Journal of Engineering

1

Technology and Architecture Analyzing Architecture from a Technological Standpoint

Nadia Abdul Majeed Al-salam, Saba Sami

Pages: 930-951 English

Abstract

This article explores the intersection of technology and architecture by analyzing architectural products from a technological perspective. Based on the philosophy of technology philosopher Carl Mitcham, the study identifies four manifestations of technology: Objects, Process, Knowledge, and Volition. These manifestations define architectural technology and the relationships between their components. The research introduces five analytical terms—materials and their processing, structure and its relations, detail building, tectonic values, and formal expression—that influence the formulation of architectural products. These terms provide a framework for technologically analyzing architectural works, offering insights into how technology shapes and is shaped by architectural design.

Keywords

Architectural Technology Carl Mitcham Materials Processing Structural Relations Architectural Detailing Tectonics Formal Expression

2

استخدام كسر الطابوق الطيني المعاد كبديل عن الحصى في انتاج بموك نمطي اقتصادي

سلام سماعن عبد الأحد

Pages: 952-974 English

Full Text Issues

Abstract

تتناول هذه الدراسة استخدام كسر الطابوق الطيني المعاد كبديل عن الحصى في إنتاج بلوك نمطي اقتصادي. تم تطوير بلوك نمطي خفيف الوزن (25x25x12.5 سم) يعادل في الحجم ثلاثة طوابق فنية (25x12.5x7.5 سم). يتم استخدام كسر الطابوق الطيني كمادة مخلوطة مع الرمل والإسمنت بدون استخدام الحصى. يمكن إنتاج هذا البلوك يدوياً أو ميكانيكياً. تم إنتاج عينات تحتوي على 40-65% من كسر الطابوق الطيني المعاد استخدامه. تم العثور على زيادة في معامل الحماية الحرارية بين 70-80% بينما تم الحصول على تقليل في التكلفة بحوالي نصف. توفر هذه الدراسة معلومات قيمة لتحسين كفاءة وفعالية عملية إنتاج البلوكات النمطية وتعزيز الاستدامة.

Keywords

استخدام المواد المعاد تدويرها الطابوق الطيني البلوك النمطي الاقتصادي الحصى الإنتاج اليدوي الإنتاج الميكانيكي الأوزان الخفيفة الحماية الحرارية الاستدامة

3

دراسة تجريبية لمبادل حراري صفائحي كمبرد هواء

أحمد أديب عبد الواحد

Pages: 975-988 English

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Abstract

تتناول هذه الدراسة تأثير تغييرات تيارات الهواء الرئيسي والثانوي على كفاءة الترطيب ومقدار الطاقة الحرارية المنتقلة عبر أسطح مبادل حراري صفائحي كمبرد هواء. تم استخدام جهاز تجريبي يحتوي على أدوات لقياس معدل تدفق الهواء ودرجة حرارة الهواء الجاف والرطب عند مدخل ومخرج المبادل. تم تثبيت كمية الهواء الثانوي مع تغيير كمية الهواء الرئيسي والعكس، وتم تحليل النتائج. تبين الدراسة أن زيادة كمية الهواء الثانوي بينما تقلل من كمية الهواء الرئيسي تزيد من كفاءة الترطيب بنسبة 16% وزيادة مقدار الطاقة الحرارية المنتقلة بنسبة 35%. من ناحية أخرى، زيادة كمية الهواء الرئيسي بينما تقلل من كمية الهواء الثانوي تقلل من كفاءة الترطيب بنسبة 12% وزيادة مقدار الطاقة الحرارية المنتقلة بنسبة 21%.

Keywords

مبادل حراري صفائحي كمبرد هواء تبريد هواء ترطيب غير مباشر كفاءة الترطيب مقدار الطاقة الحرارية المنتقلة تيار هواء رئيسي تيار هواء ثانوي

4

The Hidden Fields in Material that used for Building

أنفال مؤيد الحجيات

Pages: 989-1011 English

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Abstract

This article explores the hidden aspects of building materials and their impact on natural resources and the environment. It discusses the balance between conserving natural resources and reducing consumption to limit negative environmental effects. The study highlights the importance of sustainable construction practices and the role of materials in achieving this goal. It also examines the environmental consequences of material waste and the chemical interactions that contribute to pollution. The research aims to provide a comprehensive understanding of the forces that cause material changes over time and their effects on the environment, offering insights into sustainable building practices.

Keywords

Building Materials Natural Resources Conservation Sustainable Construction Environmental Impact Waste Management Material Properties Pollution Reduction

5

Design Criteria for Historic Fortresses Buildings in Iraq (Case Study Kirkuk Fortress )

Hadia S. Al-Hajjaj, Talib H. Al-Talib

Pages: 1012-1033 English

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Abstract

This article explores the architectural landmarks and design criteria of historic fortresses in Iraq, with a focus on the Kirkuk Fortress. The research aims to study the types of fortresses and their security defensive concepts, as well as to find characteristic samples of local experiences in dealing with fortified structures. The study provides a practical method and updated research to revive the urban and architectural heritage of the Kirkuk Fortress. The findings highlight the importance of continuous efforts to preserve and restore historic fortresses, ensuring they remain valuable cultural and historical landmarks.

Keywords

Historic Fortresses Design Criteria Kirkuk Fortress Architectural Landmarks Security Concepts Local Experiences Urban Architecture Reconstruction

6

السبل التخطيطية والتصميمية لتحقيق مبادىء االستدامة التقميدية في عمارة اإلسكان المحمية المستقبمية

محمد جمال الدين الربيعي, علياء محمود الحسن

Pages: 1034-1061 English

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Abstract

تتناول هذه المقالة السبل التخطيطية والتصميمية التي يمكن اتباعها لتحقيق مبادىء الاستدامة التقليدية في عمارة الإسكان المحمية المستقبلية. تهدف الدراسة إلى دمج المبادىء البيئية والتراثية في عملية التصميم المعماري والتخطيط الحضري لضمان الحفاظ على الموارد الطبيعية وتقليل الآثار البيئية السلبية. يتم استعراض تقنيات البناء المستدامة والحلول الإبداعية التي تسهم في تحقيق كفاءة الطاقة وتحسين جودة الحياة للسكان. تتناول الدراسة أيضاً أهمية الحفاظ على الهوية الثقافية والتراثية في تصميم العمارة السكنية، مع التركيز على محمية مستقبلية كمثال عملي لتطبيق هذه المبادى

Keywords

الاستدامة التقليدية عمارة الإسكان تخطيط حضري تصميم معماري محمية مستقبلية تقنيات بناء مستدامة الحفاظ على البيئة كفاءة الطاقة

7

REMOVAL OF OIL FROM WASTEWATER BY ORGANOCLAY PREPARED FROM IRAQI BENTONITE

Abbas H. Sulaymon, Jassim M. Kshash

Pages: 5778-5798 English

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Abstract

This study investigates the removal of oil from wastewater using organoclay prepared from Iraqi bentonite. The organoclay was synthesized by combining bentonite with hexadecyltrimethyl ammonium chloride, a quaternary amine. Wastewater samples were collected from the washing unit of the South Baghdad Gas Power Plant. The study examined the operating conditions of the batch process, including the quantity of organoclay, mixer speed, and adsorption time. The initial concentration of oil in the wastewater ranged from 230 to 1512 mg/L. X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) analyses showed significant differences between the prepared organoclay and natural bentonite, indicating the exchange of quaternary amine with calcium ions on the bentonite surface. After treatment, the oil concentration in the wastewater samples decreased to below 10 mg/L. Batch kinetics and isotherm studies were conducted using Lagergren and Ho kinetic equations and Freundlich, Langmuir, and BET isotherm models, respectively. The results demonstrate the effectiveness of organoclay in removing oil from wastewater, offering a promising solution for wastewater treatment.

Keywords

Oil Removal Wastewater Treatment Organoclays Bentonite Adsorption Hexadecyltrimethyl Ammonium Chloride Batch Process Kinetic Equations Isotherm Models

8

REGENERATION OF SPENT TRANSFORMER OIL

Abdul-Halim Abdul-Karim Mohammed, Mohammed Abbas Kadhum

Pages: 5799-5810 English

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Abstract

This study investigates the regeneration of spent transformer oil taken from Al-Dora power station. The regeneration process includes settling, filtration, thermo vacuum evaporation, and clay treatment. Settling was done by gravity to remove mechanical particles, while filtration was performed using filter paper. Thermo vacuum evaporation at 175°C and 241 mm Hg was used to remove dissolved water and light petroleum impurities. Clay treatment was employed for the final improvement of transformer oil properties. Iraqi clay, Algerian clay, and zeolite (A) were used, and their results were compared. The study examined the effect of clay-to-oil ratio and mixing time on water content, breakdown voltage, and acidity. The optimal conditions were found to be a clay-to-oil ratio of 2/100 and a mixing time of 5 minutes, resulting in water content of 32 ppm, breakdown voltage of 55 kV, and acidity of 0.028 mg KOH/g oil. Algerian clay provided better improvement compared to zeolite and Iraqi clay under the same conditions. Langmuir, Freundlich, and the combination of these adsorption isotherms were studied, with Freundlich isotherm best representing the adsorption of water on clay.

Keywords

Spent Lubricating Oil Transformer Oil Spent Mineral Oil Regeneration Insulating Oil Clay Treatment Settling Filtration Thermo Vacuum Evaporation Adsorption Isotherms

9

REMOVAL OF LEAD FROM SIMULATED WASTEWATER BY ELECTROCOAGULATION METHOD

Ahmed A. Mohammed, Muhanned Dhia Fadhil Al-Mureeb

Pages: 5811-5821 English

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Abstract

This study investigates the removal of lead ions from simulated wastewater using an electrocoagulation method. The process was conducted in an electrocoagulation cell equipped with aluminum anode and stainless steel cathode electrodes. The effects of various working parameters, such as pH, current density, initial lead concentration, electrodes surface area, gap between electrodes, and sodium chloride concentration, on the performance of the electrocoagulation cell were examined. The results showed that the highest removal efficiency was achieved at pH 9, with increased current density and decreased gap between electrodes. After 7 minutes of electrolysis at a flow rate of 0.025 l/min, the lead concentration decreased from 250 mg/L to 2.5 mg/L, corresponding to a 99% removal efficiency. This study demonstrates the effectiveness of electrocoagulation in removing lead from wastewater, offering a promising solution for wastewater treatment.

Keywords

Heavy Metals Wastewater Treatment Electrocoagulation Lead Removal Aluminum Electrode Stainless Steel Cathode pH Current Density Electrodes Surface Area Sodium Chloride Concentration

10

CONSTRUCTION WATER SUITABILITY MAPS OF TIGRIS RIVER FOR IRRIGATION AND DRINKING USE

Khalid Adel Abdulrazzaq, Ph.D, Wardah Sabah Kamil, M.Sc

Pages: 5822-5841 English

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Abstract

This study focuses on the construction of water suitability maps for the Tigris River, which is one of the major sources of surface water in Iraq. The research aims to evaluate the water quality for irrigation and drinking purposes by analyzing various parameters such as Total Hardness (T.H), sulfate (SO4-2), chloride (Cl-1), Total Dissolved Solids (T.D.S), Electrical Conductivity (EC), Calcium (Ca+2), Sodium Adsorption Ratio (SAR), pH, and Biological Oxygen Demand (BOD). The study adopts the Bhargava (1983) method to estimate the variation in water quality over time and location. Thirteen stations along the Tigris River were analyzed, starting from Feeshkabour and ending at Al-Qurna, using historical data from 2007/2008. The results indicate that the Tigris River water quality ranges from class I to II for irrigation use and class II to V for drinking use. The constructed maps provide a valuable tool for engineers and decision-makers to assess water quality and manage water resources effectively.

Keywords

Water Quality Index (WQI) Drinking Water Irrigation Tigris River Surface Water Water Quality Standards Pollutant Parameters Water Suitability Maps Environmental Monitoring

11

MULTI-BASIS WAVENET-BASED SPEED ESTIMATION IN DIRECT TORQUE CONTROLLED ASYNCHRONOUS MOTOR

Adel A. Obed

Pages: 5842-5854 English

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Abstract

This paper presents a proposed method for speed estimation of an asynchronous motor in a Direct Torque Control (DTC) system, based on a new architecture of a multi-basis wavenet model. The multi-basis model utilizes multi-set daughter wavelets to improve accuracy2. The structure and training algorithm of the proposed method are discussed, with the descent gradient method used for system structure and parameter initialization. The speed estimator and DTC asynchronous motor are combined based on the stator current signal, and the motor speed is estimated online during system operation1. Simulation results using Matlab/Simulink show that the proposed method is effective for speed estimation across various operating conditions, including starting, load conditions, and motor braking.

Keywords

Wavenet Multi-basis wavenet Direct Torque Control (DTC) Speed Estimation Asynchronous Motor Stator Current Signal Matlab/Simulink Dynamic Equations Sensorless Drive

12

HAND WRITTEN RECOGNITION USING NEURAL NETWORK ALGORITHM

Ammar O. Hoori

Pages: 5855-5862 English

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Abstract

This article addresses the problem of handwritten recognition using a neural network algorithm. The process involves two major steps: first, separating each character individually, and second, detecting the separated shape to its corresponding alphabetic letter. A backpropagation neural network with three layers is employed to detect and separate 26 English letters (A to Z). The method includes detecting the boundaries of each single written letter, resizing the separated character to fit the pre-trained neural network, recognizing the handwritten letter, and finally saving the recognized letter to a text file. The work is developed using Matlab 2008 version 7.6, and the results show good representations of letters contaminated by noise and non-trained letters.

Keywords

Character Recognition Neural Network Artificial Intelligence Backpropagation Handwritten Recognition

13

STATISTICAL ESTIMATION OF THE COMPRESSIBITY OF BAGHDAD COHESIVE SOIL

Bushra S. Al-Busoda, Abbas Jawad Al-Taie

Pages: 5863-5876 English

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Abstract

This study focuses on the statistical estimation of the compressibility of Baghdad cohesive soil by using empirical correlation equations and regression analysis. Due to the time and expense involved in performing consolidation tests, it is often desirable to obtain approximate values of compression and recompression indices from other soil properties that are more easily determined. The research compiled and evaluated numerous empirical correlation equations developed over the last six decades to estimate these indices. Routine laboratory tests of a large number of Baghdad soil samples were correlated with sophisticated laboratory consolidation results. The findings indicate that the compression index of Baghdad cohesive soil cannot be accurately estimated from Atterberg limits alone. Better values were obtained when multiple index properties were used in the regression analysis. This study provides valuable insights for preliminary evaluations of soil compressibility in geotechnical engineering.

Keywords

Compression Index Recompression Index Correlation Initial Void Ratio Natural Moisture Content Total Unit Weight Dry Unit Weights Empirical Correlation Equations Regression Analysis

14

ECG SLANTLET TRANSFORM WITH FPGA DESIGN

Zainab N. Ghanim

Pages: 5877-5891 English

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Abstract

This paper presents the application of the Slantlet Transform for feature extraction in ECG monitoring and diagnosis systems using FPGA design. The Slantlet Transform is used to convert continuous ECG signals into a form that can be classified by a classifier to detect cardiac abnormalities. The FPGA implementation involves programming in VHDL, and the results are compared with those obtained using Mat-Lab, showing similar accuracy and closeness to the original ECG signal. Using FPGA reduces the cost and time for building hardware systems for ECG monitoring and diagnosis, providing more flexibility compared to alternative approaches. The Mat-Lab program is used only for displaying the input and output discrete signals of the Slantlet Transform.

Keywords

ECG (Electrocardiography) Slantlet Transform FPGA (Field-Programmable Gate Array) Digital Signal Processing Feature Extraction Cardiac Abnormalities VHDL (VHSIC Hardware Description Language) Mat-Lab

15

THE INFLUENCE OF TENSION STIFFNENING MODELS ON THE DYNAMIC ANALYSIS OF REINFORCED CONCRETE SLABS

K.S. Mahmood, A.A. Abdul-Razzak, M.K. Kasim

Pages: 5892-5910 English

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Abstract

This study investigates the influence of tension stiffening models on the dynamic analysis of reinforced concrete slabs subjected to dynamic loads. The finite element method is employed using eight-node Serendipity degenerated elements, which are based on isoperimetric principles with modifications to relax excessive constraints. A layered approach is adopted to discretize the concrete through its thickness. Both elastic-perfectly plastic and strain hardening plasticity approaches are used to model the compressive behavior of the concrete. A tensile strength criterion is employed to initiate cracks, and a smeared fixed crack approach is used to model the behavior of cracked concrete. Five tension stiffening models are considered to evaluate their effects on the dynamic response of the slabs. The results show good agreement with other sources, demonstrating the importance of tension stiffening models in accurately predicting the dynamic behavior of reinforced concrete slabs.

Keywords

Dynamics Finite Elements Nonlinear Analysis Reduced Integration Reinforced Concrete Slabs Tension Stiffening Models

16

THE TRANSITION TO A PG GRADING SYSTEM FOR ASPHALT CEMENT IN IRAQ

Hamed M. H. Alani, Hamed M. H. Alani, Alaa S. Abbas

Pages: 5911-5931 English

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Abstract

This research explores the transition to a Performance Grade (PG) based system for evaluating asphalt cement used in paving works in Iraq. The study highlights the challenges faced, including the unavailability of test equipment and a lack of understanding of the necessary steps to implement the PG system. The research proposes a performance-based system using conventional test methods and available nomographs from literature. By analyzing climatic data, traffic data, and asphalt binder properties, the study aims to improve the specifications of asphalt in Iraq. Air temperature data from five cities (Mosul, Kirkuk, Rutba, Baghdad, and Basrah) over 18 years was reviewed to establish the required PG asphalt binder for each city. The study also tested currently used asphalt cements with penetration grades 40-50 and 60-70 using both conventional and Superpave methods. The results indicate that the proposed method aligns with the Superpave method, with penetration grade 40-50 equivalent to PG70-16 and penetration grade 60-70 equivalent to PG64-16. This transition promises significant improvements in pavement performance.

Keywords

Asphalt Cement Performance Grade (PG) Superpave Penetration Grades Asphalt Binder Climatic Data Traffic Data Nomographs Pavement Performance

17

COLORING OF GRAY-SCALE IMAGE USING FPGA

Ammar A. Hassan

Pages: 5932-5945 English

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Abstract

This paper introduces a mechanism for coloring gray-scale images using FPGA devices, which are suitable platforms for image processing applications due to their parallelism and pipelining capabilities. The proposed algorithm transfers color properties from a source colored image to a target gray-scale image by matching chromatic values of corresponding pixels. The implementation is done using VHDL on Xilinx FPGA devices, and the performance is evaluated using ISE 4.1i software1. The results demonstrate the effectiveness of the FPGA-based approach in real-time image processing, offering a promising solution for applications requiring high-speed data processing.

Keywords

Image Processing Gray-Scale Image FPGA (Field-Programmable Gate Array) VHDL (VHSIC Hardware Description Language) Xilinx Digital Signal Processing (DSP) Parallelism Pipelining

18

CORRELATIONS BETWEEN PHYSICAL AND MECHANICAL PROPERTIES OF AL-AMMARAH SOIL IN MESSAN GOVERNORATE

Rana Mohammed Al-Kahdaar, Abbas Fadhil Ibrahim Al-Ameri

Pages: 5946-5957 English

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Abstract

This paper investigates the correlations between various physical and mechanical properties of Al-Ammarah soil in Messan Governorate, southern Iraq. Data was collected from numerous geotechnical reports conducted under the supervision of the Consulting Engineering Bureau of Baghdad University. The study examines correlations between physical properties such as Liquid Limit (LL), Plasticity Index (PI), Liquidity Index (LI), Natural Water Content (W), and Void Ratio (e) with mechanical properties like Unconfined Compressive Strength (qu), Cohesion (cc), and Standard Penetration Test (SPT) values. Simple regression analysis was used to verify these correlations. The results indicate direct correlations between these parameters, which can be utilized in preliminary investigations and design stages for structural projects in the region.

Keywords

Al-Ammarah Soil Physical Properties Mechanical Properties Liquidity Index (LI) Plasticity Index (PI) Unconfined Compressive Strength (qu) Natural Water Content (W) Simple Regression Analysis Geotechnical Properties

19

DEVELOPING A METHODOLOGY TO PREPARE DESIGN ACCORDING TO PRODUCTION REQUIREMENT

Ghassan A. Al-Kindi, Kawakib A. K. Al-Mendwi

Pages: 5958-5981 English

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Abstract

This paper presents a methodology to develop a program that enables the preparation of design according to production requirements. The methodology involves creating algorithms to evaluate product design based on assembly and manufacturing requirements. The programs were applied to four case studies, two focusing on Design for Assembly (DFA) and two on Design for Manufacturing (DFM). The results showed that the DFA approach significantly reduced total assembly time and improved operation quality by lowering the probability of errors. However, the DFM approach requires further development to cover all factors affecting manufacturing processes. The study concludes that the proposed DFA and DFM programs are beneficial, but more research is needed to establish a comprehensive database to match the expertise of human experts in the field.

Keywords

Concurrent Engineering Design for Assembly (DFA) Design for Manufacturing (DFM) Production Requirements Algorithms Case Studies Assembly Time Quality Improvement

20

ON THE DYNAMICS OF DUAL-SPIN SPACECRAFT CONTAINING A NUTATION DAMPER

Ahmed A. Al-Ragihy, Alaa M. Hussein, Ali Mohammed Hussein

Pages: 5982-6000 English

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Abstract

This study investigates the dynamics of dual-spin spacecraft containing a proposed nutation damper, which consists of a ring filled with a viscous liquid with an offset center to improve damping. The equations of motion were developed using the Newton-Lagrange approach, resulting in dimensionless expressions involving the spacecraft's and damper's parameters. The nutation angle and time constant expressions were derived using the zero-order approximation technique. Equilibrium states and stability conditions were analyzed, and analytical expressions for the residual nutation angle were obtained. The analytical results were compared with numerical simulations using MATLAB, showing less than 3.6% error for the nutation mode and less than 8% error for the spin mode. The study demonstrates the effectiveness of the proposed damper in improving the dynamic and damping characteristics of dual-spin spacecraft.

Keywords

Dual-Spin Spacecraft Nutation Damper Viscous Liquid Newton-Lagrange Approach Equations of Motion Dimensionless Form Zero-Order Approximation Stability Condition MATLAB Simulation

21

BEHAVIOUR OF CROSS-PLY LAMINATED HYBRID COMPOSITE PLATES WITH AN INCLINED CRACK SUBJECTED TO A UNIFORM TEMPERATURE RISE

Majid H. Faidh-Allah

Pages: 6001-6011 English

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Abstract

This paper presents a thermal buckling analysis of symmetric and antisymmetric cross-ply laminated hybrid composite plates with an inclined crack subjected to a uniform temperature rise. The mathematical formulation employs the first-order shear deformation theory in conjunction with the variational energy method. The eight-node Lagrangian finite element technique is utilized to obtain the thermal buckling temperatures of hybrid composite laminates. The study investigates the effects of crack size and lay-up sequences on the thermal buckling temperatures for symmetric and antisymmetric plates under various boundary conditions. The results, presented in graphical form, indicate that the buckling temperature increases with crack length and perforation angle. This research provides valuable insights into the stability of hybrid composite plates under thermal loading conditions.

Keywords

Hybrid Composite Plates Thermal Buckling Finite Element Method First-Order Shear Deformation Theory Variational Energy Method Crack Size Lay-Up Sequences Boundary Conditions

22

WOVEN FACTOR FOR THE MECHANCIAL PROPERTIES OF WOVEN COMPOSITE MATERIALS

Kadhim H. Ghlaim

Pages: 6012-6027 English

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Abstract

This study investigates the mechanical properties of woven composite materials, focusing on the woven factor, which quantifies the influence of weave patterns on the material's performance. The research evaluates tensile strength, Young's modulus, and Poisson's ratio for composites reinforced with E-Glass, Kevlar, and Carbon fibers, using both epoxy and polyester resins as matrices. The woven factors were calculated by comparing the mechanical properties of woven composites with those of unidirectional composites made from the same materials. The results indicate that Kevlar composites exhibit higher woven factors compared to E-Glass and Carbon composites, and epoxy-reinforced composites perform better than polyester-reinforced ones. This study provides valuable insights into the design and optimization of woven composite materials for various applications.

Keywords

Woven Composite Materials Tensile Strength Young's Modulus Poisson's Ratio E-Glass Fiber Kevlar Fiber Carbon Fiber Epoxy Resin Polyester Resin

23

PULSE WIDTH MODULATION FOR HIGH PERFORMANCE HYBRID STEPPER MOTOR

Pages: 6028-6047 English

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Abstract

This study investigates the mechanical properties of woven composite materials, focusing on the woven factor, which quantifies the influence of weave patterns on the material's performance. The research evaluates tensile strength, Young's modulus, and Poisson's ratio for composites reinforced with E-Glass, Kevlar, and Carbon fibers, using both epoxy and polyester resins as matrices. The woven factors were calculated by comparing the mechanical properties of woven composites with those of unidirectional composites made from the same materials. The results indicate that Kevlar composites exhibit higher woven factors compared to E-Glass and Carbon composites, and epoxy-reinforced composites perform better than polyester-reinforced ones. This study provides valuable insights into the design and optimization of woven composite materials for various applications.

24

EFFECT OF INNER BOUNDARIES GEOMETRY ON NATURALCONVECTION HEAT TRANSFER IN HORIZONTAL ANNULI

Kadhum A. Jehhef, Faris A. Badawy

Pages: 6064-6071 English

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Abstract

This study investigates the effect of inner boundaries geometry on natural convection heat transfer in horizontal annuli. The research employs an analytical modeling approach to study free convective heat transfer between a circular outer cylinder and a heated inner envelope with different cross-sectional shapes (circular, triangular, square, and hexagon). The composite model is based on asymptotic solutions for three limiting cases: pure conduction, laminar boundary layer convection, and transition flow convection. Laminar conditions up to a Rayleigh number of
5
×
10
4
were investigated. MATLAB simulations were used to study the effects of annulus diameter ratio, Rayleigh number, and cross-sectional geometries on the Nusselt number and the ratio of thermal conductivity. The results indicate that the circular inner boundary geometry shows a slight increase in the Nusselt number with increasing Rayleigh number, while the hexagon geometry exhibits higher Nusselt number values compared to triangular and square geometries. The study provides valuable insights into optimizing heat transfer in horizontal annuli with different inner boundary geometries.

Keywords

Hexagon Rayleigh Number Nusselt Number Thermal Conductivity MATLAB Simulation Natural Convection Heat Transfer Horizontal Annulus Inner Boundary Geometry Circular Square Triangular

25

SURFACE TEMPERATURE EFFECT ON THETHERMOHYDRODYNAMIC PERFORMANCE OF JOURNALBEARING IN HEAVY DUTY MACHINERY

Basim A. Abass, Basim A. Abass, Basim R. Sadiq

Pages: 6071-6084 English

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Abstract

This study investigates the effect of surface temperature on the thermohydrodynamic performance of journal bearings used in heavy-duty machinery. A steady-state thermohydrodynamic model (THD) is developed, incorporating the generalized Reynolds equation, energy equation in the oil film, and heat transfer equation in the bush and shaft. These equations are solved simultaneously to analyze the impact of shaft temperature on bearing performance. The results indicate that shaft temperature significantly affects the performance of the bearing. MATLAB simulations were used to validate the analytical results, demonstrating the importance of considering thermal effects in the design and operation of journal bearings in heavy-duty machinery.

Keywords

Thermohydrodynamic Performance Journal Bearing Heavy Duty Machinery Steady State Model Generalized Reynolds Equation Energy Equation Heat Transfer Equation Shaft Temperature MATLAB Simulation

26

EXPERMENTAL INVESTIGATION OF TEMPERATUREFOR STIR FRICTION WELDING DISTRIBUTION

Qasim M. Doos, Suhair G. Hussein

Pages: 6085-6099 English

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Abstract

This paper presents an experimental investigation of temperature distribution during stir friction welding (FSW) of Aluminum alloy (7008). The study examines the effects of key welding parameters, such as rotational speed (tool speed) and welding speed (liner speed), on the temperature distribution within the weld zone. The results indicate that rotational speed has a significant impact on temperature distribution, with higher speeds leading to increased temperatures. Conversely, welding speed shows an inverse relationship with temperature increase. Theoretical peak temperatures were estimated using the Bakingham
????
theorem, establishing a relationship between dimensionless heat input and peak temperature. Mechanical testing, including tensile tests, was conducted on welded specimens to evaluate the effect of temperature distribution on the mechanical properties of the alloy. The findings demonstrate that Aluminum alloy (7008) is weldable using FSW, achieving a maximum weld efficiency of 81% with parameters of 880 rpm rotational speed and 1 mm/sec welding speed. The study concludes that successful welding occurs when the temperature reaches 75-80% of the melting point of the material.

Keywords

Friction Stir Welding (FSW) Temperature Distribution Rotational Speed Welding Speed Aluminum Alloy (7008) Peak Temperature Tensile Test Weld Efficiency

27

NUMERICAL AND EXPERIMENTAL INVESTIGATION ON THE EFFECT OF RESTRICTION SHAPE ON CHARACTERISTICS OF AIRFLOW IN A SQUARE DUCT

Khalid A. H. Ismael, Ikhlase M. Fayed, Hanaa Abdul Hadi

Pages: 6100-6122 English

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Abstract

This study investigates the effect of restriction shape on the characteristics of airflow in a square duct through both numerical and experimental approaches. The numerical approach employs the finite volume method to solve elliptic partial differential equations modeling turbulent flow using the
????
−
????
model and wall function concept. Experimental test rigs constructed from Perspex and equipped with a five-hole pressure probe were used to measure the three components of airflow velocity vectors in space. The results indicate that the total pressure drop depends on the shape and position of the restriction. The pressure drop coefficient due to the restriction shape and position (
????
????
) is influenced by the blockage area ratio (
????
????
) and the ratio between the wetted perimeter to the free remainder perimeter (
????
????
/
????
????
), but not by the Reynolds number. The study provides valuable insights into optimizing airflow characteristics in duct systems with different restriction shapes.

Keywords

Airflow Square Duct Restriction Shape Turbulent Flow Reynolds Number Pressure Drop Finite Volume Method Experimental Test Rig Perspex Five-Hole Pressure Probe

28

VERIFICATION OF LAMINATE COMPOSITEPLATE SIMULATION UNDER COMBINED LOADINGS THERMALSTRESSES

Nabeel K. Abid AL-sahib, Adnan N. Jameel, Louay S. Yousuf

Pages: 6124-6142 English

Full Text Issues

Abstract

This study investigates the thermal cyclic loading phenomena of laminate composite plates fabricated from woven roving fiberglass and polyester. The plates were subjected to a temperature gradient thermal shock of 75°C for ten cycles at different conditioning times to study the effect of thermal fatigue. The research employs both theoretical and finite element methods, with the theoretical approach involving derived equations for stress distribution and normal deflection evaluation under dynamic analysis. The finite element analysis was conducted using ANSYS Ver. 9, and the results were compared with experimental data and Levy solution results. The study found that the relative reduction in normal deflection and dynamic load factor during cooling to -15°C were 78.593% and 9.421%, respectively. The findings highlight the importance of considering thermal stresses in the design and analysis of laminate composite plates under combined loadings.

Keywords

Laminate Composite Plate Combined Loadings Thermal Stresses Thermal Fatigue Bending Moment (Mo) In-plane Force (Nxx) Finite Element Analysis ANSYS Simulation Levy Solution Dynamic Analysis

29

NUMERICAL AND EXPERIMENTAL INVESTIGATIONOF STEAM FILM CONDENSATION ON A VERTICAL TUBE

Wail S. Sarsam, Luma F. Ali

Pages: 6144-6163 English

Full Text Issues

Abstract

This study investigates the film condensation of steam on a vertical tube both numerically and experimentally. A mathematical model was developed based on the conservation laws of mass and energy, Nusselt's analysis of film condensation, and empirical equations from the literature. A simulation program in FORTRAN was created to simulate the film condensation process, incorporating a complete steam tables subprogram. The experimental work was conducted using a steam condensation test bench, recording inlet and outlet cooling water temperatures, steam temperature and pressure, tube surface temperature, and cooling water flow rate. The numerical program calculated the tube surface temperature distribution, cooling water temperature distribution, local heat transfer rate, local condensation heat transfer coefficient, condensate boundary layer thickness distribution, total heat transfer rate, and average condensation heat transfer coefficient. The study examined the effects of various parameters, such as steam temperature, steam-surface temperature difference, and the presence of non-condensable gas, on the condensation heat transfer coefficient. The experimental data showed good agreement with the numerical results, validating the computational program's suitability for simulating steam condensation on a vertical tube.

Keywords

Steam Film Condensation Vertical Tube Numerical Simulation Experimental Investigation Conservation Laws of Mass and Energy Nusselt's Analysis FORTRAN Simulation Cooling Water Flow Rate Condensation Heat Transfer Coefficient Non-Condensable Gas

30

PARAMETRIC STUDY OF SUCTION OR BLOWINGEFFECTS ON TURBULENT FLOW OVER A FLATPLATE

Najdat Nashat Abdulla, Sajida Lafta Ghashim, Jassim

Pages: 6165-6185 English

Full Text Issues

Abstract

This paper presents a numerical study on the effects of suction or blowing from a spanwise slot on the turbulent boundary layer flow over a flat plate. The governing partial differential equations, including continuity, momentum, energy, and the
????
−
????
turbulence model, were derived and solved using a finite volume method with a staggered grid and modified SIMPLE algorithm. The study tested uniform suction or blowing velocity ratios of
????
/
????
∞
=
±
0.0185
,
±
0.0463
,
±
0.0925
m/s for a Reynolds number of
1.36
×
10
7
. The slot positions were varied at
????
/
????
=
1
/
4
,
1
/
2
,
3
/
4
from the leading edge, and the slot widths were
0.12
,
0.2
,
0.28
m. The results showed that uniform blowing at
????
/
????
=
1
/
4
significantly reduced the skin friction coefficient, wall shear stress, and boundary layer thickness, while increasing the boundary layer shape factor. Reynolds stress
????
????
decreased more than
????
????
and
????
????
, and mean velocity profiles in wall coordinates and dimensionless distance
????
+
,
????
+
decreased. Similar behavior was observed when the slot was moved downstream to
????
/
????
=
1
/
2
or
3
/
4
. The study provides insights into optimizing flow control techniques for turbulent boundary layers.

Keywords

Suction or Blowing Turbulent Flow Flat Plate Spanwise Slot Reynolds Number Skin Friction Coefficient Wall Shear Stress Boundary Layer Thickness Reynolds Stress Mean Velocity Profiles

31

FORGEABILITY OF 25%GRPOM ( CELCONR ) TOPRODUCE SPUR GEAR UNDER HOT CONDITIONSTHROUGH SLOW SPEED PRESS.

Talib H. Rashid

Pages: 6186-6197 English

Full Text Issues

Abstract

This research investigates the forgeability of a preheated billet of 25%GRPOM (CelconR) plastic through a closed die forging technique to produce a spur gear under hot conditions. The process involves heating the billet and die assembly to 100°C to achieve the complete gear shape. The study discusses the type of deformation involved and tests the product to ensure no internal or external defects, with an improvement in mechanical properties. The cycle time to produce the complete shape was two minutes. The results demonstrate the feasibility of using 25%GRPOM (CelconR) for forging spur gears under hot conditions, highlighting the potential for producing high-strength and high-stiffness components through this method.

Keywords

Forgeability 25%GRPOM (CelconR) Spur Gear Hot Conditions Slow Speed Press Closed Die Forging Preheated Billet Mechanical Properties Deformation

32

REMOVAL OF DIRECT BLUE DYE IN TEXTILEWASTEWATER EFFLUENT BY ELECTROCOAGULATION

Atheer M. Ghalib

Pages: 6198-6205 English

Full Text Issues

Abstract

This study investigates the removal of direct blue dye from textile wastewater effluent using the electrocoagulation method with aluminum electrodes in a bench-scale electrochemical system. The research examines the effects of current density, NaCl concentration, and electrocoagulation time on the color removal efficiency. The results indicate that increasing the current density enhances the color removal efficiency but also increases energy consumption. Conversely, increasing the NaCl concentration improves the color removal efficiency while reducing energy consumption. High dye concentrations require longer electrocoagulation times to achieve the same efficiency as lower dye concentrations. With a current of 0.35 amps and a NaCl concentration of 2 g/l, over 93% efficiency was achieved in 14 minutes. This study provides valuable insights into optimizing the electrocoagulation process for dye removal in textile wastewater treatment.

Keywords

Electrocoagulation Direct Blue Dye Textile Wastewater Aluminum Electrode Color Removal Efficiency Current Density NaCl Concentration Electrocoagulation Time Bench-Scale System

33

UTILIZATION OF THOMAS MODEL TO PREDICT THEBREAKTHROUGH CURVES FOR ADSORPTION AND IONEXCHANGE

Yasmen A. Mustafa, Shahlaa E. Ebrahim

Pages: 6206-6223 English

Full Text Issues

Abstract

This study explores the utilization of the Thomas model to predict the breakthrough curves for adsorption and ion exchange processes in fixed-bed systems. The Thomas model, based on second-order reaction kinetics and the Langmuir isotherm, provides a general analytical solution for the design equations of these processes. A computer program was developed using MATLAB 7.0 to solve the Thomas model and compare its predictions with experimental data. Four sets of experimental data were tested, representing the sorption of o-cresol from water by activated carbon, acetic acid from air by activated carbon, phenol from water by natural zeolite, and trichloroethylene from air by zeolite-5A. The results demonstrate a good agreement between the model predictions and the experimental data, validating the Thomas model's capability to predict breakthrough curves for adsorption and ion exchange processes.

Keywords

Thomas Model Breakthrough Curves Adsorption Ion Exchange Fixed Bed Second-Order Reaction Kinetics Langmuir Isotherm MATLAB Simulation Experimental Data

34

FREE VIBRATION RESPONSE ANALYSIS OF BURIEDCYLINDRICAL STORAGE TANKS

Adrian F. Ali, Hussein Mahmood Ali

Pages: 6242-6266 English

Full Text Issues

Abstract

This study presents a reliable and effective idealization scheme for the free vibration analysis of buried cylindrical storage tanks. The three-dimensional problem is transformed into a two-dimensional one using a semi-analytical finite element procedure. Conical shell of revolution elements are used to represent the cylindrical wall, top plate, and bottom plate of the tank. The combined effect of structure-soil-fluid interaction is of primary importance. The soil medium is idealized by the elastic half-space model, with linear springs representing the structure-soil interface, added masses, and viscous dampers of the soil. The liquid region is treated analytically, and analytical integration is used to obtain the added stillness and mass matrices for hydrostatic and hydrodynamic pressure effects, respectively. The free vibration characteristics of the liquid storage tank are validated against experimental and theoretical results available in the literature.

Keywords

Free Vibration Buried Cylindrical Storage Tanks Finite Element Method Semi Analytical Procedure Conical Shell of Revolution Element Structure-Soil-Fluid Interaction Added Masses Viscous Dampers Elastic Half Space Model

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