Depth concentrations of deuterium ions implanted into some pure metals and alloys

Pure metals (Cu, Ti, Zr, V, Pd) and diluted Pd-alloys (Pd-Ag, Pd-Pt, Pd-Ru, Pd-Rh) were implanted by 25 keV deuterium ions at fluences in the range (1.2{\div}2.3)x1022 D+/m2. The post-treatment depth distributions of deuterium ions were measured 10 days and three months after the implantation using Elastic Recoil Detection Analysis (ERDA) and Rutherford Backscattering (RBS). Comparison of the obtained results allowed to make conclusions about relative stability of deuterium and hydrogen gases in pure metals and diluted Pd alloys. Very high diffusion rates of implanted deuterium ions from V and Pd pure metals and Pd alloys were observed. Small-angle X-ray scattering revealed formation of nanosized defects in implanted corundum and titanium.Comment: 12 pages, 9 figure

Superexchange Interaction in Insulating EuZn2_{2}P2_{2}

We report magnetic and transport properties of single-crystalline EuZn$_{2}$P$_{2}$, which has trigonal CaAl$_2$Si$_2$-type crystal structure and orders antiferromagnetically at $\approx$23~K. Easy $ab$-plane magneto-crystalline anisotropy was confirmed from the magnetization isotherms, measured with a magnetic field applied along different crystallographic directions ($ab$-plane and $c$-axis). Positive Curie-Weiss temperature indicates dominating ferromagnetic correlations. Electrical resistivity displays insulating behavior with a band-gap of $\approx\,$0.177~eV, which decreases to $\approx\,$0.13~eV upon application of a high magnetic field. We explained the intriguing presence of magnetic interactions in an intermetallic insulator by the mechanism of extended superexchange, with phosphorus as an anion mediator, which is further supported by our analysis of the charge and spin density distributions. We constructed the effective Heisenberg model, with exchange parameters derived from the \textit{ab initio} DFT calculations, and employed it in Monte-Carlo simulations, which correctly reproduced the experimental value of N\'eel temperature

Jakość życia oraz jej predyktory wśród pacjentów neurologicznych — systematyczny przegląd badań

Quality of life is an important aspect in the fields of medicine and health sciences. It is presented as a complex concept. Therefore, it is presented in various ways. Its interpretation and definition depends mainly on the discipline and area of study. Very often, the quality of life is also defined in the context of the well-being that a person experiences during his life. It depends on the state of health. It can take into account a wide variety of problems, because neurological diseases bring about such unwanted effects as pain, the need for medical and rehabilitation stays, social isolation, and one of the worst consequences, i.e. shortening life expectancy. Therefore, it is important to conduct research on the quality of life among neurological patients. The results obtained from the conducted and continued research on large groups of patients could constitute a specific compendium of knowledge about the situation of patients, their needs and the perceived quality of life. Therefore, the aim of this study is to present research on the assessment of quality of life and its predictors among neurological patients. (JNNN 2020;9(3):114–118)Jakość życia jest ważnym aspektem w dziedzinie medycyny i nauk o zdrowiu. Ukazywana jest ona jako pojęcie złożone. Dlatego też prezentowana jest w różnorodny sposób. Jej interpretacja oraz definiowanie zależy w głównej mierze od dyscypliny i obszaru nauki. Bardzo często jakość życia definiowana jest także w kontekście dobrostanu jakiego człowiek doświadcza w ciągu swojego życia. Uwarunkowana jest ona od stanu zdrowia. Może uwzględniać dużą różnorodność problemów, ponieważ choroby neurologiczne przynoszą tak niechciane skutki jak ból, konieczność pobytów w placówkach medycznych oraz rehabilitacyjnych, izolację społeczną, oraz jedną z najgorszych konsekwencji, czyli skrócenie przewidywanej długości życia. Istotne jest zatem prowadzenie badań nad jakością życia wśród chorych neurologicznych. Uzyskane wyniki z prowadzonych oraz kontynuowanych badań na dużych grupach pacjentów mogłyby stanowić swoiste kompendium wiedzy na temat sytuacji chorych, ich potrzeb oraz odczuwanej jakości życia. Dlatego też celem prezentowanej pracy jest przedstawienie badań dotyczących oceny jakości życia oraz jej predyktorów wśród chorych neurologicznych. (PNN 2020;9(3):114–118

Einstein black holes, free scalars and AdS/CFT correspondence

We investigate AdS/CFT correspondence for two families of Einstein black holes in d > 3 dimensions, modelling the boundary CFT by a free conformal scalar field and evaluating the boundary two-point function in the bulk geodesic approximation. For the d > 3 counterpart of the nonrotating BTZ hole and for its Z_2 quotient, the boundary state is thermal in the expected sense, and its stress-energy reflects the properties of the bulk geometry and suggests a novel definition for the mass of the hole. For the generalised Schwarzschild-AdS hole with a flat horizon of topology R^{d-2}, the boundary stress-energy has a thermal form with energy density proportional to the hole ADM mass, but stress-energy corrections from compactified horizon dimensions cannot be consistently included at least for d=5.Comment: 32 pages. LaTeX with amsfonts, amsmath, amssymb. (v2: References added. v3: Geodesic horizon-crossing clarified in section 2; comparison with quasilocal energy-momentum included in section 4.

Conductance spectra of (Nb, Pb, In)/NbP -- superconductor/Weyl semimetal junctions

The possibility of inducing superconductivity in type-I Weyl semimetal through coupling its surface to a superconductor was investigated. A single crystal of NbP, grown by chemical vapor transport method, was carefully characterized by XRD, EDX, SEM, ARPES techniques and by electron transport measurements. The mobility spectrum of the carriers was determined. For the studies of interface transmission, the (001) surface of the crystal was covered by several hundred nm thick metallic layers of either Pb, or Nb, or In. DC current-voltage characteristics and AC differential conductance through the interfaces as a function of the DC bias were investigated. When the metals become superconducting, all three types of junctions show conductance increase, pointing out the Andreev reflection as a prevalent contribution to the subgap conductance. In the case of Pb-NbP and Nb-NbP junctions, the effect is satisfactorily described by modified Blonder-Tinkham-Klapwijk model. The absolute value of the conductance is much smaller than that for the bulk crystal, indicating that the transmission occurs through only a small part of the contact area. An opposite situation occurs in In-NbP junction, where the conductance at the peak reaches the bulk value indicating that almost whole contact area is transmitting and, additionally, a superconducting proximity phase is formed in the material. We interpret this as a result of indium diffusion into NbP, where the metal atoms penetrate the surface barrier and form very transparent superconductor-Weyl semimetal contact inside. However, further diffusion occurring already at room temperature leads to degradation of the effect, so it is observed only in the pristine structures. Despite of this, our observation directly demonstrates possibility of inducing superconductivity in a type-I Weyl semimetal.Comment: Accepted for Phys. Rev. B. 13 pages, 12 figures. Second version with major revisions. The title was changed. One author R. Jakiela added. New inset to Fig. 8(A). New fits in Fig. 8 (B) and Fig. 10 (B). Added figures 12 (C)-(E). Added Fig. 12 (F) with SIMS data. Rewritten chapters III-C-2 and III-C-3. Reference no. 38 removed, 11 new references: 9, 21, 22, 40-44, 46-49 were adde

Sideward flow of K+ mesons in Ru+Ru and Ni+Ni reactions near threshold

Experimental data on K+ meson and proton sideward flow measured with the FOPI detector at SIS/GSI in the reactions Ru+Ru at 1.69 AGeV and Ni+Ni at 1.93 AGeV are presented. The K+ sideward flow is found to be anti-correlated (correlated) with the one of protons at low (high) transverse momenta. When compared to the predictions of a transport model, the data favour the existence of an in-medium repulsive K+ nucleon potential.Comment: 16 pages Revtex, 3 ps-figures, submitted to Phys. Lett.

Measurement of K∗(892)0K^*(892)^0 and K0K^0 mesons in Al+Al collisions at 1.9AA GeV

New measurement of sub-threshold $K^*(892)^0$ and $K^0$ production is presented. The experimental data complete the measurement of strange particles produced in Al+Al collisions at 1.9$A$ GeV measured with the FOPI detector at SIS/GSI. The $K^*(892)^0$ / $K^0$ yield ratio is found to be $0.0315\pm 0.006 (\mathrm{stat.})\pm 0.012 (\mathrm{syst.})$ and is in good agreement with the UrQMD model prediction. These measurements provide information on in-medium cross section of $K^+$ - $\pi^-$ fusion which is the dominant process on sub-threshold $K^*(892)^0$ production.Comment: 5 pages, 4 figures, accepted for publication in Phys. Rev.

Simple model of adsorption on external surface of carbon nanotubes: a new analytical approach basing on molecular simulation data

Nitrogen adsorption on carbon nanotubes is wide- ly studied because nitrogen adsorption isotherm measurement is a standard method applied for porosity characterization. A further reason is that carbon nanotubes are potential adsorbents for separation of nitrogen from oxygen in air. The study presented here describes the results of GCMC simulations of nitrogen (three site model) adsorption on single and multi walled closed nanotubes. The results obtained are described by a new adsorption isotherm model proposed in this study. The model can be treated as the tube analogue of the GAB isotherm taking into account the lateral adsorbate-adsorbate interactions. We show that the model describes the simulated data satisfactorily. Next this new approach is applied for a description of experimental data measured on different commercially available (and characterized using HRTEM) carbon nanotubes. We show that generally a quite good fit is observed and therefore it is suggested that the observed mechanism of adsorption in the studied materials is mainly determined by adsorption on tubes separated at large distances, so the tubes behave almost independently