Background: Polymethyl methacrylate (PMMA) is the most commonly used material in denture fabrication. The material is far from ideal in fulfilling the mechanical requirements, like low impact and transverse strength, poor thermal conductivity. The purpose of this study was to evaluate the effect of addition a composite of surface treated Nano Aluminum oxide (Al2O3) filler and plasma treated polypropylene fiber (PP) on some properties of denture base material. Materials and methods: One hundred fifty prepared specimens were divided into 5 groups according to the tests, each group consisted of 30 specimens and these were subdivided into 3 groups (unreinforced heat cured acrylic resin as control group),reinforced acrylic resin with( 0.5%wt Nano Al2O3 and2.5%wt plasma treated PP fibers) group and reinforced acrylic with(1%wt Nano Al2O3 and 2.5%wt plasma treated PP fibers group).The tests were impact strength, transverse strength, indentation hardness(shore D), surface roughness thermal conductivity. The results were statistically analyzed using ANOVA test. Results: A highly significant increase in impact strength, surface hardness, thermal conductivity with the addition of 0.5%wt. (Al2O3) and 2.5%wt PP fiber to(PMMA),also there is a significant increase in surface roughness and non significant increase in transverse strength. At the concentration of 1%wt nano (Al2O3) and 2.5%wt PP fiber there is a highly significant increase in impact strength surface hardness and thermal conductivity. Non-significant differences were shown in transverse strength and significant increase in surface roughness. Conclusion: The addition of a composite of Al2O3 nanoparticles and PP fiber to PMMA improves the impact strength, surface hardness and thermal properties, surface roughness while non-significant difference in transverse strength.
The silicon carbide/carbon fiber (SiC/CF) hybrid fillers were introduced to improve the electrical and thermal conductivities of the epoxy resin composites. Results of Fourier transform infrared spectroscopy revealed that the peaks at 3532 and 2850 cm−1 relate to carboxylic acid O–H stretching and aldehyde C–H stretching appearing deeper with an increased volume fraction of SiC. Scanning electron microscopic image shows a better interface bonding between the fiber and the matrix when the volume fraction of SiC particles are increased. As frequency increases from 102 Hz to 106 Hz, dielectric constants decrease slightly. Dissipation factor (tan δ) values keep low a
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A.C electrical conductivity and dielectric properties for poly
(vinyl alcohol) (PVA) /poly (ethylene oxide) (PEO) blends undoped
and doped with multi-walled carbon nanotube (MWCNTs) with
different concentrations (1, and 3 wt %) in the frequency range
(25x103 - 5x106 Hz) were investigated. Samples of (PVA/PEO)
blends undoped and doped with MWCNTs were prepared using
casting technique. The electrical conductivity measurements showed
that σA.C is frequency dependent and obey the relation σA.C =Aωs for
undoped and doped blends with 1% MWCNTs, while it is frequency
independent with increases of MWCNTs content to 3%. The
exponent s showed proceeding increase with the increase of PEO
ratio (≥50%) for undope
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The coupling reaction between tryptamine and 8-hydroxyquinoline led to the formation of a new azo ligand. The synthesized ligand was characterized using CHN, FT-IR, UV-Vis, and NMR spectroscopic techniques. Complexes of the ligand with VO2+, Cr3+, Mn2+, and Mo6+ ions were prepared in a (1:2) ratio, with the general formula [M(L)2]. The obtained complexes were characterized using flame atomic absorption, CHN analysis, FT-IR, and UV-Vis spectroscopy, in addition to magnetic susceptibility and conductivity measurements. The findings suggest that the ligand functions as a bidentate, with the complexes exhibiting octahedral, square planar and square pyramidal geometries. All the complexes were identified as non-electrolytes. Their antioxidant ef
... Show MoreThe study aimed to show the jurisprudential impact of the multiplicity of directing the syntactic movement of the Qur’anic readings, and it was based on the inductive, descriptive and analytical approach. , such as the difference in explaining the ruling on washing the feet, and the one who meditates on the Qur’anic readings notices in it a picture of the Qur’anic miracles, and this is what is manifested by the brevity of the speech. Collapse the research, and the research tried to trace the Qur’anic readings, contained in the verses, and the readings were limited to what is related to the explanatory meaning mentioned by the commentators, by clarifying the explanatory relationship between the Qur’anic readings and the me
... Show Moren this paper, we formulate three mathematical models using spline functions, such as linear, quadratic and cubic functions to approximate the mathematical model for incoming water to some dams. We will implement this model on dams of both rivers; dams on the Tigris are Mosul and Amara while dams on the Euphrates are Hadetha and Al-Hindya.
Fresh vegetables are an important part of a healthy diet. The consumption of raw vegetables without cooking or good washing can be a major rout of transmission to the parasitic infection. The goal of this study was to determine the intestinal parasitic contamination of fresh vegetables from vegetables sales markets in Baghdad province during the different above months of the year. A total of 303 samples of different vegetables were randomly selected from three wholesale markets distributed through different regions in Baghdad (East, West and South) and then were examined by a floatation method. The present study showed that the collected vegetables were contaminated with 12 species of intestinal parasites, and the total percentage of contam
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The research attempts to diagnose the level of the effect of human resources flexibility (employees skills flexibility, employees behaviors flexibility, and human resource practice flexibility) in the south al-rusafa directorate of a power station one of the formations and the Ministry of Electricity, and impact of a range of variables related to the performance operational, namely, (efficiency, effectiveness)recognizing the importance of the subjects studied,& because of the importance of expected results of the field under consideration,researcher selected a sample of size (121) engineers and technicians of workers in the directorate. Was my hypotheses the major search of a relationship and impact between human resources flex
... Show MoreAim: To evaluate the effect of ultrasonic agitation for retrograde biodceramic root repair, MTA and biodentine filling materials on push-out bond strength to dentine walls. Materials and Methods: Ninety extracted human teeth with single straight roots were selected randomly. After disinfection and cleaning, the coronal portions were sectioned to standardize the root canal length at 15mm. following root canal shaping, obturation and apical roots resection, retrograde cavities were prepared. Teeth were categorized depending on the filling material used into three groups, 30 teeth each. Group A filled with bioceramic root repair material, B with MTA and C with Biodentine material. These groups were divided in to three subgroup (n= 10). Subgrou
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This experiment was conducted to evaluate the effect of foliar spraying with gibberellic acid concentrations (0,50,100)mg.L¹ and proline acid concentrations (0, 25, 50)mg.L¹ and their interactions on some growth parameters of pea plant using clay pots in the botanical garden of Biology Department College of Education for pure science Ibn –Al-Haitham ,Baghdad University, for the growing season 2012-2013 the experiment involved the studing of some growth parameters as plant?s height, dry weight, wt. of pods.plant¹, biology yield and the concentration of some major elements (nitrogen, phosphorus and calcium) in plant?s seeds. The experiment was designed according to Completely Randomized Desig(CRD) with three replications. R
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