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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 Sep 15 2018
Journal Name
Journal Of Baghdad College Of Dentistry
Evaluation of Hematocrit Level, Red Blood Cells and White Blood Cells Counts in Blood from Patients with Different Severities of Periodontal Diseases
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Background: Anemia of chronic disease (ACD) occurs in the presence of chronic infection, inflammatory conditions or neoplastic conditions despite of adequate iron and vitamins storage. Gingivitis is the inflammation of the gingiva, periodontitis is the inflammation in the periodontium that extend deeper with loss of connective tissue attachment and supporting bone. The main pathogenesis of periodontal diseases and ACD is immune activation. Aims of study: Determine and compare the clinical periodontal parameters (plaque index (PLI), gingival index (GI), bleeding on probing (BOP), probing pocket depth (PPD) and clinical attachment level (CAL)). Evaluate the hematocrit (Hct) level, red blood cells (RBCs) count and white blood cells (WBCs) c

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Publication Date
Sat Oct 01 2022
Journal Name
Baghdad Science Journal
Evaluation of atmospheric cold plasma technique activity on phenylpropanoids gene expression and essential oil contents and different traits of Ocimum basilicum L.
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The current study was conducted for studying the impact of cold plasma on the expression level of three genes that participate in the biosynthesis of the phenylpropanoid pathway in Ocimum basilicum. These studied genes were cinnamate 4-hydroxylase (c4h), 4-coumarate CoA ligase (4cl), and eugenol O-methyl transferase (eomt). Also, the cold plasma impact was studied on the essential oil components and their relation with the gene expression level. The results demonstrated that cold plasma seeds germination of the treated groups 2 (initially for 3 minutes and 3 minutes after 7 days) ,and group 3(initially for 5 minutes and 3 minutes after 7 days)  were faster than the control group. Also, the height average of the mature plants of

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Publication Date
Fri Jan 01 2016
Journal Name
Results In Physics
Optimization of dye extraction from Cordyline fruticosa via response surface methodology to produce a natural sensitizer for dye-sensitized solar cells
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Publication Date
Wed Feb 20 2019
Journal Name
Political Sciences Journal
China's Middle East policy after 2001
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The foreign policy of china is considered an important subject generally, in addition its very significant towards the Middle East specifically. It is the most valued topic, that needs deep academic investigations in order to identify the important factors causes and its consequences, this kind of research provides a proper understanding to the researchers and politicians, it will prove the reasons for China's with the impact to the region, the rivalry with the United States in the coming years

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Publication Date
Sun Feb 03 2019
Journal Name
Journal Of The College Of Education For Women
The Iraqi- Kuwaiti relations after 2003
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The Iraqi- Kuwaiti relations had witnessed a lot of problems which had its impact on them, at the fore front is the frontier issue, and the Iraqi invasion of Kuwait in 1990 which led to the severance of relations between them and had strengthened the disagreement and the dispute and raised the animosity and tension.
After 2003, Iraq has witnessed a lot of changes which affected Iraq and the region as a whole.
Under the new political developments in Iraq, a now phase has started in the relations between the two parts. which is based on the emphasis on building new relations based on the mutual respect and non intervention in the internal affairs of both countries, and in accordance with the principles of the international law, and w

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Publication Date
Sat Dec 01 2018
Journal Name
Political Sciences Journal
American - Irani Relations after Nuclear Agreement
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Summary

The fundamental turning point in American policy towards the Iran was the success of the Islamic revolution in Iran 1979 . Since than U S policy has been hostile to Iran . After the events 11 September 2001 , there was an American idea of dialogue with some countries opposed to US policy , including Iran . In 2004 the United States launched the Greater Middle East project , which contain a range of political , economic and cultural proposals for the region , all of which were in the interest of the United States and ( Israel ) , which Iran opposed . The failure of U S projects in region prompted the United States to agree with Iran on the nuclear file . On 8 May 2018 U S President Donald Trump of

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Publication Date
Mon Aug 01 2016
Journal Name
Journal Of Engineering
Non-Linear Behavior of Strengthened Steel-Concrete Composite Beams with Partial Interaction of Shear Connectors
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In this research a theoretical study has been carried out on the behavior and strength of simply supported composite beams strengthened by steel cover plate taking into consideration partial interaction of shear connectors and nonlinear behavior of the materials and shear connectors. Following the procedure that already has been adopted by Johnson (1975), the basic differential equations of equilibrium and compatibility were reduced to single differential equation in terms of interface slip between concrete slab and steel beam. Furthermore, in order to consider the nonlinear behavior of steel, concrete and shear connectors, the basic equation was rearranged so that all terms related to materials are isol

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Publication Date
Tue Dec 31 2013
Journal Name
Al-khwarizmi Engineering Journal
Thermo-Rheological Investigation and Modeling of the Shear Viscosity of Polypropylene above the Melting Temperature
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The increasing use of polymeric materials in the daily life, leads to challenges in the processing industry to deliver high performance materials with affordable terms. However, new processing techniques lead to high costs. In order to reduce processing costs it is necessary to understand the non-Newtonian behavior of the polymers in their molten state to be able to simulate the processes before the construction of the plants starts. Here the shear thinning behavior of the viscosity of polymeric melts is essential. Thus, this paper deals with the experimental investigation of the thermo-rheological behavior of the viscosity of one of the most used polymers (Polypropylene) over a wide range of temperatures and shear rates.  Furthermo

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Publication Date
Sun Jun 30 2002
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Determination of Surface Diffusion Coefficient for Adsorption Process
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Publication Date
Sat Apr 01 2023
Journal Name
Journal Of Engineering
Effect of Surface Pavement Type on Traffic Noise
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This paper investigates the issue of surface-type effects on traffic noise in Baghdad. Since the raw materials for both flexible and rigid paving are available from local sources, the decision on selecting the type of paving which depends on the budget of the project and the road's importance and function. Knowing that for high traffic volumes and a high percentage of heavy vehicles, rigid pavement is more suitable compared to flexible pavement. In Baghdad, some highways consist of flexible pavement and others of combined pavement (flexible segments and rigid segments), so the study of the effect of surface type on traffic noise becomes an important matter. This study selected three highways: one with flexible pavement a

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