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Comparison of Shear Bond Strength of Sapphire Bracket Bonded to Zirconium Surface after Using Different Surface Conditioning Methods (In Vitro Study)
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Background: The present study was carried out to compare shear bond strength of sapphire bracket bonded to zirconium surface after using different methods of surface conditioning and assessment of the adhesive remnant index. Materials and methods: The sample composed of 40 zirconium specimens divided into four groups; the first group was the control, the second group was conditioned by sandblast with aluminum oxide particle 50 μm, the third and fourth group was treated by (Nd: YAG) laser (1064nm)(0.888 Watt for 5 seconds) for the 1st laser group and (0.444 Watt for 10 seconds) for the 2nd laser group. All samples were coated by z-prime plus primer. A central incisor sapphire bracket was bonded to all samples with light cure adhesive resin. Shear bond strength was measured by using Tinius Olsen universal testing machine. After debonding, each bracket and zirconium surface were examined and adhesive remnant index was registered. The difference in shear bond strength among groups was analyzed by using ANOVA test. The adhesive remnant index was assessed using Chi-square test. Results: The 2nd laser group had the highest mean value of shear bond strength then the 1st laser group followed by the sandblasting group, while the control group had the least value, non-significant difference in the shear bond strength was found between the laser groups and highly significant difference was found between all other comparable groups. Non-significant difference in the site of bond failure was found between the laser groups and sandblasting group, and between the two laser groups. Conclusion: The laser conditioning method showed higher value of shear bond strength than the sandblasting conditioning method.

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Publication Date
Mon Jun 30 2025
Journal Name
Madenat Al-elem University College
The Ripple Effect of Plastic Pollution: Environmental and Public Health Perspectives: A review
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Abstract: Plastic pollution is a major issue of the current century. This waste is found in seas, freshwater, lakes, rivers, coastal areas, and soil. In this article, this article discusses the various sources of plastic pollution, including the manufacturing process of plastics and the addition of materials to improve their properties, as well as the use of single-use plastics that are not recyclable, in addition to burning and illegal waste disposal in the open. The impact on public health is through human exposure to toxins from plastics in the environment directly through inhaling dust and fumes, consuming contaminated food and drink, and skin contact. Indirectly, when marine creatures consume microplastics, they will find their way

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Publication Date
Thu Mar 01 2018
Journal Name
2018 Tenth International Conference On Advanced Computational Intelligence (icaci)
On high-level control of power-augmentation lower extremity exoskeletons: Human walking intention
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Publication Date
Tue Oct 02 2018
Journal Name
Iraqi Journal Of Physics
The efficiency calibration for local manufacturing gamma scanning systems of radioactive waste drums
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The Local manufacturing scanning gamma system designed in Tuwaitha site for nondestructive assay method of radioactive waste drums, where it consist of two main parts with their belongings for controlling the of detector and drum movements up-down and rotation respectively. The volume of the used drum is 220 L with 85 cm height. The drum filled with Portland cement. Six cylindrical holes were made within cement drum and distributed in radial arrangement.The152Eu source inserted in these holes individually, to measure the average angular count rate of gamma radiation. The full energy efficiency value for geometry of drum and detector is computed for thirteen photo peaks. The average efficiency represented by the curve of these peaks indic

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Publication Date
Mon Mar 01 2021
Journal Name
Iraqi Journal Of Physics
Antibacterial and morphological properties of polypyrrole/silver nanocomposites synthesized by chemical oxidative polymerization
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Polypyrrole/silver (PPy/Ag) nanocomposites was synthesized via a chemical oxidative method. The AFM analysis is performed to study the surface roughness, morphology and size distribution of the PPy particles and PPy-ag nanocomposites. The results indicated that as the concentration of Ag in the nanocomposite increases, the roughness also increases. The size of nanoparticles was also evaluated and found in the range of 15 nm to 125 nm. The PPy/Ag nanocomposites exhibited an effectiveness against Gram-negative Escherichia coli showing an inhibition zone of 4mm and displayed poor efficacy against Gram-positive Staphylococcus aureus. Based on given adequate antibacterial characteristics of PPy/Ag nanocomposites, it can be identified as a pro

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Publication Date
Tue Oct 02 2018
Journal Name
Iraqi Journal Of Physics
Gas sensitivity properties of TiO2/Ag nanocomposite films prepared by pulse laser deposition
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In this study, a double frequency Q-switching Nd:YAG laser beam (1064 nm and λ= 532 nm, repetition rate 6 Hz and the pulse duration 10ns) have been used, to deposit TiO2 pure and nanocomposites thin films with noble metal (Ag) at various concentration ratios of (0, 10, 20, 30, 40 and 50 wt.%) on glass and p-Si wafer (111) substrates using Pulse Laser Deposition (PLD) technique. Many growth parameters have been considered to specify the optimum condition, namely substrate temperature (300˚C), oxygen pressure (2.8×10-4 mbar), laser energy (700) mJ and the number of laser shots was 400 pulses with thickness of about 170 nm. The surface morphology of the thin films has been studied by using atomic force microscopes (AFM). The Root Mean Sq

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Publication Date
Fri Jan 01 2021
Journal Name
Journal Of Engineering
Design of a PID-Lead Compensator for a Twin Rotor Aerodynamic System (TRAS)
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This paper deals with a Twin Rotor Aerodynamic System (TRAS). It is a Multi-Input Multi-Output (MIMO) system with high crosscoupling between its two channels. It proposes a hybrid design procedure that combines frequency response and root locus approaches. The proposed controller is designated as PID-Lead Compensator (PIDLC); the PID controller was designed in previous work using frequency response design specifications, while the lead compensator is proposed in this paper and is designed using the root locus method. A general explicit formula for angle computations in any of the four quadrants is also given. The lead compensator is designed by shifting the dominant closed-loop poles slightly to the left in the s-plane. This has the effect

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Publication Date
Wed May 29 2019
Journal Name
Iraqi Journal Of Physics
Weathering effects on the thermal conductivity of PS/PMMA blends for packaging application
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This work describes the weathering effects (UV-Irradiation, and Rain) on the thermal conductivity of PS, PMMA, PS/PMMA blend for packaging application. The samples were prepared by cast method at different ratios (10, 30, 50, 70, and 90 %wt). It was seen that the thermal conductivity of PMMA (0.145 W/m.K), and for PS(0.095 W/m.K), which increases by PS ratio increase up to 50% PS/PMMA blend then decreased that was attributed to increase in miscibility of the blend involved. By UV-weathering, it was seen that thermal conductivity for PMMA increased with UV-weathering up to (30hr) then decreased, that was attributed to rigidity and defect formation, respectively. For 30%PS/PMMA, there results showed unsystematic decrease in thermal conduct

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Publication Date
Fri May 20 2016
Journal Name
Journal Of Biodiversity And Environmental Sciences Jbes
New record of the Epaulet Skimmer: Orthetrum chrisostigma (Burmeister) (Odonata: Libellulidae) from Iraq
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Publication Date
Sun May 10 2015
Journal Name
Al-academy
Performing processors of view between impressionism & superrealism (A comparative analysis): فريد خالد علوان
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Addressed the problem of the research is marked: (Performing processors for the time between Impressionism and superrealism) the concept of time and how to submit artwork. The search came in four sections: general framework for research and identified the research problem and the need for him. With an indication of the importance of his presence. Then determine the research objectives of (detection processors performing to the concept of time in works of art in each of Impressionism and superrealism. And a comparison between them to reveal similarities and differences), followed by the establishment of boundaries Find three (objectivity, the temporal and spatial) were then determine the terms related to the title. Then provide the theore

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Publication Date
Sun Jan 01 2023
Journal Name
2nd International Conference On Mathematical Techniques And Applications: Icmta2021
Antimicrobial activities of some new heterocyclic compounds bearing imidazo[2,1-b]benzothiazole moiety
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