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43 pages, 2568 KB  
Article
ANN-MILP Hybrid Techniques for the Integration Challenge, Power Management of the EV Charging Station with Solar-Based Grid System, and BESS
by Km Puja Bharti, Haroon Ashfaq, Rajeev Kumar and Rajveer Singh
Energies 2026, 19(8), 1988; https://doi.org/10.3390/en19081988 - 20 Apr 2026
Abstract
Smart power management practices are needed for a sustainable EV charging infrastructure due to the fast use of renewable energy resources. An innovative power management structure for a small grid-connected solar PV system-based AC and DC charging station, combined with a backup purpose [...] Read more.
Smart power management practices are needed for a sustainable EV charging infrastructure due to the fast use of renewable energy resources. An innovative power management structure for a small grid-connected solar PV system-based AC and DC charging station, combined with a backup purpose battery energy system (BESS), is demonstrated in this paper’s study. The sustainability transition is associated with integrating renewable energy resources with a battery storage system, providing a helpful solution for managing large power-demanding entities (EV, microgrid, etc.). In this study, a solar PV system takes 500 datasets (based on data availability or to prevent overfitting) of PV voltage, solar irradiance, and air temperature, and the performance of controlling for the maximum power point tracker by training these datasets using Levenberg–Marquardt (LM), which was implemented in the ANN toolbox and created this technique in MATLAB 2016 or Simulink. Also, using this technique for the estimation and forecasting of the datasets of solar PV systems and EVs obtains better results for achieving further targets. To enhance decision-making capability through optimized technique, we have to find it before forecasting PV power generation and EV datasets throughout the day (24 h). The optimized power flows among solar PV power generation, EV charging demand (including AC charging and DC fast charging), the BESS, and the utility/small grid under several priority operating scenarios. A famous technique for optimization, mixed-integer linear programming (MILP), is applied. In this technique, the objective function is used for the solution of problem formation and compliance with system constraints such as the power balancing equation, charging/discharging limits, SOC limits, and grid export/import exchange limits: basically, equality, inequality, and bounds limits. Optimized results show that the coordinated power flow operations are consented to by EV users, by prioritizing some key points, such as solar PV use at the maximum, reducing the grid power dependency, and the first power flow towards EV charging demand. The verified MILP-based solutions boost the maximum utilization of renewable energy resources, feasible EV charging demand, and scaling power flow among these entities. The key contribution of this study is suitable for different powered EV charging stations based on both AC and DC, with different ratings of EVs (including fast and slow charging). Most solar PV-based generation supports the EVCS and backup for ranking-wise BESS, and grid support for the EVCS. Also, the key contribution of hybrid techniques in this article is divided into two stages: in the first stage, an artificial neural network (ANN) is utilized for estimating the PV voltage at the maximum point and forecasting, while in the second stage, mixed-integer linear programming (MILP) employs optimal power management. Full article
18 pages, 4936 KB  
Review
pH as a Design Tool for Low-Molecular-Weight Hydrogelators: Triggers, Structural Control, and Orthogonal Assembly
by Rie Kakehashi
Gels 2026, 12(4), 344; https://doi.org/10.3390/gels12040344 - 20 Apr 2026
Abstract
Low-molecular-weight gelators (LMWGs) have attracted growing attention as versatile alternatives to conventional polymeric thickeners and gelators, owing to their ability to form three-dimensional fibrillar networks through non-covalent self-assembly and to undergo reversible sol–gel transitions in response to external stimuli. Among the various stimuli [...] Read more.
Low-molecular-weight gelators (LMWGs) have attracted growing attention as versatile alternatives to conventional polymeric thickeners and gelators, owing to their ability to form three-dimensional fibrillar networks through non-covalent self-assembly and to undergo reversible sol–gel transitions in response to external stimuli. Among the various stimuli that can be exploited, pH represents a particularly attractive trigger given its direct relevance to biological and physiological environments. This review focuses on three categories of pH-responsive LMWGs that have shown notable progress over the past decade yet remain relatively underexplored in the literature. First, N-oxide-type hydrogelators are discussed, with emphasis on amide amine oxide-based surfactants and pyridine-N-oxide frameworks. The pH-dependent protonation of the N-oxide moiety modulates intermolecular hydrogen bonding, thereby governing self-assembly and gel formation. The structural versatility of these gelators enables rational tuning of aggregate morphology and confers clear pH and temperature responsiveness. Second, recent advances in phenylboronic acid-based LMWGs are highlighted. Although boronic acid derivatives have long been studied as dynamic crosslinking units in polymeric hydrogels, 3-isobutoxyphenylboronic acid was recently identified as the first example of phenylboronic acid functioning as an LMWG, in which gelation is driven primarily by hydrogen bonding and pH responsiveness is exploited for stimuli-triggered gel disruption rather than gel formation. Third, pH-responsive orthogonal self-assembly systems are reviewed. Representative examples include multicomponent hybrid hydrogels combining pH-activated LMWGs with polymer gelators for controlled drug release, pH-triggered self-sorting of two LMWGs without any polymeric component, and bio-based orthogonal hydrogels composed of a glucolipid LMWG and cellulose nanocrystals. For each system, both advantages and remaining limitations are critically assessed. Collectively, this review aims to provide a timely overview of emerging trends in pH-responsive LMWG research and to offer perspectives on the rational design of next-generation stimuli-responsive soft materials. Full article
(This article belongs to the Section Gel Processing and Engineering)
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14 pages, 3637 KB  
Article
Effect of Sintering Temperature on Phase Evolution and Oil-Repellent Performance of TiO2–Carbon-Coated Stainless-Steel Mesh
by Kayla Laguana, Sonia Egenberger, Jack Tobin, Claudia Wong, Logan Lu, Jack G. Webster and Mingheng Li
Separations 2026, 13(4), 125; https://doi.org/10.3390/separations13040125 - 20 Apr 2026
Abstract
This study investigates how sintering temperature affects phase evolution, titanium carbide (TiC) formation, and oil-repellent performance in TiO2–carbon-coated 304 stainless-steel mesh for oil–water separation applications. Coated meshes sintered at 400, 500, 600, 700, and 800 °C were evaluated using gravity-driven oil [...] Read more.
This study investigates how sintering temperature affects phase evolution, titanium carbide (TiC) formation, and oil-repellent performance in TiO2–carbon-coated 304 stainless-steel mesh for oil–water separation applications. Coated meshes sintered at 400, 500, 600, 700, and 800 °C were evaluated using gravity-driven oil permeation tests with 5W-20 motor oil and oil contact-angle measurements, while coating morphology, composition, and phase evolution were characterized by SEM, EDS, and XRD. Sintering temperature strongly influenced coating structure and wettability. Among the tested conditions, the mesh sintered at 600 °C showed the highest oil contact angle (105°) and the highest initial oil retention efficiency (80%), indicating the most favorable balance between oleophobicity and coating stability within the tested range. XRD analysis showed that 600 °C corresponded to the onset of the anatase-to-rutile transition and the initial formation of TiC. These results suggest that intermediate sintering temperatures can provide a favorable balance between retention of beneficial anatase content and enhanced interfacial interaction within the TiO2–carbon coating. Within the tested conditions, 600 °C was the best-performing sintering condition among the temperatures examined for this coating system. Full article
(This article belongs to the Section Separation Science in Energies)
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19 pages, 15647 KB  
Article
Microstructure Evolution and Solute Segregation of Inconel 718 in Laser Additive Manufacturing: A Numerical and Experimental Investigation
by Hang Liu, Wenjia Xiao, Baolin Yan and Hui Xiao
Materials 2026, 19(8), 1642; https://doi.org/10.3390/ma19081642 - 20 Apr 2026
Abstract
The segregation of brittle Laves phases remains a critical bottleneck limiting the performance of additive manufacturing (AM) nickel-based superalloys. While its evolution is governed by complex transient physical fields within the melt pool, a quantitative kinetic correlation between processing parameters and microstructural features [...] Read more.
The segregation of brittle Laves phases remains a critical bottleneck limiting the performance of additive manufacturing (AM) nickel-based superalloys. While its evolution is governed by complex transient physical fields within the melt pool, a quantitative kinetic correlation between processing parameters and microstructural features is currently lacking. In this study, a high-fidelity multiphysics numerical model was developed to establish a cross-scale mapping logic of “Process-Physical Field-Microstructure” by dissecting the global distribution of temperature gradient (G) and solidification rate (R) along the quasi-steady-state melt pool boundary. It is revealed that increasing the scanning speed synergistically enhances R while compressing G. Beyond driving a transition from oriented columnar dendrites to refined mixed-dendritic structures, this shift effectively blocks the continuous enrichment channels of Nb and Mo elements by compressing the “kinetic time window” for solute redistribution. Consequently, the morphology of the Laves phase is forced to evolve from a continuous interconnected chain-like network into dispersed isolated particles. This research clarifies the kinetic essence of microstructural evolution under non-equilibrium solidification, providing critical physical criteria for the precise intervention of deleterious phases and the regulation of microstructural consistency in high-performance AM components. Full article
(This article belongs to the Section Metals and Alloys)
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32 pages, 7098 KB  
Article
Ground-Level Ozone Distribution Across Saudi Arabia: A Spatiotemporal Study (2003–2024)
by Ahmad E. Samman, Abdallah Abdaldym, Heshmat Abdel Basset and Mostafa Morsy
Sustainability 2026, 18(8), 4075; https://doi.org/10.3390/su18084075 - 20 Apr 2026
Abstract
Ground-level ozone (GLO3) poses a critical threat to public health and the success of the Saudi Green Initiative, yet its long-term spatiotemporal evolution across the Arabian Peninsula remains poorly constrained. Utilizing CAMS-derived mixing ratios (1000–850 hPa) from 2003 to 2024, this [...] Read more.
Ground-level ozone (GLO3) poses a critical threat to public health and the success of the Saudi Green Initiative, yet its long-term spatiotemporal evolution across the Arabian Peninsula remains poorly constrained. Utilizing CAMS-derived mixing ratios (1000–850 hPa) from 2003 to 2024, this study identifies a major systemic regime shift occurring in 2016–2017, marking a transition toward a more O3-enriched atmospheric state across Saudi Arabia. While the early study period was characterized by pronounced spatial heterogeneity, post-2017 diagnostics reveal a synchronized intensification of GLO3, particularly within the urban industrial belts of the Eastern and Western Provinces. Statistical trend metrics, including Mann–Kendall and regime-shift detection, show a persistent upward trend in GLO3 concentrations, most significantly during winter and over the southwestern highlands. These trends are robustly coupled with increasing boundary-layer height, temperature, and UV-B radiation, alongside shifting precursor stoichiometry (CO, VOCs, NOx) that separates titration-dominated from production-dominated regimes. Our results suggest that this mid-decade intensification reflects a convergence of anthropogenic forcing under Saudi Vision 2030 and shifting regional climatic drivers. By uncovering the transition from localized variability to kingdom-wide synchronization, this research provides a process-based foundation for targeted air quality management and the safeguarding of regional sustainability frameworks. Full article
(This article belongs to the Section Air, Climate Change and Sustainability)
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28 pages, 8935 KB  
Article
Wind-Sound Synergy and Fractal Design: Intelligent, Adaptive Acoustic Façades for High-Performance, Climate-Responsive Buildings
by Lingge Tan, Xinyue Zhang, Donghui Cui and Stephen Jia Wang
Buildings 2026, 16(8), 1615; https://doi.org/10.3390/buildings16081615 - 20 Apr 2026
Abstract
The building façade serves as the primary interface between the built environment and external climate, marking the transition from static regulation to dynamic response in climate-adaptive design. While existing research predominantly addresses periodic climatic elements such as temperature and solar radiation, the highly [...] Read more.
The building façade serves as the primary interface between the built environment and external climate, marking the transition from static regulation to dynamic response in climate-adaptive design. While existing research predominantly addresses periodic climatic elements such as temperature and solar radiation, the highly stochastic wind environment and its potential for internal acoustic problems remain systematically unexplored. This study investigates the acoustic modulation mechanism of building façades under dynamic wind conditions through a simulation-based methodology. The primary aim is to demonstrate the use of active control to mitigate the influence of fluctuating wind on the internal acoustic environment of buildings with open windows or semi-open boundaries, focusing on the coupling between stochastic wind fields and architectural acoustics in humid subtropical climates. We propose a wind-responsive adaptive acoustic façade system employing fractal geometry and configurable delay strategies, and develop a high-fidelity simulation framework to quantify how façade geometry and activation logic regulate acoustic parameters under varying wind conditions (1–8 m/s). Results indicate that: (1) support vector regression-based mapping of wind speed to delay strategies maintains key sound-field parameters (Lateral Fraction (LF), Speech Clarity (C50), and Early Decay Time to Reverberation Time ratio (EDT/RT30)) within 10% fluctuation across wind regimes; (2) fractal configurations achieve balanced wide-band (125 Hz–8 kHz) performance, with SPL fluctuation <3 dB, spectral tilt (+0.3 dB), and reverberation time slope <0.3; (3) configurational switching between column (high LF) and row (high C50) arrangements enables dynamic trade-off between spatial impression and speech clarity. This work establishes an integrated framework coupling wind dynamics, façade morphology, and acoustic modulation to regulate objective indoor acoustic parameters. Based on the simulated omnidirectional point-source model, the results show that key acoustic indicators remain stable across varying wind conditions, providing a theoretical and quantifiable basis for climate-responsive acoustic envelope design. Future work will include empirical prototype testing and listening tests to determine whether these simulated acoustic parameters translate into improved comfort and well-being for occupants. Full article
(This article belongs to the Special Issue Advanced Research on Improvement of the Indoor Acoustic Environment)
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19 pages, 6594 KB  
Article
Trend Assessment and Correlation Analysis of Thermal Indices, Snow Depth, and NDSI Across Elevational Gradient in the Alborz Mountain Range
by Bayan Khaledi, Manuchehr Farajzadeh and Yousef Ghavidel Rahimi
Geographies 2026, 6(2), 42; https://doi.org/10.3390/geographies6020042 - 20 Apr 2026
Abstract
The Alborz Mountain range, serving as the strategic water tower of the Iranian Plateau, is experiencing the accelerating impacts of climate change. Given the critical role of snow reserves in this region for water security, understanding the mechanisms of snow degradation in response [...] Read more.
The Alborz Mountain range, serving as the strategic water tower of the Iranian Plateau, is experiencing the accelerating impacts of climate change. Given the critical role of snow reserves in this region for water security, understanding the mechanisms of snow degradation in response to warming is essential. Aiming to investigate the divergent responses of snow cover and snow depth to extreme temperature indices, this study analyzes a 23-year time series (2001–2023) of ERA5-Land data and MODIS imagery across 11 elevation bands. To this end, trends and correlations among the Warm Spell Duration Index (WSDI), the Percentage of Warm Days (TX90p), the Normalized Difference Snow Index (NDSI), and Average Snow Depth (ASD) were assessed using the Modified Mann–Kendall (MMK) test, Generalized Linear Modeling (GLM), and Spearman’s rank correlation. The findings reveal elevational heterogeneity in the snow regime of the Alborz. Notably, the decline in spatial snow cover (NDSI) is primarily concentrated in the mid-elevation transition zone (2000 to 3000 m), whereas the reduction in snow depth (ASD) is a widespread phenomenon, observed even at high altitudes above 4000 m. A key innovation of this research is demonstrating the dominant role of heat frequency over heat duration; GLM results indicate that the TX90p index (frequency of warm days) has a much stronger negative correlation with the degradation of snow resources than WSDI. These results confirm the transition of the Alborz hydrological system toward instability, the upward shift in the snowline in the transition zone, and the invisible thinning of the snowpack at higher elevations. Full article
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24 pages, 20957 KB  
Article
Geochemistry and Ore Genesis of the Huoyanshan Cu-Zn Polymetallic Deposit, North Qilian Orogenic Belt, China: Constraints from Trace Element Compositions and Sulfur Isotopes
by Zaijia Zhang, Xiaogang Guo, Peiqing Hu, Bo Mai and Zhuang Wu
Minerals 2026, 16(4), 421; https://doi.org/10.3390/min16040421 - 19 Apr 2026
Abstract
The Huoyanshan Cu-Zn volcanogenic massive sulfide (VMS) deposit, located in the North Qilian Orogenic Belt, China, is of significant economic importance. This study provides new constraints on the ore-forming processes through high-resolution in situ trace element and sulfur isotope analyses of pyrite and [...] Read more.
The Huoyanshan Cu-Zn volcanogenic massive sulfide (VMS) deposit, located in the North Qilian Orogenic Belt, China, is of significant economic importance. This study provides new constraints on the ore-forming processes through high-resolution in situ trace element and sulfur isotope analyses of pyrite and sphalerite using LA-(MC)-ICP-MS. Petrographic and geochemical investigations identified three distinct generations of pyrite (Py l to Py III). Early-stage Py I and Py II are characterized by high trace element contents (Au, As, Bi, Cu, Pb), elevated Co/Ni ratios (>1–10), and enriched δ34S values (+4.98‰ to +7.47‰). These signatures indicate precipitation from high-temperature, reduced magmatic–hydrothermal fluids influenced by thermochemical sulfate reduction (TSR). Late-stage Py IIl exhibits markedly lower Co/Ni ratios (<0.1) and lighter δ34S values (+3.72‰ to 3.89‰). This geochemical shift reflects a transition toward a cooler, more oxidized environment driven by the incursion and mixing of ambient seawater as the hydrothermal system waned. Trace element geochemistry of sphalerite reveals an average crystallization temperature of 265.8 °C (derived from the “GGIMFis” geothermometer), consistent with fluid inclusion data and representing a thermal “snapshot” of the waning hydrothermal stage. Systematic discriminant analysis using Ga/In, Ge/In, and Co-Ni-As systematics further confirms a strong magmatic–hydrothermal affiliation. Full article
56 pages, 3551 KB  
Review
Pathways for Greenhouse Thermal Management’s Contribution to Net-Zero Food Production
by Samson Sogbaike, Celestina Ezenwajiaku, Amir Badiee, Chris Bingham and Aliyu M. Aliyu
Energies 2026, 19(8), 1975; https://doi.org/10.3390/en19081975 - 19 Apr 2026
Abstract
Decarbonising greenhouse food production requires improvements in thermal management, energy efficiency, and system integration. Greenhouse energy demand is shaped by coupled heat and mass transfer processes, particularly envelope performance, ventilation, and latent heat associated with humidity control. This article synthesises recent advances in [...] Read more.
Decarbonising greenhouse food production requires improvements in thermal management, energy efficiency, and system integration. Greenhouse energy demand is shaped by coupled heat and mass transfer processes, particularly envelope performance, ventilation, and latent heat associated with humidity control. This article synthesises recent advances in greenhouse microclimate control with emphasis on heat transfer, low-carbon heating and cooling, thermal storage, renewable and waste heat integration, and advanced modelling and control approaches. The review shows that humidity control and latent load management are primary drivers of winter energy use, as moisture removal through ventilation and dehumidification directly increases the sensible heating required to maintain indoor temperature setpoints. When assessed using realistic psychrometric relationships, ventilation and dehumidification can dominate peak heating demand and seasonal consumption. The performance of heat pumps, storage systems, semi-closed greenhouse concepts, and renewable heat pathways depends on how thermal loads are defined, how system boundaries are set, and how technologies are integrated in operation. Digital twins, predictive control, and hybrid physics-data models are increasingly used to manage variability in weather, energy prices, and infrastructure constraints. Greenhouse decarbonisation cannot be treated as a simple substitution of energy sources. System performance depends on coordinated design and operation, including heat recovery, moisture removal, and integration of supply technologies. Semi-closed and heat recovery-based configurations can reduce the ventilation–heating penalty and lower primary energy demand compared with vent-to-dry approaches. Long-term market projections suggest that the commercial greenhouse sector could expand substantially by 2050 under plausible growth scenarios, reflecting increased capital investment rather than a proportional rise in global food output. Net-zero greenhouse production is achievable through combined improvements in thermal management, electrification, and renewable energy integration. However, large-scale deployment depends on consistent modelling assumptions, credible economic assessment, and alignment with heat and CO2 supply infrastructure. The transition is therefore shaped by system integration and planning as much as by individual technologies. Full article
17 pages, 3036 KB  
Article
Calcination-Free Biosynthesis of Silica Nanoparticles from Residual Rice Husk Using Aspergillus niger
by Daniel Escorcia-Díaz, Sebastián García-Mora, Leidy Rendón-Castrillón, Margarita Ramírez-Carmona and Carlos Ocampo-López
Appl. Sci. 2026, 16(8), 3967; https://doi.org/10.3390/app16083967 - 19 Apr 2026
Abstract
In this study, composite silica-containing nanostructures were biosynthesized from residual rice husk through a fermentative process using Aspergillus niger at room temperature without calcination. The obtained nanostructures were initially characterized by UV–Vis spectrophotometry, Fourier-transform infrared spectroscopy (FTIR), and field-emission scanning electron microscopy (FE-SEM) [...] Read more.
In this study, composite silica-containing nanostructures were biosynthesized from residual rice husk through a fermentative process using Aspergillus niger at room temperature without calcination. The obtained nanostructures were initially characterized by UV–Vis spectrophotometry, Fourier-transform infrared spectroscopy (FTIR), and field-emission scanning electron microscopy (FE-SEM) to determine their optical and structural properties compared with chemically synthesized silica. The results demonstrated the successful formation of composite silica-containing amorphous nanostructures under ambient conditions without the use of calcination or mineral acids. UV–Vis analysis revealed intense absorption in the deep ultraviolet region, attributed to electronic transitions associated with Si–O–Si bonds within the amorphous silica network. FTIR analysis enabled the identification of functional groups present on the material surface, providing direct evidence of the nanostructures’ chemical composition. Additionally, FE-SEM micrographs showed that the rice husk surface after biosynthesis exhibited a rough and porous texture with a morphology consistent with the formation of composite silica-containing amorphous nanostructures, in agreement with the characteristic Si–O–Si vibrational bands observed in the FTIR spectra and the strong ultraviolet absorption detected by UV–Vis analysis. Full article
(This article belongs to the Special Issue Valorization of Agri-Food Waste Biomass)
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31 pages, 19415 KB  
Article
Integration of Multi-Gas Sensors and Aerial Thermography into UAVs for Environmental Monitoring of a Landfill
by Juan Francisco Escudero-Villegas, Macaria Hernández-Chávez, Bertha Nelly Cabrera-Sánchez, Gilgamesh Luis-Raya, Josué Daniel Rivera-Fernández and Diego Adrián Fabila-Bustos
Appl. Sci. 2026, 16(8), 3970; https://doi.org/10.3390/app16083970 - 19 Apr 2026
Abstract
Landfills are a significant source of atmospheric emissions associated with the decomposition of organic waste; however, conventional monitoring methods typically have limited spatial coverage. This study evaluates the use of an UAV-based system for the spatial characterization of gases associated with biogas emissions [...] Read more.
Landfills are a significant source of atmospheric emissions associated with the decomposition of organic waste; however, conventional monitoring methods typically have limited spatial coverage. This study evaluates the use of an UAV-based system for the spatial characterization of gases associated with biogas emissions at a municipal landfill. A DJI Matrice 350 RTK platform equipped with a Sniffer4D Mini2 multi-gas station and a Zenmuse H20T thermal camera were used. Four flight campaigns were conducted at an altitude of 20 m, with an acquisition frequency of approximately 1 Hz, recording total hydrocarbons (CxHy) as an indirect indicator of methane (CH4), carbon dioxide (CO2), carbon monoxide (CO), nitrogen dioxide (NO2), ozone (O3), sulfur dioxide (SO2), oxygen (O2), temperature, and relative humidity. The results showed a marked transition around 13:10 h, characterized by a simultaneous increase in CH4 equivalent and CO2, along with a decrease in NO2, O3, and SO2. Furthermore, CH4 equivalent and CO2 showed the highest positive correlation among the variables (r = 0.96). Spatial maps generated using ordinary kriging revealed more heterogeneous patterns, while the qualitative thermal orthophoto confirmed the site’s surface variability. Overall, the results demonstrate that the integration of multi-gas sensors and aerial thermography on UAVs is viable for the spatial monitoring of landfills. Full article
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33 pages, 29117 KB  
Article
Critical Transitions at the Campi Flegrei Resurgent Caldera via Multiplatform and Multiparametric Data
by Andrea Vitale, Andrea Barone, Enrica Marotta, Dino Franco Vitale, Susi Pepe, Rosario Peluso, Raffaele Castaldo, Rosario Avino, Francesco Mercogliano, Antonio Pepe, Filippo Accomando, Gala Avvisati, Pasquale Belviso, Eliana Bellucci Sessa, Antonio Carandante, Maddalena Perrini, Fabio Sansivero and Pietro Tizzani
Remote Sens. 2026, 18(8), 1240; https://doi.org/10.3390/rs18081240 - 19 Apr 2026
Abstract
Understanding how volcanic systems evolve over time is a major challenge due to their complex behaviour and constantly changing conditions. This study explores a novel approach to detecting significant changes in multiparametric signals of volcanic unrest by analysing how different types of data, [...] Read more.
Understanding how volcanic systems evolve over time is a major challenge due to their complex behaviour and constantly changing conditions. This study explores a novel approach to detecting significant changes in multiparametric signals of volcanic unrest by analysing how different types of data, such as ground deformation, gas emissions, temperature, and earthquakes, interact with each other. Focusing on the Solfatara–Pisciarelli volcano system, which is a more active area in the Campi Flegrei Caldera (Southern Italy), we used two advanced methods to identify critical transitions in the system: one to model the nonlinear relationships between variables, and the other to detect key moments when the system’s behaviour shifts. By including time delays between signals (LAG), we found that our model became much more accurate in identifying these changes. In contrast, models that ignored time lags showed higher uncertainty. The results highlight the importance and effectiveness of using integrated multivariate approaches such as Multivariable Fractional Polynomial Analysis (MFPA) and Global Critical Point Analysis (GCPA) to gain deeper insights into the systemic behaviour of the caldera and its temporal evolution within a complex area like the Campi Flegrei over the selected time period. Full article
(This article belongs to the Section Remote Sensing in Geology, Geomorphology and Hydrology)
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28 pages, 899 KB  
Review
The Hydrogen Economy: Progress and Challenges to Future Growth
by Ifeanyi Oramulu and Vincent P. Paglioni
Hydrogen 2026, 7(2), 51; https://doi.org/10.3390/hydrogen7020051 - 19 Apr 2026
Abstract
The rally to mitigate growing carbon emissions and climate change necessitates decarbonization strategies, with hydrogen emerging as a key candidate option across multiple sectors. This review examines the current state of the hydrogen economy, including production, implementation, and associated risks. Hydrogen’s versatility in [...] Read more.
The rally to mitigate growing carbon emissions and climate change necessitates decarbonization strategies, with hydrogen emerging as a key candidate option across multiple sectors. This review examines the current state of the hydrogen economy, including production, implementation, and associated risks. Hydrogen’s versatility in industry, transportation, and energy storage is highlighted, alongside the challenges of transitioning from fossil fuel-based production. It explores the current state of hydrogen technologies, differentiating between green, blue, and gray hydrogen production methods, and highlights advancements in production techniques like thermochemical water splitting. Key findings show that while green hydrogen offers the cleanest pathway, high production costs and infrastructure limitations remain significant barriers to widespread adoption. This study also addresses safety concerns and public perception, emphasizing the need for robust risk assessment methodologies and management approaches. Furthermore, this paper underscores the importance of technological innovations, such as high-temperature electrolysis and synergies with renewable energy sources, to enhance efficiency and sustainability. Policy recommendations include financial incentives, regulatory frameworks, and international cooperation to accelerate hydrogen adoption and balance its development with other low-carbon solutions. Full article
30 pages, 17661 KB  
Article
Combustion Evolution of Aviation Kerosene Pools in Confined Spaces Under Mechanical Negative Pressure
by Haoshi Sun, Jing Luo, Pincong Wu, Jizhe Wang, Yuxian Bing, Mengqi Yuan, Xijing Li, Yuanzhi Li, Xinming Qian and Qi Zhang
Fire 2026, 9(4), 174; https://doi.org/10.3390/fire9040174 - 19 Apr 2026
Abstract
This study experimentally investigates the combustion behavior of RP-3 aviation kerosene pool fires (300~800 mm) within a confined space, specifically focusing on the complex interaction between buoyancy-driven plumes and mechanical negative pressure ventilation. By integrating high-precision mass loss measurements with multiple characteristic parameters, [...] Read more.
This study experimentally investigates the combustion behavior of RP-3 aviation kerosene pool fires (300~800 mm) within a confined space, specifically focusing on the complex interaction between buoyancy-driven plumes and mechanical negative pressure ventilation. By integrating high-precision mass loss measurements with multiple characteristic parameters, this research uniquely characterizes the transition of energy feedback mechanisms under confined suction flow. Results show that ventilation enhances combustion intensity and compresses the fire cycle. For an 800 mm pool, the peak mass loss rate rose by 57.1%, from 16.71 g/s to 26.25 g/s. This enhancement stems from boundary layer thinning, which transitions the combustion from diffusion-controlled to kinetics-controlled. Ventilation also induces severe flame tilt with a non-monotonic trend. The tilt angle peaks at 84° for 600 mm pools but drops to 64° at 800 mm as buoyancy momentum increases. Additionally, an energy contrast of vertical cooling and horizontal heating was observed. Axial peak temperatures decreased by 20%, while downwind thermal radiation flux increased by up to 125%. The ventilation system essentially acts as a directional energy projector, shifting heat loads toward the downwind region. These findings support the optimization of fire safety and detection designs for industrial ventilation systems. This study experimentally investigates the combustion behavior of RP-3 aviation kerosene pool fires (300–800 mm) within a confined space, specifically focusing on the complex interaction between buoyancy-driven plumes and mechanical negative pressure ventilation. By integrating high-precision mass loss measurements with multi-point thermal and imaging diagnostics, this research uniquely characterizes the transition of energy feedback mechanisms under confined suction flow. Full article
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22 pages, 951 KB  
Article
Severity-Dependent Modulation of Red Blood Cell Aging Patterns in Preeclampsia: Insights from Calorimetry and Atomic Force Microscopy
by Svetla Todinova, Velichka Strijkova, Ariana Langari, Ina Giosheva, Emil Gartchev, Vesela Katrova, Alexey Savov, Sashka Krumova and Tania Pencheva
Int. J. Mol. Sci. 2026, 27(8), 3633; https://doi.org/10.3390/ijms27083633 - 18 Apr 2026
Abstract
Preeclampsia (PE) is associated with systemic oxidative stress and vascular dysfunction, yet its effects on red blood cell (RBC) stability and mechanics remain incompletely understood. Here, we investigate the structural and nanomechanical alterations of RBCs in third-trimester pregnancies complicated by non-severe and severe [...] Read more.
Preeclampsia (PE) is associated with systemic oxidative stress and vascular dysfunction, yet its effects on red blood cell (RBC) stability and mechanics remain incompletely understood. Here, we investigate the structural and nanomechanical alterations of RBCs in third-trimester pregnancies complicated by non-severe and severe PE, compared with normotensive controls. RBCs are analyzed using differential scanning calorimetry (DSC) to assess protein thermal stability and atomic force microscopy (AFM) to determine membrane elasticity (Young’s modulus) during in vitro aging. Linear mixed-effects models аre applied to evaluate the effects of disease severity, storage time, and their (group × storage time) interaction. DSC reveals that Band 3 and hemoglobin exhibited pronounced destabilization in PE, with severe cases showing earlier and larger reductions in transition temperatures and heat capacities, indicative of disrupted membrane–cytoskeletal interactions. AFM confirms that these molecular changes translate into functional consequences: control and non-severe PE RBCs show physiological softening over time, whereas severe PE RBCs undergo pathological stiffening. Statistical modeling demonstrates strong time, group, and interaction effects for both thermodynamic and mechanical parameters. Together, these findings identify the Band 3–hemoglobin macrocomplex as a primary target of PE-induced RBC alterations and suggest that combined thermodynamic–nanomechanical profiling can serve as a sensitive approach to detect early subclinical RBC damage not detectable by routine hematological tests. Full article
(This article belongs to the Section Molecular Pathology, Diagnostics, and Therapeutics)
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