Algerian Journal of Engineering and Technology

Towards hybridizing and intensifying electrochemical disinfection techniques

2024-07-12T09:42:42+00:00

Halting 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.

Electrochemical Disinfection Technology: Highlighting Advances and Outlooks

2024-07-12T20:53:14+00:00

Exciting 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.

Non-destructive multielement analysis of airborne particles by instrumental neutron activation analysis

2024-03-08T22:35:34+00:00

Instrumental neutron activation analysis (INAA) was used for the determination of the elemental composition of aerosol samples. Two samples of air of approximately 20 m³ each one were collected of the atmosphere around the Es-Salam research reactor site in Algeria. The irradiation of the samples and reference materials was carried out during 30 s for the elements of short half-life and 06 h for the elements of medium and long half-life with a thermal neutrons flux of 1.12 10¹³ and 6.88 10¹³ n/cm²s respectively. Ge(Hp) g-spectrometry made it possible to determine fifteen elements (Al, Cl, Mn, Ca, Cd, Br, La, Fe, Nd, Ce, Hg, Cr, Hf, Sb and Zn). The obtained results for the used reference materials almost perfectly match its certified values (Z_score<2).

Nonlinear adaptive control law design using TSMC for nuclear reactor in load following operation

2024-07-10T11:29:13+00:00

The 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.

GaAs electrical-properties enhancement by neutron transmutation doping

2024-07-13T09:44:01+00:00

This 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.

Experimental investigation and artificial intelligence modeling of stability of Agbabu Bitumen Emulsion using green-based surfactant

2024-07-14T09:55:04+00:00

One of the challenges that affected the optimal utilization of 42.47 billion tons of natural bitumen deposit in Nigeria is its high viscosity and high pumping cost in current state. This research investigated the possibility of reducing viscosity of Agbabu Bitumen (AB) through formation of emulsion using plant sourced surfactant solution. AB Emulsion (ABE) was prepared by homogenizing 60 vol. % of bitumen and 40 vol. % of water in the presence of surfactant solution extracted from Sanya root bark (surfactant solution was varied with respect to the volume of aqueous phase). Effect of increase in volume of extract, pH and salinity of extract was tested on the stability of the prepared emulsion. Emulsification Stability Index (ESI) was computed for all ABE prepared. Viscosity, pour, flash and fire point were determined for the emulsion formed while further analysis were conducted on the emulsion using Scanning Electron Microscope (SEM), Energy Dispersive X-ray (EDX) and Fourier Transform Infrared (FTIR) spectroscopy. The surfactant solution extracted ABE prepared from AB and water which was enhanced in alkaline solution, a 64% reduction in viscosity was recorded in emulsion prepared, and the pour point of emulsion drastically reduced when compared with that of AB.

Adaptive Nano Satellite Attitude Control Design under Multiplicative Actuator Uncertainties

2024-07-14T12:27:03+00:00

The utilization of nanosatellites in space missions has sparked significant interest owing to their compact size and relatively economical development, launch, and operational expenses in comparison to larger satellites. This cost-effectiveness facilitates more frequent launches and the capability to replace or upgrade satellites with greater frequency. The stability of nanosatellites is paramount for their successful operation in space, necessitating designers and engineers to implement various measures to ensure the satellite maintains its orientation and position throughout its mission. In this paper, an adaptive control methodology relies on backstepping control theory is suggested to address the multiplicative faults in the actuators. Specifically, the control system's efficacy is demonstrated through numerical simulations for 3-axis stabilization. The outcomes reveal that the proposed control approach adeptly sustains the stability of the nanosatellites in the event of actuator failure, outperforming classical backstepping control.