The critical field and specific heat in the electron- and hole-doped graphene superconductors

Doping is one of the most prominent techniques to alter properties of a given material. Herein, the influence of the electron- and hole-doping on the selected superconducting properties of graphene are considered. In details, the Migdal-Eliashberg formalism is employed to analyze the specific heat and the critical magnetic field in the representative case of graphene doped with nitrogen or boron, respectively. It is found that the electron doping is much more favorable in terms of enhancing the aforementioned properties than its hole counterpart. These findings are appropriately summarized by the means of the dimensionless thermodynamic ratios, familiar in the Bardeen-Cooper-Schrieffer theory. To this end, the perspectives for future research on superconductivity in graphene are drawn.Comment: 5 pages, 2 figures, 1 tabl

The superconducting energy gap in the hole-doped graphene beyond the Migdal's theory

In this work we analyze impact of non-adiabatic effects on the superconducting energy gap in the hole-doped graphene. By using the Eliashberg formalism beyond the Migdal's theorem, we present that the non-adiabatic effects strongly influence the superconducting energy gap in the exemplary boron-doped graphene. In particular, the non-adiabatic effects, as represented by the first order vertex corrections to the electron-phonon interaction, supplement Coulomb depairing correlations and suppress the superconducting state. In summary, the obtained results confirm previous studies on superconductivity in two-dimensional materials and show that the corresponding superconducting phase may be notably affected by the non-adiabatic effects.Comment: conference material, 4 pages, 2 figure

Entropy of financial time series due to the shock of war

The concept of entropy is not uniquely relevant to the statistical mechanics but among others it can play pivotal role in the analysis of a time series, particularly the stock market data. In this area sudden events are especially interesting as they describe abrupt data changes which may have long-lasting effects. Here, we investigate the impact of such events on the entropy of financial time series. As a case study we assume data of polish stock market in the context of its main cumulative index. This index is discussed for the finite time periods before and after outbreak of the 2022 Russian invasion of Ukraine, acting as the sudden event. The analysis allows us to validate the entropy-based methodology in assessing market changes as driven by the extreme external factors. We show that qualitative features of market changes can be captured quantitatively in terms of the entropy. In addition to that, the magnitude of the impact is analysed over various time periods in terms of the introduced entropic index. To this end, the present work also attempts to answer whether or not the recent war can be considered as a reason or at least catalyst to the current economic crisis.Comment: 8 pages, 5 figure

FIELD-INDUCED MAGNETIZATION IN Ho0.53Er0.47Co3.04Ni1.95

The magnetization process of Ho0.53Er0.47Co3.04Ni1.95 single crystals was investigated in a field up to 10 T from 4.2 to 300 K as a function of the angle between the c-axis and the magnetic field. The magnetic spin structure is interpreted in a crystal-field-with-exchange-field model

Optimization of fMRI Analysis of Speech Areas in Pre- and Postoperative Diagnostics

Functional magnetic resonance imaging (fMRI) was used to characterize relevant functional areas adjacent to the tumor what has important implications for surgical intervention. The aim of our study was to evaluate the functional areas of Broca and Wernicke responsible for production and understanding the speech which are very important from the point of view patients quality life using different variants of analysis available in the SPM package. Brain activity imaging with FWE controlling seems to be more appropriate than this with un uncorrected thresholds in clinical diagnostic. However analysis in the SPM should be carried out with great care taking into consideration that results can be influenced by parameters used in statistical approaches

Twenty years of medical physics in Silesia

Fizyka Medyczna w Polsce ma już 50 letnią tradycję i wykładana jest na wielu uczelniach. Fizyka Medyczna na Śląsku jako specjalność na kierunku Fizyka po raz pierwszy pojawiła się już ponad dwadzieścia lat temu. Sympozjum „XX-lecie Fizyki Medycznej na Śląsku”, które odbyło się w dniach 6–7 czerwca 2014 roku w Śląskim Międzyuczelnianym Centrum Edukacji i Badań Interdyscyplinarnych, poświęcone było m.in. podsumowaniu tych dwudziestu lat pracy. Przy okazji wspomniano również o osiągnięciach Zakładu Fizyki Medycznej Uniwersytetu Śląskiego, a także interdyscyplinarnej współpracy z innymi uczelniami, klinikami oraz placówkami, zajmującymi się fizyką medyczną w kraju. Sympozjum pokazało także, jak wielkie zmiany w fizyce medycznej zaszły w ciągu tych dwudziestu lat.Medical Physics in Poland has almost 50-year history and many Universities offer education in this field. Medical Physics as a specialty in Physics education in the Silesian University started twenty years ago. From 6th to 7th June 2014 in the Silesian Education and Interdisciplinary Research Center a symposium devoted to “XX years of Medical Physics in Silesia Region” was held. The achievements of the Department of Medical Physics of the Silesian University were discussed, as well as its cooperation with other universities, hospitals and institutions connected to medical physics in Poland. The Symposium showed also the changes in the field of medical physics observed over the last two decades

Structural and Magnetic Properties of Dy(Fe,V,Si)12\text{}_{12} Compounds

An influence of Si on the structural and magnetic properties of Dy(Fe,V,Si)$\text{}_{12}$ compounds is studied. X-ray diffraction shows that these materials crystallise in the tetragonal ThMn$\text{}_{12}$-type structure. An increase in the saturation magnetization, the Curie temperatures and magnetocrystalline anisotropy in the Si substitutional systems is observed when compared with DyFe$\text{}_{12-x}$V$\text{}_{x}$. The magnetic properties depend on the preferential site occupation and concentration of Si and V atoms in these compounds