As known, the magnetic properties of AGCMs are determined by the radial, azimuthal and axial internal stresses induced during both the preparation process and the suitable thermal treatments of these microwires. In this paper we have proposed a theoretical model in order to determine the total internal stresses induced during the dc joule-heating thermal treatment (heating–crystallization–cooling). In this view (i) we have started from the internal stress values obtained in the preparation process, (ii) we have considered the supplementary axial tensile stresses due to the mechanical drawing of the microwire during the preparation process and (iii) we have taken into account the difference between the thermal expansion coefficients of metal and glass. We have found that (i) the maximum value of the axial stresses obtained after the thermal treatment is bigger than that obtained in the preparation process, the difference being about 450 MPa, (ii) the maximum values for the azimuthal and radial stresses decrease by and  MPa respectively, (iii) the dimensions of the cylindrical inner core increase significantly (by ), which involves an increase of the degree of magnetic order in the AGCMs and consequently leads to the appearance of a large Barkhausen effect (LBE) in low axially applied magnetic fields and (iv) the reduced remanence increases from 0.90 to 0.95.

The Italian National Institute of Ionizing Radiation Metrology (ENEA-INMRI) has designed and built a graphite calorimeter that, in a water phantom, has allowed the determination of the absorbed dose to water in medium-energy x-rays with generating voltages from 180 to 250 kV. The new standard is a miniaturized three-bodies calorimeter, with a disc-shaped core of 21 mm diameter and 2 mm thickness weighing 1.134 g, sealed in a PMMA waterproof envelope with air-evacuated gaps. The measured absorbed dose to graphite is converted into absorbed dose to water by means of an energy-dependent conversion factor obtained from Monte Carlo simulations. Heat-transfer correction factors were determined by FEM calculations. At a source-to-detector distance of 100 cm, a depth in water of 2 g cm(-2), and at a dose rate of about 0.15 Gy min(-1), results of calorimetric measurements of absorbed dose to water, D(w), were compared to experimental determinations, D wK, obtained via an ionization chamber calibrated in terms of air kerma, according to established dosimetry protocols. The combined standard uncertainty of D(w) and D(wK) were estimated as 1.9% and 1.7%, respectively. The two absorbed dose to water determinations were in agreement within 1%, well below the stated measurement uncertainties. Advancements are in progress to extend the measurement capability of the new in-water-phantom graphite calorimeter to other filtered medium-energy x-ray qualities and to reduce the D(w) uncertainty to around 1%. The new calorimeter represents the first implementation of in-water-phantom graphite calorimetry in the kilovoltage range and, allowing independent determinations of D(w), it will contribute to establish a robust system of absorbed dose to water primary standards for medium-energy x-ray beams.

The annealing of magnetic amorphous wires by passing a dc current through them leads to an improvement in their magnetic properties. A theoretical model is proposed for the calculation of the radial and temporal distribution of the temperature produced by passing a dc current through the wire by taking into account the linear temperature dependence of the electrical resistivity. The higher the value of the dc current, the faster the equilibrium temperature is reached. The temperature distribution is approximately constant in the cross‐section of the wire. The calculated temperature values are experimentally verified through magnetic measurements using a fluxmeter on amorphous wires with known Curie temperature. It is ascertained that the theoretical results are in good agreement with the experimental ones.

Hyperthermia induced by the heating of magnetic particles (MPs) in alternating magnetic field receives a considerable attention in cancer therapy. An interesting development in the studies dedicated to magnetically based hyperthermia is the possibility to control the temperature using MPs with selective magnetic absorption properties. This paper analyzes the temperature field determined by the heating of MPs having low Curie temperature (a FeCrNbB particulate system) injected within a malignant tissue, subjected to an ac magnetic field. The temperature evolution within healthy and tumor tissues was analyzed by finite element method simulations in a thermo-fluid model. The cooling effect produced by blood flowing in blood vessels was considered. This effect is intensified at the increase of blood velocity. The FeCrNbB particles, having the Curie temperature close to the therapeutic range, transfer the heat more homogeneous in the tumor keeping the temperature within the therapeutic range in whole tumor volume. Having the possibility to automatically control the temperature within a tumor, these particle type opens new research horizons in the magnetic hyperthermia.

In the last years, hyperthermia induced by the heating of magnetic nanoparticles (MNPs) in an alternating magnetic field received considerable attention in cancer therapy. The thermal effects could be automatically controlled by using MNPs with selective magnetic absorption properties. In this paper, we analyze the temperature field determined by the heating of MNPs, injected in a malignant tissue, subjected to an alternating magnetic field. The main parameters which have a strong influence on temperature field are analyzed. The temperature evolution within healthy and tumor tissues are analyzed by finite element method (FEM) simulations in a thermo-fluid model. The cooling effect produced by blood flow in blood vessels from the tumor is considered. A thermal analysis is conducted under different distributions of MNP injection sites. The interdependence between the optimum dose of the nanoparticles and various types of tumors is investigated in order to understand their thermal effect on hyperthermia therapy. The control of the temperature field in the tumor and healthy tissues is an important step in the healing treatment.