Ytterbium
Mostrando 1-12 de 17 artigos, teses e dissertações.
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1. JUDD-OFELT ANALYSIS OF Tb3+ AND UPCONVERSION STUDY IN Yb3+-Tb3+ CO-DOPED CALIBO GLASSES
We report on the study of the spectroscopic properties in Ytterbium-Terbium (Yb3+-Tb3+) co-doped calcium lithium borate (CaLiBO) glasses, with the study’s focus being on the upconversion process. Intensity parameters Ωλ for CaLiBO:Tb3+ are determined by the Judd-Ofelt method to be Ω2 = 15.5 × 10-20 cm2, Ω4 = 1.90 × 10-20 cm2 and Ω6 = 3.69 × 10-20 c
Quím. Nova. Publicado em: 2020-02
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2. Microstructure and Dielectric Behavior of Ytterbium Doped BaZr0.1Ti0.9O3 Ceramics
BaZr0.1Ti0.9O3 ceramics of perovskite structure are prepared by solid state reaction method with addition of x Yb2O3 (x= 0.0, 0.1, 0.3, 0.5 and 0.7 mol%), respectively, and their dielectric properties are investigated. Room temperature X-ray diffraction study suggested that the compositions have a single phase with a perovskite structure. A small decrease in
Mat. Res.. Publicado em: 10/10/2016
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3. Properties of SiC Ceramics Sintered via Liquid Phase Using Al2O3 + Y2O3, Al2O3 + Yb2O3 and Al2O3 + Dy2O3 as Additives: a Comparative Study
Silicon carbide (SiC) ceramics show excellent performance at high temperatures. Due to the high covalence of Si-C bonds, these ceramics are produced successfully only via liquid phase sintering (LPS). In this work, SiC ceramics were sintered via LPS using eutectic mixtures of Al2O3+Y2O3, which served as a standard for comparison, Al2O3+Yb2O3 and Al2O3+Dy2O3.
Mat. Res.. Publicado em: 2015-06
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4. Influence of radiopaque fillers on physicochemical properties of a model epoxy resin-based root canal sealer
Objective: To verify the influence of radiopaque fillers on an epoxy resin-based sealer. Material and Methods: Experimental sealers were formulated by adding 20%, 40%, 60%, 80%, 100% and 120% of calcium tungstate, ytterbium trifluoride or barium sulphate by weight to an epoxy-resin-base. Setting time, flow, film thickness, radiopacity, sorption, solubi
J. Appl. Oral Sci.. Publicado em: 2013-12
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5. Occurrence of Defects in Laser Beam Welded Al-Cu-Li Sheets with T-Joint Configuration
Abstract: In the aerospace industry, laser beam welding has been considered as one of the most promising routes among the new manufacturing processes. Substitution of riveting by laser beam welding of aircraft structures has contributed to weight and cost savings. Concurrently, new aluminum alloys have been developed with the addition of lithium with better
J. Aerosp. Technol. Manag.. Publicado em: 2012-12
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6. Produção e caracterização de vidros de telureto tridopados com íons de terras raras e nanopartículas metálicas para uso em displays coloridos. / Production and characterization of tellurite glasses doped with rare earth ions and metallic nanoparticles for use in color displays.
This works presents studies of the production and the characterization of TeO2 -PbO-GeO2 doped with erbium, thulium and ytterbium ions and also prepared with different metallic nanoparticles for applications in displays. This glass system presents a broad transmission window in the visible and infrared (350 - 6500 nm), high solubility for rare earth ions, lo
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 08/04/2011
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7. Desenvolvimento de técnica para nucleação de nanopartículas metálicas em vidros de germanato dopados com íons de túlio para aplicações em dispositivos fotônicos. / Development of metalic nanoparticles nucleation technique in thulium doped germanate glasses for applications in photonic devices.
Neste trabalho são apresentadas a preparação, a metodologia adotada para a nucleação de nanopartículas (NPs) de prata e a investigação das propriedades luminescentes do sistema vítreo GeO2-PbO dopado com íons de túlio e codopado com íons de túlio e itérbio, na presença de NPs de prata, visando aplicação em dispositivos fotônicos. Este siste
Publicado em: 2010
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8. Ressonancia de spin eletronico (ERS) em compostos tipo fermions pesadas a base de Iterbio (Yb) / Electron spin resonance (ERS) in Ytterbium (Yb) based heavy fermion compounds
Nesta Dissertação desenvolvemos estudos de Ressonância de Spin Eletrônico (ESR) em monocristais dos compostos tipo férmions pesados YbR h2Si2 e YbAlB4. No caso do sistem YbRh2Si2, exploraramos os experimentos de ESR para três bandas de frequência existentes em nosso laboratório (n = 4,1 GHz (Banda-S), n = 9,4 GHz (Banda-X) e n = 34,0 GHz (Banda-Q)),
Publicado em: 2009
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9. Bioactive compounds from Brazilian strawberry cultivars (Fragaria x ananassa Duch.): Characterization and bioavailability of ellagic acid derivatives / Compostos bioativos de cultivares brasileiras de morango (Fragaria x ananassa Duch.): caracterização e estudo da biodisponibilidade dos derivados de ácido elágico
Strawberries are a good source of vitamin C, flavonoids and ellagic acid derivatives and are consumed in Brazil in large quantities. The objectives of the present work were: characterization of different cultivars with respect to the content of bioactive compounds, optimization of the method for quantification of total ellagic acid content, purification and
Publicado em: 2008
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10. Study of the viability of the production of lutetium 177 in the Nuclear Reactor IEA-R1 at IPEN/CNEN-SP / Estudo da viabilidade de produção do Lutécio-177 no Reator Nuclear IEA-R1 do IPEN/CNEN-SP
The - emitter 177 Lu is a promising therapeutic radioisotope for the curative treatment of cancer using labelled proteins. It has a half life of 6.71 day and maximum and average - energies of 421 and 133 keV, respectively, resulting in a short range of irradiation of tissue. The decay is accompanied by the emission of low energy -radiation of 208.3 keV (11%)
Publicado em: 2008
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11. Propriedades ópticas de vidros teluretos dopados com íons terras-raras e nanopartículas de ouro
In this work we will accomplish the optical characterization of host vitreous, doped with rare-earth ions and nanoparticles of gold, with several compositions, but maintaining as main element the tellurium. Those stencil they are known in the literature as tellurite glasses. We will treat of two groups of samples, in the first we have glasses teluretos with
Publicado em: 2007
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12. Effect of surface deposited rare earth oxide gel characteristics on cyclic oxidation behavior of Fe20-Cr alloys
Rare earths have been used to increase high temperature oxidation resistance of many chromium dioxide and alumina forming alloys. These rare earths can be added as elements (or as oxide dispersions) to the alloys or applied as an oxide coating to the alloy surface. The sol-gel technique is considered to be very efficient to apply fine oxide particle coatings
Materials Research. Publicado em: 2006-06