Al-Nahrain Journal for Engineering Sciences <p><strong>Al-Nahrain Journal for Engineering Sciences</strong> is an open access academic specialized journal that evaluates and publish scientific papers in all engineering study fields submitted by researchers. It is a <strong>quarterly publication</strong> in English, issued in <strong>Baghdad</strong> under the responsibility of College of Engineering - Al-Nahrain University with the registration number<strong><em> ISSN</em> 2521-9154</strong> and <strong><em>eISSN</em> 2521-9162</strong>.</p> en-US <p><strong><span style="text-decoration: underline;">Author(s) Rights</span></strong></p> <ol> <li class="show">Each author retains the right to use the work for non-commercial purposes as well as for further research and spoken presentations.</li> <li class="show">Each author retains the right to use the illustrations and research data in his/her future work.</li> <li class="show">Only one offprint is provided free for each author. The authors can order offprints at the proof stage at certain rates depending on the number of additional copies required and the year of publication.</li> </ol> <p>&nbsp;</p> <p><strong><span style="text-decoration: underline;">Publisher Rights</span></strong></p> <p>The publisher of the journal has full rights for publication of the submitted manuscripts, electronic and facsimile formats and for electronic capture, reproduction and licensing in all formats now and in perpetuity in the original and all derivative works.</p> (Prof. Dr. Basim Obaid Hasan) (Asst. Prof. Dr. Ahmed Al-Hamaoy) Sat, 12 Mar 2022 00:00:00 +0000 OJS 60 The Effect of Bentonite (BNTN) Nanoclays with Multiple Weight Proportions on the Mechanical Properties of Polyacrylamide (PAM) Composites <p>The research includes studying the mechanical properties of BNTN/PAM nanocomposites under static and dynamic conditions. The BNTN/PAM nanocomposites were prepared with different weight fractions (0, 20%, 40%, 50% and 60%) by utilizing ball milling technique. Tensile strength, Charpy impact and Shore A hardness were performed to verify any improvements in these mechanical properties of nanocomposites. The results showed significant improvements in tensile, Charpy impact, Shore A hardness properties of nanocomposites at 50% weight fraction by approximately 335%, 1422%, 63% respectively. These results started decreasing after addition of 60% of nanoclays content to PAM composites. This mechanism indicates that the percentage of weight content of BNTN could affect the mechanical properties of nanocomposites.</p> Raghad Hamid Hilal Copyright (c) 2022 Al-Nahrain Journal for Engineering Sciences Sun, 03 Apr 2022 00:00:00 +0000 Single Bubble Breakage in Oil Under Stirring Conditions <p>An experimental study on single bubble breakage in the stirred tank in oil as a continuous phase was carried out for a range of stirring speeds (220 to 430 rpm). The results are compared with bubble breakage in water that was conducted by Hasan et al. (2021) to investigate the effect of physical properties of continuous phase on the breakage rate. The breakage events in the impeller were captured and analyzed using a high speed camera. It was found that the breakage rate represented by breakage probability and a number of produced daughter bubbles (fragments) are directly proportional with the stirring speed. The breakage probability and number of produced daughter bubbles in oil was noticeably lower than that in water indicating the role the continuous phase viscosity plays in reducing the breakage rate.</p> Basim Obaid Hasan Copyright (c) 2022 Al-Nahrain Journal for Engineering Sciences Wed, 13 Apr 2022 00:00:00 +0000 Improvement of Eye Tracking Based on Deep Learning Model for General Purpose Applications <p>The interest in the Eye-tracking technology field dramatically grew up in the last two decades for different purposes and applications like keeping the focus of where the person is looking, how his pupils and irises are reacting for a variety of actions, etc. The resulted data can deliver an extraordinary amount of information about the user when it's interlocked through advanced data analysis systems, it may show information concerned with the user’s age, gender, biometric identity, interests, etc. This paper is concerned about eye motion tracking as an unadulterated tool for different applications in any field required. The improvements in this area of artificial intelligence (AI), machine learning (ML), and deep learning (DL) with eye-tracking techniques allow large opportunities to develop algorithms and applications. In this paper number of models were proposed based on Convolutional neural network (CNN) have been designed, and then the most powerful and accurate model was chosen. The dataset used for the training process (for 16 screen points) consists of 2800 training images and 800 test images (with an average of 175 training images and 50 test images for each spot on the screen of the 16 spots), and it can be collected by the user of any application based on this model. The highest accuracy achieved by the best model was (91.25%) and the minimum loss was (0.23%). The best model consists of (11) layers (4 convolutions, 4 Max pooling, and 3 Dense). Python 3.7 was used to implement the algorithms, KERAS framework for the deep learning algorithms, Visual studio code as an Integrated Development Environment (IDE), and Anaconda navigator for downloading the different libraries. The model was trained with data that can be gathered using cameras of laptops or PCs and without the necessity of special and expensive equipment, also It can be trained for any single eye, depending on application requirements.</p> Ahmed Aamer Almindelawy, Mohammed H. Ali Copyright (c) 2022 Al-Nahrain Journal for Engineering Sciences Mon, 11 Apr 2022 00:00:00 +0000 Deposition of MgO Nanoparticles by Laser Pyrolysis <p>Magnesium oxide nanoparticles were deposited by laser pyrolysis process. Three types of lasers were employed CW CO<sub>2</sub>, Q-switched Nd-YAG (short pulses) and long pulses Nd-YAG lasers. The size and density of nanoparticles vary with laser energy, power, pulse duration and the scanning speed of the laser. In this method, MgO nanoparticles were deposited by a laser beam on a quartz substrate from aqueous solution of magnesium nitrate. AFM images reveal formation of small nanoparticle size of 24.5 nm with surface roughness 6.97nm by Q-switched Nd-YAG laser (10 ns) when the energy was 1J. While for CO<sub>2 </sub>laser, the smallest size was 18.8 nm at 0.4mm/s scanning speed with surface roughness 5.21nm at the same scanning speed. Moreover, long Nd-YAG pulses laser produces relatively larger average size of 37.5nm at 0.8ms pulse duration. The absorption spectra from UV-Visible spectroscopy were also conducted. The best absorption intensity was obtained at a wavelength ranging between 420-430 nm for both lasers. Finally, Thermal analysis using COMSOL Multiphysics software for the deposition process reveals that maximum temperature about 440Kfor Q-Switched Nd-YAG laser at 1J laser energy. While for RF CO<sub>2</sub> laser, the maximum temperature obtained at 0.4mm/s scanning speed is 850K.This work provides a good knowledge for the deposition of nanoparticles using laser beams.</p> Hala Mahmood Abdulwaahb, Bassam G. Rasheed, Hanadi H. Altawil Copyright (c) 2022 Al-Nahrain Journal for Engineering Sciences Sun, 03 Apr 2022 00:00:00 +0000 Effect of Crack Length on Stresses in a Plate with a Hole <p>The field of mechanics concerned with studying the propagation of cracks in materials is Fracture Mechanics. Technology systems are meant to withstand the loads to which they are likely to be exposed when in use. Material imperfections arising at the time of production or use of the material are, however, unavoidable and must therefore be taken into account. A stress intensity factor is a fracture parameter that defines the part failure. This paper study’s the effect of cracks on the stresses of rectangular plates having a hole in the center. The plate was subjected to tensile pressure at the top side while maintaining the bottom side fixed. The plate had four cracks distributed around the centered hole at 45o at each side. The effect of the length of the cracks on the resulted stresses and strains was investigated. Also, the effect of the position of the crack on the resulted stresses and strains was studied. Finite element models for the different plate cases were built using ANSYS software. The results showed that increasing the crack length resulted to increase the stresses and strains. The dimension of the plate width, height and thickness were 150 mm, 300 mm and 1 mm respectively, and the crack position was investigated for different crack lengths (5, 10, 15, 20, 25 mm) however the results were not steady as it looks that the crack lengths have changed the stress distribution over the plate.</p> Thaker Saleh Dawood, Younis Khalid Khdir Copyright (c) 2022 Al-Nahrain Journal for Engineering Sciences Fri, 08 Apr 2022 00:00:00 +0000 Hydrodynamics of Stirred Tank and Bubble Breakup Behavior Induced by Rushton Turbine <p>The hydrodynamics of stirred tanks and bubble breakup are crucial in gas-liquid flows, yet this system has not been well characterized for different operating conditions. In this work, the numerical method was used to investigate the hydrodynamics of six- flat blades impeller (Rushton turbine) and the results were employed to understand the bubble breakup behavior in the stirred tank. Simulation results of predicted flow pattern, power number, and the distribution of turbulence energy generated were performed with COMSOL Multiphysics. Numerical results showed good agreement with the experimental literature. The effect of rotational speed on bubble breakup behavior, such as breakage probability, the average number of daughter bubbles, and the breakage time was investigated using the high-speed imaging method. The main finding is that the breakage process occurs in the high energy area of high turbulence intensity, which is located within a distance equal to the blade width of a radius of (15-35 mm). The breakage probability (Bp) was found to be increased by 12.61 percent for a mother bubble of 4 mm at 340 rpm, with an average fragmentation of up to 22 fragments. Furthermore, the bubble breakage time was found to decrease with increasing impeller rotational speed, with an average value of 19.8 ms.</p> Anas Malik Mhawesh, Basim O. Hasan, Hussein Znad Copyright (c) 2022 Al-Nahrain Journal for Engineering Sciences Sun, 03 Apr 2022 00:00:00 +0000 Measurement of Cartilage Deformation in Intact Knee Joints under Compressive Loading <p>Many joints in the body depend on cartilage for their mechanical function. Since cartilage lacks the ability to self-heal when injured, treatments and replacements for damaged cartilage have been created in recent decades. The mechanical tests had an important role in the treatment and designing of the replaced cartilage. There are two types of cartilages in the knees: fibrocartilage (the meniscus, it is a special type of cartilage) and hyaline cartilage. Its mechanical properties are important because structural failure of cartilage is closely related with joint disorders. This study aimed to determine the stress-strain curve to give broader understanding of the material’s properties. The results of this study could help to develop computational models for evaluating mechanics of knee joint, predicting possible failure locations and disease progression in joints.<br />The study involved two specimens taken from bovine, the first was the articular cartilage with subchondral bone and the second was the meniscus cartilage each one loaded on a compressive testing machine to compute the displacement, and the force applied, enabling the calculation of the stress-strain curve of the material.<br />Specimen failure occurred in the articular cartilage surface at a force break of 73.8N and get force peak about 87.2 N. The meniscus cartilage failure had occurred at a force break of 29.2 N and get force peak about 34.9 N. </p> Balsam Muqdad Rashid, Sadiq Jaafar Hamandi, Eman Ghadban Khalil Copyright (c) 2022 Al-Nahrain Journal for Engineering Sciences Sun, 03 Apr 2022 00:00:00 +0000 Vibration Characteristics of the Bearing Rotor Shaft <p>In this work, the vibrations in the rotor-bearing system are studied experimentally and theoretically using ANSYS Workbench 2020 R1 software to compute the natural frequencies and mode shapes. In the experimental part, the LABVIEW software was used to examine the signal of the frequency domain values obtained from the accelerometer sensors, based on Fast Fourier Transform (FFT) technology and dynamic response spectrum. in the theoretical part, the natural frequencies are determined based on the finite element method for analyzing the system and knowing its behavior and vibration response level. The results showed that the level of vibration becomes higher at high rotational speeds, and it becomes large when the distances between the bearings are large, according to the bearing position and type used in the system. in this work can be concluded, the system is usually affected by the dynamic response around it and is difficult to separate from it, and the vibrations in the system can be controlled by adding an external damping source, which gives the system more stable. A system operating at high speeds can give a large vibration and an unbalanced response.</p> Karrar Baher, Qasim A. Atiyah, Imad A. Abdulsahib Copyright (c) 2022 Al-Nahrain Journal for Engineering Sciences Sun, 03 Apr 2022 00:00:00 +0000