Preferred Language
Articles
/
jbcd-638
Evaluation of shear bond strength of zirconia to tooth structure after different zirconia surface treatment techniques
...Show More Authors

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.

View Publication Preview PDF
Quick Preview PDF
Publication Date
Mon Jan 28 2019
Journal Name
Iraqi Journal Of Science
Extraction and Delineation of Pera Magroon Alluvial Fans North East Iraq Using Remote Sensing Techniques and GIS application
...Show More Authors

Pera Magroon anticline is located within the northeastern of Iraq, covering area estimated by 958 Km2. The Landsat ETM+ false color composite imagery was produced by assigning [741] bands. It is used to distinguish alluvial fans in the southwestern limb of Pera Magroon anticline. Digital elevation models (DEM) were used for describing topographic features related to the alluvial fans, as well as, three dominations model (3D) was created from (DEM) and the Landsat ETM+ image.

 Arc GIS, hydro tool set was used to draw the drainage patterns, the area of study was covered by dendritic and parallel patterns. Contour lines across the fans form segments of ellipses reveal the pattern of tectonic act

... Show More
View Publication Preview PDF
Publication Date
Tue Nov 01 2022
Journal Name
Iraqi Journal Of Applied Physics
Highly-Pure Nanostructured Metal Oxide Multilayer Structure Prepared by DC Reactive Magnetron Sputtering Technique
...Show More Authors

In this work, metal oxides nanostructures, mainly, copper oxide (CuO), nickel oxide (NiO), titanium dioxide (TiO2), and multilayer structure were synthesized by dc reactive magnetron sputtering technique. The structural purity and nanoparticle size of the prepared nanostructures were determined. The individual metal oxide samples (CuO, NiO and TiO2) showed high structural purity and minimum particle sizes of 34, 44, 61 nm, respectively. As well, the multilayer structure showed high structural purity as no elements or compounds other than the three oxides were founds in the final sample while the minimum particle size was 18 nm. This reduction in nanoparticle size can be considered as an advantage for the dc reactive magnetron sputtering tec

... Show More
View Publication Preview PDF
Publication Date
Sat Oct 19 2019
Journal Name
Geotechnical And Geological Engineering
Local Scale Displacement Fields in Grains–Structure Interactions Under Cyclic Loading: Experiments and Simulations
...Show More Authors
Abstract<p>Soils encounter cyclic loading conditions in situ, for example during the earthquakes and in the construction sequences of pavements. Investigations on the local scale displacements of the soil grain and their failure patterns under the cyclic loading conditions are relatively scarce in the literature. In this study, the local displacement fields of a dense sand layer interacting with a rigid footing under the plane-strain condition are examined using both experiments and simulations. Three commonly used types of cyclic loading conditions were applied on the footing. Digital particle image velocimetry (DPIV) is used to measure the local scale displacement fields in the soil, and to understand the ev</p> ... Show More
View Publication
Scopus (10)
Crossref (10)
Scopus Clarivate Crossref
Publication Date
Wed Dec 27 2017
Journal Name
Al-khwarizmi Engineering Journal
A New Structure for Cascaded Single-Stage Distributed Amplifier Using Proposed Active Inductor Loads
...Show More Authors

A modification to cascaded single-stage distributed amplifier (CSSDA) design by using active inductor is proposed. This modification is shown to render the amplifier suitable for high gain operation in small on-chip area. Microwave office program simulation of the Novel design approach shows that it has performance compatible with the conventional distributed amplifiers but with smaller area. The CSSDA is suitable for optical and satellite communication systems.

View Publication Preview PDF
Publication Date
Wed Jun 01 2016
Journal Name
Journal Of The College Of Languages (jcl)
BARBARA : structure et signification Étude analytique du langage prévertien à travers son poème Barbara
...Show More Authors

Cette recherche étudie les structures composant Barbara, un poème de Jacques Prévert pour mettre en valeur la particularité de ce langage. Nous avons d'abord, dissocié ces structures, en : structure thématique, actancielle, syntaxico-énonciative, sémantique, formelle et finalement spacio-temporelle en vue de les analyser minutieusement. Le poète a adopté pour les thèmes : souvenir, nostalgie et guerre, un langage simple et une syntaxe incomplexe. L'usage du lexique et des figures de style célèbrent ces thèmes. La forme, la versification et la sonorité approfondissent ces images et renforcent ce langage. Ce poème dépend des phrases simples et variées : affirmative, interrogative, exclamative qui s'orientent vers des acte

... Show More
View Publication Preview PDF
Publication Date
Mon Jan 29 2018
Journal Name
Iraqi Journal Of Science
In2O3-ZnO pyramids like structure prepared by Spray-pyrolysis Technique for gas Sensing Applications
...Show More Authors

Polycrystalline Indium oxide (In2O3) and Indium oxide-zinc oxide (IZO) thin films mixed with 10% ZnO content were prepared by spray-pyrolysis technique at relatively low substrate temperature (150 ˚C).Field emission scanning electron microscope (FE-SEM) shows that the nanostructure at 10% ZnO content has pyramid like structure. The hall effect measurements show that the prepared samples have n-type charge carriers .The films were examined as gas sensor against H2S gas at different operating temperatures (200, 250 and 300) oC, and it was found that the IZO sample a good sensitivity to H2S gas ~ 572 % at operating temperature 200 oC, with relatively fast response time of 19 s and recovery time of 17

... Show More
View Publication Preview PDF
Publication Date
Tue Sep 15 2020
Journal Name
Al-academy
Visual Variables in Exterior Advertisements Design Structure: أكرم جرجيس نعمة -عبد الله جاسم غريب
...Show More Authors

  What makes the commercial advertisement distinct is the design structure which is built according to artistic and creative concepts and terms based on the visual and formal interdependence relationships to express the motives of the advertising idea, which is based in its action mechanism on the effective variables, some of which are related to the marketing aspect, and others related to the advertisement aspect. The major aspect is the functional and aesthetic variables, which are represented by the vocabulary of the advertisement area for the open spaces such as the street ads. Its promotional dimension is the active forces in the circulation of commodities and products. Therefore, there would be significant problems the designe

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Feb 20 2019
Journal Name
Political Sciences Journal
Article The problem of nuclear proliferation and its impact on the formula of strategic balance in the Middle East after the events of September 11, 2001
...Show More Authors

The issue of nuclear proliferation is one of the most vital issues as it reflects a form of dealing in the field of international relations. Therefore, the Middle East region has taken great interest in reducing the levels of nuclear armament and acquiring nuclear power within the strategic framework of the international and regional powers. The establishment of a nuclear-weapon-free zone in the Middle East region is currently one of the most important international and regional arrangements for controlling the levels of nuclear proliferation and attempting to build a state of stability and balance. In the Middle East and the world. The importance of the research comes from the fact that it deals with an important and vital issue

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Jul 01 2019
Journal Name
Journal Of Educational And Psychological Researches
The of Effect Instructional Design based on Kagan Structure In Generating Information Skills for First Intermediate Student’s In Mathematics
...Show More Authors

 

The aim of the research is to identify the effect of instructional design according to Kagan structure among the first intermediate school student’s, and how skills could help in generating information in mathematics. In accordance with the research objectives, the researcher has followed the experimental research method by adopting an experimental design with two equivalent groups of post-test to measure skills in generating information. Accordingly, the researcher raised two main null hypotheses: there were no statistically significant differences at the level of significance (0.05) between the average scores of the experimental group who studied the material according to Kagan structure and th

... Show More
View Publication Preview PDF
Publication Date
Mon Mar 25 2019
Journal Name
Al-academy
Direction Structure of the Imaginary and Interpretation Controversy in the Theatre Reception "Mukashafat" Play -A Model: ثابت رسول جواد
...Show More Authors

The current research deals with the argument of delusion and interpretation in the direction structure and its reflected impact in the reception activity and the amount of conceptual displacement it is subjected to in an aesthetic approach to abstract conceptual definitions of the reception activity , by the effect of this dialectic in the direction structure, which can be summed up by the following question: (What are the characteristics of the direction structure of the imaginary and what is the argument of interpretation in the theatre reception activity?) in order to stand on the aesthetic framework and conceptual definition of the direction structure in the controversy of interpretation and imagination, and its impact on the concept

... Show More
View Publication Preview PDF
Crossref