Wasit Journal of Engineering Sciences

The throughput growth of the coming wireless communication schemes requires the deployment of more base stations at a lower power use. We were inspired by the newly recommended intelligent reconfigurable surface technique (IRS) to address this issue. Specifically, this article mainly concerns the joint pre-coding scheme design challenge concerning improving the output at the base station (or the access point) and IRS stages. An iteration strategy called MMSE-MP has been developed, procedures a minimum mean squared error pre-coder (MMSE) approach for the Digital-BF and the Matching Pursuit (sparse approximation algorithm) for the Analog pre-coding, to cope with this complex challenge. For the reflecting element phase shift matrix the algorithm uses the arrival/departure angles of the LoS rays at the IRS elements. Basically, the joint problem of optimizing the analog and the digital pre-coder was transformed into a one-variable matrix reconstruction, i.e., sparsity-constrained signal-recovery optimization. The simulation outcome confirms that there is nearly 66.5% spectral enhancement if comparing with the classic network without IRS for a certain power scenario of the scheme.

The rapid growth of Open Radio Access Networks (Open RAN) necessitates innovative resource management systems to address security and decentralization challenges. This study proposes the use of blockchain technology for enhancing the security, privacy, and decentralized decision-making in Open RAN cellular networks. The research focuses on secure communication between O-DU (Distributed Units) and O-CU (Centralized Units) using blockchain technology, along with smart contracts for O-DU to O-CU mapping, thereby ensuring data integrity and authenticity in resource management transactions. By leveraging a blockchain network and consensus methods, this study aims to validate resource management transactions securely and transparently. Smart contracts enforce resource management rules and adapt O-DU to O-CU mapping based on real-time network conditions. The experimental framework simulates an Open RAN environment with multiple O-DUs and O-CUs under dynamic network conditions and traffic demands, rigorously testing blockchain's security in O-DU to O-CU transactions. This study demonstrates that the proposed solution can improve transaction security, trust, transparency, smart contract automation, reduce resource allocation delay, and increase flexibility to dynamic network circumstances. The findings contribute to the ongoing efforts in enhancing the efficiency, security, and flexibility of 5G and beyond.

Brushless DC (BLDC) motors are used in various applications, including industrial, automotive, aerospace, and computers, due to their many benefits. Still, it has some drawbacks, like its cogging torque and torque ripple. A three-phase, 1500-watt, four-pole, inner rotor brushless DC motor was modeled and examined using finite element analysis (FEA) based on Maxwell-2D software to analyze cogging torque at no excitation state and torque ripple at full load condition. Design parameters, including magnet thickness, embrace factor, magnet offset, and initial rotor position, were employed to mitigate their effects on cogging torque and torque ripple. The detailed obtained results will guide BLDC motor designers to select proper values of magnet thickness, embrace factor, offset, and initial rotor position without needing to test many costly produced prototype motors.

As a viable solution for the treatment and recycling of sewage from residential areas, this research presents membrane bioreactors (MBRs) systems, both immersed and side-stream. These systems are offered as viable options. This study's objective is to analyse the overall performance of each membrane bioreactor in terms of its capacity to meet water reuse requirements. This will be accomplished with the assistance of water quality indices such as total suspended solids (TSS), biological oxygen demand (BOD), and chemical oxygen demand (COD). It is obvious from the data that the MBR system is capable of producing permeate water of a high quality and that the MBR technology is efficient in reducing total suspended solids (TSS). COD and BOD rejection rates in the submerged MBR were, on average, 92.76% and 94.46%, respectively. This was the case. Comparatively, the percentages of COD and BOD that were rejected in the side-stream MBR were 87.54 percent and 88.98 percent, respectively. It has been discovered through the examination of COD and BOD that the removal of the submerged MBR system is preferable to the removal of the side-stream MBR system.

Author Biography
Prof. Dr. Hatem Asal Gzar, Civil engineering Department, Wasit University, Wasit, Iraq.
Hatem Asal Gzar. Civil Engineering Department, Wasit University, Wasit, Iraq.

Many locations worldwide are encountering significant obstacles to achieving economic and social sustainability due to the increasing disparity between water availability and demand resulting from population expansion. Therefore, many countries are looking for alternative water sources to increase their water supply. Water reuse has become a practical and effective method for addressing water scarcity. A systematic review and meta-analysis of water reuse are necessary to provide guidance for future studies on the impact of water reuse and to assist managers in optimizing the usage of water reuse technology for improving workplace and organizational results. This is the initial systematic review to investigate the correlation between public acceptance and water reuse. This systematic research aims to provide a comprehensive analysis and summary of public acceptance regarding water reuse surveys. The study compiled data from 85 original research papers published between 2018 and August 1, 2023. The information included details such as keywords, Geographic location, Cloud of words co-occurrence, sample size, publication peer years, published journals, and affiliations. In addition to this, it evaluated potential avenues for future research in this area and offered recommendations for enhancing the public\\\\\\\'s acceptance of water reuse.

Generally, The problem of sediments at the entrances to subsidiary channels is considered one of the most common problems for which water resources engineers seek to find appropriate solutions, as it causes significant damage to hydraulic installations, as the accumulation of these sediments in the canal rollers over time leads to the collapse of those channels, which results in many losses. In this study, a three-dimensional mathematical model was developed using the Ansys Fluent CFD program, and this model was matched with previous laboratory experiments, as this mathematical model showed clear accuracy and consistency. Work was done on changing the geometry of the sub-channel and studying the effect of changing the inclination of the sub-channel on reducing the amount of sediment entering the channel or not, since the channel used in this study is 2 m. Adjustments were made to the inclination of the canal in two different forms: The first is to make the first half (1 m) of the canal horizontal, and the inclination begins in the second half, at three different angles, namely 15, 30, and 45 degrees. The other form is to change the inclination along the total length of the sub-channel (2 m) with the same effect. Angles 15, 30 and 45. The results showed the ineffectiveness of changing the inclination of the sub-channel from the middle of the distance, while the results of changing the total inclination were different. It is possible that the slope angle of 45 is considered the best in terms of increasing the speed and clearly reducing the area of the separation zone and the erosion zone.

This study was conducted to quantify the physical and mechanical hazards in welding shops and assess the use of personal protective equipment (PPE) in these environments. The cross-sectional field survey took place in 10 welding shops selected by appropriate sampling methods from Kut city of Wasit Governorate, Iraq, and collected environmental measurements regarding temperature, humidity, and noise levels. All welders experienced hazardous levels of noise, humidity, and temperature. Electrical shock was experienced by 87.2% of welders, and 20.5% were exposed to fire. The temperature levels ranged between 38–41°C with 10–13% humidity. The heat index was a moderate 35–38° C in all welding shops, and the reported noise levels were unacceptably high. All of the work is manual labor. This assessment revealed that welders are regularly exposed to various mechanical and physical hazards and the use of PPE among them is very low, despite it being vital to their protection from hazards and prevention of accidents.

Photovoltaic (PV) systems can be used in a wide range of applications because of a significant drop in cost over the last ten years for PV modules. Because PV solar panels are low-cost and have a simple design that just requires sunshine to work, they can be used to power loads that are directly linked to PV panels. Because of this, it is a more alluring option for applications involving water heating.

In this work, experimental evaluation has been done for photovoltaic-direct-powered solar domestic hot water systems on 3/Jan./2024 a clear, sunny day. When evaluating performance, the value of power generated by PV panels is crucial. As solar radiation rises, its value rises as well. The PV heater tank's inside water temperature reached a maximum of 83.50 °C. A family of three members used 131 liters of water at a flow rate of 2 L/m. The maximum power delivered to the heating element was 1188 W, and the maximum power generated by PV panels was 1240 W. Based on the specifications of the 1500W heating element utilized, about 312W of electricity is lost during operation. Calculations revealed that the system's electrical efficiency was 22.3%. The system required 8.6 years of payback time to recoup its initial expenditure. Based on these results, it is advised to utilize a direct- connected photovoltaic water heater system (DPVWH) in cold weather because of its ease of use and efficiency, as it is a technology that operates during daylight hours.

The car cooling systems, was considered one of the most important parts which work in dissipated the heat is generating by engine of the car. This study used simulation of CFD to optimize the radiator thermal performance by changing the pipe material while maintaining the same cross-sectional area. By used water-Ethelyn-glycol mixture (50:50) as a hot fluid at flow rates of (12) and (24) litters/hour at different temperatures (85, 90, 95) oC, air was considered a cold fluid with different speeds, respectively (1.5, 2.5, 4.5, 5.5) m /s and its inlet temperature (35) oC . It was clear from the results that there was a significant convergence in heat transfer rates when replacing the pipe metal from copper to aluminium for the improved model compared to the basic model. They are approximately equal at some air velocity. with a small advantage for copper of approximately 5% in terms of heat transfer rate and overall heat transfer coefficient.

Heat exchangers with uniform heating ensure even heat distribution, improving heat transfer efficiency and lowering thermal stress. It contributes to increasing the effectiveness of solar energy conversion into thermal energy in solar collectors, improving system performance and sustainability. It is essential for enhancing performance in both home and industrial applications because of these advantages. An experimental investigation was conducted to study the natural convective flow between two isothermal concentric cylinders filled with porous media (silica sand) and equipped with annular fins attached to the inner cylinder. The fins varied in length (Hf = 3, 7, and 11 mm), and the radius ratios (Rr) between the cylinders were also considered during the study. This work examines and discusses the effects of independent characteristics, such as fin height (Hf), radius ratio (Rr), and Rayleigh number (Ra) from 10 to 500, on heat transfer outcomes. As the distance between the two cylinders expands, the average Nu remains relatively constant for low values of Ra. However, as Ra approaches 100, the average Nu increases. These values also rose when Rr decreased for the hot cylinder and vice versa for the cold cylinder. The average Nusselt number versus Ra was analyzed in graphical form to show the effect of the fin number on the average Nusselt number. The analysis includes a range of fin numbers. It is found that as the amount of fins increases from n = 12 to n = 23 and eventually to n = 45, there is a decrease in the average Nusselt number. The decrease in average Nusselt number can range from 19.2% to 26.6% for the same value of Ra.

Many techniques have been incorporated into the design of turbine blades in an attempt to improve their performance. Assessment is applied to investigate the flow behaviour around NACA 0012 with modifications (slotted and wave slotted airfoil) experimentally. An open subsonic wind tunnel with a test section of (30.5 ×30.5×60 cm) was employed to conduct the test. The work experiment investigated two modified models (slotted and hybrid slotted and wavy) then compared them to the normal blade model. A slotted blade NACA 0012 airfoil model with a slot width of 1.5 mm at 60% of the chord was employed in the current study. All blades exhibited stall between 10o to 12o angles of attack at various wind speeds (10, 15, 20, and 20 m/s). The normal blade showed an earlier stall at angle of attack at 10o. Additionally, the increase in wind speeds showed that the modified models did not exhibit better stall delay than the normal on then better performance than the normal model.

This work focuses on employing burned clay (FC) materials as a low-cost adsorbent to remove cadmium and lead ions from synthetic stormwater and to evaluate its performance and applicability as a supplementary component to remove Cadmium and Lead ions in an aqueous solution. The studies were carried out to look into the Cadmium and Leads' room-temperature adsorption isotherm and the effects of various variables. The primary adsorbate concentration, contact time, agitation speed, pH, and mass of the adsorbent have all been studied. According to the results, the optimal experimental conditions-pH=6, 0.45mg/l of Cadmium and 0.08 mg/L of Lead as adsorbate, 12 g of adsorbent, 250 rpm of agitation, and 2.0 hours of contact time -reduced Cadmium and Lead by 93 percent for fired clay. The experimental data were examined using the Langmuir and Frendlich isotherm models. The preferred model for Cadmium and Lead adsorption onto fired clay material, according to the results, was the Langmuir adsorption isotherm. This study clearly shows that fired clay particles can be employed as a low-cost adsorbent to take Cadmium and Lead out of water.

This study examines sustainability initiatives in urban renewal projects in the canter of the holy cities of Najaf and Karbala, two cities of historical and cultural importance to the Islamic world in general, and to the Shiite community in particular. The study aims to evaluate the current situation in the two cities, and emphasizes the different methods for preserving the heritage and enhancing public spaces in the cities of Najaf and Holy Karbala, which were shaped by their unique historical, cultural and urban features. Despite a shared commitment to protecting their historical heritage, these cities face challenges in integrating modern technology and engaging the community in environmental conservation efforts.

A questionnaire was conducted directed to experts to determine development priorities through seven main indicators of sustainability concepts and tested on the research case study. The results showed in the canter of the holy city of Karbala a clear preference for indicators of social integration and suitability of areas open to visitors (between the two holy shrines) with a clear weakness in indicators of preservation and provision of transportation. Public and community participation in development projects. While the results in the centre of the Holy City of Najaf showed a clear preference in maintenance, development, and transportation work for people with special needs, and delegations of visitors, this difference could be due to the nature of the spaces surrounding the Holy Shrine in the canter of the Holy Shrine of Najaf at the expense of open spaces for the residents of the region. The research recommends developing a plan that takes into account sustainability and aims to balance the needs of residents and visitors alike, with a focus on spatial and functional gradation to achieve sustainability requirements within the main research indicators.