Journal of Engineering

Crime is one of the important phenomena that has been studied globally, with planners and architects working to control this phenomenon to achieve security. This study is particularly important for high-density residential complexes due to the influence of crime on human behavior and the sense of security within them. The research identifies a knowledge problem related to the lack of comprehensive scientific knowledge regarding the determinants of a safe environment for high-density residential complexes in city centers and the impact of various types of crime. The aim of the research is to establish more comprehensive knowledge regarding the planning, design, and social determinants necessary to create a safe built environment for high-density residential complexes in city centers. The research focuses on key concepts such as spatiality, visual surveillance, privacy, and social interaction, proposing that residents' sense of safety increases in more organized environments at both the planning and design levels within their social determinants. Based on this, a knowledge base was established regarding the phenomenon of crime and its causes, including definitions of its basic terms and patterns, internal and external factors associated with it, and major theoretical approaches. The research then derived planning, design, and social determinants to mitigate crime. The results of the research provide clear mechanisms to achieve the concept of security, including indicators for planning and design treatments for high-density residential complexes within their social determinants. These mechanisms offer designers guidelines to create safer built environments for their users.

This study examines the geotechnical properties of the soils in the provinces of Baghdad, Diyala, Wasit, and Babylon. The research involves exploration, comparison, and analysis methods to collect and analyze data, and then draw geotechnical maps for each characteristic at various depths. Key soil properties assessed include soil texture, moisture content, density, shear strength, and compressibility. The results highlight significant variations in soil properties across the different provinces, which are critical for infrastructure planning and construction. The study provides a comprehensive reference for engineers and planners to understand the geotechnical conditions of these regions.

The Romantic thought in architecture emerged as a reaction against the strict rationalism of the Enlightenment and the industrialization of the 19th century. It emphasized emotion, individualism, and a connection to nature. This movement sought to revive the medieval Gothic style, which was seen as more expressive and spiritually uplifting compared to the classical forms. Romantic architecture often features Gothic elements such as pointed arches, ribbed vaults, and flying buttresses, along with organic forms, curves, and natural motifs. The use of light, shadow, and color was intended to evoke emotions and create a dramatic impact. The study explores key examples and architects associated with this movement, highlighting their contributions to the development of Romantic architecture.

The concept of social sustainability in traditional urban structures is critical for maintaining and enhancing the social fabric of communities while ensuring that development meets the needs of present and future generations. This study explores key mechanisms to achieve social sustainability in traditional urban structures, including the sustainability of the kinship system, the Waqf (endowment) system, and the integration of religious factors. By strengthening family and community ties, utilizing endowments to support social services and infrastructure, and incorporating religious and cultural practices into urban planning, traditional urban environments can be preserved and enhanced. The research provides insights into how these mechanisms create a balanced and inclusive urban environment that respects and preserves the unique characteristics of traditional urban structures.

This research investigates the behaviour and load carrying capacity of reinforced concrete columns exposed to fire flame. The experimental program included casting and testing 128 column specimens divided into two series with target compressive strengths of 30 and 40 MPa. Each series was further divided into three main groups loaded eccentrically with eccentricities of 30mm and 80mm. The study found that the predicted load carrying capacity by three codes (ACI-318/08, BS-8110/97, and Canadian/84) was unconservative after burning. The BS Code equation was found to predict load capacity after exposure to high fire temperature levels better than other codes. Load-deflection curves indicate a deleterious response to fire exposure, and it was noticed that the maximum crack width increases with increasing fire temperature and spacing between lateral steel ties.

This paper investigates the relationship between the liquid limit and the coefficient of consolidation of Iraqi soils. The study utilized undisturbed silty clay samples taken from various locations and depths in the Middle and South of Iraq, in cooperation with the Consulting Engineering Bureau- University of Baghdad- College of Engineering. The samples were tested to determine their liquid limit and coefficient of consolidation. The relationship between these two parameters was plotted as a curve, which was then compared with curves from other studies. It was observed that the curves closely align when the liquid limit is around 60, but diverge when the liquid limit is either lower or higher than 60. This indicates that the coefficient of consolidation for Iraqi soils can be estimated based on the liquid limit.

This study investigates the electrochemical decolorization of direct black textile dye in the presence of sodium hydroxide (NaCl). An electrochemical cell with graphite electrodes for both anode and cathode was constructed. The decolorization percentage, treatment time, power consumption, and pH were studied as functions of the applied voltage and salt concentration. Results show that decolorization increases with increasing salt concentration and applied voltage. The best decolorization of 86% was achieved after 17 minutes at 7 volts and 5 g/l salt concentration. Further decolorization can be achieved, but this will be accompanied by a sharp increase in power consumption. No significant decrease in pH value was observed at the end of each experiment.

This paper presents a new fast sealed lead acid (SLA) battery charger designed to charge fully discharged batteries in a short time while monitoring the battery state of health to prevent overcharge and extend battery life. The design was implemented practically, and 150 chargers of this type were produced for commercial use. These chargers are now in service at various mobile base station sites around Baghdad. The charger can charge a fully discharged 12V, 4.5Ah battery in less than 5 hours and supply PLC control systems with DC power for about 24 hours of continuous operation during main electricity faults. Over one and a half years of continuous operation, three faults were recorded, all due to bad component manufacturing.

This paper describes DC motor speed control based on pole assignment feedback control technique. The present pole assignment technique specifies all closed-loop poles. Such a system where the reference input always zero is called a regulator system. The problem of shifting the regulator poles (closed-loop poles) at the desired location is called pole assignment problem, and this can be done if and only if the system is completely state controllable. Controller's objective is to maintain the speed of rotation of the motor shaft with a particular step response. Results obtained were compared with another controller applied to the DC motor based on Proportional Integral Derivative (PID) control. The controller was designed and tested using MATLAB 7 programming language.

This study investigates the sediment transport capacity of the Tigris River within Al Mosul City. A steady one-dimensional mathematical model was implemented using HEC-RAS (Version 3.1.3) software, incorporating recorded field measurements for calibration and verification. The model estimated flow velocity and sediment transport capacity for discharges ranging from 50 to 1500 m³/sec. The study identified locations of low flow velocity and compared sediment capacity rating curves for different cross sections. It was found that sediment transport capacity at cross sections 13,000 m and 4,500 m from the end of the reach, before and after Al Khosar River, was lower than other sections. The comparison of sediment transport capacity and inflow sediment quantity showed significant deposition before and after Al Khosar River. To avoid sediment deposition, the inflow discharge from Al Mosul Dam must be at least 1500 m³/sec, and to avoid deposition after Al Khosar River, the total discharge must be at least 780 m³/sec. The study suggests developing the river reach cross section with low flow velocity to increase sediment transport capacity.

This study investigates the sediment transport capacity of the Tigris River within Al Mosul City. A steady one-dimensional mathematical model was implemented using HEC-RAS (Version 3.1.3) software, incorporating recorded field measurements for calibration and verification. The model estimated flow velocity and sediment transport capacity for discharges ranging from 50 to 1500 m³/sec. The study identified locations of low flow velocity and compared sediment capacity rating curves for different cross sections. It was found that sediment transport capacity at cross sections 13,000 m and 4,500 m from the end of the reach, before and after Al Khosar River, was lower than other sections. The comparison of sediment transport capacity and inflow sediment quantity showed significant deposition before and after Al Khosar River. To avoid sediment deposition, the inflow discharge from Al Mosul Dam must be at least 1500 m³/sec, and to avoid deposition after Al Khosar River, the total discharge must be at least 780 m³/sec. The study suggests developing the river reach cross section with low flow velocity to increase sediment transport capacity.

his paper proposes a new algorithm to generate variable length random binary sequences by selecting different points from hashed digital images. The selecting process is organized to ensure randomness and avoid regeneration of the same sequence within a year. The generated sequences are tested to meet the National Institute of Standards and Technology (NIST) criteria. The proposed algorithm eliminates the need for traditional key exchange, providing a security advantage. This algorithm is capable of generating random binary sequences that meet the security requirements of cryptographic algorithms.

This study investigates the performance of a plate heat exchanger (PHE) for indirect evaporative cooling under Iraqi conditions. The performance variation was analyzed based on heat exchanger dimensions, plate spacing, inlet air velocities, and inlet air temperatures. The momentum and energy equations were solved in three dimensions using FLUENT 5.3 software, and heat exchanger performance parameters were extracted from the post-processing of the numerical data. Additionally, a two-dimensional fluid flow and heat transfer numerical analysis for the crossflow PHE was conducted. The results indicated that indirect evaporative cooling could be applied to obtain suitable outlet air temperatures for low and medium values of wet-bulb temperatures in arid climates. The maximum thermal gradient for both air streams occurred at an inlet air velocity of 0.5 m/s, while the minimum occurred at 5 m/s. The greatest thermal gradient for both air streams occurred at a plate spacing of 3 mm and decreased progressively to the lowest gradient at 10 mm spacing.

This paper presents a two-dimensional finite element model to study the thermal history and thermomechanical process in the butt-welding of aluminum alloys using friction stir welding (FSW). The model incorporates the mechanical reaction of the tool and the thermomechanical process of the welded material. The heat source in the model involves the friction between the material and the probe and the shoulder. The effects of welding parameters such as preheating (100, 200°C), rotational speed (960, 1200 rpm), and linear speed (110, 155, 195 mm/min) on the temperature distribution of Al Alloy are studied. The results show that preheating the workpiece before the process is beneficial to FSW. The calculation results indicate that the temperature distribution is significantly affected by the welding parameters.

Two dimensional turbulent natural convection heat transfer and fluid flow inside an air filled inclined square enclosure differentially heated has been numerically studied. Fully elliptic Navier- Stockes and energy equations are solved using finite volume method. The problem is simulated for different angles of inclination (.deg1800≤≤θ) and Rayleigh numbers (1681010≤≤Ra). The turbulence k-є model is used to model the effect of turbulence. The wall function approach is used to model the regions near the walls of the enclosure. The obtained results from this study show that the rate of heat transfer is increased with the increase of Rayleigh number and decreased with the increase of angle of inclination(.deg900≤≤θ).Also the induced vortices are strongly elongated with increase of Rayleigh number. The thickness of thermal boundary layer is decreased with the increase of Ra. The validation of the present code was done by comparing the computed results with the published ones. The comparison indicated a good agreement.

This study investigates the influence of natural convection due to buoyancy on the laminar upwards air flow in a uniformly heated inclined circular cylinder. The investigation covered a wide range of Reynolds number (450≤Re≤2008), heat flux (95 ≤ q ≤ 898) W/m², Rayleigh number (1.1132×10^5 ≤ Ra ≤ 3.6982×10^5), with different angles of cylinder inclination (α=0° (Horizontal), α=30°, α=60° (Inclined), and α=90° (Vertical)). Results show that the heat transfer process improves as the angle of inclination moves from vertical to horizontal position. A general empirical equation for average Nusselt number Num as a function of Rayleigh number Ra, Reynolds number Re, and angle of inclination α was obtained.

Optimal design of three links and four links serial manipulator involves striking a balance between an appropriate link length, radius, link exact end effecter deflection and the amount of stress induced in each link. Optimization has been applied for getting a minimum robot weight through making the robot arm section tapered while keeping the first link as cylindrical tube as it represent the robot base only. The synthesis optimization problem involves setting up guess values for links length and radius subjected to constraints of deflection, stress and geometric constraints of total robot length. The optimization process focuses on minimization of robot weight as an objective function, the guess values has taken from three links manipulator and the industrial robot as four links serial manipulator. The results of optimization has been plotted and represented through the different relations between the design parameters (Link radius, length and total robot deflection, total robot weight, stress...etc). The results shows a good agreement minimizing the total deflection to(2x10-5 m) with this degree of precision an optimum design features may be obtained that gives a robot structure with high stiffness and minimum weight that enables the robot to do its tasks with minimum inertia effect.

This study investigates the performance improvement of a hydrostatic transmission control system using a radial basis neural network (RBNN) controller. Pump-controlled motors (PCM) are preferred power elements in many applications due to their high maximum operating efficiency. However, the dynamics of hydraulic systems are highly nonlinear and can be subjected to non-smooth and discontinuous nonlinearities. Conventional Proportional, Integral, and Derivative (PID) controllers cannot cope with these nonlinearities and variations in system parameters. Therefore, an RBNN controller is proposed to control the speed response of PCM. The RBNN controller's structure is simple and efficient for control purposes. The performance of PID and RBNN controllers was assessed based on speed behavior improvement and their ability to compensate for changes in system parameters (load and bulk modulus). Results showed that the RBNN controller is more robust and provides better performance compared to the classical PID controller. Additionally, further improvement in speed dynamics can be achieved with appropriate tuning of RBNN parameters.

This study investigates the effect of using the Magnetic Abrasive Finishing (MAF) method for finishing flat surfaces. The results indicate that MAF can form optimum physical mechanical properties of the surface layer, remove defective layers, and decrease the height of micro irregularities. The study also compares the surface quality parameters after MAF with those achieved through grinding. The findings suggest that MAF is a promising technique for finishing flat surfaces, offering improved surface characteristics compared to traditional methods.

This study investigates the effective embedded length of longitudinal reinforcement bars in self-compacted concrete (SCC). Eight reinforced concrete beams were tested, with six beams using SCC and two beams using normal concrete. The beams were subjected to two-point loads, and measurements of slip and strain at the reinforcement bar ends were taken. The study examined the influence of bar diameter and available embedded length on bond stress and failure mode. Results indicate that increasing bar diameter slightly decreases bond stress, while increasing embedded length decreases bond stress and improves failure mode, especially for smaller bar diameters.

This study presents an idealization scheme for the analysis of rectangular storage tanks acted upon by earthquake excitations. Above and below ground tank, uses have been considered. A linear three-dimensional finite element analysis has been used to predict the natural frequencies. Analysis parameters are the ratio of height to length of the tank, the type of soil, level of water in the tank, and also the wall thickness. The results for top displacement and axial force components for a full tankabove ground case have values greater than those in half- full (31%) and empty tank cases (75%). At the opposite of that, the underground tank demonstrates that top displacement and axial force components for an empty tank case have values greater than those in half- full (19%) and full tank cases (40%). The base shear for above ground tank case has values greater than those in underground tank cases (19% to 37%). The shear base for soil type 2 is greater than those in soil type 1(17% to 28%).

E-learning comprises all forms of electronically supported teaching and learning. The information and communication system, whether networked or not, serve as specific media to implement the learning process; Computer based learning is one of the applications and processes of E-learning, sometimes abbreviated to CBL, refers to the use of computers as a key component of the educational environment [2]. Through my teaching, I found that there is a need for software learning packages at the lab to help students understand their courses especially in the subjects that need imagination like data structure. This research presents a data structure learning package for array and linear structure. Linear structure covers non-linked structure (stack and queue) and linked structure with their kinds.Through out this project the students can obtain a demonstration of how data structure is represented in memory. Most of the windows consist of three tabs, the first one is the information tab which contains all the information about the structures. The second tab contains all the operations performed on it and there is an ability to display all the operations in one executable program (full program), which receives inputs from the students, the students can enter different inputs according to the choices displayed and produce output after implementing by C++ program. The third tab contains exercises for the students to test their ability in understanding and after completing all the questions the package gives a score depending upon solutions. The package includes pictures and demos (movies) that represent the data structure implemented with 3D Max, finally all the windows are supplied with voice (my voice) to teach the students how to use the package.

The effect on aerodynamic drag of a truck by controlling the boundary layer separation using a rotating cylinder on leading edge of the truck-trailer is investigated numerically. The flow was assumed to be steady, incompressible, turbulent, and two-dimensional passing over the top surface of the truck. The boundary condition for all the boundaries of the truck was set as well as the cylinder was treated as a moving wall with a specific rotational velocity. The developed computational algorithm is tested for the flow over a flat plate (8m) long with various free stream inlet relative velocity (U∞) which are considered the same as truck velocity and has the values (40, 60, 90, and 120) km/h. The effect of cylinder diameter (10,20,30,and 40) , rotational speed (1000-5000 r.p.m) and free stream velocity on the aerodynamic drag and pressure distribution of the flow field were investigated. The governing equations which used are the continuity, momentum, and the (K-ε) turbulence model. These equations are approximated by using a finite volume method, with staggered grid and modified SIMPLE algorithm. A computer program in FORTRAN 90 is built to perform the numerical solution.The numerical results show that, the optimum cases for inlet free stream relative velocity (U∞) values( 40,60) km/h, a significant reduction of drag coefficient equal to 80% and 77% respectively was obtained by useing a speed of rotation and diameter size equal to 5000 r.p.m and 40 cm , for (U∞) value( 90 )km/h a reduction equal to76%, and for (U∞) equal to (120) km/h a reduction equal to 60% was obtained . These optimum results lade to reduce the effect of the aerodynamic drag on the vehicle by delaying the separation zone of boundary layer and enhancing the pressure gradient of the flow field. Comparison of the results with the available previous published experimental and fluent program results was investigated.

The aim of this work is to study reverse osmosis characteristics for copper sulfate hexahydrate (CuSO4.6H2O), nickel sulfate hexahydrate (NiSO4.6H2O) and zinc sulfate hexahydrate (ZnSO4.6H2O) removal from aqueous solution which discharge from some Iraqi factories such as Alnasser Company for mechanical industries. The mode of operation of reverse osmosis was permeate is removed and the concentrate of metals solution is recycled back to the feed vessel. Spiral-wound membrane is thin film composite membrane (TFC) was used to conduct this study on reverse osmosis. The variables studied are metals concentrations (50 – 150 ppm) and time (15 – 90 min). It was found that increasing the time results in an increase in concentration of metal in permeate, feed concentration in feed vessel and recovery percent. While, it was found that water flux, rejection percent and mass transfer coefficient is decreasing with increasing operating time. Also, it was found that the permeate concentration and feed concentration in feed vessel increases with increasing feed concentration, on the contrary, water flux, the percentage of recovery, rejection percent and mass transfer coefficient decreases with increasing the concentration of feed solution. The maximum rejection of copper, nickel, and zinc salts are 96.6%, 95.7% and 98.2% respectively. The maximum recovery percentage of copper, nickel, and zinc salts are 40.8%, 41.35% and 38.44% respectively. The pure water permeability constant was calculated for TFC membrane.