Laser Plasma Interaction
Mostrando 1-12 de 16 artigos, teses e dissertações.
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1. Additive Techniques to Refurbish Ni Based Components
Abstract The attractiveness of additive techniques to refurbish worn components requires the availability of data from different process. This study correlates two additive techniques, Plasma Transferred Arc (PTA – AM) and Direct Laser Deposition (DLD), using IN 625 wire. Specific features of each technique are discussed regarding their potential use to re
Soldag. insp.. Publicado em: 09/05/2019
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2. Effect of a cordless retraction paste on titanium surface: a topographic, chemical and biocompatibility evaluation
Good exposure of the preparation margins and haemostasis in the sulcular gingiva are necessary for accurate impressions to produce precise restorations. The use of cordless retraction paste material in implant dentistry is a relatively novel application. However, few studies have been conducted on the use of retraction pastes and their possible interaction w
Braz. oral res.. Publicado em: 2013-06
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3. Investigação Experimental da Adição de Energia por Laser em Escoamento Hipersônico de Baixa Densidade
The possibility of reducing the aerodynamic drag and heating of a hypersonic vehicle by addition energy to the air ahead of it is an attractive idea directed toward the hypersonic field. (Mach>5) and can be realized by laser induced plasma generation. In this context, this work presents original results in the experimental investigation of the energy addi
Publicado em: 2008
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4. Analysis of time-resolved laser plasma ablation using an imaging spectra technique
Pulsed laser deposition (PLD) is extensively employed for the growth of thin films. The laser-material interaction involves complex processes of heating, melting, vaporization, ejection of atoms, ions and molecules, shock waves, plasma initiation, expansion and deposition onto a substrate. The understanding of the spatial and temporal distribution of a plasm
Brazilian Journal of Physics. Publicado em: 2007-12
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5. Construction and evaluation of a laser induced breakdown spectroscopy instrument: application in alloy samples / Construção e avaliação de um instrumento para espectroscopia de emissão em plasma induzido por laser (LIBS) : aplicação em ligas metalicas
In this work a time resolved LIBS instrument (TRELIBS) was built and its performance evaluated in qualitative and quantitative analysis. Additionally, exploratory studies are presented on the influence of parameters that affect the LIBS analysis. The instrument was built employing optical systems and devices of modern technology: an ICCD device, an echelle p
Publicado em: 2007
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6. Avaliação do efeito da indução de polimerização com diferentes fontes de luz e dos meios de envelhecimento sobre a microdureza de cilindros de resina composta / Evaluation of the induction of polymerization effect with different light sources and aging procedures on resin composite microhardness
The aim of this study was to evaluate the effect of the light-curing devices (Halogen/HAL, Light Emitting Diodes/LED, Argon Laser/LAS and Plasma Arc/PAC) and aging procedures on the microhardness of bottom and top surfaces of resin composite cylinders with 4mm height, submitted to thermal and mechanical cycles, and one year storage. For this study 200 specim
Publicado em: 2007
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7. Laser production of highly charged ions
A summary of ion generation experiments at both low (10(9) W=cm²) and high (10(16) W=cm²) laser intensities, using Nd:YAG and iodine lasers, as well as the properties of the ions produced, are presented. Different medium- and high-Z elements were tested as a target: Ag, Al, Au, Co, Cu, Nb, Ni, Pb, Pt, Sn, Ta, W. A maximum charge state 55+ and maximum energ
Brazilian Journal of Physics. Publicado em: 2004-12
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8. Photophysical studies of zinc phthalocyanine and chloroaluminum phthalocyanine incorporated into liposomes in the presence of additives
The photophysical properties of zinc phthalocyanine (ZnPC) and chloroaluminum phthalocyanine (AlPHCl) incorporated into liposomes of dimyristoyl phosphatidylcholine in the presence and absence of additives such as cholesterol or cardiolipin were studied by time-resolved fluorescence, laser flash photolysis and steady-state techniques. The absorbance of the d
Brazilian Journal of Medical and Biological Research. Publicado em: 2004-02
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9. Estudo de laseres semicondutores de cavidades ressonantes não convencionais obtidas por plasma seco
A comprehensive treatment of unconventional micro-cavity lasers is presented. We explore all aspects of the development of these devices, covering from device fabrication, modeling, optimization and damage evaluation of plasma etching techniques, to device characterization. Great emphasis is placed on the spatial ad spectral characteristics of laser emission
Publicado em: 2001
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10. Relativistic plasma shutter for ultraintense laser pulses
A relativistic plasma shutter technique is proposed and tested to remove the sub-100 ps pedestal of a high-intensity laser pulse. The shutter is an ultrathin foil placed before the target of interest. As the leading edge of the laser ionizes the shutter material it will expand into a relativistically underdense plasma allowing for the peak pulse to propagate
American Institute of Physics.
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11. Numerical analysis of weakly nonlinear wave turbulence
We consider the propagation of weakly nonlinear waves such as plasma waves, surface water waves, the interaction of laser beams with matter, particle accelerators, etc. Specifically, we study internal waves in the ocean. Hamilton's principle is used to write the fluid equations in Hamiltonian form in terms of linear eigenmode amplitudes. Numerical studies ar
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12. Spin-lattice relaxation of laser-polarized xenon in human blood
The nuclear spin polarization of 129Xe can be enhanced by several orders of magnitude by using optical pumping techniques. The increased sensitivity of xenon NMR has allowed imaging of lungs as well as other in vivo applications. The most critical parameter for efficient delivery of laser-polarized xenon to blood and tissues is the spin-lattice relaxation ti
The National Academy of Sciences.