Synchrotron Light Source
Mostrando 1-11 de 11 artigos, teses e dissertações.
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1. Métodos para otimização de abertura dinâmica da nova fonte de luz síncrotron brasileira - Sirius / Methods for optmisation of the dynamic aperture of the new Brazilian synchrotron light source
Um novo anel de armazenamento de elétrons está sendo projetado para a produção de luz síncrotron de alto brilho no Laboratório Nacional de Luz Síncrotron (LNLS), em Campinas. Para atingir um alto brilho, requer-se uma forte focalização do feixe, levando a fortes não-linearidades dos campos magnéticos, o que limita a região de estabilidade do movi
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 08/03/2012
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2. Photon stimulated ion desorption of condensed CO2 at ~ 85 K studied by synchrotron radiation
Photon stimulated ion desorption (PSID) from condensed carbon dioxide has been studied for photon excitation energies ranging from 93 to 193 eV. PSID studies have been performed at the Brazilian synchrotron light source (LNLS), Campinas, during a multi-bunch operation mode of the storage ring. The results showed that after photon excitation several ions deso
Brazilian Journal of Physics. Publicado em: 2006-09
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3. Ionic desorption in valence- and core- excited polymers: poly(vinyl chloride) and poly(vinylidene chloride)
Photon stimulated ion desorption (PSID) studies have been performed in poly(vinyl chloride) (PVC) and poly(vinylidene chloride) (PVDC) using synchrotron radiation, covering from valence to core electron (Cl 2p and C 1s) energy ranges. Data acquisition was performed at the TGM beam line from the Brazilian Synchrotron Light Source (LNLS), operating in a multi-
Brazilian Journal of Physics. Publicado em: 2006-06
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4. Relativistic jets and accretion phenomena associated with galactic and extragalactic black holes
More than a dozen binary star systems hosting stellar-mass black holes have been discovered in our galaxy. Some of them eject collimated relativistic jets with apparent velocities larger than the light speed. These objects have been named microquasars thanks to their similarity with the distant quasars or active nuclei of galaxies that host supermassive blac
Brazilian Journal of Physics. Publicado em: 2005-12
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5. Efeitos de tensão em filmes finos de manganitas estudados por espectroscopia de absorção de raios-X com luz linearmente polarizada
Among the materials exhibiting the Colossal Magnetoresistance e effect, mixed manganite thin films have received special attention due to their potential applications for new generation magneto-eletronic devices. In these systems, the external biaxial strain could be used to tune the magnetism and transport properties if it were possible to settle the exact
Publicado em: 2003
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6. Fotodegradação de polímeros clorados irradiados com a luz síncrotron - I. Emissão de gases
Chlorinated polymers (PVC, PVDC and E-CTFE) were irradiated with white light produced at the Brazilian Synchrotron Light Source (LNLS). The emitted gases were analyzed by mass spectrometry. The spectra were dominated by peaks related to hydrochloric acid, HCl, and chlorine (35Cl). The measured HCl intensity is used to evaluate the sensitivity of the polymers
Química Nova. Publicado em: 2001-06
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7. In situ characterization of beta-amyloid in Alzheimer's diseased tissue by synchrotron Fourier transform infrared microspectroscopy.
We report the first evidence of the structure of beta-amyloid protein as it exists in situ within a slice of human Alzheimer's diseased brain tissue. Using a Fourier transform infrared microspectroscopic technique, areas of interest can be selected for spectral measurements with regions of potential contamination masked. In so doing, it is possible to obtain
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8. The α-helix folds on the millisecond time scale
It has long been believed that nucleation of the α-helix is a very fast reaction, occurring in around 10−7 s. We show here that helix nucleation, in fact, takes place on the millisecond time scale. The rate of α-helix nucleation in two polyalanine-based peptides and in lysine and glutamic acid homopolymers was measured directly by stopped-flow deep UV CD
The National Academy of Sciences.
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9. The complete optical spectrum of liquid water measured by inelastic x-ray scattering
Interaction of light with matter is of paramount importance in nature. The most fundamental property of a material in relation to light is its oscillator strength distribution, i.e., how strongly it absorbs light as a function of wavelength. Once the oscillator strength distribution is determined precisely for a wide enough energy range, the optical constant
National Academy of Sciences.
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10. Subacute neuropathological effects of microplanar beams of x-rays from a synchrotron wiggler.
Microplanar beam radiation therapy has been proposed to treat brain tumors by using a series of rapid exposures to an array of parallel x-ray beams, each beam having uniform microscopic thickness and macroscopic breadth (i.e., microplanar). Thirty-six rats were exposed head-on either to an upright 4-mm-high, 20- or 37-microns-wide beam or to a horizontal 7-m
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11. Subnanosecond motions of tryptophan residues in proteins
The dynamics of protein molecules in the subnanosecond and nanosecond time range were investigated by time-resolved fluorescence polarization spectroscopy. Synchrotron radiation from a storage ring was used as a pulsed light source to excite the single tryptophan residue in a series of proteins. The full width at half maximum of the detected light pulse was