Preferred Language
Articles
/
4oYXT4YBIXToZYAL2oHr
Proportional-Derivative PD Vibration Control with Adaptive Approximation Compensator for a Nonlinear Smart Thin Beam Interacting with Fluid
...Show More Authors

This work is concerned with the vibration attenuation of a smart beam interacting with fluid using proportional-derivative PD control and adaptive approximation compensator AAC. The role of the AAC is to improve the PD performance by compensating for unmodelled dynamics using the concept of function approximation technique FAT. The key idea is to represent the unknown parameters using the weighting coefficient and basis function matrices/vectors. The weighting coefficient vector is updated using Lyapunov theory. This controller is applied to a flexible beam provided with surface bonded piezo-patches while the vibrating beam system is submerged in a fluid. Two main effects are considered: 1) axial stretching of the vibrating beam that leads to the appearance of cubic stiffness term in beam modelling, and 2) fluid effect. Fluid forces are decomposed into two components: hydrodynamic forces due to the beam oscillations and external (disturbance) hydrodynamic loads independent of beam oscillations. Simulation experiments are implemented using MATLAB/SIMULINK to verify the correctness of the proposed controller. Two piezo-patches are bonded on the beam while an impulse force with multi-pulse is applied to excite the beam vibration. The results show the strength of the proposed control structure.

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Wed Aug 30 2023
Journal Name
Al-kindy College Medical Journal
Factors associated with Exacerbation of Myasthenia Gravis in a Group of Iraqi Patients
...Show More Authors

Background: Myasthenia gravis is an autoimmune disease of the neuromuscular junction that results in fluctuating muscle weakness as well as significant fatigue. Disease exacerbation is a critical condition, and the predisposing factors for it need to be identified to improve preventive measures.

Objectives:  Our study aims to determine the predisposing factors for myasthenia gravis exacerbations in a group of Iraqi patients.

Subjects and Methods: A total number of 30 myasthenia gravis patients were admitted to the hospital with an exacerbation of their symptoms, determined as the development of functional disability, dysphagia, or respiratory fai

... Show More
View Publication Preview PDF
Scopus Crossref
Publication Date
Thu Jan 30 2014
Journal Name
Al-kindy College Medical Journal
Orbital Hydatid Disease: A case study of young patients with primary orbital lesion
...Show More Authors

Background:This is a prospective study of three children presented to us in the Orbital clinic in AL ShahidGazi Al Hariri Hospital with painless proptosiswith suspension of Hydatid disease.Objectives: : Orbital hydatid disease is a rare lesion accounting for less than 1% of the total lesions of the body (1, 2). Orbital cysts presented as a primary lesion in our study which is rare to have such lesion without involvement of other organs (3). Humans represent the intermediate host where the commonly affected organ are liver and the lung (10-15%) (4). Methods:This is a prospective study of three Children presented to us in the Orbital clinic in Al Shahid Ghazi Alhariri Hospital with painless proptosis with suspension of Hydatid disease, dep

... Show More
View Publication Preview PDF
Publication Date
Mon Jul 01 2024
Journal Name
Journal Of Engineering
Design and Implementation of a Microstrip Six-Port Reflectometer (SPR) with Enhanced Bandwidth
...Show More Authors

A compact microstrip six-port reflectometer (SPR) with extended bandwidth is proposed in this paper. The design is based on using 16-dB multi-section coupled line directional couplers and a multi-section 3-dB Wilkinson power divider operating from 1 to 6 GHz. The proposed SPR employs only two calibration standards: a matched load and an open load. As compared to other dielectric substrates, fabricating the proposed SPR involves using a low-cost (FR4) substrate. A novel algorithm is also proposed to estimate the complex reflection coefficient over the frequency ranges at which the standard performance of the circuit components is not fully satisfied. The new algorithm is based on the circles’ intersection points, which have been de

... Show More
View Publication
Crossref
Publication Date
Tue Dec 29 2020
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Personal tax exemptions "a comparative study with some Arab and European system legislations
...Show More Authors

This research aims primarily to highlight personal tax exemptions A comparative study with some Arab and European regulations. And by conducting both theoretical comparative analyses. Most important findings of the study is the need to grant personal and family exemptions that differ according to the civil status of the taxpayer (single or married). In other words, the exemption increases as the number of family members depend on its social sense. Also taking into account some incomes that require a certain effort and looking at the tax rates, it is unreasonable for wages to be subject to the same rates applied to commercial profits.      

View Publication Preview PDF
Publication Date
Mon Feb 01 2010
Journal Name
Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, And Endodontology
Oral Candida flora in a group of Jordanian patients with β-thalassemia major
...Show More Authors

Objective Thalassemic patients present with multiple immune abnormalities that may predispose them to oral Candida, however this has not been investigated. The aim of this study was to assess oral candidal colonization in a group of patients with β-thalassemia major both qualitatively and quantitatively. Study design The oral mycologic flora of 50 β-thalassemia major patients and 50 age- and sex-matched control subjects was assessed using the concentrated oral rinse technique. Candida species were identified using the germ tube test and the Vitek yeast identification system. Results Oral Candida was isolated from 37 patients (74%) and 28 healthy subjects (56%; P = .04). The mean candidal count was significantly higher in thalassemic patie

... Show More
View Publication
Scopus (7)
Crossref (7)
Scopus Clarivate Crossref
Publication Date
Tue Feb 01 2011
Journal Name
Biochemical Engineering Journal
Elicitation of Streptomyces coelicolor with E. coli in a bioreactor enhances undecylprodigiosin production
...Show More Authors

View Publication
Scopus (20)
Crossref (15)
Scopus Clarivate Crossref
Publication Date
Wed Apr 20 2011
Journal Name
Journal Of Al-qadisiyah For Computer Science And Mathematics
Chaos in a harvested prey-predator model with infectious disease in the prey
...Show More Authors

A harvested prey-predator model with infectious disease in preyis investigated. It is assumed that the predator feeds on the infected prey only according to Holling type-II functional response. The existence, uniqueness and boundedness of the solution of the model are investigated. The local stability analysis of the harvested prey-predator model is carried out. The necessary and sufficient conditions for the persistence of the model are also obtained. Finally, the global dynamics of this model is investigated analytically as well as numerically. It is observed that, the model have different types of dynamical behaviors including chaos.

View Publication Preview PDF
Publication Date
Sun Oct 01 2017
Journal Name
Journal Of Mechanical Science And Technology
Optimization of a rectangular pin fin using elliptical perforations with different inclination angles
...Show More Authors

View Publication
Scopus (5)
Crossref (5)
Scopus Clarivate Crossref
Publication Date
Sat Dec 30 2017
Journal Name
International Journal Of Heat And Technology
Optimization of a rectangular pin fin using rectangular perforations with different inclination angles
...Show More Authors

View Publication
Scopus (6)
Crossref (3)
Scopus Crossref
Publication Date
Thu Jan 20 2022
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Strongly Maximal Submodules with A Study of Their Influence on Types of Modules
...Show More Authors

      Let S be a commutative ring with identity, and A is an S-module. This paper introduced an important concept, namely strongly maximal submodule. Some properties and many results were proved as well as the behavior of that concept with its localization was studied and shown.

View Publication Preview PDF
Crossref