Background: Deterioration of maxillofacial silicone properties due to microbial colonization is a common problem and leads to the replacement of the prosthesis. Incorporation of the antimicrobial agent into the silicone could be a solution. The purpose of this study was to evaluate the effect of silver-zinc zeolite addition on some mechanical properties of a maxillofacial silicone (VST-50). Materials and methods: Total 120 specimens were fabricated and divided into 3 groups: 40 specimens for tear strength test, 40 specimens for tensile and percentage of elongation tests and 40 specimens for Shore A hardness and surface roughness. Each group was divided into 4 subgroups according to the amount of zeolite added (0% “control”, 0.5%, 1% and 1.5%). One-way ANOVA and Tukey’s HSD tests were used to analyze the study data. FTIR revealed a chemical interaction between zeolite and silicone. Results: Study results revealed a highly significant increase in tear strength (p<0.01) in all experimental subgroups. The tensile strength of 1% filler was significantly higher than the control group (p<0.01) while 0.5% and 1.5% showed a non-significant increase. All experimental groups demonstrated a highly significant decrease in the percentage of elongation and a highly significant increase in roughness (p<0.01). The subgroup with 1.5% zeolite showed a highly significant increase in hardness, other subgroups showed a non-significant increase. Conclusion: The addition of 1% Ag-Zn zeolite improved some mechanical properties of VST-50 maxillofacial silicone.
Background: Levetiracetam is a member of the new antiepileptic drugs and has a broad spectrum effect, used as an adjunctive therapy in addition to monotherapy in the treatment of partial onset-seizures. The effect of levetiracetam on the development of embryo nervous system after maternal exposure during pregnancy has not been identified. Objective: to evaluate the effect of antiepileptic drug, levetiracetam (LEV) within its therapeutic dose 350mg/Kg body weight on albino female rat to clarify its effect on the developing cerebral cortex histologically. Material And Methods: Ten pregnant female rats were separated into two groups, control group and experimental group. They were obtained from the animal house of the high institute of inferti
... Show MoreIn this paper the effect of mixing TiO2 nanoparticles with epoxy resin is studied. The TiO2 nanoparticles would be synthesis and characterized by scanning electron microscopy (SEM), XRD FTIR, for two particle sizes of 50 and 25 nm. The thermal conductivity is measured with and without composite epoxy resin; the results showed that the thermal conductivity was increased as nanoparticle concentration increased too. The thermal conductivity was increased as particle size decreased.
In this study, the zinc oxide NPs have been synthesized from the fresh pomegranate peels extract using the precipitation method. The ZnO nanoparticles were produced from the reaction of fresh peels extract with zinc acetate salt which was used as zinc source in the presence of 2 M NaOH. The green synthesized nanoparticles were characterized through X-ray diffraction (XRD), UV-Vis diffuse reflection spectroscopy, Fourier transform infrared spectroscopy (FTIR), and Atomic force microscopy (AFM). The XRD patterns confirm the formation of hexagonal wurtzite phase structure for ZnO synthesized using pomegranate peels extract with average crystalline size of 28 nm. FTIR spectra identify the presence of many active functional groups for the pom
... Show MoreIn this research, the mechanism of cracks propagation for epoxy/ chopped carbon fibers composites have been investigated .Carbon fibers (5%, 10%, 15%, and 20%) by weight were used to reinforce epoxy resin. Bending test was carried out to evaluate the flexural strength in order to explain the mechanism of cracks propagation. It was found that, the flexural strength will increase with increasing the percentage weight for carbon fibers. At low stresses, the cracks will state at the lower surface for the specimen. Increasing the stresses will accelerate the speed of cracks until fracture accorded .The path of cracks is changed according to the distributions of carbon fibers
In this work, some mechanical properties of the polymer coating were improved by preparing a hybrid system containing Graphene (GR) of different weight percentages (0.25, 0.5, 1, and 2wt%) with 5wt% carbon fibres (CF) and added to a polymer coating by using casting method. The properties were improved as GR was added with further improvement on adding 5wt% of CF. The impact strength of acrylic polymer with GR increases with increasing weight ratio of GR; maximum value was obtained when the polymer coating was incorporated with 1wt% GR and 5wt% CF. The impact strength of acrylic polymer with GR and GR/CF composites incorporated with GR at 1wt% and CF at 5wt%. Hardness increase with increasing weight ratio of Gr and a significant imp
... Show MoreIn this project we analyze data of a large sample of gas rich dwarfs galaxies including; Low Surface Brightness Galaxies (LSBGs), Blue Compact Galaxies (BCGs), and dwarfs Irregulars (dIr). We then study the difference between properties of these galaxies in the range of radio frequencies (B-band). The data are available in HIPASS catalogue and McGaugh’s Data Page. We depended also NASA/IPACExtragalactic Databes web site http://ned.ipac.caltech.edu in the data reduction. We measured the gas evolution (HI mass), gas mass-to-luminosity ratio, and abundance of the elements such as the oxygen abundance for these galaxies. Our results show a
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