Effect of hydration on conductivity of Ba4La x Ca2-X Nb2O11 + 0.5x (x = 0.5, 1, 1.5, 2) phases

Substitution of Ca by La in initial cubic double perovskite Ba 4(Ca2Nb2)O11[VO]1 allowed obtaining phases with a similar structure with a lower content of structural oxygen vacancies, Ba4(La x Ca2-x Nb 2)O11 + 0.5x [VO]1-0.5x (x = 0.5, 1, 1.5, 2). The impedance technique was used to measure the temperature dependences of conductivity in the atmosphere of dry and humid air. Transport numbers determined using the EMF method in an oxygen-air and water steam concentration cells point to the predominantly hole nature of conductivity in the high-temperature region (T > 600 C) and to predominance of proton conductivity in the low-temperature region. Activation energies of hole and proton conductivity were calculated. Thermogravimetric measurements were carried out under heating from 25 to 1000 C with simultaneous mass-spectrometric determination of evolved H2O and CO2. The properties of the studied Ba4(La x Ca2-x Nb 2)O11 + 0.5x (x = 0.5, 1, 1.5, 2) phases were compared with the earlier studied Ba4-x La x (Ca2Nb 2)O11 + 0.5x phases with similar lanthanum content. © 2013 Pleiades Publishing, Ltd

Novel Nb5+-doped hexagonal perovskite Ba5In2Al2ZrO13 (structure, hydration, electrical conductivity)

The new phase Ba5In2Al2Zr0.9Nb0.1O13.05 with hexagonal perovskite structure was obtained. The substitution of Zr4+ by smaller Nb5+ was accompanied by the incorporation of the oxygen interstitials and did not lead to a significant change in the lattice parameters. It was established that the investigated sample was capable for water incorporation from the gas phase, the hydration degree value was 0.24 mol H2O. IR-spectroscopy analysis defined the presence of OH−-groups with different thermal stability, which participate in different hydrogen bonds. The new phase Ba5In2Al2Zr0.9Nb0.1O13.05 demonstrates the predominant protonic conductivity at pH2O = 2·10−2 atm and Т600 °C

Proton and Oxygen-Ion Conductivities of Hexagonal Perovskite Ba5In2Al2ZrO13

The hexagonal perovskite Ba5 In2Al2ZrO13 and In3+-doped phase Ba5 In2.1Al2Zr0.9O12.95 were prepared by the solid-state synthesis method. The introduction of indium in the Zr-sublattice was accompanied by an increase in the unit cell parameters: a = 5.967 Å, c = 24.006 Å vs. a = 5.970 Å, c = 24.011 Å for doped phase (space group of P63 /mmc). Both phases were capable of incorporating water from the gas phase. The ability of water incorporation was due to the presence of oxygen deficient blocks in the structure, and due to the introduction of oxygen vacancies during doping. According to thermogravimetric (TG) measurements the compositions of the hydrated samples corresponded to Ba5 In2Al2ZrO12.7 (OH)0.6 and Ba5 In2.1Al2Zr0.9O12.54 (OH)0.82. The presence of different types of OH−-groups in the structure, which participate in different hydrogen bonds, was confirmed by infrared (IR) investigations. The measurements of bulk conductivity by the impedance spectroscopy method showed that In3+-doping led to an increase in conductivity by 0.5 order of magnitude in wet air (pH2O = 1.92·10−2 atm); in this case, the activation energies decreased from 0.27 to 0.19 eV. The conductivity−pO2 measurements showed that both the phases were dominant proton conductors at T < 500◦C in wet conditions. The composition Ba5 In2.1Al2Zr0.9O12.95 exhibited a proton conductivity ~10−4 S·cm−1 at 500◦C. The analysis of partial (O2−, H+, h•) conductivities of the investigated phases has been carried out. Both phases in dry air (pH2O = 3.5·10−5 atm) showed a mixed (oxygen-ion and hole) type of conductivity. The obtained results indicated that the investigated phases of Ba5 In2Al2ZrO13 and Ba5 In2.1Al2Zr0.9O12.95 might be promising proton-conducting oxides in the future applications in electrochemical devices, such as solid oxide fuel cells. Further modification of the composition and search for the optimal dopant concentrations can improve the H+-conductivity. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.Russian Science Foundation, RSF: 22-23-20003Funding: This research was supported by the Russian Science Foundation and Government of Sverdlovsk region, Joint Grant 22-23-20003 https://rscf.ru/en/project/22-23-20003/

SWATH-MS dataset of heat-shock treated Drosophila melanogaster embryos

Data independent acquisition (DIA) has emerged as a promising mass spectrometry based approach, combining the advantages of shotgun and targeted proteomics. Here we applied a DIA approach (termed SWATH) to monitor the dynamics of the Drosophila melanogaster embryonic proteome upon heat-shock treatment. Embryos were incubated for 0.5, 1 or 3 h at 37 °C to induce heat-shock or maintained at 25 °C. The present dataset contains SWATH files acquired on a Sciex Triple-TOF 6600. A spectral library built in-house was used to analyse these data and led to the quantification of more than 2500 proteins at every timepoint. The files presented here are permanent digital maps and can be reanalysed to search for new questions. The data have been deposited with the ProteomeXchange Consortium with the dataset identifier PRIDE: PXD004753.B.F, D.K and D.J.H.N are funded by BBSRC, United Kingdom (Ref: BB/L002817/1)

Interaction between LiH molecule and Li atom from state-of-the-art electronic structure calculations

State-of-the-art ab initio techniques have been applied to compute the potential energy surface for the lithium atom interacting with the lithium hydride molecule in the Born–Oppenheimer approximation. The interaction potential was obtained using a combination of the explicitly correlated unrestricted coupled-cluster method with single, double, and noniterative triple excitations [UCCSD(T)-F12] for the core–core and core–valence correlation and full configuration interaction for the valence–valence correlation. The potential energy surface has a global minimum 8743 cm−1 deep if the Li–H bond length is held fixed at the monomer equilibrium distance or 8825 cm−1 deep if it is allowed to vary. In order to evaluate the performance of the conventional CCSD(T) approach, calculations were carried out using correlation-consistent polarized valence X-tuple-zeta basis sets, with X ranging from 2 to 5, and a very large set of bond functions. Using simple two-point extrapolations based on the single-power laws X−2 and X−3 for the orbital basis sets, we were able to reproduce the CCSD(T)–F12 results for the characteristic points of the potential with an error of 0.49% at worst. The contribution beyond the CCSD(T)–F12 model, obtained from full configuration interaction calculations for the valence–valence correlation, was shown to be very small, and the error bars on the potential were estimated. At linear LiH–Li geometries, the ground-state potential shows an avoided crossing with an ion-pair potential. The energy difference between the ground-state and excited-state potentials at the avoided crossing is only 94 cm−1. Using both adiabatic and diabatic pictures, we analyze the interaction between the two potential energy surfaces and its possible impact on the collisional dynamics. When the Li–H bond is allowed to vary, a seam of conical intersections appears at C2v geometries. At the linear LiH–Li geometry, the conical intersection is at a Li–H distance which is only slightly larger than the monomer equilibrium distance, but for nonlinear geometries it quickly shifts to Li–H distances that are well outside the classical turning points of the ground-state potential of LiH. This suggests that the conical intersection will have little impact on the dynamics of Li–LiH collisions at ultralow temperatures. Finally, the reaction channels for the exchange and insertion reactions are also analyzed and found to be unimportant for the dynamics

The Debye-Waller Factor in solid 3He and 4He

The Debye-Waller factor and the mean-squared displacement from lattice sites for solid 3He and 4He were calculated with Path Integral Monte Carlo at temperatures between 5 K and 35 K, and densities between 38 nm^(-3) and 67 nm^(-3). It was found that the mean-squared displacement exhibits finite-size scaling consistent with a crossover between the quantum and classical limits of N^(-2/3) and N^(-1/3), respectively. The temperature dependence appears to be T^3, different than expected from harmonic theory. An anisotropic k^4 term was also observed in the Debye-Waller factor, indicating the presence of non-Gaussian corrections to the density distribution around lattice sites. Our results, extrapolated to the thermodynamic limit, agree well with recent values from scattering experiments.Comment: 5 figure

Protonic Transport in Layered Perovskites BaLanInnO3n+1 (n = 1, 2) with Ruddlesden-Popper Structure

The work focused on the layered perovskite-related materials as the potential electrolytic components of such devices as proton conducting solid oxide fuel cells for the area of clean energy. The two-layered perovskite BaLa2 In2O7 with the Ruddlesden–Popper structure was investigated as a protonic conductor for the first time. The role of increasing the amount of perovskite blocks in the layered structure on the ionic transport was investigated. It was shown that layered perovskites BaLanInnO3n+1 (n = 1, 2) demonstrate nearly pure protonic conductivity below 350◦C. © 2022 by the authors. Licensee MDPI, Basel, Switzerland

Ocular involvement of sars-cov-2 in a polish cohort of covid-19-positive patients

The coronavirus SARS-CoV-2 responsible for the current human COVID-19 pandemic has shown tropism toward different organs with variable efficiency, eyes included. The purpose of this study has been to investigate the presence of detectable SARS-CoV-2 infection in ocular swabs in patients affected by COVID-19. A consecutive series of 74 COVID-19-positive patients (age 21–89) were enrolled at two Polish COVID-19 hospitals for 4 months and were characterized by PCR for the presence of the SARS-CoV-2 genetic material in nasopharyngeal (NP) and ocular swabs, while their respiratory and ocular symptoms were noted. Almost 50% of them presented with severe/crit-ical respiratory involvement, and some degree of eye disease. No tight correlation was observed between the presence of ocular and respiratory symptoms. Three male patients presenting with severe/critical lung disease tested positive in ocular swab, however with mild/moderate ocular symptoms. In conclusion, our study lends further support to the view that overt ocular infection by the SARS-CoV-2 virus is not such a frequent occurrence

HYDRATION AND ELECTROCONDUCTIVITY OF THE DOPED BaLA2In2O7

Phases BaLa2In2O7 and Ti-, Zr-, Nb-substituted solid solutions was synthesized by solid state route as potential protonic conductors. Hydration of BaLa2In2O7 was measured by ther-mogravimetry in wet nitrogen atmosphere under heating and cooling. The degree of hydration for BaLa2In2O7 rise to 0,2

DEVELOPMENT OF SYNTHESIS METHODS AND INVESTIGATION OF PROPERTIES OF PEROVSKITES BASED ON CeAlO3

This article is devoted to the development of the solid state and solution combustion synthesis method and investigation of the properties of perovskite compounds based on CeAlO3. Structure, phase stability, conductivity and thermal expansion have been investigated