Spectral Lines
Mostrando 37-48 de 93 artigos, teses e dissertações.
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37. Desenvolvimento de um sistema de imageamento usando a tomografia por coerÃncia Ãptica no domÃnio temporal e de Fourier
In this dissertation, we describe the basic theory and details of the implementation of three experimental optical coherence tomography systems, two in the time domain and one in the spectral (Fourier) domain. Optical coherence tomography (OCT) is a non invasive optical imaging method, capable of producing cross-sectional images of materials and biological t
Publicado em: 2006
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38. Vocal quality in asthmatics with and without paradoxal vocal fold dysfunction: perceptual, acoustic and physiologic correlates / Qualidade vocal em individuos asmáticos com e sem disfunção paradoxal de pregas vocais: correlatos perceptivo-auditivos, acusticos e fisiologicos
Objective: investigating the perceptual, acoustic and physiological vocal quality of a group of asthmatic individuals with paradoxical vocal fold dysfunction (PVFD) in relation to a group of asthmatic individuals without PVFD and a group of individuals without breathing problems. Methods: recording of acoustic and electroglottographic speech data from 9 indi
Publicado em: 2006
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39. Processos de aquecimento na alta atmosfera estelar: emissão coronal em raio-x e emissão cromosférica em CaII
In the present work we study the processes of heating in the high stellar atmosphere, with base in an analysis of behavior of the cromospheric and coronal emission for a sample of single stars classified as giant in the literature. The evolutionary status of the stars of the sample was determined from HIPPARCOS satellite trigonometric parallax measurements a
Publicado em: 2006
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40. Characterization of Cs2NaAIF6:Cr3+ and Cs2NaGaF6:Fe3+ single crystals by electron paramagnetic resonance / Caracterização dos monocristais Cs2NaAIF6:Cr3+ e Cs2NaGaF6:Fe3+ por meio de ressonancia paramagnetica eletronica
The interest in materials with large bands of absorption and luminescence is due to the possibility of their applications as tunable solid state lasers. The crystals Cs2NaAlF6:Cr3+ and Cs2NaGaF6:Fe3+ present these properties and , naturally, some of their physical characteristics, such as the crystal field , are decisive for their optical activity and should
Publicado em: 2006
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41. Diferentes propriedades físicas de condensações da região do escorpião / Physical properties of condensations of the scorpius region
Neste trabalho, propomos o estudo das propriedades físicas de 32 condensações localizadas na região do Escorpião, cujas coordenadas galácticas estão no intervalo 344° < l < 347° e 6° > b > -8. Suas propriedades físicas foram comparadas com as propriedades de condensações observadas em outras nuvens escuras. Procuramos destacar caract
Publicado em: 2005
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42. Diferentes propriedades físicas de condensações da região do escorpião / Physical properties of condensations of the scorpius region
Neste trabalho, propomos o estudo das propriedades físicas de 32 condensações localizadas na região do Escorpião, cujas coordenadas galácticas estão no intervalo 344° < l < 347° e 6° > b > -8. Suas propriedades físicas foram comparadas com as propriedades de condensações observadas em outras nuvens escuras. Procuramos destacar caract
Publicado em: 2005
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43. Spectroscopic measurements in a titanium vacuum arc with different ambient gases
Spectral emission lines from a low pressure d-c arc discharge with a Ti cathode were studied in various ambient gases; N2, O2, and Ar. Light from the plasma was detected by an optical spectrometer multichannel analyzer (OSMA). The spectral intensities of Ti, Ti+, Ar and N2 were measured as a function of the gas pressure in the range 5 × 10-3 - 0.5 mbar. The
Brazilian Journal of Physics. Publicado em: 2004-12
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44. Determination of plasma temperature by a semi-empirical method
Doppler or Stark line broadening effects are generally used to determinate plasma temperature. These methods are difficult to apply to spectra of highly ionized atoms due to the short wavelengths involved. It is not at all easy to achieve sufficient wavelength resolution in this spectral range. In this case, a spectroscopic technique based on the relative in
Brazilian Journal of Physics. Publicado em: 2004-12
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45. Study of excitation rates in a hollow cathode discharge
In this work a dc discharge with a copper hollow cathode in argon used for deposition applications is investigated using atomic emission spectroscopy. Typical discharge parameters during our investigation are pressures between 80 and 200 Pa and current densities up to 7 mA cm-2. The radial light intensity profiles of some selected copper and argon lines were
Brazilian Journal of Physics. Publicado em: 2003-06
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46. Estudos de plasmas a altas temperaturas por espectroscopia visivel e ultravioleta no vacuo
In this thesis we present results on a wide variety of experiments related to magnetically confined plasma spectroscopy. We discuss the applicability of atomic models to our spectroscopy measurements, spectrometers absolute calibration, as well as the determination of many parameters of the plasma confined in the tokamak NOVA-UNICAMP. For these measurements,
Publicado em: 2003
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47. Caracterização de um sistema imageador infravermelho termal através de suas resoluções espacial e radiométrica / Characterization of a thermal infrared line scanner trough its spatial and radiometric resolutions
The thermal infrared spectral bands in airborne sensors are still little explored in Brazil. The Institute of Advanced Studies (IEAv) at the Aerospace Technical Center (CTA) developed the Thermal Infrared Imaging System (SISIMI), an aerial surveillance prototype sensor operating in the 8 to 12.5 um band with a rotating imaging scanner of 720 lines/s. The obj
Publicado em: 2002
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48. Coordenação local do Eu(III) em híbridos orgânicos/inorgânicos emissores de luz branca
Eu3+ luminescence and EXAFS (Extended X-ray Absorption Fine Structure) results are presented for organic-inorganic hybrid gel hosts composed of a siliceous network to which small chains of oxyethylene units are covalently grafted by means of urea bridges. Coordination numbers for Eu3+ ions range from 12.8 to 9.7 with increasing Eu3+ concentration while the E
Química Nova. Publicado em: 2001-08