73,342 research outputs found
Asymptotic results for a generalized PĂČlya urn with delay and an applications to clinical trials
In this paper a new PĂČlya urn model is introduced and studied; in particular, a strong law of large numbers and two central limit theorems are proven. This urn generalizes a model studied in Berti et al. (2004), May et al. (2005) and in Crimaldi (2007) and it has natural applications in clinical trials. Indeed, the model include both delayed and missing (or null) responses. Moreover, a connection with the conditional identity in distribution of Berti et al. (2004) is given.
Temperature estimation and slip-line force analytical models for the estimation of the radial forming force in the RARR process of flat rings
open2noIn this study, a mathematical model for the prediction of the temperature evolution in the ring during the radial-axial ring rolling process is developed and used, together with the authorsâ previous results, to determine analytically the flow stress of the material during process. These results, combined with Hill's slip-line field solution adapted to the RARR process, allow a fast and reasonably precise calculation of the radial forming force, a key parameter at the preliminary stage of the process design. The approach is validated by applying the proposed model to a case available in the literature and comparing the analytical results with those of the laboratory experiment and FEM simulation. Following the successful comparison, the models were applied to a large variety of flat rings, comparing analytical predictions with the results of FEM simulations. The accuracy of the analytical calculation and the reliability of the proposed models, for different ring configuration and process parameters, are presented and discussed.embargoed_20190501Quagliato, Luca; Berti, GuidoQuagliato, Luca; Berti, Guid
Leucine-rich repeat kinase 2 positively regulates inflammation and down-regulates NF-ĂÂșB p50 signaling in cultured microglia cells
7openopenRusso, Isabella; Berti, Giulia; Plotegher, Nicoletta; Bernardo, Greta; Filograna, Roberta; Bubacco, Luigi; Greggio, Elisa*Russo, Isabella; Berti, Giulia; Plotegher, Nicoletta; Bernardo, Greta; Filograna, Roberta; Bubacco, Luigi; Greggio, Elis
Berti Qurâanic Amulets
The Berti live in the Province of North Darfur in the Sudan.
They are sedentary people whose main livelihood is based on rain
cultivation and animal husbandry (for more details on the Berti see
Holy 1974). For several centuries the Berti have spoken their own
dialect of the Arabic language. They are Muslim, following the
Maliki school of Islamic Law. Among the Berti, Islam is
disseminated and taught by their religious men, locally referred to
fugara, a term translated as jurisconsults, clergymen, Sufi mendicants or religious officiants (see Trimingham 1949:140, 1968:61
and 130; Yusuf 1976:116; among others). As professionals, Berti
religious men render a variety of services to their clients. They
teach the Qurâan, preside over rituals, and treat the sick. In this article I shall restrict myself to the provision of âamuletsâ which are
believed to help their owners to achieve certain objectives
Realistic Exact Solution for the Exterior Field of a Rotating Neutron Star
A new six-parametric, axisymmetric and asymptotically flat exact solution of
Einstein-Maxwell field equations having reflection symmetry is presented. It
has arbitrary physical parameters of mass, angular momentum, mass--quadrupole
moment, current octupole moment, electric charge and magnetic dipole, so it can
represent the exterior field of a rotating, deformed, magnetized and charged
object; some properties of the closed-form analytic solution such as its
multipolar structure, electromagnetic fields and singularities are also
presented. In the vacuum case, this analytic solution is matched to some
numerical interior solutions representing neutron stars, calculated by Berti &
Stergioulas (Mon. Not. Roy. Astron. Soc. 350, 1416 (2004)), imposing that the
multipole moments be the same. As an independent test of accuracy of the
solution to describe exterior fields of neutron stars, we present an extensive
comparison of the radii of innermost stable circular orbits (ISCOs) obtained
from Berti & Stergioulas numerical solutions, Kerr solution (Phys. Rev. Lett.
11, 237 (1963)), Hartle & Thorne solution (Ap. J. 153, 807, (1968)), an
analytic series expansion derived by Shibata & Sasaki (Phys. Rev. D. 58 104011
(1998)) and, our exact solution. We found that radii of ISCOs from our solution
fits better than others with realistic numerical interior solutions.Comment: 13 pages, 13 figures, LaTeX documen
Quasi-periodic solutions of completely resonant forced wave equations
We prove existence of quasi-periodic solutions with two frequencies of
completely resonant, periodically forced nonlinear wave equations with periodic
spatial boundary conditions. We consider both the cases the forcing frequency
is: (Case A) a rational number and (Case B) an irrational number.Comment: 25 pages, 1 figur
UM Astrophysicist Joins Editorial Board of Physical Review Letters
APS fellow Emanuele Berti rises from featured writer to divisional associate edito
Ln(3) and Black Hole Entropy
We review an idea that uses details of the quasinormal mode spectrum of a
black hole to obtain the Bekenstein-Hawking entropy of in Loop Quantum
Gravity. We further comment on a recent proposal concerning the quasinormal
mode spectrum of rotating black holes. We conclude by remarking on a recent
proposal to include supersymmetry.Comment: Contribution to the Proceedings of the 3rd International Symposium on
Quantum Theory and Symmetries, Cincinnati, September 2003, added references
to the numerical investigations of Kerr quasinormal modes by Berti et. a
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