Print ISSN: 1813-0526

Online ISSN: 2220-1270

About Journal

Al-Rafidain Engineering Journal (AREJ) is a global, scientific and open access journal. Publishing under the license of Creative Commons Attribution 4.0 International (CC-BY), The first issue of Al-Rafidain Engineering Journal (AREJ) was published in 1993 by the college of engineering – University of Mosul. The journal publishes Engineering Science articles at an average rate of two issues/year (Bi-annually). AREJ publishes original and valuable engineering research papers aiming at developing the knowledge in the fields of applied engineering science.  Al-Rafidain Engineering...
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Journal Information

Publisher: College of Engineering, University of Mosul


Editor-in-chief: Prof. Dr. Abdul-Rahim Ibrahim Al-Hadidy

Print ISSN: 1813-0526

Online ISSN: 2220-1270

Volume 28 (2023)
Issue 1
Volume 27 (2022)
Issue 2
Issue 1
Volume 26 (2021)
Issue 2
Issue 1
Volume 25 (2020)
Issue 2
Issue 1
Volume 24 (2019)
Issue 2
Issue 1

Volume 28, Issue 1, Winter and Spring 2023, Page 1-350

Consistency Relationship between Fractal Geometry and Adaptation as a Principle for Achieving Sustainable Architectural Design

Firas Hamdy Alsaffar; Khalid J. Aldeen Ismail; Shishin Mikhail Yurievich

Al-Rafidain Engineering Journal (AREJ), 2023, Volume 28, Issue 1, Pages 1-13
DOI: 10.33899/rengj.2022.134271.1182

This study deals with the concept of adaptation in natural systems, and the principles used by these systems to enable them to respond to changes and perform their functions within the processes of continuous growth. These principles include static and dynamic characteristics, which are used to match their sustainable characteristics in growth and adaptation. Here, the importance of fractal geometry emerged in explaining the complex nature with its formations and characteristics, as it is also able to grow and adapt continuously and interdependently. Thus, it helps designers achieve adaptation and growth in functionality and spatial requirements in the built environment through time, guided by sustainable natural systems.
The importance of adaptation emerges as one of the most important strategies for achieving an environment that is more capable of accepting the processes of modification and change, and thus accommodating changes and renewable spatial and functional requirements, and conforming to them over time. A building that is more adaptable is more efficient in being able to respond to changes. The benefits of achieving adaptation in architecture are represented in the efficient utilization of space, the increase in the life of the building and its compatibility with the changing requirements of the occupants in a better manner and at a relatively lower cost. This, in turn, leads to a reduction in relocation and abandonment of buildings and contributes to preserving the environment, by reducing demolition and construction operations, which result in damage as is well known. Adaptation is associated with a range of economic, social and environmental benefits, being one of the features of sustainable architecture. And since fractal geometry derives its structure and material and essential characteristics from nature, which is sustainable by default, it has in turn become an entry point for employing the characteristics of nature in architecture. The fractal structure's ability to grow and adapt has become echoed and reflected in the work of many architects. Through this, the two main axes of this study stand out. The first axis includes introducing the vocabulary of adaptation, its characteristics and requirements in architecture, and the second axis is related to proposing the equivalent principles of adaptation in nature, by using fractal geometry as a mechanism that can be used to explore and transfer these principles to architectural designs that contribute to achieving successful and sustainable construction.
The research discusses the hypothesis that adaptation can be a critical factor associated with sustainable architecture by using fractal geometry tools. This is done by discussing the proposals of many researchers and crystallizing their ideas to serve the goal of the research, which aims to achieve sustainable architectural design through the concepts of adaptation. The most important results of the research indicated that there is a harmonious relationship between the concepts of fractal geometry, including mechanisms dynamic growth, repetition within graduated scales, symmetry, and others, on the one hand, and between the concepts of sustainable nature with its adaptive characteristics towards various changes over time, on the other hand.

Off-Grid Photovoltaic System for a Villa at AVRO City in Duhok

Beren Sardar Abdullah; Siddeeq Y. Ameen

Al-Rafidain Engineering Journal (AREJ), 2023, Volume 28, Issue 1, Pages 14-23
DOI: 10.33899/rengj.2022.134729.1188

The off-grid solar photovoltaic system is one of the promising technologies for generating friendly electricity. Duhok city suffers from energy shortages in that electricity comes from local generators to support national grid. The aim of the research is to eliminate local generators due to their high costs and noise levels. A photovoltaic (PV) solar system type (off-grid) was proposed for one villa in AVRO city Duhok. A calculation has been done to select size of the system and A PV Syst software was adopted to investigate the design of the proposed system and additionally examined the economic analysis as well as the net profit. The proposed system is used with an average electricity demand of 12.9 kW/day. A typical 3.3 kW PV system was determined to be able to meet the daily power requirements of an entire villa with 8 panels: two in series and four in parallel where each panel has a rating of 415W. The system includes 8 batteries of 12 V,200Ah, and a 5-kW inverter with MPPT tracker. The result shows that yearly average of the energy requirement of villa is 4728.9 kWh and energy available through Solar’s panel is 5999 kWh/year

Interactive Reconstruction of Damaged Historic Landmarks – Al-Qattanin Mosque in Mosul Old City as a Case Study

Raghad Akram Abdulrahman; Emad Hani Al-Allaf

Al-Rafidain Engineering Journal (AREJ), 2023, Volume 28, Issue 1, Pages 24-35
DOI: 10.33899/rengj.2022.134720.1186

The use of technology in the field of urban heritage has increased in recent times due to the possibilities that   contribute to the management of conservation operations. The use of virtual reality systems is considered as one of the most important methods of digital preservation through the production of 3D models of historical buildings and then inserting them into interactive environments, such as the use of augmented reality systems, which allow the user to identify historical buildings through tablets and mobile devices to make them quickly and accessible. The research problem lies in the absence of studies on re-creating interactive models of historical buildings in Mosul old city. The current applied research aims to provide a working methodology to form an interactive model for a lost or damaged historical landmark through a methodology that works on collecting information sources on the damaged building and trying to rebuild it or recover the damaged parts of it by linking the information to produce a stereoscopic building , and then linking them to books and historical sources  .So that the user can identify it with a three-dimensional model that appears on the screen of the mobile phone or tablet after making a digital scan of the relevant book page and using the Unite AR application.

Integrative Conservation for the Reconstruction of the Historic Urban ‎Fabric: The Riverfront of Mosul Old City as a Case Study

Ammar Abdullah Hamad; Emad Hani Ismaeel

Al-Rafidain Engineering Journal (AREJ), 2023, Volume 28, Issue 1, Pages 36-48
DOI: 10.33899/rengj.2022.134593.1183

Due to the historical cumulative layers that were formed from the succession of construction, demolition, and sequential reconstruction, cities have become the essence of diversity, by evoking new urban forms that contribute to the creation and formulation of their urban heritage. Globally, redevelopment of the riverfront remains popular and is part of the urban planning agenda. However, this process is still often constrained by a set of strategic issues and difficulties in the cities of developing countries. The relationship between the urban fabric of the city of Mosul and its river frontage is a major criterion in evaluating the approaches and approaches to preserving the main features of the urban landscape of the city.
The current research aims to discuss the integrative preservation as a working methodology for a long-term plan based on previous global experiences and the basic guidelines approved by international laws to submit proposals for the reconstruction of the river front of ancient Mosul. It also aims to discuss the relationship between the historical urban fabric and the water environment and highlight the various methods that can be adopted to develop this essential part of the urban fabric of the city.
The research adopts the methodology of comparative analysis of conservation trends and intervention mechanisms, including integrative conservation, analysis of a number of relevant international studies, analysis of international conventions concerned with conservation, and obtaining qualitative data from a group of experts specialized in both aspects of urban preservation and urban renewal. This is in addition to obtaining quantitative data using the questionnaire method by designing a set of questions following Likert's Five-point Scale method and analyzing them using Microsoft Excel 2010, and applying them to the case study represented by the riverfront of the old city of Mosul.

The Effect of the Mechanisms of Directing the Recipient to Perceive Uniqueness on the Production of Unique Forms in the Urban Context -Mosul as a Case Study-

Shahad Nathim Sheet Rasool; Momtaz Hazim AL Dewachi

Al-Rafidain Engineering Journal (AREJ), 2023, Volume 28, Issue 1, Pages 49-63
DOI: 10.33899/rengj.2022.134726.1187

                   Architecture as a human production is considered as the principal source of distinguished elements within the city; such elements give the city its own identity. The progress of achieving such unique pieces is regarded as an urban design strategy which requires a particular methodology, depending not only on the designer but also on the perception of these elements. This paper concentrates on exploring the most important perceptual mechanisms that affect the recipient in making him distinguish the unique elements-particularly building- within an urban context. The study is spatially limited to the city of Mosul.
The problem of the current study is constituted in the lack of a comprehensive vision about the mechanisms affecting the direction of the recipient to realize the unique output, so that the designer can follow clear mechanisms to reach the realization of a unique building within its context.
This study aims to explore the mechanisms of guiding the recipient to realize uniqueness and the steps involved, within the different design practices, that affect obtaining a unique building. To achieve this goal, the research is defined by building the theoretical framework represented by the mechanisms of guiding the recipient to realize uniqueness, which includes two secondary axes: the first is the mechanisms of realizing uniqueness at the personal level of the recipient, and the second is the effectiveness of perceiving uniqueness at the level of urban structure.
The practical side of the study is conducted in two parts; The first is to nominate a number of unique local products based on the mental image of the users of that urban environment, and the second includes the application of the learned mechanisms to a number of unique local architectural products according to the mechanisms of guiding the recipient to realize the uniqueness.
The results show a great variation in the mechanisms that affect the realization of the unique building, which include the effectiveness of attracting attention, the element of surprise and mystery, the privacy of the building site, the available field of view and stimulation of the property of perception, and the size of the building in terms of distinguishing its height or size in its context, contrast with the background, through the type, color and properties of packaging materials that affect the realization of the unique building.
The study concluded that there is a significant role for the perception mechanisms followed by the recipient in achieving the uniqueness of the architectural production, as variables that contribute to the visual assessment of the output among users of the urban environment. These mechanisms vary in the extent of their impact on directing the perception of the recipient, in addition to the possibility of the influence of more than one mechanism in achieving the uniqueness of the same production within the urban context.

A Comparison of Assessment Systems for Sustainable Transport in the Urban Fabric: Standards and Requirements

Mahmood Khalid Al-A’abachi; Emad Hani AlAlaf

Al-Rafidain Engineering Journal (AREJ), 2023, Volume 28, Issue 1, Pages 64-73
DOI: 10.33899/rengj.2022.134761.1190

With the beginning of the twentieth century, the radical change of the fabric shape of the modern city  into    vertical  complexes, low-cost ‎individual buildings as well as the complet  separation of city functions by using private vehicles as ‎the main means of transportation,  result in  polluting its environment ,  and weakening its ‎urban identity. The current research aims to compare the global sustainable transportation assessments in order to reach the criteria and indicators which affect sustainable transportation and its requirements,  that, in turn, ‎affect the urban fabric and reduce the negative effects of the modern city. Through the analysis of the most reliable global systems ‎and  some of previous studies and projects, the research paper    identifies a set of standards for those systems with ‎regard to sustainable transport, which directly affect the shape of urban fabric, and which contribute to providing necessary ‎physical infrastructure for the effective functioning of sustainable transport systems within these communities.

Is Mosul University Campus Comfortable for Walking?

Rawia Marwan Dabdoob

Al-Rafidain Engineering Journal (AREJ), 2023, Volume 28, Issue 1, Pages 74-88
DOI: 10.33899/rengj.2023.136856.1213

Universities worldwide are essential institutions to upgrade society. Recently, the University of Mosul underwent certain circumstances after the 2003 and 2016 times of wars that varied among urban expansion, renovation, and rebuild some affected or demolished buildings, roads, walkways, and sidewalks. Hereupon, this research aims at measuring students´ comfort walking. This research contributes by advocating mobility network development on the main Campus. Six components involved with comfort walking were addressed namely: personal preferences, connectivity, accessibility, safety, convenience, and attractiveness. The study focused on the main Campus. Qualitative and quantitative approaches were adopted in data collection and analysis including observation, photography techniques, and questionnaire survey.
The sample of the study subjected the students who usually walk on the Campus. The findings reveal that the Campus generally gives the students a comfortable walking experience. Particularly, there is an agreement on connectivity aspects, moderate evaluation for accessibility aspects, agreement to some extent with safety aspects, moderate evaluation for convenience aspects, as well as attractiveness aspects. Besides, the findings indicate a requirement for further improvements especially in providing transportation services in the University for long distances, improving the physical elements, services, and facilities, which need more maintenance.

Using the Analytic Hierarchical Process in Determining the Relative Importance of some Spatial Criteria to Locate Railway Track

Aseel Ibrahim Matti; Ayman A. Abdulmawjoud

Al-Rafidain Engineering Journal (AREJ), 2023, Volume 28, Issue 1, Pages 89-98
DOI: 10.33899/rengj.2022.134691.1185

In this study, the weights of a number of criteria that affect the selection of the railway   track between   Mosul and   Fishkhabur on the Iraqi- Syrian- Turkish border are determined. These criteria include ground slope, water resources, irrigation canals, infrastructure services routes, land use, environmental impact, and soil bearing strength. A questionnaire is conducted for a group of decision makers, specialists and planners. The Analytic Hierarchical Process (AHP) technology developed by Saaty is implemented by using pairwise comparison among the criteria. This method is chosen due to its ease, accuracy and the existence of a specialized computer program to perform the mathematical calculations, incorporating weights for all forms, and extracting the final weight for choosing the path. The study shows that the water resources criterion of (29.7%) at a consensus rate of (57%) gets the highest relative importance followed by the ground slope criterion (21.3%) at a consensus of (49%).  The environmental impact criterion of (6.9%) at a consensus rate of (53%) gets the lowest value of the relative importance.

Reliability of Nondestructive Tests on Damage Assessment of Mosul Museum Building after Liberation Events

Saddam M. Ahmed

Al-Rafidain Engineering Journal (AREJ), 2023, Volume 28, Issue 1, Pages 99-108
DOI: 10.33899/rengj.2022.136409.1207

Nondestructive tests 'NDT' are increasingly becoming necessary tasks to develop accurate measurements without causing ‎‎any damage to the tested elements. The outcome of the NDT is vital to determining the safety and ‎‎reliability composition of materials. This study aims to investigate the dependability of nondestructive tests using Schmidt Hammer and Destructive Core Tests in a fire-damaged area. More than hundred stations were considered in the nondestructive inspection. Destructive core test results were used to assess the NDT results in burned concrete elements. The results of the comparison, clearly demonstrated the ability of both destructive and nondestructive ways to capture the strength reductions in fired elements. The NDT test provided an optimistic and higher strength prediction (higher 35-67%) as compared to destructive tests. Greater optimism NDT results were significantly associated with elements that have been highly damaged by fire and the strength predictions efficiency were between 60-67%. The results showed deviations in the mechanical properties of predicted burned concrete strength, by both on-destructive and nondestructive ways that required strength calibration to the nondestructive test to ensure more reliable assessment. A strength degradation formula is also suggested and is under review.

Laboratory Investigation on Rheological Characteristics of Asphalt Mastic with Waste Powder Materials from Mosic Tiles as Sustainable Filler

Abdulrhem Ibrahem Al-Hadidy; Mohammed Ghanim Jamel; Tan Yi-qiu; Dong Zejiao; Wang Jia-ni

Al-Rafidain Engineering Journal (AREJ), 2023, Volume 28, Issue 1, Pages 109-115
DOI: 10.33899/rengj.2023.138909.1241

To evaluate the possibility of using waste powder material (WPM) produced from moisc tiles polishing as a sustainble filler in asphalt mixture, some properties of asphalt mastic containing WPM were investigated in this paper, compared with the common limestone mineral (LSM) filler. The investigated mastic consisted of asphalt and filler at a mass ratio of 1:1. The rheological properties were tested using the penetration, softening point, ductility, elastic recovery, Furol viscosity, extensional viscosity, Dynamic Shear Rheometer, temperature susceptibility, compatibility, and Cone penetration tests. Results indicate the possibility of WPM as sustainble filler derived from mosaic tile polishing facilities to improve the performance of asphalt. The WPM has better effect on improving the shear, rutting and fatigue resistance as well as temperature sensitivity of asphalt mastic than LSM.

Improving the Efficiency of a Standard Distribution System Using the Correcting Power Factor Method

Muhammad A. Muhammad; Wael H. Hamdon

Al-Rafidain Engineering Journal (AREJ), 2023, Volume 28, Issue 1, Pages 116-124
DOI: 10.33899/rengj.2022.133666.1170

Most of the loads in the distribution system are inductive loads, due to the nature of household loads, most of which are reactive power consuming motors. These loads have a low power factor and cause voltage drop and increased power losses in the wires. The system most affected by power loss and voltage drop is the low-voltage distribution system of 0.4 kV, due to the large current that passes in this system.
In this research, a simulation of a standard low-voltage radial distribution system (IEEE 30 Bus System) was carried out in the Power World Simulator Program in order to evaluate and improve the efficiency of the distribution system by manually installing capacitors at each consumer to correct the power factor to reduce voltage drop and electrical power losses in wires. The system simulation was conducted at constant loads, and the ineffective power was compensated for by its equivalent manually, by adding capacitors to keep the power factor close to Unity.
The research aims to study the effect of power factor correction for each consumer on the overall distribution system efficiency, to be a basis for designing an automatic power factor correction unit that can be installed in homes, commercial buildings, and small factories. The simulation results were promising in terms of improving the overall system efficiency and reliability.

Mitigation of Total Harmonic Distortion and Power Factor Improvement Based PVSTATCOM

Ammar A. A. AL-Ani; Majid S. M. Al-Hafidh

Al-Rafidain Engineering Journal (AREJ), 2023, Volume 28, Issue 1, Pages 125-132
DOI: 10.33899/rengj.2022.134723.1189

The increasing use of power-electronics equipment has led to various power quality problems, including current wave distortion . Also, renewable energies (solar and wind energy ) are increasingly used to supply part of the electrical load,especially Photovoltaic (PV). The use of PV-STATCOM achieves many benefits, among them mitigating the distortion of the current wave , improving the power factor , compensatingthe active and reactive power , and improving the system 's stability. This paper deals with mitigating current wave distortion and improving power factors together. This paper designs a STATCOM Modular Multilevel Converter (MMC) controller with combines reactive power compensation and harmonicsmitigation for linear load and proposed a simulated six pulse three-phase rectifier as nonlinear load. The pulses gate of theswitches of the sub -modular converter has been obtained by using a proportional -integral (PI) current controller  with d-q references. The time-domain-based reference   method   for the reference current extraction is adopted. MMCSTATCOM were simulated with proposed nonlinear model loads in MATLAB . The simulation result showed  that the developed MMCSTATCOM minimizes the total harmonic distortion below the standards recommended by the IEEE.

Effect of Electric Vehicle Charging Stations on the Performance of Distance Relay

Wisam M. Najem; Omar Sharaf Al-Deen Al-Yozbaky; Shaker Mahmood Khudher

Al-Rafidain Engineering Journal (AREJ), 2023, Volume 28, Issue 1, Pages 133-144
DOI: 10.33899/rengj.2022.135233.1194

Distance protection is considered important and essential in power systems. Due to the development of distribution systems and the system's topology change from time to time, integrating electric vehicles into the distribution system leads to an increase in short circuit level and injection of harmonics into the system. Since the vehicles are continuously variable loads, this leads to difficulty in adjusting the protections that depend on the current in the process of adjusting them. As a result, distance protection is used in distribution systems. This paper shows the effect of integrating electric vehicle charging stations on the relay performance of distance protection in the distribution system. Distance protection relay was built based on artificial neural networks adapted to the system conditions. The accuracy of the neural network model used for fault detection was (99.9%), and the error rate in locating the fault was (0.00079%).

A Review of Miniaturized Advanced IC Rectenna for Energy Harvesting Applications

Shamil H. Hussein; Khalid K. Mohammed

Al-Rafidain Engineering Journal (AREJ), 2023, Volume 28, Issue 1, Pages 145-164
DOI: 10.33899/rengj.2022.135595.1198

This article presents a review of different types of miniaturized rectenna integrated circuits IC  used for energy harvesting applications such as medical applications. The rectenna design consists of two basic components: an embedded antenna that collects radio-frequency RF energy from the surrounding environment, and the rectifier circuit that converts AC-RF energy values into DC voltage for usage in low-power electronics devices such as implantable medical devices (IMDs). Microwave Schottky diodes HSMS-285x and SMS-763x series are used as a voltage doubler rectifier with an implanted antenna to improve conversion efficiency and the output voltage at a given input power and appropriate load. There are many challenges in the implantable rectenna IC design such as biocompatibility, miniaturization, patient safety, compact size, resonant frequency, bandwidth, radiation efficiency, and insensitivity to detuning. This review article summarizes the overall rectenna research carried out for new different design strategies in implant medical applications that operated at industrial scientific, and medical (ISM) bands such as 2.45GHz and 5.8GHz.

Using Solar Photovoltaic Systems, Battery Energy Storage Systems, and Underfrequency Load-Shedding to Improve the Frequency Stability of Power Systems

Suhib Fekry Hamid; Ahmed Nasser B. Alsammak; Khalid Tourkey Atta

Al-Rafidain Engineering Journal (AREJ), 2023, Volume 28, Issue 1, Pages 165-172
DOI: 10.33899/rengj.2022.136061.1201

Electrical power systems operate at 50 Hz. However, generation loss, a sudden increase in loads, or faults in the system cause disturbances and deviations that destabilize the frequency of electrical power systems. Therefore, there is a need to study and improve the frequency stability of electrical power systems during disturbances. The present study examines improving the frequency stability of electrical power system, using a solar photovoltaic (PV) system, a battery energy storage system (BESS), and underfrequency load-shedding (UFLS) to estimate and control the frequency.The proposed method was tested on a standard Institute of Electrical and Electronics Engineers' (IEEE®) 9-bus system that was simulated in MATLAB® Simulink. The simulation results indicate that the used method significantly stabilizes the frequency of electrical power system.

A Comparative Study of Total Harmonic Distortion betweenTwo Topologies 27- and 31 Multi Level Inverter

Muna Hassan Husien; Mohammed Ali A. Alrawe

Al-Rafidain Engineering Journal (AREJ), 2023, Volume 28, Issue 1, Pages 173-180
DOI: 10.33899/rengj.2022.134999.1192

In recent times,   Multilevel inverters are considered an essential component of power electronics with widespread use in a wide range of high-voltage and high-power industrial and commercial applications.  The use of multi-level inverters, also known as MLIs, has been preferred over conventional inverters due to the characteristics that these MLIs possess. These characteristics include low harmonic distortion caused by satisfacory performance of MLIs.  This paper is concerned with analyzing harmonics to gain a deeper understanding of the performance of cascaded H-Bridge multilevel inverters (CHB-MLI). The model was constructed by using MATLAB/SIMULINK. A comparison was made between an asymmetrical cascaded 27 and 31-level multi-level inverter (MLI) by using the Phase disposition sinusoidal Pulse Width Modulation (PD-SPWM)and Phase Opposition Disposition sinusoidal Pulse Width Modulation  (POD-SPWM) techniques. According to the outcomes of the simulations, 31 levels are better than 27 where Total Harmonic Distortion ( THD) in 31 levels is lower than 27 levels. The best result obtained during this study is  31 levels that use (PD-SPWM) technology, where the percentage of total harmonic distortion is small compared to the rest of the results and equal to 3.63%.

A Review on Power System Voltage Stability with Limitation of an On Load Tap Changing Transformer

Sinan M. Alkahdely; Ahmed Nasser B. Alsammak

Al-Rafidain Engineering Journal (AREJ), 2023, Volume 28, Issue 1, Pages 181-192
DOI: 10.33899/rengj.2022.136088.1202

Voltage stability of power systems reflects challenges to the power system operators due to its effect on the power systems components performances. Therefore, many solutions were invented in order to keep the systems within the voltage stability accepted limits. Because of the huge expansion of the power grids and the different loads natures on the grids, many techniques and solutions are used. The On Load Tap Changing Transformer (OLTC) was one of those techniques. In this paper, a review of past works that deal with the voltage stability limits, voltage stability improvement ways, OLTC types, the OLTC reverse action, and OLTC effect on voltage stability, in addition to several ways that make the OLTC work better. are discussed. The paper also sheds the light on the possible ways that may be employed to prevent the OLTC reverse action.  

The Effect of Reactive Power Capability of the Inverter on a Hybrid Power System

Raghad Adeeb Othman; Omar Sharaf Al-Deen Al-Yozbaky

Al-Rafidain Engineering Journal (AREJ), 2023, Volume 28, Issue 1, Pages 193-206
DOI: 10.33899/rengj.2022.136386.1206

Rising electricity consumption, rapid depletion of fossil fuels, and the global shift to the use of renewable energy resources have increased the need to integrate renewable and distributed energy resources (DERs), such as solar photovoltaic (PV) to power distribution networks. In this paper, the effect of photovoltaic system inverter scalability on reactive power compensation/absorption in a modified IEEE 13-node distribution network is studied. Power flow analyzes were conducted in MATLAB / SIMULINK software for different operating conditions to show the effect of reactive power on network voltage regulation, total harmonic distortion (THD) reduction, and power factor conservation in order to improve the system's power handling capacity. The result shows that the use of the PV system (500 kW) in Bus (671) led to a decrease in the generated power of the generator by 13.79%, the use of reactive power injection from the inverter of the photovoltaic system on site improved the voltage profile significantly. Also, the voltage distortion (THD-V) was reduced by 34% when injected with reactive power, and the current distortion (THD-I) was reduced by 57.65% when the reactive power was absorbed, and the power factor was improved on site.

A Review on D-STATCOM for Power Quality Enhancement

Ahmed Samir Alhattab; Ahmed Nasser B. Alsammak; Hasan A. Mohammed

Al-Rafidain Engineering Journal (AREJ), 2023, Volume 28, Issue 1, Pages 207-218
DOI: 10.33899/rengj.2022.136635.1210

Power quality problems in electric systems are one of the important topics that occupy a wide area of ​​interest to researchers and engineers. The increased use of power electronics circuits has led to improve efficiency and performance of the equipment; on the other hand, they withdraw a non-sinusoidal current and increase the harmonics which causes a decrease in the power quality. Also, these electronic devices are sensitive to power quality problems. However, advanced electronics can be employed to mitigate these problems. The Distribution static synchronous compensator (D-STATCOM) is one of the Custom Power Devices (CPDs) used for this purpose. D-STATCOM can be designed with different topologies, algorithms, and techniques of control to mitigate various power quality problems that face the power system. Selecting the D-STATCOM design depends on the power quality problem that needs to be mitigated. This paper presents a literature review of D-STATCOM from its beginnings to the present day.

The Impact of the Power Transformer Connections on the Flow of Zero Sequence Current

Mohammad Ahmed Ali Al juboori; Mohammed Ali A. Alrawe; Yousif Mohammed Younus

Al-Rafidain Engineering Journal (AREJ), 2023, Volume 28, Issue 1, Pages 219-229
DOI: 10.33899/rengj.2022.136263.1205

The effect of the various winding connections of three phase two windings transformer on the fault current at the line to ground (SLG-fault) and the double line to ground (DLG-fault) is studied. The ground faults are unbalanced  ; so, the analysis of these types of short circuit faults is divided into three balanced circuits which are known as symmetrical  networks. The zero sequence impedance appears in some types of transformer connections and its effect is reflected in the fault current value. This paper examines with help of MATLAB software by simulating a generating station and different transformer connections, the impact of three-phase two windings transformer connections   which occurs on a transformer secondary side to determine which the connections type of the transformer   gives the maximum and minimum zero sequence component of ground fault current.

The Influence of Temporal Logic on Finite Automata

Bilal Abdullateef Kareem; Ahmad Senjari

Al-Rafidain Engineering Journal (AREJ), 2023, Volume 28, Issue 1, Pages 230-238
DOI: 10.33899/rengj.2023.136476.1208

The  theory of automata combines ideas from engineering, linguistics, mathematics, philosophy, etc. The Entscheidungsproblem asks if it is possible to design a series of steps that replaces a mathematician. An automaton is an abstract machine that processes data. C. Shannon's theory is today's most popular despite having no relationship with the other. The Kt system is called "minimal" because it makes no assumptions about the structure of time. In LKt, we have four monary temporal operators, F, P, G and H, which are mutually interdefinable. Interdefinability means that we will pass logic in the future is the same as saying I will never fail logic,  interpreting not passing logic as failing logic. The minimal system syntax of temporal logic introduces operators that have the property of being defined in terms of others. Modal logic studies the reasoning that involves the use of expressions "necessarily" and "possibly". In this article, we will represent through a finite automaton the temporal logic formula Fp. It allows us to see an acceptance pattern for Fp by considering two variables: p and q. Kt's axiomatic system of time expresses the idea that both the present and the past are fixed, if it has always been in the past that it will be some time in the future that p is now. No philosophical argument supports deterministic time flow; the logic of time must be open.Temporal logic has revived many old problems, from the Megaric-Stoics to the minimal system of temporal logic. Our work suggests that the future operators of system Kt follow an evaluation pattern, but we must be cautious because this pattern can only apply to models whose time flow is based on instants and precedence relations.

The Effect of the Cooling Water Loop on the Exergy Destruction Components of Split Air Conditioning Systems

Diyar Abdullah Ahmed; Omar Mohammad Ali

Al-Rafidain Engineering Journal (AREJ), 2023, Volume 28, Issue 1, Pages 239-248
DOI: 10.33899/rengj.2022.135328.1195

The present study is an experimental investigation to improve the performance of the air conditioning unit (ACU) by precooling the condenser with a cooling water loop using a water heat exchanger with the employment of energy and exergy analyses under various ambient temperatures between 30 – 45°C at different inlet water temperatures; 15, 19, 24 and 30°C and water flowrates; 9, 11, 14 and 15.8 L/min. The results indicated that the cooling water loop have a large effect on the exergy destructions as compared with those of the no water case. When a cooling water loop is used, the compressor, evaporator, and expansion valve irreversibilities reduced. The exergy efficiency of the unit decreases as Tamb increases to about 23%; while, the exergy efficiency increases when cooling water loop is used depending on the inlet water temperature and water flowrates. The maximum enhancement in the exergy efficiency is obtained at high water flowrate for Twi = 15°C with a percentage value about 13% as compared with those of the conventional ACU.

Investigation of Thermal Performance of Integrated Phase Change Materials in Building Structure

Shwan O. Salih; Rizgar Bakr Weli; Abdulkader Ali Abdulkader

Al-Rafidain Engineering Journal (AREJ), 2023, Volume 28, Issue 1, Pages 249-255
DOI: 10.33899/rengj.2022.135073.1193

About 40% of the world's primary energy is used by buildings. This indicates that the bulk of greenhouse gas emissions are caused by buildings. In this investigation, the decrement factor (DF) and time lag (TL) of a new 3D-printed model are experimentally determined. It is really time to cut back on such energy consumption to lessen buildings' negative environmental effects. The introduction of new model 3D-printing blocks with high thermal inertia might be a way to lower the building's energy usage. Decrement factors and time lag are characteristics of thermal inertia. In this investigation, the decrement factor and time lag of a new 3D-printed model are experimentally determined. At the University of Salahadin's College of Engineering, a pilot house measuring 1 m x 0.45 m x 0.45 m is constructed specifically for this application. The equivalent temperatures of the inside (room one) and outside (room two) are used to determine the decrement factor and time lag. The findings indicate that using the new 3D-block model, the time lag is around 120 minutes, and the decrement factor is approximately 0.34. The 3D-printing block enables a 4.5°C reduction in the peak interior temperature. Since temperature changes outside are not noticeable, less energy is used to cool the structure during warm weather.

The Experimental Investigation of Double -Pass Solar Air Heater with V-Corrugated Plate, Phase -Change Material and Baffles Under Recycling Operation

Omar Mohammad Hamdoon; Ibrahim Ababakr Ali

Al-Rafidain Engineering Journal (AREJ), 2023, Volume 28, Issue 1, Pages 256-271
DOI: 10.33899/rengj.2022.136090.1203

The current paper presents an experimental work that had been implemented to observe the performance of an improved solar air heater and compared it with that of a conventional double-pass flat plate solar air heater. Improvements that have been added include the use of a V-shaped corrugated plate at an angle of 60 degrees, the addition of wood baffles in the lower pass and the use of phase-changing materials PCM as well as air recycling conditions. The heater was designed and tested under the weather conditions prevailing in the Duhok Governorate (latitude 36° 52' 1.52" N and longitude 42° 59' 18.42" E) in the Kurdistan Region of Iraq. The phase-changing material PCM is paraffin wax. The gathered results showed that the improvements that were added to the solar air heater significantly improved the performance at different mass flow values (0.037, 0.057, 0.077 kg/sec). For example, the maximum values of useful heat transfer at mass flow rates (0.037, 0.057, and 0.077kg/s) are 1.68, 1.86, and 2.34 kW, respectively, and   the daily efficiency for improving and conventional heater value at mass flow rate 0.037kg/s for 15,16, and 17 of February on 2022 was (84% and 45%), (86% and 46%), and (91% and 60%), respectively.

An Experimental Comparison Between Fixed and Single-Axis Tracking Photovoltaic Solar Panel Performance: Zakho City as Case Study

Veen Sagvan Qader; Omar Mohammed Ali; Nawfal Idrees Hasan

Al-Rafidain Engineering Journal (AREJ), 2023, Volume 28, Issue 1, Pages 272-279
DOI: 10.33899/rengj.2022.136292.1204

The tracking system that uses for PV solar systems has a vital role to improve the energy performance of the solar panel. In the present study, the performance of both the fixed PV solar system and single – axis tracking PV solar system is investigated experimentally. The power for each PV solar panel is 150 W. The performances of the two systems are compared to display the efficient improvement of a single-axis solar tracking (SAST) system with fixed solar (FS) system under the climate conditions in the Zakho/ Kurdistan region/ Iraq. A mechanical tracking device with a controller and linear actuator was designed, and its performance was comprehensively investigated with a PV system. The findings for a sunny day due to the use of a single axis tracking system with a solar panel as compared with those of a fixed panel, that the enhancement in the overall power generation and electrical efficiency are about 28 % and 29 %, respectively.

The Experimental Impact of Convective Heat Transfer Improvement from Numerous Perforated Shape Fin Array

Noori Raad Noori; Arkan Fawzi Saeed

Al-Rafidain Engineering Journal (AREJ), 2023, Volume 28, Issue 1, Pages 280-292
DOI: 10.33899/rengj.2022.136544.1209

The current work explores a trial forced convective heat move from rectangular blades on an upward surface at low Reynolds numbers. The heat removal for a proper number of punctured and non-punctured fins, fin dividing, and length was estimated in an upward air stream for fluctuating inlet air speed and some way or another low info heat power somewhere in the range of 20W and 70W. The characteristics are investigated for rectangular, circular, and V-shape perforated fin array against non-perforated one. The impact of different boundaries, like heat input with various liquid stream speed on average coefficient of heat transfer (h) improvement has been considered. The impact of the Nusselt numberand Reynolds number, were practically examined. The heat loss has been improved by increasing the heat transfer coefficient between the fin total surface and its encompassing, through increasing the area of heat to remove all out surface through fin perforations. The trial relations have been differentiated by correlating Nu and Re for non-punctured plate heat sink, the reach 6*103 £ Re £ 19*103, and Pr @ 0.7 with error ±7%, and punctured finned plate heat sink with the reach 6*103 £ Re £ 20*103, and Pr @ 0.7 with a deviation factor R2=0.995.

Heat Transfer Analysis of the Melting Process on Finned Tubes (A Review on performance enhancement)

Noor Jamal Younis; Omar Mohammad Hamdoon; Ziad Mohammed Majeed; Mohamad Kharseh

Al-Rafidain Engineering Journal (AREJ), 2023, Volume 28, Issue 1, Pages 293-299
DOI: 10.33899/rengj.2023.137167.1215

The performance of thermal systems, like heating and cooling systems, depends on a number of factors such as the geometrical shape, the working fluid used to transfer or store heat, and the operating conditions. Accordingly, many studies concentrated on improving the thermal performance of such systems and raising their thermal efficiency by modifying their geometry or using phase-changing materials. Therefore, this work is reviewing the previous studies that dealt with modifying the geometry, by adding annular or longitudinal fins on the main tube of the heat exchanger, and employing different types of phase change materials. This article also presents the previous scientific articles that investigated the effects of changing the location and the orientation of the fins. For the reviewed studies in this article, it is worth mentioning that the numerical investigations outnumbered the experimental ones as the authors focused on finding the optimal design of the studied thermal systems. Furthermore, the previous studies employed phase-change materials, e.g. fatty acids, waxes, and salts, due to their ability to store energy and reuse it in a wide range of applications.

A Review of Issues and Challenges to Address the Problem of Implementing Green Computing for Sustainability

Turkan Ahmed Khaleel; Jumana Abdullah kareem

Al-Rafidain Engineering Journal (AREJ), 2023, Volume 28, Issue 1, Pages 300-311
DOI: 10.33899/rengj.2022.135485.1197

In a larger sense, "green computing" refers to strategies and procedures for creating, utilizing, and disposing of computer resources in three ways: maintaining total computing performance, minimizing the impact on the environment, and maintaining overall computing performance. This entails using less dangerous materials, getting the most usage possible out of a product while using the least amount of energy possible, as well as making old items and the garbage more reusable, recyclable, and biodegradable. Many businesses are making efforts to lessen the negative effects of activities on the environment. The framework Convention on Climate Change of the United Nations (UNFCC)is a global environmental agreement whose goal is to keep greenhouse gas emissions stable to a degree that would prevent adverse anthropogenic interference with the environment. Sustainable development entails growth that doesn't jeopardize the needs of coming generations. That is achieving human development goals while protecting the ecosystems and natural resources that are essential to civilization. The relevance of green computing for sustainable development is emphasized in this paper's assessment of many significant recent studies on the subject.

Securing Industrial Internet of Things (Industrial IoT)- A Reviewof Challenges and Solutions

Mohammed Basil Mahmood; Jassim Mohammed Abdul-Jabbar

Al-Rafidain Engineering Journal (AREJ), 2023, Volume 28, Issue 1, Pages 312-320
DOI: 10.33899/rengj.2022.135292.1196

Industrial IoT (Industrial IoT) is a new promising technology which can be used to increase the amount of productions with high qualities. Industrial IoT technologies guarantee full control to the processes remotely through the internet which can reduce the number of workers in the field. As a result, this can reduce the percentage of worker injuries and accidents in addition to the total costs. The Industrial IoT systems are attractive targets to attackers. For this reason, these systems require high levels of security since such levels have direct effects on physical devices which may be dangerous on human life and safety. To   guarantee high level of security, a combination between Information Technologies (IT) and Operation Technologies (OT) with new innovative methods should take place. In this paper, many new technologies and security methods are reviewed with their possible attacks in order to provide Industrial IoT infrastructure designers with the required information to take them into consideration. Also, differences and convergences between both classical Information Technology (IT) and operational Technology (OT) and their relations to the Industrial IoT systems are investigated with the possible attacks on each layer of the IT and the OT.

A Computer Simulation of a Modified Oldham Coupling

Ahmad Wadollah Al-Sabawi

Al-Rafidain Engineering Journal (AREJ), 2023, Volume 28, Issue 1, Pages 321-328
DOI: 10.33899/rengj.2022.135806.1199

In this research, an Oldham coupling is used, and it has been modified to obtain new features. The modification is made on the intermediate part of the Oldham coupling and hence a kinematic model is approached, and two new applications are found. The proposed mechanism can be used as a function generator for some specific functions such as cardioid for the ratio, crank/shift=1, and the second finding as a sort of quick return mechanism. The results of the mathematical model show a good agreement with those of the cad model simulation and the related literature.

An Efficient Security Model for Industrial Internet of Things (IIoT) System Based on Machine Learning Principles

Sahar L. Qaddoori; Qutaiba Ibrahim Ali

Al-Rafidain Engineering Journal (AREJ), 2023, Volume 28, Issue 1, Pages 329-340
DOI: 10.33899/rengj.2022.134932.1191

This paper presents a security paradigm for edge devices to defend against various internal and external threats. The first section of the manuscript proposes employing machine learning models to identify MQTT-based (Message Queue Telemetry Transport) attacks using the Intrusion Detection and Prevention System (IDPS) for edge nodes. Because the Machine Learning (ML) model cannot be trained directly on low-performance platforms (such as edge devices),a new methodology for updating ML models is proposed to provide a tradeoff between the model performance and the computational complexity. The proposed methodology involves training the model on a high-performance computing platform and then installing the trained model as a detection engine on low-performance platforms (such as the edge node of the edge layer) to identify new attacks. Multiple security techniques have been employed in the second half of the manuscript to verify that the exchanged trained model and the exchanged data files are valid and undiscoverable (information authenticity and privacy) and that the source (such as a fog node or edge device) is indeed what it it claimed to be (source authentication and message integrity). Finally, the proposed security paradigm is found to be effective against various internal and external threats and can be applied to a low-cost single-board computer (SBC).

A Review on Fog Computing: Research Challenges and Future Directions

Omar Anwer Nafea Alani; Turkan Ahmed Khaleel; Othman H. Al-Abdulqader

Al-Rafidain Engineering Journal (AREJ), 2023, Volume 28, Issue 1, Pages 341-350
DOI: 10.33899/rengj.2022.136642.1211

The traditional centralized cloud computing paradigm confronts several problems, including a lack of capacity, high latency, and network failure, due to the rapid expansion of IoT (Internet of Things) applications. Fog Computing brings cloud computing and IoT devices closer to addressing these issues. Instead of transferring IoT data to the cloud, the Fog allows local processing and storage of IoT data in IoT devices. Fog Computing offers services with a quicker response time and higher quality than the cloud. Therefore, Fog Computing may be considered the greatest option for enabling the IoT to provide efficient and secure services to many IoT users. In this paper, we define the term "Fog Computing," examine its architecture  and list its features. We also talk about other related work and emphasize it.

Keyword Cloud