Resilient polymeric materials such as silicone elastomers are currently used for maxillofacial prostheses construction but the strength of these materials and their clinical performance need to be optimized with the addition of reinforcing fillers. This study investigates the effect of zirconia nanopowder addition on tear strength, tensile strength, elongation at break, Shore A hardness, surface roughness and cytotoxicity of VST-50 maxillofacial silicone. Silicone base was mixed with different amounts (1%, 2% and 3%) of zirconia nanopowder using a vacuum mixer. Silicone without filler was used as control for comparison. Scanning Electron Microscopy and Atomic Force Microscopy were utilized to assess the efficiency of high-shear vacuum mixing as filler dispersion method and the surface topography, respectively. Both SEM and AFM images showed that the zirconia nanopowder were distributed fairly well within the polymer. Statistically, highly significant increase in tear strength, tensile strength and hardness with non-significant decrease in elongation at break and non-significant increase in surface roughness were seen with 1% and 2% groups. Whereas with 3% group, there was significant improvement in tear strength, tensile strength and hardness but there was significant undesirable decrease in elongation and increase in roughness. Cytotoxicity test revealed that the addition of zirconia nanopowder was nontoxic to Rat Embryonic Fibroblast (REF) cells and there was non-significant change in the cell viability of all study groups after 24- and 72-hours incubation periods. In conclusion, the addition of 2% by weight nano zirconia to VST-50 maxillofacial silicone could be beneficial in enhancing its performance.
Optical properties and surface morphology of pure and doped Polystyrene films with different divalent metals of Zn, Cu and Sn and one concentration percentage have been studied. Measurements of UV-Vis spectrophotometer and AFM spectroscopy were determined. The absorbance, transmittance and reflectance spectrums were used to study different optical parameters such as absorption coefficient, refractive index, extinction coefficient and energy gap in the wavelengths rang 200-800nm. These parameters have increased in the presence of the metals. The change in the calculated values of energy gaps with doping metals content has been investigated in terms of PS matrix structural modification. The value of opt
... Show MoreIt has become familiar to see alchemy as a methodological approach that combines conscious, diverse, psychological, social, structural, and discrete approaches in the communications technology that Marshall McLuhan found to be able to extend our bodies and senses, The media discourse has a deep and superficial structure produced by the first, with its social, cultural and historical backgrounds, in a context that connects the image with the word, as the "meanings are made" - everywhere, as described by Jonathan ) In fashion, in the arts as a whole, and from its "signs" Our analysis of «meaning», in the media, and communication through advertising, magazines, newspapers, television, and the Internet. Therefore, alchemy is preoccupied wi
... Show More<span lang="EN-US">We are living in the 21<sup>st</sup> century, an era of acquiring necessity in one click. As we, all know that technology is continuously reviving to stay ahead of advancements taking place in this world of making things easier for mankind. Technology has been putting his part in introducing different projects as we have used the field programmable gate arrays (FPGAs) development board of low cost and programmable logic done by the new evolvable cyclone software is optimized for specific energy based on Altera Cyclone II (EP2C5T144) through which we can control the speed of any electronic device or any Motor Control IP product targeted for the fan and pump. Altera Cyclone FPGAs’ is a board thro
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This research included the preparation and characterization of new demulsifies from natural and synthetic polymers of chitosan and polyvinyl alcohol that are environmentally friendly and at the same time have high efficacy comparable to emulsifiers. imported foreign. The prepared compounds were examined using infrared spectroscopy and nuclear magnetic resonance spectroscopy, and all the spectral signals of the polymers were in good agreement with the chemical composition of the polymers. And the melting and decomposition that occur on polymers at high temperatures. The effect of the length and type of side chain in the compositions of polymers on the process of water separation of oil emulsions w
... Show MoreThis research is an attempt to develop exercise with weights to strengthen some of the striking muscles in the shoulder and arm and to develop the accuracy of the smash and rectum skills. The importance of this paper lies in the study of moments of force to achieve the ability to control muscular work and to explore the impact of physical and skill exercises with weights to develop moments of force for some muscles. The experimental method on a sample of players, selected according to the intentional method, including ( 9) advanced players representing Air Force Club participating in the Premier League for season 2011-2012. It is concluded that the exercises proposed have their effective impact on developing the variables of moments force f
... Show MoreA study that collected 240 samples and divided into two groups: the first 120 samples were for diabetics and the second 120 samples were for healthy people, and each group included (90, 20.10) samples from the mouth, urine and vagina respectively, The results showed positive (28.67, 4.00, 1.67) isolates of Candida. In the mouth, urine and vagina, respectively, of diabetic patients compared to (9.33, 2.33, 5.00) positive isolates in the mouth, urine and vagina, respectively, in the healthy. The rate of positive isolates in women was high in women with diabetes and healthy, and it reached 25.33 and 9.00 isolates, respectively, compared with the rate of isolates in men with Candida disease for diabetic patients and healthy people 14.67 and 2.0
... Show MoreIn spite of economic importance of sugar cane and sugar beet as they described as industrial crops they still face decreasing rates of production and productivity in Iraq , and their production was not able to satisfy the local industrial demands for sugar . Thus this study aimed at studying and analyzing, production and productivity of sugar cane and sugar beet in Iraq and this has been done by using non serial data that can be obtained from official offices in Iraq . The area and production of sugar cane in Iraq recorded positive annual growth rates during 1970- 1978 which were 6% and 5% consequently , while the productivity of sugar cane recorded at the same duration of time negative annual growth rate which was 1% , while they recorded
... Show MoreThe new compounds synthesized by sequence reactions starting from a reaction of 4-hydroxybenzaldehyde with 1,5-dibromo pentane to produce dialdehyde)I( .Then compound )I( reacted with different aromatic amines to give schiff bases )IIIV(,thereafter added acetyl chloride to schiff bases to yield N-acyl derivatives)VVII(.While1,3-diazetine derivatives)VIII-X( were synthesized from the reaction of N-acyl derivatives with sodium azide.The reaction of thiourea with N-acyl compounds led to formation of thiourea derivatives (XI-XIII).Finally, the pyrimidine compounds )XIV-XVI( were synthesized by ring closure reaction of compounds(XIXIII) with diethyl malonate.The synthesized compounds were characterized by measurements of melting points,FTIR,1H-N
... Show MoreFour N-substituted citraconisoimides were prepared via dehydration of the corresponding prepared citraconamic acids using N,N\-dicyclohexylcarbodiimide as dehydrating agent. The prepared citraconisoimides were introduced in free radical homopolymerization producing four new poly citraconisoimides. Also the prepared citraconisoimides were introduced in free radical copolymerization with three vinylic monomers including acrylonitrile, methylmethacrylate and methylacrylate producing new copolymers having different physical properties. Moreover two new phenolic resins containing pendent citraconisoimide moiety were prepared via condensation polymerization of N-(hydroxyphenol)citraconisoimide with formaldehyde. The new homopolymers and copoly
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