Suchergebnisse

The present research has been supported by the National Research Programme for 2014–2017 "Multifunctional Materials and Composites, Photonics and Nanotechnologies". ; Adsorption by graphene sponge (GS) manufactured by annealing nickel-carbon powder mixture in inert atmosphere has been studied. By determining the specific surface area (SSA) for the GS sample, it has been found that Brunauer, Emmett, Teller method (BET) of approximation of experimental isotherms gives wrong results in the pressure range of 0.025-0.12 because adsorption in this pressure region is affected by walls of ampoule. Real SSA value has been found by subtracting pore effect method (SPE) or by BET approximation in a low range of relative pressure of 0.0004-0.002. ; Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union's Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART²

The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This research commissioned by Agricultural services co-operative society 'AUGL¸ NAMS' has been conducted within framework 'The research of fruit storage technologies' funded by State program 'Competence Centre for Food in Latvia'. ; The aim of this study was to assess the effect of O3 treatment on the quality of different cultivars of apples (Malus domestica Borkh.). Apples were stored for six months at different concentrations of ozone. During the research, minor differences between ozone-treated and control fruits were found in terms of cell integrity and epicuticular wax structure. Ozone application for apple treatment could accelerate the natural ageing of the waxes found on the surface of apples, thereby reducing the thickness of the waxes. The rate of degradation for the epicuticular wax was found to be cultivar dependent. After six months of storage, the ozonation process prevented the decay of 'Iedzenu', 'Auksis' and 'Belorusskoje Malinovoje' apple cultivars, but it accelerated damage in the 'Gita' apple cultivar. A positive impact of ozone during long-term storage was found regarding flesh firmness of 'Iedzenu' apple cultivar samples subjected to O3 exposure at concentrations of 0.8 ppm and 3.0 ppm. In other cultivars of apples, significant differences between ozonation and cold storage (control) were not found. In general, ozone treatment has a potential to be applied in order to maintain the sensory quality and biologically active compound level in apples during six-month storage; however, the degree of effectiveness depends both on the cultivar and on the concentration of ozone. ; Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union's Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART²

The research has been supported by the Project ERANET RUS_ST#2017-051(Latvia) and #18-52-76002 (Russia). The Institute of Solid State Physics, University of Latvia as the Centre of Excellence has received funding from the European Union's Horizon 2020 Framework, Program H2020-WIDESPREAD-01-2016-2017-Teaming Phase 2 under grant agreement No. 739508, project CAMART2. ; Indium (0.038 at.%) and gallium (0.042 at.%) doped ZnO ceramics were prepared by hot pressing. Ceramics were investigated to determine their structural and mechanical characteristics for the prospective use in scintillators. Based on results of nanoindentation, atom force and scanning electron microscopy as well as energy dispersive X-ray spectra measurements, loca-tions of gallium within grain, indium at grain boundaries (GBs) and their different effect on the mechanical properties of ZnO ceramics were detected. Doping of gallium led to the increased modulus of elasticity in grain, decreased hardness near GBs, stabilization of micropores and brittle intercrystalline fracture mode. ZnO:In ceramic has modulus of elasticity and hardness values close to ZnO characteristics, the increased fracture toughness and some plasticity near GBs. Differences in the micromechanical properties of the ceramics correlate with the location of dopants. Results demonstrate that the ZnO:In ceramic has a greater stress relaxation potential than the ZnO:Ga. ---//---This work is licensed under a CC BY 4.0 license. ; Project ERANET RUS_ST#2017-051(Latvia) and #18-52-76002 (Russia); The Institute of Solid State Physics, University of Latvia as the Centre of Excellence has received funding from the European Union's Horizon 2020 Framework, Program H2020-WIDESPREAD-01-2016-2017-Teaming Phase 2 under grant agreement No. 739508, project CAMART2.

This research was funded by the European Regional Development Fund, grant number 1.1.1.2/VIAA/3/19/558. The Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union's Horizon 2020 Framework Programme, grant number 739508. ; Thermal etching is a widely accepted surface treatment method for studying microstructure in Na0.5Bi0.5TiO3-based compositions. Surprisingly, besides the flat pattern of grains (suitable for evaluating ceramics' microstructure), images illustrating well-expressed relief and even microstructure consisting of partly bonded cubic-shaped grains are also found among the micrographs presented in various publications. The present paper shows that this different surface character in Eu-modified Na0.5Bi0.5TiO3 can be obtained through thermal treatment across a wide range of temperatures. At higher temperatures, remarkable growth of cubic-shaped grains on the surface is observed. This growth affects the grain size distribution on the surface more than it does within the bulk of a sample. Such micrographs cannot be used to characterise the microstructure of dense ceramics. Intensive growth of TiO2 inclusions at high thermal treatment temperatures is also observed, revealing substantial evaporation of Bi and Na from the surface of a ceramic sample, but not from its core part. © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). ; European Regional Development Fund 1.1.1.2/VIAA/3/19/558; The Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union's Horizon 2020 Framework Programme, grant number 739508.