Current Issue : October-December Volume : 2026 Issue Number : 4 Articles : 5 Articles
The productivity of conventional solar stills simple devices used to obtain potable water from saline or brackish resources depends strongly on both the salinity of the feed water and the geometric characteristics of the unit. The present work examines the influence of these two parameters on still performance, with particular emphasis on how variations in salt concentration modify the efficiency of freshwater production. A numerical investigation is carried out for a conventional solar still operating under the climatic conditions of Agadir, using local profiles of solar irradiance, wind speed and ambient temperature as inputs. The system is described by energy balance equations applied to the main components of the distillation unit, and the coupled nonlinear differential equations are integrated using a fourth-order Runge-Kutta method. On this basis, the effects of seawater salinity and key operating conditions on the instantaneous and daily yield, as well as on overall solar still dimensions, are systematically analyzed....
Bat populations are facing numerous challenges due to human activities, and the development of solar energy in agricultural landscapes may add to these issues. Effects of solar fields on bat populations are still poorly understood. In this study, we compared bat activity in six solar fields that each had two grassland controls (agricultural grassland and natural meadows). Using passive bat detectors, bat calls were recorded along the edges of these plots, where the highest bat species diversity and activity were expected. The effects of landscape composition and configuration on the diversity, presence, and activity of different bat species were evaluated for each plot type at yearly, seasonal, and monthly scales. All seven bat species studied were less active in the solar fields compared to the two grassland controls. Specifically, both the number of nights that bats were present and the activity of bats were reduced in solar fields. As the number of solar fields keeps increasing in the agricultural landscape, it is thus essential to monitor their effect on the population levels....
The Brewer‐Dobson circulation (BDC) is a fundamental driver of trace gas transport in the middle atmosphere. Direct quantification of its descent rate remains observationally challenging. Here, we leverage wintertime solar proton events (SPEs) as natural experiments and use ozone‐depletion trajectories as dynamical tracers to quantify polar stratospheric descent. Derived velocities range from 150 to 570 m/day, consistent with CO/NO tracer studies and WACCM simulations. We find a strong relationship between descent velocity and integrated proton flux (CC = 0.54, p = 0.01), indicating that stronger particle precipitation is associated with enhanced polar descent of ozone‐depletion tracers. This relationship is accompanied by coherent changes in ozone, temperature, zonal wind, and planetary‐wave forcing. We further show that the SPE‐related dynamical responses differ between quasi‐biennial oscillation (QBO) phases, with stronger planetary‐wave forcing during the QBO westerly phase. These results provide observational constraints on the linkage between energetic particle precipitation and stratospheric dynamical variability....
The Sun produces a steady signal of high-energy gamma rays through interactions of Galactic cosmic rays (GCRs) with its atmosphere. Observations with the Fermi Large Area Telescope and the High Altitude Water Cherenkov Observatory have revealed a gamma-ray flux significantly higher than early theoretical predictions, with unexpected temporal and spectral features that suggest a crucial role of the solar magnetic field. In this work, we model GCR-induced gamma-ray emission at the solar disk using the CRPropa framework, with realistic hadronic interactions, chromospheric density profiles, and several magnetic field configurations over the solar cycle. This allows us to quantify the gamma-ray emission of the entire solar disk for different phases of the solar activity cycle, and we present, for the first time, maps of the production locations of gamma rays on the solar surface. We consider both monoenergetic and realistic power-law injection spectra in a simplified dipole– quadrupole–current-sheet model and potential-field source-surface extrapolations for Carrington rotations during solar maximum and minimum. Our results show that magnetic mirroring and large-scale field topology strongly affect the spectral shape and spatial distribution of the emission, with slightly enhanced fluxes predicted at solar minimum. While our simulated baseline fluxes remain below observations, additional effects—such as heavier nuclei, Parker field mirroring, and deeper atmospheric interactions—could result in further enhancements of fluxes closer to observational values. Hadronic interactions not only produce gamma rays but also neutrinos. We estimate the expected neutrino flux from the Sun based on our predictions. We find that the expected flux is slightly below current upper limits from IceCube....
Maximising the energy yield of perovskite solar cells (PSCs) through bifacial architectures is a promising route toward commercialisation. However, optimising charge extraction at the interfaces remains a critical challenge. In this study, we systematically compare tin dioxide (SnO2) and titanium dioxide (TiO2) electron transport layers (ETLs) in bifacial guanidinium-incorporated PSCs with a transparent gold (10 nm) back electrode. While the bulk perovskite crystallinity remains invariant on both substrates, SnO2 provides a distinct optical advantage through enhanced UV-blue transmittance. Beyond these optical benefits, comprehensive recombination process analyses reveal that SnO2 drastically suppresses nonradiative recombination. The SnO2 layer effectively mitigates defect states, significantly reducing both bulk and surface trap-assisted recombination rates without disrupting intrinsic bimolecular charge transport. Ultimately, these findings underscore the critical importance of rational interfacial engineering to neutralise defects, proving SnO2 to be an indispensable component for realising highly efficient and commercially viable bifacial perovskite optoelectronics....
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