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Item type:Publication, Access status: with files , A cellular automata framework to study the diffusion in single and binary solvent systems(Nature Publishing Group, 2026-10-06); ; ; In this work, we present a two-dimensional cellular automata (CA) model to study mass transfer by diffusion of molecules in single and binary solvent systems. The method builds on Vanag’s probabilistic cellular automata (PCA), where diffusion is simulated through stochastic exchange of molecules between neighboring cells. While the original PCA framework effectively models single component diffusion driven by concentration gradients, it could not account for variable diffusion coefficients. We address this limitation by generalizing the PCA approach to handle binary systems, enabling the simulation of diffusion in heterogeneous materials with varied transport properties. This extension broadens the applicability of CA-based methods for capturing complex diffusion dynamics.Publicationtype: Journal Article12 15 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Adsorption behavior of lead and chromium onto MgO impregnated biochar derived from banana peels and rice husk in binary environment(Nature Publishing Group, 2026-07-16); ; 10 5 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Widespread shift toward extreme dominated precipitation with pronounced trends in arid and mediterranean regionsUnderstanding how precipitation extremes evolve relative to total precipitation has important implications for hydrology, water resources, and climate risk management. While previous studies have assessed trends in total precipitation and extremes separately, the changing balance between them remains underexplored globally. Here, we use the Extreme Precipitation Fraction (EPF)—the ratio of a year’s wettest daily precipitation event to its total annual precipitation—as a physically meaningful metric to quantify the dominance of extremes within annual rainfall totals. Using an ensemble of 25 CMIP6 global climate model simulations from the NASA NEX-GDDP dataset, we examine historical EPF patterns, projected trends under the high-emissions scenario. A first-order relative-change decomposition is then used to quantify the separate contributions of annual maximum daily precipitation and total annual precipitation to EPF trends. Results show that, historically, EPF values are highest in hot and cold deserts, where a single event contributes over 13–15% of annual rainfall, and lowest in tropical rainforest and monsoon zones (< 4%). Projected trends show a global shift toward more extreme-dominated regimes, particularly in dryland and Mediterranean climates. EPF increases exceed + 0.2 per decade in Mediterranean zones, where over 70% of grids show positive trends above + 0.1. In contrast, polar and high-latitude snow-dominated climates exhibit declining EPF values. Attribution of EPF trends to its individual contributions shows that changes in total annual precipitation dominate EPF trends in arid and Mediterranean regions (annual-maximum contribution < 45%), whereas changes in extreme precipitation contribute more strongly in humid temperate and monsoonal regions (> 54%). At high latitudes (> 67.5°N), changes in total precipitation account for more than 70% of EPF trends. These findings reveal that precipitation is increasingly delivered through fewer, more intense events in vulnerable regions, with implications for climate-risk assessment and adaptation planning.Publicationtype: Journal Article20 7 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Radar-based inspiratory-to-expiratory time ratio estimation: a validation study(Springer, 2026-03-04); ; ; Respiration is a key indicator of health and wellbeing, with metrics such as respiratory rate (RR), inspiratory time (TI), expiratory time (TE), and the inspiratory-to-expiratory time (I:E) ratio offering insights into conditions ranging from acute life-threatening and chronic diseases to symptom management. While traditional methods already measure these parameters with high accuracy, they still require contact-based sensors, limiting their practicality for continuous monitoring. This study evaluates radar as a non-contact alternative by validating multiple radar-derived respiratory metrics against impedance pneumography measurements in 30 healthy volunteers at rest. Synchronous recordings from both modalities were analysed to assess agreement across methods using descriptive statistics, scatter plots, modified Bland-Altman plots, and equivalence testing (TI: ±0.3 s, TE: ±0.3 s, RR: ±2 brpm, I:E ratio: ±0.2). Equivalence testing indicated high correlation (p ≤ 0.001***) across all metrics, with 81.8% (TI), 77.6% (TE), 97.2% (RR), and 85.7% (I:E ratio) of values within predefined bounds. These findings highlight radar's potential for continuous respiratory monitoring, particularly in medical fields where minimizing patient burden is essential as in palliative, post anaesthesia, and intensive care settings.Publicationtype: Journal Article29 13 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Optical push broom effect by a moving refractive index front in a silicon Bragg waveguideHere we report the first experimental demonstration of signal trapping by a refractive index front in a silicon waveguide with a periodic perturbation, the so-called optical push broom effect. The refractive index front generated by a fast pump pulse captures and confines the energy of a CW signal propagating with smaller group velocity near to the band gap of a Bragg grating introduced in the waveguide. The energy of the CW signal is shifted in frequency, accelerated to the front velocity and thus accumulated inside the front. In the experiment a 2 ps free carrier front was generated via two photon absorption of the pump in the silicon waveguide. It collects approximately a 30 ps long packet of the CW signal inside it. The presented effect can be utilized to compress signals in time and space.Publicationtype: Journal Article21 12 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Impact of mixing duration on growth and nutrient removal efficiency of scenedesmus sp. in a novel raceway pond system(Springer, 2026); ; Ullah, NadeemRaceway ponds are regarded as a popular and cost-effective method for microalgae cultivation; however, their performance is strongly influenced by hydrodynamic conditions. Conventional paddlewheel driven systems are restricted to low operating velocities to avoid culture spilling out which often leads to reduced mixing and stagnant zone formation. In this study, a raceway pond was designed with the inclusion of curved slits at the bent zones and submersible pump as an alternative mixing device to prevent culture overflow, improve flow stability and minimize dead zones. This novel integration of structural modifications and pump-based mixing represents a significant advancement over traditional paddlewheel systems by providing higher velocities, enhanced circulation and more uniform algal growth conditions. Experiments were conducted to evaluate the effect of mixing durations in 6 L raceway ponds under identical environmental conditions. The raceway systems permitted a broader velocity range (0.10–0.45 m s⁻¹) without spillage. The system with continuous 24 h mixing compared to 20 and 16 h mixing resulted in the highest biomass productivity of 1.01 g L⁻¹ d⁻¹ and maximum nutrient removal rates of 5.18 mg L⁻¹ d⁻¹ and 3.41 mg L⁻¹ d⁻¹ for NO₃⁻ and PO₄³⁻, respectively. Submersible-pump configured open raceway pond achieved comparable or higher biomass yield, lower energy consumption with a net energy efficiency of 62%, demonstrating its practicality and cost-effectiveness as a viable alternative to conventional paddlewheel driven systems for large-scale Scenedesmus sp. cultivation.Publicationtype: Journal Article30 14 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Spatial and temporal assessment of soil degradation risk in Europe(Nature Publishing Group, 2025-12-24); ; ; ; Soil degradation threatens agricultural productivity and ecosystem resilience across Europe, yet spatially consistent assessments of its intensity and drivers remain limited. In this study, we used Soil Degradation Proxy (SDP), that integrates four key indicators of soil degradation, including erosion rate, soil pH, electrical conductivity, and organic carbon content, to quantify soil degradation risk. Using over 38,000 LUCAS topsoil observations and a machine learning model trained on climate, land cover, topographic, soil parent material properties, and spectral variables, we map annual SDP values between years 2000 to 2022 across Europe. Results show soil degradation risk is highest in southern Europe, especially in intensively managed and sparsely vegetated landscapes. Over the past two decades, approximately 7.1% of land area across the EU and the UK has experienced increasing degradation risk (most notably across Eastern Europe), with rainfed croplands emerging as the most affected land cover type. Land cover is the most influential driver, modulating effects of climatic variables such as precipitation and temperature on SDP. This data-driven framework provides a consistent and scalable approach for monitoring soil degradation risk and offers actionable insights to support targeted conservation and EU-wide policy implementation.Publicationtype: Journal Article21 18 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Microplastic-induced alterations in water flow and solute transport dynamics in soil(Springer, 2025-12-01); ; ; ; The growing use of plastic-based practices in agriculture has led to a significant accumulation of plastic waste in soil. Microplastics (MPs) increasingly threaten soil health and fertility by disrupting its physical and chemical environment, and impairing essential ecological functions. We conducted laboratory column measurements combined with microfluidic experiments to assess the effects of MPs on water flow and solute transport in soil, key processes for sustaining soil water and nutrient availability and thus crop growth and yield. Changes in hydraulic conductivity and solute breakthrough curves in sandy soils were investigated in the presence of varying concentrations of polyethylene (PE) and polyvinylchloride (PVC) microplastics. Alterations in pore structure and clogging of pore throats by MPs, as further evidenced through confocal and fluorescence microscopy of synthesized porous media, led to 39% and 74% reductions in hydraulic conductivity of sand samples containing 5% PVC and 5% PE, respectively. Solute transport experiments using a brine tracer revealed broader breakthrough curves in the presence of MPs. Overall, the enhancement of pore-scale flow heterogeneity driven by the development of preferential flow paths and the formation of low-permeability zones increased hydrodynamic dispersion and resulted in both early breakthrough and delayed transport of the tracer within the soil column.Publicationtype: Journal Article14 26 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Water storage paradox of reservoir expansion and evaporative losses in the MENA region(Nature Publishing Group, 2025-12-01); ; ; ; Prolonged droughts and population growth have increased the demand for efficient water storage globally. Small agricultural reservoirs support local water demands, but high evaporation rates particularly in dry regions undermine their storage effectiveness. Integrating fine-resolution Sentinel-2 imagery and physical modeling, we created an annual dataset of small agricultural reservoirs (< 0.1 km2) in the Middle East and North Africa (MENA) and quantified their associated evaporative losses from 2016 to 2023. We identified over 133,700 reservoirs, peaking in 2020, providing a combined surface area of 1,408 km2. The largest cumulative areas are located in Türkiye (309 km2), Pakistan (234 km2), Iran (168 km2), Iraq (108 km2), and Egypt (64 km2). Small agricultural reservoirs offer a storage capacity of 1,243 million cubic meters, accounting for up to 16% of irrigation and livestock water use in most MENA countries. Annual evaporative losses from these reservoirs may potentially exceed 2,400 million cubic meters with hotspots of cumulative evaporation corresponding to regions with the highest reservoir surface area, including southern Pakistan, southwestern Iran, and southeastern Iraq. Our analysis suggests strong climatic and anthropogenic influences on the expansion of reservoirs and their storage efficiency emphasizing the need for mitigation strategies to improve agricultural water security in water-stressed regions.Publicationtype: Journal Article15 78 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Impact of surface treatments on the photocatalytic performance of anodic aluminum oxide templates(Nature Publishing Group, 2025-12-01); ; ; ; Nanostructured materials receive great interest nowadays due to their unique properties, increased surface areas, and superior performances with associated reduced material usage. However, directly nanostructuring functional materials themselves can be technologically challenging. Hence, nanostructured substrates such as anodic aluminum oxide (AAO) can serve as templates for depositing active materials. The templates’ chemical stability is crucial for accurately assessing functional materials. Since AAO structures incorporate electrolyte ions during anodization, their chemical stability is influenced by the subsequent processing after anodization. This work investigates the effect of various post-anodization modifications on the surface chemistry and photocatalytic performance of bare AAO structures. Treatments with H2O2 or H3PO4 can stabilize the photocatalytic performance of the AAO templates over consecutive measurements. XPS measurements indicate that such stabilization results from AAO surface chemistry alterations. Further, we explore the functionalization of these modified AAO templates with photocatalysts by atomic layer deposition. The photocatalytic performance of TiO2 as a chemically stable photocatalyst is not affected by the templates’ post-anodization treatment. In contrast, the performance of templates functionalized with Fe2O3 as an inherent chemically instable photocatalyst depends on the template stability. This work highlights the importance of chemically stable template materials for exploring the properties of new functional materials.Publicationtype: Journal Article31 17