Materials Science Forum Vol. 1021

Abstract: The aims of this study are to improve thermal characteristics and decrease electrical consumption of air-conditioning as well as, to increase the performance (COP) of cooling cycle. CuO nanoparticles (0.003 mass fraction) have been added to compressor oil of air conditioning (1 ton capacity, split-unit) used Freon gas (R22), and then compared with pure oil compressor of air conditioning under same environmental conditions. The results showed that the increasing of density ratio, COP and viscosity ratio are 3%, 50% and 1.8% respectively while the decreasing of electrical consumption is 51.2%. The experimental data are compared with previous data in the literature to be validated. It can be recommended that the nano-oil is significant utilizing in air conditioner compressors for energy consumption applications.

Abstract: Cobalt oxide thin film (Co₃O₄) has been prepared from cobalt chloride with distilled water on conducting glass substrates Fluorine doped Tin Oxide (FTO) at (400^ºC) by depositing chemical spray pyrolysis, with thickness (200 nm). The structural properties are studied by XRD. Also, optical properties and electrical properties of Co₃O₄ thin film are studied by UV spectroscopy and Cyclic voltammetry (CV) respectively. The effects of gamma irradiation on optical properties are also examined. XRD results showed that the film was polycrystalline with cubic structure having preferred orientation (111). The as-prepared Co₃O₄ film exhibits a noticeable EC behaviour with reversible colour which changes from dark grey to pale yellow with bleaching time (55 s) and colouring time (40 s). After irradiation, the optical properties showed that as the transmittance decrease leads to decrease the direct optical band gap from (3.68eV) to (3.55eV)

Abstract: This research introduced Intelligent Network's proposed design for predicting efficiency in the removal of phenol from wastewater by liquid membrane emulsion. In the inner phase of W / O emulsions, phenol extraction from an aqueous solution was investigated using emulsion liquid membrane prepared with kerosene as a membrane phase, Span 80 as a surfactant, and NaOH as a stripping agent. Experiments were conducted to investigate the effect of three emulsion composition variables, namely: surfactant concentration, membrane phase to-internal (V_M / V_I) volume ratio, and removal phase concentration in the internal phase, and two process parameters, feed phase agitation speed at organic acid extraction rates, and emulsion-to-feed volume ratio (V_E / V_F). More than 98% of phenol can be extracted in less than 5 minutes. This article describes compares the performance of different learning algorithms such as GD, RB, GDM, GDX, CG, and LM to predict the efficiency of phenol removal from wastewater through the liquid emulsion membrane. The proposed neural network consisted of (7, 11, 1) neurons in the input , hidden and output layers respectively feed forward ANN with various types of back propagation training algorithms were developed to model the emulsion liquid membrane removal of phenols. The values predicted for the neural network model are found in close agreement with the results of the batch experiment using MATLAB program with a correlation coefficient ( R²) of 0.999 and Mean Squared Error (MSE) of 0.004.

Abstract: In this work, high crystalline CdS thin films were formed by using thermal evaporation technique (TET) under vacuum proses 10^-6 Torr using vacuum system (Edwards Co.) . The results were investigated the structure, morphology and crystal size of films using XRD and FESEM. The antibacterial activity of CdS thin films was performed by measuring the zone of inhibition using diffusion plate method against a test organism like E.coli and S.aureus and evaluated the activity of CdS thin films in removal bacteria. The preparation method of CdS using thermal evaporation technique (TET) expands the horizon to biological systems as an essential medicinal agent.

Abstract: This paper presents a nonlinear finite element analysis of RC beam-column joints. A numerical study carried out through a simulation on beam-column joints failed in flexure presented by experimental study. A verification procedure was performed on two joints by finite element analysis with ANSYS APDL. The verification with the experimental work revealed a good agreement through the load-displacement relationship, ultimate load, and displacement, and crack pattern. Also, the parametric study was implemented which including strengthening the concrete members by a variable ratio of steel fibers with normal ratios (0.5%, 1%, 1.5%, and 2%) and ratios of slurry infiltrated fiber concrete SIFCON (steel fibers up to 4%, 6%, and 8%) in addition to using of partial and full strengthening with and without stirrups. The test results revealed that steel fibers enhanced the flexural strength and ductility of the tested joint. Increase the ratio of steel fibers increased the flexural capacity by (101%, 153%, 177%, and 193%) for the four normal ratios of steel fibers respectively. SIFCON concrete ratios (4%, 6%m and 8%) enhanced ultimate strength by (521%, 802%, and 906%) respectively. The use of steel fibers reinforcement instead of steel rebar enhanced the ultimate load capacity by (101%) with large displacement. Full strengthening method by use of SIFCON presented pure flexural failure with cracks spread in the joint region but use the SIFCON concrete as a partial strengthening changed the failure mode to the shear failure.

Abstract: This study aimed to show the enhanced effect of nanoparticles cobalt ferrite CoFe₂O₄ with chlorhexidine on Enterococcus faecium isolated from failure root canal treatment cases. Sol-gel technique was used to prepare the spinel cobalt ferrite CoFe₂O₄ at 200 °C then sintering at 400 °C & 600 °C, whereas the antimicrobial susceptibility test of nanoparticles was carried out according to the Kirby-Bauer technique compared with chlorhexidine. Fifteen isolates of Enterococcus faecium obtained by inserting sterile paper points in root canals, from patients who consulted the Teaching Hospital of Dentistry College at the University of Mosul, Iraq. For the first time, results showed that the nanoparticle cobalt ferrite CoFe₂O₄ at 400 °C and 600 °C, when mixed with chlorhexidine, give the mean inhibition zone 8.5334 mm and 8.0667mm respectively, while the pure chlorhexidine was providing a mean inhibition zone of 3.1667 mm, and also the nanoparticles cobalt ferrite in both cases of sintering without mixing, there was no antimicrobial effect. Statistical analysis using Duncan showed significant differences among groups (p < 0.05).

Abstract: The effect of adding nanomaterial of aluminum oxide (Al2O3), titanium oxide (TiO2) and zirconium oxide (ZrO2) in different concentrations of 0.25, 0.5, 0.75, 1.0, and 1.25 g/L to the cold fluid (water) turbulently flowing with different flow rates of 75, 100, 125, 150, and 175 L/min in tube side countercurrently to hot water flowing with a constant flow rate of 60 L/min in the shell side of shell and tube heat exchanger on the heat transfer rates and overall heat transfer coefficients are experimentally studied. It is found that the addition of nanomaterials gives rise to outlet cold (nano) fluids temperatures causing to enhancement averagely 7.74, 11.25, and 17.38 percent for ZrO2, TiO2, and Al2O3 respectively in heat transfer rate and averagely 12.72, 19.47, and 28.71 percent for ZrO2, TiO2, and Al2O3 respectively in overall heat transfer coefficients. The maximum enhancement values in heat transfer rates and in overall heat transfer coefficients are attained at a flow rate of 150 L/min of cold fluid.

Abstract: We prepared Zinc oxide nanomaterial employing PLA (pulsed laser ablation) technique. A pure Zn target was immersed in ultra-pure water (UPW) and it was subjected to several pulses (1st. and 2nd. harmonic) of the pumping Nd: YAG laser. The influence of changing laser’s wavelength (1064, 532) nm on the characterization of the produced nanoparticles was studied. The results obtained from studying the structure, topography, and morphology of the product showed that the particles have a hexagonal shape. Also, changing the wavelength of the laser from 532nm to 1064nm leads to size reduction and density increasing of the nanoparticles.

Abstract: Transfer the load from the foundation to the soil causes deformation that soil and surface of the soil near the foundation. Results of the settlement or deformation occurring under the foundation cause destroyed of structure built on it, due to the soil fail. This paper presents a numerical analysis to study the settlement of unusual footing (L-shape) on a two-layered soil using finite element program (ELPLA). Two cases for layered soil were studied, the first case of a layer of sand over the clayey soil, and the second case of clayey soil over the sand soil. The footing (L shape) having different depth from the surface of soil (0, 0.5, 1.0, 1.5, 2.0 and 2.5m) and the loading was (0, 50, 100, 150, 200 and 250 kN/m2) for two cases of layered soil are analyzed. The results for this analysis show that the settlement increase with depth of footing for each load, and when the loading increase the settlement also increase. Curves for load – settlement were almost similar for all depths of footing. Settlements values various between two cases , when sandy soil over clayey soil the settlements was high than when clayey soil over sandy soil.

Abstract: Almost all hospitals use radioisotopes for different purposes, as their applications grow, so their concentration in the waste of those hospitals does. To address this issue, twenty-nine samples were collected from (9) sites, these samples were collected from the incinerators of medical areas and the waste collection chambers. After collecting the samples, they were prepared for the examination, where a high-purity Germanium detector (HPGe) was used to detect radioactive elements. The lead element (Pb-214) of the uranium chain (U-238) and the actinium element (Ac-228), the lead element (Pb-212) of the thorium chain (Th-246) and the potassium element (K-40) appeared in some medical areas Iodine (I-131). Some regions showed high concentrations of these elements compared to some sites, Iodine (I-131) appeared in high rates in some hospitals specialized in treating cancerous diseases. The equivalent efficacy of radium, the annual equivalent internal and external dose, and the internal and external risk factors were calculated and the results obtained were compared with the global limits.