Preferred Language
Articles
/
alkej-333
Active Vibration Suppression of Smart Cantilever Beam with Sliding Mode Observer Using Two Piezoelectric Patches
...Show More Authors

This paper presents a vibration suppression control design of cantilever beam using two piezoelectric ‎patches. One patch was used as ‎an actuator element, while the other was used as a sensor. The controller design was designed via the balance realization reduction method to elect the reduced order model that is most controllable and observable. ‎the sliding mode observer was designed to estimate six states from the reduced order model but three states are only used in the control law. Estimating a number of states larger than that used is in order to increase the estimation accuracy. Moreover, the state ‎estimation error is proved bounded. An ‎optimal LQR controller is designed then using the ‎estimated states with the sliding mode observer, to ‎suppress the vibration of a smart cantilever ‎beam via the piezoelectric elements. The control spillover problem was avoided, by deriving an avoidance ‎condition, to ensure the ‎asymptotic stability for the proposed vibration ‎control design. ‎The numerical simulations were achieved to ‎test the vibration attenuation ability of the ‎proposed optimal control. For 15 mm initial tip ‎displacement, the piezoelectric actuator found ‎able to reduce the tip displacement to about 0.1 ‎mm after 4s, while it was 1.5 mm in the ‎open loop case.  The current experimental results showed a good performance of the proposed LQR control law and the sliding mode observer, as well a good agreement with theoretical results.

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Fri Jan 01 2021
Journal Name
Aip Conference Proceedings
Study of rheological and mechanical properties of bitumen blended with two alpha phases of polyamide
...Show More Authors

The effect of D phase polyamide (PA6)on the rheological properties, Young Modulus and the thermal expansion coefficient of two blends groups (bitumen-polyamide) were tested. The first group was for bitumen-PA6 blends and the second group for bitumen blended with polymer resulted from the crystallization of PA6-formic acid solution in water(PAFW).The obtained results proved that adding both types of polyamide has led to a rise in toughness and softening point temperature while the penetration Index approached -3 after adding the polyamide. So, all these changes make bitumen-polyamide blends more suitable for use in hot climate regions. The blends properties were explained according to the reaction that takes place between the polyamide and

... Show More
Preview PDF
Scopus Crossref
Publication Date
Mon Apr 01 2013
Journal Name
Journal Of The Faculty Of Medicine Baghdad
Triplex ultrasound findings of chronic leg ischemia with clinical correlation
...Show More Authors

Background: Chronic leg ischemia commonly affects the arteries supplying the leg and mostly caused by atherosclerosis. Triplex ultrasound scanning is useful for delineating the anatomic site of disease in the lower limb in addition to the grading of the stenosis and evaluation of post-stenotic flow.

Objectives: To determine the extent of vasculopathy in patients with chronic leg ischemia by using triplex ultrasound scanning and match the sonographic findings with the clinical signs and symptoms.

Patients and methods: A cross sectional study from October 2009 to September 2010 was performed on 56 patients with clinical suspicion of chronic leg ischemia referring to ultraso

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Jan 02 2013
Journal Name
Journal Of The Faculty Of Medicine Baghdad
Determination of Parents' Resilience with Autistic child in Baghdad City
...Show More Authors

Background:Many parents of autistic child do well despite  their child’s disability, they have the ability to withstand hardship and rebound from adversity, and becoming more strengthened, parents have managed to overcome the constant challenge by using their resilience to adapt well in the face of adversity.

Patients and Methods: A Descriptive analytical study was carried out from May 25, 2009 to June 20, 2010 in order to determine parents' resilience in dealing with the impact of raising a child with autism.  A purposive (non-probability) sample of (100) parents raising a child with autism who was attending the out patient psychiatric clinic at Child's Central Teaching Hospital in B

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Dec 01 2014
Journal Name
Journal Of Economics And Administrative Sciences
Comparison between some of linear classification models with practical application
...Show More Authors

Linear discriminant analysis and logistic regression are the most widely used in multivariate statistical methods for analysis of data with categorical outcome variables .Both of them are appropriate for the development of linear  classification models .linear discriminant analysis has been that the data of explanatory variables must be distributed multivariate normal distribution. While logistic regression no assumptions on the distribution of the explanatory data. Hence ,It is assumed that logistic regression is the more flexible and more robust method in case of violations of these assumptions.

In this paper we have been focus for the comparison between three forms for classification data belongs

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Jan 01 2012
Journal Name
مجلة العلوم التربوية والنفسية
معوقات تدريس المواد التربوية والنفسية في كلية التربية – ابن الهيثم من وجهة نظر أعضاء هيئة التدريس فيها
...Show More Authors

Publication Date
Sun Nov 19 2017
Journal Name
Iraqi Journal Of Laser
Effects of Diode Laser 940 nm with and without 5 % Sodium Fluoride White Varnish with Tri-calcium Phosphate on Dentin Permeability (In vitro study)
...Show More Authors

It is found that hypersensitive teeth have a larger number and wider patent tubules than those of non-sensitive teeth. Objective: The aim of this study is to compare between the effects of diode laser at different power densities, with and without sodium fluoride on the sealing of exposed dentinal tubules and dentin permeability. Materials and methods: 118 teeth were used. Samples were divided into three major groups. The first consisted of 100 teeth used for permeability test. The second consisted of 16 teeth for measuring external surface temperature elevation while irradiation. The third, in turn, consisted of one pair of teeth observed under SEM for dentine surface morphology analysis. Results: For dentin permeability measurement, th

... Show More
View Publication Preview PDF
Publication Date
Fri Nov 24 2023
Journal Name
Iraqi Journal Of Science
Theoretical Study of Electronic Properties and Vibration Frequencies for Tri-Rings Layer (6, 0) Linear (Zigzag) SWCNT
...Show More Authors

DFT (3-21G, 6-31G and 6-311G/ B3LYP) and Semi-empirical PM3 methods were applied for calculating the vibration frequencies and absorption intensities for normal coordinates (3N-6) of the Tri-rings layer (6,0) Zigzag single wall carbon nanotube (SWCNT) at their equilibrium geometries which was found to have D6h symmetry point group with C-C bond alternation in all tube rings.as well as mono ring layer. Assignments of the modes of vibration were done depending on the pictures of their modes applying by Gaussian 03 program. The whole relations for the vibration modes were also done including (CH stretching, CC stretching, deformation in plane of the molecule (δCH, δring and δCCC), deformation out of plane of the molecule (CH and

... Show More
View Publication Preview PDF
Publication Date
Sat Jan 01 2022
Journal Name
Technologies And Materials For Renewable Energy, Environment And Sustainability: Tmrees21gr
Challenges facing the transition of traditional cities to smart: Studying the challenges faced by the transition of a traditional area such as Al-Kadhimiya city center to the smart style
...Show More Authors

Challenges facing the transition of traditional cities to smart: Studying the challenges faced by the transition of a traditional area such as Al-Kadhimiya city center to the smart style

View Publication
Scopus (1)
Scopus Crossref
Publication Date
Wed Feb 29 2012
Journal Name
Al-khwarizmi Engineering Journal
WLAN Integrated with GPRS Network Securely
...Show More Authors

In this paper a WLAN network that accesses the Internet through a GPRS network was implemented and tested. The proposed network is managed by the Linux based server. Because of the limited facilities of GPRS such as dynamic IP addressing besides to its limited bandwidth a number of techniques are implemented to overcome these limitations.

      Dynamic Host Configuration Protocol (DHCP) server was added to provide a single central control for all TCP/IP resources. Squid Proxy  was added to provide caching of the redundant accessed Web content to reduce the Internet bandwidth usage and speeding up the client’s download time. Network Address Translation (NAT) service was configured to share one IP ad

... Show More
View Publication Preview PDF
Publication Date
Sat Jan 11 2025
Journal Name
Journal Of Baghdad College Of Dentistry
Management of Independent Middle Mesial Canal in Mandibular First Molar Using Cone Beam Computed Tomography Imaging as an Adjunct – A Case Report
...Show More Authors

The primary objective of root canal therapy is adequate biomechanical preparation of root canal system followed by 3D obturation.in clinics we are encountered with several anatomical variations, which we need to manage efficiently. One of the major factors responsible for failure of root canal therapy is missed canals. Recent technological advances have given the clinician opportunity to identify anatomical variations and treat them to satisfaction.

View Publication Preview PDF
Crossref