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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
Wed Dec 02 2020
Journal Name
Iraqi Journal Of Applied Physics
Characterization of Multilayer Highly-Pure Metal Oxide Structures Prepared by DC Reactive Magnetron Sputtering Technique
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In this work, multilayer nanostructures were prepared from two metal oxide thin films by dc reactive magnetron sputtering technique. These metal oxide were nickel oxide (NiO) and titanium dioxide (TiO2). The prepared nanostructures showed high structural purity as confirmed by the spectroscopic and structural characterization tests, mainly FTIR, XRD and EDX. This feature may be attributed to the fine control of operation parameters of dc reactive magnetron sputtering system as well as the preparation conditions using the same system. The nanostructures prepared in this work can be successfully used for the fabrication of nanodevices for photonics and optoelectronics requiring highly-pure nanomaterials.

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Publication Date
Sat Jan 01 2022
Journal Name
3rd International Scientific Conference Of Alkafeel University (iscku 2021)
Prevalence of Entamoeba histolytica among enteric infection in Al-Furat general hospital in Baghdad/Iraq
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Publication Date
Fri Apr 27 2018
Journal Name
Journal Of Periodontal Research
Potential role of periodontal pathogens in compromising epithelial barrier function by inducing epithelial‐mesenchymal transition
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Background and Objective

Epithelial‐mesenchymal transition (EMT) is a process by which epithelial cells acquire a mesenchymal‐like phenotype and this may be induced by exposure to gram‐negative bacteria. It has been proposed that EMT is responsible for compromising epithelial barrier function in the pathogenesis of several diseases. However, the possible role of EMT in the pathogenesis of periodontitis has not previously been investigated. The aim of this study therefore was to investigate whether gram‐negati

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Publication Date
Mon May 01 2023
Journal Name
Ain Shams Engineering Journal
Neural network modeling of rutting performance for sustainable asphalt mixtures modified by industrial waste alumina
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Publication Date
Wed Mar 15 2023
Journal Name
Bionatura
Immune-protective effect of topical paquinimod administration against imiquimod-induced psoriasis-like inflammation in mice
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Psoriasis is a chronic, inflammatory condition that primarily affects the skin, hair, and joints and is associated with significant humanistic and economic consequences. This work induced psoriasis in mice using an imiquimod 5% cream, an immune response modifier that can cause psoriasis-like skin inflammation when given orally. Paquinimod is prepared as an ointment and has been topically given to mice before imiquimod application. In this study, albino mice were allocated into five groups and treated as follows: the control group received only a daily application of cream based on shaved back (62.5mg/2cm) with a daily topical dose of ointment for 14 consecutive days with the oral vehicle. The Imiquimod group received a daily topical

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Publication Date
Mon Jun 05 2023
Journal Name
Journal Of Engineering
Serviceability behavior of High Strength Concrete I-beams reinforced with Carbon Fiber Reinforced Polymer bars
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Fiber Reinforced Polymer (FRP) bars are anisotropic in nature and have high tensile strength in the fiber direction. The use of High-Strength Concrete (HSC) allows for better use of the high-strength properties of FRP bars. The mechanical properties of FRP bars can yield to large crack widths and deflections. As a result, the design of concrete elements reinforced with FRP materials is often governed by the Serviceability Limit States (SLS). This study investigates the short-term serviceability behavior of FRP RC I-beams. Eight RC I-beams reinforced with carbon-FRP (CFRP) and four steel RC I-beams, for comparison purposes, were tested under two-point loading.
Deformations on the concrete and crack widths and spacing are measured and

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Publication Date
Fri Dec 15 2023
Journal Name
Iraqi Journal Of Laser
Numerical Simulation of Metasurface Grating to Function as Polarization Modulator in Quantum Key Distribution Systems
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larization modulation plays an important role in polarization encoding in quantum key distribution. By using polarization modulation, quantum key distribution systems become more compact and more vulnerable as one laser source is used instead of using multiple laser sources that may cause side-channel attacks. Metasurfaces with their exceptional optical properties have led to the development of versatile ultrathin optical devices. They are made up of planar arrays of resonant or nearly resonant subwavelength pieces and provide complete control over reflected and transmitted electromagnetic waves opening several possibilities for the development of innovative optical components. In this work, the Si nanowire metasurface

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Publication Date
Sat Jan 01 2011
Journal Name
Journal Of Engineering
ORGANIZATION OF MEMORY CHIPS IN MEMORY SYSTEMS THAT HAVE WORD SIZE WIDER THAN 8-BIT
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This paper presents a method to organize memory chips when they are used to build memory systems that have word size wider than 8-bit. Most memory chips have 8-bit word size. When the memory system has to be built from several memory chips of various sizes, this method gives all possible organizations of these chips in the memory system. This paper also suggests a precise definition of the term “memory bank” that is usually used in memory systems. Finally, an illustrative design problem was taken to illustrate the presented method practically.

Publication Date
Sat Jan 01 2022
Journal Name
International Journal Of Differential Equations
Dynamical Behaviours of Stage-Structured Fractional-Order Prey-Predator Model with Crowley-Martin Functional Response
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In this paper, the dynamic behaviour of the stage-structure prey-predator fractional-order derivative system is considered and discussed. In this model, the Crowley–Martin functional response describes the interaction between mature preys with a predator.  e existence, uniqueness, non-negativity, and the boundedness of solutions are proved. All possible equilibrium points of this system are investigated.  e su‰cient conditions of local stability of equilibrium points for the considered system are determined. Finally, numerical simulation results are carried out to con‹rm the theoretical results.

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Publication Date
Sat Jan 01 2011
Journal Name
Iraqi Journal Of Physics
Calculation of Particle Emission Rates for Nucleon-Induced Reactions with non-Equidistance Spacing Model Dependence
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Nuclear emission rates for nucleon-induced reactions are theoretically calculated based on the one-component exciton model that uses state density with non-Equidistance Spacing Model (non-ESM). Fair comparison is made from different state density values that assumed various degrees of approximation formulae, beside the zeroth-order formula corresponding to the ESM. Calculations were made for 96Mo nucleus subjected to (N,N) reaction at Emax=50 MeV. The results showed that the non-ESM treatment for the state density will significantly improve the emission rates calculated for various exciton configurations. Three terms might suffice a proper calculation, but the results kept changing even for ten terms. However, five terms is found to give

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