In 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 machines, the ESD increases with age. The lowest recorded radiation dose was from hospital 1 machine 2. In this facility ESD ranged from 19.93 µGy to 67.66 µGy for chest X-ray, from 39.03 µGy to 82.63 µGy for abdomen (AP), and from 35.47 µGy to 94.27 µGy for skull (AP). In contrast the highest dose levels are recorded from hospital 2 machine 1; the minimum ESD for chest X-ray is 247.51 µGy and the maximum is 2393.12 µGy; for abdomen X-ray the lowest ESD is 269.05 µGy and the highest value is 5106.15 µGy; and for skull X-ray minimum values is 430.96 µGy and the maximum value is 3072.77 µGy. In conclusion, for the considered pediatrics examinations, most of ESD values are within the international acceptable level and some are higher >100% .
Flat-plate collector considers most common types of collectors, for ease of manufacturing and low price compared with other collectors. The main aim of the present work is to increase the efficiency of the collector, which can be achieved by improving the heat transfer and minimize heat loss experimentally. Five types of solar air collectors have been tested, which conventional channel with a smooth absorber plate (model I), dual channel with a smooth absorber plate (model II), dual channel with perforating “V” corrugated absorber plate (model III), dual channel with internal attached wire mesh (model Ⅳ), and dual channel with absorber sheet of transparent honeycomb, (model Ⅴ). The dual channel collector used for
... Show MoreIn this research, rabbit femurs were implanted with CP Ti screws coated with a combination of CaCO3 and nanohydroxyapatite, and the effect on osseointegration was assessed using histological and histomorphometric examination at 2 and 6 weeks. CaCO3 and nanohydroxyapatite were combined with the EPD to coat the surfaces of the CP Ti screws. The femurs of five male rabbits were implanted with coated and uncoated implant screws. Healing time was divided into two groups (2 and 6 weeks). After 2 and 6 weeks of implantation, the histological examination revealed an increase in the growth of bone cells for coated screws, and the histomorphometric analysis revealed an increase in the percentage of ne
... Show MoreThis study introduces a highly sensitive trapezium-shaped PCF based on an SPR refractometric sensor with unique design features. The structure of a sensor was designed and analyzed using COMSOL Multiphysics v5.6 based on Finite Element Method (FEM) with a focus on investigating the influence of various geometric parameters on its performance. The two channels were coated with a metallic gold layer to provide chemical stability, and a thin layer of TiO₂ improved the gold's adhesion to the fiber. The findings indicate that the proposed sensor achieves maximum amplitude and wavelength sensitivities of 1,779 RIU⁻¹ and 30,500 nm/RIU, respectively, with corresponding resolutions of 3.2
In this research, an organobentonite (HDTMA-BT) was prepared by modifying a jordanian bentonite (BT) with hexadecyltrimethylammonium bromide. By means of in situ free radical polymerization in THF with AIBN as the initiator, this organobentonite is used to prepare the polymethylmethacrylate-bentonite (PMA-HDTMA-BT) nanocomposite. Scanning electron microscopy (SEM), x-ray diffraction (XRD), energy dispersive spectrometer (EDS) and Fourier transform infrared (FTIR) spectroscopy were used to characterize both HDTMA-BT and PMA-HDTMA-BT. Those adsorbents were used in a batch process to remove Pb(II), Cr(III) ions, and p-chlorophenol (PCP) from aqueous solution. Investigated factors included adsorbent dosage, initial pH solution, contact time, an
... Show MoreExperimental work was carried out to investigate the effect of fire flame (high temperature) on specimens of one way slabs using Self Compacted Concrete (SCC). By using furnace manufactured for this purpose, twenty one reinforced concrete slab specimens were exposed to direct fire flame. All of specimens have the same dimensions. The slab specimens were cooled in two types, gradually by left them in the air and suddenly by using water. After that the specimens were tested under two point loads, to study, the effect of
different: temperature levels (300ºC, 500ºC and 700ºC), and cooling rate (gradually and sudden cooling conditions) on the concrete compressive strength, modulus of rupture, flexural strength and the behavior of reinf
The growing demand for sustainable and high-performance asphalt binders has prompted the exploration of waste-derived modifiers. This study investigates the performance enhancement of Natural Asphalt (NA) using Sugarcane Molasses (SM) and Waste Engine Oil (WEO). The modified blends were prepared by partially replacing 50 % NA with varying proportions of SM and WEO ranging from 10 % to 40 % of the total weight of NA. Comprehensive testing was conducted, including penetration, softening point, ductility, viscosity, Bending Beam Rheometer (BBR), Multiple Stress Creep Recovery (MSCR), Energy Dispersive X-ray Spectroscopy (EDX), Fourier Transform Infrared (FTIR) spectroscopy, and Scanning Electron Microscopy (SEM). The results demonstrated that
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