Kerbala Journal for Engineering Sciences

Soil stabilization has obtained significant attention to overcome challenges associated with weak soils. These efforts focus on improving soil properties, achieving economic benefits, and reducing environmental impacts. This study aims to evaluate the efficiency of using waste or by-product materials to improve the characteristics of subbase layers through chemical stabilization, with a particular focus on reducing construction costs and enhancing structural performance. The methodology included the use of the Cement Kiln Dust (CKD) and ordinary Portland cement (OPC) as chemical stabilizers for two types of subbase materials(Type B and Type C). The percentage of stabilizers for each mixture was 7% by dry weight of subbase; three stabilizer combinations were used: 100% OPC, 100% CKD, and a 50/50 blend of OPC and CKD. Laboratory tests were conducted, including sieve analysis, modified Proctor, California Bearing Ratio , Atterberg limits, and unconfined compressive strength tests to assess the properties of the stabilized soils. The results showed that a mixture of OPC and CKD in equal proportions significantly enhanced the compressive strength of the subbase materials,performance was improved and the required thickness of pavement layers can be decreased, leading to a significant decrease in overall construction cost.

Usually, water intakes are used to divert water from the primary canal or river to the tertiary canals and turbine systems. In cases when the flow is being separated at the branch channel\'s inlet, the flow structure in this area is more intricate than in other parts of the network. For the most part, intakes are built at right angles, which creates a sizable separation zone at the entrance of the subchannel and decreases flow discharge. In order to minimize the separation zone\'s dimensions, the intake should be positioned at the best possible angle. A numerical study was run in a rectangular channel with a side channel branching off of it to determine the optimal intake angle. To achieved this study, eleven intakes were installed on one side of the main channel at varying angles of 15, 30, 45, 60, 75, 90, 105, 120, 135, 150 and 165 degrees to find the optimum intake position. Additionally, a unique method for estimating the separation zone\'s dimensions utilizing an advanced microcomputing modeling approach called Gene Expression Programming (GEP) has been proposed as a result of the study\'s findings. The outcomes of the numerical simulation were then utilize to make a compare between the GEP model and the nonlinear regression model (NLR). As a comparison, high R values and small RMSE and MAE indicate that the empirical formula derived using the GEP program is superior to the NLR formula (R2=0.903, RMSE=0.109, and MAE=0.092).

This research investigates the potential of microalgae as a sustainable resource for bioenergy production using a microbial fuel cell (MFC) technology. It explores the general taxonomy and characteristics of algae, outlines the different generations of biofuels, and highlights the benefits and limitations of algae-derived biofuels. Particular emphasis is placed on integrating bio-electrochemical systems that simultaneously treat wastewater and generate electricity. The study demonstrates that utilizing algae in MFCs not only supports organic biomass production but also enhances nitrogen recovery and energy efficiency. Through experimental trials with various electrode modifications, the research confirms that algal biomass can effectively function as both a biofuel substrate and a sustainable energy solution. These findings propose a closed-loop, self-sufficient energy system with
minimal environmental impact, offering a viable alternative to fossil fuels.