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The influence of cavity design for cusp coverage on fracture strength of weakened maxillary first premolars using two esthetic restorative systems (CAD/CAM hybrid ceramic and nanohybrid composite) (An in vitro study)
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Background: Maxillary first premolar with wide MOD cavity more susceptible to fracture. The aim of this study was to assess the influence of cavity design for cusp coverage on the fracture resistance of weakened maxillary first premolar restored with CAD/CAM hybrid ceramic versus nanohybide composite. Materials and Methods: Fifty six intact maxillary first premolars of approximately comparable sizes were divided into seven groups eight for each: Group A: Intact teeth (control group); Group B: teeth prepared for MOD inlay; Group C: teeth prepared for MOD onlay covering the lingual cusp; Group D: teeth prepared for MOD covering buccal and lingual cusps ,the previous three groups indirectly restored with nanohybrid composite (3M ESPE Z 250 XT); Group E,F,G prepared with the same design as group B, C, D respectively and restored with CAD/CAM hybrid ceramic (VITA ENAMIC). Results: An axial compression test was used to measure the fracture strength of experimented teeth. The readings were analyzed statistically by t-test, one way ANOVA and LSD, then the mode of fracture had been examined. The results showed that sound teeth in group (A) had more fracture resistance values than all experimental groups and the difference were highly significant with group (B, E, F, G).When the influence of cavity design tested among composite groups it showed highly significant difference between group (B) and (C)and the highest fracture resistance value was for group(C), whereas the influence of cavity design among Enamic groups showed highly significant difference between group (E) and (G) the highest fracture resistance value was for group(E).T-test between similar designs showed non-significant difference between MOD groups and highly difference between other groups. Conclusions: Cusp coverage increased the fracture resistance of composite groups but result in non-restorable fracture, while Enamic total onlay presented promising fracture resistance with favorable mode of fracture. Key words: Fracture resistance, CAD/CAM, hybrid ceramic, VITA ENAMIC, nanohybrid composite, cusp coverage.

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Publication Date
Thu Jan 01 2015
Journal Name
Journal Of Engineering
Experimental Study of the effect of closed cavity wall on buildings cooling loads saving
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The experimental study showed the use of closed cavity wall (the thickness of the cavity 5cm) made a percentage reduction in the cooling load caused by heat gain from the wall by (21.5 %) compared with the conventional wall. also the thermal resistance of the closed cavity was an average (0.2 m2.oC/W).

The experimental results of the study showed that the use of closed cavity wall reduced the average temperature of the inner surface of the wall during the day, and that the reduction was an average (0.45 oC)  when compared with the conventional wall , as well as the use of closed cavity wall reduced the temperature difference range of the inner surface of the wall during the day, and that the

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Publication Date
Thu Dec 28 2023
Journal Name
Journal Européen Des Systèmes Automatisés
Design of a Hybrid Adaptive Controller for Series Elastic Actuators of Robots
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Publication Date
Sun Jan 12 2025
Journal Name
Al–bahith Al–a'alami
News Coverage in the Iraqi Electronic Press for Internal Crises: (An Analytical Study of Al-Zaman and Al-Sabah Electronic Newspapers for the period from 1/ 3/ 2013 to 31/ 3/ 2013)
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The research study focused on the need to clarify the relationship between the Websites of Iraqi Newspapers and their roles in covering the internal crises in Iraq. The selection of Iraqi websites for the newspapers Al-Zaman and Al-Sabah was adopted as one of the most important media with a wide audience; and as a model of hot news and continuous coverage of those sites since 2003 so far. As a result, this necessitated the emergence of new types of methods of editing and writing news stories related to Iraq.

Consequently, the enormous and rapidly changing amount of Iraq news, the process of preparing and creating news has become a complex industry

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Publication Date
Tue Feb 12 2019
Journal Name
Iraqi Journal Of Laser
Design and Implementation Tunable Band Pass Filter based on PCF-Air Micro-cavity FBG Fabry-Perot Resonator
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A tunable band pass filter based on fiber Bragg grating sensor using an in-fiber Mach-Zender interferometer with dual micro-cavities is presented. The micro-cavity was formed by splicing together a conventional single-mode fiber and a solid core photonic crystal fiber (SCPCF) with simple arc discharge technique. Different parameters such as arc power, length of the SCPCF and the overlap gap between samples were considered to control the fabrication process. The ellipsoidal air-cavity between the two fibers forms Fabry-Perot cavity. The diffraction loss was very low due to short cavity length. Ellipsoidal shape micro-cavities were experimentally achieved parallel to the propagation axis having dimensions of (24.92 – 62.32) μm of width

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Publication Date
Fri Mar 01 2024
Journal Name
Advances In Structural Engineering
Simulation and design model for reinforced concrete slabs with lacing systems
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Lacing reinforcement plays a critical role in the design and performance of reinforced concrete (RC) slabs by distributing the applied loads more evenly across the slab, ensuring that no specific area of the slab is overloaded. In this study, nine slabs, divided into three groups according to the investigated parameters, were meticulously designed and evaluated to study the interplay between the lacing reinforcement and other key parameters. Each slab was crafted for simple support and was subjected to both static and repeated two-point load tests. The lacing reinforcement had an angle of 45° with various tension and lacing steel. The repeated-tested specimens with lacing reinforcement experienced smaller ductility than those of s

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Publication Date
Fri Jan 01 2021
Journal Name
Materials Today: Proceedings
Influence of design anode and cathode channel on (PEMFC) fuel cell performance
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Publication Date
Sun Jan 12 2025
Journal Name
Journal Of Baghdad College Of Dentistry
The effect of ER: YAG laser on enamel resistance to caries during orthodontic treatment: An in vitro study
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Background: One common undesirable side effect of orthodontic treatment with fixed appliances is the development of incipient caries lesions around brackets, particularly in patients with poor oral hygiene. Different methods have been used to prevent demineralization; the recent effort to improve the resistance against the demineralization is by the application of lasers. Materials and method: Thirty human premolars extracted for orthodontic purposes were used to test the effect of two energy level of ER-YAG laser on enamel resistance to demineralization. The brackets were bonded on the teeth and all the labial surface excluding 2 mm area gingival to the brackets were painted with acid resistance varnish. Three groups were generated. The fi

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Publication Date
Mon May 22 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Study of the Physical and Morphological Properties of Ceramic Insulator
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In this investigation insulator ceramic body was prepared by using iraqi local materials, these are kaolin, silica sand glass, feldspar with weight percentage (45%,25%, 30%)respectively.  After the end of treating drying and milling of raw material mixing with different concentrations of sodium silicate(1%,0.7%,0.5%,0.2%,0.1%) while zinc oxide was added at fixed weight percentage.  A disc samples was prepared after compaction and then fired by sintering temperatures (1250, 1350)oC respectively.A surface morphology was studied by using optical microscope and measurements of apparent density and porosity was under taken to the sintered samples by using Archimedes method.The study showed that the microscopic images for samples sur

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Publication Date
Thu Oct 01 2015
Journal Name
Al–bahith Al–a'alami
Correspondents and Professional Standards in News Coverage (A Field Study)
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         The essence of the new work in the satellite TV channels is to provide news coverage of news that will inform the people of what is going on around them in order to increase their political, social, economic and cultural awareness and this drives them to take positions or certain behaviors on according to what the communicator in these channels wants. News and news reports are generally used as a psychological variable to influence public opinion and does not offer interestingness and information. Therefore, satellite TV channels have assumed special attention towards their correspondents desiring to achieve scoop in news coverage and to have the final word in reading events and install it

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Publication Date
Sun Dec 01 2019
Journal Name
Ieee Xplore
A Hybrid Modified Lightweight Algorithm Combined of Two Cryptography Algorithms PRESENT and Salsa20 Using Chaotic System
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Cryptography algorithms play a critical role in information technology against various attacks witnessed in the digital era. Many studies and algorithms are done to achieve security issues for information systems. The high complexity of computational operations characterizes the traditional cryptography algorithms. On the other hand, lightweight algorithms are the way to solve most of the security issues that encounter applying traditional cryptography in constrained devices. However, a symmetric cipher is widely applied for ensuring the security of data communication in constraint devices. In this study, we proposed a hybrid algorithm based on two cryptography algorithms PRESENT and Salsa20. Also, a 2D logistic map of a chaotic system is a

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