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Optimization of sintering temperature for the enhancement of pyroelectric properties of lead-free 0.88(Na0.5Bi0.5)TiO3–0.084(K0.5Bi0.5)TiO3–0.036BaTiO3 piezoelectric ceramics
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Lead-free 0.88(Na0.5Bi0.5)TiO3–0.084(K0.5Bi0.5)TiO3–0.036BaTiO3 (BNT–BKT–BT) piezoelectric ceramics were prepared using the conventional mixed-oxide method with a sintering temperature range of 1120–1200 °C. The effect of the sintering temperature on the crystal structure, microstructure, and densification, as well as the dielectrics, piezoelectrics, and the pyroelectric properties of BNT–BKT–BT ceramics were investigated. Scanning electron microscopy and X-ray diffraction were used to study the microstructures of the sintered samples. The results showed that the increase in sintering temperature was very effective in improving both the density and electrical properties. However, the samples deteriorated when the sintering temperature was above the optimum. The BNT–BKT–BT ceramics exhibited an excellent structure and electrical properties at a 1180 °C sintering temperature. The density of the ceramics reached a maximum value of 5880 kg/cm3, which is about 98% of the theoretical density. The ceramic exhibited a pyroelectric coefficient of (p) 366 μC/m2 K, a piezoelectric coefficient of d33 = 183 pC/N, a remanent polarisation of Pr = 38.43 μC/cm2, a dielectric constant of ε′ = 933, a loss tangent (tan δ) of 0.0235, and the figure-of-merit for detection was (FD) of 15.408 μPa1/2. Improvement in the pyroelectric properties is crucial for the development of infrared detectors and sensors.

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Publication Date
Sun Jun 01 2014
Journal Name
Baghdad Science Journal
Effect of sintering time on Bi1.6Pb0.4Sr1.8Ba0.2Ca2Cu3O10+? compound quenched in air and liquid nitrogen
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High temperature superconductor with nominal composition Bi1.6Pb0.4Sr1.8Ba0.2Ca2 Cu3O10+? was prepared by solid state reaction method. Two sets of samples have been prepared .The first one was quenched in air; the second set was quenched in liquid nitrogen. X-ray diffraction analyses showed an orthorhombic structure with two phases, high –Tc phase (2223) and low-Tc phase (2212) in addition to that impure phase was found. It has been observed that quenched in air samples display a sharp superconducting transition and a higher-Tc phase than that of the quenched in liquid nitrogen samples.

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Publication Date
Sat Jan 05 2019
Journal Name
Iraqi Journal Of Physics
The Influence of RF power, pressure and substrate temperature on optical properties of RF Sputtered vanadium pentoxide thin films
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The V2O5 films were deposited on glass substrates which produce using "radio frequency (RF)"power supply and Argon gas technique. The optical properties were investigated by, UV spectroscopy at "radio frequency" (RF) power ranging from 75 - 150 Watt and gas pressure, (0.03, 0.05 and 0.007 Torr), and substrate temperature (359, 373,473 and 573) K. The UV-Visible analysis shows that the average transmittance of all films in the range 40-65 %. When the thickness has been increased the transhumance was decreased from (65-40) %. The values of energy band gap were lowered from (3.02-2.9 eV) with the increase of thickness the films in relation to an increase in power, The energy gap decreased (2.8 - 2.7) eV with an increase in the pressure and

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Publication Date
Wed Jul 05 2023
Journal Name
Chalcogenide Letters
Optimization physical properties of CdTe /Si solar cell devices fabricated by vacuum evaporation
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We investigated at the optical properties, structural makeup, and morphology of thin films of cadmium telluride (CdTe) with a thickness of 150 nm produced by thermal evaporation over glass. The X-ray diffraction study showed that the films had a crystalline composition, a cubic structure, and a preference for grain formation along the (111) crystallographic direction. The outcomes of the inquiry were used to determine these traits. With the use of thin films of CdTe that were doped with Ag at a concentration of 0.5%, the crystallization orientations of pure CdTe (23.58, 39.02, and 46.22) and CdTe:Ag were both determined by X-ray diffraction. orientations (23.72, 39.21, 46.40) For samples that were pure and those that were doped with

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Publication Date
Wed Sep 01 2010
Journal Name
Al-khwarizmi Engineering Journal
Free Convection in an Inclined Concentric Annular Square Cavities Filled With Porous Medium and Heated By Non-Uniform Temperature
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A numerical study of the two-dimensional steady free convection flow in an inclined annulus between two concentric square cavities filled with a porous medium is presented in this paper for the case when the side outer walls are kept with differentially heated temperature while the horizontal outer walls and the inner walls are insulated. The heated wall is assumed to have spatial sinusoidal temperature variation about a constant mean value. The Darcy model is used and the fluid is assumed to be a standard Boussinesq fluid. For the Cartesian coordinate system, the governing equations which were used in stream function form are discretized by using the finite difference method with successive under – relaxation method (SUR) and are solv

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Publication Date
Wed Dec 27 2023
Journal Name
Journal Of Planner And Development
Contemporary formation indicators of free zones cities -Public Free zones models-
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The free zone or the free economy cities are cities with classification and functional specificity, although the history of  the concept of these areas has been It dates back to distant eras, but the intellectual and philosophical construction with the support of intellectual approaches, the most important of which is globalization contributed to its rapid spread globally and taking a variety of forms and models. With the diversity of its formulas and objectives countries have competed in adopting the establishment of these areas, meanwhile The influence of related trends affected the contemporary formation of these sites. Therefore ,the research was directed focus on the importance of adopting a set of common indicators (collection

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Publication Date
Tue Mar 01 2016
Journal Name
Al-academy
The aesthetic features of using Raku in ceramics Uta Grossmann Objects: غيد صادق عبد الغني
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The Ceramic was a part from the humanitarian production that masseure the development and promotion of the Nations through decades. The Ceramic development involve wide and more techniques. One of these techniques that appear through the developmental centuries, the ( Alkaro Ceramic )technique, this technique depended the simplicity that comitted on religions thoughts through their development and its origin, so it had connected with these religions thoughts and had transmitted to the differnt Nations and they development in it to stay as a connection to the original key although its a way to keep them from adoption a new path. The tracker of the Ceramic fine art through its modernal level could knew and touched the Enormons transformati

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Publication Date
Sat Dec 11 2021
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
The Formulation and Characterization of Nimodipine Nanoparticles for the Enhancement of solubility and dissolution rate
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Nimodipine (NMD) is a dihydropyridine calcium channel blocker useful for the prevention and treatment of delayed ischemic effects. It belongs to class ? drugs, which is characterized by low solubility and high permeability. This research aimed to prepare Nimodipine nanoparticles (NMD NPs) for the enhancement of solubility and dissolution rate. The formulation of nanoparticles was done by the solvent anti-solvent technique using either magnetic stirrer or bath sonicator for maintaining the motion of the antisolvent phase. Five different stabilizers were used to prepare NMD NPs( TPGS, Soluplus®, HPMC E5, PVP K90, and poloxamer 407). The selected formula F2, in which  Soluplus 

has been utilized as a stabilizer, has a par

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Publication Date
Tue Oct 01 2024
Journal Name
Journal Of Physics: Conference Series
An investigation into the implications of partial substitution of selenium with lead on the thermal properties for S<sub>60</sub>Se<sub>40-X</sub>Pb<sub>X</sub> Chalcogenide Compound
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Abstract<p>This study includes the manufacture of four ternary alloys represented S<sub>60</sub>Se<sub>40-X</sub>Pb<sub>X</sub> with weight ratios x = 0, 10, 20, and 30 by the melting point method. The components of each alloy were mixed separately, then placed in quartz ampoules and vacuumed out with a vacuum of roger that 10<sup>−4</sup> Torr. The ampule was heated in two stages to avoid sudden dissipation and precipitation of selenium on the inner mass of the quartz tube. The ampoule was gradually heated and kept at 450°C for approximately 4 hours followed by 950°C for 10 hours.at a rate of 10 degrees Celsius, the temperature of the electric furnace</p> ... Show More
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Publication Date
Fri Dec 01 2017
Journal Name
2017 11th Asian Control Conference (ascc)
ESO-based repetitive control for rejecting periodic and aperiodic disturbances in piezoelectric actuators
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This paper presents the Extended State Observer (ESO) based repetitive control (RC) for piezoelectric actuator (PEA) based nano-positioning systems. The system stability is proved using Linear Matrix Inequalities (LMIs), which guarantees the asymptotic stability of the system. The ESObased RC used in this paper has the ability to eliminate periodic disturbances, aperiodic disturbances and model uncertainties. Moreover, ESO can be tuned using only two parameters and the model free approach of ESO-based RC, makes it an ideal solution to overcome the challenges of nano-positioning system control. Different types of periodic and aperiodic disturbances are used in simulation to demonstrate the effectiveness of the algorithm. The comparison studi

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Publication Date
Thu Jun 30 2022
Journal Name
Iraqi Geological Journal
Assessment of the Contamination of Baghdad Soils with Lead Element
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The present study aims to study the content and spatial distribution of lead (Pb) contamination in the soils of some Baghdad cities (Middle of Iraq). Twenty soil samples were randomly collected from different land-use in the studied area at a depth between 5 to 30 cm. Ten samples are collected from Al-Rissafa side areas (Adhamiya, Al-Wazeeria (Battery Manufacturer), Shikh Omer, Ziyouna, Karada, Shaab, Sadr city, Al-Za’franiya, Al-Dora expressway, and Alselikh ) and other ten samples are collected from Al-Krakh side areas Al-Dora, Al-Masafi junction, Al-Dora, Sayidia, Al-Salam university college, Al-Bayaa (Industrial District), Jehad, Amirya, Abu Ghraib, Al-hurriya, and Kadhimiya. The soil samples have been analyzed for the lead (P

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