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Sliding Mode Vibration Suppression Control Design for a Smart Beam
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Active vibration control is the main problem in different structure. Smart material like piezoelectric make a structure smart, adaptive and self-controlling so, they are effective in active vibration control. In this paper piezoelectric elements are used as sensors and actuators in flexible structures for sensing and actuating purposes, and to control the vibration of a cantilever beam by using sliding mode control. The sliding mode controller (SMC) is designed to attenuate the vibration induced by initial tip displacement which is equal to 15 mm.  It is designed based on the balance realization reduction method where three states are selected for the reduced model from the 24th states that describe the cantilever beam according to the FEM. These states are most controllable and observable. The stability and control performance for the proposed SMC are proved using candidate Lyapunov function and the equivalent control concept. The control spillover, which is the sources of instability, is completely avoided as ensured within the control performance proof.

            Numerical simulations are preformed to test the vibration attenuation ability of the proposed SMC. For 15 mm initial tip displacement, the piezoelectric actuator was found able to reduce the tip displacement to about (0.2) mm within (2.5 s), while it is equal to (3.5) mm with the open loop case. Moreover, the induced chattering in system response, due to the discontinuous control action, is removed by approximating the signum function by a continuous arctan function. As a result  a smoother response are obtained with the same control performance as can be shown in the sliding variable, the control input voltage and the tip displacement plots.

 

 

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Publication Date
Mon Jul 15 2024
Journal Name
Wisdom Journal For Studies & Research
The effect of rehabilitative exercises according to some kinematic variables in relieving lower back pain for women aged 25-35 old
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Abstract The purpose of this paper is preparing exercises according to some biomechanical variables for women with low back pain and identifying the effect of exercise according to some biomechanical variables and relieving lower back pain for women. The researchers used the one-group experimental design. The sample was chosen by the intentional method to provide the necessary conditions for conducting the study, and they represent the research community and its sample. The researchers also excluded (2) of the injured women because they did not adhere to the rehabilitation sessions, and for the purpose of ensuring the homogeneity of the sample members, the researchers used the arithmetic mean, standard deviation, and the torsion coefficient

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Publication Date
Wed Aug 01 2018
Journal Name
International Journal Of Electrochemical Science
Utilization of Natural Dyes from Zingiber officinale Leaves and Clitoria ternatea Flowers to Prepare New Photosensitisers for Dye-Sensitised Solar Cells
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Publication Date
Sat Feb 18 2023
Journal Name
Luminescence
Online column preconcentration for speciation and selective determination of Cr(III) in natural water samples using flow injection with chemiluminescence detection
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Abstract<p>A simple, rapid, sensitive and inexpensive approach is described in this work based on a combination of solid‐phase extraction of 8‐hydroxyquinoline (8HQ), for speciation and preconcentration of Cr(III) and Cr(VI) in river water, and the direct determination of these species using a flow injection system with chemiluminescence detection (FI–CL) and a 4‐diethylamino phenyl hydrazine (DEAPH)–hydrogen peroxide system. At different pH, the two forms of chromium [Cr(III) and Cr(VI)] have different exchange capacities for 8HQ, therefore two columns were constructed; the pH of column 1 was adjusted to pH 3 for retaining Cr(III) and column 2 was adjusted to pH 1 for retaining of Cr(VI). The sorbe</p> ... Show More
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Publication Date
Wed Feb 01 2023
Journal Name
Petroleum Science And Technology
Lithofacies and electrofacies models for Mishrif Formation in West Qurna oilfield, Southern Iraq by deterministic and stochastic methods (comparison and analyzing)
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Publication Date
Tue Mar 28 2017
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
Synthesis of new Conjugates of some NSAIDs with Sulfonamide as Possible Mutual Prodrugs using Tyrosine Spacer for Colon Targeted Drug Delivery
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The purpose of this research work is to synthesize conjugates of some NSAIDs with sulfamethoxazole as possible mutual prodrugs to overcome the local gastric irritation of NSAID with free carboxyl group by formation of ester linkage that supposed to remain intact in stomach and may hydrolyze in intestine chemically or enzymatically; in addition to that attempting to target the synthesized derivative to the colon by formation of azo group that undergo reduction only by colonic bacterial azo reductaze enzyme to liberate the parent compound to act locally (treatment of  inflammation and infections in colon).

Key words: Mutual prodrug, Ester linkage, Azo bond, Colon targeting

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Publication Date
Fri Feb 02 2024
Journal Name
Kurdish Studies
The Impact of the Brain Consensus Model on the Acquisition of Arabic Grammar Concepts for Female Students in the Fourth Grade
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Objectives: To identify the impact of the brain consensus model on the acquisition of Arabic grammar concepts among students in the fourth grade, methodology: The pilot curriculum was used, and a partial control pilot design was adopted. There were 30 female students in the pilot group, 30 female students in the control group, and the two researchers were statistically rewarded among the two groups' students in some variables and used appropriate statistical means to analyse the results, including the test for two independent samples, the square (c2) and the Alpha Kronbach equation.Results: The pilot group outperformed the control group. The results showed that there is a significant statistical difference at the indicative level (0.05) for

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Publication Date
Tue Aug 15 2023
Journal Name
Journal Of Economics And Administrative Sciences
The Impact of Gross Domestic Product Response to the Money Supply Shock in the Iraqi Economy for the Period (2004-2021)
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The research aims to clarify the response of the GDP to the M1 shock. It includes access to the results using standard methods, where the standard model was built according to quarterly data using the program STATA 17. According to the joint integration model ARDL, the research found a long-term equilibrium positive for the relationship between GDP and the money supply in Iraq, as the change in the money supply by a certain percentage will lead to a change in GDP by about 71% of that percentage. In the event of a shock in the Iraqi economy, the impact of the M1 will differ from what it was before the shock, as the shock will increase its effectiveness towards GDP by about 10% more than before the shock. At the same time, the relationship

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Publication Date
Sat Apr 01 2023
Journal Name
Heliyon
Role of immobilised Chlorophyta algae in form of calcium alginate beads for the removal of phenol: isotherm, kinetic and thermodynamic study
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Publication Date
Mon Apr 04 2011
Journal Name
Ibn Al-haitham J.for Pure &appl.sci
Anew Spectrophotometric Method For The Determination of La (III) With 3-Hydroxy -4-(2-hydroxy –Phenyl azo)Naphthalene -1-Sulfonic Acid
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A simple, rapid and sensitive spectrophotometric method has been proposed for the determination of La (III) using 3-hydroxy -4-(2-hydroxy-phenyl azo) naphthalene -1- sulfonic acid as a chromogenic reagent. This method is based on the formation of a red-pink colored complex, upon the reaction of La(III) with the reagent in an alkaline medium (pH= 9.50), having a maximum absorbance at 459 nm. Beer's law is valid in the concentration range 0.512 µg.ml-1 with a Sandell's sensitivity value of 0.0188 µg.cm-2 and molar absorptivity of 7376.12 L.mol-1.cm-1. The stoichiometric composition of the chelate is 1:3. The effect of the presence of different cations as interferants in the determination of La(III) under the given optimum conditions wer

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Publication Date
Thu Dec 31 2020
Journal Name
Iraqi Journal Of Market Research And Consumer Protection
SYNTHESISAND STUDY OF THE COMPLEXES OF: N-(3,4,5-TRIMETHOXY PHENYL)-N- BENZOYL THIOUREA (TMPBT) WITH A NUMBER OF TRANSITION METALS AND THEIR INDUSTRIAL AND MEDICAL IMPORTANCE: SYNTHESISAND STUDY OF THE COMPLEXES OF: N-(3,4,5-TRIMETHOXY PHENYL)-N- BENZOYL THIOUREA (TMPBT) WITH A NUMBER OF TRANSITION METALS AND THEIR INDUSTRIAL AND MEDICAL IMPORTANCE
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This paper performance for preparation and identification of six new complexes of a number of transition metals Cr (lII), Mn (I1), Fe (l), Co (II), Ni (I1), Cu (Il) with: N - (3,4,5-Trimethoxy phenyl-N - benzoyl Thiourea (TMPBT) as a bidentet ligand. The prepared complexes have been characterized, identified on the basis of elemental analysis (C.H.N), atomic absorption, molar conductivity, molar-ratio ,pH effect study, I. Rand UV spectra studies. The complexes have the structural formula ML2X3 for Cr (III), Fe (III), and ML2X2 for Mn (II), Ni (II), and MLX2 for Co (Il) , Cu (Il).

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