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

Email:  drjssm@uomosul.edu.iq

Editor-in-chief: Prof. Dr. Jassim M. Abdul-Jabbar

Print ISSN: 1813-0526

Online ISSN: 2220-1270

Parametric Customization of Single-Family Housing Designs Ain Al-Iraq Housing Complex as a Case Study

Doaa Mosab Attarbashi; Dhuha Abdulgani Al-kazzaz

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 2, Pages 1-17
DOI: 10.33899/rengj.2021.129519.1083

The advent of digital architecture, including parametric design, enabled the customization in housing design. The parametric typological design allowed diversity, difference, and individuality with the same ease of mass- standardized production. Accordingly, the paper investigated the customization of housing components to satisfy the customer's options and in response to different local conditions. The research problem was the application of customization in parametric typological design to generate prototypes for single-family houses of Ain Al Iraq project in Mosul city. The research aims were to identify the customization methodology and to apply it in a case study. The previous studies put forward different approaches combining generative systems controlled by a set of parameters, constraints and rules developed by the designer, and the interactive customized systems that allow customers to participate in the design process. In the light of these studies, the paper presented a theoretical framework to define the methodology of applying the customization in the parametric typological design process using four vocabularies to identify the types of customization, the methods of standardization, and the roles of a designer and a customer. In the practical study, the approach was applied to create a parametric model using (Grasshopper) software, in order to generate initial plans for single-family houses that were customized according to the customer's need. The user interface was also designed by the researchers to provide direct interaction and ease of use by regular customers. The results showed the generation of initial plans having varied parameters according to the customer's options.

Interactive Design in Urban Outdoor Spaces A Comparative Study of the Employment of Digital and Traditional Technologies

Suha Imad Aldobouni; Ahmed Y. Alomary

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 2, Pages 18-31
DOI: 10.33899/rengj.2021.129352.1080

Interactive design is a modern design approach that have gained a clear interest in the field of outdoor spaces. It depends on increasing elements of suspense, pleasure, learning, changing behavior and enriching the users' sensory experience and interaction through the five senses, to achieve an enjoyable experience and a good function that is easy to use. The research problem represented by the existence of traditional, passive and inactive urban spaces intended by few urban users. The research aims to explore employing digital technologies, formulas and methods of generating them for the purpose of applying them in external spaces, trying to revive urban outer spaces in contemporary cities. In this study, many examples of projects designed and implemented for external spaces that employ digital and traditional technologies have been analyzed and compared with each other, based on interaction criteria extracted from previous studies. Through the application of statistical tests, the results indicated that designs based on digital technologies generate relatively more interaction than those that rely on traditional techniques. The results indicated that optical technology is the most widely used technique in interactive outdoor spaces. The most effective interactive technologies on the recipient work through stimulating interest and curiosity.

The Design Characteristics of the Architectural Elements in the Houses of the Old Mosul City -An Analytical Study of the Iwan Element -

Sinan Mohammad Talee; Anwar Meshal Shareef

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 2, Pages 32-53
DOI: 10.33899/rengj.2021.129310.1079

Traditional architecture is characterized by specific configurations and elements, possessing design characteristics (formal and functional) that give the products of traditional architecture their character, As in the traditional architecture of the old city of Mosul. The buildings of the old Mosul city, have been subjected to damage as a result of the recent terrorist events, it was necessary to document and study these buildings by isolating the basic design elements that make up the building and studying its properties in a detailed method. The presentation of previous studies that dealt with the Mosul architecture revealed that there is a lack of knowledge specifically the Iwan element and its design characteristics, which determined (the nature of the research problem) while (the goal of the research) to discover the design characteristics (formal and functional) of the iwan in the architecture of old Mosul houses and extract the most important characteristics prevailing in it. The research Methodology builds on the structure of a theoretical framework that includes the definition of the architectural element and its design characteristics in general, and the definition of the iwan and its characteristics in the architecture of Mosul in particular. The analytical study of the Iwan was performed by two levels, depending on the database and images that were obtained and documented:The first (general level): This level included collecting and documenting various pictures of ‎‎24random samples from Iwans of the Mosul houses, and‎‏ ‏application of an analytical and descriptive study to discover their design characteristics.The second (detailed level): This level included collecting and documenting some pictures, information, and detailed drawings of 10 samples (For the element iwan predominant – pointed-), which were analyzed mathematically to reveal their proportions, and graphically using the AutoCAD program to reveal their detailed formal characteristics to reach a more accurate database that can be invested in restoring Construction of the old city.

Pre-Fabrication of Marble Window Frames In Mosul's Traditional Houses / An Analytical Documentary Study of its Repeated Models

Abeer Khaleel Al_alaf; Ahmed Abdulwahid Dhannoon

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 2, Pages 54-74
DOI: 10.33899/rengj.2021.129742.1086

The heritage city of Mosul was distinguished by the architectural and technical characteristics that distinguished it from the rest of the Islamic cities, which were affected by the surrounding environment and the quality of the natural materials available locally, the most important of which was the material of Mosul marble (alfarsh) on the one hand, and the techniques used in its manufacture on the other hand, , Which gave special features and characteristics of the Mosul's architecture.  In the beginning, previous studies related to the subject were reviewed to determine the research problem, which was represented by (lack of knowledge related to the technology of manufacturing marble window frames in Mosul's houses).
Consequently, the goal of the research was to reveal the manufacturing technology and characteristics of this important element in the traditional Mosul's house in detail by scanning its repeated models to provide a complete database that can be used in the future in the reconstruction operations. The research adopted the analytical documentary survey method for this element by extracting basic vocabulary for them from previous studies and then applying these terms in selected samples, and then drawing this element with all types and models with dimensions and detailed measurements in the AutoCAD program (2016) to be analyzed after that according to the vocabulary of the theoretical framework, reaching to the final conclusions that showed the similarity and repetition of the models for this element in terms of dimensions and number of pieces, and that this element was governed by specific models, fixed measurements, and specific installation and formation methods with some exceptions, which reinforced the assumption made by the research that this element is per-manufactured.

Pre-Fabrication of Alabaster Columns in Mosul's Traditional Houses /An Analytical Documentary Study of its Repeated Models

Abeer Khaleel Al_alaf; Ahmed Abdulwahid Dhannoon

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 2, Pages 75-95
DOI: 10.33899/rengj.2021.130023.1092

The traditional alabaster columns with manufacturing techniques used by Mosul's architects represent one of the aspects of distinction within the heritage Mosul architecture, which gave this architecture aspects of its peculiarity and distinctive identity. After reviewing previous studies in this field, the research problem was represented by (Lack of knowledge related to the manufacturing technology and characteristics of alabaster columns in Mosul's traditional houses and lack of knowledge of their repeated models and details of their employment) The aim of the research was (revealing the techniques of manufacturing these elements as well as clarifying and analyzing its repeated models and clarify the details of the employment of each model) and thus providing a detailed documentary information base that can be adopted in the operations of restoration, reconstruction, and future designs. The final conclusions that showed the similarity and repetition of the models for this element in terms of dimensions and number of pieces, and that this element was governed by specific models. Each type has fixed measurements and specific installation and formation methods with some exceptions, which reinforced the assumption made by the research that this element is a prefabricated element.  

Existing and Future Traffic Congestion Reduction Study in Mosul Left Coast Using an Electronic Algorithm

Mohannad R.M. Askar; Abdulkhalik M. Al-Taei

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 2, Pages 96-103
DOI: 10.33899/rengj.2021.128135.1060

Traffic mapping is the fourth, final, and very important step of the urban transport planning process.the algorithm that was developed using several programs. Such as the Geographic Information Systems (GIS) program, the Digextra algorithm, the Python program, in addition to the (SIDRA-8-2018) program, which is a program specialized in engineering work for methods to determine the shortest path within the selected network during the present time in addition to future strategic periods.Three future periods have been determined to test the road network load with traffic volumes, determine the locations of defects that will occur now and, in the future, and try to find solutions and alternatives that ensure the flow of traffic within this network. Each strategy period included the growth of traffic demand for a period of five years, starting from 2020 until the target year 2025. During these five years, traffic demand is supposed to increase by 6% annually. The results obtained from this study were represented by different plans to address the traffic problems that occur in the different areas of the road network. Those areas were identified and different scenarios and solutions would be required to regulate the traffic for the strategic periods.

Parking Study at University of Mosul Main Campus

Dr. Mohammed Yasseen Taha; Hadeel Hussein Ali

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 2, Pages 104-117
DOI: 10.33899/rengj.2021.129006.1074

During the last years, the Main Campus of Mosul University's growth has meant increased traffic volumes (vehicles and pedestrians flows) on its streets, with longer wait times at the campus gates, and parking problems. The main objective of this work is to describing, measuring and valuing the current condition of parking supply and demand, and recommending the most suitable solutions to parking problems according to the university needs for the future 10 years. The study area is divided into 21 zones. Field surveys include: parking survey, questionnaire survey, and traffic movements survey were conducted to achieve the study objectives.   The results show that the largest percentage of faculty members and staff use their vehicles as a motorist, especially males with more than 64% for faculty and 55% for staff. The dominant mode of travel for the female faculty members and staff is passengers (Auto and transit) with 60.25% and 82.1% respectively There are over 4181 available parking spaces distributed among the study area zones. Additional parking spaces will be provided where possible and a combination of parking structures and surface lots must be resized and located to meet the parking demand for the year 2030.

Beam Tracking Channel for Millimeter-Wave Communication System Using Least Mean Square Algorithm

Ban A. Asi; Farhad E. Mohmood

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 2, Pages 118-123
DOI: 10.33899/rengj.2021.129143.1076

Millimeter-wave (mmwave)is an attractive option for high data rate applications in the 5G wireless communication that requires proper beamforming, channel tracking, and channel change. Adaptive beams are formed by relying on adaptive algorithms. In this paper, we study, analyze, and compare the performance of the least mean square algorithm (LMS) and normalized least mean square (NLMS) for tracking channel status and transmit array beam. When using LMS algorithms and natural NLMS algorithms, an adaptive filter usually results in a trade-off between convergence velocity and adaptive accuracy. The results showed that the LMS algorithm is one of the simplest types of algorithm but it needs a large step size to obtain faster system convergence and stability. NLMS algorithm is a special application for the LMS algorithm, in which NLMS algorithm takes into account the change in the signal level when applying the filter and specifies the normal step size parameter μ. this leads to stability as well as rapid convergent adaptation of the algorithm. 

Reactive Power Control using STATCOM for Power System Voltage Improvement

Sabah Abdulkareem Yousif; Saad Enad Mohammed

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 2, Pages 124-131
DOI: 10.33899/rengj.2021.128914.1070

Stability of power system is the ability of the system, with a certain initial operation conditions, to restore the operating balance conditions after exposure to disturbance such as faults or sudden load changes. More attention is required to address voltage instability problems to keep voltage profile under control during abnormal conditions. This paper proposes a Static Synchronous Compensator (STATCOM) using (MATLAB / Simulink Program) The STATCOM includes proportional-integral (PI) control model is used to control the voltage during abnormal conditions by absorbing or injecting reactive power into the power system. Simple and reliable PI controller has been used and designed to be stable under various operating conditions. Three phase Two level PWM strategy technic used in STATCOM controller to decrease the harmonics injected after adding STATCOM to the power system (THD = 2.21%). The simulation study has been done by using 9 buses IEEE system after making a disturbance such as sudden load change. Then the voltage profile during this interval is being studied with and without using STATCOM. The simulation results show that adding STATCOM to this system led to improve the voltage profile during disturbance interval and made the system more stable and reliable by preventing the disturbance effects from reaching the generation side (Vbus 5 = 0.8980 pu, during disturbance before adding STATCOM, Vbus 5 = 1.0003 pu, during disturbance after adding STATCOM). The fast response of the STATCOM controller gives the ability of injecting or absorbing reactive power during disturbances and keeping the system voltages within the IEEE standards limits (0.95 pu > V> 1.05 pu).

Output-Input Hybrid Passive Filter Design for Electric Vehicle Charging Station

Shaker Mahmood Khudher; Ishak bin Aris; Mohammad Othman; Nashiren Mailah

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 2, Pages 132-142
DOI: 10.33899/rengj.2021.129599.1084

The impact of electric car charging stations on power grid harmonics is growing as their existence continues to expand and creates harmonic distortion in the power system. At the same time, the quality of charging current and voltage through the process of charge becomes inferior. Therefore, reduction of output ripple factor (RF) and mitigation of input current harmonics is vital in this situation. This paper presents the design of the output filter and three kinds of shunt passive input filters to decrease the present harmonics generated in the industrial power scheme by the charging stations. The simulation software MATLAB/Simulink was used. Results were acquired before and after installation of filters and after installation of filters, it was found thatthe percentage RF of output current, voltage, and the percentage THD of the input current is reduced to match the set standards.

Three Component Weather-Sensitive Load Forecast using Artificial Neural Network

Yamama Anwar Al-Nasiri; Majid S. M. Al-Hafidh

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 2, Pages 143-149
DOI: 10.33899/rengj.2021.130019.1091

The electrical load is affected by the weather conditions in many countries as well as in Iraq. The weather-sensitive electrical load is, usually, divided into two components, a weather-sensitive component and a weather-insensitive component (baseload). The impact of the weather-sensitive component includes the summer and winter periods, without distinguishing between them. The characteristics and specifications of this component differ in summer and winter due to the different loads in the seasons, so it is best to separate these two components into two independent components. The research provides a method for separating the weather-sensitive electrical load into three components, the summer component, the winter component, and the base component. The artificial neural network was used to predict the weather-sensitive electrical load using the MATLAB R17a software. Weather data and loads were used for one year for Mosul City. The performance of the artificial neural network was evaluated using the squared error rate and the mean absolute error ratio. The results indicate the accuracy of the prediction model used in the research.

A Novel Method to Manage the Electrical Energy Profile in Iraq: Virtual Power Plant (VPP)

Ahmad Ali Khalaf; Omar Sh. Al-Yozbaky

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 2, Pages 150-157
DOI: 10.33899/rengj.2021.130044.1093

A virtual power plant (VPP) is considered a combination of distributed generation connected with energy storage devices and interruptible loads. This system is controlled as a single flexible unit in the electricity market and in the main grid. Due to numerous problems in the main grid such as variation of frequency and the Interruption in power supply as a result of the peak load. As well as economic and material constraints, Considered the optimization solution for scheduling resources and overcome for these problems is VPP. This study proposed different scenarios for two-sector of homes in Iraq which simulated in Matlab Simulink software. The method is implemented on a test system with a VPP comprising a distribution generator, energy storage devices, and loads. The economic characteristics of these resources and of the network were calculated. the results showed a decrease in the bill of electricity for these homes by 50%. Simulation results display a benefit from the use of VPP when compared to DG based only on renewable interrupted generation.

The Impact of Length of Frame on The Performance of Video Application in WiMAX System

Mohammed Younis Thanoun

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 2, Pages 158-163
DOI: 10.33899/rengj.2021.130685.1121

The IEEE 802.16e standard includes several features that aid data capacity. When dealing with real-time applications such as video conference services, however, it quickly depletes its resources. The quality of the video, on the other hand, is a crucial factor for the user. There is a tradeoff between the video quality and the resources available. In this paper the influence of frame length on video applications was investigated by examining the effect of four frame lengths (5, 10, 15, and 20 mSec) on the Packet Delay Variation, End-to-end packet delay, traffic sent and received with modulation type 64QAM and high quality of video conference application are used. The optimal frame length was found to be 10 milliseconds, with the Packet Delay Variation being the smallest, the Packet End-to-End Delay being the shortest, and the number of received packets being equal to the number of sent packets.

Study of the Impact of Antenna Selection Algorithms of Massive MIMO on Capacity and Energy Efficiency In 5G Communication Systems

Sawsan N. Abdullah; Farhad E. Mohmood; Yessar Ezzaldeen Mohammed Ali

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 2, Pages 164-170
DOI: 10.33899/rengj.2021.130499.1110

Massive MIMO system in the fifth generation can consume a large amount of energy. In this research, the selection of antennas was studied based on several algorithms and a new algorithm was proposed for the selection of antennas. The results showed through a comparison between the approved and proposed methods in the research in terms of capacitance that The proposed algorithm is the closest in terms of capacity to the ideal case, as this method is considered almost ideal for its application in multi-input and multi-output systems to improve performance in the fifth generation, followed by the greedy algorithm and algorithm norm, as it was noted from During the comparison in terms of energy efficiency, it is possible to increase energy efficiency when choosing a certain number of antennas

Simulation of High Efficiency Tandem Solar Cell using InGaP/GaAs

Marwah M. Salim; Khalid Kh. Mohammed

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 2, Pages 171-178
DOI: 10.33899/rengj.2021.130603.1114

The dual junction (tandem) cell structure (InGaP/GaAs) is depending on Indium gallium Phosphides (InGaP) as the upper cell, Gallium Arsenide (GaAs) as the lower cell, and behaves as tunnel junction (TJ). The structure of the (InGaP/GaAs) dual junction cell was simulated in this work using SILVACO program to obtain a high solar cell efficiency.  Firstly, the effect of doping concentration and thickness of window layer of the upper cell was investigated on the (InGaP/GaAs) tandem cell performance. Then the GaAs /GaAs (TJ) is replaced by an InGaP/GaAs (TJ).A comparison of performance parameters between the two types of tunnel diode (GaAs / GaAs) and (InGaP/GaAs) was studied. The parameters that have been compared are open-circuit voltage (VOC), efficiency (η), the short circuit current density (JSC), and Fill Factor (FF). Quite high operating factors for tandem cell are achieved by taking into account the crucial number of cells as well as improving layer parameters of the layers. All calculations and simulations of tandem cell are performed with the typical AM1.5 solar spectrum light intensity of 1-sun at room temperature (300 K). Lastly, the findings illustrate that the optimum properties of the suggested tandem cell are efficiency (η) = 34.37 percent, VOC = 2.449 V, JSC = 21.69 mA/cm2, FF=89.33 percent.

Studying the Effect of Adding the Concrete Reinforcement Grid Rods to the Grounding System of the Mosul Secondary University Distribution Station

Saleh k. Ahmad Algehiche; Riyadh Zaki Sabry

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 2, Pages 179-186
DOI: 10.33899/rengj.2021.130845.1122

In this research, a study was conducted to re-evaluate the safety levels of the grounding system for the Mosul Secondary University distribution station, by taking the effect of the conductors of the foundation arming grid on the electrical potential distribution resulting from faults to the grounding system implemented by the Lebanese company (MATELEC s.a.l). A fault current of (20kA) was adopted. The CYMGRD program was used to re-design the grounding system implemented by the company in two stages, first without taking the effect of the arming grid of the foundations, and then the grounding system was redesigned by adding the arming grid of the foundations implemented inside the concrete and linking it with the basic grounding system that was formed of conductors and grounding rods, and the results showed the significant effect of the foundation arming grid in reducing the levels of touch voltage (Em) by 33%.

An Experimental Study to Verify the Thermal Performance of a Solar Air Heater Used for Space Heating and Ventilation

Mohammed Ali Mohammed Saleh; Omar Mohammed Hamdoon

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 2, Pages 187-200
DOI: 10.33899/rengj.2020.129055.1073

This study included an experimental analysis for the purpose of improving the performance of a conventional double-pass solar air heater by replacing the flat absorber plate of the conventional model with a corrugated plate and adding steel wool in the lower passage of the air heater while keeping all dimensions constant for the two models. The two systems were operated together under the same conditions and at a constant airflow (0.0416 kg/s). The results showed that the thermal efficiency and the temperature of the air exiting from the solar heater can be improved using the improvements that have been indicated, as the highest monthly average of thermal efficiency in March 2020 was (67.07%) and (49.7%) for the improved and conventional systems, respectively. The results also showed that the improved model retains the heat gained from solar radiation for a longer period compared to the conventional model at a constant solar radiation intensity. These improvements also contributed to a clear increase in the temperature of the air leaving the system, as the average difference in the temperature of the air entering and leaving the system reached in February to (23.34°C) and (19.28°C) for the improved and conventional systems, respectively. The results also proved that the improvements over the conventional system led to a reduction in the amount of heat lost from the solar air heater.

Conjugate Heat Transfer of Nanofluid Flow Inside A Micro– Wavy Channel

Hussein Jamal Almola; Amir Sultan Dawood

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 2, Pages 201-210
DOI: 10.33899/rengj.2021.129169.1078

Conjugate heat transfer method is utilized in this work for numerically studying the laminar two-dimensional forced convective heat transfers related to the aluminum oxide-water nano-fluid in horizontal micro wavy channel also the impact of adding nano-particles for constant heat flux applied at bottom the channel, The study assumed that the nanofluid is subject to the single phasic hypothesis that treats the basic fluid (H2O) and nanoparticles (Al2O3) as a homogeneous mixture and that the nano-fluid is incompressible and it has steady and laminar flow. The considered Reynold number and the nano particle volume fraction have been in a range between (500 and 2,000) and 2% respectively.   Use the (ANSYS FLUENT 2020 R1)software, which is one of the programs regarding the computational fluid dynamics (CFD), and Finite volume method (FVM) is selected to solve the governing equations For ensuring the accuracy of results, the CFD  result were verified with modern theoretical equation.  In this research four models are examined numerically, The first model is a flat channel and only water is flowing through it, The second model is a wavy channel and only water is flowing through it, The third model is a flat channel where the nanofluid consisting of water and nanoparticles (aluminum oxide) passe through it, and the fourth model is a wavy channel in which the nanofluid consisting of water and the nanoparticles ( AL2O3) passes through the channel for three different values of Reynolds number (500,1400,2000) and concentration of (2%) nanoparticles.  A micro-wavy channel represents an optimal state among all examined cases and with regard to all the Reynolds numbers. Furthermore, the best Performance evaluation criterion (PEC) is recorded for the case of wavy channel with nanofluid for Reynolds number equaling 2000.  At Re = 2000 with 2% as volume concentration, the value related to heat transfer coefficient equal to (4603.61) when using the nanofluid due to dispersion factors, Brownian motion, and nanoparticles that are responsible for enhancing heat transfer.  The presence of wavy channel and nanofluid flow enhance the nusselt number and improve heat transfer to fluid. It is noticed that when Reynolds number increases the pressure drop increases, the thermal resistance decreases, the heat transfer coefficient increases.  The addition of waves in the channel and nanoparticles increased the number of Nusselt and thus improved heat transfer.

Efficiency, Adequacy, and Uniformity for Normal Distribution of the Application Depths

Haqqi I. Yasin; Entesar Mhamad Ghazal

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 2, Pages 211-217
DOI: 10.33899/rengj.2021.129134.1075

The research aims to find a set of figures in case of the normal distribution of application depths that represent relationships for the parameters used to describe the performance characteristics of the irrigation system. Using 6010 values ​​for each of the dimensionless application depth, dimensionless cumulative area, and the coefficient of variation, with the help of the SPSS statistical program, an empirical equation was obtained to estimate the dimensionless application depth as a function of the dimensionless cumulative area and the coefficient of variation. Five figures were developed containing the relationships between dimensionless net depth of irrigation, application uniformity, coefficient of variation or uniformity coefficient, application efficiency or deep percolation losses, and storage efficiency or deficit coefficient.  By knowing two of these parameters, the rest of them can be easily found from these figures.

The Effect of Entrance Edges Shape of the Diversion Channel on the Dividing Streamlines Behavior at the Junction Region

Ahmed Yahya Abdalhafedh; Nashwan K. Alomari

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 2, Pages 218-226
DOI: 10.33899/rengj.2021.130181.1096

                  Diversion channels are used in irrigation networks and many of water resource projects. Due to the diversion of a portion of the water, a ratio of the main flow streamlines is deflected to the diversion channel (on the diversion side). The ratio of dividing streamlines increases from the surface to the bottom due to the high momentum of the flow upper layers,which resists its diversion. This negatively affects the quality of diversion water, as the largest proportion of it comes from the high sediment concentration of the lower layers. In this study, the effect of changing the sharp edge of the diversion channel entrance to a circular edge (at upstream, downstream or both sides) on the behavior of dividing streamlines. The study considered five different percentages of the diversion discharge ratio (between 7.5% and 30% of the total discharge) with five different diameters of the circular edge. The results indicated that there is a noticeable improvement of the dividing streamlines uniformity along the flow depth when using the upstream and downstream circular edge, as well as when using large diameter of the upstream circular edge only.  In addition, increasing the discharge ratio reduces the regularity of the flow lines.

Testing the Homogeneity of Rainfall and Temperature Data in the Kurdistan Region- Iraq

Rana M. A. Qasab Bashi; Abdel Wahab M. Younes; Omar M. A. Mahmood Agha

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 2, Pages 227-236
DOI: 10.33899/rengj.2021.130076.1095

In this study, the homogeneity test of the rain series and the observed monthly and annual temperatures was carried out using the following test methods: Pettitt test, Buishand test (BRT), Standard Normal Homogeneity test (SNHT) and Van Neumann test (VNT) at a confidence level of 5% for 9 stations registered in Various regions of Iraqi Kurdistan for the period from 1981-2020.
The missing values ​​for the rain time series were compensated using the simple arithmetic method and the normal ratio method. The missing temperature values ​​were compensated using the simple arithmetic rate method and via the NASA Teree satellite.
The results of the homogeneity tests of the monthly rain records data showed that most of the stations were homogeneous for the winter, spring and autumn months and were not homogeneous in the summer months. As for the data of the monthly temperature records, most of the stations had inconsistent data, except for the stations of Salah al-Din and Shaqlawa. The character of homogeneity prevailed over most of the months of the year. As for the annual data of rain and temperatures, the data of all stations became homogeneous after processing the monthly data.

Effect of Soil Surface Slope on Water Distribution Uniformity for Stationary Sprinkler Systems

Tariq Jasim Ahmed Al_farrajy; Haqqi I. Yasin

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 2, Pages 237-248
DOI: 10.33899/rengj.2021.130446.1105

The research included studying the effect of the slope of soil surface on water distribution uniformity of stationary sprinkler systems. 30 tests were conducted to obtain the pattern of water distribution along the radius of the wetting circle, where the sprinkler at the center, using 6 different sprinklers heads. In addition, different slopes of the surface were considered to study the wetting pattern, obtained by calculating the vertical deflection from the sprinkler head riser.  420 patterns of field water distribution were found for five slopes of the ground surface at seven different spacing, using rectangular and triangular arrangement of six sprinkler heads.
It has been concluded that both of the uniformity coefficient CU and the distribution coefficient DU decrease with the increase of the soil surface slope, (87.5% and 89% of the cases respectively). In addition, The mean percentages of maximum decrease in UC and DU due to the gradient increase from 0% to 20% for all sprinkler heads was 3.17% and 6%, respectively.and  the pattern of the water distribution does not change with the change of the soil surface slope, but rather the depth of water decreases and the range of the spraying increases as the negative slope decreases, and vice versa, the rate of water depth increases and the range of spraying decreases as the positive slope increases. Two equations were concluded to calculate the uniformity coefficient CU (or the distribution coefficient DU) for the distribution of water spray over lands with different slopes as a function of the slope and the uniformity coefficient CU (or the distribution coefficient DU) for the distribution of the water spray on flat surfaces with coefficients of determination of 0.98 and 0.977, respectively.

Infiltration and Some Physical Properties of Soil

Haqqi I. Yasin; Entesar M. Ghazal

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 2, Pages 249-258
DOI: 10.33899/rengj.2021.129941.1089

The research aims to study the effect of some physical properties of the soil as soil components of sand, silt, and clay, as well as bulk density, and the initial soil moisture, on both cumulative infiltration depth, infiltration rate, and basic infiltration rate.Depending on data of 31 laboratory infiltration tests represented by 516 values ​​for cumulative infiltration depth and cumulative infiltration time, including a wide range of change in soil physical properties. Using  the statistical program (SPSS), and by applying the nonlinear regression method, the best empirical equation has been derived to estimate the cumulative infiltration depth, with a determination coefficient of 0.975,  as a function of some physical properties of soil and in the form of Kostakov's equation to include  estimation of basic infiltration rate.

Appropriate Operating Policy for a Reservoir System Based on Inflow States (Mosul Reservoir as a Case Study)

Ziyad Taher Ali Al-Dabbagh; Kamel Ali Almohseen

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 2, Pages 259-266
DOI: 10.33899/rengj.2021.130561.1111

The present study has focused on the selection of appropriate operating policies for a reservoir system to maximize the hydropower generation through the derivation of operation rule curves for different states of the inflow into the reservoir. And in order to accomplish this task, 30 years of monthly observed inflow has been used and arranged into five intervals with lower and upper values of each interval. The Genetic Algorithms techniques were implemented to obtain the optimal operating policies for each of the proposed five categories of inflow. Furthermore, and in order to alleviate the adverse effects of trapping in local maxima, a hybrid method is suggested making use of the built-in functions of optimization available in the Matlab software. The non-linear optimization function used the values of the variables obtained by GA's as initial solutions required by the optimization process to reach global solutions. One of the main objectives of the current study was to build a simple mechanism to select the most appropriate operating policy which is compatible with the nature of the inflow state entering the reservoir during a certain period of time. Consequently, a simulation model was conducted using SIMULINK technique to mimic the Mosul reservoir system which is selected as a case study to test the proposed method. The results reveal an improvement by 10 % of hydropower generation over that produced over the 30 years of real operation using the current method.

Non-Stationarity Identification in Flow Time Series Using Wavelets Transform Technique

Reyan H. Al-Mustafa; Kamel Ali Almohseen

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 2, Pages 267-279
DOI: 10.33899/rengj.2021.130600.1113

 The current study explored the possibility of using  Discrete Wavelets Transform technique (DWT) in diagnosing the  non-stationarity in hydrologic time series, which typically masks the real characteristics of those series. This helps in diagnosing the appropriate model and using it for prediction purposes.
Basically, this manuscript divided into two phases: in the first phase, a defined stochastic linear model parameter,  i.e. (ARMA (1,1)) was developed with known parameters  1 and  of (0.8 and 0.4) respectively. The ACF and PACF analyses before and after intentionally adding some defined deterministic components (such as trend, periodicity, etc.) confirm the capability of (DWT)  in diagnosing those non-stationarity sources. While phase two makes use of (DWT) technique in diagnozing the non-statioarity in an observed flow time series of al-Khabor river, Kurdistan region-Iraq,  where 24 years of flow time series is available. After removing the source of the non-stainarity diagnozed by the proposed method in the data, a stationary model (ARMA (2,1)) has been fitted. The study indicated that the proposed model was distinguished by its capabilities to work in real time, thus, the outcomes of the model is almost following the same pattern of the observed outcomes of the process under study.

Evaluation of Aquacrop Model for Wheat Yield During Guaranteed Rain Years in Rabi'a Region

Alaa I. Naser; Entesar M. Ghazal

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 2, Pages 280-290
DOI: 10.33899/rengj.2021.130367.1098

AquaCrop model is an important tool for predicting and evaluating the impacts of environment and irrigation water management on crop productivity. The current study aims to evaluate AquaCrop model for wheat yield during years of guaranteed rain in Rabi'a rejoin and to study the effect of rain distribution on productivity.  with an attempt to suggest the best date for supplemental irrigation during the season to obtain the best productivity of wheat and irrigation water. AquaCrop model was calibrated with climatic and field data for Rabi'a region and start date of agricultural season was determined based on date and amount of valuable rain, with initial soil water content calculated for a root depth equivalent to 30 cm.
              The effect of rain distribution before sowing on productivity for different sowing dates (November 1, November 15, December 1, December 15, and January 1) was also studied. As well as determining the extent of need to add irrigation before sowing to improve productivity, in addition to determining the best date and depth of supplemental irrigation according to water need during wheat growth stages. . The results showed the importance of studying and observing the rain distribution before sowing and during the growing season, as delaying the sowing date can lead to an increase in productivity, as adding water with a depth of 20 mm was considered useful for improving productivity due to poor rain distribution. There was also a marked increase in productivity when adding supplementary irrigation of (60-70) mm during third or fourth stage of growth and according to the rain distribution for each year.

The Effect of Dual Water Jet on Discharge Coefficient of Vertical Spillway

Firas I. Khaleel; Ahmed Mohammed

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 2, Pages 291-299
DOI: 10.33899/rengj.2021.130443.1104

The water intakes is one of the important hydraulic installations that is built with the dam and is used to control the water level in the dam's lake. The vertical spillway is a type of intakes used in dams to control floods and as on intakes to change the river stream in mountainous areas. One of the most important problems that occur at vertical intakes is the vortex of water which occurs when the depth of submerge is less than the critical depth, dual water jet applied to the vertical spillway was used with different vertical and horizontal distances, the effect of dual water spillway was tested on six discharges entering the vertical spillway and the three diameters. The results shown that the dual water jet has a clear effect in dissipating the energy of the vortices formed at the vertical spillway, especially in the case of orifice flow, and it is effective in the large diameters of the vertical spillway.

Evaluation of Hidden Surface Removal Methods Using Open GL

Lubna Muzahim Saeed; Fakhrulddin H. Ali

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 2, Pages 300-308
DOI: 10.33899/rengj.2021.129472.1081

The research aims to address one of the complex problems that may be encountered when generating computer images for three-dimensional (3D) objects, which is the hidden surface detection and elimination. Several methods have been devised, through the last three decades, to solve this problem. However, the most popular methods used widely nowadays are depth or Z-Buffer (ZB) and Binary Space Partition Tree (BSPT). The first method (ZB) is very simple and more general but requires additional memory to store depth values in addition to intensity. On the other hand, (BSPT) method is more complex to implement but requires memory for pixel intensity only. Modelling graphical database in a binary tree make the dealing with parts of the database feasible. This is so important for clipping a part or more of the database when outside the viewing zone. 
The focus of this paper is to study these two methods, design an algorithm to implement each of them. After that a reasonable procedure is to found and applied for testing the performance of each of the two methods using exactly the same graphic load. A step by step increase of this load should be possible so that the behavior of the execution time at different complexity level and on average bases can be reported. The outcome results of the two methods should be compared and a recommendation to use which one of them is to be concluded [1]. Since one of the most popular graphics library which is being used during the last ten years and nowadays is the Open Graphic Library( OpenGL) from(Silicon Graphic Incorporation (SGI)[2], the algorithms of this work are implemented and the related software is carried out using this library with visual C platform.

A Review of Digital Image Fusion and its Application

Zahraa T. Al-Mokhtar; Farah N. Ibraheem; Hassan F. Al-Layla

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 2, Pages 309-322
DOI: 10.33899/rengj.2021.127928.1055

Image Fusion is applied to get back a group of data from two or more than two images and put it into one image to create additional wealthy information and profitable more than any of the input data that led to increase the features and performance of information.  The quality of the resultant data relies on the implementation of the process. Image fusion is excessively utilized in stereo camera fusion, medical application, manufacture process monitoring, electronic circuit design and inspection, complex machine diagnostics and in intelligent robots on assembly lines. This study displays a literature review on different types of algorithm and theories which apply on images. Many quality criteria have debated to do a brief comparison of these methods. The applications of image fusion are showed in this paper.

Low Cost Portable System for Converting Mosul Electrical Substations to Smart One’s

Aseel Y. AlKasap; Rabee M. Hagem

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 2, Pages 323-339
DOI: 10.33899/rengj.2021.130620.1115

Today electricity supplement still has power failures and blackouts due to the lack of automated analysis and the utility's low visibility over the grid. Small and undetected electrical problems can have far-reaching consequences. These failures cause not only high-energy losses, but also costly unscheduled outages, severe injury to employees, and even a fire. Therefore, the monitoring of electrical substations is essential to detect faults and ensure long-term safe operation, safety, protection, and reliability. Internet of things technology provides the possibility of obtaining station data in real-time. In this research, two systems were designed, implemented, and tested in high voltage electric stations. The first part is designed to obtain data on the environmental conditions at the substations, and the important parameters from the transmission lines at the substations in real-time, which help to prevent power outages by relying on engineers who can analyze comprehensively the electrical energy. The system also provides the Automatic Under Frequency Load Shedding ability if the frequency in the stations falls below the normal limit, which contributes to maintain the efficiency and the quality of electrical energy in the substations, and provides protection for the substations. The second part is designed to obtain the values of the parameters that determine the electrical transformers' conditions and monitors the status of the line in terms of switching off and on in real-time at the substations. Thus, these proposed systems are transforming the traditional substations into smart substations. The performance of the system is introduced based on correlation of data and percentage error. The best correlation was for the current data and the least percentage error was for the current. We strongly believed that the proposed system is vesible.

Assessment and Review of the Reactive Mobile Robot Navigation

Zead Mohammed Yosif; Basil Shukr Mahmood; Saad Zaghlul Al-khayyt

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 2, Pages 340-355
DOI: 10.33899/rengj.2021.129484.1082

Nowadays, the mobile robot can be seen in different fields of engineering and science. The mobile robot can do some tasks that are so difficult or very risky to be performed by a human. Most of the works currently focus on implementing artificially intelligent algorithms and other algorithms that depend on the behaviour of nature. These approaches have been used in mobile robot navigation along uncertain manner. Mobile robot navigation strategies can be divided into two approaches: the classical approach and reactive approach. The classical approach related to static environment, whiles the reactive navigation is based on an unstructured environment. Path planning is one of the most important parts of the navigation system. In this paper, review and assessment of path planning strategies that can concern with the reactive approach are discussed, because it deal with the problem of dynamic environment.  Numerous reactive methods have been introduced. Most of these presented works were concerned with simulation and a few of them have shown experimental implementation. Many papers tried to make a combination between two algorithms or more to increase the efficiency. It is concluded that reactive algorithms need more learning phases, complex in design, and require large memory storage.

Analysis of Rainfall Drought Periods in the North of Iraq Using Standard Precipitation Index (SPI)

Anass M. M. Rasheed

Al-Rafidain Engineering Journal (AREJ), 2010, Volume 18, Issue 2, Pages 60-72
DOI: 10.33899/rengj.2010.28187

In this research, the standard precipitation index (SPI) was used to analyze rainfall records between 1941 - 2002 for nine metrological stations in the north of Iraq. In addition, digital maps of average drought magnitude and average drought intensity for the study region had drawn by using geographic information system (GIS). It is concluded that 56% of the study period were drought years.

The Effect of Power Swing on Distance Relays Performance

Atheer Habash Abosh; Abdul Ghani A. Abdul Ghafoor

Al-Rafidain Engineering Journal (AREJ), 2009, Volume 17, Issue 5, Pages 43-48
DOI: 10.33899/rengj.2009.43386

Abstract
The distance relay is suffering from under-reach in its performance. This is because of some transient disturbance, which may happen when the power flows and swings. Besides that the power swings as a consequence of some fault cases. In this paper a new distance relay has been suggested and modeled for detecting stable and unstable power swings.
This relay is known as out of step relay (OOS). The method employed is to measure the rate of change of the positive sequence impedance of the relay which supervise the trip signal that comes out of the distance relay. It allows the distance relay to work, if it detects an unstable power swing or a fault. On the other hand it blocks it if the power swing is stable. The new relay have been modeled and simulated using MATLAB-SIMULINK software programs.
The performance of this relay has been tested on an equivalent two sources system. The results prove that the suggested relay is active and fast. Thus overcoming the limitation of the distance relay in case of under-reach. The results also show that the new relay has the ability in discriminating between the types of faults, that occur during power swings.
Key Word: Power swing, Distance relay , Out of step protection technique.

Experimental Study of the Behavior of Fiber Reinforced Concrete Beams under Repeated Loads

Dr.Bayar J. Al Sulayfani; Muna M .Abdullah; Samier S. Shmas

Al-Rafidain Engineering Journal (AREJ), 2010, Volume 18, Issue 4, Pages 1-9
DOI: 10.33899/rengj.2010.31560

Abstract:
Concrete behavior subjected to repeated loads is differs than the one subjected to static loads. Repeated loads caused crushing in some part of concrete due to loading and unloading process. Concrete behavior under static loads is affected by adding steel fibers, which improved many properties especially concrete tensile strength. These improvements are studied in this research under the effect of repeated loads, by testing simply supported fibrous reinforced concrete beams with dimensions (1000x150x160) mm, reinforced with different percentages of steel fibers (0.0, 0.5, 0.75, and 1.0%). Repeated loads were applied to the beams through two points and for many cycles up to failure. The physical properties and compressive strength of the concrete used was found by casting standard cylinders (150x300) mm for the different percentages of fibers. All the results show improvements in beams behavior due to fiber addition to the concrete under repeated loads, by increasing the deflection, strain, ductility and energy dissipation due to increasing of added fibers percentages.

Keywords : Repeated load, Reinforced Concrete, Beams, Steel fiber

Use Of Bentonite Clay As A Coagulant Or A Coagulant Aid With Ferrous Sulfate For Synthetic Turbidity Removal

Mohammad S. Hassan; Musa’b A. Al- Tamir

Al-Rafidain Engineering Journal (AREJ), 2006, Volume 14, Issue 4, Pages 46-58
DOI: 10.33899/rengj.2006.45374

Abstract
In this study the bentonite clay has been used as a coagulant and coagulant aid with ferrous sulfate in turbidity removal for different initial synthetic turbidity of Tigris River samples of (10- 500) ntu, The study revealed the efficiency of using bentonite clay as a coagulant alone in removing turbidity with a dose not more than 30 mg/l, Also the study reveled the improvement of ferrous sulfate efficiency for removing water turbidity when bentonite clay used with it in a dose of 7.5 mg/l of bentonite and 5 mg/l of ferrous sulfate. The regression analysis showed that the most important variables affecting on turbidity removal were initial turbidity followed by settling time and bentonite clay dose then finally ferrous sulfate dose.
Key Words: Ferrous Sulfate, Iron Salts, Bentonite Clay, Coagulation, flocculation, Coagulant aids, Turbidity removal, Water Supply

Compressive and Tensile Strength of Natural Fibre-reinforced Cement base Composites

Dr M. A. Ismail

Al-Rafidain Engineering Journal (AREJ), 2007, Volume 15, Issue 2, Pages 42-51
DOI: 10.33899/rengj.2007.44954

ا
Abstract:

This paper describes the effect of the addition of various volume fraction (0-%4) of short natural fibres on the behavior of the composites. An experimental work has been carried out to study the mechanical properties of Roselle fibre-reinforced cement composites. The results show that the tensile strength of composite increases, (this increase in strength is about 53%), while the compressive strength decreases as the fibre volume fraction is increased.
Keywords: Cement , Composites ,Compression , Mechanical Properties Natural Fibre ,Roselle Fibre, Strength, Tensile.

Concepts Architecture For Architectural Students

Imad M. M. Azhar Al-Bakari

Al-Rafidain Engineering Journal (AREJ), 2007, Volume 15, Issue 4, Pages 80-93
DOI: 10.33899/rengj.2007.45256

Abstract
Formation of concept in Architecture Design is something unusual to many student and most projects been designed with no knowledge of how to use concepts properly.
This research introduce meaning and form of concepts in Architecture. Range and scope in Academic and professional work. Also problems, which face student such as Communication, Adaptation, and the correct type, show types of concept. Research also shows types of concept and concepts hierarchies.
Applied part of this research will deal with some student' projects. Who adapt concepts. And to analyze forms and types of their concepts through different tables. Inter views have been made with students of fourth year to discover how students had been arrived to final solution

Evaluating performance of Hydrus-1D model in simulating evaporation from soil surface for different wetting intervals

Muzahim M. Abid; Eftikhar A. Alani; Entesar M. Ghazal

Al-Rafidain Engineering Journal (AREJ), 2015, Volume 23, Issue 2, Pages 31-43
DOI: 10.33899/rengj.2015.101073

In this study, Hydrus-1D model was used to simulate the evaporation from the soil surface for different wetting intervals for northern region(sandy loam and clay loam) using input for climatic data , and data of class Apan evaporation.The results showed that data of pan evaporation class A can be relied on in simulating and calculation of evaporation from the soil surface, where the standards of statistics (IOA, R2) calculated on the basis of evaporation pan class A data are better for the wetting intervals (2,4, 8, 16 ) days compared with the values of those standards based on full climate data and both types of soil. The study also showed that the wetting intervals and their impact on evaporation from the soil surface and evaporation stages reasonably agree with the results of field experiments that have been made in this area.

Using Intelligent Techniquesin Sustainable Buildings

Sinan Mohammad Talee

Al-Rafidain Engineering Journal (AREJ), 2019, Volume 24, Issue 2, Pages 39-55
DOI: 10.33899/rengj.2019.164354

Intelligent techniques represent integration between building system and technology. The merge of these techniques within a building serves and eases our life. Intelligent techniques became a common concept that defines the highest levels of various standards, which determine indoor environmental health. In other words, they increase productivity, raise prosperity, as well as enhancing the efficiency of resources, cost, flexibility, and adaptability. Thus, intelligent techniques reflect the concept of sustainability, as their effects cover all the main building aspects of function, structure, and form. The study considers form as the most obvious affected aspect of a sustainable building, especially as the intelligent techniques and materials formed the building envelope.
 
 The research is conducted on case-study samples from the region of Arab Gulf, which have a hot desert climate that is similar to the third desert climate in Iraq. The study defines the research problem as The knowledge insufficiency of the formal aspect identifications (with various classifications) that affected by intelligent techniques of sustainable buildings in the hot desert climate. The research aims to determine the aspects affected by intelligent techniques of the sustainable building in general and to verify their role and impact on the formal aspect of the façade design that can achieve the sustainability standards. Further, the samples of the case-study location in the hot desert climate aim to employ results on our local architecture in Iraq particularly.
 
The study defines its own structure and methodology in order to achieve its goals and solve the research problem, by dividing the research into several stages. Starting from defining the concept of the intelligence, and exploring previous studies to represent the theoretical framework. Then, listing the case-study samples, and measuring them using the descriptive analysis method, by analyzing the critical contexts upon the selected samples. The research concluded important points of the impact of the intelligent techniques on the formal aspect of the building. As the harsh conditions of the hot desert climate represent itself as a main challenge in the process, building protection against solar radiation and incandescent is vital. That is possible by methods of stirring, resistance, modulation, the control of the intelligence and the sustainability of the exterior materials.

Corrosion Protection of Steel Pipe Samples Buried in Soil

Haitham M. Wadullah

Al-Rafidain Engineering Journal (AREJ), 2010, Volume 18, Issue 5, Pages 1-10
DOI: 10.33899/rengj.2010.32798

The types of corrosion protection on corrosion resistance of steel pipe samples buried in soil have been studied in this research. Samples of unprotected carbon steel are used with other protected by different corrosion protection such as galvanic coating, rubber coating and two types of cathodic protection (impressed current and sacrificial anodes). The weight loss technique is used as a function of the corrosion rate (mdd).
The results, which have been obtained, show that the corrosion rates in the unprotected samples are high compared with the corrosion protected samples, and the maximum corrosion resistance is found to be at the cathodic protection systems.

Key words: Corrosion protection, Samples of steel pipe, Buried in soil

Friction and indicated power measurement for diesel engine by ( aerial dynamometer

Mohammad Sami Ahmad

Al-Rafidain Engineering Journal (AREJ), 2012, Volume 20, Issue 2, Pages 106-115
DOI: 10.33899/rengj.2012.47288

Abstract:
The conventional methods - used for - measuring brake, friction, and indicated power are based on brake - off dynamometers which use hydraulic or electrical dynamometers .
The mentioned above methods use the measured torque to calculate the related power.
The present method and instrument are characterized by measuring the amount of pressure opposed by a compressor joined to the engine and a reservoir for a compressed air, thus; the engine speed decelerates with the increasing pressure . For a specified pressure and engine speed, power could be calculated.
In addition, friction power in the engine could be estimated by measuring the consumed current and effective voltage on an electrical driving motor when the diesel engine at run – off situation; no fuel supply. The whole present dynamometer had been designed and performed by the researcher as explained.

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