Search for Chelyabinsk Meteorite Fragments in Chebarkul Lake Bottom (GPR and Magnetic Data), Journal of Telecommunications and Information Technology, 2017, nr 3

The paper summarizes experimental efforts of the Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation (IZMIRAN) undertaken in search of the biggest part of Chelyabinsk meteorite in the bottom of lake Chebarkul, South Ural, Russia, and to estimate the ecological effects of its subsequent excavation

Angle Magnetization Rotation Method for Characterizing Co-Rich Amorphous Ferromagnetic Microwires

A low-frequency model of the magnetization reversal of a microwire is developed for those cases when the microwire magnetization response can go beyond the linear approximation. The analysis of the influence of external magnetic fields on the process of magnetization reversal of the microwire, including the hysteresis mode, was performed. The characteristic dependences of the amplitude of the electromotive force, U2f, arising in the pick-up coil wound around the microwire are obtained. It was established that, in the region of relatively small-acting circular and longitudinal magnetic fields, the U2f signal could have a region with the opposite sign. An extended small-angle magnetization rotation method was used to verify the proposed model and test glass-coated, amorphous, Co-rich microwires. During the experiments, the amplitude of the second harmonic, U2f, arising in the pick-up coil when an alternating electric current with the frequency f flows through the microwire, was measured as a function of the applied longitudinal magnetic field at various mechanical tensile stresses. The effective anisotropy field, the magnetostriction constant, and the residual quenching stress of the investigated microwires were determined by comparing the theoretical and experimental data

Application of Ferromagnetic Microwires as Temperature Sensors in Measurements of Thermal Conductivity

A method for the determination of the thermal conductivity of polymer composite materials by using Co-based ferromagnetic microwires is proposed. Microwire segments were integrated into the samples of studied materials during their manufacture and used as current microheaters and resistance thermometers. As a representative material, we used a material based on nitrile butadiene rubber filled with hexagonal boron nitride after its low-temperature carbonization and a significant increase in thermal conductivity. The thermal conductivity values of composite samples determined during experiments varied from 1.0 W/(m·K) to 1.8 W/(m·K) depending on the percentage of boron nitride. The thermal conductivity values obtained are in good agreement with the estimates obtained by the standard laser flash method