[en] Electron spin resonance spectra of free radicals formed in the radiolysis of benzene-2,1-diazoquinone-4-sulphonic acid in polycrystalline form were recorded. Two different radical species were found: the first one was stable at 77 K, whereas the second one was formed at higher temperatures. The thermal stability of the latter was investigated in the 20-100 deg C temperature range, and the kinetic parameters for the decomposition process were determined. An appropriate mechanism of radiolysis was proposed. (author)

[en] Electron spin resonance spectra have been used to gain information on the mechanism of radiolysis of aqueous solutions of methylene blue. The identity and behaviour of the semiquinone radicals formed as intermediate reduction products were discussed for strongly acid and for alcaline solutions. In order to obtain information on the radiolytic mechanism in strongly acidic media, irradiation was performed in the presence of various types of scavengers: sodium formate, glucose, succinic acid, hydroquinone and D,L-α alanine. (author)

[en] We present a phenomenological model for the interaction field in ferromagnetic nanowire arrays and use it to obtain the effective anisotropy field of individual nanowires, from the in-plane saturation field of the array. In contrast to other methods which may be used to estimate this parameter, the proposed strategy requires no knowledge of the saturation magnetization nor of the nanowire radius. Applied to three arrays of different compositions, this approach yields an equivalent anisotropy field of the individual nanowires approximately equal to M_s/2, indicating that its origin is the demagnetizing field of the wire