Preferred Language
Articles
/
dIYwNYYBIXToZYALqH8F
Optimal insulation design of form-wound stator winding with stress grading system under fast rise-time excitation
...Show More Authors

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.

Crossref
Publication Date
Mon Oct 01 2018
Journal Name
Iraqi Journal Of Physics
Study of matter density distributions, elastic charge form factors and size radii for halo 11Be, 19C and 11Li nuclei
...Show More Authors

In this work, the calculation of matter density distributions, elastic charge form factors and size radii for halo 11Be, 19C and 11Li nuclei are calculated. Each nuclide under study are divided into two parts; one for core part and the second for halo part. The core part are studied using harmonic-oscillator radial wave functions, while the halo part are studied using the radial wave functions of Woods-Saxon potential. A very good agreement are obtained with experimental data for matter density distributions and available size radii. Besides, the quadrupole moment for 11Li are generated.

View Publication Preview PDF
Crossref (3)
Crossref
Publication Date
Mon May 28 2018
Journal Name
Iraqi Journal Of Science
Theoretical Study of Nuclear Density Distributions and Elastic Electron Scattering Form Factors of Some Proton Halo Nuclei (17Ne and 8B)
...Show More Authors

     Theoretical investigation of proton halo-nucleus (8B and 17Ne) has revealed that the valence protons are to be in pure (1p1/2)1 orbit for 8B and (1d3/2)2 orbit for 17Ne.  The nuclear matter density distributions, the elastic electron scattering form factors and (proton, charge, neutron and matter) root-mean square (rms) are studied for our tested nuclei, through an effective two-body density operator for point nucleon system folded with two-body full correlation operator's functions. The full correlation (FC's ) takes account of the effect for the strong short range repulsion (SRC's) and the strong tensor force (TC's) in

... Show More
View Publication Preview PDF
Publication Date
Sun Jul 02 2023
Journal Name
Iraqi Journal Of Science
Study of Density Distributions, Elastic Electron Scattering form factors and reaction cross sections of 9C, 12N and 23Al exotic nuclei
...Show More Authors

The ground state densities of unstable proton-rich 9C, 12N and 23Al exotic nuclei are studied via the framework of the two-frequency shell model (TFSM) and the binary cluster model (BCM). In TFSM, the single particle harmonic oscillator wave functions are used with two different oscillator size parameters βc and βv, where the former is for the core (inner) orbits and the latter is for the valence (halo) orbits. In BCM, the internal densities of the clusters are described by single particle Gaussian wave functions. The long tail performance is clearly noticed in the calculated proton and matter density distributions of these nuclei. The structure of the valence proton in 9C and 12N is a pure (1p1/2) configuration while that for 23Al is

... Show More
View Publication Preview PDF
Publication Date
Sun Oct 22 2023
Journal Name
Iraqi Journal Of Science
Study of Matter Density Distributions, Elastic Electron Scattering form Factors and Reaction Cross Sections of 8He And 17B Exotic Nuclei
...Show More Authors

The ground state densities of unstable neutron-rich 8He and 17B exotic nuclei are studied via the framework of the two-frequency shell model (TFSM) and the binary cluster model (BCM). In TFSM, the single particle harmonic oscillator wave functions are used with two different oscillator size parameters βc and βv where the former is for the core (inner) orbits and the latter is for the valence (halo) orbits. In BCM, the internal densities of the clusters are described by single particle Gaussian wave functions. Shell model calculations for the two valence neutrons in 8He and 17B are performed via the computer code OXBASH. The long tail performance is clearly noticed in the calculated neutron and matter density distributions of these nucl

... Show More
View Publication Preview PDF
Publication Date
Mon Mar 07 2022
Journal Name
Journal Of Educational And Psychological Researches
The Level of Administrative Work Quality of Private Schools Principals at Southern Governorates of Palestine form the Teachers Point of View
...Show More Authors

The study aimed at identifying the level of administrative work quality of private Schools principals at Southern Governorates of Palestine from the teachers' point of view in their schools. To achieve the objectives of this research, a questionnaire was prepared by the researcher consisted of (28) items. It was applied to a sample of (350) teachers. The researcher adopted the descriptive-analytical approach. The results of the study showed that the degree to which principals of private schools in the southern governorates of Palestine practice Administrative Work Quality from the viewpoint of their teachers was very high, with relative weight (85.00%). The results also showed that there are statistically significant differences at the l

... Show More
View Publication Preview PDF
Publication Date
Fri Feb 07 2025
Journal Name
Journal Of Baghdad College Of Dentistry
Histological and mechanical evaluation of the osseointegration of titanium implants by the modifications of thread design and/or coating with flaxseed (An experimental study on rabbits)
...Show More Authors

Background: Dental implant surface technologies have been evolving rapidly to enhance a more rapid bone formation on their surface and improve implant therapy.Implant threads should be designed to increase surface contact areathat induced better stability. In addition, implant surface coating with Flaxseed was used to enhance bone formation at the bone-implant interface. Materials and methods: Ninety-six commercially pure titanium (CpTi) screws were implanted in rabbits' tibiae and divided into three groups as dual-threaded group, flaxseed-coated group and control group. All groups were evaluated mechanically, histologically and radiographically after each healing periods (2, 4, 6 and 8) weeks and the resulting data were statistically analy

... Show More
View Publication Preview PDF
Publication Date
Wed Jan 19 2022
Journal Name
Iraqi Journal Of Science
Determination of Some Oxidative Stress Parameters and Antioxidants in Sample of Iraqi Beta Thalassemia Major Patients
...Show More Authors

Repeated blood transfusion in beta thalassemia major patients may lead to peroxidative tissue injury by secondary iron overload. In the present study, 100 patients(50 male+50 female) with beta thalassemia major patients with age (5-20) years and 60 healthy control were included during their attendance at Abin Al_Baladi hospital in Baghdad. Malondialdehyde ,Superoxide Dismutase and Vitamin E, were measured by using kits.The results showed A highly significant (p<0.01)increase in the levels of Malondialdehyde and Superoxide Dismutase, whereas, significant p(<0.01)decrease in the levels of vitamin-E, This suggest that oxidative stress and reduced antioxidant defense mechanism play an important role in pathogenesis of beta thalassemia

... Show More
View Publication Preview PDF
Publication Date
Sat Nov 10 2018
Journal Name
Iraqi National Journal Of Nursing Specialties
Sources of Work-Related Stress among Nurses Working at Psychiatric Wards in Hospitals of Baghdad City
...Show More Authors

Objectives: The study intends to identify the sources of work-related stress that might face the nurses working at
psychiatric wards in Baghdad psychiatric hospitals and to find out a relationship between the levels of stress and
some demographic characteristics.
Methodology: A descriptive study was achieved from the 10th of December, 2013 through the 10th of March, 2014.
Non-probability purposive samples of 94 nurses who work in psychiatric wards of Baghdad psychiatric hospitals
were recruited to meet the study objectives. Psychological Stress Inventory (PSI) the Arabic version, which was
modified by Abu Al-Hussein (2010) (20), was used. Data were analyzed by using the statistical analysis program of
SPSS 19th versi

... Show More
View Publication Preview PDF
Publication Date
Thu Dec 26 2019
Journal Name
Bulletin Of The Iraq Natural History Museum (p-issn: 1017-8678 , E-issn: 2311-9799)
THE EFFECTS OF TEMPERATURE AND MOISTURE STRESS CONTENT ON THE EXTENSIVE CULTIVATION OF THE OYSTER MUSHROOM
...Show More Authors

    Oyster mushroom (Pleurotus ostreatus (Jacq. ex Fr.) P. Kumm.) is involved in the destruction of dead wood which is the main place of settlement of several living organisms. After humification, dead wood also becomes an important component of forest soils.

 

    The purpose of the research is to study temperature and moisture conditions of extensive cultivation of oyster mushrooms on various wood substrates. To accomplish this goal, the following tasks were set: to determine the amount of effective stress temperatures and moisture content of substrates and their influence on the appearance of fruiting bodies of the oyster mushroom; to study the features of the extensive culti

... Show More
View Publication Preview PDF
Scopus (1)
Crossref (3)
Scopus Crossref
Publication Date
Mon Jun 08 1998
Journal Name
Journal Of King Saud University
Moment Capacity and Strength of Reinforced Concrete Members Using Stress- Strain Diagrams of Concrete and Steel
...Show More Authors