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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
Tue Mar 01 2016
Journal Name
Applied Research Journal
Response of R.C. Barriers Subjected to TNT Explosion Blast Loading
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Reinforced concrete barriers have been commonly used in protecting the important building because the response of R.C. barriers subjected to blast loading is practically more acceptable than other materials used to build the barriers. In this study, the response of R.C. barriers was detected due to the blast effects caused by two charge weights (50 kg and 400 kg); ANSYS 14 was used to simulate the problem. A horizontal distance of 2 m between the explosive TNT charge and the front face of wall was taken. The pressure on the front face of the concrete barriers was measured at three levels. The R.C. barrier was entirely damaged when subjected to the blast effects caused by 400 kg TNT explosion bomb. However, the 50 kg TNT charge had

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Publication Date
Sun Aug 18 2019
Journal Name
Proceedings Of Mechanical Engineering Research Day 2019,
Study of sound absorption of micro perforated panel with visco-thermal effects
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Publication Date
Mon Jan 01 2018
Journal Name
Fme Transaction
The influence of frictional facing thickness on the contact pressure distribution of multi-disc dry clutches
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Frictional heat is generated when the clutch starts to engag. As a result of this operation the surface temperature is increased rapidly due to the difference in speed between the driving and driven parts. The influence of the thickness of frictional facing on the distribution of the contact pressure of the multi-disc clutches has been investigated using a numerical approach (the finite element method). The analysis of contact problem has been carried out for a multiple disc dry clutch (piston, clutch discs, separators and pressure plate). The results present the distribution of the contact pressure on all tShe surfaces of friction discs that existed in the friction clutch system. Axisymmetric finite element models have been developed to ac

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Publication Date
Sun Nov 01 2020
Journal Name
Journal Of Engineering
Nonlinear Finite Element Analysis of RCMD Beams with Large Circular Opening Strengthened with CFRP Material
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This paper presents the non-linear finite element method to study the behavior of four reinforced rectangular concrete MD beams with web circular openings tested under two-point load. The numerical finite elements methods have been used in a much more practical way to achieve approximate solutions for more complex problems.  The ABAQUS /CAE is chosen to explore the behavior of MD beams. This paper also studies, the effect of both size and shape of the circular apertures of MD beams. The strengthening technique that used in this paper is externally strengthening using CFRP around the opening in the MD beams. The numerical results were compared to the experimental results in terms of ultimate load failure and displace

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Publication Date
Sat Jan 11 2025
Journal Name
Al-fatih Journal
Some cognitive sense of kinesthetic and spatial relationship to the level of learning some skills in the ground dictated by hardwareResearch and descriptiveStudents on the third phase of the Faculty of Physical Education for Girls - University of Baghdad
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إن النجاح في أداء المتطلبات الفنية والخططية في أي من الألعاب ألرياضيه يستوجب امتلاك العناصر الاساسيه المتعلقة بطبيعة الاداء ونوع الفعالية الرياضية الممارسة , لذا فان اغلب الألعاب الرياضية تعتمد على مكونات ألقدره التوافقيه والادراكيه الحسيه بوصفها احد العناصر الاساسيه في المستويات العليا لما توفره من قاعدة اقتران للصفات البدنيه والحر كيه وقدرات أجهزة الجسم الوظيفية , وفقا للأسس المعتمدة في بناء مهاراته, وع

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Publication Date
Mon Jun 01 2015
Journal Name
Journal Of Economics And Administrative Sciences
The phenomenon of negative behavior has studied as a social and psychological phenomenon that effect on the performance and life of workers inside and outside the organization. The adoption of this phenomenon is studied in terms of the role of the interna
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The phenomenon of negative behavior has studied as a social and psychological phenomenon that effect on the performance and life of workers inside and outside the organization. The adoption of this phenomenon is studied in terms of the role of the internal environment of the organization in addressing this behavior, being the variables belong to the field of organizational behavior to see the results of those variables on the Iraqi organizations, since the specificities of it differ from the rest of the Arab and foreign environments. Therefore, this study focused on testing the relationship of the internal environment of the organization and its role in addressing the negative behavior of the workers.

thi

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Publication Date
Sat Dec 17 2022
Journal Name
Journal Of The College Of Languages (jcl)
The Use of the Definite article in the Ottoman Turkish Language in the Fourteenth and Seventeenth Centuries: Qaboos Namah and Mazaki Collection as a Model: '' Kabusnâme ve Mezâkî Divanı Örneğinde ''14. ve 17. Yüzyılarda Osmanlı Türkçesinde Harf-i Ta'rifin Kullanması Üzerine Bir İnceleme
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The Turks used the Ottoman Turkish language from the thirteenth century to the twentieth century.  During this period and under the influence of Islamic civilization, a large number of words and structures were used from the Arabic and Persian languages, Therefore, many Arabic grammatical structures were used in the Ottoman Turkish language, such as the definite article simply because it was widely used.

The paper is concerned with the use of the Arabic definite article in the Ottoman Turkish language, and the aim of this contrastive study is to find out the similarities and differences between the two languages ​​in terms of meaning and structure. Since linguistic studies depend on the practical side or applied approach, two

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Publication Date
Sun Jun 02 2019
Journal Name
Journal Of The College Of Languages (jcl)
The Exploitation of Carmen Valero Garces' Theory in the Criticism of Literary Texts: Saleh al-Jafari's Arabic Translation of "Rubbayat al-Khayyam" as a: کاربست نظریه¬ی کارمن والرو گارسس در نقد ترجمه¬ی ادبی (مورد مطالعه: تعریب صالح الجعفری از رباعیات خیام)
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There is a mutual relationship between the form of a text and its meaning so as separating these two or devaluating the role of one of them leads to the absence of the value therein. Thus, a translation is important as to how it relates the details of a text. That is, the text has special features which go beyond form, and these set out its distinctiveness. Here, we tackle Saleh al-Jafari's Arabic translation of  "Rubbayat al-Khayyam" of Naysapour descriptively and analytically by depending on extracts from the original text. This translation is evaluated on the basis of Spanish critic Maria Carmen Valero Garces. Herein, we discuss the effectiveness of this theory in the criticism of literary texts. It has been concluded that al-Jaf

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Publication Date
Sat Dec 30 2023
Journal Name
Iraqi Journal Of Science
Evaluation of Isolated Compounds Activity from Convolvulus Arvensis Against Algae
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This study includes isolation, purification, and identification of algae from different aquatic environments in Baghdad city. Nine unialgal cultures were obtained. These algal cultures included 6 species of blue-green algae (Microcystis aeruginosa, Microcystis flos-aquae, Oscillatoria limnetica, Nostoc carneum, Westillopesis prolifica, Mastigocluds lamiosus), and 3 species of green algae (Mougeotia sclaris, Scenedesmus dimorphus and Chlorella vulgaris). In addition that aerial parts from Convolvulus arvensis were collected. Terpens, alkaloids and phenols were extracted of mentioned plant, and the antialgal activity of extracts types were evaluated in 3 concentrations (5, 10, and 20 mg/ml) by wells and diffused in the agar media. Results

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Publication Date
Wed Jun 30 2010
Journal Name
Al-kindy College Medical Journal
Evaluation the Effectiveness of Impregnated Net in Reducing Leishmaniasis Incidence: Diala-Iraq
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Background: Leishmaniasis is important public
health problem owing to its impact on morbidity
and mortality and difficulties in application of
effective control measures.
Objective: The aim of the study is to evaluate the
using of impregnate bed nets in the control of
leishmaniasis.
Methods: The study was conducted throughout
the years 2004 and 2005, in Diala Governorate
(about 60km north-east Baghdad). This is the first
study in Iraq for evaluation of the impregnated bed
net in control of leishmaniasis. Two villages were
selected to achieve this aim. The nets were
distributed for the first village to be used by their
population. The second village was served as
control.

Results: The

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