Algerian Journal of Engineering and Technology (AJET)
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Nonlinear adaptive control law design using TSMC for nuclear reactor in load following operation
Get PDFThe load-following process plays a crucial role within nuclear reactors. However, various factors, including uncertainties, can lead to performance degradation in these reactors. To address this, we propose a novel approach using nonlinear adaptive-based terminal sliding mode control (TSMC). To that purpose, the reactor nonlinear model is transformed to normal form using the feedback linearization technique. Based on that model and using the backstepping approach, a nonlinear nominal control law is constructed, which is then mounted with the adaptive discontinuous control law designed by TSMC. Then, a control law for the entire closed-loop system is developed to offer not only local asymptotic stability, but also resilience against uncertainty. A nonlinear terminal integral sliding surface is defined to solve the problem of SMC singularity. The system's stability was investigated using Lyapunov synthesis. To test the performance of the designed control law, numerical simulations are performed. The simulation results demonstrate that the designed control rule permits load-following control in addition to being insensitive to uncertainty
Electrochemical Disinfection Technology: Highlighting Advances and Outlooks
Get PDFExciting findings have emerged from recent studies on using in situ electrochemical methods for water disinfection, demonstrating their effectiveness in deactivating microorganisms. However, significant precautions should be considered in future research to ensure a reliable drinking water supply. This viewpoint proposes strategies for evaluating the efficiency of disinfection processes, which will aid in advancing the readiness of this technology. Additionally, it explores the recent advancements in electrochemical disinfection (ED) techniques to avoid the generation of harmful disinfection by-products (DBPs) and examines how water composition affects treatment outcomes. Further research is needed to explore alternative materials and establish optimal operating parameters to avert DBP production. The effectiveness of hybrid and sequential disinfection methods depends on various factors, and small-scale devices powered by renewable energy sources present a significant challenge. The extensive use of chlorine conducted to the emergence of chlorine-resistant bacteria (CRB), threatening public health. The extensive use of chlorine has induced the emergence of chlorine-resistant bacteria (CRB) that threaten public health. Nanowire-assisted electroporation (EP) demonstrates remarkable stability when operating in complex water matrices. EP/Cl2 effectively treats CRB in raw water, highlighting its potential use in real water matrices. Bacteria's vulnerability to RSs is well-documented, as their exposure can destroy proteins, DNA, and lipid membranes, ultimately causing cell demise. This characteristic makes the electrochemical production of RSs a highly appealing method for eliminating microorganisms during water treatment. It is crucial to prioritize expanding hybrid artificial intelligence (AI) technologies that could wholly employ the unique features of numerous AI technologies and deliver enhanced ED efficiency
GaAs electrical-properties enhancement by neutron transmutation doping
Get PDFThis study investigates the potential of neutron transmutation doping (NTD) for enhancing the electrical uniformity of gallium arsenide (GaAs) wafers used in photovoltaic cells. Uniformity is crucial for improving solar cell efficiency, which is a key objective in solar power engineering. We employ the SCALE6.1 code to simulate the impact of NTD on the Radial Resistivity Gradient (RRG) within GaAs wafers for various neutron fluence values.
The results demonstrate a clear decrease in RRG with increasing neutron fluence. Notably, acceptable RRG values (below 5%) are achievable for both high (25 Ω.cm) and low (5 Ω.cm) initial resistivity GaAs wafers with moderate neutron fluence levels (7.25x1014 n/cm² and 3.63x1015 n/cm², respectively). This suggests that NTD can effectively improve the electrical properties of GaAs, leading to potentially higher solar cell efficiency
Towards hybridizing and intensifying electrochemical disinfection techniques
Get PDFHalting the transmission of waterborne diseases relies heavily on disinfection, a crucial barrier against pathogenic microorganisms. Electrochemical disinfection (ED) has emerged as a widely studied and implemented approach for effectively neutralizing these harmful microorganisms in water and wastewater. This is primarily due to ED's simplicity, efficiency, and environmentally friendly nature. This review provides a concise overview of ED's fundamental mechanisms and systematically examines the targeted species. Furthermore, we comprehensively explore the explore the actual employment of ED in dealing with water and wastewater. Lastly, we discuss the potential for combining ED with other technologies and synergies, laying the groundwork for future engineering advancements. The literature primarily focuses on various ED methods for eliminating pathogens. Still, there is limited understanding of how process variables and reactor design impact the effectiveness of pathogen kills. The microbial killing mechanisms of ED, including the role of free radicals and the electric field (EF), are inherently harmful to microorganisms. Additionally, other mechanisms have been proposed to explain the timeframes for implementing ED in different applications. The processes involved in ED can be categorized into four pathways. The first pathway involves oxidative stress and cell death caused by the production of oxidants. The second pathway is the cell membranes' irreparable permeabilization due to the used EF. The third pathway is the electrooxidation of critical cellular components when exposed to electric current or induced EFs. Lastly, the fourth pathway is the electrosorption of negatively charged bacteria onto the anode, pursued by a direct electron transfer reaction. The coming exploration must concentrate on comprehending the impact of EF on ED and implementing safe multi-hurdle methods such as distillation, plasma discharge, nanotechnologies, and membrane processes in industrial settings. Granular activated carbon is recommended as a post-treatment method to reduce the concentrations of disinfection by-products (DBPs). Adsorptive techniques and membrane processes remain promising research areas due to their comparatively small prices and simplicity of application. Further investigations into improving electrochemical reactors and optimizing electrolysis conditions are necessary. Integrating the ED process with different treatment methods guarantees improved disinfection effectiveness, reduced power use, and minimized DBPs. This review encourages combining more than two processes simultaneously or consecutively for better efficiency
A Design and fabrication of an angle of repose apparatus for granular material analysis
No full textThe angle of repose (AOR) plays a crucial role in analyzing the flowability of granular materials, which are widely used in fields such as agriculture, pharmaceuticals, and civil engineering. This study outlines designing and constructing an affordable, user-friendly Apparatus for accurate AOR measurement. Built for both laboratory and field applications, the Apparatus was made from materials that are easily accessible and include an adjustable funnel, a central column, and a sturdy base to ensure consistent and precise measurements. Experimental tests using agricultural materials such as rice, beans, wheat, and millet yielded reliable results with low standard deviations. A paired t-test indicated significant statistical differences between the newly designed Apparatus and conventional methods (t-statistic of -2.98, p-value of 0.015), though these differences fell within an acceptable experimental range of ±0.5°. The mean difference of -0.26° and a 95% confidence interval of [-0.43°, -0.09°] illustrate a slight downward bias in the Apparatus while confirming its reliability and accuracy. This research provides a practical solution for measuring AOR, especially in resource-constrained environments, and suggests potential enhancements, like incorporating digital sensors for greater precision and changeable orifice opening sizes for the funnel ranging from 10 mm to 22 mm
Comparative Study of Biogas Yield from Animal Manure in Barn and Farm
Get PDF To improve the biogas yield from animal manure must be taken into consideration the quality of manure. It is clear that the difference in the method of pasture has an important impact on biogas production. The study aims to compare the amount of biogas produced from manure animals in barns (closed pastures) and animals in farms (open pastures). The study included different types of manure cows, sheep, and poultry. Experiments were performed in a 2 L plastic bottle digester in a water bath at a 37°C mesophilic range. The proportion of the mixture of animal manure and water used was 1:1 during the 12-day hydraulic retention time (HRT). The gas produced was measured by the volumetric water replacement method. The results showed that the barn manure had higher biogas production than the farm manure approximately 3 times because their feed had concentrated nutritional supplements
Consolidation and collapse behavior of silty soil reinforced with plastic water bottles wastes
Get PDFThis research paper has focused on the influence of plastic waste materials (water bottles) on the consolidation and collapse behavior of silty soil. The silty soil was randomly reinforced with various fiber content (0.5, 1.0 and 1.5% of the dry weight of soil) having various lengths of 10, 20 and 30 mm. The soil samples were prepared at the maximum dry unit weight and the optimum moisture content of unreinforced soil, (natural soil) using standard compaction efforts. The variation in the compaction, collapse and consolidation characteristics of unreinforced and reinforced soil samples were evaluated. The test results indicated that there was a slight reduction in both the maximum dry unit weight and the optimum moisture content of soil samples with fiber addition. The collapse index increased with increasing fiber content, while the fiber length enhance the collapsibility of silty soil. Further, the compression index of reinforced soil samples followed the same trend as the collapse index
Investigation of the microbial effect of wastewater on concrete performance
Get PDFConcrete subjected to wastewater environment deteriorates faster than its counterpart in an ordinary environment. The investigation also showed that the deterioration effect could also be counteracted using bacteria. This study investigated the deterioration and healing effects of bacteria isolated from wastewater on concrete properties like weight loss, compressive strength, modulus of elasticity and SEM analysis. The result at 28 days of curing showed that the greatest reduction in weight (4.2%) and compressive strength (16.69%) compared with control was observed in concrete inoculated with S. epidermidis; while the least decrease in weight (0.8%) and an increase in compressive strength (1.79%) was observed with the concrete cast with potable water and cured in nutrient broth medium. The healing effect of B. subtilis on the concrete was also considered and analyzed, the result showed that B. subtilis improved the strength of the concrete exposed to S. epidermidis. Scanning Electron Microscopy analysis showed that an increase in the pores within the concrete leads to a reduction in compressive strength
Contribution to characterization of the Zinc retention by marl collected from the aquifer substratum
Get PDFTwo samples (S20 and S6) of marl are collected from aquifer substratum of the watershed of Wadi El-Ghoula in order to make a comparative study to remove Zinc from solution. The DRX analysis indicate five phases Montmorillonite, Illite, Kaolinite, Calcite and Quartz X-Fluorescence shows the predominance of silica, alumina and lime. In FTIR analysis, all bands are identified for S20, S6. The specific surface area for S20 and S6 are equal respectively to 21.6206 m2/g and 24.6445 m2/g and our materials have a meso-porous character. The retention capacity at equilibrium for S20 and S6 are equal respectively to 9.94 (mg/g) and 9.87 (mg/g). Liquid film diffusion and intraparticle diffusion models control simultaneously the process of adsorption of zinc in Marl. Non-linear treatment gives Langmuir and Temkin as best model for S20 and Freundlich for S6. Radlish-Peterson is the best model for S20 but for S6 the best model is given simultaneously by Sips and Radlish-Peterson. The values of AIC and AICc give a good opportunity to separate between used isotherms models
Enhanced approach for CDF quantification in Seismic Probabilistic Safety Assessment of a Research Reactor
Get PDFIn Probabilistic Safety Analysis (PSA) applications, it is common practice to employ approximations with the expectation or assumption of a small overestimation in the quantification of the Core Damage Frequency (CDF). The overestimation of the CDF depends on the Minimal Cut Sets (MCS) structures and event probabilities but the amount of conservatism is generally unknown. Hence, when dealing with large and non-coherent fault trees, conventional approaches to model dependencies in event trees analysis using coherent approximations are shown to be inaccurate. The limitation of the techniques in terms of accuracy of the solutions becomes apparent. For instance, the quantification methods using Rare Event (REA) and Min Cut Upper Bound (MCUB) approximations valid in internal event PSA may result in excessively conservative results in Seismic PSA. Therefore, in order to calculate the accurate top event probability from a fault tree rather than improving the direct probability calculation from cut sets, the Binary Decision Diagram (BDD) is introduced for more exact quantification. BDD development highlights the effort to reduce the conservatism caused by RAE and MCUB computations. The analysis carried out in this work, within the Seismic Probabilistic Safety Assessment (SPSA) of a nuclear Research Reactor (RR) case study using BDD framework shows that the approach is feasible and effective in evaluating the seismic risk of core damage and provide reasonable assurance that related decisions on real-time risk status can be taken robustly and with confidence