Search results for "TEG"
showing 10 items of 20292 documents
Erratum to: Methods of Electron Microdiffraction and X-Ray Analysis in Structure Study of Nanodisperse Partially Stabilized ZrO2 Powders
2019
Analytical electron microscopy (AEM) has been used to study both structure and morphology of partially yttria-stabilized zirconia dioxide nanopowders (YSZ) obtained by wet-chemical methods (glycine and azeotropic distillation) and ceramics produced from them. Both morphological and structural inhomogeneity of nanopowders obtained by glycine (glc) method has been estimated. Besides the tetragonal ZrO2 phase (results of X-ray analyses) the cubic phase of ZrO2 with different degree of crystallinity has been estimated by Electron Microdiffraction (EMD) methods. In powders obtained by azeotropic distillation (dest) method besides the amorphous phase (identified in X-ray investigations) the high …
Optical detection of paramagnetic centres in activated oxyfluoride glass-ceramics
2018
Electron paramagnetic resonance (EPR), magnetic circular dichroism (MCD) and EPR detected via MCD (MCD-EPR) investigations have been performed on rare-earth activated oxyfluoride glasses and glass-ceramics. Er3+, Gd3+, and Mn2+ activators in oxyfluoride glass-ceramics show paramagnetic MCD behaviour and the MCD-EPR has been detected. The results of the MCD-EPR measurements for the Er-doped oxyfluoride glass-ceramics showed that Er3+ ions in the CaF2 crystallites in these ceramics embed only in the cubic symmetry environment, similarly to the previous observations of cubic Gd3+ centres in the glass-ceramics containing CaF2. Finally, the correlation of optics and paramagnetic centres is discu…
Determination of an empirical law of aluminium and magnesium alloys absorption coefficient during Nd :YAG laser interaction
2007
International audience; Welding laser modelling requires knowledge about relative changes of many thermo-physical parameters involved in the interaction. The absorptivity of the material is one of the most important. In this study, experimental measurements of absorptivity with an integrating sphere on two alloys (aluminium and magnesium) were made. These results were compared with an analytical calculation that takes into account the trapping of the beam by multiple reflections inside the keyhole. Based on a statistical method, an empirical law is proposed connecting absorptivity with the peak power of the laser and the duration of interaction. During the interaction, two distinct phenomen…
First principles hybrid Hartree-Fock-DFT calculations of bulk and (001) surface F centers in oxide perovskites and alkaline-earth fluorides
2020
Valuable discussions with E. A. Kotomin are gratefully acknowledged. Research contribution of R. E. and A. I. P. has been performed within the framework of the EUROfusion Enabling Research project: ENR-MFE19.ISSP-UL-02 “Advanced experimental and theoretical analysis of defect evolution and structural disordering in optical and dielectric materials for fusion applications.” The views and opinions expressed herein do not necessarily reflect those of the European Commission.
Savaime sklindančios aukštatemperatūrinės sintezės būdu gautų aliuminio oksinitrido miltelių ir jų keramikų optinės savybės
2021
The reported study was funded by RFBR according to the Research Project No. 19-08-00655. V.P. acknowledges the State Research Program ‘Aug-stas enerģijas fizika un paātrinātāju tehnoloģijas’ (Projekta Nr. VPP-IZM-CERN-2020/1-0002). The Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the H2020-WIDESPREAD-01-2016-2017-Teaming Phase2 under Grant Agreement No. 739508, Project CAMART2.
Enduring Sacred Places: The Astronomical Orientation of the Iberian Cave-Sanctuary of Cueva Santa del Cabriel in Spain
2019
This paper presents the results of an archaeoastronomical study of the Iberian Iron Age cave-sanctuary of Cueva Santa del Cabriel, near the town of Mira in the province of Cuenca, Castilla-La Mancha, central Spain, together with a review of the latest archaeological and ethnographical data about the site. We found that the cave's 12 m-long access corridor is oriented precisely along the summer solstice sunset, so that the north wall of the main gallery is partially illuminated by sunlight at this time. Although the cave was in use from the Late Chalcolithic, it became an important religious centre in the Iberian period. After an apparent hiatus during the Roman and Islamic occupations, its …
Design and analysis of non-linear circuit with tunnel diode for hybrid control systems
2018
Electric circuits with tunnel diode's represent a classical example of dynamic systems with nonlinearities, which feature piecewise negative damping and multiple equilibria and, as consequence, nontrivial trajectories in the state-space. In this paper, we describe the experimental design and analysis of an electrical circuit, including a tunnel diode, allowing for a storage behavior with bistable output voltage states - low and high. The system is modeled for simulation and an experimental setup is designed and implemented in order to run a formal verification on different tools, applying a variety of hybrid control methods. The nonlinear diode's characteristic curve is experimentally deter…
Custom measurement system for memristor characterisation
2021
Abstract A cheap, compact and customisable characterisation system for memristor devices, working between ± 10 V, is presented. SPICE (Simulation Program with Integrated Circuit Emphasis) simulations are performed to verify the circuit feasibility and a proper software is developed to drive the system. The potentiality of the realised system is tested by performing several electrical measurements on both Cu/HfO2/Pt memristors and two-terminals commercial devices.
Structure and dielectric properties of Na0.5Bi0.5TiO3-CaTiO3 solid solutions
2016
Despite wide studies of Na0.5Bi0.5TiO3, structure of this material and its connection with the observed physical properties still raise numerous questions due to mutually contradicting results obtained. Here, structure and dielectric properties of poled and unpoled Na0.5Bi0.5TiO3-CaTiO3 solid solutions are studied, projecting the obtained concentration dependence of structure and dielectric properties on pure Na0.5Bi0.5TiO3 as the end member of this material group. X-ray diffraction patterns for Na0.5Bi0.5TiO3-CaTiO3 solid solutions reveal dominating of an orthorhombic Pnma phase, even for the compositions approaching the end composition (Na0.5Bi0.5TiO3), whereas structure of pure Na0.5Bi0.…
From EFTA to EC/EU and Back to EFTA? The European Economic Area (EEA) As a Possible Scenario for the UK-EU Relations After Brexit
2018
Brexit is announced to take place and it appears, that the most probable scenario for the UK is the “Norway-Option”, i.e., to (again) become a member of the European Free Trade Association (EFTA) and join the EEA. The chapter identifies the major claims of the leave-campaign to analyse, whether by doing so, the Brexit proponents will achieve what they campaigned for. Furthermore, the paper explains the functioning of the EEA, exploring the potential changes for the UK, the EU, and the EEA/EFTA.