Single Crystal Fibers
Mostrando 1-9 de 9 artigos, teses e dissertações.
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1. Fibras monocristalinas de tungstatos duplos de metais alcalinos e terras raras: um estudo de crescimento através da técnica de micro-pulling-down / ALKALI RARE EARTH DOUBLE TUNGSTATES SINGLE CRYSTAL FIBERS: A GROWTH STUDY BY THE MICRO-PULLING DOWN METHOD
Neste trabalho, foram realizadas sínteses dos tungstatos duplos NaLa(WO4)2 (NLW), NaGd(WO4)2 (NGW) e LiLa(WO4)2 (LLW) puros e simplesmente dopados com os íons Nd3+ e Yb3+; comparando-se dois métodos de obteção: o de reação no estado sólido e o sol-gel modificado (Pechini). Verificou-se que o envelhecimento do reagente La2O3 (adsorção de umidade amb
Publicado em: 2009
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2. Crescimento de fibras de LiYF4 dopadas com Nd3+ e Er3+ para aplicações em lasers de estado sólido / SINGLE FIBER CRYSTAL GROWTH OF Nd3+ AND Er3+- DOPED LiYF4 FOR SOLID STATE LASER APPLICATIONS
In the present work, we studied the growth of single crystal fibers of LiYF4 (YLF) doped with Er3+ or Nd3+ by the resistive micro-pulling-down (-PD) tecnhique. A new method for crucible preparation was developed to improve the growth process. The use of better-built crucibles allows their use in more than one experiment, increasing the process reproducibilit
Publicado em: 2008
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3. CRESCIMENTO E CARACTERIZAÇÃO DE FIBRAS MONOCRISTALINAS DE FLUORETOS DO TIPO LiY1-xTRxF4 (TR = TERRAS-RARAS) / GROWTH AND CHARACTERIZATION OF FLUORIDE CRYSTALLINE FIBRES TYPE LiY1-xTRxF4 (RE = RARE-EARTH)
In this work we present the growth and characterization of LiF and pure and rare-earth doped (Er and Nd) yttrium-lithium tetra-fluoride (LiYF4 or YLF) by the micro-pulling-down technique (µ-PD). The use of this technique is original for the present purpose. A m-PD prototype in the resistive mode was firstly built to understand the most important operational
Publicado em: 2005
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4. Caracterização espectroscópica de possíveis meios ativos para lasers de Nd3+ e Tm3+ / Spectroscopic characterization of possible Nd3+ and Tm3+ laser active media
In this work we have made an important contribution to the growing research of new laser materials that can be pumped by low cost diode lasers or by the Upconversion process to operate in the near-infrared and visible spectral regions. Three kinds of hosts, doped with the rare earth ions (Nd3+ and Tm3+) were studied, and they present potential characteristic
Publicado em: 2003
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5. Study of optical properties of crystalline fibers of CVO:nd3+ and CMO: nd3+/nb5+ / Estudo das propriedades ópticas de fibras cristalinas de CVO:Nd3+ e CMO:Nd3+/Nb5
The present work release an extensive study of spectroscopic properties on CMO:NdNbO4 and CVO:Nd3+ single crystal fibers, in searching for new laser materials activated with diode laser. The fibers were grown by LHPG (laser Heated Pedestal Growth) technique that permits a fast production of fibers with appropriate dimension for mini laser construction, witho
Publicado em: 2003
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6. Growth of single crystal fibers by the technique LHPG and characterization of compounds Ba0,77Ca0,23TiO3, Ca2FeMoO6, CaMoO4 and SrMoO4-CaMoO4 (crystal gradient). / Crescimento de fibras monocristalinas pela técnica LHPG e caracterização dos compostos Ba0,77Ca0,23TiO3, Ca2FeMoO6, CaMoO4 e SrMoO4-CaMoO4 (cristal gradiente).
Este trabalho teve como finalidade determinar e otimizar as condições para a preparação e a caracterização de monocristais de alguns óxidos que apresentam considerável dependência de suas propriedades físico-químicas finais e magnitude da pressão da atmosfera de crescimento. Experimentos que envolvem diversas adaptações de um sistema de fusão
Publicado em: 2003
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7. Preparação e caracterização de fibras monocristalinas de SrTiO3, SrTi(1-X)RuXO3 e de Sr2RuO4. / Preparation and characterization of SrTiO3, SrTi(1-X) RuXO3 and Sr2RuO4 single crystal fibers.
Neste trabalho desenvolvemos processos de crescimento e caracterização de fibras monocristalinas de SrTiO3 e Sr2RuO4 puros e como soluções sólidas através da técnica LHPG (laser heated pedestal growth). Esses processos são descritos desde as sínteses dos compostos, preparação dos nutrientes e sementes necessários para aplicação da técnica. Alg
Publicado em: 1996
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8. X-ray diffraction studies of fibers and crystals of deoxygenated sickle cell hemoglobin.
Paracrystalline fibers of deoxygenated sickle hemoglobin in erythrocytes or concentrated solutions exhibit a phase transformation to a fully crystalline state. X-ray diffraction patterns of the fiber and crystallites are similar except in two respects: the equatorial spacings of the fibers suggest that they pack into a square lattice with a = 220 A, whereas
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9. Polarization of fluorescently labeled myosin subfragment-1 fully or partially decorating muscle fibers and myofibrils.
Fluorescently labeled myosin heads (S1) were added to muscle fibers and myofibrils at various concentrations. The orientation of the absorption dipole of the dye with respect to the axis of F-actin was calculated from polarization of fluorescence which was measured by a novel method from video images of muscle. In this method light emitted from muscle was sp