a regular triangular antiferromagnetic model (J/k_B = ?3.3 K) and interpreted as a spin frustration system.     

A case of neurologic type of Wilson's disease with increased aluminum in liver: comparative study with histological findings to metal contents in the liver

Histological findings and metal contents in the liver were studied in a patient with neurologic type of Wilson's disease. Copper and aluminum contents in the biopsied liver of the patient with Wilson's disease were measured simultaneously by neutron activation analysis at Research Reactor Institute, Kyoto University. Four cases of adult cirrhosis were selected as the control for cirrhosis and five cases of adult liver as the control for neurologically normal. The biopsied liver showed markedly increase in the copper content (814.4 micrograms/g: dry weight) and extremely high content of aluminum (479.4 micrograms/g: dry weight), compared to those of the controls. On the other hand, macroscopically no cirrhosis was observed and the characteristic appearances of macronodular cirrhosis failed to detect histologically. Interestingly the fibrosis or inflammation of the liver was seen faintly. It is likely that toxic metals in the liver such as aluminum, copper and manganese might be implicated in the pathogenesis of neurologic type of Wilson's disease.