Gypsum Plaster is an important building materials, and because of the availabilty of its raw materials. In this research the effect of various additives on the properties of plaster was studied , like Polyvinyl Acetate, Furfural, Fumed Silica at different rate of addition and two types of fibers, Carbon Fiber and Polypropylene Fiber to the plaster at a different volumetric rate. It was found that after analysis of the results the use of Furfural as an additive to plaster by 2.5% is the optimum ratio of addition to that it improved the flexural Strength by 3.18%.
When using Polyvinyl Acetate it was found that the ratio of the additive 2% is the optimum ratio of addition to the plaster, because it improved the value of the flexural strength by a rate of 3.44% of the value of standards fraction of the mixture of reference. It was noted that the optimum ratio for the addition of Fumed Silica to the plaster is the ratio of 1%, because this ratio of addition increases the flexural strength by 15.26%. For the addition of Carbon Fiber to the plaster it was found that the volumetric ratio of the additive 0.5% is the percentage of perfect accessory after taking into account cost and quality which gives an increase in Flexural Strength by rate of 41.43% .When using Polypropylene Fiber it was found that the optimum percentage ratio of addition 1.5%, where this ratio increases flexural strength by a rate of 23.67% . When using the mixture (PVCF), which contains 2% of Poly vinyl Acetate and 0.5% as a volumetric rate of the carbon fiber to the plaster, increases the value of Flexural Strength by a rate 62.92%. After analyzing the results for all mixtures it was found that the mixture (PVCF) is the best one to satisfy the aim of the research which is to get the best structural properties specially flexural strength for gypsum beams.
Background: Odontogenic tumors are a diverse group of lesions with a variety of clinical behavior and histopathologic subtypes, from hamartomatous and benign to malignant. The study aimed to examine the clinical and pathological features of odontogenic tumors in Baghdad over the last 11 years (2011–2021). Materials and Methods: The present retrospective study analyzed all formalin-fixed, paraffin-embedded tissue blocks of patients diagnosed with an odontogenic tumor that were retrieved from archives at a teaching hospital/College of Dentistry in Baghdad University, Iraq, between 2011 and 2021. The diagnosis of each case was confirmed by examining the hematoxylin and eosin stained sections by two expert pathologists. Data from pati
... Show MoreThe antibacterial activity of Capparis spinosa L. extracts obtained from Baghdad was evaluated against six clinical bacteria isolates of Helicobacter pylori. The results presented in this work demonstrated that the leaves extract showed a significant effect against bacteria as compared to the root and fruit extracts at 100 mg/ml concentration, with inhibition zone ranging from 12.0 to 30.7 mm in each bacteria strain. The end results of GC-MS analysis indicated that the ethanol extracts of caper have a lot of active chemical compounds, including twenty-five, eighty-two and sixty-eight phytoconstituent compounds, that are distinguished in the extracts of roots, leaves and fruits with C. spinosa L. respectively. I
... Show MoreIn this work, mesoporous silica SBA-15 was prepared and functionalized with amine groups (i.e., NH2) to form NH2/SBA-15. The curcumin (CUR) was encapsulated into the surface and pore of NH2/SBA-15 to create CUR@NH2/SBA-15 as an efficient carrier in drug delivery systems (DDSs). The three samples (i.e., SBA-15, NH2/SBA-15, and CUR@NH2/SBA-15) were characterized. The study investigated the effect of the carrier dose, initial CUR concentration, pH, and contact time on the CUR loading efficiency (DLE%) via adsorption. The best DLE% for the SBA-15 and NH2/SBA-15 were found to be 45% and 89.7%, respectively. The Langmuir isotherm had a greater correlation coefficient (R2) of 0.998 for SBA-15. A pseudo-secondorder kinetic model seemed to fit well
... Show MoreIn the geotechnical and terramechanical engineering applications, precise understandings are yet to be established on the off-road structures interacting with complex soil profiles. Several theoretical and experimental approaches have been used to measure the ultimate bearing capacity of the layered soil, but with a significant level of differences depending on the failure mechanisms assumed. Furthermore, local displacement fields in layered soils are not yet studied well. Here, the bearing capacity of a dense sand layer overlying loose sand beneath a rigid beam is studied under the plain-strain condition. The study employs using digital particle image velocimetry (DPIV) and finite element method (FEM) simulations. In the FEM, an experiment
... Show MoreThe solidification process in a multi-tube latent heat energy system is affected by the natural convection and the arrangement of heat exchanger tubes, which changes the buoyancy effect as well. In the current work, the effect of the arrangement of the tubes in a multi-tube heat exchanger was examined during the solidification process with the focus on the natural convection effects inside the phase change material (PCM). The behavior of the system was numerically analyzed using liquid fraction and energy released, as well as temperature, velocity and streamline profiles for different studied cases. The arrangement of the tubes, considering seven pipes in the symmetrical condition, are assumed at different positions in the system, i
... Show MoreIn this study the Entrance Surface Dose (ESD) received by pediatrics patients undergoing chest, abdomen and skull X-ray examinations was estimated. The study was conducted in two hospitals in Najaf city where three radiographic systems were considered. The study participants were classified into four age groups 0-1 , 1-5 , 5-10 and 10-15 years. Calculations were performed using exposure factors, kVp, mAs and focal-skin distance, together with patient data age. The ESD was calculated for the involved patients who underwent an Antero-posterior (AP) chest, abdomen and skull X-ray examination. The resulted data were analyzed and compared with international dose references. For all studied radiographic examinations and all X-ray mac
... Show MoreNew nitrone and selenonitrone compounds were synthesized. The condensation method between N-(2-hydroxyethyl) hydroxylamine and substituted carbonyl compounds such as [benzil, 4, 4́-dichlorobenzil and 2,2́ -dinitrobenzil] afforded a variety of new nitrone compounds while the condensation between N-benzylhydroxylamine and substituted selenocarbonyl compounds such as [di(4-fluorobenzoyl) diselenide and (4-chlorobenzoyl selenonitrile] obtained selenonitrone compounds. The condensation of N-4-chlorophenylhydroxylamine with dibenzoyl diselenide obtained another type of selenonitrone compounds. The structures of the synthesized compounds were assigned based on spectroscopic data (FT-IR,
... Show MoreFor the treatment of pathogenic bacterial infections, multidrug resistance (MDR) has become a major issue. The use of nanoparticles is a promising strategy for combating medication resistance in a variety of pathogens that cause deadly diseases. The goal of our research was to extract multidrug-resistant bacteria from wound infections and then use iron oxide nanoparticles (Fe3O4) as alternative therapeutic agents in vitro. Gram staining, morphological attributes evaluation, and biochemical testing were used to assess the microbes. The Kirby-Bauer disk diffusion method was used to test MDR-bacterial strains against several antibiotics; the majority of these isolates were resistant to ceftazidime, amoxicillin
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