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Evaluation of shear bond strength of zirconia to tooth structure after different zirconia surface treatment techniques
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Background: This study aimed to evaluate the effect of zirconia different surface treatments (primer, sandblast with 50μmAl2O3, Er,Cr:YSGG laser) on shear bond strength between zirconia surface and resin cement. Material and methods: Sixty presintered Y-TZP zirconia cylinder specimens (IPS e.max ZirCAD, Ivoclar vivadent) will be fabricated and sintered in high temperature furnace of (1500 C for 8 hours) according to manufacturer’s instructions to the selected size and shape of (5mm. in diameter and 6mm in height). All specimens were ground flat using 600.800.1000.1200, aluminum oxide abrasive paper to obtain a standardized surface roughness. Surface roughness values were then recorded in µm using surface roughness tester (profilometer) to obtain a standardized data base line for all samples. The specimens were then randomly divided into three main groups (n=20); group A: no surface treatment (control group), group B: specimens in this group treated with 50μm Al2O3 and group C: specimens in this group treated with Er,Cr:YSGG laser. Sixty sound human premolars were used in this study, after construction of acrylic blocks, the occlusal surface of the teeth were ground flat, with diamond cutting disk to obtain a flat dentine surface . Prior to cementation of zirconia cylinders to tooth specimens subgroups (A1,B1,C1) will receive a coat of metal/zirconia primer and left to react for three minutes, while the subgroups (A2,B2,C2) were left undisturbed. Bonding surface of zirconia cylinder was then luted with SpeedCEM self adhesive resin cement under a static load of 2Kg. placed on the vertical arm of the surveyor and allowed to auto cure for 4minutes.The final cemented specimens were then stored in distilled water at room temperature for 24hours. All specimens were subjected to shear loading force in a universal testing machine at crosshead speed of 1mm/min. The shear bond strength values were analyzed statistically with one-way ANOVA; the fractured surfaces of zirconia cylinders were examined with a stereo-microscope to observe the failure mode. Results: The air borne-particle of 50μm followed by primer application showed significantly the higher bond strength than other groups. Conclusion : Within the limitation of this study, the results showed that sandblasting the bonding surface of zirconium cylinders with 50μmAl2O3 produced the highest values of shear bond strength , also the use of primer enhanced shear bond strength as well. Keyword: zirconia surface treatments, shear bond strength.

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Publication Date
Sat Oct 01 2022
Journal Name
Journal Of Applied Geophysics
Predicting dynamic shear wave slowness from well logs using machine learning methods in the Mishrif Reservoir, Iraq
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Publication Date
Sun Mar 12 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
The Study of Chromosomal Structure in Mystus pelusius (Solander in Russell,1794) Fish
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  The present study was done to identify the karyotype of Mystus pelusius fish , which is the only representative of the family Bagridae in Iraq, they have been caught from Tigris river in AL-Kraat area of Baghdad city, the results show that the diploid chromosome number was 2n=32 and the males chromosomal types included 2n=(6m+13sm+7st+6t)and fundamental number FN=51, in females chromosomal types included 2n=(6m+12sm+8st+6t)with FN=50,also it observed that the first submetacentric pair was the largest within the biarmed chromosomes .The results revealed that the male heterogamety and the female homogamety , accordingly it follows the sex determination system (XX / XY) , as the (X) chromosome represented by medium sized submetacentr

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Publication Date
Mon Apr 10 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Morphological Description and Histological Structure of Olfactory Organ in Barn Owl (Tyto alba)
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   The Morphological description and histological structure of olfactory organ in barn owl have been studied. The results of morphological description showed that the olfactory organ in the animal under study have pair of external nares ovale shape which lead to pair of nasal chambers which are located at the dorsal surface of head under eyes level. The chambers are conical in their shape the anterior end is narrow while the posterior end is enlarger the nasal chambers open to the oral cavity through the internal nares.      The results also showed that the nasal cavity contains three chonchae which represented by rosteral chonchae, elongated middle chonchae and the posterior nasal chonchae called olfac

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Publication Date
Wed Jun 01 2011
Journal Name
Journal Of Madenat Alelem College
Morphological description and Histological structure of the liver in Passer domesticus (House sparrow)
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This study showed that liver of Passer domesticus bilobed the right lobe is cardiac shape while the left is elliptical and the liver colour is brown. It is occupying most of anterior and middle parts of abdominal cavity. The liver is surrounded by Glison capsule which is represented by a thin layer of connective tissue with septum extend peripherally in liver tissue. The liver tissue is formed from polyhedral hepatocyte arrange as irregular hepatic cord surrounded the central vein. Each cell contains one or two nucleus with one or more nucleolus. The blood sinusoid appeared between the liver cells .The hepatic cord arranged radially around the central vein. The portal area is clear and surrounded by connective tissue. Gallbladder is almost

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Publication Date
Sat May 01 2021
Journal Name
Journal Of Physics: Conference Series
Anatomical histological structure of the cerebellum in the Iraqi frog Rana ridibunda ridibunda
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Abstract<p>The current study was designed to investigate the histological structure of the cerebellum in the Iraqi frog <italic>Rana ridibunda ridibunda</italic>. The cerebellum was removed surgically from 20 Iraqi frogs, <italic>Rana ridibunda ridibunda</italic>, and preserved in fixative of 10% formalin solution for a period of 72 hr, then the histological sections were prepared by the method of paraffin. The results of the study showed that the cerebellum of the adult Iraqi frog is one of the rhombencephalon regions, and consists of three layers, molecular layer, purkinje cells layer, and granular layer. The present histological findings suggest that the cerebellum of the </p> ... Show More
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Publication Date
Thu Oct 31 2013
Journal Name
Al-khwarizmi Engineering Journal
Aeroelastic Behavior of a Wind Turbine Blade by a Fluid -Structure Interaction Analysis
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In this paper, a numerical model for fluid-structure interaction (FSI) analysis is developed for investigating the aeroelastic response of a single wind turbine blade. The Blade Element Momentum (BEM) theory was adopted to calculate the aerodynamic forces considering the effects of wind shear and tower shadow. The wind turbine blade was modeled as a rotating cantilever beam discretized using Finite Element Method (FEM) to analyze the deformation and vibration of the blade. The aeroelastic response of the blade was obtained by coupling these aerodynamic and structural models using a coupled BEM-FEM program written in MATLAB. The governing FSI equations of motion are iteratively calculated at each time step, through exchanging data between

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Publication Date
Tue Apr 05 2022
Journal Name
International Journal Of Criminology And Sociology
The Arabic Root and the Peculiarities of Its Language Categorization (Structure and Inflection)
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This article discusses the peculiarities of the Arabic root, its phonemic structure, and morphological categorization. The pure appearance of the Arabic root in language categorization allows you to separate the onomatopoeic feature of inflectional structure and phonetic rules of the Arabic language by which the root is categorized. This phenomenon of meaningful consonant phonemes in the Arabic roots makes the theory of onomatopoeia practicable not just only in Arabic but also in other Semitic languages. Moreover, the first consonant of an Arabic root usually contains the word's primary, essential meaning, and the second and third lookup. Also, in this work, it is noted that the grammar of the Arabic language has many features aimed

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Publication Date
Mon Apr 01 2019
Journal Name
2019 International Conference On Automation, Computational And Technology Management (icactm)
Multi-Resolution Hierarchical Structure for Efficient Data Aggregation and Mining of Big Data
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Big data analysis is essential for modern applications in areas such as healthcare, assistive technology, intelligent transportation, environment and climate monitoring. Traditional algorithms in data mining and machine learning do not scale well with data size. Mining and learning from big data need time and memory efficient techniques, albeit the cost of possible loss in accuracy. We have developed a data aggregation structure to summarize data with large number of instances and data generated from multiple data sources. Data are aggregated at multiple resolutions and resolution provides a trade-off between efficiency and accuracy. The structure is built once, updated incrementally, and serves as a common data input for multiple mining an

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Publication Date
Tue Jan 01 2013
Journal Name
The Education Faculty Journal Of Baghdad University
Analyzing the Rhetorical Structure of Linguistics Dissertation Abstracts Written by Iraqi EFL Graduates
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Publication Date
Wed Oct 31 2018
Journal Name
Iraqi Journal Of Science
Structure and Morphological Properties of In2O3 Nanostructure Prepared by Pulse Laser Ablation Method
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     A colloidal indium oxide (In2O3) nanoparticles (NPs) were synthesized pulsed laser ablation (PLA) of  indium  plate placed on the bottom of the quartz vessel containing (3ml) of pure ethanol. The influence laser energy on the properties of the formed nano-particles  were characterized by using atomic force microscopy (AFM), X-ray diffraction (XRD), Ultraviolet Visible (UV-Vis) technique, and electrical properties measurements. The XRD revealed the crystallization  structure of  In2O3  nanoparticles and all the films having preferential orientation along (222) plane and intensity increases with increasing laser energy, The UV–Visible spect

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