Background: This study aimed to evaluate the effect addition of polyester fibers on the some mechanical properties of heat cured acrylic resin (implant strength, flexural strength and hardness) Materials and methods: Ninety specimens were used in the study. Thirty specimens were used for impact strength measurements (80mm X 10mm X 4mm) length, width and thickness respectively. The specimens divided into three test groups (n=10), first group formed from heat cure acrylic resin without fiber reinforcement. Second group was formed from heat cure acrylic resin was reinforced with 2 mm length polyester fiber and third group was formed from heat cure acrylic resin reinforced with 4mm length polyester fiber, impact strength measured by impact testing device. 30 specimens with (65 mm X 10mm 2.5mm) length, width and thickness respectively were used in 3 groups (n=10) flexural strength test. The flexural strength was measured by using flexural testing device. 30 specimens with (65mm X 10m X 2.5mm) length width and thickness respectively were used for hardness test. The specimens were divided into 3 group (n=10) as in impact strength and flexural strength. Hardness measured by using (shore D hardness tester TH210). Results: revealed statistically significant increase on impact strength especially on 4mm length when compared to control group. Significant decreases in flexural strength of PMMP. When compared to control group with 4mm length fiber reinforcement. Non significant decrease when compared control group with 2mm length fiber reinforced PMMA. Significant decrease in hardness of PMMA resin after reinforcement with 2mm, 4mm lengths polyester fibers. Conclusions: Strengthening with the polyester fiber decreased the flexural strength and hardness of the resin, but increased impact strength. Thus when high impact acrylic resins are needed, fiber reinforced resins may be the material of choice.
Abstract: The increased interest in developing new photonic devices that can support high data rates, high sensitivity and fast processing capabilities for all optical communications, motivates a pre stage pulse compressor research. The pre-stage research was based on cascading single mode fiber and polarization maintaining fiber to get pulse compression with compression factor of 1.105. The demand for obtaining more précised photonic devices; this work experimentally studied the behavior of Polarization maintaining fiber PMF that is sandwiched between two cascaded singe mode fiber SMF and fiber Bragg gratings FBG. Therefore; the introduced interferometer performed hybrid interference of both Mach-Zehnder
... Show MoreDenture bases are fabricated routinely using Poly(methyl methacrylate) (PMMA) acrylic resin. Yet, it is commonly known for its major drawbacks such as insufficient strength and ductility. The purpose of this study was to improve the performance of PMMA acrylic resin as a denture base material by reinforcement with surface treated lithium disilicate glass ceramic powder. The ceramic powder was prepared by grinding and sieving IPS e.max CAD MT blocks. Then, the powder was surface treated with an organosilane coupling agent (TMSPM) and added to PMMA in amount of 1%, 3%, 5% and 7% by weight. Characterizations of the powder was done by particle size analysis, XRD and FTIR. Transverse strength, Impact strength, Shore D hardness and surface roughn
... Show More
(3)
(2)
This work analyzes the impact of MgO nanoparticles on the properties of an epoxy resin solution with uniform structure and particular degree of cure synthesized by the reaction of epoxy resin and pyromellitic dianhydride. Various concentrations of epoxy/MgO nanocomposites were fabricated by mechanical mixing, ultrasonication-based dispersion and casting processes. FTIR results have shown clear differences in the vibrations of C-H, epoxide rings, and main amine N-H groups. This confirms the interaction between MgO particles and the epoxy polymer matrix. X-ray diffraction analysis detected prominent peak at 18.35 degrees, along with additional ones at 43.44 degrees and 62.56 degrees, associated with the (200) and (220) planes of MgO crystal,
... Show More
Density Functional Theory (DFT) with B3LYP hybrid exchange-correlation functional and 3-21G basis set and semi-empirical methods (PM3) were used to calculate the energies (total energy, binding energy (Eb), molecular orbital energy (EHOMO-ELUMO), heat of formation (?Hf)) and vibrational spectra for some Tellurium (IV) compounds containing cycloctadienyl group which can use as ligands with some transition metals or essential metals of periodic table at optimized geometrical structures.
Portland cement is considered the most involved product in environmental pollution. It is responsible for about 10% of global CO2 emissions [1]. Limestone dust is a by-product of limestone plants and it is produced in thousands of tons annually as waste material. To fulfill sustainability requirements, concrete production is recommended to reduce Portland cement usage with the use of alternative or waste materials. The production of sustainable high strength concrete by using nanomaterials is one of the aims of this study. Limestone dust in 12, 16, and 20% by weight of cement replaced cement in this study. The study was divided into two parts: the first was devoted to the investigation of the best percentage of replacement of waste
... Show More
(12)
In this work, the optical properties of Cu2S with different thickness
(1400, 2400, 4400) Ǻ have been prepared by chemical spray pyrolys
is method onto clean glass substrate heated at 283 oC ±2. The effect
of thickness on the optical properties of Cu2S has been studied. It
was found that the optical properties of the electronic transitions on
fundamental absorption edge were direct allowed and the value of the
optical energy gap of Cu2S (Eg) for direct transition decreased from
(2.4-2.1) eV with increasing of the thickness from (1400 - 4400)Ǻ
respectively. Also it was found that the absorption coefficient is
increased with increasing of thicknesses. The optical constants such<
(2)
(4)
The dental amalgam of radioactive materials in the restoration of teeth because of its readily adaptable to existing materials in the oral cavity in addition to mechanical properties such as hardness mechanical resistance Alndgat and others in this study were prepared Almlagm used Guy dental restoration of silver alloy tin plus some elements to improve the characteristicsmechanical such as copper, zinc or indium in addition to mercury
The research aims to investigate the effects of GMAW or MIG welding process on the mechanical properties of dissimilar aluminum alloys 2024-T351 and AA 6061- T651. A series of experimental techniques have been conducted to evaluate mechanical properties of the alloys, by carrying out hardness, tensile and bending tests for welded and un-welded specimens.
Metal inert gas (MIG) has been carried out on sheet metal using ER- 4043(AlSi5) as a filler metal and argon as shielded gas. The welded joints were tested by X-ray radiography and Faulty pieces were excluded.
Welding joints without defects are subjected to heat treatment including heating the joints in furnace to 170 °C for half an hour then air cooling to rel
... Show More