Background: Polymethyl methacrylate (PMMA) is the most commonly used material in denture fabrication. The material is far from ideal in fulfilling the mechanical requirement. The purpose of this study was to evaluate the effect of addition of 3% wt of treated (silanized) Titanium oxide Nano filler on some physical and mechanical properties of heat cured acrylic denture base material. Materials and methods: 100 specimens were constructed, 50 specimens were prepared from heat cure PMMA without additives (control) and 50 specimens were prepared from heat cure PMMA with the addition of TiO2 Nano fillers. Each group was divided into 5 sub groups according to the test performed which was mixed by probe ultra-sonication machine. Results: A highly significant increase in impact strength and transverse strength was observed with the addition of (TiO2) Nano particles to (PMMA). A significant increase in surface hardness and in surface roughness. The water sorption and solubility were significantly decreased when compared with the control group. Conclusions: The addition of TiO2 Nano particles to heat cure acrylic resin improve the impact strength, transverse strength and surface hardness of heat cure acrylic resin at the same time this addition decrease water sorption and solubility. On the other hand there was an increase in surface roughness with the addition of 3% wt of silanized TiO2 Nano particles. Keywords: NanoTiO2, TMSPM, PMMA.
In this study, the flow and heat transfer characteristics of Al2O3-water nanofluids for a range of the Reynolds number of 3000, 4500, 6000 and 7500 with a range of volume concentration of 1%, 2%, 3% and 4% are studied numerically. The test rig consists of cold liquid loop, hot liquid loop and the test section which is counter flow double pipe heat exchanger with 1m length. The inner tube is made of smooth copper with diameter of 15mm. The outer tube is made of smooth copper with diameter of 50mm. The hot liquid flows through the outer tube and the cold liquid (or nanofluid) flow through the inner tube. The boundary condition of this study is thermally insulated the outer wall with uniform velocity a
... Show MoreNigella sativa seeds (NSS) are reputed traditionally and scientifically as a potent agent that promote milk secretion (galactagogue), but their mechanism of action is studied trivially. One suggestion was that these seeds are bio-transformed to sex hormones within the ovaries. Therefore, this investigation was designated to throw light on the action of these seeds in the absence of ovaries i.e. in male rats. Thirty Norway male albino rats were used in this investigation. They were divided into experimental (n=20,fed NSS 2g/ Kg body weight /day for 14 days) and control (n=10, fed placebo for 14 days). After sacrifice mammary gland and blood samples were obtained. Experimental rats revealed a significant increase (p (0.01>in
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This article reviews the construction of organic solar cell (OSC) and characterized their optical and electrical properties, where indium tin oxide (ITO) used as a transparent electrode, “Poly (3-hexylthiophene- 2,5-diyl) P3HT / Poly (9,9-dioctylfluorene-alt-benzothiadiazole) F8BT” as an active layer and “Poly(3,4-ethylenedioxythiophene)-poly (styrene sulfonate)” PEDOT: PSS which is referred to the hole transport layer. Spin coating technique was used to prepared polymers thin film layers under ambient atmosphere to make OSC. The prepared samples were characterized after annealing process at (80 ͦ C) for (30 min) under non-isolated circumference. The results show a value of filling factor (FF) of (2.888), (0.233) and (0.28
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Abstract
The aim of the current research is to identify the Effect of the alternative evaluation strategy on the achievement of fourth-grade female students in the subject of biology. The researchers adopted the zero hypothesis to prove the research objectives, which is there is no statistically significant difference at the level (0.05) between the average scores of the experimental group who study according to the alternative evaluation strategy and the average scores of the control group who study in accordance with the traditional method. The researchers selected the experimental partial adjustment design of the experimental and control groups with the post-test. The researchers intentionally selected (Al-fed
... Show MoreThis study reports the fabrication of tin oxide (SnO2) thin films using pulsed laser deposition (PLD). The effect of 60Co (300, 900, and 1200 Gy) gamma radiation on the structural, morphological, and optical features is systematically demonstrated using X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), and ultraviolet-visible light analysis (UV-Vis), respectively In XRD tests, the size of the crystallites decreased from 45.5 to 40.8 nm for the control samples and from 1200 Gy to 60Co for the irradiated samples. Using FESEM analysis, the particle diameter revealed a similar trend to that attained using XRD; in particular, the average diameters were 93.8 and
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This study was aimed to explore the impact of social concepts about tribe, clan and women, on internal audit performance. These concepts are considered to be components of the organizational culture and performance of internal audit practice, with respect to the individual and collective performance within the institution. The study, furthermore, was intended to investigate and understand the role of the organizational culture of the tribal, clan and women components with regard to their role in society, in Qatar.
To achieve these objectives, the researcher followed the descriptive analytical approach, using a questionnaire directed to experts and staff working in the banking sector, with the view to test
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The study was conducted to detect the effect of addition of 0.03, 0.06 and0.10% potassium sorbate and 0.10, 0.15, 0.20 and 0.30% sodium propionate upon the sensory properties of laboratory made biscuit. The statistical analysis of the results revealed no significant differences (P<0.05) between the propionate treatment (A,B,C,D) and between the sorbate treatment (E,F,G) and the control (H) in most sensory properties of biscuit prior to storage. Upon six month storage of biscuit made with addition of different levels of sodium propionate 20-40C (room temperature) no significant differences (P<0.05) were shown on softness, flakiness and color in comparison with the control . No significant differences (P<0.05) were also
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