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An evaluation of an Iraqi phosphate-bonded investment and a commercial type on the marginal fit of ceramometalcopings using three different investing and burnout techniques
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Background: The accuracy of fitness of any dental casting is imperative for the success of any prosthodontic treatment. From the time that dental casting was first introduced, efforts have been made to produce more accurate and better fitted castings with minimal marginal discrepancy. The aim of this in vitro study was to evaluate the effects of three different investing and burnout techniques on the vertical marginal discrepancies ofceramometalcopings invested with two types of phosphate- bonded investments. Materials and methods: Sixty wax patterns were fabricated on a standardized prepared brass die representing an upper central incisor by the aid of a custom-made split mold. Three different investing and burnout techniques were applied for an Iraqi investment and a commercial type; Group I:Ring investing with conventional burnout technique (RC);Group II: Ringless investing with conventional burnout technique (RLC);Group III: Ring investing with accelerated burnout technique (RA).Twenty wax patterns of each group were divided into two subgroups according to the type of investment material used (10 for each subgroup) represented as (B) for the BellaStar XL and (W) for the WYMvest investments. Complete castings were finished and seated on the metal die. The accuracy of fit of each coping was determined by measuring the vertical marginal discrepancies between the finish line on the metal die and the margins of each coping at four specific reference points on the labial, mesial, palatal, and distal aspects of the die by the aid of a light microscope supplied with a digital camera.The arithmetic mean of each three records was computed and regarded as the amount of the marginal discrepancy of each coping and was used as a unit for the statistical analysis. Results: Mean marginal accuracy for W(RLC)was found to be the least (13.839+4.5724 um) while the highest mean value related to B(RLC) (29.033+2.102 um). In general, ANOVA test showed significant results among the mean values of the Binvestment subgroups while LSD test showed non-significance between the (RA) and both the (RC) and (RLC) subgroups. On the other hand, significance was present between the (RLC) and (RA)of the Winvestment subgroups while non-significance was located between the (RC) and both the (RLC) and (RA) subgroups. Comparing similar subgroups of the two tested investments, the Student's t-test showed non-significance between the (RC) subgroups while high significance was located between the (RLC) and (RA) subgroups respectively.Concerning the vertical marginal discrepancy of the copings, applying the (RC) technique for both investments caused non-statistical significance between the labial, mesial, palatal, and distal aspects.The (RLC) technique caused high significance between the four aspects, while the (RA) technique caused non-significance between the labial aspect only and the others. Conclusion: The Iraqi investment generally produced less vertical marginal discrepancies (using the three different investing and burn-out techniques) than the commercial investment.In order to achieve a better marginal fit, it seems that ceramometalcopings invested with the commercial investment tested are better be cast using the conventional ring investing and burnout technique.

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Publication Date
Thu May 18 2023
Journal Name
College Of Islamic Sciences
Consider speech science in light of its purposes
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Considering the science of speech in the light of its purposes is an accurate scientific study that looks at it from its reality in which it originated, and its topic that it dealt with and its goals that it sought, and it follows its main course in the directions of approving the belief and inferring it, and repelling the objections to it, and this study comes to show the realism of the science of speech in its emergence Its subject and method, since its launch was from the reality of the Islamic nation and based on its intellectual needs, so its presence was necessary in the life of the Islamic nation because of its role in facing the challenges faced by the Islamic faith, and the dangers it was exposed to as a result of the intellectu

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Publication Date
Thu Feb 07 2019
Journal Name
Iraqi Journal Of Laser
Design High Efficient Reflectivity of Distributed Bragg Reflectors
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Bragg Reflectors consist of periodic dielectric layers having an optical path length of quarter wavelength for each layer giving them important properties and makes them suitable for optoelectronics applications. The reflectivity can be increased by increasing the number of layers of the mirror to get the required value. For example for an 8 layers Bragg mirror (two layers for each dielectric pair), the contrast of the refractive index has to be equal to 0.275 for reaching reflectivity > 99%. Doubling the number of layers results in a reflectivity of 99.99%. The high reflectivity is purely caused by multiple-interference effects. It can be analyzed by using different matrix methods such as the transfer matrix method (TMM) which is the

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Publication Date
Sat Apr 01 2023
Journal Name
Baghdad Science Journal
Coincidence of Fixed Points with Mixed Monotone Property
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The purpose of this paper is to introduce and prove some coupled coincidence fixed point theorems for self mappings satisfying -contractive condition with rational expressions on complete partially ordered metric spaces involving altering distance functions with mixed monotone property of the mapping. Our results improve and unify a multitude of coupled fixed point theorems and generalize some recent results in partially ordered metric space. An example is given to show the validity of our main result. 

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Publication Date
Sat Sep 01 2018
Journal Name
Ulustath
Critical Discourse Analysis of Donald Trump's Inaugural Speech
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       Political speeches are represented in different shapes as political forum, events or as inaugural speech. This research critically analyzes the inaugural Speech of the President Donald Trump which was delivered on 20th ,January, 2017 from the site<www.cnn.com> retrieved on 10th ,May,2017. The objectives of the study are: First: classifying and discussing well known micro structures (linguistic feature) of the speech, and second: classifying the macro structures i.e. the delivered political inaugural speech  in which he includes social structures. To reach to the objectives of the study, the researcher will adopt Norman Fairclough’s three dimensional Analytical Model(1989). Tracing the model, the speech was subm

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Publication Date
Tue Jan 31 2017
Journal Name
Journal Of Engineering
Remediation of Contaminated Soil with Petroleum Industrial Wastewater
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The contamination of soil with the wastes of oil industry products that are complex mixtures of hydrocarbons increased recently due to the large development of oil industries in Iraq. This study deals with the remediation of low permeability contaminated clayey soil by using the enhanced electrokinetic technique (EK). The contaminated soil samples obtained from Thi-Qar oil refinery plant in Al-Nassyriah city, where the byproducts of refinery plant are disposed into that site. The byproduct contaminant treated as total petroleum hydrocarbons (TPH) to avoid dealing and complexity of treating the individual minerals and compounds consisting the contaminant. The initial concentrations of TPH were (702.7, 1168, 1235) ppm in the contaminated s

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Publication Date
Sun Jan 14 2018
Journal Name
Journal Of Engineering
Direct Shear Behavior of Fiber Reinforced Concrete Elements
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Improving the accuracy of load-deformation behavior, failure mode, and ultimate load capacity for reinforced concrete members subjected to in-plane loadings such as corbels, wall to foundation connections and panels need shear strength behavior to be included. Shear design in reinforced concrete structures depends on crack width, crack slippage and roughness of the surface of cracks.

This paper illustrates results of an experimental investigation conducted to investigate the direct shear strength of fiber normal strength concrete (NSC) and reactive powder concrete (RPC). The tests were performed along a pre-selected shear plane in concrete members named push-off specimens. The effectiveness of concrete compressiv

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Publication Date
Sat Dec 01 2012
Journal Name
Iraqi Journal Of Physics
Fabrication of carbon nanopowder by arc discharge technique
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Carbon Nanopowder was fabricated by arc discharge technique at deposition pressure of 10-5 mbar Argon gas on glass substrates. The prepared carbon nano- powder was collected from chamber and purified with nitric acid at 323K .The morphology and crystalline structure of the prepared powder was examined by X-Ray Diffraction (XRD), Atomic Force Microscope (AFM), and Scanning Electron Microscope (SEM). XRD spectrums showed that the powder exhibits amorphous structure and after purification, the powder showed hexagonal structure with a preferential orientation along(002) direction ,where AFM and SEM gave very compatible estimation on the grain size and shape of the nanopowder.

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Publication Date
Thu Oct 31 2024
Journal Name
Archive Of Mechanical Engineering
Computational analysis of SD7037 airfoil with plain flap
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The impact of a simple trailing-edge plain flap on the aerodynamics of the SD7037 airfoil have been studied in this paper using computational fluid dynamics at Reynolds number of 3×105 across various low angles of attack and flap deflection angles. The computational model was evaluated by using Star CCM+ software with κ--ω SST turbulence and gamma transition model to solve Navier-Stokes equations. The accuracy of the computational model has been confirmed through comparison with experimental data, showing a high level of agreement at low angles of attack. The findings revealed that specific combinations of angles of attack and flap deflection angles could increase the lift-to-drag ratio by over 70% compared to baseline conditions, benefi

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Publication Date
Tue Jun 14 2016
Journal Name
Al-academy
Recruitment of Arabic calligraphy in gold jewelry styles
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Search came (the employment of Arabic calligraphy in gold jewelry styles) four chapters, the first chapter of which dealt:A/research problem B/importance of research C/targets search D/ Define termsAs the aim of the research (to identify the employment of different forms of Arabic calligraphy on gold jewelry styles).It came in the second quarter (the theoretical framework and previous studies), some of the topics reviewed in which diversities researcher aesthetic and functional, and various uses that filled Arabic calligraphy.The third chapter outlining the researcher methodology and the research community, has a special form for the analysis of the samples are designed as form is offered on a number of experts in the field of jurisdicti

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Publication Date
Tue Dec 19 2023
Journal Name
Bulletin Of The Iraq Natural History Museum
CHECKLIST OF DARKLING BEETLES (COLEOPTERA, TENEBRIONIDAE) IN IRAQ
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In the current review, an updated list of dark beetle species (Coleoptera, Tenebrionidae) recorded in Iraq was given. The current paper is based on previous studies in the literature and contains all dark beetles referred to in Iraq, except for the species within the Pimelinae subfamily. The investigation of this review showed the presence of 89 species belonging to 34 genera within five subfamilies. This work included mentioning the basionyms and synonyms for genera and species with their global distribution, as well as, correcting the scientific names that were mentioned in the previous checklists.

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