Particle Collision
Mostrando 13-24 de 25 artigos, teses e dissertações.
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13. Production of 1s2s2p4P states by transfer-loss cascades in O5+ collisions with he and H2 targets
Single differential cross-sections for transfer-loss (TL) leading to the production of O5+(1s2s³S)nl4L states were computed for 0.2-1.2 MeV/u collisions of O5+(1s²2s) ions with He and H2 targets. At these collision energies, 1s loss is significant and electron transfer to n = 3-4 levels is dominant. Furthermore, due to spin conservation, quartet states can
Brazilian Journal of Physics. Publicado em: 2006-06
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14. Comparative study of vibracional excitation of hydrogen molecules by electron and positron impact / Estudo comparativo das seções de choque de excitações vibracionais de moleculas de hidrogenio por impacto de positrons e eletrons
Here we report a comparative calculation of both integral and differential vibrational excitation cross sections of low energy positron and electron scattering against Hydrogen molecules (H2). For these calculations we have used the Schwinger Multichannel (SMC) Method [1] for positron collision [2] and electron collision [3]. Using a set of SMC scattering am
Publicado em: 2006
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15. Orbital evolution and maneuvers around non-spherical bodies / Evolução orbital e manobras em torno de corpos não-esféricos
In the last years several asteroids had their shapes identified using images from space probes or through the indirect radar data determination. In a general way, these asteroids have forms quite different from spherical. Conventional spherical harmonic representations of the gravitational potential of such bodies require expansions of high degree and order,
Publicado em: 2006
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16. High-pT results from the STAR experiment at RHIC
High-pT measurements in relativistic heavy ion collisions provide a unique set of tools to investigate the early stages of the collision. In this paper we report the high-pT measurements of inclusive hadron spectra, azimuthal anisotropies and two particle correlations performed by the STAR detector for 200 GeV Au+Au, p+p and d+Au collisions at RHIC. The resu
Brazilian Journal of Physics. Publicado em: 2004-03
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17. Probing a color glass condensate in high energy heavy ion collisions
At very high energies, the partons in the nuclear wavefunction form a color glass condensate. Since the occupation number of partons in the color glass condensate is large, classical methods can be used to compute multi-particle production in the initial instants of a high energy heavy ion collision. Non-perturbative expressions are derived relating the dist
Brazilian Journal of Physics. Publicado em: 2003-06
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18. Ressonancia parametrica em modelos de estrelas de neutrons
The Parametric Resonance phenomenon is nowadays the most accepted model to explain the huge production of matter in the pos-infiationary Universe. In this work we show that this phenomenon can also appears in models of neutron stars describing the production of photons in its interior. The Chapter 1 is a general introduction to the neutron stars. We describe
Publicado em: 2003
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19. Estabilização de latex polimericos por sorção de solventes organicos
The colloidal stability with regard to NaCI addition of homopolymer (PS-M and PS-LEV) polystyrene latexes and copolymer (P(SBMA), PS/PBMA and PBMA/PS) poly[styrene-co- butylmethacrylate)] latexes was modified by particle swelling with toluene and chloroform vapor, at 25°C. The latexes were obtained by aqueous emulsion polymerization. K2S2O4 and Na2S204 were
Publicado em: 1998
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20. Aggregation and disaggregation kinetics of human blood platelets: Part II. Shear-induced platelet aggregation.
A population balance equation (PBE) mathematical model for analyzing platelet aggregation kinetics was developed in Part I (Huang, P. Y., and J. D. Hellums. 1993. Biophys. J. 65: 334-343) of a set of three papers. In this paper, Part II, platelet aggregation and related reactions are studied in the uniform, known shear stress field of a rotational viscometer
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21. Aggregation and disaggregation kinetics of human blood platelets: Part I. Development and validation of a population balance method.
Hydrodynamic shear stress of sufficient intensity is known to cause platelet activation and aggregation and to alter the effects of biochemical platelet agonists and antagonists. In this work, a population balance equation (PBE) model is developed for analysis of platelet aggregation and disaggregation kinetics under the influence of a shear field. The model
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22. Entropy, Dynamics, and Molecular Chaos
With the help of simple probabilistic models of Kac and McKean, we discuss the meaning of the generalized expression for entropy that was recently introduced by our group and compare it with Boltzmann's expression. We emphasize the fact that Boltzmann's formulation in terms of the single particle distribution function, f1, requires very restricted assumption
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23. Tracking Retrograde Flow in Keratocytes: News from the FrontV⃞
Actin assembly at the leading edge of the cell is believed to drive protrusion, whereas membrane resistance and contractile forces result in retrograde flow of the assembled actin network away from the edge. Thus, cell motion and shape changes are expected to depend on the balance of actin assembly and retrograde flow. This idea, however, has been undermined
The American Society for Cell Biology.
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24. Hydrodynamic effects and receptor interactions of platelets and their aggregates in linear shear flow.
We have modeled platelet aggregation in a linear shear flow by accounting for two body collision hydrodynamics, platelet activation and receptor biology. Considering platelets and their aggregates as unequal-sized spheres with DLVO interactions (psi(platelet) = -15 mV, Hamaker constant = 10(-19) J), detailed hydrodynamics provided the flow field around the c