We discovered the first superconducting high-entropy alloy the Ta-Nb-Hf-Zr-Ti system [3], showing a high superconducting transition temperature (for a metallic system) of 7.3 K and a large upper critical field of 8.2 T. The superconducting phase was demonstrated to be close to a BCS–type, which employs an electron–phonon coupling to create Cooper pairs.
COBISS.SI-ID: 27907879
The capabilities of non-destructive testing (NDT) methods for defect detection in civil engineering are characterized by their different penetration depth, resolution and sensitivity to material properties. Therefore, in many cases multi-sensor NDT has to be performed, producing large data sets that require an efficient data evaluation framework. In this work an image fusion methodology is proposed based on unsupervised clustering methods. Their performance is evaluated on ground penetrating radar and infrared thermography data from laboratory concrete specimens with different simulated near-surface defects. It is shown that clustering could effectively partition the data for further feature level-based data fusion by improving the detectability of defects simulating delamination, voids and localized water. A comparison with supervised symbol level fusion shows that clustering-based fusion outperforms this, especially in situations with very limited knowledge about the material properties and depths of the defects. Additionally, clustering is successfully applied in a case study where a multi-sensor NDT data set was automatically collected by a self-navigating mobile robot system.
COBISS.SI-ID: 16909145
Atomic magnetometers are emerging as an alternative to SQUID magnetometers for detection of biological magnetic fields. They have been used to measure both the magnetocardiography (MCG) and magnetoencephalography (MEG) signals. One of the virtues of the atomic magnetometers is their ability to operate as a multi-channel detector while using many common elements. Here we study two configurations of such a multi-channel atomic magnetometer optimized for MEG detection. We describe measurements of auditory evoked fields (AEF) from a human brain as well as localization of dipolar phantoms and auditory evoked fields. A clear N100m peak in AEF was observed with a signal-to-noise ratio of higher than 10 after averaging of 250 stimuli. Currently the intrinsic magnetic noise level is 4 fTHz$^{-1/2}$ at 10 Hz. We compare the performance of the two systems in regards to current source localization and discuss future development of atomic MEG systems.
COBISS.SI-ID: 10306644
14N nuclear quadrupole resonance (NQR) in two known polymorphs of famotidine was measured. At room temperature, seven quadrupolar sets of transition frequencies (ν+, ν-, and ν0) corresponding to seven different nitrogen sites in the crystal structure of each of the two polymorphs were found. This confirms the expected ability of NQR to distinguish polymorph B from its analog A. NQR can also measure their ratio in a solid mixture and in the final dosage form, that is, a tablet. The NQR frequencies, line shapes, and tentative assignation to all seven molecular 14N atoms were obtained. Unravelment of these two entangled NQR spectra presents a valuable contribution to the NQR database and enables studies of some possible correlations therein. Moreover, nondestructive 14N NQR studies of commercial famotidine tablets can reveal some details of the drug fabrication process connected with compression.
COBISS.SI-ID: 17097049
We present the synthesis, characterization, and magnetic properties of hematite particles in a peculiar “nanomedusa” morphology. Each particle represents a nanodimensional “hairy” ferromagnet in a very broad temperature interval, extending much above the room temperature. We demonstrated that such nanoparticles can be used as a medium for thermal memory cell.
COBISS.SI-ID: 28173095