Search results for " ceramics"
showing 10 items of 117 documents
Dielectric spectra of electron-irradiated PSN ceramics
1997
The influence of electron-irradiation on the dielectric properties of transparent PSN ferroelectric ceramics is studied by low (LF) and infralow (ILF) frequency spectrum analysis. Redistribution of relaxation frequencies caused by electron-irradiation has been discovered and is related to pinning impacts of the radiation-induced defects.
Analytical stress-strain law of FRP confined masonry in compression: Literature review and design provisions
2017
Abstract The use of Fibre Reinforced Polymer (FRP) wraps has become common in practical applications to retrofit existing columns with poor structural features. Wrapping the member with one or more FRP sheets makes it possible to induce confinement action and enhance strength and ductility. This application has been widely studied and adopted in reinforced concrete members for about twenty years, while its suitability to masonry columns and piers has been investigated during the last decade. The results of several studies were summarized in different design expressions for calculating effective confinement pressure, ultimate compressive stress and strain, and the overall trend of the stress…
Finite element analysis of the out-of-plane behavior of FRP strengthened masonry panels
2017
Abstract In the present study a numerical model is proposed for the response of out-of-plane loaded calcarenite masonry walls strengthened with vertical CFRP strips applied on the substrate by means of epoxy resin. A simplified structural scheme is considered consisting in a beam fixed at one end, subjected to constant axial load and out-of-plane lateral force monotonically increasing. Two different constraint conditions are taken into account: in the first one, the panel is assumed free to rotate at the top end while, in the second one, the rotation is restrained. Three-dimensional finite elements are used for the calcarenite parts and an equivalent constitutive law available in the litera…
Synthesis of YAG nanopowder by the co-precipitation method: Influence of pH and study of the reaction mechanisms
2012
International audience; YAG nanopowders with an average grain size of 30 nm have been successfully synthesized by the co-precipitation method using nitrates with precipitant of ammonium hydrogen carbonate. The influence of precipitation conditions such as pH, aging time and calcination temperature on the formation of secondary phases has been studied. The accurate control of pH value at every stage of precipitation process is crucial to avoid the presence of YAM (Yttrium Aluminium Monoclinic, Y4Al2O9) and yttrium oxide (Y2O3) after calcination. The reaction mechanisms have been investigated using different techniques such as infrared spectroscopy, x-ray diffraction and thermal analyses. The…
Ultrafast luminescence of Ga- and In-doped ZnO ceramics
2021
The work of authors (a-c) was financially supported by Russian Foundation for Basic Research (RFBR, Russia) and the work of the last author (d) had financial support from State Education Development Agency (VIAA, Latvia) . All of that was approved as a result of ERA.Net RUS PLUS 2017 joint call for proposals. Here is the link for the joint call for reference: https://www.eranet-rus.eu/en/196.php .
Upconversion luminescence in transparent oxyfluoride glass ceramics containing hexagonal NaErF4
2019
The authors wish to express gratitude to K. Smits for TEM measurements. This research is funded by the Latvian Council of Science, project “Novel transparent nanocomposite oxyfluoride materials for optical applications”, project No. LZP-2018/1-0335. GK wishes to expresses gratitude to Arnis Riekstins "MikroTik" donation. Donations are administered by the University of Latvia Foundation. © 2019. This work is licensed under a CC BY-NC-ND 4.0 license.
Upconversion luminescence of Er3 +/Yb3 + and their role in the stabilization of cubic NaLaF4 nanocrystals in transparent oxyfluoride glass ceramics
2018
CC BY-NC-ND
Production and Properties of Lead Scandoniobate Ferroelectric Ceramics Doped with Rare-Earth Oxides
2001
Modified PbSc<sub>1/2</sub>Nb<sub>1/2</sub>O<sub>3</sub> Ferroelectric Ceramics
1997
On the Improved Current Pulse method for the thermal diffusive characterization of lithiated ceramic pebble beds
2012
Abstract Packed pebble beds are granular systems composed of small particles generally arranged in irregular lattices and surrounded by a gas filling their interstitial spaces. They show non-linear and coupled thermal and mechanical behaviours, which are under theoretical and experimental investigation to set-up a realistic constitutive model to be adopted for design-oriented purposes. At the Department of Nuclear Engineering (DIN) of the University of Palermo a realistic constitutive model of fusion-relevant pebble beds thermo-mechanical behaviour was developed adopting a “continuous” approach, based on the assumption that a pebble bed could be considered as a continuous, homogeneous and i…