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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
Sat Nov 05 2022
Journal Name
Resmilitaris
Job Burnout Among Social Workers in Iraqi society: A Social Study
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There are a number of obstacles in the field of work of social workers that prevent them from performing their full role. Their tasks may sometimes be easy and manageable and at other times they may be difficult and complex, however professional roles are mostly the latter, contribute to the feeling of the inability to provide the work required at the level expected by others. In such cases, the relationship binding specialists to their work is affected negatively and this has devastating effects on the professional process as a whole, including their professional practice. This feeling of helplessness and depletion of energy and effort leads to a state of fatigue and emotional exhaustion that can be defined as job burnout, our study aims t

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Publication Date
Sat Jun 01 2013
Journal Name
Int. J. Nanoelectronics And Materials
The response of a window glass to the frequencies of sound
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Publication Date
Tue Jan 01 2019
Journal Name
Indian Journal Of Public Health Research & Development
Serum Vitamin D Levels in a Sample of Iraqi Female Patients
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Background: Recurrent aphthous stomatitis (RAS) is one of the most common oral mucosa diseases characterized by recurrent, shallow, round or oval painful oral ulcers surrounded by inflammatory erythematous halos, the condition is chronic and self-limiting in immunocompetent patients. Aim of the study: to investigate the serum vitamin D levels in Iraqi female patients with RAS and the relationship between vitamin D levels and the severity of RAS. In this cross sectional study 30 female patients with idiopathic RAS, and 30 age and sex matched healthy controls were included, the severity of RAS is assessed by the number of oral aphthous ulcers in each attack and the frequency of attacks. Serum 25(OH) D levels were determined by the Enzy

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Publication Date
Fri May 01 2020
Journal Name
Journal Of Physics: Conference Series
A CERTAIN SUBCLASS OF MULTIVALENT HARMONIC FUNCTIONS DEFINED BY RUSCHEWEYH DERIVATIVES
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Abstract<p>We introduce a new class of harmonici multivalent functions define by generalized Rucheweyh derivative operator. We also obtain several interesting propertiesi such as sharp coefficienit estimates, distortioni bound, extreme points, Hadamardi product and other several results. Derivative; extreme points.</p>
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Publication Date
Sun Dec 31 2023
Journal Name
International Journal For Humanities &amp; Social Sciences (ijhs)
‘Ambivalence’ as a Concept in John Clare's Middle and Late Poetry
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        This paper signifies the contradictory point of view in John Clare’s poetry. Clare (1794-1864) is an English romantic poetry in the nineteenth century, who writes more than ten volumes about nature. So, this study highlights the concept of Psychoanalytic theory which is ‘ambivalence’ and how through this theory can interpret any literary text on the basis of utilizing psychoanalytic methods to literary texts in order to reveal the author's inner emotions such as motives, dreams, as well as wishes. Consequently, the concept of  ‘ambivalence’ has a lot in common with the human psyche and its struggles. Sometimes the reader finds the author/poet talking about something real or a notion with pleasant sentiments

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Publication Date
Mon Jan 18 2016
Journal Name
Publications Of The Astronomical Society Of The Pacific
Extreme Contrast Ratio Imaging of Sirius with a Charge Injection Device
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Publication Date
Sun Jan 01 2023
Journal Name
Medical Journal Of Babylon
Platelet-rich Fibrin Potential Role in Periodontal Regeneration: A Review Study
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Periodontitis is a persistent bacterial-causing disease which damages the supporting periodontium of the teeth. The complexity of supporting tissue structure makes the regeneration a challenge for periodontists. Early investigations were focused on discovering therapeutic substitutes that are biocompatible, simple to prepare and economic. This might cause a local release of growth factors that accelerate the healing process of the soft and hard tissue. Recently, platelet-rich fibrin (PRF) has received a wide attention as a biocompatible regenerative material in both dental and medical fields. PRF is a natural fibrin-derived biomaterial, and it is easy to obtain. It can be gotten from individual blood without the use of any external anticoag

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Publication Date
Mon Jul 25 2022
Journal Name
International Journal Of Health Sciences
Ca242 as a potential prognostic marker in colorectal cancer Iraqi patients
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Background: Colorectal cancer is the third most common cancer-related mortality worldwide, and its prevalence is increasing among many nations.  Aim of the study: Investigate the predictive value of carbohydrate antigen 242 (CA242) in comparison to the CEA biomarker and to estimate the significance of CA242 as prognosis maker in colorectal cancer patients. Methods: a case-control study with a total of 150 individuals, 100 patients (59 males, 41 females) and 50 healthy controls (26 males, 24 females). using an enzyme-linked immunosorbent (ELISA) to determine the serum levels of CA242 and CEA. The study was carried out at the gastroenterology consultation clinic of the oncology teaching hospital between November 2020 and February

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Publication Date
Sun Sep 07 2008
Journal Name
Baghdad Science Journal
A Study of some biochemical parameters in patients with &#61538;- thalassemia
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Serum levels of iron,copper,ceruloplasmin and transferrine were estimated in three groups of patients with ?- thalassemia: 24 patients have splenectomy thalassemia major, 29 patients have non splenectomy thalassemia major and 19 patients have thalassemia intermedia , data were compared to normal and pathological controls (anemia and minor). There were significant increase in trace element levels in all studied groups of pateints as compared to normal and pathological controls. Also there were a significant increase in ceruloplasmin levels,While the result revealed that there were a significant decrease in transferrine levels in all groups of patients studied as compared to normal and pathological controls. The result also indicate that the

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Publication Date
Sat Jul 01 2023
Journal Name
Analytical Science & Technology
A Review: Synthesis and characterization of metals complexes with paracetamol drug
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In this review, previous studies on the synthesis and characterization of the metal Complexes with paracetamol by elemental analysis, thermal analysis, (IR, NMR and UV-Vis (spectroscopy and conductivity. In reviewing these studies, the authors found that paracetamol can be coordinated through the pair of electrons on the hydroxyl O-atom, carbonyl O-atom, and N-atom of the amide group. If the paracetamol was a monodentate ligand, it will be coordinated by one of the following atoms O-hydroxyl, O-carbonyl or N-amide. But if the paracetamol was bidentate, it is coordinated by atoms (O-carbonyl and N-amide), (O-hydroxyl and N-amide) or (O-carbonyl and O-hydroxyl). The authors also found that free paracetamol and its complexes have antimicrobial

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