Preferred Language
Articles
/
joe-676
Variable Structure Control Design for a Magnetic Levitation System
...Show More Authors

In this paper the variable structure control theory is utilized to derive a discontinuous controller to the magnetic levitation system. The magnetic levitation system model is considered uncertain, which subjected to the uncertainty in system parameters, also it is open-loop unstable and strongly nonlinear. The proposed variable structure control to magnetic levitation system is proved, and the area of attraction is determined. Additionally, the chattering, which induced due to the discontinuity in control law, is attenuated by using a non-smooth approximate. With this approximation the resulted controller is a continuous variable structure controller with a determined steady state error according to the selected control parameters. Finally the ability and the effectiveness of the proposed continuous variable structure controller to the magnetic levitation system are verified via numerical simulations. When state initiated inside the area of attraction, the results show that the ball position can be directed to follow various desired positions, with steady state error not exceeding .  

 

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Wed Jan 18 2012
Journal Name
Journal Of Engineering
Physical Adsorption, Chemical Adsorption, Surface Area, Pore Size distribution, HDS catalyst
...Show More Authors

Physical and chemical adsorption analyses were carried out by nitrogen gas using ASTM apparatus at 77 K and hydrogen gas using volumetric apparatus at room temperature respectively. These analyses were used for determination the effect of coke deposition and poisoning metal on surface area, pore size distribution and metal surface area of fresh and spent hydrodesulphurization catalyst Co-MoAl2O3 .Samples of catalyst (fresh and spent) used in this study are taken from AL-Dura refinery. The results of physical adsorption shows that surface area of spent catalyst reduced to third compare with fresh catalyst and these catalysts exhibit behavior of type four according to BET classification ,so, the pores of these samples are cylindrical, and the

... Show More
Preview PDF
Publication Date
Tue Jan 31 2012
Journal Name
Journal Of Engineering
Adsorption Study of Hydrodesulphurization Catalyst
...Show More Authors

Physical and chemical adsorption analyses were carried out by nitrogen gas using ASTM apparatus at 77 K and hydrogen gas using volumetric apparatus at room temperature, respectively. These analyses were used to determine the effect of coke deposition and poisoning metal on surface area, pore size distribution, and metal surface area of fresh and spent hydrodesulphurization catalyst Co-Mo\Al2O3 . Samples of catalyst (fresh and spent) used in this study are taken from AL-Dura refinery. The results of physical adsorption shows that surface area of spent catalyst reduced to third compare with fresh catalyst and these catalysts exhibit behavior of type four according to BET classification ,so, the pores of these samples are cylindrical, an

... Show More
View Publication Preview PDF
Publication Date
Wed May 10 2023
Journal Name
Journal Of Engineering
ADSORPTION STUDY OF HYDRODESULPHURIZATION CATALYST
...Show More Authors

Physical and chemical adsorption analyses were carried out by nitrogen gas using ASTM apparatus at 77 K
and hydrogen gas using volumetric apparatus at room temperature respectively. These analyses were used for
determination the effect of coke deposition and poisoning metal on surface area, pore size distribution and
metal surface area of fresh and spent hydrodesulphurization catalyst Co-Mo\Al2O3 .
Samples of catalyst (fresh and spent) used in this study are taken from AL-Dura refinery.
The results of physical adsorption shows that surface area of spent catalyst reduced to third compare with
fresh catalyst and these catalysts exhibit behavior of type four according to BET classification ,so, the pores
of these sample

... Show More
View Publication Preview PDF
Crossref
Publication Date
Fri Dec 01 2023
Journal Name
Baghdad Science Journal
Estimating the chemical composition of secondary compounds of Iraqi wild Agaricus bellaniae characterized morphologically and genetically
...Show More Authors

   This study, which is considered the first of its kind in the world and the Arab homeland, was carried out in the laboratory of mushroom production belonging to the Medicinal Plant Unit/ College Of Agricultural Engineering Sciences/ University of  Baghdad during the period from July 21, 2016, to December 30, 2018, aiming to isolate and purify the mycelium of the wild isolation in addition to the genetic and morphological identification of the mushroom Agaricus bellaniae. The obtained pure isolation was tagged in the American National Center for Biotechnology Information (NCBI) with symbol MF987843.1, thus Iraq would be the second country in the world in which the mushroom is grown following the United States of America. The

... Show More
View Publication Preview PDF
Scopus Crossref
Publication Date
Thu Oct 01 2020
Journal Name
Iraqi Journal Of Applied Physics
Spectral and Electrical Characteristics of Nanostructured NiO/TiO 2 Heterojunction Fabricated by DC Reactive Magnetron Sputtering
...Show More Authors

In this work, p-n junctions were fabricated from highly-pure nanostructured NiO and TiO2 thin films deposited on glass substrates by dc reactive magnetron sputtering technique. The structural characterization showed that the prepared multilayer NiO/TiO2 thin film structures were highly pure as no traces for other compounds than NiO and TiO2 were observed. It was found that the absorption of NiO-on-TiO2 structure is higher than that of the TiO2-on-NiO. Also, the NiO/TiO2 heterojunctions exhibit typical electrical characteristics, higher ideality factor and better spectral responsivity when compared to those fabricated from the same materials by the same technique and with larger particle size and lower structural purity.

View Publication Preview PDF
Publication Date
Thu Feb 01 2024
Journal Name
Baghdad Science Journal
Forgotten Index and Forgotten Coindex of Graphs
...Show More Authors

F index is a connected graph, sum of the cubes of the vertex degrees. The forgotten topological index has been designed to be employed in the examination of drug molecular structures, which is extremely useful for pharmaceutical and medical experts in understanding the biological activities. Among all the topological indices, the forgotten index is based on degree connectivity on bonds. This paper characterized the forgotten index of union of graphs, join graphs, limits on trees and its complements, and accuracy is measured. Co-index values are analyzed for the various molecular structure of chemical compounds

View Publication Preview PDF
Scopus (4)
Crossref (1)
Scopus Crossref
Publication Date
Fri Apr 30 2021
Journal Name
Al-kindy College Medical Journal
The Role of MRI-US Fusion Techniques in Detection of Clinically Significant Prostate Cancer
...Show More Authors

Prostate cancer is the commonest male cancer and the second leading cause of cancer-related death in men. Over many decades, prostate cancer detection represented a continuous challenge to urologists. Although all urologists and pathologists agree that tissue diagnosis is essential especially before commencing active surgical or radiation treatment, the best way to obtain the biopsy was always the big hurdle. The heterogenicity of the tumor pathology is very well seen in its radiological appearance. Ultrasound has been proven to be of limited sensitivity and specificity in detecting prostate cancer. However, it was the only available targeting technique for years and was used to guide biopsy needle passed transrectally or transperineally

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Jun 30 2015
Journal Name
Al-khwarizmi Engineering Journal
Laser Peening on Aluminum Alloy 7049 Using Black Paint Surface Coating
...Show More Authors

Abstract

Black paint laser peening (bPLP) technique is currently applied for many engineering materials , especially for aluminum alloys due to high improvement in fatigue life and strength . Constant and variable   bending fatigue tests have been performed at RT and stress ratio R= -1 . The results of the present  work observed that the significance of the surface work hardening which generated high negative residual stresses in bPLP specimens .The fatigue life  improvement factor (FLIF)  for bPLP constant fatigue behavior was from 2.543 to 3.3 compared to untreated  fatigue and the increase in fatigue strength at 107 cycle was 21% . The bPLP cumulative fatigue life behav

... Show More
View Publication Preview PDF
Publication Date
Fri Jul 01 2016
Journal Name
Journal Of Economics And Administrative Sciences
مقارنة بعض الطرائق الجزائية في تحليل انموذج المؤشر الواحد شبه المعلمي مع تطبيق عملي
...Show More Authors

ABSTRACT

In this research been to use some of the semi-parametric methods the based on the different function penalty as well as the methods proposed by the researcher  because these methods work to estimate and variable selection of significant at once for single index model including (SCAD-NPLS method , the first proposal SCAD-MAVE method , the second proposal  ALASSO-MAVE method ) .As it has been using a method simulation time to compare between the semi-parametric estimation method studied , and various simulation experiments to identify the best method based on the comparison criteria (mean squares error(MSE) and average  mean squares error (AMSE)).

And the use

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Jul 01 2019
Journal Name
Journal Of Engineering
Speed Controller of Three Phase Induction Motor Using Sliding Mode Controller
...Show More Authors

In this paper, an adaptive integral Sliding Mode Control (SMC) is employed to control the speed of Three-Phase Induction Motor. The strategy used is the field oriented control as ac drive system. The SMC is used to estimate the frequency that required to generates three phase voltage of Space Vector Pulse Width Modulation (SVPWM) invertor . When the SMC is used with current controller, the quadratic component of stator current is estimated by the controller. Instead of using current controller, this paper proposed estimating the frequency of stator voltage since that the slip speed is function of the quadratic current . The simulation results of using the SMC showed that a good dynamic response can be obtained under load

... Show More
View Publication Preview PDF
Crossref (1)
Crossref