Search Results (1,076)

The provision of potable water for armed forces at their operational sites necessitates a robust treatment chain to ensure the production of safe drinking water from potentially contaminated local water sources. Relying on single-use water bottles is not considered an eco-friendly option and on-site production may exhibit limited efficiency depending on the water contamination. This study therefore aimed to define a mobile processing chain that could efficiently produce drinking water on-site while offering a multi-barrier level of protection. To evaluate the system, contaminated water was prepared from different water sources and then spiked with various inorganic contaminants (metals, anions: Cl⁻, F⁻, I⁻, NO₂⁻, NO₃⁻, SO₄²⁻, CN⁻), organic contaminants (e.g., pesticides, petroleum hydrocarbons, polycyclic aromatic hydrocarbons, chlorinated solvents), and energetic compound (perchlorate) at levels ranging from 5 to 50 times the standard water quality criteria. A specific treatment process was defined optimized and evaluated at flow rates reaching 500 L/h. This treatment chain includes the following: a sediment filter, a greensand filter, a cation exchange resin, an anion exchange resin, an activated carbon adsorption filter, ultrafiltration, a UV lamp, and a reverse osmosis (RO) unit. This treatment system successfully met all water quality criteria, providing a reliable and effective alternative to an RO-only treatment regime. Full article

The purpose of this study was to evaluate how a multi-component soil conditioner consisting of zeolite, calcium carbonate, potassium humate, and Ascophyllum nodosum extract affects selected soil properties (physical, chemical, and water-related properties, as well as microbial and enzymatic properties) and the growth and grain yield of spring barley (Hordeum vulgare L.). To achieve the goal, one-year research experiments were conducted at three conventionally tilled sites, which were situated on farms across three geographically separate regions in the Kuyavian–Pomeranian Region of Midwestern Poland. Most of the chemical properties, namely, total organic C, total N, pH in KCl, cation exchangeable capacity (CEC), as well as exchangeable (Mg, Ca, K, and Na) and available (Mg, K, and P) forms of nutrients, were not significantly affected by the conditioner or sampling time. Independent of the study location, the percentage of macropores in total porosity (TP) and dissolved nitrogen content (DNt) determined in July were considerably greater in the soil treated with Solactiv compared to the reference soil. Bulk density (BD), in turn, showed the opposite tendency, also suggesting the positive effect of the studied conditioner. At all study sites, application of the conditioner significantly reduced the percentage of micropores in total porosity (TP) (by 17%), while significantly increasing the content of macropores in TP (15%) and enhancing the percentage of available and readily available water capacity (8.5% and 14%). No clear changes in the results of C and N form and enzymatic activity were noted. The activities of DHA and FDAH behave differently in each study site, making it difficult to draw clear conclusions. The cellulase was the only enzyme that was significantly and positively affected by Solactiv at all study sites and for both sampling times. The values of dry matter of roots and plants, barley root length and surface, and barley grain yield were considerably greater in soil amended with Solactiv compared to the reference soil. Because some important soil and plant properties showed a positive response toward the tested conditioner, despite the low dose used, further studies should be conducted at a larger scale, focusing on different soils and plants. Full article

Electrocatalytic water splitting offers a promising route to sustainable H₂, but the oxygen evolution reaction (OER) in alkaline media remains the principal bottleneck for activity and durability. This review focuses on alkaline OER and integrates mechanism, kinetics, materials design, and cell-level considerations. Reaction mechanisms are outlined, including the adsorbate evolution mechanism (AEM) and the lattice oxygen mediated mechanism (LOM), together with universal scaling constraints and operando reconstruction of precatalysts into active oxyhydroxides. Strategies for electronic tuning, defect creation, and heterointerface design are linked to measurable kinetics, including iR-corrected overpotential, Tafel slope, charge transfer resistance, and electrochemically active surface area (ECSA). Representative catalyst families are critically evaluated, covering Ir and Ru oxides, Ni-, Fe-, and Co-based compounds, carbon-based materials, and heterostructure systems. Electrolyte engineering is discussed, including control of Fe impurities and cation and anion effects, and gas management at current densities of 100–500 mA·cm⁻² and higher. Finally, we outline challenges and directions that include operando discrimination between mechanisms and possible crossover between AEM and LOM, strategies to relax scaling relations using dual sites and interfacial water control, and constant potential modeling with explicit solvation and electric fields to enable efficient, scalable alkaline electrolyzers. Full article

“Miloschite”, a chromium-containing halloysite with intense blue hues, was first discovered in 1835 in Rudnjak, Serbia. Some of the collected “miloschite” samples remained in Serbia and are kept in the University Collection of Minerals and Rocks (Faculty of Mining and Geology, University of Belgrade) and in the Natural History Museum in Belgrade. During the 19th and 20th centuries, numerous studies examined this mineral. From the original samples collected at the type locality—initially described as “miloschite” and later confirmed to be varieties of halloysite enriched in chromium—subsequent interpretations of the authors on similar material from other localities worldwide led to a misinterpretation of “miloschite” as chromium-bearing kaolinite. This reinterpretation now requires revision. This investigation was carried out on an original sample employing techniques such as powder X-ray diffraction, thermal and various spectroscopic methods, along with assessments of cation exchange capacity, specific surface area, and color determination. Analyses reveal that “miloschite” primarily consists of chromium-bearing halloysite, where chromium is evenly distributed on the microscale and fills octahedral sites within the clay lattice. This research aims to reaffirm the status of “miloschite” as a significant geoheritage material from Serbia and to preserve its nomenclatural integrity as the chromium variety of halloysite. Full article

Background: Intranasal (I.N.) vaccination holds promise to elicit mucosal immunity that counters respiratory pathogens at the site of infection. For subunit protein vaccines, immunostimulatory adjuvants are typically required. Methods: We screened a panel of 22 lipid-phase adjuvants to identify which ones elicited antigen-specific IgA with I.N. immunization of liposome-displayed SARS-CoV-2 receptor-binding domain (RBD). Results: Initial screening showed the TLR-4 agonist Kdo2-Lipid A (KLA) effectively elicited RBD-specific IgA. A second round of screening identified further inclusion of the invariant NKT cell ligands α-Galactosylceramide (α-GalCer) and its synthetic analog 7DW8-5 as complementary adjuvants for I.N. immunization, resulting in orders-of-magnitude-greater mucosal IgA response relative to intramuscular (I.M.) immunization. The inclusion of cationic lipids conferred capacity for mucosal adhesion and maintained immune responses. In K18 hACE2 transgenic mice, vaccination significantly reduced viral replication and prevented mortality from SARS-CoV-2 challenge. Conclusions: These results point towards the potential for the use of KLA and α-GalCer for I.N. subunit vaccines. Full article

Mediterranean ecosystems are highly susceptible to wildfires, and shifts in fire patterns pose a threat to biodiversity, soil stability, and overall ecosystem health resilience. Implementing prescribed burning as a management strategy to lower wildfire risk has been proposed, but its ecological impacts in Greece are not well understood. This study examines the relationship between fireline intensity during prescribed burning and plant water potential, as well as its effects on soil properties and plant biodiversity on Chios Island, Greece. Field experiments were carried out in representative ecosystems, where we measured flame length to determine fireline intensity. In addition, we gathered soil samples before and after the prescribed burning and evaluated plant diversity. Measuring leaf water potential gave us a better understanding of how plants respond physiologically to different seasonal and site conditions. Our findings revealed that prescribed burning typically boosted plant diversity after the fire, with Fabaceae and Asteraceae playing a key role in regeneration. However, the soil responses differed from one site to another. Some sites saw a decline in organic carbon and nitrogen, while others showed an increase in exchangeable cations like calcium and magnesium, highlighting the importance of site-specific results. Studies on plant water potential revealed seasonal fluctuations in stress, underscoring the importance of accounting for seasonality in prescribed burn planning. Overall, prescribed burning has the potential to enhance biodiversity and ecosystem recovery, while also reducing fuel loads. These results highlight the importance of ongoing, site-specific monitoring for developing sustainable fire management strategies in Mediterranean ecosystems. Full article

The effectiveness of periodate-assisted photocatalysis in removing the cationic dye Safranin O (SO) was evaluated using a UV/TiO₂/IO₄⁻ process operated at room temperature under near-neutral pH conditions. Under base conditions ([IO₄⁻] = 0.15 mM, [TiO₂] = 0.4 g/L, [SO] = 10 mg/L), the ternary system achieved a pseudo-first-order rate constant of 0.6212 min⁻¹, outperforming the UV/TiO₂ and UV/IO₄⁻ processes by approximately 21- and 29-fold, respectively. This yielded a synergy ratio of about 12 compared to the sum of the binary processes. Targeted quenching experiments revealed the operative pathways. Strong inhibition by ascorbic acid and phenol indicates that interfacial holes and ^•OH are key oxidants. Methanol caused a moderate slowdown, consistent with ^•OH and hole scavenging. Benzoquinone and oxalate suppressed removal by intercepting the electron and O₂^•− pathways, respectively. Dichromate markedly inhibited the process via optical screening and competition for electrons. Azide had little effect, suggesting a minor role for singlet oxygen. Matrix studies showed progressively slower kinetics from deionized water to mineral water to seawater. This was due to halides, sulfate, alkalinity, and TiO₂ aggregation driven by ionic strength. Additional tests confirmed that the dominant modulators of performance were humic acid (site fouling and light screening), chloride and sulfate (radical speciation and surface effects), nitrite (near-diffusion radical quenching), and bicarbonate at pH 8.3 (conversion of ^•OH to CO₃^•−). Nonionic surfactants (Tween 80, Triton X-100) also depressed SO removal through micellar sequestration and competitive adsorption on TiO₂. The study confirms the potential of UV/TiO₂/IO₄⁻ as a tunable AOP capable of delivering rapid and reliable dye degradation under a wide range of water quality conditions. The mechanistic mapping unifies two roles for IO₄⁻, an electron acceptor that inhibits recombination and a photochemical precursor of iodine centered and ^•OH radicals and connect these roles to the observed synergy and to the trend across deionized water, mineral water, and seawater. The scavenger outcomes assign the main oxidant flux to holes and ^•OH radicals with a contributory electron or O₂^•− branch from IO₄⁻ reduction. Full article

Membrane separation is a promising technology for emulsified wastewater treatment. However, conventional membrane often suffer from limitations such as low mechanical strength, the inherent “trade-off” effect between flux and separation efficiency, and poor antifouling properties. To address these challenges, we report a novel composite membrane (CFM-UiO-66-(COOH)₂) fabricated by in situ growth of functionalized UiO-66-(COOH)₂ on a mechanically robust collagen fiber membrane (CFM) substrate. The resulting composite leverages the inherent properties of the CFM, along with the controlled generation of charge-neutralization demulsification sites and size-sieving filtration layers from the UiO-66-(COOH)₂. This CFM-UiO-66-(COOH)₂ exhibited superwetting behavior and achieved efficient separation of cationic surfactant-stabilized oil-in-water micro- and nano-emulsions. Specifically, the CFM-UiO-66-(COOH)₂ achieved separation efficiencies exceeding 99.85% for various cationic O/W emulsions, with permeation fluxes ranging from 178.9 to 225.9 L·m⁻²·h⁻¹. The membrane also demonstrated robust antifouling properties, excellent acid/alkali resistance, high abrasion durability, and good biocompatibility. Importantly, stable performance was maintained over six consecutive separation cycles. These characteristics, combined with the electrostatic interactions between carboxyl groups on the UiO-66-(COOH)₂ and cationic contaminants, suggest that CFM-UiO-66-(COOH)₂ holds significant potential for practical and sustainable wastewater treatment applications. Full article

An optical remote sensing approach was developed to identify areas with high and low salinity within the mangrove swamp rice system in West Africa. Conducted between 2019 and 2024 in Guinea-Bissau, this study examined two contrasting rice-growing environments, tidal mangrove (TM) and associated mangrove (AM), to assess changes in vegetation dynamics, soil salinity concentration, and soil chemical properties. Field sampling was conducted during the dry season to avoid waterlogging, and soil analyses included texture, cation exchange capacity, micronutrients, and electrical conductivity (EC_e). Meteorological stations recorded rainfall and environmental conditions over the period. Moreover, orthorectified and atmospherically corrected surface reflectance satellite imagery from PlanetScope and Sentinel-2 was selected due to their high spatial resolution and revisit frequency. From this data, vegetation dynamics were monitored using the Normalized Difference Vegetation Index (NDVI), with change detection calculated as the difference in NDVI between sequential images (ΔNDVI). Thresholds of 0.15 ≤ NDVI ≤ 0.5 and ΔNDVI > 0.1 were tested to identify significant vegetation growth, with smaller polygons (<1000 m²) removed to reduce noise. In this process, at least three temporal images per season were analyzed, and multi-year intersections were done to enhance accuracy. Our parameter optimization tests found that a locally calibrated NDVI threshold of 0.26 improved site classification. Thus, this integrated field–remote sensing approach proved to be a reproducible and cost-effective tool for detecting AM and TM environments and assessing vegetation responses to seasonal changes, contributing to improved land and water management in the salinity-affected mangrove swamp rice system. Full article

A highly active Co/Beta catalyst was prepared via ion-exchange method, in which sodium cations in the beta zeolite framework were replaced by cobalt ions using an aqueous cobalt nitrate solution. Based on XRD, SEM, TEM, XPS, and nitrogen adsorption–desorption analyses, it was confirmed that cobalt species successfully took the place of sodium ions in beta zeolite, while the cobalt species diffused with a uniform dispersion. Strong electronic coupling between cobalt species and zeolite framework oxygen stabilizes Co²⁺ sites in the material. The catalysts perform high efficiency in dye Acid Orange II (AO7) degradation reactions, which gives more than 99.5% removal efficiency at room temperature and initial pH within 10 min under low catalyst dosage. The advantages of the Co/Beta catalyst are reasonably attributed to its maximized metal−zeolite synergistic efficiency. Full article

Although the power conversion efficiency of perovskite photovoltaics (PVs) has achieved significant progress, the operational stability is still a critical issue for their commercialization. Compared to inorganic semiconductor materials, organic species in perovskites are intrinsically unstable under long-term illumination, heat, and bias stresses. These organic species exhibit higher chemical reactivity, which can complicate the degradation mechanisms or model of perovskite PVs. In this review, we analyzed the types of chemical reactions for different organic species. The chemical instability mainly stems from the deprotonation of A-site ammonium cations, X-site halide ion migration, and oxidation of halide ions, which can even mutually influence one another. We systematically discuss the effect of this chemical instability on perovskite structure degradation under device operation. These special chemical evolutions will accelerate perovskite PVs’ degradation. Then, strategies to mitigate these reactions for enhanced operational stability are introduced. Despite substantial progress in the operational stability of perovskite PVs, achieving an operational lifetime comparable to crystalline silicon remains challenging. Therefore, a deep understanding of intrinsic perovskite structure degradation should become a research focus, contributing to improvement in the operational lifetime of perovskite PVs. Full article

Peanut (Arachis hypogaea L.) is an important oil and cash crop, but its growth and productivity are severely constrained by low-temperature stress. Growth-regulating factors (GRFs) are plant-specific transcription factors involved in development and stress responses, yet their roles in peanut remain poorly understood. In this study, we identified AhGRF3b as a direct target of ahy-miR396 using degradome sequencing, which demonstrated precise miRNA-mediated cleavage sites within the AhGRF3b transcript. Expression profiling confirmed that ahy-miR396 suppresses AhGRF3b via post-transcriptional cleavage rather than translational repression. Functional analyses showed that overexpression of AhGRF3b in Arabidopsis thaliana promoted leaf expansion by enhancing cell proliferation. Specifically, leaf length, width, and petiole length increased by 104%, 22%, and 28%, respectively (p < 0.05). Under cold stress (0 °C for 7 days), transgenic lines (OE-2 and OE-6) exhibited significantly better growth than Col-0, with fresh weight increased by 158% and 146%, respectively (p < 0.05). Effect size analysis further confirmed these differences (Cohen’s d = 11.6 for OE-2 vs. Col-0; d = 6.3 for OE-6 vs. Col-0). Protein–protein interaction assays, performed using the yeast two-hybrid (Y2H) system and 3D protein–protein docking models, further supported that AhGRF3b interacts with Catalase 1 (AhCAT1), vacuolar cation/proton exchanger 3 (AhCAX3), probable polyamine oxidase 4 (AhPAO4), and ACT domain-containing protein 11 (AhACR11), which are involved in reactive oxygen species (ROS) scavenging and ion homeostasis. These interactions were associated with enhanced CAT and PAO enzymatic activities, reduced ROS accumulation, and upregulation of stress-related genes under cold stress. These findings suggest that the ahy-miR396/AhGRF3b module plays a potential regulatory role in leaf morphogenesis and cold tolerance, providing valuable genetic resources for breeding cold-tolerant peanut varieties. Full article

Adsorption studies of ciprofloxacine (CPX) and lidocaine (LID) emerging contaminants were performed on two fibrous Mg clays from the Madrid basin and Senegal. The samples were characterized by X-ray diffraction, ICP major element analysis, infrared spectroscopy, thermal analysis, optical petrography, scanning and transmission electron microscopy, cation exchange capacity (CEC), and N₂-BET analysis. Two mineral assemblages were established. Assemblage 1 mainly consists of sepiolite and minor trioctahedral smectite, while assemblage 2 is mostly composed of palygorskite, which is associated with dioctahedral smectite. The sorption was fast and reached equilibrium in 2 h. Fibrous Mg clays showed a higher adsorption capacity for CPX than for LID in the conditions studied. CPX adsorption on sepiolite and palygorskite can be the result of the combination of various mechanisms: ion exchange with permanently charged sites, electrostatic attractions with external surfaces, and an inner sphere complex with broken edges. LID adsorption mainly occurs by ion exchange and electrostatic interaction with the external surfaces of the clays. Dioctahedral smectite, as an associated phase, contributed to a higher removal percentage in palygorskite samples. By contrast, the trioctahedral smectite did not play a significant role in the adsorption of the samples with sepiolite. The mesoporous structure, high surface area, and moderate cation exchange of fibrous clays play a key role in the sorption process of CPX and LID. Full article

Landslides are a major natural hazard capable of causing severe damage to infrastructure, ecosystems, and human life. They result from complex interactions of geological, hydrological, and environmental factors, with soil properties playing a crucial role by influencing the mechanical behavior and moisture dynamics of slope materials that drive initiation and progression. In South Africa, few studies have examined soil influences on landslide susceptibility, and none have been conducted in the Eastern Cape Province. This study investigated the role of soil physical and chemical properties in landslide susceptibility by comparing profiles from landslide scars and stable sites in the Port St. Johns and Lusikisiki region. Samples from topsoil and subsoil horizons were analyzed for soil organic matter (SOM), cation exchange capacity (CEC), saturated hydraulic conductivity (Ksat), exchangeable sodium adsorption ratio (SARexc), and texture. Statistical analyses included the Shapiro–Wilk test to evaluate data normality. For inter-profile comparisons, Welch’s t-test was applied to normally distributed data, while the Mann–Whitney U test was used for non-normal distributions. Intra-profile differences across more than two groups were assessed using the Kruskal–Wallis test for the non-normally distributed data. Results showed that landslide-prone soils had higher SOM, CEC, and Ksat in topsoil, promoting moisture retention and rapid infiltration, which favor pore pressure build-up and slope failure. Non-landslide soils displayed higher sodium-related indices and finer textures, suggesting more uniform water retention and resilience. Vertical variation in landslide soils indicated hydraulic discontinuities, fostering perched saturation zones. Findings highlight landslide initiation as a product of interactions between hydromechanical gradients and chemical dynamics. Full article

Alkali metal-modified M-ZSM-5 zeolites (M: Li⁺, Na⁺, K⁺) were synthesized by cationic exchange and characterized using ICP-MS, XRD, N₂ adsorption–desorption, Py-IR and NH₃-TPD techniques to evaluate their elemental composition, structure, textural and acidic properties. In addition, XPS and DFT calculations were employed to study the effects of metal ion doping on the electronic structure and catalytic behavior. The latter catalytic performance was assessed in the methanol-to-olefin (MTO) reaction. The results showed that alkali metal doping facilitated the enhancement of the zeolite structural stability, adjustment of acid density, and increase in the adsorption energy of light olefins onto the active sites. During the reaction, olefin products shifted from Brønsted acid sites to alkali metal sites, effectively minimizing hydrogen transfer reactions. This change in the active site nature promoted the olefin cycle, resulting in higher yields in propylene and butylenes, reduced coke deposition, and prolonged catalyst lifetime. Among all zeolites, Li-exchanged ZSM-5 exhibited the best and extending the catalyst lifetime by 5 h. Full article