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Proportional-Derivative PD Vibration Control with Adaptive Approximation Compensator for a Nonlinear Smart Thin Beam Interacting with Fluid
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This work is concerned with the vibration attenuation of a smart beam interacting with fluid using proportional-derivative PD control and adaptive approximation compensator AAC. The role of the AAC is to improve the PD performance by compensating for unmodelled dynamics using the concept of function approximation technique FAT. The key idea is to represent the unknown parameters using the weighting coefficient and basis function matrices/vectors. The weighting coefficient vector is updated using Lyapunov theory. This controller is applied to a flexible beam provided with surface bonded piezo-patches while the vibrating beam system is submerged in a fluid. Two main effects are considered: 1) axial stretching of the vibrating beam that leads to the appearance of cubic stiffness term in beam modelling, and 2) fluid effect. Fluid forces are decomposed into two components: hydrodynamic forces due to the beam oscillations and external (disturbance) hydrodynamic loads independent of beam oscillations. Simulation experiments are implemented using MATLAB/SIMULINK to verify the correctness of the proposed controller. Two piezo-patches are bonded on the beam while an impulse force with multi-pulse is applied to excite the beam vibration. The results show the strength of the proposed control structure.

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Publication Date
Sat Oct 01 2016
Journal Name
Journal Of Engineering
The Application of Biomimicry in Kinetic Facades
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Biomimicry, as a way of thinking to go back to nature for inspiration, has its impact on many contemporary technological achievements. Some of them are used to design and construct kinetic facades in architecture, because of the importance role of facades in reducing sun radiation, that enter the building through using shading  systems and components. In light of this, research problem is determined: "Do technologies which are inspired by biomimicry effect shading in kinetic facades through its characteristics in materials and the mechanics. So the research identifies its goal as: "To identify the types of kinetic facades in buildings and their characteristics as materials and shading mechanism associated with the b

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Publication Date
Wed May 10 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Gross and Histological Structure of the Caudal Fin of Adult Mosquitofish , Gambusia Affinis , (Baird & Girard)
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The  present  study  showed  that  the  caudal  fin  of  adult mosquitofish  (Gambusia  affinis)  is  homocercal  and  rounded . It  consists  of  22-24 fin rays (Lepidotrichia) . Each fin ray  consists  of  many  segments . Some of these rays are short and  unbranched  whereas  others long and branched dichotomously. Pigment cells are shown to be dispersed on the fin and they are condensened at the edges of the fin rays and at the regions of their dichotomy .        Histologically the transverse section of the fin is surrounded by a fin membrane (composed of epidermis and dermis)

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Publication Date
Tue Sep 11 2018
Journal Name
Iraqi Journal Of Physics
The effects of silica addition on the structural, electrical and mechanical characteristics of MgAl2O4 spinel ceramic phase
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The ceramic compound Mg1-xSixAl2O4 (x= 0, 0.1, 0.2, 0.3, 0.4) was prepared from nano powder of Al2O3 and MgO doped with Nano powder of SiO2 at different molar ratios. The specimens were prepared by standard chemical solid reaction technique and sintered at 1450 oC. Structure of the specimens was analyzed by using X-ray diffraction (XRD). The X-ray patterns of the specimens showed the formation of pure simple cubic spinel structure MgAl2O4 phase with space group of ̅ . The average grain size and surface topology were studied by atomic force microscopy. The results showed that the average grain size was about 73-90 nm. The DC electrical properties of the specimen were measured. The apparent density was found to increase and the porosity a

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Publication Date
Sat Oct 01 2011
Journal Name
Journal Of Engineering
POLLUTION OF MINING INDUSTRY SULFUR PURIFICATION PLANT AT AL MISHRAQ
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The Al Mishraq site has been the subject of many scientific studies for the period before and
after the fire in 2003. Five visits to the site were conducted twice in 2003 for general fact-finding, twice
in 2004, and once in 2005 for detailed sampling and monitoring. Desk-based research and laboratory analysis of soil and water samples results indicate that surface water and groundwater pollution from Al Mishraq site was significant at the time of its operation. The primary pollution source was the superheated water injection process, while the principal receptor is the River Tigris. Now that the plant is idle, this source is absent. Following the June 2003 sulphur fire, initial investigations indicate that short damage to
vegeta

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Publication Date
Sun Jan 30 2022
Journal Name
Iraqi Journal Of Science
Enhancement of Digital Stereo Vision Images based on Histogram and Gamma Correction Strategy
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     Image contrast enhancement methods have been a topic of interest in digital image processing for various applications like satellite imaging, recognition, medical imaging, and stereo vision. This paper studies the technique for image enhancement utilizing Adaptive Histogram Equalization and Weighted Gamma Correction to cater radiometric condition and illumination variations of stereo image pairs. In the proposed method, the stereo pair images are segmented together with weighted distribution into sub-histograms supported with Histogram Equalization (HE) mapping or gamma correction and guided filtering.  The experimental result shows the experimented techniques outperform compare with the original image in ev

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Publication Date
Tue Dec 01 2009
Journal Name
Iraqi Journal Of Physics
Crystal Growth of High – Purity Bi2Se3 and Study of Crystal Structure
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The Bi2Se3 compound was synthesis by fusing initial compounds consisting of
extra pure elements in stoichiometric ratio from elements compound, charged inside
quartz ampoule. The crystal growth of Bi2Se3 carried out using Brighaman technique
process from melting f (Bi+Se ) at temperature of 810 ºC for about 48 hrs. Single crystal
of Bi2Se3 has been grown in direction (211) after slow cooling on account of heat
gradient to zone furnaces at cooling rate (1-3) C/hr. The structure study of the compound
was determined by x-ray diffraction technique, which it has bismuthinite structure and
orthorhombic unit cell with lattice parameters of a=10.2678 Å, b=11.2392 Å and
c=5.1737 Å

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Publication Date
Sun Nov 25 2018
Journal Name
Journal Of The Faculty Of Medicine Baghdad
Knowledge and Practice of Sectors of Health-Care Workers towards Universal Precautions in Baghdad Teaching Hospital
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Background: Universal precautions, as defined by centers for disease control (CDC), are a set of precautions designed to prevent transmission of human immunodeficiency virus , hepatitis B virus , and other blood borne pathogens when providing first aid or health care .
Objectives: To measure knowledge of and practice towards universal precautions among healthcare workers (apart from doctors) in Baghdad Teaching Hospital .
Material and methods: A cross-sectional study was conducted during the period of two months from 26th of February to the end of April 2007 in Baghdad Teaching Hospital / Medical City ,Baghdad to assess the knowledge and practice of 110 health care workers towards the use of universal preca

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Crossref
Publication Date
Thu May 18 2023
Journal Name
Journal Of Engineering
Thermo-hydrodynamic Analysis of Misaligned Journal Bearing Considering Surface Roughness and Non-Newtonian Effects
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This paper presents a numerical simulation for the combined effect of surface roughness and non-Newtonian behavior of the lubricant on the performance of misaligned journal bearing. The modified Reynolds equation to include the effect of non-Newtonian lubricant and bearing surface roughness has been formulated. The model accounts for the lubricant viscosity dependence on temperature and shear rate. In order to make a complete thermo-hydrodynamic analysis (THD) of rough surface misaligned journal bearing lubricated with non-Newtonian lubricant, the modified Reynolds equation coupled with the energy, heat conduction equations, the equation related the viscosity and temperature with appropriate boundary conditions have been solved simultane

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Publication Date
Sat Oct 01 2016
Journal Name
Journal Of Economics And Administrative Sciences
Throughput Accounting and its role in supporting and achieve competitive advantage
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Abstract\

Dealing economic units at the present time with an industrial environment characterized by competitiveness and the pace of change and its strength as a result of this changing environment shall be on those who made it to adopt strategies that allow them to confront these variables and work in order to meet the market requirements of quality and price appropriate products to suit and the demand for those products and conditions to maintain

its competitive position and its development.

As a result, it became the subject of competitiveness in recent years and enjoys widespread attention at the global level. And in order to keep up

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Crossref
Publication Date
Thu Sep 15 2022
Journal Name
Al-academy
Interaction and functional structural transformation of product design
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The research discussed the propositions of functional structures and the requirements for their transformation according to the variables of use and human interaction through the variables of functions with one form products، multifunctional variables، and transforming form in one product. The patterns of user’s interaction with products were discussed through the variables of functional type، starting from defining the types of functions in the industrial product structures to: practical functions، which were classified into: informational functions، ergonomic functions، use، handling، comfort، global، anthropometric adaptation and physical postures. While the interaction variables were discussed according to the meaning fun

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