Al-Qadisiyah Journal for Engineering Sciences

The model fuel (Heptane contained 2500 ppm from DBT) was desulfurized electrochemically at a constant current (300 mA), in which the process consists of two steps; the first step is electrochemical desulfurization by using an electrochemical cell containing two graphite electrodes immersed in the electrochemical cell; the cell contains model fuel, hydrogen peroxide as oxidation agent, 0.106 M is NaCl to enhance electrolyte electrical conductivity. The investigation was at different operation parameters; temperature range (40-50-60 °C), stirring time (10-20-30-40-50) min, while the second step is extraction with acetonitrile. The results show final sulfur concentration decreased when increasing time at the same temperature for example. Kinetics parameters calculation shows that electrochemical desulfurization ECD reaction follows pseudo 1st order reaction, the rates constant of reaction are 0.0175, 0.0191, and, 0.0193 at temperatures 40, 50, and 60 °C, respectively, while activation energy equal 4.433 kJ/mol.

This paper investigates numerically the combined effects of a construction joint and reduction in the cross-section area of negative reinforcement in a one-way continuous slab on the structural behavior and the efficiency of three types of strengthening techniques. In this paper, the models made by ABAQUS (software) are used to numerically represent the specimens and simulate the applied loading. This numerical study\'s models represent six one-way continuous slabs, as a part of an experimental study. The specimen\'s dimensions were (2200 mm in length, 500 mm in width, and 100 mm in thickness). Five of the six models had a vertical construction joint and reduced the negative reinforcement steel bars\' cross-sectional area. The sixth specimen is used as a reference. The proposed strengthening technique was Carbon fiber Reinforced Polymers strips, 6 mm Carbon fiber Reinforced Polymers bars Near the Surface Mountain technique, and steel plates. All the proposed strengthening\'s applied to the tension side on the top face at the internal support. The program outcomes are represented visually as stress distribution diagrams, load-deflection curves, and crack patterns. The results from the numerical analysis compared to the experiment results. In the experiment, the reduction in the cross-section area resulting from partial corrosion happened in one span due to the outdoor atmosphere\'s exposure because of the stoppage in the concrete pouring, which also resulted in forming the construction joint. The results highlighted the construction joint\'s effect and the steel cross-sectional area reduction on the ultimate load and the deflection. The proposed strengthening methods improved the member\'s overall responses, and There was a good convergence between the numerical and experimental works that verify the specimens\' observed behavior.

The current review covers numerical analysis using the MATLAB program for multi-layer composite materials. Which involves studies related to the intersection with fibers, between layers and piezoelectric layers or patches. It has been reported that using MATLAB program has great flexibility in analysis due to its library which includes various numerical methods. In addition to programming and developing the finite element technology to calculate the stress and strain in each layer based on different deformation methods such as (FSDT and HSDT), to obtain mechanical properties. It has been claimed that there is a deviation in results between MATLAB and Ansys for the same 20-layer composite material. Using MATLAB in dynamic analysis in various methods such as Newmark, Rayleigh damping, Timoshenko, and Euler-Bernoulli exhibit good agreement with natural frequencies and mode shapes. Moreover, MATLAB is useful for the real-time process of data acquisition to deliver a digital model of a composite material coated with a piezoelectric plate and is an ideal material for sensing, detecting, and controlling vibration inhibition.

In recent times the EAHE is widely used as a passive cooling and heating technique due to the mounting thermal potential of the earth and because of the energy crisis. In the past years much, research has been published including studying this type of heat exchanger and using it in many applications and many locations with different climate conditions. Also, this research investigated the most affecting parameters. In this paper, a review is prepared to survey the published literature in this field to shed light on the research.

The present work describes a coating process that was carried out on the surface of graphene oxide powder. Coated material (GO−Sand composite) was prepared by soaking screened and washed sand particles (100 µm) with 3% graphene oxide aqueous solution. The coating process was done in two stages, first at a temperature of 105 ◦C for three hours then at 150 ◦C for two hours. FTIR spectroscopy was used to investigate the surface of graphite and graphene oxide. Adsorption of methylene blue and methyl orange dyes onto the prepared graphene oxide-coated sand was done experimentally using batch apparatus with controlled conditions of temperature and stirring. The effects of temperature and initial dye concentration for the adsorption process were examined. The analysis of adsorption equilibrium isotherms shows that the experimental data follows the Freundlich isotherm model with a coefficient of variance (R2) equal to (0.99). This indicates that the adsorption of both dyes onto the GO−sand was done on the heterogeneous surface with a multilayer of dye molecules. Furthermore, basic thermodynamic parameters for the adsorption of both dyes on GO−sand were calculated using the most well-known relationships. The results indicate that the process is spontaneous and exothermic as the values of Gibbs free energy changes lie between -37.078 and -24.231 kJ/mole and the values of enthalpy changes lie between -0.669 and -0.348 kJ/mole for methylene blue and methyl orange dyes. Finally, the activation energy for the adsorption process was determined using the Arrhenius equation and found to be equal to 28.643 kJ/mol and 20.224 kJ/mol for methylene blue and methyl orange adsorption, respectively. This proves the physical nature of dye adsorption on the surface of the adsorbent.

The attention of researchers in convective heat transfer by suspended nanoparticles in base fluids has grown lately to promote uncommon techniques for enhancing the thermal performance of fluids. In this study, the stability period and thermal properties of aluminum oxide (Al2O3), silicon dioxide (SiO2), and Al2O3–SiO2 hybrid were investigated at volume concentration 0.1vol.% dispersed in Distilled Water (DW) as a base fluid. For the hybrid nanofluid, the samples consisted of (0.025 vol.%Al2O3+0.075vol.%SiO2), (0.05vol.%Al2O3+0.05vol.%SiO2), and (0.075vol.%Al2O3+0.025vol.%SiO2). The two-step method was adopted to prepare the nanofluid samples by using an Ultrasonic device. Three different ultrasonication times were fitted for preparing the samples (1hr,2 hr, and 3 hr). The properties of single and hybrid nanofluids were evaluated at various temperatures (from 30 °C to 70 °C). The obtained results demonstrated that the dispersion of nanoparticles was homogeneous and more stable for a longer period for all samples that were prepared at 3 hr of ultrasonication process. Among all samples of nanofluids, SiO2/DW was found to be the most stable coolant. For all nanofluids, with an increase in temperature, the thermal conductivity and specific heat were increased significantly while density and viscosity were decreased.

The electric submersible pump (ESP) is a centrifugal pump with several stages. It\'s a dependable and efficient industrial lifting tool for lifting different amounts of fluids, and it\'s known for its adaptability and reliability. Electric submersible pumps are commonly used in onshore oil wells, as well as underground pumping and other applications. The pump\'s efficiency is evaluated under the control of various rotational speeds. The CFD approach is used in this analysis to analyze flow behaviors within the ESP at various flow speeds. ANSYS CFX program was approved to conduct and investigate a single-stage simulation of the GN7000 pump. The sensitivity of the network was determined, and the best mesh for the solution was chosen. The flow field was solved using the (SST, Unsteady-RANS) model with different rotational velocities (2500-3000-3500 cycle in this case). The test used two fluids with varying viscosities, and the findings revealed that the viscosity has an impact on efficiency as well. There is a high level of compatibility as compared to previous studies. This research presented a set of curves for efficiency and pressure and to know the extent of the effect of rotational speed on performance in general.

The depletion rate of conventional petroleum fuels is very fast. Gasoline is used as conventional fuel in the SI engine. Emissions from this fuel cause environmental pollution because it produces harmful emissions for the environment such as CO2, CO, HC, and NOx. Liquefied petroleum gas (LPG) has physical and chemical properties that make it a favorable fuel for IC engines. It can be used as a fuel alone or combined with gasoline with some minor engine modifications. The engine running on LPG showed improved performance - in terms of fuel economy, and overall efficiency compared to petrol. In addition, it is noted that LPG emissions are greatly lower than petrol. This work reviews the research conducted by previous researchers on LPG-powered SI engines under several working conditions.

The objective of this study is to evaluate the environmental impact of a brick factory complex in the west part of Al-Diwaneyah City. In the study, the site characteristics of the brick factories and compares them with the locational determinants in the Iraqi environmental laws were assessed. The Arc.GIS software has been used to process the spatial data and displays. The spatial analysis shows that the current site of brick factories does not conform to the current laws and regulations of Iraq. So, it eventually will create environmental problems for the city\'s expansion or factory development. Furthermore, air quality in the west of the city has been measured in some monitoring sites along the direction of the wind, close to the brick factories. The gas concentration measurement has continued for 12 days and 24 hours per day in the monitoring sites.SO2, NO2, CO, and NMHC were measured which showed that the maximum values of SO2, NO2, and NMHC were higher than the Iraqi standard while the CO value was very low.

Numerically investigated the electric double layer (EDL) Effects on the performance of the square microchannel heat exchanger (MCHE) at combined electro-osmotic and pressure-driven flow with compared pure pressure-driven with a hydraulic diameter (10 – 50) μm. We defined at any size (Dh) of microchannel heat exchanger become the impact of EDL is very slight with the studied effect of electric double layer thickness λ. The diluted water 1:1 potassium chloride (KCl) solution is used as a working fluid at an ionic concentration (10^(-4), 10^(-6)) M, silicon microchannel at zeta potential of surface -0.2 volt. A three-dimensional (3D) Poisson-Boltzmann equations and Naiver-stoke equations with applied electric field are solved by using the finite volume scheme in this work. The results show an increase in pressure drop of the microchannel heat exchanger at combined flow electroosmotic and pressure-driven flow with a percentage of 31.09 % at an ionic concentration 10^(-4) M and 42.71 % at 10^(-6) M, increase in pumping power, especially at low ionic concentration. Slight enhancement in average heat transfer rate and effectiveness due to an increase in average temperature difference. Decrease in overall performance at combined electroosmotic and pressure-driven flow compared with pure pressure driven.