106 research outputs found
GRANADA. Planos de población (1834). 1:7.056
Relieve representado por sombreadoIndica los barrios más típicos de la ciudadSeñala los ríos Genil y Darro en la ciuda
Nucleon-nucleus scattering as a test of shell structure of some light mass exotic nuclei
Shell model wave functions have been used to form microscopic g-folding
optical potentials with which elastic scattering data from 8He, 10,11C, and
18,20,22O scattering on hydrogen has been analyzed. Those potentials, the
effective two-nucleon interaction used in their formation, and the shell model
details, then have been used in distorted wave approximation calculations of
differential cross sections from inelastic scattering to the first excited
states of five of those radioactive ions.Comment: 13 pages, 7 figure
Investigation of the 6He cluster structures
The 4He+2n and t+t clustering of the 6He ground state were investigated by
means of the transfer reaction 6He(p,t)4He at 25 MeV/nucleon. The experiment
was performed in inverse kinematics at GANIL with the SPEG spectrometer coupled
to the MUST array. Experimental data for the transfer reaction were analyzed by
a DWBA calculation including the two neutrons and the triton transfer. The
couplings to the 6He --> 4He + 2n breakup channels were taken into account with
a polarization potential deduced from a coupled-discretized-continuum channels
analysis of the 6He+1H elastic scattering measured at the same time. The
influence on the calculations of the 4He+t exit potential and of the triton
sequential transfer is discussed. The final calculation gives a spectroscopic
factor close to one for the 4He+2n configuration as expected. The spectroscopic
factor obtained for the t+t configuration is much smaller than the theoretical
predictions.Comment: 10 pages, 11 figures, accepted in PR
Asymmetry to symmetry transition of Fano line-shape: Analytical derivation
An analytical derivation of Fano line-shape asymmetry ratio has been
presented here for a general case. It is shown that Fano line-shape becomes
less asymmetric as \q is increased and finally becomes completely symmetric in
the limiting condition of q equal to infinity. Asymmetry ratios of Fano
line-shapes have been calculated and are found to be in good consonance with
the reported expressions for asymmetry ratio as a function of Fano parameter.
Application of this derivation is also mentioned for explanation of asymmetry
to symmetry transition of Fano line-shape in quantum confined silicon
nanostructures.Comment: 3 figures, Latex files, Theoretica
Present-day uplift of the western Alps
International audienceCollisional mountain belts grow as a consequence of continental plate convergence and eventuallydisappear under the combined effects of gravitational collapse and erosion. Using a decade ofGPS data, we show that the western Alps are currently characterized by zero horizontal velocityboundary conditions, offering the opportunity to investigate orogen evolution at the time ofcessation of plate convergence. We find no significant horizontal motion within the belt, but GPS andlevelling measurements independently show a regional pattern of uplift reaching ~2.5 mm/yr in thenorthwestern Alps. Unless a low viscosity crustal root under the northwestern Alps locally enhancesthe vertical response to surface unloading, the summed effects of isostatic responses to erosion andglaciation explain at most 60% of the observed uplift rates. Rock-uplift rates corrected from transientglacial isostatic adjustment contributions likely exceed erosion rates in the northwestern Alps. In theabsence of active convergence, the observed surface uplift must result from deep-seated processes
Multiphase induction motor drives - a technology status review
The area of multiphase variable-speed motor drives in general and multiphase induction motor drives in particular has experienced a substantial growth since the beginning of this century. Research has been conducted worldwide and numerous interesting developments have been reported in the literature. An attempt is made to provide a detailed overview of the current state-of-the-art in this area. The elaborated aspects include advantages of multiphase induction machines, modelling of multiphase induction machines, basic vector control and direct torque control schemes and PWM control of multiphase voltage source inverters. The authors also provide a detailed survey of the control strategies for five-phase and asymmetrical six-phase induction motor drives, as well as an overview of the approaches to the design of fault tolerant strategies for post-fault drive operation, and a discussion of multiphase multi-motor drives with single inverter supply. Experimental results, collected from various multiphase induction motor drive laboratory rigs, are also included to facilitate the understanding of the drive operatio
Large enhancement of the sub-barrier fusion probability for a halo nucleus
The fusion-fission cross sections of the He-4 + U-238 and He-6 + U-238 systems have been measured, at Louvain-la-Neuve, for energies around and below the Coulomb barrier, using an array of Si detectors surrounding a UF4 target. The data taken with 4He are in good agreement with previous data and with the coupled channel fusion calculation performed with ECIS. The He-6 data show a regular trend with a large enhancement below the barrier which is attributed to the halo structure of the He-6 nucleus
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