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.
Tuberculosis status as the second leading causes of significant morbidity and mortality from an infectious disease worldwide, after human immunodeficiency virus (HIV). Sample collection was conducted at the Institute of Chest and Respiratory Diseases/Baghdad Medical City in Baghdad. The collection interval was from August to October 2014, 629 suspected TB patients were examined during this period. The results revealed among total 629 specimens, 56 (8.9%) of the specimens were positive by direct examination and 573 (91.1%) negative specimens by smear microscopy. Fifty six DNA samples were extracted from positive ZN smears of sputum specimens and 40 samples from healthy persons (as control) were subjected to molecular diagnosis by real tim
... Show MoreThe goal of this paper is to expose a new numerical method for solving initial value time-lag of delay differential equations by employing a high order improving formula of Euler method known as third order Euler method. Stability condition is discussed in detail for the proposed technique. Finally some examples are illustrated to verify the validity, efficiency and accuracy of the method.
In this work 27 events have been chosen for the period from (17 Feb 2000 to 10 Sep 2014) to analyze their intensity profile and find out what is the most effective reason behind the bulk of the accelerated SEPs as seen in the interval from the onset to the maximum intensity. It was found that the parameters of the associated eruptions (CME and solar flare) could play a major role in this acceleration. We considered some of these parameters such as: flare class related to soft X-ray flux, CME's speed and acceleration, site of the eruption (western, eastern) and particle transport in the IP medium. The shape of the profile showed a clear changing in ΔT1 (time from onset to maximum), as an inverse relation with the acceleration of coronal
... Show MoreThis paper is concerned with finding solutions to free-boundary inverse coefficient problems. Mathematically, we handle a one-dimensional non-homogeneous heat equation subject to initial and boundary conditions as well as non-localized integral observations of zeroth and first-order heat momentum. The direct problem is solved for the temperature distribution and the non-localized integral measurements using the Crank–Nicolson finite difference method. The inverse problem is solved by simultaneously finding the temperature distribution, the time-dependent free-boundary function indicating the location of the moving interface, and the time-wise thermal diffusivity or advection velocities. We reformulate the inverse problem as a non-
... Show MoreThe aim of this research is to recognize the tasks undertaken by the headmasters of intermediate schools concerning time- administration, in accordance to the viewpoints of the headmasters of intermediate schools in the Administration of Education of Al-Karkh the Third. The sample of this research consists of (60) headmasters and &n
... Show MoreIn this paper, a numerical approximation for a time fractional one-dimensional bioheat equation (transfer paradigm) of temperature distribution in tissues is introduced. It deals with the Caputo fractional derivative with order for time fractional derivative and new mixed nonpolynomial spline for second order of space derivative. We also analyzed the convergence and stability by employing Von Neumann method for the present scheme.
The ground state proton momentum distributions (PMD) and elastic charge form
factors for some odd 1f 2p shell nuclei, such as , , 59 63Co Cu and Cu 65 have been
studied using the Coherent Density Fluctuation Model and formulated by means of
the fluctuation function (weight function) ( ) .
2
f x The fluctuation function has been
connected to the charge density distribution of the nuclei and determined from the
theory and experiment result. The feature of the long-tail behavior at high
momentum region of the PMD has been calculated by both the theoretical and
experimental fluctuation functions. It is found that the inclusion of the quadrupole
form factors ( ) 2 F q C in all nuclei under study, which are de
Inelastic longitudinal electron scattering C2 form factor in 48Ca has been utilized
to study the effects of fitting parameters on the sigma meson exchange type
potentials as a residual interaction. By coupling the core particles with model space
particle, where the latter used as an active part of residual interaction in the so called
core polarization process, it is included as a correction with first order perturbation
theory to the main calculation of model space, and the excitation energy has been
carried out with ( ). A model space wave vectors are generated in full fp shell
model with FPD6 as effective interaction with mixing configuration technique and
harmonic oscillator as a single particle wave function.
The wave functions of the coherent states of the charged oscillator in magnetic field are obtained via a canonical transformation. The numerical calculations of these functions are made and then the space and time plots are obtained. It was shown that these states are Gaussians distributions of widths vary periodically in an opposite way with their peaks. We interpret that is due to the mutual actions of the spreading effect of the wave packet and the reaction of the magnetic field.
Agile methodologies are adopted extensively by many of the software industries as it is flexible in nature as well as can address the required changes in any phase of development. Authentic estimation of the software products is not an easy task as it requires continuous attention of the product owner. Effort and cost can be estimated in a proper manner to ensure the success of the project. In this article, we considered the Scrum-based Agile projects that are developed into several Sprints. We proposed an extension to an existing algorithm, based on a total of 36 success factors; that estimate the development cost and effort required to complete the project. For estimation and computations, we have taken a dataset of 12 project
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