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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
Sun Feb 10 2019
Journal Name
Journal Of The College Of Education For Women
The Influence of Teacher and Students Errors Correction Techniques on Students’ Achievement in English at College of Physical Education for Women
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The research is an attempt to investigate experimentally the influence of teacher’s errors correction and students’ errors correction on teaching English at the College of Physical Education for Women. Errors are seen as a natural way for developing any language but teachers are puzzled the way they can correct these errors. So, this research gives some idea of using two types of errors correction. The sample of the research is female students of the first year stage at the College of Physical Education for Women of the academic year 2009-2010. The whole population of the research is (94) students while the sample is (64). Thus, the sample represents 68% from the population of the research. The sample represents It is hypothesized th

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Publication Date
Fri Feb 01 2019
Journal Name
Journal Of Economics And Administrative Sciences
Impact of quantitative (indirect) instruments of monetary policy on some indicators of financial stability in Iraq for the period (2003-2016)
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The indirect monetary policy tools led to financial stability for the period being studied through the use of indicators of financial stability (aggregate) to show the effect of the foreign reserves of the Central Bank of Iraq and its indirect instruments in achieving financial and economic stability, especially after the significant decline in oil prices and dependence of the Iraqi economy on Oil (rent) and lower reserves of the Central Bank of Iraq after 2014 and now compared to previous years, the goal of this research is to achieve financial stability according to selected indicators and achieve an optimal monetary policy to achieve the development goals of The economic policy in the country. Standard models were used to test

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Publication Date
Fri Jun 30 2023
Journal Name
Iraqi Geological Journal
Integrated Core and Log Data to Determine the Reservoir Flow Unit and Rock Facies for Mishrif Formation in South Eastern Iraq
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This work represents study the rock facies and flow unit classification for the Mishrif carbonate reservoir in Buzurgan oil Field, which located n the south eastern Iraq, using wire line logs, core samples and petrophysical data (log porosity and core permeability). Hydraulic flow units were identified using flow zone indicator approach and assessed within each rock type to reach better understanding of the controlling role of pore types and geometry in reservoir quality variations. Additionally, distribution of sedimentary facies and Rock Fabric Number along with porosity and permeability was analyzed in three wells (BU-1, BU-2, and BU-3). The interactive Petrophysics - IP software is used to assess the rock fabric number, flow zon

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Publication Date
Thu Jun 30 2022
Journal Name
Iraqi Journal Of Science
Novel Tamoxifen Citrate-Loaded Polymeric Nanoformulations for Improving Treatment and uses in medical applications: An In Vitro and In Vivo Study
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Tamoxifen citrate (TAM) is one of the most regularly used therapy in hormone receptor-positive breast cancer. Although it is a successful treatment, there is a problem with its bioavailability, accordingly this study was designed to improve TAM solubility and reduce its associated toxicity. TAM-Loaded poly (D, L-lactide –co- glycolide) nanostructure (TAM-loaded PLGA) has been synthesized and employed both in vitro and in vivo experiments. The blood hemolysis induced by TAM- loaded PLGA was 4.6 % at 200 µg mL-1, indicating that this nano-construct led to increased red blood cell protection. DNA molecule integrity was assessed and results indicated that DNA strands were protected from destruction at 200 µg mL-1. T

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Publication Date
Mon Oct 10 2022
Journal Name
Research Journal Of Chemistry And Environment
Synthesis, Antioxidant ability and Docking study for new 4,4'-((2-(Aryl)-1H-benzo[d]imidazole-1,3(2H)- diyl)bis(methylene))diphenol)
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New series of 4,4'-((2-(Aryl)-1H-benzo[d]imidazole1,3(2H)-diyl)bis(methylene))Diphenol(3a-g) was successfully synthesized from cyclization of the reduction product of bis Schiff bases (2) with aryl aldehydes bearing phenolic hydroxyl in the presence of acetic acid. The structure of these compounds was identified from FT-IR, 1H NMR, 13C NMR and EIMs. The Antioxidant capability was screened by DPPH and FRAP assays. Both assays showed antioxidant capability more than BHT as well. Compounds 3b and 3c showed antioxidant capacity slightly less than ascorbic acid. The docking study for theses compound was carried out as III DNA polymerase inhibitor. The results of docking demonstrated that the increase in hinderances around phenolic hydroxyl for t

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Publication Date
Sun Sep 25 2022
Journal Name
Research Journal Of Chemistry And Environment
Synthesis, Antioxidant ability and Docking study for new 4,4'-((2-(Aryl)-1H-benzo[d]imidazole-1,3(2H)-diyl)bis(methylene))diphenol)
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New series of 4,4'-((2-(Aryl)-1H-benzo[d]imidazole-1,3(2H)-diyl)bis(methylene))Diphenol(3a-g) was successfully synthesized from cyclization of the reduction product of bis Schiff bases (2) with aryl aldehydes bearing phenolic hydroxyl in the presence of acetic acid. The structure of these compounds was identified from FT-IR, 1H NMR, 13C NMR and EIMs. The Antioxidant capability was screened by DPPH and FRAP assays. Both assays showed antioxidant capability more than BHT as well. Compounds 3b and 3c showed antioxidant capacity slightly less than ascorbic acid. The docking study for theses compound was carried out as III DNA polymerase inhibitor. The results of docking demonstrated that the increase in hinderances around phenolic hydr

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Publication Date
Sat Jun 01 2013
Journal Name
Journal Of Economics And Administrative Sciences
"Using Markov Switching Model to Investigate the Link between the Inflation and Uncertain Inflation in Iraq for the periods 1980-2010"
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In this paper we use the Markov Switching model to investigate the link between the level of Iraqi inflation and its uncertainty; forth period 1980-2010 we measure inflation uncertainty as the variance of unanticipated  inflation. The results ensure there are a negative effect of inflation level on inflation uncertainty and  all so there are a positive effect of inflation uncertainty on inflation level.                                                   &nbsp

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Publication Date
Sun Sep 01 2013
Journal Name
Journal Of Economics And Administrative Sciences
The Role Of The economic And External Factors In Selecting Aggregate Planning Alternatives For Workforce Case Study In Yarmouk Teaching Hospital
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The research aimed to achieve many objectives represented in two variables, which are the impacted factors and the aggregate planning alternatives of workforce in Educational Al- yarmouk Hospital , This research started from a problem focused on finding solutions to the demand’s  fluctuation  or the energy limitation while the study importance is emerged from diagnosis the suitable strategy and adopt the suitable alternatives due to their importance in meeting the demand for the health service submitted by the hospital .This study  based on choosing assumptions of connection relationship and the impact among the mentioned variables in the(surgery and internal diseases) departments. The research is dependent on ch

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Publication Date
Sun Dec 02 2012
Journal Name
Baghdad Science Journal
Study of Spectroscopy and Thermodynamic Properties for Phoshours dioxide PO2 Molecular and Influence Study of Bond ( P-O ) on Spectroscopy Properties
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In This research a Spectroscopic complement and Thermodynamic properties for molecule PO2 were studied . That included a calculation of potential energy . From the curve of total energy for molecule at equilibrium distance , for bond (P-O), the degenerated of bond energy was (4.332eV) instate of the vibration modes of ( PO2 ) molecule and frequency that was found active in IR spectra because variable inpolarization and dipole moment for molecule. Also we calculate some thermodynamic parameters of ( PO2 ) such as heat of formation , enthalpy , heat Of capacity , entropy and gibb's free energy Were ( -54.16 kcal/mol , 2366.45 kcal/mol , 10.06 kcal /k/mol , 59.52 k

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Publication Date
Fri Jun 24 2022
Journal Name
Iraqi Journal Of Science
Influence of Cutting Position with IBA Hormone for Different Dipping Times on Rooting of Cassia tree Cassia surattensis Burm. Stem Cuttings
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The present study was carried out in the experimental in the nursery at Al – Dorah (Baghdad). During spring 2015 under natural environmental conditions in plastic house to evaluated the effect of different concentrations of IBA (100, 300, 500, 700 and 1000( mg/1 on different cutting position (basal, sub terminal and terminal) for different dipping times (24, 48) hours, on Cassia surattensis Burm. stem cuttings rooting. After 2 months of planting the results demonstrated that the basal cutting treated with 1000 mg/l IBA in 48 hours dipping time showed the earlier rooted period (4) weeks compared with control treatment 8 weeks. The same treatment also gave the highest mean rooting numbers 1.56per cutting and the highest mean rooting leng

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