59 research outputs found
Detection of static eccentricity fault in PSH induction motor by using external magnetic flux density
The objective of this paper is to make a clear and thorough investigation about the effectiveness of Motor Current Signature Analysis (MCSA) for detecting default indexes of static eccentricity in (Principal Slot Harmonics) PSH induction motor. The obtained results using traditional technique (MCSA) are compared with spectrums of external magnetic flux density extracted from healthy and faulty motors. The work is carried out with transient finite element method (FEM) simulations considering motor operation under nominal mechanical load, the notching nature of stator and rotor and the non-linearity behavior of ferromagnetic material are taking into account.Keywords: induction motor; static eccentricity; FEM, PSH; MCSA; magnetic flux densit
Time delay in the Einstein-Straus solution
The time delay of strong lensing is computed in the framework of the
Einstein-Straus solution. The theory is compared to the observational bound on
the time delay of the lens SDSS J1004+4112.Comment: 20 pages, 4 tables, 1 figur
From Tetraquark to Hexaquark: A Systematic Study of Heavy Exotics in the Large Limit
A systematic study of multiquark exotics with one or heavy quarks in
the large limit is presented. By binding a chiral soliton to a heavy
meson, either a normal -quark baryon or an exotic -quark baryon
is obtained. By replacing the heavy quark with heavy antiquarks, exotic
-quark and -quark mesons are obtained. When , they are
just the normal triquark baryon , the exotic pentaquark baryon , tetraquark di-meson and the hexaquark
di-baryon respectively. Their
stabilities and decays are also discussed. In particular, it is shown that the
``heavy to heavy'' semileptonic decays are described by the Isgur--Wise form
factors of the normal baryons.Comment: 14 pages in REVTeX, no Figure
Four-quark stability
The physics of charm has become one of the best laboratories exposing the
limitations of the naive constituent quark model and also giving hints into a
more mature description of meson spectroscopy, beyond the simple
quark--antiquark configurations. In this talk we review some recent studies of
multiquark components in the charm sector and discuss in particular exotic and
non-exotic four-quark systems, both with pairwise and many-body forces.Comment: 6 pages. Article based on the presentations by J. Vijande and J.-M.
Richard at the Fifth Workshop on Critical Stability, Erice, Sicil
Pentaquark baryons in SU(3) quark model
We study the SU(3) group structure of pentaquark baryons which are made of
four quarks and one antiquark. The pentaquark baryons form {1}, {8}, {10},
{10}-bar, {27}, and {35} multiplets in SU(3) quark model. First, the flavor
wave functions of all the pentaquark baryons are constructed in SU(3) quark
model and then the flavor SU(3) symmetry relations for the interactions of the
pentaquarks with three-quark baryons and pentaquark baryons are obtained.Comment: REVTeX, 36 pages, 8 figures, references added, section for mass sum
rules is added, to appear in Phys. Rev.
Search for Flavoured Multiquarks in a Simple Bag Model
We use a bag model to study flavoured mesonic and baryonic
states, where one heavy quark is associated with
light quarks or antiquarks, and search for possible stable multiquarks. No
bound state is found. However some states lie not too high above their
dissociation threshold, suggesting the possibility of resonances, or perhaps
bound states in improved models.Comment: REVTEX, VERSION 3.
Health & Demographic Surveillance System Profile: The Taabo Health and Demographic Surveillance System, Côte d'Ivoire
The Taabo Health and Demographic Surveillance System (HDSS) is located in south-central Côte d'Ivoire, approximately 150 km north-west of Abidjan. The Taabo HDSS started surveillance activities in early 2009 and the man-made Lake Taabo is a key eco-epidemiological feature. Since inception, there has been a strong interest in research and integrated control of water-associated diseases such as schistosomiasis and malaria. The Taabo HDSS has generated setting-specific evidence on the impact of targeted interventions against malaria, schistosomiasis and other neglected tropical diseases. The Taabo HDSS consists of a small town, 13 villages and over 100 hamlets. At the end of 2013, a total population of 42 480 inhabitants drawn from 6707 households was under surveillance. Verbal autopsies have been conducted to determine causes of death. Repeated cross-sectional epidemiological surveys on approximately 5-7% of the population and specific, layered-on haematological, parasitological and questionnaire surveys have been conducted. The Taabo HDSS provides a database for surveys, facilitates interdisciplinary research, as well as surveillance, and provides a platform for the evaluation of health interventions. Requests to collaborate and to access data are welcome and should be addressed to the secretariat of the Centre Suisse de Recherches Scientifiques en Côte d'Ivoire: [[email protected]
Heavy Quark Symmetry and the Skyrme Model
We present a consistent way of describing heavy baryons containing a heavy
quark as bound states of an soliton and heavy mesons. The resulting
mass formula reveals the heavy quark symmetry explicitly. By extending the
model to the orbitally excited states, we establish the generic structure of
the heavy baryon spectrum. As anticipated from the heavy quark spin symmetry,
the -factor denoting the hyperfine splitting constant {\em vanishes} and the
baryons with the same angular momentum of light degrees of freedom form
degenerate doublets. This approach is also applied to the pentaquark exotic
baryons, where the conventional -factor plays no more a role of the
hyperfine constant. After diagonalizing the Hamiltonian of order , we
get the degenerate doublets, which implies the vanishing of genuine hyperfine
splitting.Comment: REVTeX, 33 pages, 3 figures included, SNUTP-94/13 (revised
Search for the pentaquark via the P^0_{{c bar}s} --> phi,pi,p decay
We report results of the first search for the pentaquark P_{{c bar}s} which
is predicted to be a doublet of states: P^0_{{c bar}s}=({c bar} s u u d) and
P^-_{{c bar}s}=({c bar} s d d u). A search was made for the decay P^0_{{c
bar}s} --> phi,pi,p in data from Fermilab experiment E791, in which 500 GeV/c
pi^- beam interacted with nuclear targets. We present upper limits at 90%
confidence level for the ratio of cross section times branching fraction of
this decay to that for the decay D_s --> phi,pi. The upper limits are 0.031 and
0.063 for M(P^0_{{c bar}s}) = 2.75 and 2.86 GeV/c^2, respectively, assuming a
P^0_{{c bar}s} lifetime of 0.4 ps.Comment: 9 pages postscript file, 11 pages Latex file, one Figure. Submitted
to Physical Review Letter
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