Search results for " ceramic"

showing 10 items of 228 documents

Investigation of absorber and heterojunction in the pure sulphide kesterite

2021

This paper aims to study the properties of the absorber layer and the heterojunction in kesterite solar cells. The Cu2ZnSnS4 (CZTS) thin films were layered on a glass substrate from a colloidal solution of metal salts and thiourea dissolved in a mixture of water and ethanol and deposited by spin coating technique. The samples were then heat treated in a furnace, in the presence of sulphur powder and under a nitrogen gas flow. The results revealed the formation of homogeneous layers of a pure kesterite phase of CZTS crystallites after heat treatment with correct stoichiometry and oxidation states. The optical transmission measurements indicate an energy band-gap of 1.4 eV and an absorption c…

Materials scienceClay industries. Ceramics. Glass02 engineering and technologySubstrate (electronics)engineering.material7. Clean energyCZTSIndustrial and Manufacturing Engineering[SPI.MAT]Engineering Sciences [physics]/MaterialsAlineación de bandaschemistry.chemical_compoundPelículas delgadasCZTSKesteriteThin filmKesteritaSpin coating020502 materialsHeterojunctionHeterojunciónTP785-8690205 materials engineeringchemistryChemical engineeringMechanics of MaterialsCeramics and CompositesengineeringCrystalliteLayer (electronics)
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Mechanical behavior of polylactic acid/polycaprolactone porous layered functional composites

2016

Abstract Biopolymeric porous devices exhibiting graded properties can play a crucial role in several fields, such as tissue engineering or controlled drugs release. In this context, the gradient of a specific property can be achieved by developing porous laminates composed by different types of materials. This work presents for the first time a multi-phasic porous laminate based on polycaprolactone (PCL) and polylactic acid (PLA) prepared by combining melt mixing, compression molding and particle leaching. All the materials were characterized from a morphological and a mechanical point of view. The results put into evidence the possibility to tune and to predict the mechanical properties by…

Materials scienceCompression moldingCompression moldingFunctionally graded materialCeramics and Composite02 engineering and technology010402 general chemistry01 natural sciencesControlled drugsIndustrial and Manufacturing Engineeringchemistry.chemical_compoundLayered structurePolylactic acidTissue engineeringAdhesion; Compression molding; Functionally graded materials; Layered structures; Mechanical properties; Ceramics and Composites; Mechanics of Materials; Industrial and Manufacturing Engineering; Mechanical EngineeringMechanics of MaterialComposite materialPorosityMelt mixingMechanical Engineering021001 nanoscience & nanotechnology0104 chemical scienceschemistryMechanics of MaterialsPolycaprolactoneCeramics and CompositesAdhesionLeaching (metallurgy)0210 nano-technologyMechanical propertie
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ELECTRICAL PROPERTIES OF LEAD FERROTANTALATE CERAMICS

2009

ABSTRACT Perovskite structures with high dielectric constants and magnetic properties play an important role in micro- and optoelectronics and have numerous practical applications. Relaxor type ferroelectric ceramics PbFe1/2Ta1/2O3 with perovskite structure was subject of present studies. Pyrochlore free lead ferrotantalate ceramics were produced by solid state technology from oxides. Low- and infra-low frequency studies of dielectric properties of PbFe1/2Ta1/2O3 ceramics have revealed considerable infra-low frequency dispersion at temperatures above the temperature of maximum dielectric permittivity. The observed dispersion described by lemniscates is due to a considerable Maxwell-Wagner r…

Materials scienceCondensed matter physicsFerroelectric ceramicsRelaxation (NMR)PyrochloreFerroicsDielectricengineering.materialCondensed Matter PhysicsElectronic Optical and Magnetic MaterialsControl and Systems Engineeringvisual_artDispersion (optics)Materials ChemistryCeramics and Compositesengineeringvisual_art.visual_art_mediumCeramicElectrical and Electronic EngineeringPerovskite (structure)Integrated Ferroelectrics
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Features of Phase Diagrams of Binary Pb(B<sub>1/2</sub>Nb<sub>1/2</sub>)O<sub>3</sub>-PbTiO<sub>3</sub&g…

2001

Materials scienceCondensed matter physicsMechanics of MaterialsMechanical EngineeringPhase (matter)Ferroelectric ceramicsBinary numberGeneral Materials ScienceCoercivityPhase diagramKey Engineering Materials
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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.

Materials scienceCondensed matter physicsSolid-state physicsFerroelectric ceramicschemistry.chemical_elementDielectricElectronElectroluminescenceThuliumNuclear magnetic resonancechemistryvisual_artvisual_art.visual_art_mediumIrradiationCeramicSPIE Proceedings
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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…

Materials scienceConstitutive equation0211 other engineering and technologiesCeramics and Composite02 engineering and technologyIndustrial and Manufacturing EngineeringRetrofit021105 building & constructionMechanics of MaterialComposite materialDuctilityCompression; FRP confinement; Masonry; Retrofit; Ceramics and Composites; Mechanics of Materials; Mechanical Engineering; Industrial and Manufacturing EngineeringMasonrybusiness.industryMechanical EngineeringStress–strain curveCompressionStructural engineeringFibre-reinforced plasticMasonry021001 nanoscience & nanotechnologyCompression (physics)Strength of materialsSettore ICAR/09 - Tecnica Delle CostruzioniCompressive strengthMechanics of MaterialsCeramics and CompositesFRP confinement0210 nano-technologybusiness
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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…

Materials scienceConstitutive equationShell (structure)FRP-masonry interfaceCeramics and CompositeFinite element modeling; FRP strengthening; FRP-masonry interface; Masonry panels; Out-of-plane behavior; Ceramics and Composites; Mechanics of Materials; Mechanical Engineering; Industrial and Manufacturing Engineering02 engineering and technology010402 general chemistry01 natural sciencesIndustrial and Manufacturing EngineeringFRP strengtheningMechanics of MaterialMasonry panelsComposite materialFinite element modelingMasonry panelbusiness.industryMechanical EngineeringLinear elasticityStructural engineeringMasonryFibre-reinforced plastic021001 nanoscience & nanotechnologyStrength of materialsFinite element method0104 chemical sciencesSettore ICAR/09 - Tecnica Delle CostruzioniMechanics of MaterialsCeramics and Composites0210 nano-technologybusinessBeam (structure)Out-of-plane behavior
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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…

Materials scienceCoprecipitationInorganic chemistryOxideTRANSPARENT CERAMICSFABRICATIONchemistry.chemical_element02 engineering and technology01 natural scienceslaw.inventionInorganic Chemistrychemistry.chemical_compoundlawAluminiumYTTRIUM-ALUMINUM-GARNET0103 physical sciencesMaterials ChemistryNANO-SIZED POWDERCalcinationPhysical and Theoretical ChemistryPerovskite (structure)010302 applied physicsPRECURSORSPrecipitation (chemistry)Yttrium021001 nanoscience & nanotechnologyCondensed Matter PhysicsElectronic Optical and Magnetic MaterialschemistryChemical engineeringPRECIPITATIONCeramics and CompositesLASER0210 nano-technologyMonoclinic crystal system
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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 .

Materials scienceGeneral Computer Science01 natural sciences010309 opticsScintillating ceramics0103 physical sciencesNano-Zinc oxideApplied optics. PhotonicsCeramicElectrical and Electronic Engineering010302 applied physicsQuenchingDopantPrecipitation (chemistry)Near-band-edge emission4. EducationDopingQC350-467Optics. LightAtomic and Molecular Physics and OpticsElectronic Optical and Magnetic MaterialsTA1501-1820Chemical engineeringvisual_artRadioluminescencevisual_art.visual_art_medium:NATURAL SCIENCES [Research Subject Categories]Grain boundaryLuminescenceTotal transmittance
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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.

Materials scienceGlass ceramicsAnalytical chemistry02 engineering and technology010402 general chemistry01 natural sciences7. Clean energyIonMaterials Chemistry:NATURAL SCIENCES:Physics [Research Subject Categories]CeramicSpectroscopyOxyfluorideSite-selective spectroscopyMechanical EngineeringMetals and AlloysRate equation021001 nanoscience & nanotechnologyPhoton upconversion0104 chemical sciencesMicrocrystallineNanocrystalMechanics of MaterialsTransmission electron microscopyvisual_artvisual_art.visual_art_medium0210 nano-technologyNaErF4Upconversion
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