47 research outputs found

    Detection of static eccentricity fault in PSH induction motor by using external magnetic flux density

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    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

    From Tetraquark to Hexaquark: A Systematic Study of Heavy Exotics in the Large NcN_c Limit

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    A systematic study of multiquark exotics with one or Nc−1N_c-1 heavy quarks in the large NcN_c limit is presented. By binding a chiral soliton to a heavy meson, either a normal NcN_c-quark baryon or an exotic (Nc+2)(N_c+2)-quark baryon is obtained. By replacing the heavy quark with Nc−1N_c-1 heavy antiquarks, exotic (2Nc−2)(2N_c-2)-quark and 2Nc2N_c-quark mesons are obtained. When Nc=3N_c = 3, they are just the normal triquark baryon QqqQqq, the exotic pentaquark baryon QqˉqˉqˉqˉQ\bar q\bar q\bar q\bar q, tetraquark di-meson QˉQˉqq\bar Q \bar Q qq and the hexaquark di-baryon QˉQˉqˉqˉ barqqˉ\bar Q \bar Q \bar q \bar q\ bar q \bar q 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

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    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

    Health & Demographic Surveillance System Profile: The Taabo Health and Demographic Surveillance System, Côte d'Ivoire

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    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]

    ANALYSIS OF INDUCTION MOTOR WITH BROKEN BARS AND CONSTANT SPEED USING CIRCUIT-FIELD COUPLED METHOD

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    The paper presents the use of the two-dimensional finite element method for modeling the three-phase squirrel-cage induction motor by using circuit coupled method. In order to analyze the machine performances, the voltage source is considered. The Ansys magnetic analysis software is used for calculating the magnetic field of an induction motor having a cage fault. The experimental results prove that the proposed approach constitutes a useful tool for the study and diagnostics of induction motors.</p
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