The effective insulation design of the stress grading (SG) system in form-wound stator coils is essential for preventing partial discharges and excessive heat generation under pulse-width modulation excitation. This paper proposes a method to find the optimal insulation design of the SG system aimed at reducing the dielectric and thermal stresses in the machine coil. The non-uniform transmission line model is used to predict the voltage propagation along the overhang, SG, and slot regions considering the variation in the physical properties of the insulation layers. The machine coil parameters for different insulation materials are calculated by using the finite element method. Two optimization algorithms, fmincon and particle swarm optimization (PSO), are applied and compared to find the optimal thickness and material properties of each insulation layer as well as the length and location of the SG system. The results under different rise-time excitation show that the optimized geometry by using PSO can produce a higher reduction in the dielectric and thermal stresses, as well as in the maximum overvoltage along the machine coil than the original geometry and the optimized geometry using fmincon. The machine coil model is validated by means of comparisons with experimental measurements.
The present study was undertaken in order to investigate the role of gentamicin in the gene expression of toxA in Pseudomonas aeruginosa isolated from cow mastitis. A total of ten P. aeruginosa strains originally isolated from cows infected with mastitis. Agar dilution methodology was performed to determine the minimal inhibitory concentration of gentamicin, all of which developed resistance toward gentamicin. The findings presented here demonstrated that all these strains harboured toxA depending on PCR-based assay. Nonetheless, RT-PCR technique revealed a wide variation in expression of toxA. Moreover, the cultivation of P. aeruginosa in the presence of gentamicin, significantly (P< 0.05), induced the expression of toxA, in addition to th
... Show MoreScorpions and spiders belong to the class Arachnida in phylum Arthropoda. Scorpions are easily distinguished by median eyes on obvious the center of the carapace and have one pair, and lateral eyes have 2-8 in some species. Scorpions do not have good eyesight so the median eyes have always been simple and they are more sensitive than the lateral pairs. They have anterior median eyes (AME) with narrow field of view and pairs of lateral eyes (LE) with more sensitivity and response to light. Family Buthidae have 2-6 lateral eyes in Compsobuthus Mesobuthus, Hottentotta, while Vaejovidae, Chactidae and Chaerilidae have 2 pairs of lateral eyes. In addition, 3 pairs are found in Orthochirus and Androctonus. Spiders have six eyes in family Pholicid
... Show MoreBetween decline and appearing dichotomy, art history comes to announce birth of an era that glories past and find new names that are emerged from yearning to past and represented by neo-classical, By refusing the previous approaches and create topics that touché culture and derived from it through s revitalizing ideal beauty standards. One of neo-classical artists, who tried to simulate the classical works, is (Jean-Auguste-Dominique Ingres), who put framework for semantic aesthetic of the art form by revitalizing past glories and deeply searching myths and cultures through finding special artistic features that emphasizes artist own stylistics and identity. This research studies artistic features of women form in (Jean-Auguste-D
The Skyrme–Hartree–Fock (SHF) method with MSK7 Skyrme parameter has been used to investigate the ground-state properties for two-neutron halo nuclei 6He, 11Li, 12Be and 14Be. These ground-state properties include the proton, neutron and matter density distributions, the corresponding rms radii, the binding energy per nucleon and the charge form factors. These calculations clearly reveal the long tail characterizing the halo nuclei as a distinctive feature.
The current research aims to evaluate the appraisal form for Arabic language teachers in light of comprehensive quality standards by designing standards for the competencies of primary school teacher in accordance with comprehensive quality requirements. The researcher adopted the descriptive approach. The research community included the Arabic language supervisors in the Education Directorates of Diyala Provincial and Baghdad. The research sample consisted of (14) supervisors from the Diyala Provincial Department of Education and the First Rusafa Education Directorate in Baghdad Governorate by (8) supervisors and (6) Supervisors respectively specializing in Arabic language. As for the research tool, questionnaire prepared by the researc
... Show MoreIn this article, the lattice Boltzmann method with two relaxation time (TRT) for the D2Q9 model is used to investigate numerical results for 2D flow. The problem is performed to show the dissipation of the kinetic energy rate and its relationship with the enstrophy growth for 2D dipole wall collision. The investigation is carried out for normal collision and oblique incidents at an angle of . We prove the accuracy of moment -based boundary conditions with slip and Navier-Maxwell slip conditions to simulate this flow. These conditions are under the effect of Burnett-order stress conditions that are consistent with the discrete Boltzmann equation. Stable results are found by using this kind of boundary condition where d
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