Journal of Engineering

This paper explores the optimization of service distribution in urban and regional planning using buffer zones techniques. The study focuses on the distribution of secondary schools in a sector of Baghdad, utilizing Geographic Information System (GIS) tools to overcome various planning challenges. By accurately allocating geographic sites and rapidly achieving multiple planning requirements, the research demonstrates the effectiveness of buffer zones (zones of influence) in urban planning. The findings highlight the importance of precise site selection and the use of GIS in achieving equitable service distribution.

This paper examines the architectural transformations in holy cities, with a focus on the holy city of Najaf as a model. The study highlights the significant impact of increasing human needs, cultural progress, and technological advancements on the traditional urban fabric of these cities. The research identifies the challenges faced by Najaf, including the disruption of its traditional architectural style due to the introduction of foreign architectural elements. The paper emphasizes the lack of public awareness and state policies for preserving historical and sacred cities. The study proposes a comprehensive approach to preserving the unique identity and heritage of Najaf, ensuring that future generations can appreciate its historical and cultural significance.

This paper explores the critical aspects of cost management and planning in construction projects. Effective cost management ensures that projects are completed within budget, maintaining financial stability and project success. The study covers various stages of the project lifecycle, including cost estimation, budgeting, cost control, and financial management. It also discusses the importance of resource allocation and risk management in achieving project objectives. The paper provides insights into best practices and strategies for managing construction costs, highlighting the significance of accurate planning and continuous monitoring throughout the project.

يهدف هذا البحث إلى دراسة تأثير المثيرات البصرية على الأطفال في مستشفيات الأطفال، وكيف يمكن أن تساهم في تحسين البيئة الداخلية لتحقيق بيئة علاجية ملائمة. تم تطبيق الأسس النظرية للبحث على بيانات معمارية منتخبة لاختبار صحة الفرضية، وتم استخلاص النتائج التي توضح أهمية الألوان والضوء والمناظر الطبيعية والإشارات في تحسين الإدراك البصري للأطفال وتقليل محاوفهم. البحث يشير إلى أن تصميم الفضاءات الداخلية بشكل يساهم في تحقيق الأمان النفسي والسلامة للأطفال، مما يسهم في تسريع عملية الشفاء.

This paper presents a nonlinear three-dimensional finite element analysis to predict the load-deflection and moment-rotation behaviors of composite beams consisting of preflex steel sections encased in concrete. The analysis is conducted using the finite element computer program ANSYS V. 10. The study introduces cambering of the steel section and examines the effects of mesh refinement on the results. The findings show that using preflex steel sections can increase the ultimate load capacity of the composite beams by approximately 15%, with deflections and rotations being significantly lower compared to beams without preflex sections. The results are validated against experimental data, demonstrating good agreement.

This paper presents experimental investigations on the behavior of reinforced concrete flexural beams strengthened or repaired with Carbon Fiber Reinforced Polymer (CFRP). The study involved 14 test beams, which were subjected to two-point loading in a simply supported span. The beams were tested in both strengthened and repaired conditions to compare their performance. The results show that using CFRP as external reinforcement significantly enhances the ultimate load capacity, alters the crack pattern, and reduces deflection. The findings suggest that CFRP can increase the ultimate load capacity by up to 160% compared to untreated beams. This research highlights the effectiveness of CFRP in improving the structural performance of reinforced concrete beams.

This paper proposes a modified version of the Adjusted Step Size Least Mean Square (ASSLMS) algorithm, named Modified Adjusted Step Size LMS Algorithm (MASSLMS). The new algorithm addresses the drawback of requiring prior statistical knowledge of the input signal to determine the fixed maximum step size in the initialization stage of the ASSLMS algorithm. Instead, MASSLMS calculates an appropriate time-varying maximum step size based on the instantaneous energy of the input signal vector. This time-varying upper bound ensures the stability of the adjusted step size, which is recursively adjusted based on a rough estimate of the performance surface gradient square. Computer simulation results demonstrate that MASSLMS achieves faster convergence and lower steady-state miss-adjustment compared to the standard LMS and ASSLMS algorithms for three different types of channels in adaptive linear equalizer systems.

This study investigates the hydroisomerization of n-alkanes (C5-C7) over a 0.32wt%Pt/HY-Zeolite catalyst within a temperature range of 240-270°C, liquid hourly space velocity range of 1-3h-1, and hydrogen to n-alkane mole ratio of 8-24 under atmospheric total pressure. The research examines the effects of hydrogen and n-alkane partial pressures on the overall reaction rate, determining reaction orders and apparent activation energies. The results indicate that for nC7, the reaction order with respect to hydrogen varies between -0.998 and -0.948, while with respect to nC7 it varies between 0.154 and 0.156. For nC6, the reaction order with respect to hydrogen varies between -0.811 and -0.808, and with respect to nC6 it varies between 0.332 and 0.337. For nC5, the reaction order with respect to hydrogen varies between -0.652 and -0.620, and with respect to nC5 it varies between 0.336 and 0.339. The apparent activation energies were found to be 110-111 kJ/mol for nC7, 120-122 kJ/mol for nC6, and 145-148 kJ/mol for nC5. The study highlights the importance of hydroisomerization in octane upgrading and environmental protection, promoting the efficiency of automotive motors.

This study explores the hydrogenation of D-glucose to D-mannitol using Raney nickel as a catalyst. The effects of reaction time (15-115 min), reaction temperature (15-65°C), and catalyst to D-glucose ratio (3-11%) on the yield of D-mannitol were investigated. The Box-Wilson experimental design method was employed to establish relationships between these variables and the yield of D-mannitol. The results indicate that the reaction time had the most significant impact on the yield. Optimal conditions were determined to be 115 min reaction time, 50°C reaction temperature, and 3% catalyst to D-glucose ratio, resulting in a 14.01% yield of D-mannitol, 81.34% yield of D-sorbitol, and 94.9% conversion of D-glucose. D-Mannitol with 99.7% purity was obtained after separating it from D-sorbitol using fractional crystallization.

This paper presents a developed modified One Sampling Ahead Preview (OSAP) controller with repetitive control action for single-phase voltage source PWM inverters used in Uninterruptible Power Supply (UPS) systems. The proposed technique minimizes plant modeling errors resulting from simplifications made to obtain a linear discrete-time plant model. Additionally, the repetitive control action reduces steady-state errors and periodic distortions caused by nonlinear cyclic loads, thereby lowering Total Harmonic Distortion (THD). The technique utilizes a switching frequency greater than the sampling frequency, allowing implementation on a low-speed microcontroller. Simulation results verify the performance of the proposed approach under different load conditions, demonstrating its effectiveness in improving UPS system performance.

This paper aims to determine the optimal locations for placing generating plants in the Iraqi National Super Grid to achieve minimum total losses in the system. A MATLAB package was developed to allocate the optimal placement of generating sets, calculate active and reactive power for these generators, and determine the effect of varying generator output on loss reduction. The study demonstrates how proper placement of generation units can reduce losses, free up transmission capacity, and reduce equipment stress. The results provide valuable insights into improving system efficiency and reducing losses in the Iraqi Super Grid Network.

This study investigates the reclamation and reuse of textile dyehouse wastewater using the electrocoagulation process. The research focuses on the removal of reactive dyes (para red) and disperse dyes (M-5R200%) from wastewater. The effects of various parameters, including the nature of the anode (aluminum or iron), current density, initial pH, stirring rate, and dye concentration, on the removal efficiency were tested. Experimental results showed that aluminum anodes were more effective for disperse dyes, while iron anodes were better for reactive dyes. The study demonstrates that electrocoagulation is a promising method for treating textile dyehouse wastewater, significantly reducing dye concentrations and improving water quality for reuse.

This paper investigates the water quality of Al-Hammar Marsh in southern Iraq by analyzing water samples from various sites within the marsh. The study examines the variation of key water quality parameters, including Biochemical Oxygen Demand (BOD), Dissolved Oxygen (DO), Total Dissolved Solids (TDS), Electrical Conductivity (EC), Total Suspended Solids (TSS), Magnesium (Mg), and Sulphates (SO4), with respect to the distance along the marsh. The results indicate that while DO concentrations remain within acceptable ranges for drinking and agricultural use, high concentrations of TDS, EC, and Mg were observed at the beginning and end of the marsh. The study highlights the importance of monitoring and managing water quality to ensure the sustainability of marsh ecosystems.

This paper explores the differences between various Pulse Width Modulation (PWM) strategies for inverter-fed induction motors. The study compares the performance of sine PWM, space-vector PWM, and other advanced modulation techniques in terms of harmonic distortion, DC bus voltage utilization, and output line voltage quality. Using MATLAB simulations, the paper analyzes the effectiveness of these strategies in reducing harmonic content and improving motor performance. The results demonstrate that advanced PWM techniques can significantly enhance the efficiency and control of inverter-fed induction motors compared to traditional methods.

This paper presents a theoretical analysis of the South Baghdad and Dura power plants using the entropy method based on the second law of thermodynamics. The analysis focuses on calculating the irreversibility coefficient or lost work for each main block of the power plant, including the boiler, turbine, condenser, feed water heater, and pumps1. The overall irreversibility and thermal efficiency of the plant are then determined. The results are compared with previous analyses using the exergy method, showing that both methods yield approximately the same results1. The entropy method is highlighted for its simplicity and direct relationship between component losses and overall plant efficiency.

This paper investigates the airflow characteristics between two sets of wings representing a wing and a tail using a low-order panel method. The method employs constant source and doublet singularities with Dirichlet boundary conditions on the body surfaces. The study examines the effects of distance and setting angle changes of the tail on the airflow characteristics. The results, obtained from a FORTRAN program, show good agreement with published data, validating the method's accuracy. The findings suggest that the panel method can be a useful tool for designing and controlling aircraft stability by predicting interference effects between the wing and tail.

This paper reviews the improvement of technical operations in drinking water systems for water supply stations. It highlights the strategic role of water in the development of facilities and the importance of managing water resources effectively. The study identifies potential hazards and introduces control points to minimize these risks, ensuring better control over drinking water quality. The paper emphasizes the need for a new approach to water quality control based on preventive measures rather than reactive end-product testing. A Water Safety Plan (WSP) is proposed for risk assessment and management throughout the water cycle, from catchments to consumption. The implementation of this plan has led to a greater understanding of water quality control and improvements in technical operations and performance.

This study investigates the convective air drying of a single sweet potato sample, modeled as an ellipsoid with dimensions 40mm in length and 20mm in thickness. The research examines the heat and mass transfer processes occurring between the sample surface and its drying environment, as well as unsteady heat conduction and moisture diffusion within the sample without phase change. The numerical solution of mass and energy conservation equations was employed using the finite difference technique and body-fitted coordinate system with grid generation techniques. Empirical correlations were used to determine product properties and study the effects of various factors on the drying process. Results showed that product temperature increased and moisture content decreased over time, with higher air velocity leading to increased heat transfer coefficients and accelerated drying. The numerical results were validated against experimental data, showing good agreement.

This paper presents an experimental and finite element investigation on the load-slip behavior of composite steel-concrete column segments using various shear connectors. Twelve composite prototypes with different shear connectors were fabricated and subjected to push-out tests to measure slip values at incremental loads until failure. A nonlinear three-dimensional finite element analysis was conducted using the ANSYS program to predict load-slip relationships, equivalent stress distributions, and concrete cracking patterns. The study found that headed studs provided the highest slip resistance and ultimate load compared to channel and L-shaped studs. The results from both experimental and theoretical analyses showed good agreement, validating the accuracy of the finite element model.