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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 Mar 15 2021
Journal Name
Al-academy
Visual illusion in Contemporary Theatre décor A Study in technical Variables: سامي علي حسين
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Our research deals with the role of theatrical decoration in creating visual thumbs and the effect achieved as a result in the theatrical presentation in terms of supporting the idea of centralization of the dramatic construction of the show, as the researcher emphasizes that this topic has begun with a new horizon removed many technical concepts and knowledge in the theater.
Horizon knowledge and discoveries based on the structures of light and sight to achieve an existing transformation from steel to ethereal. According to these new concepts, systems other than those based on old methods of presentation have been formed.
In light of this, the researcher divided his research into:
First: the problem of research and the need fo

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Publication Date
Sun Mar 20 2016
Journal Name
Al-academy
Modeling of violence in a speech creativity photogrammetry Iraqi contemporary: أريج سعد عدنان الهنداوي
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The latest events in Iraq and notably the fall of Mosul in the summer of 2014 have marked a turning point in The modern history of Iraq. Violent terrorist groups have overrun a vast area comprising of many towns in mid and northern Iraq causing many casualties and mass migration. Despite Iraq’s long history of pain and suffering the events of the second half of the year 2014 have been the most violent ever witnessed. From this point of view the researcher has tried to identify specifically in this time and place the effect these events have had on the Iraqi artist and to understand how the Iraqi artists depicted this violence in their works of art. The research comprises four parts; the first looked at the language used and the and pro

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Publication Date
Sun Jun 12 2011
Journal Name
Baghdad Science Journal
A Study of Wear Rate Epoxy Resin filled with SiO2 particle and Glass fibers
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This research is devoted to study the effect of different in weight percentage of Sio2 particles and glass fibers (5, 10, 15, 20) wt. % on the wear rate epoxy resin. The results show that the value of hardness increase with the increase for the weight percentage of reinforcing particles and fibers, while the wear rate decrease with the increase the load level of the reinforcing particles and fibers . The largest value of the hardness, and the lowest value of the wear rate for epoxy reinforced with 20% of SiO2, the wear rate increase in general with increasing the applied load.

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Publication Date
Fri Apr 01 2022
Journal Name
International Journal Of Pharmacy Practice
Exploring job satisfaction among pharmacy professionals in the Arab world: a multi-country study
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Abstract<sec> <title>Objectives

The study objectives were to (1) describe the characteristics of the pharmacy professionals and (2) explore the association between job satisfaction and factors, such as work control, work stress, workload and organization and professional commitments.

Methods

This study was a cross-sectional design. The survey items were mainly adapted from the US National Pharmacist Workforce Survey. An electronic (Qualtrics) questionnaire was posted on pharmacist social media in several A

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Publication Date
Tue Jun 01 2021
Journal Name
Iop Conference Series: Earth And Environmental Science
Variation of non-diatomic algae in a martyr monument lake under different climate factors
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Abstract<p>The current study was conducted in the environment of the Martyr Monument Lake in the city center of Baghdad during 2019 to monitor the impact of climatic conditions such as drought, water shortage, high temperatures in the environment of the city and the lack of water flow during the years 2015 to 2018 and their effects on some of the physical and chemical factors of water and the dynamics of the phytoplankton community in the lake environment. Heterogeneity of some studied environmental factors, including air and water temperature, permeability, water depth, pH, DO, BOD5, nutrients, nitrate, NO3, and phosphates were found. The results showed the effect of climate change and the pres</p> ... Show More
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Publication Date
Sun Jun 01 2014
Journal Name
Baghdad Science Journal
Efficacy of Saccharomyces cerevesiae on promoting growth in tomato: Nahida M.Saleh |Adnan A. Issa
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This study was conducted to evaluate the efficacy of Saccharomyces cerevesiae as a growth promoting agent in tomato. Soaking the seeds in yeast suspension at 5 g/L for 12h increased germination percentage, root length, root fresh and dry weight, plant height, foliage fresh and dry weight, attained 88.5% ; 8.1 cm ; 84.3 mg ; 7.03 mg ; 10.75 cm ; 839 mg and 37.75 mg compared with 80% ; 5.33 cm ; 39 mg ; 4.8 mg ; 7.35 cm ; 608 mg and 25.5 mg in seedlings grown from non treated seeds respectively. Similar results were obtained with seedling from seeds soaked in S. cerevesiae filtrate for 12 hrs. with values of 77.5% ; 6.875 cm ; 91.5 mg ; 7.5 mg ; 9.5 cm ; 777 mg and 40.35 mg compared to 66% ; 5.8 cm ; 57.7 mg ; 5.03 mg ; 5.9 cm ; 493 mg

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Publication Date
Wed May 01 2019
Journal Name
Heliyon
Toward liveable commercial streets: A case study of Al-Karada inner street in Baghdad
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Publication Date
Sat Dec 05 2020
Journal Name
International Journal Of Clinical Practice
Assessment of COVID‐19 Treatment containing both Hydroxychloroquine and Azithromycin: A natural clinical trial
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Publication Date
Wed Dec 27 2023
Journal Name
Biomed Research International
Efficacy of Autogenous Dentin Biomaterial on Alveolar Ridge Preservation: A Randomized Controlled Clinical Trial
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Background. After tooth extraction, alveolar bone resorption is inevitable. This clinical phenomenon challenges dental surgeons aiming to restore esthetic and function. Alveolar ridge preservation can be applied to minimize dimensional changes with a new socket grafting material, an autogenous dentin graft, produced by mechanically and chemically processing natural teeth. This study assessed the safety and efficacy of using autogenous dentin biomaterial in alveolar ridge preservation. Materials and Methods. Patients with nonrestorable maxillary anterior teeth bounded by natural sound teeth were included in this study. After a detailed clinical and tomographic examination, eligible participants were randomly allocated into two groups

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Publication Date
Wed Jan 18 2017
Journal Name
International Journal Of Pharmacy Practice
Antimicrobial utilization in an Iraqi province: a comprehensive evaluation of antibiotic source and cost
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