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Early and delayed effect of 2% chlorhexidine on the shear bond strength of composite restorative material to dentin using a total etch adhesive
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Background: Lack of durability of the bond of the dental adhesive systems to tooth structure is one of the most important problems in tooth colored restorative work. This in vitro study was performed to evaluate the effect of 2% chlorhexidine gluconate(CHX) on dentin bond strength by using total etch adhesive system at twenty-four hours and three months of water storage. Material and methods:A flat dentin surface was prepared for forty sound human maxillary premolar teeth which were acid etched with 36% phosphoric acid gel after being divided randomly into four groups of ten teeth each according to storage time and CHX application, theCHX was applied for 60 seconds before adhesive application for groups I and III which were tested after twenty-four hours and three months respectively, while the distal water was applied for 60 seconds before the application of adhesive for group II and IV which were tested after twenty-four hours and three months respectively.The Prime and Bond® NT™ adhesive (Dentsply) was applied and cured, Composite (Ceram X mono, Dentisply) was applied through special mold with 2 mm thickness and light cured, Then all specimens were stored in distilled water 37oC until the time of testing of each group.Shear bond strength test was performed at the end of the storage period (24 hours or 3 months). Results:T-test results showed high statistically significant reduction in shear bond strength (SBS) in non CHX group IV (tested after 3 months) compared to non CHX group II (tested after 24 hours)(P< 0.01). In CHX groups I (tested after 24 hours) and III (tested after 3 months), results showed no statistically significant differences in shear bond strength(p> 0.05).On the other hand result showed statistically no significant differences between groups I and II in 24 hours shear bond strength (P> 0.05). After 3 months water storage, there was statistically high significant differences between the groups III and IV (P< 0.01). Conclusion: the use of 2 % CHX glocounate solution after acid etching and before bonding of dentin have no adverse effect on immediate bond strength (24 hours storage), and was effective in reducing degradation of resin-dentin bond interface after three months of water storage.

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Publication Date
Sun Sep 03 2017
Journal Name
Baghdad Science Journal
Kinetic and Mechanistic Studies for the Gas-phase Reaction of Ozone with 2, 3-Dimethyl-2-Butene and 1, 3-Butadiene
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The reactions of ozone with 2,3-Dimethyl-2-Butene (CH3)2C=C(CH3)2 and 1,3-Butadiene CH2=CHCH=CH2 have been investigated under atmospheric conditions at 298±3K in air using both relative and absolute rate techniques, and the measured rate coefficients are found to be in good agreement in both techniques used. The obtained results show the addition of ozone to the double bond in these compounds and how it acts as function of the methyl group substituent situated on the double bond. The yields of all the main products have been determined using FTIR and GC-FID and the product studies of these reactions establish a very good idea for the decomposition pathways for the primary formed compounds (ozonides) and give a good information for the effe

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Publication Date
Sun May 28 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
On-Line Navigational Problem of a Mobile Robot Using Genetic Algorithm
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  Manufacturing systems of the future foresee the use of intelligent vehicles, optimizing and navigating. The navigational problem is an important and challenging problem in the field of robotics. The robots often find themselves in a situation where they must find a trajectory to another position in their environment, subject to constraints posed by obstacles and the capabilities of the robot itself. On-line navigation is a set of algorithms that plans and executes a trajectory at the same time.         The system adopted in this research searches for a robot collision-free trajectory in a dynamic environment in which obstacles can move while the robot was moving toward the target. So, the ro

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Publication Date
Sun May 28 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Science
On-Line Navigational Problem of a Mobile Robot Using Genetic Algorithm
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Publication Date
Wed Mar 06 2002
Journal Name
Journal Of Engineering
The effect of technology on interior space
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Publication Date
Wed May 15 2019
Journal Name
Al-khwarizmi Engineering Journal
Mesoporous Silica MCM-41 as a Carriers Material for Nystatine Drug in Delivery System
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In the present study, MCM-41 was synthesis as a carrier for poorly drugs soluble in water, by the sol-gel technique. Textural and chemical characterizations of MCM-41 were carried out by X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscope (SEM), and thermal gravimetric analysis (TGA). The experimental results were analyzed mesoporous carriers MCM-41. With maximum drug loading efficiency in MCM-41 determined to be 90.74%. The NYS released was prudently studied in simulated body fluid (SBF) pH 7.4 and the results proved that the release of NYS from MCM-41 was (87.79%) after 18 hr. The data of NYS released was found to be submitted a Weibull model with a correlation coefficient of (0.995). The Historical

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Publication Date
Wed Jan 25 2023
Journal Name
Molecular Simulation
Engineering promising A-π-D type molecules for efficient organic-based material solar cells
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Within this work, to promote the efficiency of organic-based solar cells, a series of novel A-π-D type small molecules were scrutinised. The acceptors which we designed had a moiety of N, N-dimethylaniline as the donor and catechol moiety as the acceptor linked through various conjugated π-linkers. We performed DFT (B3LYP) as well as TD-DFT (CAM-B3LYP) computations using 6-31G (d,p) for scrutinising the impact of various π-linkers upon optoelectronic characteristics, stability, and rate of charge transport. In comparison with the reference molecule, various π-linkers led to a smaller HOMO–LUMO energy gap. Compared to the reference molecule, there was a considerable red shift in the molecules under study (A1–A4). Therefore, based on

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Publication Date
Thu Aug 01 2019
Journal Name
Journal Of Economics And Administrative Sciences
Factors that Effect on the Level of Accounting Conservatism A sample study Of insurance companies which listed on the Amman Stock Exchange (2005-2016)
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This study aimed to measure  the accounting conservatism  and the lemited factors which  affected on it in the annual financial reports of insurance companies which listed on the Amman Stock Exchange during the period from 2005 to 2016, these factors were represented by firm age, firm debt and firm size.

Using the market value model (MV) To book value  ( BV) Beaver and Ryan (2000) The level of the accounting conservatism was measured. The study found that the insurance companies which are listed on the ASE exercise the accounting conservatism when they were  preparing financial reports. And when conducting a process  of the test of the affected of the factors (The age of the

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Publication Date
Thu Mar 16 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Optical Properties of PVA/K2CrO4 Composite
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     The change in the optical properties for samples of pure PVA and PVA /K2CrO4composite have been studied .The samples were prepared with different percentage (1,3,5,and 7)%wt of K2CrO4 by casting method technique .In this work ,we are study the absorption ,reflectance spectra ,absorption  coefficient, energy gap ,extinction coefficient ,and transmittance spectra as a function of wavelength range (200-800)nm ,Also  real and imaginary part of dielectric constant have been studied in the range of wave length .The results exhibit the optical properties change by the increase of K2CrO4 concentration, and the values of energy gap for indirect transitions decrease by the increase of the concentration of  K2CrO4

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Publication Date
Thu Mar 01 2018
Journal Name
Journal Of Engineering
Analysis of Double Skin Composite Slabs
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This paper deals with finite element modeling of the ultimate load behavior of double skin composite (DSC) slabs. In a DSC slab, shear connectors in the form of nut bolt technique studs are used to transfer shear between the outer skin made of steel plates and the concrete core. The current study is based on finite element analysis using ANSYS Version 11 APDL release computer program. Experimental programmes were carried out by the others, two simply supported DSC beams were tested until failure under a concentrated load applied at the center. These test specimens were analyzed by the finite element method and the analyses have shown that these slabs displayed a high degree of flexural characteristics, ultimate strength,

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Publication Date
Wed Jan 16 2019
Journal Name
Applied Physics A
Detecting the thermoplasmonic effect using ellipsometry parameters for self-assembled gold nanoparticles within a polydimethylsiloxane matrix
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