Kerbala Journal for Engineering Sciences

The construction sector is considered an important part of improving the economy and enhance the development of the countries. Therefore, executing a construction project with the signed time in the contract is essential to fix the general plan. On this base, construction delay will obstruct the estimated plan end and start another project. This literature review studies the recent articles in Iraq ten year ago by exploring the methodologies and the most reasons of delay in construction projects in different cities such as, Baghdad and Najaf. This study analyzed 12 articles and search respective to the used method; delay causes and mitigation. The results were 31 causes of delay in construction projects were selected but the most reason of delay is financial problems by both contractor and owner which repeated five times in the study articles, however, political and management issues repeated four times in the articles. Study conclusions that financial and management represent the main cause of delay. To avoid the possible delay in completing construction project in Iraq, project owners should put suitable plan with suitable payments in project budget and selecting management plan to solve any possible problems, however, political issues cause delay in construction projects without any mitigation from both contractor and owner.

Access to potable water for the global population is gradually decreasing every day. Most human diseases are attributed to the use of contaminated or impure water sources. The need for water purification does not disrupt the ecosystem. Solar still is a water purification technology that produces ultra-pure distilled water without any harmful impact on the environment. Solar still systems provide sustainable solutions for fresh water production. There are various environmental and operational factors that are necessary to optimize the design of the still. Researchers have evaluated different designs to enhance the productivity of solar stills. The studies mentioned in this research paper demonstrated that the integration of a solar still with an exterior or internal solar condenser resulted in an effective and efficient productivity. This thorough inquiry seeks to show, depict and assess the condition of distinct solar stills together with various concentrator setups.

A comparative analysis of the performance of various types of inverters is presented in this paper to improve the operational efficiency of a wireless power transfer (WPT) system that is specifically designed for left ventricular assist devices (LVADs). Minimizing total harmonic distortion (THD) of the inverter's output can enhance the quality of the AC signal supplied to the WPT system and improve system efficacy. Three inverter topologies were designed: the H-bridge inverter, the multilayer inverter, and the Class-E inverter, at different distances of 30 mm, 50 mm, and 60 mm. Using the Class-E inverter in the WPT system achieves 63.3% overall performance with a THD of 2% at a distance of 60 mm, as indicated by the simulation results. While using the multilayer inverter exhibited moderate performance, reaching 50% efficiency and 24.5% THD, the H-bridge inverter accomplished 45% efficiency and 49.19% THD. The efficiency and quality of the transmitted power are improved by using the Class-E inverter in the WPT system compared to alternative varieties. Consequently, a Class E inverter can provide superior performance for particular types of wireless power transfer systems, particularly in biomedical applications.

The sewerage network is one of the main pillars of urban infrastructure. However, it faces increasing challenges due to the aging of its components, the rapid pace of urbanization, climate change, and high consumption rates. Rainwater runoff and seepage (RDII) are among the most significant problems negatively impacting the efficiency of these networks, contributing significantly to sewage overflows and their consequent serious environmental and health impacts. The current research focused on analyzing the sensitivity of the main sewerage pipeline in the center of Karbala, Iraq. This city of global religious and tourist importance receives millions of pilgrims annually in a short period of time, placing high pressure on the sewerage network. To achieve this, recorded discharge and rainfall data were analyzed using Sanitary Sewer Overflow Analysis and Planning (SSOAP), along with a comprehensive flow simulation using the Personal Computer Storm Water Management Model (PCSWMM) to evaluate the hydraulic performance of the pipeline under heavy rain conditions and identify potential areas of vulnerability. The analysis results showed that rainfall intensities ranging from 20 mm/h to 24 mm/h represent the upper limit of a pipe's capacity where the 25 mm/h rainfall signifies the failure threshold for the existing pipeline.

The sewerage network is one of the main pillars of urban infrastructure. However, it faces increasing challenges due to the aging of its components, the rapid pace of urbanization, climate change, and high consumption rates. Rainwater runoff and seepage (RDII) are among the most significant problems negatively impacting the efficiency of these networks, contributing significantly to sewage overflows and their consequent serious environmental and health impacts. The current research focused on analyzing the sensitivity of the main sewerage pipeline in the center of Karbala, Iraq. This city of global religious and tourist importance receives millions of pilgrims annually in a short period of time, placing high pressure on the sewerage network. To achieve this, recorded discharge and rainfall data were analyzed using Sanitary Sewer Overflow Analysis and Planning (SSOAP), along with a comprehensive flow simulation using the Personal Computer Storm Water Management Model (PCSWMM) to evaluate the hydraulic performance of the pipeline under heavy rain conditions and identify potential areas of vulnerability. The analysis results showed that rainfall intensities ranging from 20 mm/h to 24 mm/h represent the upper limit of a pipe's capacity where the 25 mm/h rainfall signifies the failure threshold for the existing pipeline.