Physical Science International Journal

Design and Construction of Remote Control Gate Cross Bar

M. E. Ishaje, N. A. Akonjom, E. O. Obi, B. Yahweh — Sat, 01 Aug 2026 00:00:00 +0000

Manual operation of barriers at access points can increase operator workload and may delay vehicular movement. This study designed, constructed, and evaluated a remote-controlled gate cross bar intended to provide a low-cost wireless alternative for automated access control. The system integrated an Arduino Uno microcontroller based on the ATmega328P, a 433 MHz radio-frequency transmitter and receiver, a 12 V DC geared motor, a motor-driver module, limit switches, relay control, status indicators, and a mechanical barrier arm. The control program processed remote commands, activated bidirectional motor movement, and used limit-switch feedback to stop the barrier at the fully open and closed positions. Performance was evaluated under outdoor conditions using 20 opening-and-closing cycles. The measured parameters included response time, opening time, closing time, remote operating range, and operational consistency. The system recorded a mean response time of 0.61 ± 0.05 s, a mean opening time of 2.43 ± 0.08 s, and a mean closing time of 2.48 ± 0.07 s. Stable RF communication was maintained over an average distance of 25 ± 1.2 m. Temporary electromagnetic interference, metallic obstacles, reinforced-concrete walls, and minor power-supply fluctuations affected signal reception or motor speed during some observations. No mechanical failure, motor overheating, excessive vibration, or structural deformation was reported during testing. The developed prototype demonstrated the practical integration of locally available mechanical and electronic components for wireless gate operation, although further evaluation under broader field conditions is required.

Geoeffectiveness of Interplanetary Storm Drivers during Solar Cycle 25 through June 2026: A Comparative Study of ICMEs, Sheath Regions, and Corotating Interaction Regions

Praveen Tyagi, V. K. Mishra — Fri, 07 Aug 2026 00:00:00 +0000

This study presents a cycle-to-date classification and geoeffectiveness analysis of the interplanetary drivers of geomagnetic storms during Solar Cycle 25 (SC25), from December 2019 to 24 June 2026. Hourly OMNI solar-wind plasma and interplanetary magnetic-field data were analysed together with the Dst, Kp, and AE indices. A total of 111 storms with minimum Dst <= -50 nT were identified and assigned to interplanetary coronal mass-ejection (ICME) ejecta or magnetic clouds, sheath regions, combined sheath-plus-ejecta (S+E) structures, or corotating interaction region/high-speed-stream (CIR/HSS) drivers. The catalogue contains 86 moderate, 19 intense, five superintense, and one extreme storm. S+E structures account for 65 storms and 23 of the 25 storms at intense or stronger levels (92%), including all six superintense-or-extreme events. CIR/HSS storms (n = 28) are almost exclusively moderate. Across the full sample, minimum Dst is most strongly associated with peak southward IMF Bz (r = 0.85) and maximum dynamic pressure (|r| = 0.80); the Bz-Dst relationship is tighter for S+E events (r = 0.87) than for CIR/HSS events (r = 0.52). The relative CIR/HSS contribution increases during the declining phase, while ICME-related activity remains substantial. A constant-coefficient linear Burton-type model provides limited pooled hindcast skill, particularly for CIR/HSS storms. A nonlinear threshold-injection formulation with driver-dependent decay scaling, calibrated on pre-2025 storms and evaluated on 2025-2026 storms, yields correlations of r = 0.86-0.91 and prediction efficiencies of 0.74-0.81 across the principal driver classes. Storm-level cross-validation and sensitivity testing indicate that these cycle-to-date conclusions are not driven by a single fitting split or by the uncertain classification of moderate storms. Because the analysis concerns one incomplete solar cycle and relatively few extreme events, the inferred S+E dominance should be treated as an SC25-specific finding requiring confirmation across additional cycles.

Analytical Investigation of Energy and Mass Transport in Magnetohydrodynamic Fe₃O₄–Water Nanofluid Flow through a Chemically Reacting Porous Channel with Thermal Radiation

Ojo, Adetoye Solomon, Nwabuzor, Peter Onyelukachukwu — Mon, 10 Aug 2026 00:00:00 +0000

Magnetohydrodynamic (MHD) nanofluids have emerged as promising working fluids for advanced thermal management systems owing to their enhanced heat transfer capability and controllable transport characteristics under external magnetic fields. This study presents an analytical investigation of coupled energy and mass transport in Fe₃O₄–water nanofluid flow through a chemically reacting porous rectangular channel under the influence of thermal radiation. The novelty of the present work lies in the integration of established thermophysical property correlations for effective viscosity, thermal conductivity, and electrical conductivity with an analytical Laplace transform framework to investigate the combined effects of magnetic field, buoyancy, thermal radiation, nanoparticle volume fraction, and chemical reaction on transport phenomena in porous media. The governing momentum, energy, and concentration equations are formulated using the Buckingham π theorem to obtain the corresponding dimensionless model and are solved analytically using the Laplace transform technique, subject to the prescribed boundary conditions. The developed analytical solutions are employed to examine the influence of the governing dimensionless parameters on the velocity, temperature, and concentration distributions. The analytical results demonstrate that variations in nanoparticle volume fraction significantly modify the thermal and concentration fields through changes in the effective thermophysical properties of the Fe₃O₄–water nanofluid, while an increase in effective viscosity alters fluid momentum transport. The Hartmann number acts as a resistive parameter that suppresses the velocity profile through the Lorentz force, whereas the effects of thermal radiation and chemical reaction on the transport fields are shown to be consistent with the governing equations and the validated analytical solutions. Representative analytical results indicate that changes in the governing parameters produce measurable variations in the velocity, temperature, and concentration distributions under the investigated operating conditions. The proposed analytical model provides improved physical insight into coupled magnetohydrodynamic heat and mass transfer in chemically reacting porous media and offers a reliable theoretical framework for validating numerical models and supporting the design and optimisation of electronic cooling systems, porous thermal devices, energy conversion systems, and other engineering applications employing Fe₃O₄–water nanofluids.

Phase Change Materials for Passive Cooling of Sahelian Buildings: Integration Options and a Screening Assessment for Niger

Moumouni Guero Mohamed, Mousbahou Mahamane Nana Farida — Wed, 19 Aug 2026 00:00:00 +0000

Aims: The study aims to synthesise phase change material (PCM) classification and building-envelope integration techniques relevant to hot, arid climates, and to carry out a comparative techno-economic and environmental assessment of three candidate PCMs (a paraffin, a hydrated salt, and a water-urea eutectic) for passive thermal regulation of housing in Niger.

Study Design: Structured literature synthesis combined with a multi-criteria scoring assessment adapted from established PCM-selection methodology.

Methodology: Published thermophysical, economic and environmental data for the three PCMs were consolidated from the underlying laboratory/simulation study and cross-checked against the wider PCM building-envelope literature. Five techno-economic criteria (cost-effectiveness, durability, ease of maintenance, local availability, thermal stability) and five environmental criteria (embodied energy, carbon footprint, biodegradability, end-of-life recyclability, environmental risk) were each scored from 1 (least favourable) to 5 (most favourable) and combined into an unweighted composite index; an annualised areal cost was additionally computed from unit price, indicative areal loading and expected service life.

Results: Niger's electricity access rate (about 20% in 2023) is far below the sub-Saharan African average (about 53%) and the global figure (about 92%), underlining the case for passive rather than mechanical cooling. The water-urea eutectic scored highest on the techno-economic index (3.9/5) and on the environmental index (4.6/5), driven by low cost and local sourceability, but had the shortest expected service life (5-10 years); paraffin scored lowest on cost-effectiveness and on the environmental index (1.9/5) despite the best durability and thermal stability scores; the hydrated salt occupied an intermediate position throughout. Annualised areal cost, however, favoured paraffin's long service life enough to narrow the gap with water-urea considerably.

Conclusion: No single material dominates across all criteria, which argues against a one-size-fits-all recommendation. Paraffin suits applications where dynamic thermal performance and longevity are prioritised and where the budget allows; the water-urea eutectic suits cost- and carbon-constrained, shorter-horizon retrofits using locally available inputs; and the hydrated salt is a reasonable compromise where corrosion risk can be managed. These results give Nigerien designers and policymakers a first quantitative, climate-specific basis for PCM selection, ahead of the full life-cycle assessments that scaled deployment will eventually require.