Purpose: To evaluate the effect of different surface treatments on shear bond strength between dentin and IPS e.max lithium disilicate glass-ceramic. Materials and Methods: Eighteen extracted third molars were embeded in epoxy resin. The tooth was sectioned vertically in mesiodistal direction using a low speed hard tissue microtome. The buccal and lingual surfaces of each section were ground flat using 600 grit Silicone carbide paper. Eighteen ceramic discs consisted of lithium disilicate glass-ceramic were prepared with a diameter of 4.7mm and height of 2.2mm. The discs were divided in two groups (n=10): (1) IPS e.max treated with hydrofluoric acid and Monobond Plus (MBP) and (2) IPS e.max treated with Monobond Etch &Prime (MBEP). The tooth was cemented with Multilink Automix and stored for 24hours at room temperature before thermocycling and subsequently loaded to failure in Universal Testing Machine. Failure mode were recorded for each specimen. Result: Bond strength analysis and t-test analysis MBEP demonstrated the higher shear bond strength (SBS). MBP and MBEP showed no statistically significant difference were found between them. One-way ANOVA and t-test was used to determine differences in bond strength within and between the groups. Cohesive failure in resin cement was predominant with higher results while adhesive and mixed with lower and equal. Conclusion: Surface treatment with Monobond Etch and Prime has a favorable effect on SBS between dentin and lithium disilicate glass-ceramic with resin cement compared with Monobond Plus.
Thin films samples of Bismuth sulfide Bi2S3 had deposited on
glass substrate using thermal evaporation method by chemical
method under vacuum of 10-5 Toor. XRD and AFM were used to
check the structure and morphology of the Bi2S3 thin films. The
results showed that the films with law thickness <700 nm were free
from any diffraction peaks refer to amorphous structure while films
with thickness≥700 nm was polycrystalline. The roughness decreases
while average grain size increases with the increase of thickness. The
A.C conductivity as function of frequency had studied in the
frequency range (50 to 5x106 Hz). The dielectric constant,
polarizability showed significant dependence upon the variation of
thic
The experiment was conducted under shading (with the aid of Saran) condition on a nursery managed by the Baghdad Mayoralty during the season of 2014-2015 to study the effect of composed sheep manure extract on the growth and leaf nutrients content of tomato seedlings var. Wijdan. The experiment was composed of 6 treatments included the extract of sheep manure by hot (425C)and lmbient(205C) temperature water .The extract was diluted to the half by water and foliar applied to seedlings (multible application) or to the soil . Treatments also included the application of NPK chemical fertilizers as recommended and a control treatment through applying distilled water as foliar .The experiment was designed according to the randomized compl
... Show MoreOne of the most important challenges facing the development of laser weapons is represented by the attenuation of the laser beam as it passed through the layers of atmosphere.This paper presents a theoretical study to simulate the effect of turbulence attenuation and calculates the decrease of laser power in Iraq. The refractive index structure C_n^2 is very important parameter to measure the strength of the atmospheric turbulence, which is affected by microclimate conditions, propagation path, season and time in the day. The results of measurements and predictions are based on the Kolmogorov turbulence theory. It was demonstrated by simulations that the laser weapons in Iraq were severely affected due to the large change in temperatures,
... Show MoreIn this paper the effect of thermal annealing on the structural and optical properties of Antimony Selenide (Sb2Se3) is investigated. Sb2Se3 powder is evaporated on clean amorphous glass substrates at room temperature under high vacuum pressure (4.5×10-6 mbar) to form thin films. The structural investigation was done with the aid of X-ray diffraction (XRD) and atomic force microscopy (AFM). The amorphous to polycrystalline transformation of these thin films was shown by X-ray diffraction analysis after thermal annealing. These films' morphology is explained. (UV-Vis ) spectra in ranges from 300 to 1100 nm was used to examine the optical properties of the films .The absorption coefficient and optical energy gap of the investigated films are
... Show MoreThis work consists of a numerical simulation to predict the velocity and temperature distributions, and an experimental work to visualize the air flow in a room model. The numerical work is based on non-isothermal, incompressible, three dimensional, k turbulence model, and solved using a computational fluid dynamic (CFD) approach, involving finite volume technique to solve continuity, momentum and energy equations, that governs the room’s turbulent flow domain. The experimental study was performed using (1/5) scaled room model of the actual dimensions of the room to simulate room air flow and visualize the flow pattern using smoke generated from burnt herbs and collected in a smoke generator to delivered through
... Show MoreIn this work, an optical fiber biomedical sensor for detecting the ratio of the hemoglobin in the blood is presented. A surface plasmon resonance (SPR)-based coreless optical fiber was developed and implemented using single- and multi-mode optical fibers. The sensor is also utilized to evaluate refractive indices and concentrations of hemoglobin in blood samples, with 40 nm thickness of (20 nm Au and 20 nm Ag) to increase the sensitivity. It is found in practice that when the sensitive refractive index increases, the resonant wavelength increases due to the decrease in energy.
Thirty swabes of medical implants were collected from Al-Yarmouk's hospital which were cultured on manitole agar to isolate Staphelococcus aureus . Only four samples gave positive results with this media. It was used ten types of antibiotics to test the sensitivity of this bacterium against them. All isolates of S. aureus were recorded as multidrug resistant and were considered as MRSA. One pledge alternative therapy is the utilize of certain pure bacterocin MIC (32.5 to 62.5 μg/ml) and it was compared with vancomycin (200-400 μg/ml) with average of (8 – 15) mm diameter of inhibition zones recpectively. The first reduction of biofilm formation ability has been proved in catheters when treatedby pure bacterocin. The test shows the highes
... Show MoreThis study aims to investigate the features of stellar-gaseous kinematics and dynamics mass using scaling coefficient relationships (such as the Faber–Jackson relation (FJR)) of two samples of elliptical and lenticular galaxies. These two samples of 80 ellipticals and 97 lenticulars were selected from previous literature works. The Statistical Package for Social Sciences )SPSS( and Matrix Laboratory (MATLAB) program were used to find out the associations of multiple factors under investigation such as main kinematic properties of the gaseous-stellar (effective radius Re, surface density within the effective radius (Ʃeff) , stellar mass in the blue band (Mstar (B)), gas mass ( Mgas), dynamic (Mdyn) and baryonic (Mbar), supermassiv
... Show MorePostmodern arguments, formed a critic case of what modernity brought in several levels. Postmodern practice was considered as a proactive case having amorphous concepts and features to what entiled as an intellectual trends postmodern philosophically and intellectually. But, what postmodernism architecture broughts in it essence, was not isolation from the intellectual context and entrepreneurship case, and it was not disconnecting from the intellectual and philosophical era of that period. Lliteratures and philosophical argument precede what (Robert Venturi) and (Charles A Jencks) had brought, albeit it was closer to critics and correction the path of modernity from crystallizing a direction that exceeds modrinity to wh
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