Journal of Engineering

1

USING PROGRAMMING APPLICATION TO SOLUTION THE DIFFICULT AWARD OF CONTRACTS (SUPPLIED- CONSTRUCTION)

Sadee Abdul-Khalik Hassan

Pages: 849-870 English

Abstract

This article explores the use of programming applications to address the challenges associated with awarding contracts in supplied-construction projects. The research aims to leverage computer technology to identify and select the best offers submitted by contracting companies, considering factors such as labor wages, material prices, and project timelines. The study highlights the importance of effective management and planning to reflect the realities and capabilities of each contracting company. By utilizing software solutions, the proposed approach optimizes cost, duration, and quality, ensuring the successful completion of construction projects. The research includes field interviews with professionals and an analysis of tender documents to develop a comprehensive evaluation mechanism.

Keywords

Programming Application Contract Award Construction Projects Cost Management Time Management Quality Management Software Solutions Bid Evaluation Project Planning Optimization Techniques

2

EFFECT OF USING IRON SLAG ON FOUNDRY- MOLDING MIXTURE PROPERTIES

Khaled J. Mohammed

Pages: 871-884 English

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Abstract

This article investigates the impact of using iron slag as a replacement for silica sand in foundry-molding mixtures. The study evaluates the green compression strength and gas permeability of the mixtures with varying percentages of milled slag (10%, 20%, 30%, and 40%) compared to standard silica sand. Results indicate that incorporating slag improves the green compression strength in both green and dry states. However, dry specimens with slag content over 10% exceeded the testing machine\'s capacity. The findings suggest that iron slag can be effectively used in foundry-molding mixtures to enhance properties and reduce environmental pollution and transportation costs associated with slag disposal.

Keywords

Iron Slag Foundry-Molding Mixtures Green Compression Strength Gas Permeability Silica Sand Replacement Environmental Impact Waste Recycling Industrial Byproducts

3

SUSTAINABLE HOUSE BETWEEN ENVIRONMENT DETERMINERS AND DESIGN CONSIDERATIONS

Omar Hazem Khrofah

Pages: 885-904 English

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Abstract

This article explores the concept of sustainable housing, focusing on the interplay between environmental determinants and design considerations. The research highlights the importance of economical factors in achieving sustainability, particularly in housing projects. Various attempts and experiments in low-cost housing around the world are analyzed, emphasizing the need to adapt to local environmental conditions and climatic challenges. The study employs an analytical descriptive technique to evaluate several economical executive housing samples globally and assesses their applicability locally. The findings underscore the significance of integrating environmental and constructive aspects to achieve sustainable housing solutions.

Keywords

Sustainable Housing Environmental Determinants Architectural Design Energy Efficiency Low-Cost Housing Climate Considerations Construction Materials Green Building Practices

4

The effect of architecture staff in activate the technology of digital education in the Iraqi school of architecture

Layna Ghanem, Shukr Al-Hadidy

Pages: 909-929 English

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Abstract

This article examines the role of architecture staff in implementing digital education within the Iraqi School of Architecture. The study highlights the importance of enhancing architectural education through modern teaching methods and curriculum development. It explores the attitudes of architectural teachers towards digital education, their desire for more information about digital tools, and their willingness to integrate digital knowledge into the curriculum. The research aims to provide a comprehensive understanding of the current state of digital education in Iraqi architectural schools and to propose mechanisms for effectively activating digital education techniques. The findings emphasize the need for qualified staff and appropriate training to ensure the successful adoption of digital education in architectural programs.

Keywords

Digital Education Architecture Staff Iraqi School of Architecture Teaching Methods Curriculum Development Digital Knowledge Educational Technology Teacher Attitudes Digital Curriculum

5

TAGUCHI EXPERIMENTAL DESIGN AND ARTIFICIAL NEURAL NETWORK SOLUTION OF STUD ARC WELDING PROCESS

Nabeel K. Abid, Riyadh M.A Hamza, Ismail I. Al-kazaz

Pages: 4771-4794 English

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Abstract

This article presents a comprehensive study on optimizing the stud arc welding process using Taguchi experimental design and artificial neural networks (ANN). The research focuses on reducing the standard deviation of tensile strength while achieving the desired tensile strength joint. Key welding parameters such as welding time, welding current, stud material, stud design, sheet material, sheet thickness, sheet cleaning, and preheating were studied using a mixed L16 Taguchi experimental orthogonal array. The ANN model, designed using Matlab V6.5 software, is a supervised multi-layer feed-forward network with one hidden layer, consisting of 8 input neurons (control process parameters), 16 hidden neurons, and 2 output neurons (response variables). The Levenberg-Marquardt learning algorithm was employed for training the ANN. The study was conducted at the engineering college laboratory of Baghdad University, using the DABOTEKSTUD welding machine for 6 mm diameter studs. The results demonstrate the effectiveness of the combined Taguchi design and ANN approach in optimizing the stud arc welding process, achieving high tensile strength and process stability.

Keywords

Taguchi Experimental Design Artificial Neural Network (ANN) Stud Arc Welding Optimization Tensile Strength Welding Parameters Levenberg-Marquardt Algorithm Matlab Software DABOTEKSTUD Welding Machine USN and DIN Standards

6

BENDING MOMENT INFLUENCE SURFACES FOR RECTANGULAR CONCRETE PLATES SIMPLY SUPPORTED AT THREE EDGES AND BUILT-IN AT THE FOURTH EDGE

Sabah S. Razouki, Zena R. Al-Ani

Pages: 4795-4821 English

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Abstract

This article presents a series of bending moment influence surfaces for rectangular concrete plates simply supported at three edges and built-in at the fourth edge. The solutions are obtained analytically based on thin plate theory with small deflection using double Fourier series. The influence surfaces are presented for two observation points: the center of the plate and the midpoint of the built-in edge. A computer program was written in FORTRAN to generate the influence surfaces using the developed analytical solutions. The validity of the computer solution was confirmed by comparing its results with published results for zero Poisson's ratio, showing excellent agreement. The study also explores the application of the influence surfaces for cases involving a line load and a strip load. The results indicate that the bending moment influence surfaces depend on the actual value of Poisson's ratio, aspect ratio of the plate, and the position of the observation point.

Keywords

Bending Moment Influence Surfaces Rectangular Plates Simply Supported Edges Built-In Edge Thin Plate Theory Small Deflection Double Fourier Series Poisson's Ratio Aspect Ratio Observation Points

7

IMPLEMENTATION OF R-TECHNIQUE IN PRODUCTION PLANNING AND CONTROL

Zuhair Issa Ahmed, Fadhil Nassrallah Mahan

Pages: 4822-4241 English

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Abstract

This article explores the implementation of the R-Technique, also known as Response Surface Methodology (RSM), in production planning and control. The research focuses on automating engineering and management activities to achieve quick and accurate decision-making for production processes. A simulation system was constructed using Visual Basic to estimate future job volumes and determine the optimal process capacity of job shops. Realistic data from Electrical Industrial Company (EICO) factories were used to simulate the target production system. The R-Technique was employed to verify simulation results and obtain the optimum selection for process capacity, resulting in reduced waiting times and optimal exploitation of resources. The study demonstrates the effectiveness of R-Technique in enhancing production planning and control.

Keywords

Production Planning Scheduling Simulation Optimization Response Surface Methodology (RSM) R-Technique Job Shop Processes Visual Basic Process Capacity Cost Reduction

8

NUMERICAL STUDY OF TWO-DIMENSIONAL TRANSIENT NATURAL CONVECTION IN AN INCLINED SHALLOW POROUS CAVITY EXPOSED TO A CONSTANT HEAT FLUX

Jasim M. A. Al-lateef, Ayad K. Hassan

Pages: 4842-4853 English

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Abstract

This article presents a numerical study of two-dimensional transient natural convection in an inclined shallow porous cavity exposed to a constant heat flux. The study employs a finite difference method to solve the governing equations, with the energy equation solved using the alternating direct implicit (ADI) method and the stream function equation solved using the successive over relaxation (SOR) method. The results are presented for various Rayleigh numbers (20 to 500) and aspect ratios (2 to 4). The study examines the flow field, temperature distribution, and average Nusselt number in terms of the Rayleigh number, aspect ratio, and inclination angle of the cavity. The findings indicate that the convection becomes more vigorous as the inclination angle increases, and for high Rayleigh numbers, no steady unicellular flow can be maintained inside the cavity. The effect of the inclination angle on the Nusselt number is more pronounced at higher Rayleigh numbers.

Keywords

Numerical Study Transient Natural Convection Inclined Shallow Porous Cavity Constant Heat Flux Rayleigh Number Aspect Ratio Finite Difference Method Alternating Direct Implicit (ADI) Method Successive Over Relaxation (SOR) Method Flow Field Temperature Distribution Nusselt Number

9

HYDRODYNAMIC AND THERMAL TWO DIMENSIONAL BOUNDARY LAYERS DEVELOPMENT BETWEEN ROTATING TURBINE BLADES

Taif H. Salih, Ihsan Y. Hussain

Pages: 4858-4576 English

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Abstract

This article investigates the development of hydrodynamic and thermal boundary layers between rotating turbine blades. The study employs numerical analysis to solve two-dimensional incompressible boundary layer equations. A k-ε turbulence model is used to obtain eddy viscosity, and the finite volume method is applied with a staggered grid arrangement. The complex physical domain is addressed by transferring the original coordinate system to a non-orthogonal coordinate system. Calculations are performed for rotating two-dimensional turbine cascades at different speeds (1500 rad/s, 1800 rad/s, 1900 rad/s) and Reynolds numbers (5000, 10000, 100000) in subsonic flow conditions. The results, including vector and contour mappings of velocity, pressure, and heat transfer fields, as well as Nusselt number variations, are verified against published duct results and show good agreement. The findings highlight the significant impact of hydrodynamic and thermal boundary layers on fluid flow and heat transfer in rotating turbine blades.

Keywords

Hydrodynamic Boundary Layers Thermal Boundary Layers Rotating Turbine Blades Fluid Flow Heat Transfer Numerical Analysis Incompressible Boundary Layer Equations k-ε Turbulence Modeling Finite Volume Method Staggered Grid Arrangement Non-Orthogonal Coordinate System Subsonic Flow Nusselt Number

10

FLOW SEPARATION OF AXIAL COMPRESSOR CASCADE BLADES

Arkan Kh. Al-Taie, Sabah Faleh Habeeb

Pages: 4877-4896 English

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Abstract

This article presents an experimental and theoretical investigation of flow separation in an axial compressor cascade using NACA 65_(12)10 blades. The experimental work involved fabricating three wooden blades with varying spans for testing in smoke and wind tunnels. The cascade was tested at different stagger angles in a low-speed subsonic wind tunnel, and total and static pressures were measured. Flow separation was observed on the suction side of the lower blade, starting at a stagger angle of 4° and increasing with larger stagger angles. The theoretical work used FLUENT software to simulate the flow, showing good agreement with experimental results. The study highlights the impact of flow separation on compressor performance, with the static pressure ratio decreasing as the separation zone expands. The results provide valuable insights into optimizing compressor blade configurations to minimize flow separation.

Keywords

Axial Compressor Cascade Flow Separation Viscous Flow Wind Tunnel Testing Smoke Tunnel Visualization Stagger Angle Static Pressure Ratio FLUENT Simulation NACA 65_(12)10 Blade Subsonic Flow

11

ANALYSIS OF FUEL LONGTERM EFFECTS USING SUBCHANNEL CODES

E.A. Amin, M.Y. Abdul-Ahad

Pages: 4897-4909 English

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Abstract

This article investigates the long-term effects on nuclear fuel using subchannel codes, focusing on thermohydraulic analysis. The study aims to predict coolant channel temperature profiles at the core End Of Life and provide insights into the individual contributions to changes from Begin Of Life to End Of Life profiles. The effects of fuel swelling, rod bowing, and changes in physical properties are analyzed in detail using the COBRA3C code. The study integrates the COBRA3C code with the kinetic code AIREKMOD and a structural routine in a modular system, allowing for the coupling of different transient parameters under normal and abnormal operational conditions. The results demonstrate improved predictions of DNBR, highlighting the importance of considering long-term operational effects in reactor design and safety analysis.

Keywords

Subchannel Codes Fuel Long-Term Effects Thermohydraulic Analysis Coolant Channel Temperature Burnup Effects Thermal Stresses Fuel Swelling Rod Bowing Physical Property Changes DNBR (Departure from Nucleate Boiling Ratio)

12

SIMULATION OF TWO DIMENSIONAL FLOW AND CONJUGATE HEAT TRANSFER PROBLEM IN COOLED GAS TURBINE NOZZLE GUIDE VANE

AbdulKarim Ahmad Hassan, Mohammed Abdul-Nabi Aurybi

Pages: 4910-4929 English

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Abstract

This article presents a numerical study on the simulation of two-dimensional flow and conjugate heat transfer in a cooled gas turbine nozzle guide vane. The research employs a coupled treatment methodology to simultaneously solve the external flow (steady, two-dimensional, compressible, and turbulent flow) and conduction within the metal (steady, two-dimensional). The study validates the developed conjugate capability by comparing numerical results with experimental data for the NASA-C3X cooling guide vane. The findings demonstrate that the conjugate numerical methodology provides more accurate results than uncoupled treatments. Additionally, the cooling of the vane effectively reduces thermal stresses, particularly at the trailing edge, and extends the vane's lifespan for the same turbine inlet temperature and efficiency. The study underscores the importance of conjugate heat transfer simulation in gas turbine design and suggests future work with more complex geometries and cooling schemes.

Keywords

Two-Dimensional Flow Conjugate Heat Transfer Cooled Gas Turbine Nozzle Guide Vane Steady Flow Compressible Flow Turbulent Flow Internal Cooling Thermal Stresses Numerical Simulation Validation

13

COMPARATIVE ANALYSIS FOR LINK CROSS-SECTION OF MANIPULATOR ARMS

Ahmed Abdul Hussain Ali, Dler Obed Ramadhan

Pages: 4930-4953 English

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Abstract

This article presents a comparative analysis of the cross-sectional shapes of manipulator arms to achieve a high stiffness-to-weight ratio. The study analyzes stresses and deflections in robot arms using the ANSYS software package. The industrial robot analyzed consists of three arms with two degrees of freedom (2-DOF). Each arm's analysis was conducted separately, applying a static load at one end while fixing the other end. Various cross-sectional shapes with identical masses, lengths, and material properties were examined to determine the optimal shape. An optimization process was then conducted using MATHCAD software to find the dimensions that minimize deformation. The dynamic behavior of the optimized structure was studied to identify natural frequencies and mode shapes. The results indicate that a hollow circular section is optimal for the first link, while a square section is best for the other two links.

Keywords

Manipulator Design Structural Stiffness Robotics Robot Design Optimization Comparative Structural Analysis Finite-Element Analysis Structural Optimization ANSYS Software MATHCAD Software Natural Frequencies Mode Shapes

14

ANTISEIZURE CHARACTERISTICS OF LEADED ALUMINUM ALLOYS UNDER DRY SLIDING CONDITIONS

Dr. Akeel D. Subhi

Pages: 4954-4959 English

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Abstract

This article investigates the antiseizure characteristics of lead-aluminum alloys under dry sliding conditions. The study focuses on the effect of different lead percentages (1-20% Pb) added to a modified eutectic Al-12%Si alloy on wear rate and resistance. The alloys were tested by sliding them against a carbon steel disc at various sliding distances (2.24-40.37 km). Results indicate that the wear rate decreases and wear resistance increases with higher lead content in the alloy. Additionally, the wear rate increases linearly with sliding distance. The findings suggest that lead-aluminum alloys are effective in resisting seizure, making them suitable for various bearing applications.

Keywords

Lead-Aluminum Alloys Antiseizure Characteristics Dry Sliding Conditions Wear Rate Wear Resistance Tribological Alloys Eutectic Al-12%Si Alloy Carbon Steel Disc Sliding Distance

15

DEPENDABLE DISCHARGES OF THE UPPER AND MIDDLE DIYALA BASINS

Haitham A. Hussein

Pages: 4960-4969 English

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Abstract

This article investigates the dependable discharges of the upper and middle Diyala basins, focusing on water resource management and hydrology. The Diyala River, a major tributary of the Tigris River, runs through Iran and Iraq, draining an area of 32,600 km². The research compares the water balance study conducted by Russian researchers with recent data from the Derbendi-Khan dam for the period 1989-20071. Different probabilities (95%, 80%, and 50%) for each month (October to September) of the water year were considered using the empirical Wei Bull probability equation. The study concludes that a 50% probability is suitable for meeting the water requirements of the upper and middle basins1.

Keywords

50%) Mean Discharge Water Requirements 80% Diyala River Basin Water Discharge Derbendi-Khan Dam Water Balance Study Empirical Wei Bull Probability Equation Hydrology Water Resource Management Probabilities (95%

16

PARALLEL FUZZY LOGIC CONTROLLER IMPLEMENTATION USING MPICH2

Bakir A.R. AL-Hashemy, AboTalib H. Mahfoodh

Pages: 4970-4989 English

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Abstract

This article explores the implementation of a parallel fuzzy logic controller (FLC) using the MPICH2 package. The study presents two implementations: one with the rules stored inside the program and another with rules in a rulebase file. The execution times of these implementations, along with a MATLAB FLC implementation, are compared using different simulated FLCs. To reduce the rulebase searching time, a parallel FLC is implemented using C++ and MPI (Message Passing Interface). A cluster of four computers is used as the parallel environment. The execution time of the parallel FLC program is evaluated using servomotor control, Anti Skid System, and other simulated applications. The results show that decomposing the rulebase searching operation to more than one computer significantly reduces the execution time. The speedup and efficiency are studied using different numbers of computers, demonstrating the effectiveness of the parallel approach.

Keywords

Fuzzy Logic Fuzzy Logic Controller (FLC) Parallel Computing MPI (Message Passing Interface) MPICH2 C++ Programming Execution Time Servomotor Control Anti Skid System Speedup and Efficiency

17

BEARING CAPACITY OF SQUARE FOOTING ON GEOGRID-REINFORCED LOOSE SAND TO RESIST ECCENTRIC LOAD

Prof. Dr. Mosa J. Al-Mosawe, Dr. Aamal A. Al-Saidi, Faris W. Jawad

Pages: 4990-4999 English

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Abstract

This research investigates the bearing capacity of square footings on geogrid-reinforced loose sand subjected to eccentric loads. The study examines the effects of location eccentricity, depth of the first layer of reinforcement, vertical spacing, and the number and type of reinforcement layers. Experimental tests were conducted using a steel box model, and the results indicated significant improvements in bearing capacity with geogrid reinforcement. Specifically, bearing capacity improved by approximately 22% with one layer of reinforcement and 47.5% with two layers, for different eccentricity values. The findings highlight the effectiveness of geogrid reinforcement in enhancing the load-bearing performance of square footings on loose sandy soils.

Keywords

Bearing Capacity Square Footing Geogrid Reinforcement Loose Sand Eccentric Load Depth Ratio Vertical Spacing Reinforcement Layers Experimental Investigation

18

THEORETICAL SIMULATION OF STRESS-STRAIN RELATIONS FOR SOME IRAQI CLAYS USING THE ENDOCHRONIC MODEL

Mohammed Yousif Fattah, Maysam Th. Al-Hadidy, Akeel A.S. Al-Gharbawi

Pages: 5000-5020 English

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Abstract

This article presents a theoretical simulation of stress-strain relations for two Iraqi clays using the endochronic model. The endochronic model, a viscoplastic model without a yield surface, predicts the current stress state as a function of strain history through a time scale called "intrinsic time." The simulation showed that the model tends to overestimate strains for all cases studied, which may be attributed to the material parameters requiring a parametric study to determine their actual values for Iraqi clays. The findings highlight the need for further research to refine the model parameters for accurate predictions.

Keywords

Endochronic Model Stress-Strain Relations Iraqi Clays Viscoplasticity Intrinsic Time Constitutive Law Material Behavior Strain History Parametric Study

19

BUILDING OF AN EXPERT SYSTEM FOR WWTP OPERATION AND MANAGEMENT: RUSTIMIYAH SOUTH WWTP AS A CASE-STUDY

Prof. Dr. Rafa H. Al-Suhaili, M.Sc. Bashar J. Khalaf Al-Daami

Pages: 5021-5032 English

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Abstract

This article presents the development of an expert system designed to assist inexperienced operators in managing the Rustimiyah South Wastewater Treatment Plant (WWTP). The methodology involves three key steps: (i) creating decision trees for diagnosing operational problems, (ii) implementing the system in a real-based environment, and (iii) verifying its accuracy. The expert system, named ES-RS-WWTPO, utilizes knowledge acquired from literature and local experience through well-designed questionnaires. The system was tested in three operational states and demonstrated the ability to diagnose the plant's state with reasonable accuracy. The system was built using Visual Basic 6.0, providing a user-friendly interface for operators.

Keywords

Expert System Wastewater Treatment Plant (WWTP) Operation and Management Decision Trees Operational Problems Knowledge Acquisition Visual Basic 6.0 Environmental Engineering Real-Based System Verification

20

The Effect of Variation of Nonlinear Load on Power Factor of the AC Supply Network

Mohammed Abdulla Abdulsada, Prof. Dr. Ali A. Al-killidar, Dr. Ziad Al-Azawi

Pages: 5033-5047 English

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Abstract

This article evaluates the effect of nonlinear loads on the power factor of an AC supply network. A three-phase, six-pulse bridge converter is assembled and connected to a power supply through a three-phase AC voltage regulator. Theoretical analysis is performed using Fourier series analysis and Fast Fourier Transform (FFT) algorithms. Experimental measurements of distortion factor, displacement factor, and total power factor are recorded and compared with theoretical results. The study discusses power factor improvement relative to distortion and displacement factors, highlighting the importance of considering harmonic currents in system evaluations. The findings provide insights into optimizing power factor correction methods for AC supply networks with nonlinear loads.

Keywords

Nonlinear Load Power Factor AC Supply Network Harmonic Distortion Displacement Factor Distortion Factor Power Factor Correction Fourier Series Analysis Fast Fourier Transform (FFT) Electrical Engineering

21

INFLUENCE OF LENS ON MIGRATION OF DENSE NON-AQUEOUS PHASE LIQUID IN SATURATED ZONE

Prof. Dr. Waleed M. S. Kassim, Tamara Kawther Hussein, Dr. Ayad A. H. Al-Dulaimi

Pages: 5048-5060 English

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Abstract

This study investigates the control of Dense Non-Aqueous Phase Liquid (DNAPL) migration in a saturated zone with the presence of a relatively low permeability lens. A two-dimensional, finite-difference numerical model is developed to simulate the simultaneous movement of DNAPL and water through the saturated zone of the soil. The model treats air as an immobile phase at constant atmospheric pressure. The flow equations for DNAPL and water are formulated in terms of wetting and non-wetting fluid pressure heads, respectively. The finite-difference equations are solved fully implicitly using the Newton-Raphson iteration scheme with a Taylor series expansion to handle nonlinearity. The results indicate that the presence of a lens significantly controls the vertical movement of DNAPL in a heterogeneous porous medium. The findings are compared with results from previous studies, showing good agreement.

Keywords

Dense Non-Aqueous Phase Liquid (DNAPL) Saturated Zone Lens Permeability Numerical Model Finite-Difference Method Wetting and Non-Wetting Fluids Vertical Movement Environmental Engineering Groundwater Contamination

22

DRAG FORCE OF TWO SPHERES IN POWER LAW FLUIDS

Abbas H. Sulaymon, Abeer Ibrahim Alwared

Pages: 5061-5073 English

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Abstract

This research investigates the drag force on two spheres moving side by side and in line in non-Newtonian power law fluids. The study uses polyacrylamide (PAA) solutions with different concentrations and water for comparison. Various spheres made of stainless steel, glass, and plastic with different sizes and densities were tested. The drag coefficient was found to increase with the power law index for a constant Reynolds number, and the drag force increased with fluid density but decreased with sphere density. The results provide insights into the hydrodynamic interactions between spheres in non-Newtonian fluids and highlight the influence of fluid properties on drag force.

Keywords

Drag Force Power Law Fluids Non-Newtonian Fluids Hydrodynamic Interaction Reynolds Number Polyacrylamide Solution Stainless Steel Spheres Glass Spheres Plastic Spheres Fluid Density Sphere Density

23

REMOVAL OF METHYL TERTIARY BUTYL ETHER FROMSYNTHETIC WASTEWATER

Suondos K. A. Barno

Pages: 5074-5083 English

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Abstract

This article investigates the removal of Methyl Tertiary Butyl Ether (MTBE) from synthetic wastewater using chemical oxidation. The study examines the effects of reaction time and temperature (25-55°C) on the kinetics of MTBE oxidation in water with a concentration of 3000 ppm at pH levels ranging from 3 to 7. The experiments utilized a 1:1 ratio of hydrogen peroxide to Fenton’s reagent. Kinetic analysis was conducted to determine the reaction order and activation energy for the disappearance of MTBE during the reaction. The results indicate that increasing the reaction temperature and time enhances the degradation of MTBE, providing valuable insights for developing effective wastewater treatment methods.

Keywords

Methyl Tertiary Butyl Ether (MTBE) Synthetic Wastewater Chemical Oxidation Reaction Time Reaction Temperature Kinetic Analysis Fenton’s Reagent Hydrogen Peroxide pH Range Environmental Engineering

24

SHEAR CAPACITY OF CONCRETE PRISMS WITH INTERFACE JOINTS

Riyad Jawad Aziz

Pages: 5084-5097 English

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Abstract

This article investigates the shear capacity of concrete prisms with interface joints, which are commonly used in large engineering structures when concrete casting is interrupted. The study evaluates the horizontal shear strength at the interface between old and new concrete sections1. A total of 16 push-off tests were conducted to quantify the shear strength capacity, considering different interface surfaces (smooth and rough) with and without shear keys. The results indicate that rough surfaces with shear keys significantly enhance shear resistance, restoring up to 62% of the shear capacity compared to monolithic specimens1. The presence of shear reinforcement further improves the shear resistance at the interfaces.

Keywords

Shear Capacity Concrete Prisms Interface Joints Rough Surface Smooth Surface Shear Keys Shear Reinforcement Push-off Tests Construction Joints

25

INVESTIGATION OF THE EFFECT OF THE WAKE GENERATED BY ROTOR BLADES ON THE FLOW THROUGH STATOR PASSAGE FOR LOW PRESSURE TURBINE

Ihsan Y. Hussain, Ahmed W. Mustafa

Pages: 5098-5115 English

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Abstract

This article investigates the effects of incoming wakes from upstream rotors on the flow field within a low-pressure turbine cascade. The study employs numerical simulations to analyze the flow with and without inlet wakes. The rotor effect is represented by moving bars that generate passing wakes at the entrance of the stator. The flow field is studied by solving both steady and unsteady forms of the two-dimensional compressible Reynolds-averaged Navier-Stokes equations. A k-ε turbulence model is used to obtain eddy viscosity, and the Cartesian velocity components and pressure are analyzed on a collocated grid. The results show that wake passing produces an unsteady pressure field in the direction of rotor traverse. The comparison with experimental data shows a similar trend, except in the separation flow region due to turbulence model limitations.

Keywords

Wake Low Pressure Turbine Collocated Grid Unsteady Flow Reynolds-Averaged Navier-Stokes Equations k-ε Turbulence Model Finite Volume Method Body Fitted Coordinates Grid Generation SIMPLE Algorithm

26

CRACK DETECTION IN A ROTOR DYNAMIC SYSTEM BY VIBRATION MONITORING

Nabil H. H. Jawad, K. Z.

Pages: 5116-5128 English

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Abstract

This article explores the use of vibration monitoring as a technique for detecting cracks or defects in rotating mechanical systems. The study employs a local asymmetry crack model to simulate the presence of a transverse crack by increasing the flexibility of the shaft. The results show a decrease in resonance shaft speed with increasing crack depth ratio. The diagnostic method uses graphed results between natural frequency and shaft speed to detect cracks at various depth ratios (uncracked, 10%, 20%, and 30%) in a clamped-free rotor. The study also investigates the effects of crack position and mass location on the system's response, demonstrating that the 2x harmonic component of the system response is an effective target for monitoring.

Keywords

Vibration Monitoring Rotor Dynamics Crack Detection Transverse Crack Flexibility Resonance Shaft Speed Local Asymmetry Crack Model Diagnostics Clamped-Free Rotor Mass Location

27

USING PERSONAL COMPUTER FOR VIBRATION MEASUREMENTS AND ROTOR BALANCING

Roshen Tariq Ahmed, Ayad Mahmoud Salman, Waleed Khalid Ibrahem

Pages: 5129-5149 English

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Abstract

This article explores the use of personal computers for vibration measurements and rotor balancing. The research focuses on designing a digital instrument based on an industrial computer to measure vibration levels and rotor speed. The system displays the required amount of weight that must be added or removed from the rotor blades to reduce unbalance and associated vibrations. The study highlights the importance of addressing vibrational issues in heavy centrifugal machines, such as motors, turbines, and pumps, to prevent material fatigue, excessive wear, and noise. The implementation of this system demonstrates a practical approach to improving the balance and performance of rotating machinery.

Keywords

Vibration Control Helicopter Vibration Vibration Measurement Rotor Balance Digital Instrument Industrial Computer Weight Adjustment Unbalance Reduction Material Fatigue Noise Reduction

28

DESIGN AND IMPLEMENTATION OF INFORMATION SYSTEM FOR GENERAL DIAGNOSTIC AND REMEDY OF CASTING DEFECTS

Qasim M. Daws, Ban Bakir Jawad

Pages: 5150-5168 English

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Abstract

This article presents the design and implementation of an information system aimed at diagnosing and remedying casting defects. Casting defects are a significant issue in the casting process, and their diagnosis often relies on the inspector's experience and knowledge. The proposed system includes four methods for recognizing defects: selection of defect properties, picture-based diagnosis, a questionnaire method, and a combo box method for experienced workers. The system was developed using Visual Basic, allowing easy interaction with these methods. Defects are classified into seven main groups and further subdivided. Verification tests showed that the picture-based method is the simplest and fastest, as it requires users to compare casting defects with provided pictures. The system effectively diagnoses defects and suggests remedies, improving the accuracy and efficiency of the casting process.

Keywords

Casting Defects Diagnostic System Remedial Measures Information System Visual Basic Defect Classification Inspection Methods Picture-Based Diagnosis Questionnaire Method Combo Box Method

29

A STUDY OF FREE VIBRATION AND FATIGUE FOR CROSS-PLY CLOSED CYLINDRICAL SHELLS USING GENERAL THIRD SHELL THEORY (GTT)

Dr. Muhsen J. Jweeg, Dr. Wedad I. Alazzawy

Pages: 5170-5184 English

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Abstract

This article presents a study on the free vibration and fatigue behavior of cross-ply closed cylindrical shells using the General Third Shell Theory (GTT). The research develops a free vibration solution for laminated simply supported closed cylindrical shells and examines the critical in-plane fatigue load. The study involves developing equilibrium equations and analyzing the effects of tension or compression in-plane loads on the natural frequencies. The results show that the natural frequencies and in-plane fatigue load values are consistent with those obtained by other researchers. The findings contribute to the understanding of the dynamic behavior and fatigue performance of composite laminates, which is crucial for their application in various industries.

Keywords

Free Vibration Fatigue Cross-Ply Closed Cylindrical Shells General Third Shell Theory (GTT) Laminated Composite Shells Natural Frequencies In-Plane Fatigue Load Equilibrium Equations Structural Theories

30

EXPERIMENTAL STUDY OF FATIGUE CHARACTERISTICS OF LAMINATED COMPOSITE PLATES

Prof. Dr. Muhsin J. Jweeg, Dr. Ali Hussain Al-Hilli, Hussain Mohan Suker

Pages: 5185-5198 English

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Abstract

This article presents an experimental study on the fatigue characteristics of laminated composite plates made from glass fiber and polyester resin. The study investigates the fatigue damage under bending fatigue through specified deflection and measures the force response. Results are presented as S-N curves and in a logarithmic format. Fractography is used to characterize the fatigue damage, revealing a complex, interactive damage process that includes delamination, fiber breakage, matrix cracking, and fiber-matrix debonding. The findings provide valuable insights into the fatigue behavior of composite materials, which are crucial for their application in industries such as aircraft and marine engineering.

Keywords

Fatigue Characteristics Laminated Composite Plates Glass Fiber Polyester Resin Bending Fatigue S-N Curve Delamination Fiber Breakage Matrix Cracking Fiber-Matrix Debonding

31

PARAMETRIC STUDY OF LAMINAR FREE CONVECTION IN HORIZONTAL ANNULUS WITH AND WITHOUT FINS ON THE INNER CYLINDER

Asst. Prof. Dr. Saad M. Saleh, Jasim Mohammed Mehdi

Pages: 5199-5213 English

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Abstract

This article presents an experimental and numerical study investigating the heat transfer by natural convection in an air-filled annulus between two horizontal isothermal concentric cylinders, with and without annular fins on the inner cylinder. The inner cylinder surface is maintained at a higher temperature, while the outer cylinder surface is kept at a lower temperature. Experiments were conducted at various Rayleigh numbers and diameter ratios. The results indicate that increasing the diameter ratio significantly enhances the heat transfer rate, and attaching fins to the inner cylinder reduces the mean Nusselt number by 16.3% to 29.7% compared to the case without fins. The numerical study, using the finite difference method, showed good agreement with the experimental data, validating the results.

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Laminar Free Convection Horizontal Annulus Fins Inner Cylinder Heat Transfer Rayleigh Number Diameter Ratio Nusselt Number Steady State Numerical Study Experimental Study

32

FAULT TREE ANALYSIS AS A MODERN TECHNIQUE FOR INVESTIGATING CAUSES OF SOME CONSTRUCTION PROJECT PROBLEMS

Abbas M. Burhan

Pages: 5214-5224 English

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This article explores the application of Fault Tree Analysis (FTA) as a modern technique for investigating the causes of construction project problems. FTA is a graphical model that uses logic gates to describe combinations of individual faults that can lead to an undesired event. The assessment process can be divided into qualitative and quantitative analysis. As a case study, the article examines a building in Baghdad that experienced a punching shear problem. The research aims to introduce the principles of FTA and demonstrate its use in identifying and analyzing the causes of problems in construction projects. Additionally, it aims to compute the probability of occurrence of any problem or undesired event, providing a valuable decision support tool for project management.

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Fault Tree Analysis (FTA) Construction Project Problems Risk Assessment Qualitative and Quantitative Assessment Punching Shear Project Management Safety Risk Management Probabilistic Analysis Decision Support Tool

33

OPTIMIZATION OF DEM INTERPOLATION

Hussain Zaydan Ali, Ahmed Kasim Hameed AL-Akaby

Pages: 5225-5238 English

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This article explores the optimization of Digital Elevation Models (DEMs) through advanced interpolation techniques. DEMs, which are regular grids of elevation measurements, play a crucial role in various scientific, environmental, engineering, and military applications. Generating accurate and dense DEMs can be costly and time-consuming. This study evaluates DEMs produced from topographic maps and raster DEMs enhanced by single satellite images. A strategy using reflectance data to improve the accuracy of DEM interpolation is proposed and successfully tested. The results demonstrate the effectiveness of the proposed models in enhancing DEM resolution and accuracy.

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Digital Elevation Models (DEMs) Interpolation Spatial Enhancement Reflectance Data Optimization Algorithms Photogrammetry Remote Sensing Resolution Enhancement Topographic Mapping

34

IMAGE SEGMENTATION USING MULTIWAVELET TRANSFORM

Manal Fadel Younis

Pages: 5240-5248 English

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This article presents a region growing image segmentation method that unifies region and boundary information using a three-dimensional multiwavelet algorithm. The goal of segmentation is to simplify and/or change the representation of an image into something that is more meaningful and easier to analyze1. The proposed method overcomes the difficulties of traditional image segmentation by effectively characterizing different scales of image features. The region growing method is applied to segment the image, demonstrating improved accuracy in interpretation by utilizing image features1.

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Image Segmentation Multiwavelet Transform Region Growing Methods Seed Point Symmetry Orthogonality 3-D Multiwavelet

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REMOVAL OF DYES FROM TEXTILE EFFLUENT BY ADSORPTION ONTO OVEN DRIED ALUM SLUDGE

Rasha H. Salman

Pages: 5249-5262 English

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Abstract

This study investigates the removal of dyes from textile effluent using oven-dried alum sludge (ODS) as an adsorbent. Alum sludge was collected from the Al-Qadisiya water treatment plant, heated in an oven at 105°C for 24 hours, and then crushed to produce particle sizes of 1.18-2.36 and 4-4.75 mm. Batch experiments were conducted to study the effect of oven-dried alum sludge weight on the adsorption process and equilibrium isotherms, using 15-125 g/l of ODS for Direct Black and 15-175 g/l for Solar Brown, with a constant initial dye concentration of 10 mg/l and particle size of 4-4.75 mm. Fixed bed isothermal adsorption columns were used to study the effects of initial dye concentration, particle size, influent flow rate, and bed depth. The results showed that oven-dried alum sludge effectively adsorbed dyes with removal efficiencies ranging between 90% to 92%. The Freundlich, Langmuir, and Freundlich-Langmuir isotherms provided good fits for the adsorption capacity.

Keywords

Dye Removal Textile Effluent Adsorption Alum Sludge Oven Dried Batch Experiments Fixed Bed Adsorption Freundlich Isotherm Langmuir Isotherm Kinetics

36

COUPLED VERTICAL – TORSIONAL AND LATERAL FREE VIBRATION OF THIN-WALLED CURVED BEAM

Shatha Dhia Al Khazraji

Pages: 5263-5282 English

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Abstract

This study focuses on deriving the differential equations of motion for the free coupled vertical, torsional, and lateral vibrations of thin-walled curved beams with isotropic, open sections. The analysis is based on Hamilton's principle, which involves finding the potential and kinetic energy due to internal stresses and various types of movements. The study also considers the effect of restrained warping displacement. Three differential equations are derived for vertical, torsional, and lateral movements, and approximate solutions are developed using the method of multiple scales via a perturbation technique. The resulting natural frequencies and modes are compared with those calculated using the finite element approach (STAAD Pro. 2007) and other studies.

Keywords

Thin-Walled Curved Beams Free Vibration Differential Equation of Motion Hamilton's Principle Potential and Kinetic Energy Internal Stresses Vertical Movement Torsional Movement Lateral Movement Warping Displacement Perturbation Technique Natural Frequencies Finite Element Approach

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