Algerian Journal of Engineering and Technology

Celebrating Five Years of Scientific Excellence and Innovation

Abdelkrim Rebiai — 2025-08-01

Five years ago, a bold scientific vision took shape: to establish an Algerian platform dedicated to open access, peer-reviewed research and innovation in engineering and technology. This vision gave birth to the Algerian Journal of Engineering and Technology (AJET), a journal founded by a dedicated group of professors and researchers committed to promoting a culture of rigorous and ethical scholarly publishing across the Arab world beginning in Algeria, with an eye toward global impact.

LQR Control of a Flexible Satellite with Movable Mass Actuation

Jalal Eddine Benmansour — 2025-07-24

This paper addresses the challenging problem of optimal control for a flexible satellite equipped with a movable mass actuator. The dynamics of the satellite system include both rigid body rotations and elastic vibrations due to flexible appendages, which are modelled using second-order differential equations. The primary control input is generated by the strategic movement of an internal mass, which simultaneously produces torques for attitude stabilization and mitigates vibrational energy in the flexible modes. To achieve a delicate balance between minimizing state deviation and control effort, An optimal Linear Quadratic Regulator (LQR) strategy is implemented and its performance is compared with that of a conventional PD controller. The stability of the closed-loop system is theoretically established using the Lyapunov theory. Numerical simulations validate the proposed approach, demonstrating its effectiveness in minimizing flexible mode excitation and maintaining satellite attitude.

Devulcanizing Algerian End-of-life Tire Rubber for Rubber Sustainability and Rubber Product Circular Economy, in Algeria

Benabdallah Chouchaoui — 2025-07-24

Managing end-of-life tires (ELTs) remains a persistent global challenge for the transportation sector. Once discarded due to wear or irreparable damage, scrap tires pose severe environmental and health hazards. Although various disposal methods have been developed including landfilling, incineration, and crumb rubber production most are unsustainable and environmentally harmful. The vulcanization process, which transforms raw rubber into durable tire material, significantly hinders recycling efforts. However, recent technological advances offer promising solutions. In Algeria, over 6.2 million registered vehicles in 2020 generate more than six million scrap tires annually, with numbers expected to grow rapidly due to increasing vehicle ownership, shorter tire lifespans, and expanding electric and heavy-vehicle fleets. Without proper management, this waste will accumulate dramatically, exacerbating environmental degradation. Windsor Industrial Development Laboratory has developed an innovative devulcanization technology under the EcoCa™ brand, capable of reversing the vulcanization process effectively transforming used tire rubber back into a reusable form. This breakthrough enables the manufacturing of high-quality engineered rubber products. As a first application, the laboratory has successfully produced and tested passenger vehicle parking blocks made entirely from devulcanized rubber. The proposed four-step approach includes: i. Rubber recovery from scrap tires, ii. Devulcanization of the recovered rybber, iii. Compounding the devulcanized rubber, and iv. Manufacturing green products from recycled rubber. This technology offers multiple benefits: addressing environmental pollution, promoting rubber sustainability and circular economy, conserving natural resources, reducing energy consumption and greenhouse gas emissions, creating jobs, and building local technical expertise in Algeria. Windsor’s laboratory seeks industrial and academic partners in Algeria to establish a sustainable local recycling chain and support zero-waste manufacturing practices in the Rubber Industry.

Impact of Nanoparticles on Clay Sedimentation in Liquids

Naomi Ogolo — 2025-07-08

Clay sedimentation in colloids is a natural phenomenon that can be accelerated or retarded with additives. This is important in drilling operations where clay suspension in drilling muds is desired for effective functionality. Current studies have indicated that nanoparticles can improve rheological properties of drilling fluids but not much is known about their impact on clay sedimentation. Hence, this work investigates the effect of eight kinds of nanoparticles on clay sedimentation in the absence and presence of crude oil. A small fraction of these nanoparticles were dispersed in distilled water, brine of 30g/l salinity, ethanol and diesel containing clays, and the volume of settled particles under gravity were plotted against time. Linear graphs and parabolic shaped graphs within the short periods of observation indicate slow and accelerated sedimentations respectively. Results show that aluminum oxide and zinc oxide nanoparticles speed up clay sedimentation while nanoparticles of magnesium, zirconium, nickel, iron, tin and silicon oxides retard clay sedimentation rate in liquids, rendering these six kinds of nanoparticles potential clay stabilizers. In the absence of nanoparticles it was observed that clay sedimentation in water is slower than in ethanol and diesel and the presence of crude oil further slows down sedimentation. But in the presence of nanoparticles, the effect of crude oil on clay sedimentation is inconclusive, necessitating further studies.

Incorporation of Recycled Glass-Derived Powders For Manufacturing High- Performance Fiber-Reinforced Concrete

Oussama Douidi — 2025-07-07

Concrete, as the most widely used material in the construction industry, plays a crucial role in modern infrastructure. However, its production is a major contributor to environmental challenges, particularly due to the high carbon footprint of cement manufacturing. To address this issue, researchers are exploring sustainable alternatives, including the use of supplementary cementitious materials SCMs to partially replace cement while maintaining or enhancing concrete performance. This study investigates the feasibility of incorporating recycled glass derived powders namely, glass powder and cullet powder as partial cement replacements in high-performance concrete HPC manufacturing. The research evaluates their effects on key properties such as workability, setting time, mechanical strength, and durability, with replacement levels of up to 25%, as suggested from the literature. Preliminary experimental results indicate that while these materials influence fresh and hardened concrete properties, their use remains within acceptable engineering limits. While this approach seems promising to mitigating the environmental impact of cement production is the incorporation of sustainable supplementary cementitious materials to reduce cement consumption, optimizing the dosage is crucial to maintaining desirable properties. The findings of this study highlight the potential of recycled glass as an eco-friendly SCM, contributing to reducing the environmental impact of concrete production while promoting circular economy principles in the construction industry.