297 research outputs found

    Simultaneous Determination of Amlodipine and Valsartan

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    A spectrophotometric method was developed for simultaneous determination of amlodipine (Aml) and valsartan (Val) without previous separation. In this method amlodipine in methanolic solution was determined using zero order UV spectrophotometry by measuring its absorbency at 360.5 nm without any interference from valsartan

    Production of radioactive ion beams using the in-flight technique

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    Reactions with a heavy projectile incident on a light target can be used for the efficient in-flight production of secondary radioactive beams. An overview of this technique is given using data on 17F beams produced via the p(17O, 17F)n and d(16O, 17F)n reactions. With primary 16,17O beam currents of 100 pnA, intensities of up to 2×106 17F/s on target were achieved. Using this beam, the p(17F, α) 14O reaction was measured

    Stellar reactions with short-lived nuclei: 17F(p,α)14O

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    A method has been developed that can provide beams of many short-lived nuclei of interest in nucleosynthesis along the rp process path. With a 17F beam (T1/2=64s) the excitation function of the 17F(p, α)14O reaction was measured to determine properties of excited states in 18Ne. These states influence the rate of the 14O(α, p)17F reaction which is important for understanding energy generation and nucleosynthesis in x-ray bursts. The present direct measurements yield a pattern of resonances and cross sections which differ substantially from previous estimates

    Widths of astrophysically important resonances in 18Ne

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    The astrophysically important reaction 14O(α,p)17F has been studied through a measurement of the time-inverse p(17F,α)14O reaction using a radioactive 17F beam. Resonance parameters for several states above an excitation energy of 7 MeV in 18Ne have been obtained. Through a measurement of the partial widths for elastic and inelastic proton scattering, it was determined that for these resonances the contribution of the 14O(α,p)17F* branch populating the first excited state in 17F is small. The results indicate that the contribution of resonances above Ex=7 MeV to the astrophysical (α,p) reaction rate is smaller than was previously assumed

    Collisional and Radiative Processes in Optically Thin Plasmas

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    Most of our knowledge of the physical processes in distant plasmas is obtained through measurement of the radiation they produce. Here we provide an overview of the main collisional and radiative processes and examples of diagnostics relevant to the microphysical processes in the plasma. Many analyses assume a time-steady plasma with ion populations in equilibrium with the local temperature and Maxwellian distributions of particle velocities, but these assumptions are easily violated in many cases. We consider these departures from equilibrium and possible diagnostics in detail

    Self-consistent field theory of polarized BEC: dispersion of collective excitation

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    We suggest the construction of a set of the quantum hydrodynamics equations for the Bose-Einstein condensate (BEC), where atoms have the electric dipole moment. The contribution of the dipole-dipole interactions (DDI) to the Euler equation is obtained. Quantum equations for the evolution of medium polarization are derived. Developing mathematical method allows to study effect of interactions on the evolution of polarization. The developing method can be applied to various physical systems in which dynamics is affected by the DDI. Derivation of Gross-Pitaevskii equation for polarized particles from the quantum hydrodynamics is described. We showed that the Gross-Pitaevskii equation appears at condition when all dipoles have the same direction which does not change in time. Comparison of the equation of the electric dipole evolution with the equation of the magnetization evolution is described. Dispersion of the collective excitations in the dipolar BEC, either affected or not affected by the uniform external electric field, is considered using our method. We show that the evolution of polarization in the BEC leads to the formation of a novel type of the collective excitations. Detailed description of the dispersion of collective excitations is presented. We also consider the process of wave generation in the polarized BEC by means of a monoenergetic beam of neutral polarized particles. We compute the possibilities of the generation of Bogoliubov and polarization modes by the dipole beam.Comment: 16 pages, 15 figures. arXiv admin note: substantial text overlap with arXiv:1106.082
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