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An in vitro evaluation of fit of the crowns fabricated by zirconium oxide-based ceramic CAD/CAM systems, before and after porcelain firing cycles and after glaze cycles
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Background: The objective of this in vitro study was to evaluate the vertical marginal fit of crowns fabricated with ZrO2 CAD/CAM, before and after porcelain firing cycles and after glaze cycles. Materials and Methods: An acrylic resin model of a left maxillary first molar was prepared and duplicated to have Nickel-Chromium master die. Ten die stone dies were sent to the CAD/CAM (Amann Girrbach) for crowns fabrication. Marginal gaps along vertical planes were measured at four indentations at the (mid mesial, mid distal, mid buccal, mid palatal) before (Time 0) and after porcelain firing cycles (Time 1) and after glaze cycles (Time 2) using a light microscope at a magnification of ×100. One way ANOVA LSD tests were performed to determine whether the mean and standard deviation of sub group Time 2. Results: The mean values of the ZrO2 CAD/CAM Time 0 were (6.77?m), Time 1(8.75?m) and Time 2(10.62 ?m). One way ANOVA test revealed highly statistical significance(P<0.01). LSD test results showed that there is highly significant difference between time (0) and time (2), while there is no any significant difference between time (0) and time (1), and between time (1) and time (2). Conclusions: Within the limitations of this study, it was concluded that the ZrO2 CAD/CAM demonstrated acceptable marginal fit; The porcelain firing and the glaze firing cycles affected the marginal gap

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Publication Date
Wed Oct 30 2024
Journal Name
Iraqi Journal Of Science
Evaluation of the Activity of Olibanum Oil as an Immune Booster in Rats
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The applications of herbal medicine have recently acquired growing interest in range of the prophylaxis and treatment of diseases. Olibanum has been used since ancient eras and several reports studied the pharmacological characteristics of boswellic acid, particularly their effect on the inflammatory response, analgesic properties, and anti-arthritic activity mostly in cell lines, but new approaches include animal models to assess these natural derivatives effects taking into consideration of being safer than synthetic preparations.  The impact of olibanum oil on several parameters was studied in rats during this study. These included white blood cell (WBC) count, lactate dehydrogenase (LDH), and C reactive protein (CRP), as well a

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Publication Date
Tue Feb 14 2023
Journal Name
Journal Of Educational And Psychological Researches
Administrative Applications of Expert Systems in Educational Leadership Departments in the Light of the Systems Approach
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Abstract

The aim of the current research is to identify the level of administrative applications of expert systems in educational leadership departments in light of the systems approach. To achieve the objectives of the research, the descriptive-analytical and survey method was adopted. The results showed that the level of availability of the knowledge base for expert systems in educational leadership departments (as inputs) was low. The level of availability of resources and software for expert systems in educational leadership departments (as transformational processes) came to be low, as well as the level of availability of the user interface for expert systems in educational leadership departments (as outputs

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Publication Date
Sun Jul 09 2023
Journal Name
Journal Of Engineering
The Effect of Ceramic Coating on Performance and Emission of Diesel Engine Operated on Diesel Fuel and Biodiesel Blends
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In this work, the effect of ceramic coating on performance, exhaust gas temperature and gases emissions of diesel engine operated on diesel fuel and biodiesel blends was investigated. A conventional four stroke, direct injected, single cylinder, diesel engine was tested at constant speed and at different load conditions using diesel fuel and biodiesel blends. The inlet and exhaust valves, the head of piston and cylinder head of the engine were coated by ceramic materials. Ceramic layers were made of (210-240) μm of Al2O3 and (30-60) μm of 4NiCr5Al as a bond coat for inlet and exhaust valves and (350-400) μm of YSZ and (50-100) μm of 4NiCr5Al as a bond coat for head of piston and (280-320) μm of Sic and (40-80) μm of 4NiCr5Al as a b

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Publication Date
Fri Feb 28 2020
Journal Name
Neuroquantology
Using X-Ray Films for Evaluation efficiency of Unsaturated Polyester Reinforced by Lead Oxide as Shielding for Medical X-ray Devices
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The largest use of x-ray in medical by dentists, employers or persons that needed by patients with specific conditions, lead to higher exposure of x-ray that may cause many diseases. In the present work radiography films have been used in evaluating the efficiency of using unsaturated polyester polymer reinforced with lead oxide (PbO) as shield material for medical x-ray devices, many parameters studied like concentration and thickness that they are increasing the attenuation of x-ray in them. The results show that the attenuation of X-ray increasing with concentration of reinforced material and with thickness, and the optical density decreases with increasing concentration from 0% to 50%, we chose 30% as suitable concentration to increase

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Publication Date
Thu Nov 27 2025
Journal Name
Bulletin Of The Chemical Society Of Ethiopia
Impact of defect-containing graphene oxide nanosheets on the structural, electrical, and dielectric characteristics of graphene oxide
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In this work, two graphene oxide (GO) samples were prepared using the Hummers method with graphite (g) and KMnO4 (g) ratios of 1:3 (GO3) and 1:6 (GO6). The effect of oxidation degree on the structural, electrical, and dielectric properties of the GO samples was investigated. The structures of the GO samples were studied using various techniques, including X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDXS). XRD analysis revealed an increase in the interlayer spacing and a decrease in the number of layers of the samples with increasing oxidant content. The two GO samples have giant permittivity values of ~105 in the low-frequency

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Publication Date
Mon Jun 04 2018
Journal Name
Baghdad Science Journal
Fabricated of Cu Doped ZnO Nanoparticles for Solar Cell Application
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Copper with different concentrations doped with zinc oxide nanoparticles were prepared from a mixture of zinc acetate and copper acetate with sodium hydroxide in aqueous solution. The structure of the prepared samples was done by X-ray diffraction, atomic force microscopy (AFM) and UV-VIS absorption spectrophotometer. Debye-Scherer formula was used to calculate the size of the prepared samples. The band gap of the nanoparticle ZnO was determined by using UV-VIS optical spectroscopy.

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Publication Date
Wed Feb 20 2019
Journal Name
Iraqi Journal Of Physics
Synthesis, characterization, and optical properties of copper oxide thin films obtained by spray pyrolysis deposition
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     Copper oxide thin films were synthesized by using spray pyrolysis deposition technique, in the temperature around 400°C in atmosphere from alcoholic solutions. Copper (II) chloride as precursor and glass as a substrate. The textural and structural properties of the films were characterized by atomic force microscopy (AFM), X-ray diffraction (XRD). The average particle size determined from the AFM images ranged from 30 to 90 nm and the roughness average was equal to 9.3 nm. The XRD patterns revealed the formation of a polycrystalline hexagonal CuO. The absorption and transmission spectrum, band gap, film thickness was investigated. The films were tested as an

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Publication Date
Mon Oct 01 2018
Journal Name
Journal Of Engineering
Synthesis and Characterization of Magnetic Iron Oxide Nanoparticles by Co-Precipitation Method at Different Conditions
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Magnetic nanoparticles (MNPs) of iron oxide (Fe3O4) represent the most promising materials in many applications. MNPs have been synthesized by co-precipitation of ferric and ferrous ions in alkaline solution. Two methods of synthesis were conducted with different parameters, such as temperature (25 and 80 ̊C), adding a base to the reactants and the opposite process, and using nitrogen as an inert gas. The product of the first method (MNPs-1) and the second method (MNPs-2) were characterized by x-ray diffractometer (XRD), Zeta Potential, atomic force microscope (AFM) and scanning electron microscope (SEM). AFM results showed convergent particle size of (MNPs-1) and (MNPs-2) with (86.01) and (74.14)

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Publication Date
Sun Feb 24 2019
Journal Name
Iraqi Journal Of Physics
Study the effect of gamma radiation on the some properties of glass and glass-ceramic immobilize nuclear waste
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Vitrifications process one of the important methods to immobilize nuclear waste.  In this research nuclear waste (Strontium Oxides) with molecular weight (5%) was immobilized by vitrification methods in two types of borosilicate glass (c-type) which are glass and glass-ceramics. To investigate the physical, chemical and mechanical properties of glass and glass-ceramic after immobilize nuclear waste these samples irradiated by gamma ray radiation. Co-60 was used as gamma a irradiation with dose rate 0.38 kGy/hr for different period of time. It’s found that gamma radiation affected the glass and glass-ceramic properties. From phase analysis by the x-ray diffraction for glass-ceramic samples proved that at doses 343kGy change the cry

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Publication Date
Sat Dec 01 2018
Journal Name
Baghdad Science Journal
Seasonal variation and modeling of disinfection by-products (DBPs) in drinking water distribution systems of Wassit Province Southeast Iraq
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