Giant magneto-impedance in heterogeneous microwires
Recent results concerning the giant magneto-impedance effect, GMI, in magnetic microwires having diameter in the range of a few micrometers and heterogeneous character are introduced in this work. Two types of microwires have been studied, namely, (i) magnetic microwires covered by insulating Pyrex glass coating and (ii) copper wires covered by electrodeposited magnetic microtubes. The magnetic anisotropy distribution in each type of microwire is correlated with giant magneto-impedance. While the main source of anisotropy in glass coated microwires is of magnetoelastic origin created by the stresses induced during quenching and by the coating, in the case of the microtubes the origin is the columnar growth during the electrodeposition. The influence on GMI of various treatments that modify the anisotropy is analyzed. Heterogeneous microwires with different thicknesses of insulating coating and of magnetic tube are analyzed.
Effect of Nanocrystallization on Magnetic Properties 
and GMI Effect of Fe-rich Microwires
We studied the giant magnetoimpedance (GMI) effect and magnetic properties of Finemet-type FeCuNbSiB microwires. We observed that the GMI effect and magnetic softness of glass-coated microwires produced by the Taylor–Ulitovski technique can be tailored by controlling the magnetoelastic anisotropy of as-prepared FeCuNbSiB microwires, and can also be considerably improved either by heat treatment and/or choosing the suitable fabrication conditions. We observed a considerable magnetic softening of the microwires after the appropriate annealing. This magnetic softening correlates with the devitrification of amorphous samples. Amorphous Fe-rich microwires exhibited a low GMI effect (GMI ratio below 5%). A considerable enhancement of the GMI effect (GMI ratio up to 100%) has been observed in heat-treated microwires with nanocrystalline structure.
In search of optimum chest radiography techniques.
A nation-wide study of chest radiography in Sweden had previously revealed a large variation in the physical and technical factors involved, in particular the radiation dose. In this study the image quality could not be assessed unambiguously. The aim of the present study was to try to establish a correlation between visual grading of radiographs and physical and technical factors in order to find the optimum chest X-ray system. The physical and technical performance of 24 chest units was evaluated. Radiographs were taken of an anthropomorphic chest phantom supplied with test structures simulating various pathologies. Image quality was assessed by visual grading analysis of the radiographs. The physical and technical parameters of the units rated best were used to exemplify good radiographic practice. The results were in agreement with the recommendations issued by the Commission of the European Communities (CEC). It was also shown that low radiation dose is compatible with high-quality radiographic imaging of the chest.