Preferred Language
Articles
/
ThZoB4cBVTCNdQwCljDI
Design of an adaptive state feedback controller for a magnetic levitation system
...Show More Authors

This paper presents designing an adaptive state feedback controller (ASFC) for a magnetic levitation system (MLS), which is an unstable system and has high nonlinearity and represents a challenging control problem. First, a nonadaptive state feedback controller (SFC) is designed by linearization about a selected equilibrium point and designing a SFC by pole-placement method to achieve maximum overshoot of 1.5% and settling time of 1s (5% criterion). When the operating point changes, the designed controller can no longer achieve the design specifications, since it is designed based on a linearization about a different operating point. This gives rise to utilizing the adaptive control scheme to parameterize the state feedback controller in terms of the operating point. The results of the simulation show that the operating point has significant effect on the performance of nonadaptive SFC, and this performance may degrade as the operating point deviates from the equilibrium point, while the ASFC achieves the required design specification for any operating point and outperforms the state feedback controller from this point of view.

Scopus Crossref
View Publication
Publication Date
Fri Aug 31 2012
Journal Name
Al-khwarizmi Engineering Journal
Natural Convection Heat Transfer in an Inclined Open-Ended Square Cavity with Partially Active Side Wall
...Show More Authors

This paper reports a numerical study of flow behaviors and natural convection heat transfer characteristics in an inclined open-ended square cavity filled with air. The cavity is formed by adiabatic top and bottom walls and partially heated vertical wall facing the opening. Governing equations in vorticity-stream function form are discretized via finite-difference method and are solved numerically by iterative successive under relaxation (SUR) technique. A computer program to solve mathematical model has been developed and written as a code for MATLAB software. Results in the form of streamlines, isotherms, and average Nusselt number, are obtained for a wide range of Rayleigh numbers 103-106 with Prandtl number 0.71

... Show More
View Publication Preview PDF
Publication Date
Sat Feb 12 2022
Journal Name
Engineering, Technology & Applied Science Research
Prestressing Effects on Full Scale Deep Beams with Large Web Openings¨: An Experimental and Numerical Study
...Show More Authors

Most studies on deep beams have been made with reinforced concrete deep beams, only a few studies investigate the response of prestressed deep beams, while, to the best of our knowledge, there is not a study that investigates the response of full scale (T-section) prestressed deep beams with large web openings. An experimental and numerical study was conducted in order to investigate the shear strength of ordinary reinforced and partially prestressed full scale (T-section) deep beams that contain large web openings in order to investigate the prestressing existence effects on the deep beam responses and to better understand the effects of prestressing locations and opening depth to beam depth ratio on the deep beam performance and b

... Show More
View Publication
Scopus (2)
Crossref (2)
Scopus Crossref
Publication Date
Fri Oct 30 2020
Journal Name
Journal Of Economics And Administrative Sciences
Reflection the organizational Ambidexterity on organizational excellence An exploratory study at the Iraqi Cotton Industries Company
...Show More Authors

Organizations of various activities strive to excel and continue in light of the challenges they face, so they seek to have leaders and workers in them for the ingenuity that is reflected in their excellence in work and achievement that is achieved through the adoption of the best modern technological technologies to reach Organizations to the best levels and thus achieve their goals easily and successfully.  The research aims are to know the correlation and impact between organizational proficiency and the dimensions of Organizations excellence (leadership excellence, and distinguish subordinates and excellence in organizational structure) at the Cotton Industries Company through the adoption of a unit of measurement which

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sat Jul 22 2023
Journal Name
Journal Of Engineering
Experimental Investigation into the Heat and Mass Transfer in an Indirect Contact Closed Circuit Cooling Tower
...Show More Authors

The heat and mass transfer coefficients of the indirect contact closed circuit cooling tower, ICCCCT, were investigated experimentally. Different experiments were conducted involving the controlling parameters such as air velocity, spray water to air mass flow rate ratio, spray water flow rate, ambient air wet bulb temperature and the provided heat load to investigate their effects on the performance of the ICCCCT. Also the effect of using packing on the performance of the ICCCCT was investigated. It was noticed that these parameters affect the tower performance and the use of packing materials is a good approach to enhance the performance for different operational conditions. Correlations for mass and heat transfer coefficients are pres

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Mar 15 2020
Journal Name
Al-academy
Shapes as an Alternative to the Word in Designing Textbooks: سحر علي سرحان-منى محمد غلام
...Show More Authors

Shapes have differed in terms of their temporality, tools, technical variations, aesthetic functions and dimensions. The beginnings started with manual primitive techniques that have played an a significant artistic role in the ancient civilizations, then developed with the technological development and the digital technologies that encompassed various programs and specialist means in the graphic design, so that its visual outputs in the textbook that is considered a communication means that has an effect and attracts the recipient. That is what made the researcher search and investigate this topic describing the research problem as follows: What are the shapes as alternatives to the words in the design of the textbook? The research obje

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Mar 05 2024
Journal Name
Scientific Reports
Mesoporous Ag@WO3 core–shell, an investigation at different concentrated environment employing laser ablation in liquid
...Show More Authors
Abstract<p>In this study, silver-tungsten oxide core–shell nanoparticles (Ag–WO<sub>3</sub> NPs) were synthesized by pulsed laser ablation in liquid employing a (1.06 µm) Q-switched Nd:YAG laser, at different Ag colloidal concentration environment (different core concentration). The produced Ag–WO<sub>3</sub> core–shell NPs were subjected to characterization using UV–visible spectrophotometry, X-ray diffraction (XRD), transmission electron microscopy (TEM), energy-dispersive spectroscopy, electrical analysis, and photoluminescence PL. The UV–visible spectra exhibited distinct absorption peaks at around 200 and 405 nm, which attributed to the occurrence of surface Plasmon reson</p> ... Show More
View Publication
Scopus (19)
Crossref (21)
Scopus Clarivate Crossref
Publication Date
Tue Oct 01 2019
Journal Name
Comparative Immunology, Microbiology And Infectious Diseases
Zataria Multiflora bois as an auspicious therapeutic approach against Echinococcus granulosus: Current status and future perspectives
...Show More Authors

View Publication
Scopus (10)
Crossref (6)
Scopus Clarivate Crossref
Publication Date
Thu Jun 15 2017
Journal Name
Journal Of Baghdad College Of Dentistry
Effects of Two Different Colorant Solutions on the Color Stability of Bleached Enamel in Association with CPP-ACPF: An In Vitro Study
...Show More Authors

Background: One of the drawbacks of vital teeth bleaching is color stability. The aim of the present study was to evaluate the effects of tea and tomato sauce on the color stability of bleached enamel in association with the application of MI Paste Plus (CPP-ACPF). Materials and Methods: Sixty enamel samples were bleached with 10% carbamide peroxide for two weeks then divided into three groups (A, B and C) of 20 samples each. After bleaching, the samples of each group were subdivided into two subgroups (n=10). While subgroups A1, B1 and C1 were kept in distilled water, A2, B2, and C2 were treated with MI Paste Plus. Then, the samples were immersed in different solutions as follow: A1 and A2 in distilled water (control); B1 and B2 in black

... Show More
View Publication Preview PDF
Crossref
Publication Date
Fri Feb 01 2019
Journal Name
Journal Of Economics And Administrative Sciences
Determines the application of smart tourism as an electronic commerce application in the form of B2C) to attract tourists to Saudi Arabia
...Show More Authors

Abstract:

The study focused on the application of smart tourism as one of the applications of electronic commerce in the form of (B2C) to attract tourists to Saudi Arabia, where the tourism sector is one of the important sectors on which the Kingdom depends on the diversity of its economy.

The purpose of the research: With the issuance of tourist visas for the first time the study noted a deterioration in the case of Saudi tourist sites over the Internet, which do not live up to this great interest by the Saudi government for this sector, which became vital to them. The study tried to identify the reality of the Saudi tourist sites through the Internet in order to identify the sui

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Feb 26 2026
Journal Name
Journal Of Baghdad College Of Dentistry
The Effect of Acidity Level on Ions Released and Corrosion of Metal Orthodontic Appliances at Different Time Intervals (An In vitro Study)
...Show More Authors

ABSTRACT Background: This study measured the effects of three parameters pH value, length of immersion and type of archwire on metal ions released from orthodontic appliances. Materials and Methods: Ninety maxillary halves simulated fixed orthodontic appliances that were immersed in artificial saliva of different pH values (6.75, 5 and 3.5) during 28 day period. Three types of archwires were used: stainless steel, nickel titanium and thermal activated nickel titanium. The quantity of nickel and chromium ions was determined with the use of atomic force spectrophotometer while iron ions by spectrophotometer. Each orthodontic set was weighted two times, before the ligation and immersion in the artificial saliva and after 28 days at the end of

... Show More
View Publication Preview PDF