Journal of Engineering & Technological Advances

DESIGN AND FABRICATION OF A PORTABLE DRILLING RIG FOR AGRICULTURAL IRRIGATION BOREHOLES

Rabiu Ahmad Abubakar — 2026-06-30

Access to affordable groundwater extraction technologies remains a major challenge in many rural, where conventional rotary drilling rigs are often impractical due to high cost, technical complexity, and intensive maintenance requirements. This study presents the design, fabrication, and experimental evaluation of a low-cost, mechanically simple, and locally manufacturable portable drilling rig intended for residential boreholes and small-scale agricultural irrigation. The rig was engineered to balance drilling performance with affordability by using readily available materials and straightforward mechanical components, enabling ease of replication, operation, and maintenance in resource-constrained settings. Experimental evaluations were conducted in sandy, clayey, loamy, and gravelly soils at varying rotational speeds, with penetration rate, torque, power consumption, and drilling efficiency recorded. The prototype achieved optimal performance in sandy formations, reaching a penetration rate of 18.3 cm/min, a torque of 45 Nm, and power consumption of 1.6 kW, while cohesive and coarse soils required higher torque and energy input. Comparative benchmarking against commercial systems Hydra-Drill MUD-2, LoneStar LS100, and PAT-301T showed that although the prototype exhibited lower penetration rates (0.95–1.25 m/hr versus 2.1–3.5 m/hr) and shallower depth capability (up to 22 m), it demonstrated superior energy efficiency (0.06–0.14 kWh/m compared with 0.14–0.33 kWh/m), enhanced portability, rapid setup, and significantly lower operational costs. Overall, the results indicate that the proposed system is a viable and sustainable solution for shallow to moderate borehole drilling. Future work will focus on hydraulic assistance, modular power integration, and sensor-based torque control to improve adaptability across diverse geological conditions.

A SYSTEMATIC LITERATURE REVIEW ON SERVICE-LIFE PREDICTION OF METAKAOLIN-MODIFIED CONCRETE UNDER FREEZE–THAW CONDITIONS

SHITONG YAN — 2026-06-30

Concrete infrastructure in saline cold-region environments is exposed to severe durability challenges. These challenges arise from the combined action of freeze–thaw cycling, salt crystallization, and sulfate-induced expansion, which accelerates material degradation. The utilization of metakaolin (MK) as a supplementary cementitious material has shown considerable promise for enhancing concrete performance under such aggressive conditions. This study provides a systematic synthesis of recent experimental studies concerning the behavior of MK-modified concrete exposed to freeze-thaw cycling, combined salt-frost action, and sulfate wet-dry cycles. A unified methodological framework is outlined, bringing together analyses of material properties, exposure conditions, degradation indicators, and microstructural development. Evidence reported across multiple studies indicates that MK effectively refines the pore structure, curtails the transport of moisture and deleterious ions, and reinforces the interfacial transition zone, thereby promoting greater stability of mechanical properties under cyclic deterioration. The performance of MK across different concrete systems is also examined, including ordinary Portland cement, recycled aggregate concrete, fiber-reinforced concrete, and compositions incorporating superabsorbent polymers for internal curing. Emerging predictive methodologies, such as Weibull statistical analysis, environmental factor models, and data-driven machine learning techniques, are evaluated for their potential in forecasting long-term behavior under composite saline-freeze environments. Based on quantitative studies, metakaolin effectively enhances concrete durability in saline-freeze and sulfate environments by refining the microstructure. The optimal 10% to 15% incorporation ratio maximizes service life. These findings clarify the performance of MK-modified concrete in cold regions and help link material modification with service-life prediction.

COMPARISON OF LSTM AND GRU IN TRAFFIC DENSITY PREDICTION USING HISTORICAL VISUAL DATA AND YOLOV5 DETECTION

Filda Angellia — 2026-06-30

The problem of traffic congestion in urban areas requires adaptive and data-based predictive solutions. This study aims to develop vehicle density detection and prediction patterns based on historical visual data by integrating YOLOv5 object detection algorithms and sequential neural network models, namely Long Short-Term Memory (LSTM) and Gated Recurrent Unit (GRU). The study also compared the effectiveness of LSTM and GRU in capturing vehicle movement patterns over time. LSTM can be implemented on long-term prediction accuracy by preserving more complex historical contexts, while GRU can be implemented for better training efficiency and processing time due to its simpler architecture. The dataset consists of 254 videos and 13,435 frames with an average VPS of 10.0. The GRU model obtained an MSE value of 5.81, lower than LSTM 6.05, indicating that the mean squared difference between the prediction and the actual value was smaller in the GRU. The RMSE value in the GRU is 2.41, also lower than the LSTM 2.46. The difference of about 0.05 points, although it seems small, still shows consistency that the GRU prediction error is lower. In MAE, the GRU has a value of 1.84, lower than the LSTM 1.89, which means that the mean absolute difference between the prediction and the actual value is smaller in the GRU. This research not only contributes to intelligent transportation systems but also opens up opportunities to develop traffic monitoring systems that are responsive to vehicle dimensions and traffic environment dynamics in real-time.

SYNTHESIS OF UCST-TYPE THERMORESPONSIVE POLY(ACRYLAMIDE-CO-ACRYLONITRILE) DOPED PVDF NANOFIBRE MEMBRANE

Abdelrahman Khalil — 2026-06-30

Ensuring access to clean and safe water requires the development of advanced membrane materials with tunable and adaptive surface properties. However, conventional polymeric membranes typically exhibit static physicochemical characteristics, limiting their ability to respond to changing operating conditions. In this study, a stimuli-responsive poly(vinylidene fluoride) (PVDF) nanofibre membrane was developed through the incorporation of a thermoresponsive copolymer, poly(acrylamide-co-acrylonitrile) (PAAm-co-AN), which exhibits upper critical solution temperature (UCST) behaviour. The PAAm-co-AN copolymer was synthesized in-house via free-radical copolymerization of acrylamide (AAm) and acrylonitrile (AN) at a 70:30 molar ratio and blended with PVDF at 0, 3, and 10 wt%. Electrospun membranes displayed uniform nanofibrous architectures with interconnected pore networks. Scanning electron microscopy (SEM) revealed systematic morphological evolution with increasing PAAm-co-AN content, transitioning from uniform smooth fibres in neat PVDF to slightly thicker fibres and a more interconnected nanofibrous network at higher copolymer loadings. Surface wettability measurements showed a significant reduction in water contact angle from approximately 90° for pure PVDF to 49° and 34° for membranes containing 3 and 10 wt% PAAm-co-AN, respectively, indicating enhanced hydrophilicity. Temperature-dependent behaviour was further examined using dynamic light scattering (DLS), which demonstrated a greater than 60% increase in hydrodynamic diameter at 60 °C compared to room temperature, attributed to strengthened hydrogen bonding and interpolymer complexation between PAAm amide groups and the PVDF backbone. Overall, the results confirm that incorporating PAAm-co-AN into PVDF nanofibre membranes enables temperature-responsive modulation of structural and surface properties, providing a promising material platform for the future development of smart membrane systems.

EXTRACTION OF NITROGEN COMPOUNDS FROM MODEL DIESEL USING IONIC LIQUIDS – A BRIEF COSMO-RS STUDY

Muhammad Zulhaziman Mat Salleh — 2026-06-30

The removal of nitrogen-containing aromatic compounds from diesel is critical for meeting stringent fuel quality and emissions standards. Conventional hydrodenitrogenation (HDN) has limitations in removing these contaminants, which prompted the exploration of alternative separation methods. This study focuses on the extractive denitrogenation of model diesel using ionic liquids (ILs), screened computationally via the Conductor-like Screening Model for Real Solvents (COSMO-RS). Eight ILs were initially evaluated for their ability to extract the non-basic aromatic nitrogen compound, pyrrole from a model diesel system consisting of hexadecane. Screening results identified 1-ethyl-3-methyl-imidazolium dicyanamide and 1-ethyl-3-methyl-pyridinium bromide as the most effective ILs based on selectivity and capacity respectively. These ILs were subsequently evaluated for the extraction of the basic nitrogen compound, pyridine. The performance of the selected ILs in extracting pyrrole and pyridine was compared with that of the conventional organic solvent dimethylformamide (DMF) using selectivity and capacity as key metrics. These results demonstrate that both ILs outperform DMF with its respective metrics. A final evaluation was conducted by analyzing the ternary liquid–liquid equilibrium (LLE) system. Ternary LLE analysis revealed negligible hexadecane content in the IL extract phase which implied minimal cross-contamination. In contrast, the DMF system showed significant solvent presence in the hexadecane-rich phase which confirmed notable cross-contamination. Overall, this work demonstrates the superiority of ILs over organic solvents such as DMF for extractive denitrogenation which supports a promising alternative for cleaner fuel production. The present study completes the computational screening of promising ILs using a highly reliable tool which could guide subsequent experimental works for users with limited computational resources.

ANALYSIS OF TWO SOLAR PROTON EVENTS DURING THE RISING PHASE OF SOLAR CYCLE 25 AND THEIR ASSOCIATED GEOMAGNETIC IMPACTS

Mahalakshmi K. — 2026-06-30

Two solar proton events (SPEs) that occurred on 25 February 2023 and 22 April 2023 during the rising phase of Solar Cycle 25 were associated with strong geomagnetic storms. These events were linked to HALO coronal mass ejections (CMEs) and M- or X-class solar flares. To understand their initiation and propagation, multiwavelength data from various space- and ground-based instruments were analysed. The results show that the CMEs generated shock waves as they moved through the interplanetary medium, producing geomagnetic storms with intensities greater than 100 nT near Earth. Differences in CME speed and direction affected the level of geomagnetic disturbance. These findings improve our understanding of how solar eruptions lead to space weather events and can help enhance future space weather prediction models.

REGIONAL CLUSTERING BASED ON THE FIFTEEN-MINUTE CITY (FMC) CONCEPT USING THE OPTICS METHOD

Marisa Premitasari — 2026-06-30

Rapid urbanization in Indonesia has intensified environmental degradation, social inequality, and uncontrolled urban sprawl, creating significant challenges for long-term urban sustainability. To address these issues, this study examines the application of the Fifteen Minutes City (FMC) concept as a framework for improving equitable access to essential services within a 15-minute walking distance. The objective is to evaluate whether a facility-based, data-driven spatial analysis can identify urban zones that align with FMC principles. Unlike traditional FMC approaches that incorporate housing or population density, this research adopts a facility-based interpretation, focusing solely on the distribution of public facilities and pedestrian ways. A total of 1,239 public facility points were retrieved from OpenStreetMap and compiled into a tabular FMC dataset. The methodological scope includes three stages: (1) pre-processing through the construction of a walking distance matrix to measure pedestrian accessibility between all facility points; (2) OPTICS clustering to identify spatial structures and service accessibility patterns; and (3) GIS-based visualization to map cluster outcomes and spatial variations across the Bandung Region and surrounding areas. The OPTICS model yielded a Silhouette Score of 0.688 and a Calinski–Harabasz Score of 1161.282, producing 33 clusters with 50.9% noise, indicating that meaningful spatial groupings can be detected despite the dispersed distribution of facilities. In conclusion, this study demonstrates the applicability of OPTICS clustering for examining the spatial distribution of urban services and evaluating their alignment with Fifteen-Minute City principles.

INVESTIGATION OF BIODIESEL PROPERTIES OF FALSE WHITE TEAK SEEDS AND COST ANALYSIS PERSPECTIVE IN BANGLADESH

Abdur Razzak Khan — 2026-06-30

The increasing demand for sustainable energy and the urgent need to reduce greenhouse gas emissions have intensified research into biodiesel as an alternative to fossil diesel. Non-edible oilseed resources, such as False White Teak (FWT) seeds, offer a promising and sustainable feedstock that does not compete with food supplies. However, the high viscosity and density of crude FWT oil limit its direct use in diesel engines. In this study, biodiesel was produced from FWT oil via alkali-catalysed trans-esterification, and process parameters were optimized to enhance fuel quality and yield. Trans-esterification was conducted at 60 °C using oil-to-methanol molar ratios ranging from 6:1. The maximum biodiesel yield of 78.70% was obtained at a 6:1 ratio. In contrast, lower ratios were evaluated to examine phase separation and soap formation. The produced biodiesel was purified and characterized according to ASTM D6751 standards. The fuel exhibited a density of 867 kg/m³, kinematic viscosity of 4.2 cSt at 40 °C, calorific value of 35 MJ/kg, flash point of 119 °C, fire point of 127 °C, and moisture content of 0.05%, demonstrating good compliance with ASTM D6751 standards biodiesel specifications. In addition, a simplified life cycle cost analysis revealed that the estimated biodiesel production cost was competitive with conventional diesel when by-product recovery was considered, highlighting its techno-economic feasibility. These results demonstrate that FWT oil is a viable non-edible feedstock for biodiesel production, offering both technical and economic potential for sustainable biofuel development in emerging economies.

DESIGN AND PERFORMANCE IMPROVEMENT OF TRIPLE-BAND MICROSTRIP PATCH ANTENNA FOR WIRELESS COMMUNICATIONS

Abdur Razzak Khan — 2026-06-30

Microstrip patch antennas have gained widespread attention due to their low fabrication cost, lightweight structure, and simple design. However, multiband antennas often suffer from limited bandwidth, low gain, and poor directivity. This study proposes a compact triple-band microstrip patch antenna integrated with a defected ground structure (DGS) to enhance its electromagnetic performance. The antenna is designed on a Flame Retardant 4 (FR4) substrate with dimensions of 40 by 40 by 1.6 mm³, where multiple DGS patterns are implemented on the ground plane to improve return loss, gain, and directivity. The proposed design operates efficiently at 2.4 GHz, 5.8 GHz, and 7.5 GHz frequency bands. Simulation results obtained using Computer Simulation Technology (CST) Microwave Studio demonstrate significant performance enhancement, with return loss improvements of 33.84 dB at 2.4 GHz, 62.46 dB at 5.8 GHz, and 51.28 dB at 7.5 GHz compared to a conventional patch antenna. In addition, the antenna provides gain values ranging from 4.20 to 5.57 dBi and directivity values from 4.96 to 7.36 dBi, demonstrating enhanced radiation characteristics compared with the conventional antenna. The DGS effectively redistributes the surface current, creating multiple resonant modes while improving impedance matching and radiation performance. These characteristics make the proposed antenna suitable for Wireless Fidelity (Wi-Fi) (2.4 GHz), Wireless Local Area Network (WLAN) (5.725–5.825 GHz), and satellite communication (7.24–7.575 GHz) applications.

HYDROLOGICAL SAFETY ASSESSMENT OF SMALL DAMS IN PINANG ISLAND UNDER UPDATED PMP/PMF AND CLIMATE CHANGE SCENARIOS

Wang Fook Pan — 2026-06-30

Probable Maximum Precipitations and Floods (PMPs/PMFs) are the hydrological loading criteria for contemporary dam/reservoir design and operation and maintenance (O&M) inspection programs. These parameters are dynamic and strictly desirable for safety of high hazardous infrastructure. The spillway safety rule and protocol are being tightened over the years. This study evaluates the overtopping hazards/potentials of both Air Itam (1962, 5.6 km²) and Teluk Bahang (1999, 10 km²) dams using three sets of PMP series (1) coastal PMP set (SMHB 1992,1994) adopted mainly in the past design studies, (2) current update and results of a nationwide PMP study by NAHRIM in 2008, and (3) PMPs with incorporation of an adjustment factor to account for climate change scenario by NAHRIM in 2013. This study has demonstrated primarily inadequate spillway capacity for Air Itam dam which was designed in the 1960’s without the benefit of adequate spillway sizing based on recent PMP/PMF methodology. Under both recent PMP/PMF loadings derived from a nationwide study (NAHRIM 2008) and climate change (NAHRIM 2013) scenarios, the existing morning glory spillway is inadequate for safe passage of PMP/PMF. It is recommended that retrofitting the existing spillway capacity should be considered as an urgent matter. Teluk Bahang dam designed and built in the late 1990’s was deemed adequate in its spillway capacity conforming to the contemporary PMP/PMF foresight. The dam is equipped with provision of ample headroom and anti-cavitation measures as additional margin of safety.