7,493 research outputs found
Correlations and charge distributions of medium heavy nuclei
The effects of long- and short-range correlations on the charge distributions
of some medium and heavy nuclei are investigated. The long-range correlations
are treated within the Random Phase Approximation framework and the short-range
correlations with a model inspired to the Correlation Basis Function theory.
The two type of correlations produce effects of the same order of magnitude. A
comparison with the empirical charge distribution difference between 206Pb and
205Tl shows the need of including both correlations to obtain a good
description of the data.Comment: 20 pages, Latex, accepted for publication in Jour. Phys.
Effects of state dependent correlations on nucleon density and momentum distributions
The proton momentum and density distributions of closed shell nuclei are
calculated within a model treating short--range correlations up to first order
in the cluster expansion. The validity of the model is verified by comparing
the results obtained with purely scalar correlations with those produced by
finite nuclei Fermi Hypernetted Chain calculations. State dependent
correlations are used to calculate momentum and density distributions of 12C,
16O, 40Ca, and 48Ca, and the effects of their tensor components are studied.Comment: 16 pages, latex, 8 figures, accepted for publication in Phys. Rev.
Letter from C. O. Mailloux to Newport Illuminating Co, copy to John Yale
https://digitalcommons.salve.edu/ochre-court/1167/thumbnail.jp
Evaluation of the comparative efficacy and safety of artemether-lumefantrine, artesunate-amodiaquine and artesunate-amodiaquine-chlorpheniramine (Artemoclo™) for the treatment of acute uncomplicated malaria in Nigerian children.
OBJECTIVE: To evaluate the comparative efficacy and safety of artemether-lumefantrine (AL), artesunate-amodiaquine (ASAQ) and artesunate-amodiaquine-chlorpheniramine (AQC) for the treatment of acute uncomplicated malaria among Southwest Nigerian children. SUBJECTS AND METHODS: One hundred and sixty children aged 6 months to 14 years with acute uncomplicated malaria were randomized to AL (n = 53), ASAQ (n = 53), or AQC (n = 54). Enrollees were seen daily on days 0-3 and then on days 7, 14, 21, 28 and 42 for clinical and parasitological evaluations. Paired samples of genomic DNA at enrolment and at the time of recurrent parasitaemia were genotyped using nested PCR to distinguish between reinfection and recrudescence. Detailed haematological and biochemical evaluations were carried out in a subset of enrollees on days 0, 7 and 28 as part of a safety evaluation. RESULTS: Of the 160 children, 144 (90%) completed the study. The mean fever clearance times and parasite clearance times for AL, ASAQ and AQC were comparable (p = 0.94 and p = 0.122, respectively). On day 14, the adequate clinical and parasitological response (ACPR) for AL and AQC was 100% and for ASAQ it was 90% (p = 0.39). The PCR-uncorrected results on days 28 and 42 and the ACPR-corrected results on day 42 were similar for all drugs (p = 0.62 and p = 0.56, respectively). AQC resulted in the best parasite clearance and haematological recovery on day 2 (p = 0.022 and p = 0.018, respectively). Biochemical parameters were not adversely affected by the three artemisinin-based combination therapies (ACTs) and these were well tolerated. CONCLUSION: The three ACTs were efficacious and safe, but AQC resulted in a better haematological recovery on day 2 and higher cure rates throughout the study period
Ground state of N=Z doubly closed shell nuclei in CBF theory
The ground state properties of N=Z doubly closed shell nuclei are studied
within correlated basis function theory. A truncated version of the Urbana v14
realistic potential, with spin, isospin and tensor components, is adopted,
together with state dependent correlations. Fermi hypernetted chain integral
equation and single operator chain approximation are used to evaluate density,
distribution function and ground state energy of 16O and 40Ca. The results
favourably compare with the available, variational MonteCarlo estimates and
provide a first substantial check of the accuracy of the cluster summation
method for state dependent correlations. We achieve in finite nuclei at least
the same level of accuracy in the treatment of non central interactions and
correlations as in nuclear matter. This opens the way for a microscopic study
of medium heavy nuclei ground state using present days realistic hamiltonians.Comment: 35 pages (LateX) + 3 figures. Phys.Rev.C, in pres
Deuteron distribution in nuclei and the Levinger's factor
We compute the distribution of quasideuterons in doubly closed shell nuclei.
The ground states of O and Ca are described in coupling
using a realistic hamiltonian including the Argonne and the
Urbana IX models of two-- and three--nucleon potentials, respectively. The
nuclear wave function contains central and tensor correlations, and correlated
basis functions theory is used to evaluate the distribution of neutron-proton
pairs, having the deuteron quantum numbers, as a function of their total
momentum. By computing the number of deuteron--like pairs we are able to
extract the Levinger's factor and compare to both the available experimental
data and the predictions of the local density approximation, based on nuclear
matter estimates. The agreement with the experiments is excellent, whereas the
local density approximation is shown to sizably overestimate the Levinger's
factor in the region of the medium nuclei.Comment: 26 pages, 8 figures, typeset using REVTe
One Body Density Matrix, Natural Orbits and Quasi Hole States in 16O and 40Ca
The one body density matrix, momentum distribution, natural orbits and quasi
hole states of 16O and 40Ca are analyzed in the framework of the correlated
basis function theory using state dependent correlations with central and
tensor components. Fermi hypernetted chain integral equations and single
operator chain approximation are employed to sum cluster diagrams at all
orders. The optimal trial wave function is determined by means of the
variational principle and the realistic Argonne v8' two-nucleon and Urbana IX
three-nucleon interactions. The correlated momentum distributions are in good
agreement with the available variational Monte Carlo results and show the well
known enhancement at large momentum values with respect to the independent
particle model. Diagonalization of the density matrix provides the natural
orbits and their occupation numbers. Correlations deplete the occupation number
of the first natural orbitals by more than 10%. The first following ones result
instead occupied by a few percent. Jastrow correlations lower the spectroscopic
factors of the valence states by a few percent (~1-3%) and an additional ~8-12%
depletion is provided by tensor correlations. It is confirmed that short range
correlations do not explain the spectroscopic factors extracted from (e,e'p)
experiments. 2h-1p perturbative corrections in the correlated basis are
expected to provide most of the remaining strength, as in nuclear matter.Comment: 25 pages, 9 figures. Submitted to Phys.Rev.
Two-nucleon emission in the longitudinal response
The contribution of the two-nucleon emission in the longitudinal response for
inclusive electron scattering reactions is studied. The model adopted to
perform the calculations is based upon Correlated Basis Function theory but it
considers only first order terms in the correlation function. The proper
normalization of the wave function is ensured by considering, in addition to
the usually evaluated two-point diagrams, also the three-point diagrams.
Results for the 12C nucleus in the quasi-elastic region are presented.Comment: 7 pages, 4 Postscript figure
Thermodynamic Geometry and Phase Transitions in Kerr-Newman-AdS Black Holes
We investigate phase transitions and critical phenomena in Kerr-Newman-Anti
de Sitter black holes in the framework of the geometry of their equilibrium
thermodynamic state space. The scalar curvature of these state space Riemannian
geometries is computed in various ensembles. The scalar curvature diverges at
the critical point of second order phase transitions for these systems.
Remarkably, however, we show that the state space scalar curvature also carries
information about the liquid-gas like first order phase transitions and the
consequent instabilities and phase coexistence for these black holes. This is
encoded in the turning point behavior and the multi-valued branched structure
of the scalar curvature in the neighborhood of these first order phase
transitions. We re-examine this first for the conventional Van der Waals
system, as a preliminary exercise. Subsequently, we study the Kerr-Newman-AdS
black holes for a grand canonical and two "mixed" ensembles and establish novel
phase structures. The state space scalar curvature bears out our assertion for
the first order phase transitions for both the known and the new phase
structures, and closely resembles the Van der Waals system.Comment: 1 + 41 pages, LaTeX, 46 figures. Discussions, clarifications and
references adde
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