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Variable Structure Control Design for a Magnetic Levitation System
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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 .  

 

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Publication Date
Mon Dec 01 2014
Journal Name
Photonic Sensors
Crystalline Structure and Surface Morphology of Tin Oxide Films Grown by DC Reactive Sputtering
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Abstract: Tin oxide thin films were deposited by direct current (DC) reactive sputtering at gas pressures of 0.015 mbar – 0.15 mbar. The crystalline structure and surface morphology of the prepared SnO2 films were introduced by X-ray diffraction (XRD) and atomic force microscopy (AFM). These films showed preferred orientation in the (110) plane. Due to AFM micrographs, the grain size increased non-uniformly as the working gas pressure increased.

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Publication Date
Mon Jun 27 2022
Journal Name
. J Pharm Negative Results
Synthesis, Antioxidant, antibacterial and docking structure of new dihydro-pyrimidine derivatives containing multi phenol
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Newly series of 6,6’-((2-(Aryl)dihydropyrimidine-1,3(2H,4H)-diyl)bis(methylene))bis(2-methoxy phenol) (3a-i) were synthesized from cyclization of 6,6’-((propane-1,3-diylbis (azanediyl)) bis(methylene)) bis(2-methoxyphenol) with several aryl aldehyde in the presence of acetic acid. The newly compounds characterized from their IR, NMR and EIMs spectra. The antioxidant capacity of these compounds screened by utilizing DPPH and FRAP assays. Compounds 3g and 3i exhibited significant antioxidant capability in both assays. Docking study for these compounds as a potential inhibitors of gyrase enzyme were carried out. Compound 3g exhibited significant inhibition with binding free energies (DG) higher than novobiocin. compounds 2, 3a, 3b, 3

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Publication Date
Sun Dec 15 2019
Journal Name
Al-academy
The Dominating Sign of the Space Structure in TV Drama: صادق كاظم عبد علي
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  The space constitutes a cornerstone of the creativity process since the emergence of arts and literature. Gaston Bachelard has a significant role in highlighting the importance of the place in his book entitled (Poetics of Space). Since then, the space, especially in the TV drama, is no longer a mere background indicating the location or the date of the event. Space inside these series has become an inseparable part of the artistic or dramatic fabric, that the visual scene started to formulate alongside the movement of the individuals in their language or accents that are specified inside the space as an incubator for the décor, clothes, makeup, accessories and lights in addition to the sound and musical effects. The lens angles

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Publication Date
Thu Mar 01 2012
Journal Name
Journal Of Economics And Administrative Sciences
The Impact of Intellectual trends on the nature of the Economic Structure of Iraq
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The Impact of Intellectual trends on the nature of the Economic Structure of Iraq

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Publication Date
Tue Jan 08 2019
Journal Name
Iraqi Journal Of Physics
Effect of thickness on the structure, morphology and A.C conductivity of Bi2S3 thin films
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Thin films samples of Bismuth sulfide Bi2S3 had deposited on
glass substrate using thermal evaporation method by chemical
method under vacuum of 10-5 Toor. XRD and AFM were used to
check the structure and morphology of the Bi2S3 thin films. The
results showed that the films with law thickness <700 nm were free
from any diffraction peaks refer to amorphous structure while films
with thickness≥700 nm was polycrystalline. The roughness decreases
while average grain size increases with the increase of thickness. The
A.C conductivity as function of frequency had studied in the
frequency range (50 to 5x106 Hz). The dielectric constant,
polarizability showed significant dependence upon the variation of
thic

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Publication Date
Sun Feb 10 2019
Journal Name
Iraqi Journal Of Physics
Nuclear structure study of some tin isotopes using the self-consistent mean field method
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Hartree-Fock calculations for even-even Tin isotopes using
Skyrme density dependent effective nucleon-nucleon interaction are
discussed systematically. Skyrme interaction and the general formula
for the mean energy of a spherical nucleus are described. The charge
and matter densities with their corresponding rms radii and the
nuclear skin for Sn isotopes are studied and compared with the
experimental data. The potential energy curves obtained with
inclusion of the pairing force between the like nucleons in Hartree-
Fock-Bogoliubov approach are also discussed.

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Publication Date
Wed Apr 01 2020
Journal Name
Aajps
Morphological description and histological structure of Gallbladder in local adult chicken Gallus gallus domesticus
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The present study aimed to investigate the morphological description and histological structure of Gallbladder in the adult local chicken bird. The morphological description and histological structure of the Gallbladder in the local chicken Gallus gallus domesticus found in the form of a cystic, spindle or pear-shaped, dark green color, located within the visceral abdominal side of the right lobe of the liver, histologically it was found that its wall consisted of three tunicae. The first tunica is mucosa which consists of an epithelial lining layer and lamina propria layer, while the muscularis mucosa was missing. The second tunica is musclaris, which is composed of smooth circularly arranged muscle fibers, and the third tunica is serosa o

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Publication Date
Sun Jun 05 2016
Journal Name
Baghdad Science Journal
Density functional theory study of molecular structure, Electronic properties, UV–Vis spectra on coumarin102.
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The various properties of the ground and excited electronic states of coumarins 102 using density functional theory (DFT) and time-dependent density functional theory (TDDFT) was calculated by the B3LYP density functional model with 6-31G(d,p) basis set by Gaussian 09 W program. Spectral characteristics of coumarin102 have been probed into by methods of experimental UV-visible, and quantum chemistry. The UV spectrum was measured in methanol. The optimized structures, total energies, electronic states (HOMO- LUMO), energy gap, ionization potentials, electron affinities, chemical potential, global hardness, softness, global electrophilictity, and dipole moment were measured. We find good agreement between experimental data of UV spectrum and

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Publication Date
Tue Dec 11 2018
Journal Name
Iraqi Journal Of Physics
Preparation and study the structure of pure and impure barium titanate with Mg2+ ion
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Pure and doped barium titanate with Mg2+ ion at two molar ratios x= (5%, 10%) mol. has been synthesized by solid state reaction technique. The powders sintered at two temperatures (1000 °C and 1400 °C). An XRD technique was used in order to study the crystal structure of pure and doped barium titanate, which confirmed the formation of the tetragonal phase of BaTiO3, and then calculate the lattice parameters of pure and doped barium titanate, the addition of magnesium ion Mg2+ can lead to decreases lattice parameters.

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Publication Date
Wed Feb 01 2023
Journal Name
Baghdad Science Journal
Study the Nuclear Structure of Some Even-Even Ca Isotopes Using the Microscopic Theory
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The root-mean square-radius of proton, neutron, matter and charge radii, energy level, inelastic longitudinal form factors, reduced transition probability from the ground state to first-excited 2+ state of even-even isotopes, quadrupole moments, quadrupole deformation parameter, and the occupation numbers for some calcium isotopes for A=42,44,46,48,50 are computed using fp-model space and FPBM interaction. 40Ca nucleus is regarded as the inert core for all isotopes under this model space with valence nucleons are moving throughout the fp-shell model space involving 1f7/2, 2p3/2, 1f5/2, and 2p1/2 orbits. Model space is used to present calculations using FPBM intera

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