Polymer composites were prepared using epoxy resin (EP) and unsaturated polyester (UPE) as a blend matrices, which were mixed together in different percentages (starting from 90:10) of (epoxy/polyester) respectively, and ending with (50:50) of (epoxy/polyester). The optimum mixing ratio (OMR) of the components was decided upon the results of the impact strength value of these blending ratio, which showed the highest value of (16.3) KJ/m2 for the blending ratio (80:20) of (EP/UPE) respectively.
The blend with (OMR) was chosen to be reinforced with three different weight fractions of reinforcement; the 1st one was reinforced with nano titanium oxide (TiO2) with a weight fraction (2% wt.), the 2nd one was reinforced with both nano (TiO2) and surface modified nano silica particles (SiO2) with weight fractions (2% & 0.5%) respectively, and the 3rd one was reinforced with nano (TiO2) and surface modified (SiO2) with weight fractions (2% & 1%) respectively. The tested mechanical properties were (flexural strength, impact strength, hardness, and water uptake).
Hand lay-up technique was used to prepare the samples, and a magnetic stirrer was used to ensure maximum homogeneity of the nano particles in the blend. All fabricated samples were exposed to water for 10 weeks to investigate the effect of nano powders addition on diffusivity and maximum water uptake, obvious degradation in mechanical properties of the composite consisting of (blend matrix/TiO2 reinforcement) and (blend matrix/TiO2+SiO2 reinforcement) were observed as a result of liquid uptake with less severe impact, but more effect on flexural strength and shore D hardness. Fick’s 2nd law was used to explain diffusion mechanism. All the results were discussed.
Background: Radiotherapy, is therapy using ionizing radiation in order to deliver an optimal dose of either particulate or electromagnetic radiation to a particular area of the body with minimal damage to normal tissues. The source of radiation may be outside the body of the patient (external beam irradiation) or it may be an isotope that has been implanted or instilled into abnormal tissue or a body cavity. Called also radiotherapy. The aim of work studies the relationship between the depth dose and the high photon xray energies (6MeV and 10MeV). Patients and methods: in our work, we studied the dose distribution in water phantom given at different depths (zero-18) cm deep at1cm intervals treated with different field size (5×5-,10×1
... Show MoreA Laced Reinforced Concrete (LRC) structural element comprises continuously inclined shear reinforcement in the form of lacing that connects the longitudinal reinforcements on both faces of the structural element. This study conducted a theoretical investigation of LRC deep beams to predict their behavior after exposure to fire and high temperatures. Four simply supported reinforced concrete beams of 1500 mm, 200 mm, and 240 mm length, width, and depth, respectively, were considered. The specimens were identical in terms of compressive strength ( 40 MPa) and steel reinforcement details. The same laced steel reinforcement ratio of 0.0035 was used. Three specimens were burned at variable durations and steady-state temperatures (one
... Show MoreThe current study aimed the syntheses and characterizations of Gold nanoparticles (Au NPs) using a laser ablation Q-switched Nd: YAG laser with a wave-length of 355 nm at a variety of laser pulse energies (E) and deposited on porous silicon (PS). Optical emission spectrometer was used to diagnosed medium air to study gold plasma characteristics and prepared Au nanoparticles. The laser pulse energy influence has been studied on the plasma characteristics in air. The data showed the emergence of the ionic (Au II) spectral emission lines in the gold plasma emission spectrum. XRD has been utilized to examine structural characteristics. Moreover, AFM results 37.2 nm as the mean value of the diameter that is coordinated in a shape similar to the
... Show Morea laser ablation Q-switched Nd: YAG laser with a wave-length of 355 nm at a variety of laser pulse energies (E) and deposited on porous silicon (PS). Optical emission spectrometer was used to diagnosed medium air to study gold plasma characteristics and prepared Au nanoparticles. The laser pulse energy influence has been studied on the plasma characteristics in air. The data showed the emergence of the ionic (Au II) spectral emission lines in the gold plasma emission spectrum. XRD has been utilized to examine structural characteristics. Moreover, AFM results 37.2 nm as the mean value of the diameter that is coordinated in a shape similar to the rod that appears for Au NPs, in addition to that, TEM has been an indication of the fact that syn
... Show MoreThis paper focused on the stone matrix asphalt (SMA) technology that was developed essentially to guard against rutting distress. For this procedure, fibers play a racy role in stabilizing and preventing the drain down problem caused by the necessity of high binder content coupled with their strengthening effect. A set of specimens with cylindrical and slab shapes were fabricated by inclusions jute, polyester, and carbon fibers. For each type, three contents of 0.25%, 0.5%, and 0.75% by weight of mixture were added by lengths of 5, 7.5, and 10 mm. The prepared mixtures were tested to gain the essential pertained parameters discriminated by the values of drain down, Marshall quotient, rut depth, and dynamic stability. It
... Show MoreIn this work, three inorganic additives were 1,1sed, these are (I) ;
tetraethyl ammonium bromodichloro phenylphsphin, (II) Chlorinated paraffine. and (ITI) a mixture of (50% by weight of each) to study the synergetic effect. These additives \'v·cre used as flame retardants with unsaturated polyester and epoxy resins.;, since these resins are industrially important and of \Vide uses in life.
Results showed efficiency of these additives to retard fl mmabillty and stop burning of resins throqght the ASTM tests used Measurement of Limiting oxygen index (LOI), &nbs
... Show MoreBackground: This study was done to assist X-ray diffraction and biocompatability of glass ionomer cement reinforced by different ratios of Hydroxyapatite. Materials and Methods: The powder of glass ionomer cement reinforced by different ratios of Hydroxyapatite were used to get X-ray diffraction pattern by X-ray diffraction machine, While for biocompatibility test, A polyethylene tubes containing glass ionomer cement reinforced by different ratios of Hydroxyapatite were implanted on the dorsal submucosal site of Rabbit's tissues and histological slide were prepared for histopathological study. Results: X-ray diffraction test showed that all elements of glass ionomer cement reinforced by different ratios of Hydroxyapatite were react with eac
... Show MoreBackground: The demand for better esthetic during orthodontic treatment has increased nowadays, so orthodontists starting using esthetic arch wires, brackets and ligatures.Tooth colored brackets were introduced in different types of materials. Sapphire ceramic brackets are one type of esthetic brackets and their color stability remains the main concern for the clinicians and patients at the same time. The present study design to evaluate the effect of three different staining materials (pepsi, black tea and cigarette smoke) on the stainability of sapphire ceramic brackets bonded with three types of light cure orthodontic adhesives which include: Resilience, Enlight and Transbond. Materials and Methods: The sample consisted of three hundre
... Show MoreA field experiment was carried out during the 2020 season at the College of Agricultural Engineering/ University of Baghdad, Al-Jadriya to evaluate the effect of dry farming when applying water stress under the subsurface drip irrigation system on water productivity and rice yield. The experiment was conducted with three levels of irrigation water stress when 10, 20 and 40% of the available water was depleted and in three dimensions between drip lines 10, 15 and 20 cm. The experiment was designed according to a randomized complete block design, according to the split plot design, with three replications. Determine the depth of irrigation water depending on the moisture depletion of th