Print ISSN: 1681-6900

Online ISSN: 2412-0758

Issue 1,

Issue 1


Membrane Bioreactor with External Side-Stream Membranes and High Cross Flow Velocity to Treat Municipal Wastewater

Majid A. Dixon; Talib R. Abbas; Mustafa H. Al-Furaiji; Raed H. Abed-Ali

Engineering and Technology Journal, 2020, Volume 38, Issue 1, Pages 1-8
DOI: 10.30684/etj.2021.168169

In this work, a pilot unit using side-stream MBR configuration was operated in BioFlow mode (i.e. no back pulse) and BioPulse mode (with intermittent back pulses) to treat municipal wastewater with relatively low MLSS. The results showed that the trans-membrane pressure (TMP) was less in the case of BioPulse over the whole period of system operation compared to that of BioFlow mode. However, the energy consumption per unit volume of permeated water is slightly higher in the case of BioFlow mode (3.4 kW.hr/m3) than that in the case of BioPulse mode (3.2 kW.hr/m3). Therefore, operation in BioPulse is preferable due to stable TMP caused by nearly fully recoverable fouling type, which results in lower chemical cleaning frequency. The MBR unit showed steady performance at a flux of 60 L/m2.hr. The system could achieve good water quality that satisfies Iraqi standards requirements for wastewater reuse or discharge to water resources

2D Model to Investigate the Morphological and Hydraulic Changes of Meanders

Jaafar S. Maatooq; Luay K. Hameed

Engineering and Technology Journal, 2020, Volume 38, Issue 1, Pages 9-19
DOI: 10.30684/etj.2021.168170

River engineering investigations require some level of hydrodynamic and morphologic analysis. The detailed of the hydraulic and morphologic features through meander evolution can be recorded by the numerical model spatially and temporally. The Center for Computational Hydro-science and Engineering, two- dimensional model (CCHE2D V3.29) was adopted to investigate the hydraulic and morphologic changes through meander’s evolution. Through the experimental work, a series of experiments runs were carried out through combining different geometric and hydraulic parameters to produce different experiment conditions. These parameters are flow rate, bed slope, and different initial incised and wide channels for both rectangular and trapezoidal sections. The CCHE2D model was calibrated and verified using two sets of experimental data. According to the computed values of statistical indicators, BIAS, NSE, and MAE of 0.0084, 0.96, and 0.0132 respectively for water level simulation, and 0.007,0.94, and 0.0182 respectively for bed level simulation, the calibrated Manning’s roughness which gives an acceptable agreement between simulated and measured water and bed levels was 0.029. The verification results were evaluated by the same statistical indicators of BIAS, NSE, and MAE of 0.09, 0.81, and 0.018, respectively, as evidenced by the statistical indicators, values that the CCHE2D model was reasonably capable of simulating the hydraulic and morphological changes through meander evolution.

Experimental Investigation on Electrochemical Grinding (ECG) for Stainless Steel 316

Abdullah J. Ghadban; Abbas F. Ibrahim

Engineering and Technology Journal, 2020, Volume 38, Issue 1, Pages 20-25
DOI: 10.30684/etj.2021.168171

This research focuses on material removal rate (MRR) and surface roughness during electrochemical grinding (ECG) for stainless steel 316. The effect of applied current, electrolyte concentration, gap size and spindle speed on machining performances has been studied. Where applied current used are (10, 20, 30, 40) A, electrolyte concentration used (100, 150, 200, 250) g/l, gap size used (0.2, 0.3, 0.4, 0.5) mm and spindle speed used (75, 150, 180, 280) rpm. Through the Taguchi design based experimental study the characteristic features of the ECG process are discussed. Where the maximum MRR can be obtained at 40 A of the current, 250 g/l of the concentration, 0.2 mm of the gap and 180 rpm of spindle speed. The best surface roughness can be obtained at 10 A of the current, 200 g/l of the concentration, 0.4 mm of the gap and 280 rpm of spindle speed..

Redrawing Operation a Star Shape from Cylindrical Shape Using Experimental and FE Analysis

Waleed Kh. Jawad; Ali T. Ikal

Engineering and Technology Journal, 2020, Volume 38, Issue 1, Pages 26-33
DOI: 10.30684/etj.2021.168172

The aim of this paper is to design and fabricate a star die and a cylindrical die to produce a star shape by redrawing the cylindrical shape and comparing it to the conventional method of producing a star cup drawn from the circular blank sheet using experimental (EXP) and finite element simulation (FES). The redrawing and drawing process was done to produce a star cup with the dimension of (41.5 × 34.69mm), and (30 mm). The finite element model is performed via mechanical APDL ANSYS18.0 to modulate the redrawing and drawing operation. The results of finite element analysis were compared with the experimental results and it is found that the maximum punch force (39.12KN) recorded with the production of a star shape drawn from the circular blank sheet when comparing the punch force (32.33 KN) recorded when redrawing the cylindrical shape into a star shape. This is due to the exposure of the cup produced drawn from the blank to the highest tensile stress. The highest value of the effective stress (709MPa) and effective strain (0.751) recorded with the star shape drawn from a circular blank sheet. The maximum value of lamination (8.707%) is recorded at the cup curling (the concave area) with the first method compared to the maximum value of lamination (5.822%) recorded at the cup curling (the concave area) with the second method because of this exposure to the highest concentration of stresses. The best distribution of thickness, strains, and stresses when producing a star shape by redrawing the cylindrical shape into a star shape.

The Effects of Anodizing Process on the Corrosion rate and Fatigue Life of Aluminum Alloy 7075-T73

Ibrahim M. AL-Sudani; Samir A. Al-Rabii; Dhafir S. Al-Fattal

Engineering and Technology Journal, 2020, Volume 38, Issue 1, Pages 34-42
DOI: 10.30684/etj.2021.168173

This research aims to study the effect of using the anodizing process on the corrosion rate, mechanical properties as well as the fatigue life for aluminum alloy (7075-T73), which is one of the most commonly used aluminum alloy in production of aircrafts, vehicles and ships structures. The anodizing process was employed through using sulfuric acid for time (20) min in a salty atmosphere. The mechanical properties and fatigue life of the AA7075-T73 were obtained before and after the anodizing process. All the results were listed in detailed tables and figures for comparison purpose. Generally, these results showed a decrease in corrosion rate by (155.06%) in comparison with untreated, an increase in hardness by (21.54%) and a slight decrease in fatigue life by (7.7%) due to anodizing for a time of 20 min at the stress level of (σa = 491.10 MPa). It was concluded that this technique could be applied on other aluminum alloys in order to know the magnitude of change in the mechanical characteristics and their fatigue life.

Numerical Study of Effect of Using Nanofluids Flowing in Simply Supported Pipes on Vibrations Characteristics

Kadhum A. Jehhef; Mohamed A. Siba; Hayder S. Abdulamir

Engineering and Technology Journal, 2020, Volume 38, Issue 1, Pages 43-56
DOI: 10.30684/etj.2021.168174

In general, internal vibrations within the pipelines caused by fluids being passing through a pipeline system can cause. These pipeline system can damage by the sudden amplified vibrations that weren’t considered at the design of the system, and flow induced vibrations resonate with the pipes natural frequency. Therefore, it is important to predict and identify the pipeline system vibrations during its lifetime. In this study by using MATLAB code as a CFD solver, it studied the forced and free vibrations caused by fluid flows at Reynolds number ranged as 0 < Re < 2500 for laminar flow and ranged as 104 < Re < 105 for turbulent flow. The working fluid has chosen as of (Al2O3, TiO2, SiO2 and water) with different nanoparticle volume fraction of (0 to 2% vol.). These fluids flow in simply supported pipe with different lengths and diameters. The results presented the effect of pipe and fluid parameter upon the fluid critical velocity and fundamental natural frequencies. The results showed that the pipe natural frequency increased with increasing with decreasing the pipe length and diameter. In addition, it showed that the pipe natural frequency decreased when using the different nanoparticle depressed in the water and with increasing the volume fraction.

Processing and Properties of ZA-27 Alloy Metal Matrix Hybrid Composite Reinforced with Nanonitrides

Fadhil A. Hashim; Niveen J. Abdulkader; Kateralnada F. Hisham

Engineering and Technology Journal, 2020, Volume 38, Issue 1, Pages 57-64
DOI: 10.30684/etj.2021.168175

In general, internal vibrations within the pipelines caused by fluids being passing through a pipeline system can cause. These pipeline system can damage by the sudden amplified vibrations that were not considered at the design of the system, and flow induced vibrations resonate with the pipes natural frequency. Therefore, it is important to predict and identify the pipeline system vibrations during its lifetime. In this study by using MATLAB code as a CFD solver, it studied the forced and free vibrations caused by fluid flows at Reynolds number ranged as 0 < Re < 2500 for laminar flow and ranged as 104 < Re < 105 for turbulent flow. The working fluid has chosen as of (Al2O3, TiO2, SiO2 and water) with different nanoparticle volume fraction of (0 to 2% vol.). These fluids flow in simply supported pipe with different lengths and diameters. The results presented the effect of pipe and fluid parameter upon the fluid critical velocity and fundamental natural frequencies. The results showed that the pipe natural frequency increased with increasing with decreasing the pipe length and diameter. In addition, it showed that the pipe natural frequency decreased when using the different nanoparticle depressed in the water and with increasing the volume fraction.

Identification and Management of Major Risk Factors in Construction of Healthcare Centers Projects

Khalil I. Wali; Mahmood M. Mahdi

Engineering and Technology Journal, 2020, Volume 38, Issue 1, Pages 65-73
DOI: 10.30684/etj.2021.168176

More attention is needed for healthcare centers projects and its development to change and improve the health situation in Iraq. The study of risk in this type of projects is essential to avoid the problems encountered during the project life cycle. This paper aimed to identify risk factors facing the construction of an advanced healthcare centers and to enhance the possible solutions based on the opinion of experts. For data collection, fifty-five risk factors were presented in a questionnaire form. The result showed that the major risk factor was government corruption, which has a direct influence on the economy and a negative impact on the infrastructure in the country and its development. The analysis showed that financial problems represent the highest risk during the years in all construction projects. Other considerable risk factors were time overrun, labor safety, as well as environmental risks, which are related to waste treatment. Other important risk factors were related to the ventilation system and air conditioning, also risk in providing continuous electrical power during the day. In term of risk groups, the five most effective ones were political, Economic, Safety, Operation & Maintenance and Construction risks.

Utilizing Artificial Intelligence to Collect Pavement Surface Condition Data

Hasan H. Joni; Imzahim A. Alwan; Ghazwan A. Naji

Engineering and Technology Journal, 2020, Volume 38, Issue 1, Pages 74-82
DOI: 10.30684/etj.2021.168177

Nowadays, data collection mechanisms are developed from ancient methods, including visual surveying to modern methods, which rely on digital imaging devices and laser scanning. This is expensive, delay of the pavement maintenance management and consuming of time. In this paper, a robust method proposed for automotive detection of linear distresses from real life movies of Iraqi highways. In the suggested method, common types of cracks, potholes and raveling are distinguished and collected automatically using high speed imaging techniques. The data extracted using the suggested method can be used for selecting priority of management maintenance of country roads and making decisions for treatment or rehabilitation.

Improvement of Image Steganography Using Discrete Wavelet Transform

Manal K. Oudah; Aqeela N. Abed; Rula S. Khudhair; Saad M. Kaleefah

Engineering and Technology Journal, 2020, Volume 38, Issue 1, Pages 83-87
DOI: 10.30684/etj.2021.168178

Recently the Discrete-Wavelet-Transform (DWT) has been represented as signal processing powerful tool to separate the signal into its band frequency components. In this paper, improvement of the steganography techniques by hiding the required message into the suitable frequency band is presented. The results show that the increase of the message length will reduce the Peak Signal to Noise Ratio (PSNR), while the PSNR increases with the increasing the DWT levels. It should be noted that the PSNR reduction was from -13.8278 to -17.77208 when increasing the message length from 161 to 505 characters. In this context, the PSNR is increased from -13.8278 to 7.0554 and from -17.7208 to 1.7901 when the DWT increased from level (1) to level (2).

Experimental and Numerical Simulation for Thermal Investigation of Oscillating Heat Pipe Using VOF Model

Anwar S. Barrak; Ahmed A. M. Saleh; Zained H. Naji

Engineering and Technology Journal, 2020, Volume 38, Issue 1, Pages 88-104
DOI: 10.30684/etj.2021.168179

This study is investigated the thermal performance of seven turns of the oscillating heat pipe (OHP) by an experimental investigation and CFD simulation. The OHP is designed and made from a copper tube with an inner diameter 3.5 mm and thickness 0.6 mm and the condenser, evaporator, and adiabatic lengths are 300, 300, and 210 mm respectively. Water is used as a working fluid with a filling ratio of 50% of the total volume. The evaporator part is heated by hot air (35, 40, 45, and 50) oC with various face velocity (0.5, 1, and 1.5) m/s. The condenser section is cold by air at temperature 15 oC. The CFD simulation is done by using the volume of fluid (VOF) method to model two-phase flow by conjugating a user-defined function code (UDF) to the FLUENT code. Results showed that the maximum heat input is 107.75 W while the minimum heat is 13.75 W at air inlet temperature 35 oC with air velocity 0.5m/s. The thermal resistance decreased with increasing of heat input. The results were recorded minimum thermal resistance 0.2312 oC/W at 107.75 W and maximum thermal resistance 1.036 oC/W at 13.75W. In addition, the effective thermal conductivity increased due to increasing heat input. The numerical results showed a good agreement with experimental results with a maximum deviation of 15%.

An Elaborate Review for Micro-Fin Heat Sink

Ibtisam A. Hasan; Sahar R. Fafraj; Israa A. Mohmma

Engineering and Technology Journal, 2020, Volume 38, Issue 1, Pages 105-112
DOI: 10.30684/etj.2021.168180

Heat sinks are low cost, the process of manufacturing reliability, and design simplicity which leads to taking into consideration various cutting-edge applications for heat transfer. Like stationary, fuel cells, automotive electronic devices also PV panels cooling and other various applications to improve the heat sinks thermal performance. The aim is to focus on some countless fundamental issues in domains such as; mechanics of fluids and heat transfer, sophisticated prediction for temperature distribution, high heat flux removal, and thermal resistance reduction. The outcome of this survey concluded that the best configuration of heat sinks has a thermal resistance about (0.140 K/W to 0.250 K/W) along with a drop of pressure less than (90.0 KPa) with a temperature gradient about 2 °C/mm. Heat sinks with square pin fins lead to enhance the effectiveness of heat dissipation than heat sinks with microcolumn pin fins. While other researches recommend the use of high conductive coating contains nano-particles. The present survey focuses on the researches about future heat sink with micro fin and the development to resolve the fundamental issues. The main benefits and boundaries of micro fins heat sink briefed.