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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
Thu Aug 01 2024
Journal Name
Materials Science In Semiconductor Processing
Enhancing charge transfer in 0D/2D cobalt sulfide/boron-doped graphitic carbon nitride heterojunction photocatalyst for degradation of organic pollutants under LED illumination
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Semiconductor-based photocatalytic processes are widely applied as ecofriendly technology for degrading organic pollutants. Establishing photocatalytic heterojunctions with Z-type photocarriers transfer pathways is projected to be a superb strategy to enhance photocatalytic behavior. In this paper, novel and stable (0D/2D) heterojunctions of CoS-embedded boron-doped g-C3N4 (CoS/BCN) with a high rate of charges transfer/separation were assembled for degradation of malachite green dye (MG). The CoS/BCN photocatalyst achieves a photodegradation efficiency of 96.9 % within 1 h of LED illumination, which is 2.5 and 1.4-fold enhancement compared with bare g-C3N4 and BCN, respectively. Besides, the results of species-trapping trials exhibited that

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Publication Date
Mon Jun 21 2021
Journal Name
Journal Of Mechanics Of Continua And Mathematical Sciences
OPTIMIZATION OF FUZZY DIFFERENTIAL EQUATION-BASED FARDL MODELS FOR ENGINEERING APPLICATIONS: COMPARATIVE ANALYSIS OF LINEAR AND QUADRATIC ESTIMATORS VIA PARALLEL MONTE CARLO SIMULATIONS
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Today's smart engineering systems are often faced with situations that are structurally uncertain, informationally incomplete, and non-probabilistically ambiguous, especially for electrical systems. ARDL models are limited in applications in complex computational environments where the uncertainty is due to vagueness, not randomness, and assume the exact parametric representation of the models and the structure of the stochastic uncertainty. This study proposes a new soft-computing paradigm using Fuzzy Autoregressive Distributed Lag (FARDL) models and compares the performance of the Linear Programming (LP) and Quadratic Programming (QP) estimation algorithms using large-scale parallel Monte Carlo simulations to overcome these drawba

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Publication Date
Sun Jan 17 2021
Journal Name
Academic Journal Of Interdisciplinary Studies
Employees Retention Strategy and its Impact on Organizational Memory: An Exploratory Research for the opinion of Faculty Members at Private Colleges on Baghdad
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The research aims to determine the impact of employees’ retention strategy on organizational memory. This research is historical, descriptive, and analytical. The sample consists of 158 faculty members in five private colleges in Baghdad. The technique used to analyze the data is SEM (Structural Equation Modeling), and SPSS (Statistical Package for the Social Sciences). The research concludes that the employees retaining strategy plays a vital role in retaining employees and hence maintains organizational memory. The findings and recommendations of this research assure the administrations of private colleges that employees retention strategy play a vital role in retaining its employee and hence maintains organizational memory. T

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Publication Date
Sun Apr 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
Effect of Development International Financial Reporting Standards (IFRS) in Quality of Accounting Information for sample of banks listed on the Iraq Stock Exchange
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The bodies responsible for the organization of accounting in the world seek to keep abreast of repaid development, by provide the information required by users, which they need to make efficient decision that return them to the desired benefits, and avoid the risks they could face if they made their decision based on misleading information, or insufficient, or not accurate, Hence, the IASB has undertaken to review the standards, and make the necessary adjustment and clarifications to remove the ambiguities that some of the paragraphs may have in IFRS issued.

And the Iraqi Central Bank obliges banks to convert from local accounting standards to apply IFRS only a step towards keeping pace with developments

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Publication Date
Fri Jun 30 2023
Journal Name
The International Tinnitus Journal
Adenoidectomy and Endoscopic Myringotomy with and without ventilation tube insertion for Treatment of Otitis Media with Effusion in 6-12 years old Children
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Publication Date
Sun Apr 15 2001
Journal Name
University Of Baghdad, College Of Veterinary Medicine
A Study of Antimicrobial Effect of Oil Extracts of Black Seed (Nigella sativa L.) on some Pathogenic Microorganism that is isolated from Clinical Pathogenic Cases.
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Publication Date
Wed Aug 05 2026
Journal Name
Journal Of Economics And Administrative Sciences
The Impact of Management by Walking Around on the Strategic Renewal of Business Organizations (Field Research in a Sample of Excellent grade hotels - in Baghdad)
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يهدف هذا العمل الى بيان طبيعة العلاقة بين الادارة بالتجوال والتجديد الاستراتيجي ، ومدى تأثير المتغير المستقل في المتغير التابع. تضمنت فقرات الاستبانة بوصفه الأداة الرئيسة لجمع البيانات ثلاث جوانب اساسية، تضمن الاول البيانات الشخصية للمستجيبين، فيما تضمن الجانب الثاني الفقرات الخاصة بمتغير الادارة بالتجوال من خلال خمسة ابعاد، فيما اشتمل الجانب الثالث على فقرات التجديد الاستراتيجي عبر تناول اربعة ابعاد. ي

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Publication Date
Mon Oct 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
A comparative study of the role of monetary policies in achieving economic growth in some oil and non-oil countries during the period 1990-2017
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The research problem was to identify the impact of monetary policies on economic growth in the oil and non-oil countries. The researcher chose the Republic of Iraq as an example for the oil countries and the Arab Republic of Egypt as an example for the non-oil countries to hold a comparison on the impact of monetary policies.

The research found that the monetary policies and their tools in the Iraqi economy affect the rate of GDP growth by 73%, which shows the strong impact of monetary policies on the economic growth in the Iraqi economy as an example of an oil state. GDP growth rate of 61%, indicating the impact of monetary policies on economic growth in the

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Publication Date
Thu Sep 01 2011
Journal Name
Journal Of Economics And Administrative Sciences
Leadership ethics and transformational leadership to develop perceptions of organizational work supportA survey of a sample of the staff of the Ministry of Water Resources
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The aim of organizational contemporary is development man power active, in spit-of there are littlie resources. But in the Iraqi environment there are too much resources with performance inhabiting. specially in the ministry of water resources (sample of this research), about dryness and lower levels of rivers. There for this study have some important variable, it is ethical leadership & transformational leadership as (independent variable), and Perceived organizational support(dependent variable). Over here to invest with authority on the problem of research, is weakness harmony between employed perception and the pattern of leadership. We find decline in of reaction of organ compound between the variable to weaken high perf

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Publication Date
Sun Mar 08 2020
Journal Name
Biochem. Cell. Arch
SYNTHESIS AND SPECTROSCOPIC CHARACTERIZATION OF NEW HETEROCYCLIC COMPOUNDS DERIVATIED FROM 1-(4-AMINOPHENYL) ETHAN-1-ONEOXIME AS A STARTING MATERIAL WITH EVALUATE THEIR BIOLOGICAL ACTIVITY
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ABSTRACT : This research involves the synthesis of five to seven heterocyclic compounds starting with Schiff’s bases which derived from oxime as a starting material. 1.3-oxazepine derivatives were prepared from adding different anhydrides to the Schiff bases, tetrazole and thiazolidinone derivatives synthesized from add sodium azide and thioglycolic acid to the same Schiff’s bases as a five members ring. Pyrimidine derivatives were prepared after the reaction of the azomethine group with acetyl chloride and then urea and thiourea to synthesis on derivatives contain the six members ring. Another step included identified and confirmed these compounds by FT- IR, 1HNMR, TLC and 13CNMR finally, step included the assay of biological activity

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